Nothing Special   »   [go: up one dir, main page]

WO2019026495A1 - Light guide plate, area light source device, display device, and electronic apparatus - Google Patents

Light guide plate, area light source device, display device, and electronic apparatus Download PDF

Info

Publication number
WO2019026495A1
WO2019026495A1 PCT/JP2018/024675 JP2018024675W WO2019026495A1 WO 2019026495 A1 WO2019026495 A1 WO 2019026495A1 JP 2018024675 W JP2018024675 W JP 2018024675W WO 2019026495 A1 WO2019026495 A1 WO 2019026495A1
Authority
WO
WIPO (PCT)
Prior art keywords
guide plate
light
light guide
flat
degrees
Prior art date
Application number
PCT/JP2018/024675
Other languages
French (fr)
Japanese (ja)
Inventor
正太郎 渡辺
衛 矢部
Original Assignee
オムロン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2018009489A external-priority patent/JP2019029334A/en
Application filed by オムロン株式会社 filed Critical オムロン株式会社
Priority to CN201880030641.8A priority Critical patent/CN110622050A/en
Publication of WO2019026495A1 publication Critical patent/WO2019026495A1/en

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
    • F21S2/00—Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V5/00—Refractors for light sources
    • F21V5/04—Refractors for light sources of lens shape

Definitions

  • the present invention relates to a light guide plate, a surface light source device, a display device and an electronic device.
  • the light emitted from the light source is incident on the light guide plate and travels the inside of the light guide plate while being repeatedly reflected inside the light guide plate.
  • light incident on the light exit surface of the light guide plate is incident at an incident angle smaller than the critical angle, light is emitted from the light exit surface of the light guide plate to the outside.
  • the spread of the luminance of the light emitted from the light exit surface of the light guide plate is large, it is difficult to control the light emission luminance in the narrow width region in the local dimming control.
  • an object of the present invention is to suppress the spread of the luminance of light emitted from the light exit surface of the light guide plate.
  • the present invention adopts the following means in order to solve the above problems. That is, the present invention is a substantially flat light guide plate having a light incident surface to which light is incident on the side and emitting light incident from the light incident surface from the light emitting surface, and it has a flat portion and a flat portion.
  • the angle formed by the plane of the flat plate portion of the light guide plate and the tangent of the inclined surface at the end of at least one of the ridges and grooves is 30 degrees or more and 70 degrees or less. The spread of the luminance of the light emitted from the light exit surface of the light guide plate can be suppressed.
  • the angle formed by the flat surface of the flat plate portion and the tangent of the inclined surface at the end of at least one of the ridge and the groove may be 45 degrees or more and 60 degrees or less.
  • the inclined surface may include a curved surface.
  • the inclined surface includes a curved surface and a flat surface, and the angle between the flat surface and the flat surface at the end of at least one of the ridge and the groove is 30 degrees or more and 70 degrees or less Good.
  • the inclined surface includes a curved surface and a flat surface, and the angle between the flat surface and the flat surface at the end of at least one of the ridge and the groove is 45 degrees or more and 60 degrees or less Good.
  • the thickness of the light guide plate excluding at least one of the plurality of ridges and grooves may be 0.2 mm or more and 1.0 mm or less.
  • at least one of the plurality of convex lines and concave lines may be disposed on the flat surface of the flat plate without a gap.
  • At least one of the plurality of ridges and grooves is disposed on a flat surface of the flat plate portion at a constant interval, and the light exit surface is an inclined surface of at least one of the plurality of ridges and grooves. And a plane.
  • the present invention is a substantially flat light guide plate having a light incident surface on which light is incident on a side and emitting light incident from the light incident surface from a light emitting surface, and is a flat plate portion and a flat plate portion. And at least one of a plurality of ridges and grooves extending in a direction perpendicular to the light entrance surface, provided in a plane and viewed in a direction normal to the plane, at least one of the plurality of ridges and grooves At least one of the plurality of ridges and grooves is disposed on the plane at a predetermined interval, and at least one of the plurality of ridges and grooves has an inclined surface which is inclined with respect to the plane, and the light exit surface is at least a plurality of ridges and grooves It is a light guide plate which is formed by one inclined surface and a plane, and which makes an angle of 30 degrees or more and 80 degrees or less with a plane and a tangent of an inclined surface in at least one end of a ridge
  • At least one of the plurality of ridges and grooves is disposed at a constant interval on the flat plate portion of the light guide plate, and at least one of the flat surface of the flat plate portion and the ridges and grooves
  • a surface light source device includes the light guide plate according to the present invention, and a light source disposed at a position facing the light incident surface.
  • a surface light source device includes the light guide plate according to the present invention, a first light source, and a second light source, and the light incident surface is a first light incident surface and a second light incident surface. And the first light incident surface is opposite to the second light incident surface, the first light source is disposed at a position facing the first light incident surface, and the second light source is It is arrange
  • a display device includes the surface light source device according to the present invention, and a display panel that receives light emitted from the surface light source device.
  • An electronic device includes the display device according to the present invention.
  • the spread of the luminance of the light emitted from the light exit surface of the light guide plate can be suppressed.
  • FIG. 1 is a perspective view illustrating the configuration of the liquid crystal display device according to the embodiment.
  • FIG. 2 is a perspective view illustrating the configuration of the surface light source device according to the embodiment.
  • FIG. 3A is a view showing a light guide plate according to the embodiment.
  • FIG. 3B is a view showing a light guide plate according to the embodiment.
  • FIG. 4A is a view for explaining the relationship between the width of a light beam emitted from the upper surface of the light guide plate and the angle of the lenticular.
  • FIG. 4B is a view for explaining the relationship between the width of a light beam emitted from the upper surface of the light guide plate and the angle of the lenticular.
  • FIG. 4A is a view for explaining the relationship between the width of a light beam emitted from the upper surface of the light guide plate and the angle of the lenticular.
  • FIG. 4A is a view for explaining the relationship between the width of a light beam emitted from the upper surface of the light
  • FIG. 4C is a view for explaining the relationship between the width of a light beam emitted from the upper surface of the light guide plate and the angle of the lenticular.
  • FIG. 5A is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate.
  • FIG. 5B is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate.
  • FIG. 5C is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate.
  • FIG. 6 is a view showing the relationship between the luminance of light emitted from the upper surface of the light guide plate and the angle of the lenticular.
  • FIG. 5A is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate.
  • FIG. 5B is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate.
  • FIG. 5C is a view showing a luminance distribution of
  • FIG. 7 is an explanatory view of the full width half maximum of the luminance of light emitted from the upper surface of the light guide plate.
  • FIG. 8 is a diagram showing the relationship between the contrast ratio and the angle of the lenticular.
  • FIG. 9 is an explanatory view of the contrast ratio.
  • FIG. 10 is a diagram showing the luminance distribution of light emitted from the upper surface of the light guide plate.
  • FIG. 11 is a view showing the relationship between the thickness of the light guide plate, the contrast ratio, and the angle of the lenticular.
  • FIG. 12A is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate.
  • FIG. 12B is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate.
  • FIG. 13A is a view showing a light guide plate according to the embodiment.
  • FIG. 13B is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate.
  • FIG. 13C is a view showing a contrast ratio in a light guide plate in which a flat portion is not provided and a light guide plate in which a flat portion is provided.
  • FIG. 14A is a view showing a light guide plate according to the embodiment.
  • FIG. 14B is a view showing a light guide plate according to the embodiment.
  • FIG. 15 is a view showing a light guide plate according to the embodiment.
  • FIG. 16A is a view showing a light guide plate according to the embodiment.
  • FIG. 16B is a view showing a light guide plate according to the embodiment.
  • FIG. 17 is a view showing a light guide plate according to the embodiment.
  • FIG. 18 is a view showing a light guide plate according to the embodiment.
  • FIG. 19A is a view showing a light guide plate according to the embodiment.
  • FIG. 19B is a view showing a light guide plate according to the embodiment.
  • FIG. 19C is a view showing a light guide plate according to the embodiment.
  • FIG. 19D is a view showing a light guide plate according to the embodiment.
  • FIG. 19E is a view showing a light guide plate according to the embodiment.
  • FIG. 20A is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate.
  • FIG. 20B is a diagram showing the contrast ratio in the light guide plate.
  • FIG. 21A is a view showing a light guide plate according to the embodiment.
  • FIG. 21B is a view showing a light guide plate according to the embodiment.
  • FIG. 21C is a view showing a light guide plate according to the embodiment.
  • FIG. 22A is a view showing a light guide plate according to the embodiment.
  • FIG. 22B is a view showing a light guide plate according to the embodiment.
  • FIG. 22C is a view showing a light guide plate according to the embodiment.
  • FIG. 23A is a view showing a light guide plate according to the embodiment.
  • FIG. 23B is a view showing a light guide plate according to the embodiment.
  • FIG. 23C is a view showing a light guide plate according to the embodiment.
  • display device is described as a liquid crystal display device
  • surface light source device is described as a backlight unit of a liquid crystal display device.
  • the “surface light source device” may be used in applications other than a backlight unit, such as a front light disposed on the front of a display device or a display device made of electronic paper.
  • FIG. 1 is a perspective view illustrating the configuration of the liquid crystal display device according to the embodiment.
  • the liquid crystal display device includes a surface light source device 1 disposed as a backlight unit, and a display panel 2 that receives light emitted from the surface light source device 1.
  • the display panel 2 displays an image by applying a voltage to the liquid crystal sandwiched between the glass plates to increase or decrease the light transmittance.
  • the display panel 2 side may be described as the upper surface side, and the opposite surface side may be described as the lower surface side.
  • FIG. 2 is a perspective view illustrating the configuration of the surface light source device 1 according to the embodiment.
  • the surface light source device 1 according to the embodiment includes a light guide plate 10, a light source 11, a flexible printed circuit board (hereinafter also referred to as “FPC”) 12, a fixing member 13, and a frame 14.
  • the surface light source device 1 further includes a reflective sheet 15 disposed on the lower surface side of the light guide plate 10, a diffusion sheet 16 sequentially laminated on the upper surface side of the light guide plate 10, a prism sheet 17, and a light shielding double-sided tape 18.
  • the light guide plate 10 has a substantially flat plate shape, and is formed of a translucent material such as polycarbonate resin or polymethyl methacrylate resin.
  • the upper surface of the light guide plate 10 is a light emitting surface from which light is emitted, and is a surface facing the display panel 2.
  • the light guide plate 10 guides the light incident from the light source 11 into the light guide plate 10 to the light exit surface, and all or part of the light exit surface is illuminated.
  • the light guide plate 10 may include a light guide plate main body and a light introducing portion which is higher than the height of the light guide plate main body. The light emitted from the light source 11 efficiently enters the light guide plate main body from the light introducing portion, and the light use efficiency of the light guide plate 10 is improved.
  • the light guide plate main body is thinner than the light introducing portion, the reduction in thickness of the surface light source device 1 is improved, and the reduction in thickness of the liquid crystal display device including the surface light source device 1 is improved.
  • the light guide plate 10 according to the embodiment may have a flat plate shape without the light introducing portion.
  • the light source 11 emits white light from the fluorescent unit.
  • the light source 11 is, for example, an LED package, but a light source other than the LED package may be used.
  • the light source 11 is formed by sealing an LED chip, which is a light emitting element, with a translucent resin (resin layer) containing a phosphor.
  • the phosphor layer may be disposed on the light emitting surface of the light guide plate 10 without disposing the phosphor on the LED chip, or the phosphor layer may be disposed on the reflective sheet 15.
  • the light source 11 receives power supply from the FPC 12 and is driven to light.
  • LED light sources other than white may be used as the light source 11.
  • the light source 11 is disposed at a position facing the light incident surface of the light guide plate 10.
  • the light source 11 is mounted on the FPC 12 so that the light emitting surface of the light source 11 faces the light incident surface of the light guide plate 10.
  • a plurality of light sources 11 may be mounted on the FPC 12 in a row at regular
  • the FPC 12 is configured by providing a wiring with a conductor foil on a flexible insulating film base material, and adhering a cover lay or resin (photosensitive resin), which is an insulating film for protection, on the surface. It is a wiring board. Wiring is provided on the FPC 12. The wiring of the FPC 12 is used to supply power to the light source 11 or the like.
  • the fixing member 13 is disposed on the lower surface or the like of the FPC 12 and fixes the FPC 12 to the light guide plate 10.
  • the fixing member 13 is, for example, a double-sided adhesive tape whose upper and lower surfaces are adhesive surfaces.
  • the frame 14 accommodates the light guide plate 10, the light source 11, the FPC 12, the fixing member 13, the reflection sheet 15, the diffusion sheet 16, and the prism sheet 17.
  • the frame 14 may be a frame (frame-like member) surrounding the side surface of the light guide plate 10, or a box body having a frame surrounding the side surface of the light guide plate 10 and a bottom plate on which the frame is erected It may be a box-like member).
  • the frame may be formed by four side wall members, a circular side wall member having an opening, or an elliptical side wall member having an opening. Further, the corner portions of the side wall members on the four sides of the frame may have a right-angled shape, and the corner portions of the side wall members on the four sides of the frame may have an R shape.
  • the reflective sheet 15 is disposed in contact with the lower surface of the light guide plate 10.
  • the lower surface of the light guide plate 10 is a surface opposite to the upper surface of the light guide plate 10.
  • the reflection sheet 15 is a smooth sheet made of a high reflection film having a multilayer film structure, a white resin sheet having a high reflectance, a metal foil or the like, and light in the light guide plate 10 does not leak from the lower surface of the surface light source device 1 Reflect light.
  • the frame 14 is a box having a frame and a bottom plate
  • the reflective sheet 15 is disposed between the light guide plate 10 and the bottom plate of the frame 14.
  • a diffusion sheet 16 and one or two prism sheets 17 are disposed on the light guide plate 10.
  • the diffusion sheet 16 is a translucent resin film, and diffuses the light emitted from the light emitting surface of the light guide plate 10 to widen the directivity of light.
  • the prism sheet 17 is a transparent resin film on the upper surface of which a fine pattern in the form of a triangular prism is formed, and condenses the light diffused by the diffusion sheet 16 when the surface light source device 1 is viewed from the upper surface Increase the brightness.
  • the light shielding double-sided tape 18 is a black adhesive tape whose upper and lower surfaces are adhesive surfaces.
  • the light shielding double-sided tape 18 has a frame shape (ring shape).
  • the light shielding double-sided tape 18 is disposed along the outer peripheral portion of the frame 14 to suppress the leakage of light to the outside of the surface light source device 1.
  • Drawing 3A and Drawing 3B are figures showing light guide plate 10 concerning an embodiment.
  • the light guide plate 10 has an incident surface 20 on which the light emitted from the light source 11 is incident, and an exit surface on which the light incident from the incident surface 20 is emitted.
  • the light exit surface of the light guide plate 10 is directed to the display panel 2 side, and hereinafter, the light exit surface of the light guide plate 10 is the upper surface 21 of the light guide plate 10, and the surface opposite to the light exit surface of the light guide plate 10 The surface) is described as the lower surface 22 of the light guide plate 10.
  • the lower surface 22 of the light guide plate 10 is inclined approximately 90 degrees with respect to the light incident surface 20 of the light guide plate 10.
  • the light emitted from the light source 11 enters the inside of the light guide plate 10 from the light incident surface 20 of the light guide plate 10 and travels the inside of the light guide plate 10 while repeating total reflection on the upper surface 21 and the lower surface 22 of the light guide plate 10.
  • light incident on the upper surface 21 of the light guide plate 10 is incident at an incident angle smaller than the critical angle, light is emitted from the upper surface 21 of the light guide plate 10 to the outside.
  • the light guide plate 10 includes a flat plate portion 30 and a plurality of lenticulars 23 provided on the flat surface 31 of the flat plate portion 30.
  • FIG. 3B is a view showing the light guide plate 10 according to the embodiment, and FIG. 3B shows the light guide plate 10 as viewed from the light incident surface 20 side of the light guide plate 10.
  • the plurality of lenticulars 23 have curved surfaces 23A.
  • the curved surface 23A is inclined with respect to the plane 31. Therefore, the lenticular 23 has an inclined surface which is inclined with respect to the plane 31.
  • the upper surface 21 of the light guide plate 10 is formed by the curved surfaces 23A of the plurality of lenticulars 23.
  • Each lenticular 23 is a ridge extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 when viewed in the normal direction of the flat surface 31 of the flat plate portion 30. Therefore, the curved surface 23 A of the lenticular 23 protrudes from the plane 31 of the flat plate portion 30 in the normal direction of the plane 31 of the flat plate portion 30.
  • the plurality of lenticulars 23 are continuously arranged, and two adjacent lenticulars 23 are connected to each other. Therefore, the plurality of lenticulars 23 are disposed on the flat surface 31 of the flat plate portion 30 without a gap.
  • the width of the lenticular 23 (the length in the short direction of the lenticular 23) and the pitch of the lenticular 23 are the same.
  • the lenticular 23 may be integrally formed on the light guide plate 10 manufactured by injection molding.
  • FIGS. 4A to 4C are diagrams for explaining the relationship between the width of the light beam emitted from the upper surface 21 of the light guide plate 10 and the angle of the lenticular 23.
  • FIG. 4A and FIG. 4B show the light guide plate 10 as viewed from the light incident surface 20 side of the light guide plate 10.
  • the angle of the lenticular 23 shown in FIG. 4A is smaller than the angle of the lenticular 23 shown in FIG. 4B.
  • the angle of the lenticular 23 is the contact angle of the lenticular 23. That is, the angle of the lenticular 23 is an angle ( ⁇ ) formed by the flat surface 31 of the flat plate portion 30 and the tangent L1 of the curved surface 23A at the end of the lenticular 23 (see FIG.
  • the angle of the lenticular 23 decreases, the angle of the curved surface of the lenticular 23 with respect to the light incident on the upper surface 21 of the light guide plate 10 decreases, so the incident angle of light hardly exceeds the critical angle. Light is less likely to be emitted from Therefore, as shown in FIG. 4A, when the angle of the lenticular 23 decreases, the width W1 of the light beam emitted from the upper surface 21 of the light guide plate 10 widens.
  • the angle of the lenticular 23 increases, the angle of the curved surface of the lenticular 23 with respect to incident light on the upper surface 21 of the light guide plate 10 increases, so the incident angle easily exceeds the critical angle.
  • the width W2 of the light beam emitted from the upper surface 21 of the light guide plate 10 narrows.
  • the luminance distribution of the light emitted from the upper surface 21 of the light guide plate 10 can be easily controlled.
  • FIGS. 5A to 5C show the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10.
  • the angle of the lenticulars 23 of the light guide plate 10 shown in FIG. 5A is smaller than the angle of the lenticulars 23 of the light guide plate 10 shown in FIG. 5B.
  • FIGS. 5A and 5B light emitted from one light source 11 is incident on the light guide plate 10.
  • emitted from the upper surface 21 of the light-guide plate 10 has spread in the width direction (X direction of FIG. 5A) of the light-guide plate 10.
  • FIG. The lateral width direction of the light guide plate 10 is a direction orthogonal to the optical axis of the light source 11.
  • FIG. 5C shows the spread of the luminance of the light emitted from the upper surface 21 of the light guide plate 10.
  • the vertical axis in FIG. 5C is the brightness of light emitted from the upper surface 21 of the light guide plate 10
  • the horizontal axis in FIG. 5C is the horizontal width (mm) of the light guide plate 10.
  • 5C is the brightness of the light emitted from the upper surface 21 of the light guide plate 10 at the alternate long and short dash line AA in FIG. 5A.
  • the solid line D in FIG. 5C is the brightness of light emitted from the upper surface 21 of the light guide plate 10 at the alternate long and short dash line BB in FIG. 5B.
  • FIG. 6 is a view showing the relationship between the brightness of light emitted from the upper surface 21 of the light guide plate 10 and the angle of the lenticular 23.
  • the vertical axis in FIG. 6 is the full width half maximum of the luminance of light emitted from the upper surface 21 of the light guide plate 10, and the horizontal axis in FIG. 6 is the angle of the lenticular 23.
  • the full width at half maximum of the luminance of light emitted from the upper surface 21 of the light guide plate 10 is, as shown in FIG. 7, the width at half the peak value of the luminance of light emitted from the upper surface 21 of the light guide plate 10 (W3) It is.
  • the full width at half maximum in the case where the angle of the lenticular 23 is 15 degrees is plotted as 1.0.
  • the full width at half maximum when the angle of the lenticular 23 in FIG. 6 is 30, 45, 60, and 75 degrees is a ratio to the full width at half maximum when the angle of the lenticular 23 is 15 degrees.
  • the full width at half maximum when the angle of the lenticular 23 is 35 degrees or more and 75 degrees or less is not more than half the full width at half maximum when the angle of the lenticular 23 is 15 degrees.
  • FIG. 8 is a diagram showing the relationship between the contrast ratio and the angle of the lenticular 23.
  • the vertical axis in FIG. 8 is the contrast ratio
  • the horizontal axis in FIG. 8 is the angle of the lenticular 23.
  • FIG. 8 shows the contrast ratio when the thickness of the light guide plate 10 is 0.4 mm.
  • the thickness of the light guide plate 10 excludes the height of the lenticular 23. That is, the thickness of the light guide plate 10 excluding the portion of the lenticular 23 is 0.4 mm.
  • the contrast ratio is the peak of the luminance of the light emitted from the upper surface 21 of the light guide plate 10 at the low luminance part (low luminance part, point A in FIG.
  • the contrast ratio is 1/5000 or less when the angle of the lenticular 23 is in the range of 30 degrees to 70 degrees, and the contrast ratio is in the range of 45 degrees to 60 degrees of the lenticular 23 It is a value around 1/10000. As shown in FIG. 8, in the range of the angle of the lenticular 23 in the range of 30 degrees to 70 degrees, the contrast ratio is improved by three times or more as compared with the case where the angle of the lenticular 23 is 15 degrees.
  • FIG. 10 the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10 when the angle of the lenticular 23 is 45 degrees and the upper surface 21 of the light guide plate 10 when the angle of the lenticular 23 is 75 degrees
  • the luminance distribution of the emitted light is shown.
  • the vertical axis in FIG. 10 is the brightness of light emitted from the upper surface 21 of the light guide plate 10
  • the horizontal axis in FIG. 10 is the distance from the optical axis of the light source 11.
  • the distance from the optical axis of the light source 11 increases, the light intensity in the case where the angle of the lenticular 23 is 75 degrees than the light intensity in the case where the angle of the lenticular 23 is 45 degrees.
  • the brightness is increased.
  • the contrast ratio when the angle of the lenticular 23 is 75 degrees is larger than the contrast ratio when the angle of the lenticular 23 is 45 degrees. As shown in FIG. 8, when the angle of the lenticular 23 becomes larger than 70 degrees, the contrast ratio becomes larger than 1/5000.
  • FIG. 11 is a view showing the relationship between the thickness of the light guide plate 10, the contrast ratio, and the angle of the lenticular 23.
  • the vertical axis in FIG. 11 is the contrast ratio
  • the horizontal axis in FIG. 11 is the angle of the lenticular 23.
  • FIG. 11 shows the contrast ratios when the thickness of the light guide plate 10 is 0.2 mm, 0.3 mm, 0.5 mm, and 1.0 mm.
  • the thickness of the light guide plate 10 excludes the height of the lenticular 23. That is, the thickness of the light guide plate 10 excluding the portion of the lenticular 23 is 0.2 mm, 0.3 mm, 0.5 mm, and 1.0 mm.
  • the contrast ratio is shown in logarithm.
  • the contrast ratio is improved as compared with the case where the angle of the lenticular 23 is 15 degrees.
  • the thickness of the light guide plate 10 is 0.2 mm or more and 1.0 mm or less, by setting the angle of the lenticular 23 to 30 degrees or more and 75 degrees or less, comparison with the case where the angle of the lenticular 23 is 15 degrees to improve the contrast ratio.
  • Moire on the screen of the liquid crystal display device is less likely to occur when the pitch of the lenticular 23 is narrow.
  • moire on the screen of the liquid crystal display device is less likely to be recognized when the moire pitch is narrow.
  • the thickness of the light guide plate 10 is 1.0 mm
  • the angle of the lenticular 23 is 65 degrees
  • the height of the lenticular 23 is 0.012 mm
  • the pitch of the lenticular 23 is 0.042 mm
  • the curvature radius ratio is 0.012.
  • the moiré pitch is 1 mm or less.
  • the plurality of light sources 11 may be disposed on the light incident surface 20 side of the light guide plate 10, and the plurality of light sources 41 may be disposed on the light incident surface 24 side of the light guide plate 10.
  • the light incident surface 24 of the light guide plate 10 is the surface opposite to the light incident surface 20 of the light guide plate 10.
  • the configuration of the light source 41 is the same as the configuration of the light source 11.
  • the light incident surface 20 is an example of a first light incident surface.
  • the light incident surface 24 is an example of a second light incident surface.
  • the light source 11 is an example of a first light source.
  • the light source 41 is an example of a second light source.
  • the light source 11 is disposed at a position facing the light incident surface 20 of the light guide plate 10, and the light source 41 is disposed at a position facing the light incident surface 24 of the light guide plate 10.
  • the light emitted from the light source 11 enters the inside of the light guide plate 10 from the light incident surface 20 of the light guide plate 10, and the light emitted from the light source 41 enters the light guide plate 10 from the light incident surface 24 of the light guide plate 10. enter.
  • FIGS. 12A and 12B The luminance distribution of the light emitted from the upper surface 21 of the light guide plate 10 is shown in FIGS. 12A and 12B.
  • FIG. 12A light emitted from one light source 11 is incident on the light guide plate 10.
  • FIG. 12B light emitted from one light source 11 and one light source 41 is incident on the light guide plate 10.
  • FIG. 12B the light guide distance in the light guide plate 10 is shortened by entering the light from the light entrance surface 20 and the light entrance surface 24 of the light guide plate 10. Therefore, as shown to FIG. 12B, it is suppressed that the brightness
  • a plurality of lenticulars 23 are continuously arranged, and an example in which two adjacent lenticulars 23 are connected is shown. It is not limited to the example of composition of light guide plate 10 shown in Drawing 3A and Drawing 3B, but a plurality of lenticulars 23 may be arranged at fixed intervals.
  • a flat portion (flat surface) 25 may be provided between adjacent ones of the plurality of lenticulars 23.
  • a plurality of lenticulars 23 are arranged in parallel with each other at a constant interval.
  • the upper surface 21 of the light guide plate 10 is formed by the curved surfaces 23A of the plurality of lenticulars 23 and the plurality of flat portions 25.
  • the flat portion (flat surface) 25 is the same surface as the flat surface 31 of the flat plate portion 30. Therefore, in the configuration example of the light guide plate 10 shown in FIG. 13A, the upper surface 21 of the light guide plate 10 is formed by the curved surfaces 23A of the plurality of lenticulars 23 and the flat surfaces 31 of the flat plate portion 30.
  • the flat portion 25 may be parallel to the lower surface 22 of the light guide plate 10.
  • the angle of the lenticular 23 shown in FIG. 13A is, for example, 80 degrees.
  • the contrast ratio is 1 even if the angle of the lenticulars 23 is larger than 70 degrees. It can be smaller than / 5000.
  • the angle of the lenticular 23 shown in FIG. 13A may be other than 80 degrees, and may be, for example, 30 degrees or more and 70 degrees or less, or 45 degrees or more and 60 degrees or less.
  • FIG. 13B the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10 without the flat portion 25 and the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10 with the flat portion 25 provided. And are shown.
  • the plurality of lenticulars 23 are disposed on the flat surface 31 of the flat plate portion 30 without a gap.
  • the vertical axis in FIG. 13B is the brightness of light emitted from the upper surface 21 of the light guide plate 10, and the horizontal axis in FIG.
  • the angle of the lenticular 23 in the light guide plate 10 in which the flat portion 25 is not provided is 60 degrees, and the angle of the lenticular 23 in the light guide plate 10 in which the flat portion 25 is provided is 80 degrees.
  • the thickness of the light guide plate 10 excluding the portion of the lenticular 23 is 0.4 mm.
  • the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10 where the flat portion 25 is not provided and the light distribution of the light emitted from the upper surface 21 of the light guide plate 10 where the flat portion 25 is provided It is equal to the luminance distribution.
  • FIG. 13C shows the contrast ratio in the light guide plate 10 in which the flat portion 25 is not provided and the contrast ratio in the light guide plate 10 in which the flat portion 25 is provided.
  • the thickness of the light guide plate 10 excluding the portion of the lenticular 23 is 0.4 mm.
  • the portion of the lenticular 23 is The same effect as in the case where the thickness of the removed light guide plate 10 is 0.4 mm can be obtained.
  • the light guide plate 10 provided with the flat portion 25 can obtain the same effect as the light guide plate 10 in which the flat portion 25 is not provided, in the range where the angle of the lenticular 23 is 30 degrees or more and 70 degrees or less.
  • the contrast ratio is 1/5000 or less and the angle of the lenticular 23 is 45 degrees or more 60 in the range of 30 degrees or more and 80 degrees or less.
  • the contrast ratio becomes a value near 1/10000 in the range below degree.
  • the angle of the lenticular 23 may be adjusted by changing the height and the radius of curvature of the lenticular 23.
  • the angle of the lenticular 23 may be adjusted by changing the radius of curvature of the lenticular 23 while keeping the height of the lenticular 23 constant.
  • the angle of the lenticular 23 may be adjusted by changing the height of the lenticular 23 while keeping the curvature radius of the lenticular 23 constant.
  • the plurality of lenticulars 23 are provided on the flat surface 31 of the flat plate portion 30, and each lenticular 23 is guided as viewed from the normal direction of the flat surface 31 of the flat plate portion 30.
  • An example is shown in which the ridges extend in the direction perpendicular to the light incident surface 20 of the light plate 10.
  • a plurality of lenticulars 33 are provided in plane 32 of flat plate part 30, and each lenticular 33 is It may be a ridge extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 as viewed in the normal direction of the plane 32.
  • the flat surface 32 of the flat plate portion 30 is a surface opposite to the flat surface 31 of the flat plate portion 30.
  • the plurality of lenticulars 33 have curved surfaces 33A.
  • the curved surface 33A is inclined with respect to the plane 32. Therefore, the lenticular 33 has an inclined surface which is inclined with respect to the plane 32.
  • the upper surface 21 of the light guide plate 10 is formed by the flat surface of the flat plate portion 30, and light is emitted from the upper surface 21 of the light guide plate 10.
  • the lower surface 22 of the light guide plate 10 is formed by the curved surfaces 33A of the plurality of lenticulars 33.
  • the angle of the lenticular 33 is an angle ( ⁇ ) formed by the flat surface 32 of the flat plate portion 30 and the tangent L2 of the curved surface 33A at the end of the lenticular 33 (see FIG. 14B).
  • the lenticular 33 is provided on the lower surface 22 side of the light guide plate 10, the brightness of light emitted from the upper surface 21 of the light guide plate 10 is the same as when the lenticular 23 is provided on the upper surface 21 side of the light guide plate 10. It is possible to suppress the spread of Further, the lenticular 23 may be provided on the upper surface 21 side of the light guide plate 10 and the lenticular 33 may be provided on the lower surface 22 side of the light guide plate 10. In addition, a plurality of lenticulars 33 may be disposed on the flat surface 32 of the flat plate portion 30 with a predetermined interval.
  • the lenticular 23 is a convex stripe provided on the plane 31 of the flat plate portion 30 .
  • the present invention is not limited to the configuration example of the light guide plate 10 shown in FIGS. 3A and 3B, but as shown in FIGS. 15 and 16A, a plurality of lenticulars 23 are provided on the flat surface 31 of the flat plate portion 30, and each lenticular 23 is flat It may be a concave extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 as viewed in the normal direction of the plane 31 of the portion 30.
  • the plurality of lenticulars 23 have curved surfaces 23B.
  • the curved surface 23 B is inclined with respect to the plane 31. Therefore, the lenticular 23 has an inclined surface which is inclined with respect to the plane 31.
  • the upper surface 21 of the light guide plate 10 is formed by the curved surfaces 23B of the plurality of lenticulars 23.
  • the curved surface 23 B of the lenticular 23 is recessed from the flat surface 31 of the flat plate portion 30 in the normal direction of the flat surface 31 of the flat plate portion 30.
  • the distribution of light emitted from the upper surface 21 of the light guide plate 10 can be controlled, and the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10 can be controlled.
  • the plurality of lenticulars 23 are arranged parallel to one another. In the configuration example of the light guide plate 10 shown in FIG. 15, FIG. 16A and FIG. 16B, a plurality of lenticulars 23 are continuously arranged, and two adjacent lenticulars 23 are connected. Therefore, in the configuration example of the light guide plate 10 shown in FIG. 15, FIG. 16A and FIG. 16B, the plurality of lenticulars 23 are disposed on the flat surface 31 of the flat plate portion 30 without a gap.
  • the width of the lenticular 23 and the pitch of the lenticular 23 are the same.
  • the angle of the lenticular 23 is an angle ( ⁇ ) formed by the flat surface 31 of the flat plate portion 30 and the tangent L3 of the curved surface 23B at the end of the lenticular 23 (see FIG. 16B).
  • the contrast ratio can be set to a value near 1/10000 in the range where the angle of the lenticulars 23 is 45 degrees or more and 60 degrees or less.
  • the angle of the lenticular 23 is 30 degrees or more and 75 degrees or less By doing this, it is possible to improve the contrast ratio.
  • composition of light guide plate 10 shown in Drawing 15, Drawing 16A, and Drawing 16B and a plurality of lenticulars 23 may be arranged at fixed intervals.
  • flat portions 25 may be provided between adjacent ones of the plurality of lenticulars 23.
  • a plurality of lenticulars 23 are arranged in parallel with each other at a constant interval.
  • the upper surface 21 of the light guide plate 10 is formed by the curved surfaces 23 B of the plurality of lenticulars 23 and the plurality of flat portions 25.
  • the flat portion (flat surface) 25 is the same surface as the flat surface 31 of the flat plate portion 30. Therefore, in the configuration example of the light guide plate 10 shown in FIG. 17, the upper surface 21 of the light guide plate 10 is formed by the curved surfaces 23 B of the plurality of lenticulars 23 and the flat surfaces 31 of the flat plate portion 30. The flat portion 25 may be parallel to the lower surface 22 of the light guide plate 10.
  • the angle of the lenticular 23 shown in FIG. 17 is, for example, 80 degrees.
  • the angle of the lenticular 23 shown in FIG. 17 may be other than 80 degrees, and may be, for example, 30 degrees or more and 70 degrees or less, or 45 degrees or more and 60 degrees or less.
  • a plurality of lenticulars 23 are provided on the flat surface 31 of the flat plate portion 30, and a part of the plurality of lenticulars 23 is a convex stripe, and another one of the plurality of lenticulars 23 is The part may be concave.
  • a plurality of ridges are arranged to be adjacent to each other, and a plurality of grooves are arranged to be adjacent to each other.
  • the plurality of lenticulars 23 are disposed on the flat surface 31 of the flat plate portion 30 without a gap.
  • the plurality of convex lines and the plurality of concave lines are disposed on the flat surface 31 of the flat plate portion 30 without a gap.
  • the present invention is not limited to the configuration example of the light guide plate 10 shown in FIG. 18.
  • one or more convex lines and one or more concave lines may be alternately disposed on the flat surface 31 of the flat plate portion 30. Similar to the configuration example of the light guide plate 10 shown in FIGS. 13A and 17, by providing the flat portion 25 between the adjacent ones of the plurality of lenticulars 23, the plurality of convex stripes and the plurality of concave stripes are constant.
  • a plurality of ridges may be disposed on the flat surface 31 of the flat plate portion 30 at a constant interval, and a plurality of concave stripes may be disposed on the flat surface 31 of the flat plate portion 30 without a gap.
  • a plurality of ridges may be disposed on the flat surface 31 of the flat plate portion 30 without a gap, and a plurality of concave stripes may be disposed on the flat surface 31 of the flat plate portion 30 at a constant interval.
  • a plurality of convex lines and a plurality of concave lines may be disposed on the flat surface 32 of the flat plate portion 30 at a constant interval.
  • a plurality of ridges may be disposed on the flat surface 32 of the flat plate portion 30 at a constant interval, and a plurality of concave stripes may be disposed on the flat surface 32 of the flat plate portion 30 without a gap.
  • a plurality of ridges may be disposed on the flat surface 32 of the flat plate portion 30 without a gap, and a plurality of concave stripes may be disposed on the flat surface 32 of the flat plate portion 30 at regular intervals.
  • the spread of the luminance of light emitted from the upper surface 21 of the light guide plate 10 can be suppressed by setting the angle of the lenticular 23 to 30 degrees or more and 70 degrees or less. Therefore, the contrast ratio is improved. Since the spread of the luminance of the light emitted from the upper surface 21 of the light guide plate 10 can be suppressed, the control of the light emission luminance in the narrow width area becomes easy in the local dimming control. Further, according to the light guide plate 10 of the embodiment, the contrast ratio is further improved by setting the angle of the lenticular 23 to 45 degrees or more and 60 degrees or less. Therefore, by mounting the surface light source device 1 including such a light guide plate 10 as a backlight, it is possible to provide a liquid crystal display device having an improved contrast ratio.
  • the light guide plate 10 includes a plurality of lenticulars 23 provided on the flat surface 31 of the flat plate portion 30, and each lenticular 23 has a curved surface 23A and a flat surface 51A.
  • Each lenticular 23 is a ridge extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 when viewed in the normal direction of the flat surface 31 of the flat plate portion 30.
  • the curved surface 23A and the flat surface 51A are inclined with respect to the plane 31. Therefore, the lenticular 23 has an inclined surface which is inclined with respect to the plane 31.
  • a plurality of lenticulars 23 are continuously arranged, and adjacent ones of the lenticulars 23 are connected. Two facing flat surfaces 51A of two adjacent lenticulars 23 are connected to each other. Therefore, the plurality of lenticulars 23 are disposed on the flat surface 31 of the flat plate portion 30 without a gap.
  • the flat portion 25 is provided between the adjacent lenticulars 23. The flat portions 25 are connected to the flat surfaces 51A of the adjacent lenticulars 23. Therefore, a plurality of lenticulars 23 are arranged in parallel with each other at a constant interval.
  • 19C to 19E are views showing the light guide plate 10 according to the embodiment.
  • the angle of the lenticular 23 is 60 degrees, but the angle of the lenticular 23 may be other than 60 degrees.
  • the angle of the lenticular 23 may be, for example, 30 degrees or more and 80 degrees or less, 30 degrees or more and 70 degrees or less, or 45 degrees or more and 60 degrees or less.
  • the angle of the lenticular 23 is an angle ( ⁇ ) formed by the flat surface 31 of the flat plate portion 30 and the flat surface 51 A at the end of the lenticular 23.
  • the lenticular 23 when viewed from the normal direction of the light incident surface 20 of the light guide plate 10, the lenticular 23 has a trapezoidal portion 52A and an arc-shaped portion 53A contacting the upper bottom of the trapezoidal portion 52A. including.
  • the length of the upper base of the trapezoidal portion 52A is shorter than the length of the lower base of the trapezoidal portion 52A.
  • the trapezoidal portion 52A is in contact with the flat surface 31 of the flat plate portion 30, and the arc-shaped portion 53A is separated from the flat surface 31 of the flat plate portion 30.
  • the height of the trapezoidal portion 52A is 50% of the total value of the height of the trapezoidal portion 52A and the height of the arc-shaped portion 53A.
  • the height of the trapezoidal portion 52A is 80% of the total value of the height of the trapezoidal portion 52A and the height of the arc-shaped portion 53A.
  • the height of the trapezoidal portion 52A is 90% of the total value of the height of the trapezoidal portion 52A and the height of the arc-shaped portion 53A.
  • the ratio of the height of the trapezoidal portion 52A to the sum of the height of the trapezoidal portion 52A and the height of the arc-shaped portion 53A is not limited to 50%, 80% and 90%.
  • the ratio of the height of the trapezoidal portion 52A to the total value of the height of the trapezoidal portion 52A and the height of the arc-shaped portion 53A may be 0% or more and 100% or less.
  • FIG. 20A shows the luminance distribution of the light emitted from the upper surface 21 of the light guide plate 10 when the angle of the lenticular 23 is 60 degrees.
  • the vertical axis in FIG. 20A is the brightness of light emitted from the upper surface 21 of the light guide plate 10
  • the horizontal axis in FIG. 20A is the distance from the optical axis of the light source 11.
  • the ratio of the height of trapezoidal portion 52A to the total value of the height of trapezoidal portion 52A and the height of arc-shaped portion 53A is 0%, 50%, 80% and 90%.
  • the luminance distribution of the light is shown.
  • the lenticular 23 has the circular arc portion 53A, but the trapezoidal portion It does not have 52A. Therefore, when the ratio of the height of the trapezoidal portion 52A to the total value of the height of the trapezoidal portion 52A and the height of the arc-shaped portion 53A is 0%, the lenticular 23 has a curved surface 23A, but the flat surface 51A. Do not have
  • the same effect as the case where the lenticular 23 has only the curved surface 23A can be obtained. it can.
  • FIG. 20B shows the contrast ratio when the angle of the lenticular 23 is 60 degrees.
  • the ratio of the height of trapezoidal portion 52A to the total value of the height of trapezoidal portion 52A and the height of arc-shaped portion 53A is 0%, 50%, 80% and 90%.
  • the contrast ratio is shown.
  • the contrast ratio can be improved by setting the angle of the lenticular 23 to 30 degrees or more and 80 degrees or less, and by the lenticular 23 having the curved surface 23A and the flat surface 51A.
  • the light guide plate 10 includes a plurality of lenticulars 23 provided on the flat surface 31 of the flat plate portion 30, and each lenticular 23 has a curved surface 23B and a flat surface 51B.
  • Each lenticular 23 is a concave extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 as viewed in the normal direction of the flat surface 31 of the flat plate portion 30.
  • the curved surface 23 B and the flat surface 51 B are inclined with respect to the plane 31. Therefore, the lenticular 23 has an inclined surface which is inclined with respect to the plane 31.
  • a plurality of lenticulars 23 are continuously arranged, and adjacent ones of the lenticulars 23 are connected. Two flat surfaces 51B of two adjacent lenticulars 23 are connected to each other. Therefore, the plurality of lenticulars 23 are disposed on the flat surface 31 of the flat plate portion 30 without a gap.
  • the flat portion 25 is provided between the adjacent lenticulars 23. The flat portions 25 are connected to the flat surfaces 51B of the adjacent lenticulars 23. Therefore, a plurality of lenticulars 23 are arranged in parallel with each other at a constant interval.
  • FIG. 21C is a view showing the light guide plate 10 according to the embodiment.
  • the angle of the lenticular 23 is 60 degrees, but the angle of the lenticular 23 may be other than 60 degrees.
  • the angle of the lenticular 23 may be, for example, 30 degrees or more and 80 degrees or less, 30 degrees or more and 70 degrees or less, or 45 degrees or more and 60 degrees or less.
  • the angle of the lenticular 23 is an angle ( ⁇ ) formed by the flat surface 31 of the flat plate portion 30 and the flat surface 51 B at the end of the lenticular 23.
  • the contrast ratio can be improved by setting the angle of the lenticular 23 to not less than 30 degrees and not more than 80 degrees and having the curved surface 23B and the flat surface 51B.
  • the lenticular 23 includes a trapezoidal portion 52B and an arc-shaped portion 53B in contact with the lower bottom of the trapezoidal portion 52B when viewed in the normal direction of the light incident surface 20 of the light guide plate 10.
  • the length of the lower base of the trapezoidal portion 52B is shorter than the length of the upper base of the trapezoidal portion 52B.
  • the trapezoidal portion 52B is in contact with the flat surface 31 of the flat plate portion 30, and the arc-shaped portion 53B is separated from the flat surface 31 of the flat plate portion 30.
  • the height of the trapezoidal portion 52B is 50% of the total value of the height of the trapezoidal portion 52B and the height of the arc-shaped portion 53B.
  • the ratio of the height of the trapezoidal portion 52B to the sum of the height of the trapezoidal portion 52B and the height of the arc-shaped portion 53B is not limited to 50%.
  • the ratio of the height of the trapezoidal portion 52B to the total value of the height of the trapezoidal portion 52B and the height of the arc-shaped portion 53B may be 0% or more and 100% or less.
  • Drawing 22A and Drawing 22B are figures showing light guide plate 10 concerning an embodiment.
  • the light guide plate 10 includes a plurality of lenticulars 33 provided on the flat surface 32 of the flat plate portion 30, and each lenticular 33 has a curved surface 33A and a flat surface 61A.
  • Each of the lenticulars 33 is a ridge extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 when viewed in the normal direction of the flat surface 32 of the flat plate portion 30.
  • the curved surface 33A and the flat surface 61A are inclined with respect to the plane 32. Therefore, the lenticule 33 has an inclined surface which is inclined with respect to the plane 32.
  • a plurality of lenticulars 33 are continuously arranged, and adjacent ones of the lenticulars 33 are connected. Two facing flat surfaces 61A of two adjacent lenticulars 33 are connected to each other. Therefore, the plurality of lenticulars 33 are disposed on the flat surface 32 of the flat plate portion 30 without any gap.
  • the flat portion 25 is provided between the adjacent lenticulars 33. The flat portion 25 is connected to each flat surface 61A of the adjacent lenticule 33. Therefore, the plurality of lenticulars 33 are arranged in parallel with each other at a constant interval.
  • Drawing 22C is a figure showing light guide plate 10 concerning an embodiment.
  • the angle of the lenticular 33 is 60 degrees, but the angle of the lenticular 33 may be other than 60 degrees.
  • the angle of the lenticular 33 may be, for example, 30 degrees or more and 80 degrees or less, 30 degrees or more and 70 degrees or less, or 45 degrees or more and 60 degrees or less.
  • the angle of the lenticular 33 is an angle ( ⁇ ) formed by the flat surface 32 of the flat plate portion 30 and the flat surface 61A at the end of the lenticular 33.
  • the contrast ratio can be improved by the lenticular 33 having an angle of 30 degrees or more and 80 degrees or less, and the lenticulars 33 having the curved surface 33A and the flat surface 61A.
  • the lenticular 33 includes a trapezoidal portion 62A and an arc-shaped portion 63A in contact with the lower bottom of the trapezoidal portion 62A when viewed in the normal direction of the light incident surface 20 of the light guide plate 10.
  • the length of the lower base of the trapezoidal portion 62A is shorter than the length of the upper base of the trapezoidal portion 62A.
  • the trapezoidal portion 62A is in contact with the flat surface 32 of the flat plate portion 30, and the arc-shaped portion 63A is separated from the flat surface 32 of the flat plate portion 30.
  • the height of the trapezoidal portion 62A is 50% of the total value of the height of the trapezoidal portion 62A and the height of the arc-shaped portion 63A.
  • the ratio of the height of the trapezoidal portion 62A to the sum of the height of the trapezoidal portion 62A and the height of the arc-shaped portion 63A is not limited to 50%.
  • the ratio of the height of the trapezoidal portion 62A to the total value of the height of the trapezoidal portion 62A and the height of the arc-shaped portion 63A may be 0% or more and 100% or less.
  • the light guide plate 10 includes a plurality of lenticulars 33 provided on the flat surface 32 of the flat plate portion 30, and each lenticular 33 has a curved surface 33B and a flat surface 61B.
  • Each of the lenticulars 33 is a concave extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 as viewed in the normal direction of the flat surface 32 of the flat plate portion 30.
  • the curved surface 33 B and the flat surface 61 B are inclined with respect to the plane 32. Therefore, the lenticule 33 has an inclined surface which is inclined with respect to the plane 32.
  • a plurality of lenticulars 33 are continuously arranged, and adjacent ones of the lenticulars 33 are connected. Two opposing flat surfaces 61B of two adjacent lenticulars 33 are connected to each other. Therefore, the plurality of lenticulars 33 are disposed on the flat surface 32 of the flat plate portion 30 without any gap.
  • the flat portion 25 is provided between the adjacent lenticulars 33. The flat portions 25 are connected to the flat surfaces 61 B of the adjacent lenticulars 33. Therefore, the plurality of lenticulars 33 are arranged in parallel with each other at a constant interval.
  • FIG. 23C is a view showing the light guide plate 10 according to the embodiment.
  • the angle of the lenticular 33 is 60 degrees, but the angle of the lenticular 33 may be other than 60 degrees.
  • the angle of the lenticular 33 may be, for example, 30 degrees or more and 80 degrees or less, 30 degrees or more and 70 degrees or less, or 45 degrees or more and 60 degrees or less.
  • the angle of the lenticular 33 is an angle ( ⁇ ) formed by the flat surface 32 of the flat plate portion 30 and the flat surface 61 B at the end of the lenticular 33.
  • the contrast ratio can be improved by the lenticular 33 having an angle of 30 degrees or more and 80 degrees or less and the lenticulars 33 having the curved surface 33B and the flat surface 61B.
  • the lenticule 33 includes a trapezoidal portion 62B and an arc-shaped portion 63B in contact with the upper bottom of the trapezoidal portion 62B when viewed in the normal direction of the light incident surface 20 of the light guide plate 10.
  • the length of the upper base of the trapezoidal portion 62B is shorter than the length of the lower base of the trapezoidal portion 62B.
  • the trapezoidal portion 62B is in contact with the flat surface 32 of the flat plate portion 30, and the arc-shaped portion 63B is separated from the flat surface 32 of the flat plate portion 30.
  • the height of the trapezoidal portion 62B is 50% of the total value of the height of the trapezoidal portion 62B and the height of the arc-shaped portion 63B.
  • the ratio of the height of the trapezoidal portion 62B to the sum of the height of the trapezoidal portion 62B and the height of the arc-shaped portion 63B is not limited to 50%.
  • the ratio of the height of the trapezoidal portion 62B to the total value of the height of the trapezoidal portion 62B and the height of the arc-shaped portion 63B may be 0% or more and 100% or less.
  • switching of the liquid crystal is performed by setting a part of the plurality of light sources 11 and 41 to a non-lighting state and partially changing the inside of the screen to a scan of the liquid crystal. It is possible to reduce an afterimage in a moving image by preventing the visual recognition of the A technique for reducing such residual images in moving images is called backlight scanning.
  • the liquid crystal display device according to the embodiment since the spread of the luminance of the light emitted from the upper surface 21 of the light guide plate 10 can be suppressed, the display control of the partial black region in the screen can be improved. it can. Also, such a liquid crystal display device can be used also when displaying content using VR (Virtual Reality) technology.
  • VR Virtual Reality
  • liquid crystal display device can be mounted on various electronic devices.
  • a smartphone, a digital camera, a tablet terminal, an electronic book, a wearable device, a car navigation device, an electronic dictionary, an electronic advertisement board, etc. can be illustrated as an electronic device provided with such a liquid crystal display device.
  • Reference Signs List 1 surface light source device 2 display panel 10 light guide plate 11, 41 light source 12 FPC 13 fixing member 14 frame 15 reflection sheet 16 diffusion sheet 17 prism sheet 18 light shielding double-sided tape 23, 33 lenticular 23A, 23B, 33A, 33B curved surface 30 flat plate portion 31, 32 plane 51A, 51B, 61A, 61B flat surface

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Planar Illumination Modules (AREA)

Abstract

The purpose of the present invention is to suppress the spread of brightness of light emitted from a light exit surface of a light guide plate. Provided is an approximately flat plate-shaped light guide plate which has a light entry surface to the side thereof for the entry of light, and which outputs, via the light exit surface, the light entered via the light entry surface. The light guide plate is provided with a flat plate portion and a plurality of ridge lines and/or a plurality of recessed lines which are provided on a planar surface of the flat plate portion and which, as viewed from a direction normal to the planar surface, extend in a direction perpendicular to the light entry surface. The plurality of ridge lines and recessed lines include inclined surfaces inclined with respect to the planar surface. The light exit surface is formed of the inclined surfaces of the plurality of ridge lines and/or the plurality of recessed lines. An angle formed by the planar surface and a tangent to the inclined surfaces at the end of the ridge lines and/or the recessed lines is not less than 30 degrees and not more than 70 degrees.

Description

導光板、面光源装置、表示装置及び電子機器Light guide plate, surface light source device, display device and electronic device
　本発明は、導光板、面光源装置、表示装置及び電子機器に関する。 The present invention relates to a light guide plate, a surface light source device, a display device and an electronic device.
　近年、電子機器の小型化、薄型化が進んでいる。このような電子機器に搭載される液晶表示装置には、同一の面積でより大きな表示領域を得るための狭額縁化や、薄型化のニーズがある。表示パネルのバックライトには、例えば、白色光を出射するＬＥＤ（Light Emitting Diode）を光源とし、導光板（ライトガイドとも呼ばれる）を用いたサイドライトタイプ（エッジライト方式とも呼ばれる）の面光源装置が用いられている。液晶表示装置では、画面を複数の領域（点灯エリア）に分割し、複数の領域毎に発光輝度を制御することが行われている。このような制御は、ローカルディミング制御と呼ばれる。ローカルディミングの適用が可能なエッジライト方式の面光源装置が提案されている（特許文献１参照）。ローカルディミングの効率が向上可能な導光板及びエッジライト型バックライトが提案されている（特許文献２参照）。 BACKGROUND In recent years, miniaturization and thinning of electronic devices have progressed. In liquid crystal display devices mounted in such electronic devices, there is a need for narrowing of the frame for obtaining a larger display area with the same area, and thinning. Sidelight type (also referred to as edge light type) surface light source device using a light guide plate (also referred to as a light guide) with an LED (Light Emitting Diode) emitting white light as a light source, for example, as a backlight of a display panel Is used. In the liquid crystal display device, the screen is divided into a plurality of areas (lighting areas), and the light emission luminance is controlled for each of the plurality of areas. Such control is called local dimming control. There has been proposed an edge light type surface light source device to which local dimming can be applied (see Patent Document 1). A light guide plate and an edge light type backlight capable of improving the efficiency of local dimming have been proposed (see Patent Document 2).
特開２０１３－０６９６６８号公報JP, 2013-069668, A 特開２０１３－１２７９６６号公報JP, 2013-127966, A
　光源から出射された光は、導光板に入射され、導光板の内部で反射を繰り返しながら導光板の内部を進む。導光板の出光面に入射する光が、臨界角よりも小さな入射角で入射すると、導光板の出光面から外部に光が出射される。導光板の出光面から出射される光の輝度の広がりが大きい場合、ローカルディミング制御において、狭い幅の領域における発光輝度の制御が困難になる。 The light emitted from the light source is incident on the light guide plate and travels the inside of the light guide plate while being repeatedly reflected inside the light guide plate. When light incident on the light exit surface of the light guide plate is incident at an incident angle smaller than the critical angle, light is emitted from the light exit surface of the light guide plate to the outside. When the spread of the luminance of the light emitted from the light exit surface of the light guide plate is large, it is difficult to control the light emission luminance in the narrow width region in the local dimming control.
　このような状況に鑑み、本発明は、導光板の出光面から出射される光の輝度の広がりを抑制することを目的とする。 In view of such a situation, an object of the present invention is to suppress the spread of the luminance of light emitted from the light exit surface of the light guide plate.
　本発明では、上記課題を解決するために、以下の手段を採用した。すなわち、本発明は、光が入射する入光面を側方に有し、入光面から入射する光を出光面から出射する概略平板状の導光板であって、平板部と、平板部の平面に設けられ、平面の法線方向から見て、入光面に対して垂直方向に延在する複数の凸条及び凹条の少なくとも一方と、を備え、複数の凸条及び凹条の少なくとも一方は平面に対して傾斜する傾斜面を有し、出光面は、複数の凸条及び凹条の少なくとも一方の傾斜面によって形成され、平面と凸条及び凹条の少なくとも一方の端部における傾斜面の接線とでなす角度が３０度以上７０度以下である、導光板である。 The present invention adopts the following means in order to solve the above problems. That is, the present invention is a substantially flat light guide plate having a light incident surface to which light is incident on the side and emitting light incident from the light incident surface from the light emitting surface, and it has a flat portion and a flat portion. And at least one of a plurality of ridges and grooves extending in a direction perpendicular to the light entrance surface, provided in a plane and viewed in a direction normal to the plane, at least one of the plurality of ridges and grooves One has an inclined surface inclined with respect to the plane, and the light emitting surface is formed by the inclined surface of at least one of the plurality of ridges and grooves, and the inclination at the end of the plane and at least one of the ridges and grooves It is a light guide plate which makes an angle of 30 degrees or more and 70 degrees or less with the tangent of a field.
　本発明に係る導光板によれば、導光板が備える平板部の平面と凸条及び凹条の少なくとも一方の端部における傾斜面の接線とでなす角度を３０度以上７０度以下とすることにより、導光板の出光面から出射される光の輝度の広がりを抑制することができる。 According to the light guide plate of the present invention, the angle formed by the plane of the flat plate portion of the light guide plate and the tangent of the inclined surface at the end of at least one of the ridges and grooves is 30 degrees or more and 70 degrees or less. The spread of the luminance of the light emitted from the light exit surface of the light guide plate can be suppressed.
　本発明に係る導光板において、平板部の平面と凸条及び凹条の少なくとも一方の端部における傾斜面の接線とでなす角度が４５度以上６０度以下であってもよい。本発明に係る導光板において、傾斜面は、曲面を含んでもよい。本発明に係る導光板において、傾斜面は、曲面及び平坦面を含み、平面と凸条及び凹条の少なくとも一方の端部における平坦面とでなす角度が３０度以上７０度以下であってもよい。本発明に係る導光板において、傾斜面は、曲面及び平坦面を含み、平面と凸条及び凹条の少なくとも一方の端部における平坦面とでなす角度が４５度以上６０度以下であってもよい。本発明に係る導光板において、複数の凸条及び凹条の少なくとも一方を除いた導光板の厚みが０．２ｍｍ以上１．０ｍｍ以下であってもよい。本発明に係る導光板において、複数の凸条及び凹条の少なくとも一方が隙間なく平板部の平面に配置されていてもよい。本発明に係る導光板において、複数の凸条及び凹条の少なくとも一方が一定の間隔を空けて平板部の平面に配置され、出光面は、複数の凸条及び凹条の少なくとも一方の傾斜面と平面とによって形成されてもよい。 In the light guide plate according to the present invention, the angle formed by the flat surface of the flat plate portion and the tangent of the inclined surface at the end of at least one of the ridge and the groove may be 45 degrees or more and 60 degrees or less. In the light guide plate according to the present invention, the inclined surface may include a curved surface. In the light guide plate according to the present invention, the inclined surface includes a curved surface and a flat surface, and the angle between the flat surface and the flat surface at the end of at least one of the ridge and the groove is 30 degrees or more and 70 degrees or less Good. In the light guide plate according to the present invention, the inclined surface includes a curved surface and a flat surface, and the angle between the flat surface and the flat surface at the end of at least one of the ridge and the groove is 45 degrees or more and 60 degrees or less Good. In the light guide plate according to the present invention, the thickness of the light guide plate excluding at least one of the plurality of ridges and grooves may be 0.2 mm or more and 1.0 mm or less. In the light guide plate according to the present invention, at least one of the plurality of convex lines and concave lines may be disposed on the flat surface of the flat plate without a gap. In the light guide plate according to the present invention, at least one of the plurality of ridges and grooves is disposed on a flat surface of the flat plate portion at a constant interval, and the light exit surface is an inclined surface of at least one of the plurality of ridges and grooves. And a plane.
　また、本発明は、光が入射する入光面を側方に有し、入光面から入射する光を出光面から出射する概略平板状の導光板であって、平板部と、平板部の平面に設けられ、平面の法線方向から見て、入光面に対して垂直方向に延在する複数の凸条及び凹条の少なくとも一方と、を備え、複数の凸条及び凹条の少なくとも一方が一定の間隔を空けて前記平面に配置され、複数の凸条及び凹条の少なくとも一方は平面に対して傾斜する傾斜面を有し、出光面は、複数の凸条及び凹条の少なくとも一方の傾斜面と平面とによって形成され、平面と凸条及び凹条の少なくとも一方の端部における傾斜面の接線とでなす角度が３０度以上８０度以下である、導光板である。 Further, the present invention is a substantially flat light guide plate having a light incident surface on which light is incident on a side and emitting light incident from the light incident surface from a light emitting surface, and is a flat plate portion and a flat plate portion. And at least one of a plurality of ridges and grooves extending in a direction perpendicular to the light entrance surface, provided in a plane and viewed in a direction normal to the plane, at least one of the plurality of ridges and grooves At least one of the plurality of ridges and grooves is disposed on the plane at a predetermined interval, and at least one of the plurality of ridges and grooves has an inclined surface which is inclined with respect to the plane, and the light exit surface is at least a plurality of ridges and grooves It is a light guide plate which is formed by one inclined surface and a plane, and which makes an angle of 30 degrees or more and 80 degrees or less with a plane and a tangent of an inclined surface in at least one end of a ridge and a groove.
　本発明に係る導光板によれば、導光板が備える平板部に複数の凸条及び凹条の少なくとも一方を一定の間隔を空けて配置し、平板部の平面と凸条及び凹条の少なくとも一方の端部における傾斜面の接線とでなす角度を３０度以上８０度以下とすることにより、導光板の出光面から出射される光の輝度の広がりを抑制することができる。 According to the light guide plate according to the present invention, at least one of the plurality of ridges and grooves is disposed at a constant interval on the flat plate portion of the light guide plate, and at least one of the flat surface of the flat plate portion and the ridges and grooves By setting the angle formed by the tangent of the inclined surface at the end of the light source to 30 degrees or more and 80 degrees or less, the spread of the luminance of the light emitted from the light exit surface of the light guide plate can be suppressed.
　本発明に係る面光源装置は、本発明に係る導光板と、入光面と対向する位置に配置された光源と、を備える。本発明に係る面光源装置は、本発明に係る導光板と、第１の光源と、第２の光源と、を備え、入光面は、第１の入光面及び第２の入光面を含み、第１の入光面と第２の入光面とが対向しており、第１の光源は、第１の入光面と対向する位置に配置され、第２の光源は、第２の入光面と対向する位置に配置されている。本発明に係る表示装置は、本発明に係る面光源装置と、面光源装置から出射される光を受ける表示パネルと、を備える。本発明に係る電子機器は、本発明に係る表示装置を備える。 A surface light source device according to the present invention includes the light guide plate according to the present invention, and a light source disposed at a position facing the light incident surface. A surface light source device according to the present invention includes the light guide plate according to the present invention, a first light source, and a second light source, and the light incident surface is a first light incident surface and a second light incident surface. And the first light incident surface is opposite to the second light incident surface, the first light source is disposed at a position facing the first light incident surface, and the second light source is It is arrange | positioned in the position which opposes the 2 light-incidence surface. A display device according to the present invention includes the surface light source device according to the present invention, and a display panel that receives light emitted from the surface light source device. An electronic device according to the present invention includes the display device according to the present invention.
　本発明によれば、導光板の出光面から出射される光の輝度の広がりを抑制することができる。 According to the present invention, the spread of the luminance of the light emitted from the light exit surface of the light guide plate can be suppressed.
図１は、実施形態に係る液晶表示装置の構成を例示する斜視図である。FIG. 1 is a perspective view illustrating the configuration of the liquid crystal display device according to the embodiment. 図２は、実施形態に係る面光源装置の構成を例示する斜視図である。FIG. 2 is a perspective view illustrating the configuration of the surface light source device according to the embodiment. 図３Ａは、実施形態に係る導光板を示す図である。FIG. 3A is a view showing a light guide plate according to the embodiment. 図３Ｂは、実施形態に係る導光板を示す図である。FIG. 3B is a view showing a light guide plate according to the embodiment. 図４Ａは、導光板の上面から出射される光束の幅と、レンチキュラーの角度との関係を説明する図である。FIG. 4A is a view for explaining the relationship between the width of a light beam emitted from the upper surface of the light guide plate and the angle of the lenticular. 図４Ｂは、導光板の上面から出射される光束の幅と、レンチキュラーの角度との関係を説明する図である。FIG. 4B is a view for explaining the relationship between the width of a light beam emitted from the upper surface of the light guide plate and the angle of the lenticular. 図４Ｃは、導光板の上面から出射される光束の幅と、レンチキュラーの角度との関係を説明する図である。FIG. 4C is a view for explaining the relationship between the width of a light beam emitted from the upper surface of the light guide plate and the angle of the lenticular. 図５Ａは、導光板の上面から出射される光の輝度分布を示す図である。FIG. 5A is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate. 図５Ｂは、導光板の上面から出射される光の輝度分布を示す図である。FIG. 5B is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate. 図５Ｃは、導光板の上面から出射される光の輝度分布を示す図である。FIG. 5C is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate. 図６は、導光板の上面から出射される光の輝度と、レンチキュラーの角度との関係を示す図である。FIG. 6 is a view showing the relationship between the luminance of light emitted from the upper surface of the light guide plate and the angle of the lenticular. 図７は、導光板の上面から出射される光の輝度の半値全幅の説明図である。FIG. 7 is an explanatory view of the full width half maximum of the luminance of light emitted from the upper surface of the light guide plate. 図８は、コントラスト比と、レンチキュラーの角度との関係を示す図である。FIG. 8 is a diagram showing the relationship between the contrast ratio and the angle of the lenticular. 図９は、コントラスト比の説明図である。FIG. 9 is an explanatory view of the contrast ratio. 図１０は、導光板の上面から出射される光の輝度分布を示す図である。FIG. 10 is a diagram showing the luminance distribution of light emitted from the upper surface of the light guide plate. 図１１は、導光板の厚みと、コントラスト比と、レンチキュラーの角度との関係を示す図である。FIG. 11 is a view showing the relationship between the thickness of the light guide plate, the contrast ratio, and the angle of the lenticular. 図１２Ａは、導光板の上面から出射される光の輝度分布を示す図である。FIG. 12A is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate. 図１２Ｂは、導光板の上面から出射される光の輝度分布を示す図である。FIG. 12B is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate. 図１３Ａは、実施形態に係る導光板を示す図である。FIG. 13A is a view showing a light guide plate according to the embodiment. 図１３Ｂは、導光板の上面から出射される光の輝度分布を示す図である。FIG. 13B is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate. 図１３Ｃは、平坦部が設けられていない導光板及び平坦部が設けられた導光板におけるコントラスト比を示す図である。FIG. 13C is a view showing a contrast ratio in a light guide plate in which a flat portion is not provided and a light guide plate in which a flat portion is provided. 図１４Ａは、実施形態に係る導光板を示す図である。FIG. 14A is a view showing a light guide plate according to the embodiment. 図１４Ｂは、実施形態に係る導光板を示す図である。FIG. 14B is a view showing a light guide plate according to the embodiment. 図１５は、実施形態に係る導光板を示す図である。FIG. 15 is a view showing a light guide plate according to the embodiment. 図１６Ａは、実施形態に係る導光板を示す図である。FIG. 16A is a view showing a light guide plate according to the embodiment. 図１６Ｂは、実施形態に係る導光板を示す図である。FIG. 16B is a view showing a light guide plate according to the embodiment. 図１７は、実施形態に係る導光板を示す図である。FIG. 17 is a view showing a light guide plate according to the embodiment. 図１８は、実施形態に係る導光板を示す図である。FIG. 18 is a view showing a light guide plate according to the embodiment. 図１９Ａは、実施形態に係る導光板を示す図である。FIG. 19A is a view showing a light guide plate according to the embodiment. 図１９Ｂは、実施形態に係る導光板を示す図である。FIG. 19B is a view showing a light guide plate according to the embodiment. 図１９Ｃは、実施形態に係る導光板を示す図である。FIG. 19C is a view showing a light guide plate according to the embodiment. 図１９Ｄは、実施形態に係る導光板を示す図である。FIG. 19D is a view showing a light guide plate according to the embodiment. 図１９Ｅは、実施形態に係る導光板を示す図である。FIG. 19E is a view showing a light guide plate according to the embodiment. 図２０Ａは、導光板の上面から出射される光の輝度分布を示す図である。FIG. 20A is a view showing a luminance distribution of light emitted from the upper surface of the light guide plate. 図２０Ｂは、導光板におけるコントラスト比を示す図である。FIG. 20B is a diagram showing the contrast ratio in the light guide plate. 図２１Ａは、実施形態に係る導光板を示す図である。FIG. 21A is a view showing a light guide plate according to the embodiment. 図２１Ｂは、実施形態に係る導光板を示す図である。FIG. 21B is a view showing a light guide plate according to the embodiment. 図２１Ｃは、実施形態に係る導光板を示す図である。FIG. 21C is a view showing a light guide plate according to the embodiment. 図２２Ａは、実施形態に係る導光板を示す図である。FIG. 22A is a view showing a light guide plate according to the embodiment. 図２２Ｂは、実施形態に係る導光板を示す図である。FIG. 22B is a view showing a light guide plate according to the embodiment. 図２２Ｃは、実施形態に係る導光板を示す図である。FIG. 22C is a view showing a light guide plate according to the embodiment. 図２３Ａは、実施形態に係る導光板を示す図である。FIG. 23A is a view showing a light guide plate according to the embodiment. 図２３Ｂは、実施形態に係る導光板を示す図である。FIG. 23B is a view showing a light guide plate according to the embodiment. 図２３Ｃは、実施形態に係る導光板を示す図である。FIG. 23C is a view showing a light guide plate according to the embodiment.
　以下、本発明の実施の形態を、図面に基づいて説明する。なお、以下に説明する実施の形態は、本発明を実施する一例を示すものであって、本発明を以下に説明する具体的な構成に限定するものではない。 Hereinafter, embodiments of the present invention will be described based on the drawings. The embodiments described below are merely examples for practicing the present invention, and the present invention is not limited to the specific configurations described below.
　以下の実施形態では、「表示装置」は、液晶表示装置として説明され、「面光源装置」は、液晶表示装置のバックライトユニットとして説明される。なお、「面光源装置」は、表示パネルや電子ペーパによる表示装置の前面に配置されるフロントライト等、バックライトユニット以外の用途で利用されてもよい。 In the following embodiments, “display device” is described as a liquid crystal display device, and “surface light source device” is described as a backlight unit of a liquid crystal display device. The “surface light source device” may be used in applications other than a backlight unit, such as a front light disposed on the front of a display device or a display device made of electronic paper.
　（液晶表示装置の構成）
　図１は、実施形態に係る液晶表示装置の構成を例示する斜視図である。図１に示すように、液晶表示装置は、バックライトユニットとして配置される面光源装置１と、面光源装置１から出射される光を受ける表示パネル２とを備える。表示パネル２は、ガラス板に挟まれて封入された液晶に電圧をかけて光の透過率を増減等させることで、像を表示する。以下、面光源装置１における、表示パネル２側を上面側として、その反対面側を下面側として説明することがある。 (Configuration of liquid crystal display)
FIG. 1 is a perspective view illustrating the configuration of the liquid crystal display device according to the embodiment. As shown in FIG. 1, the liquid crystal display device includes a surface light source device 1 disposed as a backlight unit, and a display panel 2 that receives light emitted from the surface light source device 1. The display panel 2 displays an image by applying a voltage to the liquid crystal sandwiched between the glass plates to increase or decrease the light transmittance. Hereinafter, in the surface light source device 1, the display panel 2 side may be described as the upper surface side, and the opposite surface side may be described as the lower surface side.
　（面光源装置１の構成）
　図２は、実施形態に係る面光源装置１の構成を例示する斜視図である。実施形態に係る面光源装置１は、導光板１０、光源１１、フレキシブルプリント基板（以下、「ＦＰＣ」とも表記する）１２、固定部材１３及びフレーム１４を備える。また、面光源装置１は、導光板１０の下面側に配置される反射シート１５、導光板１０の上面側に順に積層される拡散シート１６、プリズムシート１７及び遮光両面テープ１８を備える。 (Configuration of surface light source device 1)
FIG. 2 is a perspective view illustrating the configuration of the surface light source device 1 according to the embodiment. The surface light source device 1 according to the embodiment includes a light guide plate 10, a light source 11, a flexible printed circuit board (hereinafter also referred to as “FPC”) 12, a fixing member 13, and a frame 14. The surface light source device 1 further includes a reflective sheet 15 disposed on the lower surface side of the light guide plate 10, a diffusion sheet 16 sequentially laminated on the upper surface side of the light guide plate 10, a prism sheet 17, and a light shielding double-sided tape 18.
　導光板１０は、概略平板状であり、ポリカーボネート樹脂やポリメチルメタクリレート樹脂等の透光性の素材で形成されている。導光板１０の上面は、光が出射する出光面であり、表示パネル２と向かい合う面である。導光板１０は、光源１１から導光板１０内に入射された光を出光面に導き、出光面の全体又は一部分が光る。導光板１０は、導光板本体と、導光板本体の高さよりも高い光導入部とを備えてもよい。光源１１から出射された光が、光導入部から導光板本体内に効率よく入射し、導光板１０の光利用効率が向上する。導光板本体が光導入部よりも薄いことで、面光源装置１の薄型化が向上し、面光源装置１を備える液晶表示装置の薄型化が向上する。ただし、実施形態に係る導光板１０は、光導入部を有しない平板形状であってもよい。 The light guide plate 10 has a substantially flat plate shape, and is formed of a translucent material such as polycarbonate resin or polymethyl methacrylate resin. The upper surface of the light guide plate 10 is a light emitting surface from which light is emitted, and is a surface facing the display panel 2. The light guide plate 10 guides the light incident from the light source 11 into the light guide plate 10 to the light exit surface, and all or part of the light exit surface is illuminated. The light guide plate 10 may include a light guide plate main body and a light introducing portion which is higher than the height of the light guide plate main body. The light emitted from the light source 11 efficiently enters the light guide plate main body from the light introducing portion, and the light use efficiency of the light guide plate 10 is improved. Since the light guide plate main body is thinner than the light introducing portion, the reduction in thickness of the surface light source device 1 is improved, and the reduction in thickness of the liquid crystal display device including the surface light source device 1 is improved. However, the light guide plate 10 according to the embodiment may have a flat plate shape without the light introducing portion.
　光源１１は、白色光を蛍光部から出射する。光源１１は、例えば、ＬＥＤパッケージであるが、ＬＥＤパッケージ以外の光源が用いられてもよい。光源１１は、発光素子であるＬＥＤチップが蛍光体を含む透光性樹脂（樹脂層）で封止されて形成されている。若しくは、ＬＥＤチップ上に蛍光体を配置せずに、導光板１０の出光面上に蛍光体層を配置してもよいし、反射シート１５上に蛍光体層を配置してもよい。光源１１は、ＦＰＣ１２からの給電を受けて駆動し、点灯する。なお、光源１１として、白色以外のＬＥＤ光源が用いられてもよい。光源１１は、導光板１０の入光面と対向する位置に配置されている。例えば、光源１１の発光面が、導光板１０の入光面と対向するようにして、光源１１がＦＰＣ１２に実装されている。ＦＰＣ１２に複数の光源１１が一定の間隔で一列に実装されてもよい。 The light source 11 emits white light from the fluorescent unit. The light source 11 is, for example, an LED package, but a light source other than the LED package may be used. The light source 11 is formed by sealing an LED chip, which is a light emitting element, with a translucent resin (resin layer) containing a phosphor. Alternatively, the phosphor layer may be disposed on the light emitting surface of the light guide plate 10 without disposing the phosphor on the LED chip, or the phosphor layer may be disposed on the reflective sheet 15. The light source 11 receives power supply from the FPC 12 and is driven to light. In addition, LED light sources other than white may be used as the light source 11. The light source 11 is disposed at a position facing the light incident surface of the light guide plate 10. For example, the light source 11 is mounted on the FPC 12 so that the light emitting surface of the light source 11 faces the light incident surface of the light guide plate 10. A plurality of light sources 11 may be mounted on the FPC 12 in a row at regular intervals.
　ＦＰＣ１２は、可撓性のある絶縁性フィルムである基材に、導体箔によって配線を設け、表面に保護用の絶縁性フィルムであるカバーレイ又はレジン（感光性樹脂）を接着させて構成される配線基板である。ＦＰＣ１２に配線が設けられている。ＦＰＣ１２の配線は、光源１１への電力供給等に用いられる。固定部材１３は、ＦＰＣ１２の下面等に配置され、ＦＰＣ１２を導光板１０に固定する。固定部材１３は、例えば、上下面が粘着面となった両面粘着テープである。 The FPC 12 is configured by providing a wiring with a conductor foil on a flexible insulating film base material, and adhering a cover lay or resin (photosensitive resin), which is an insulating film for protection, on the surface. It is a wiring board. Wiring is provided on the FPC 12. The wiring of the FPC 12 is used to supply power to the light source 11 or the like. The fixing member 13 is disposed on the lower surface or the like of the FPC 12 and fixes the FPC 12 to the light guide plate 10. The fixing member 13 is, for example, a double-sided adhesive tape whose upper and lower surfaces are adhesive surfaces.
　フレーム１４は、導光板１０、光源１１、ＦＰＣ１２、固定部材１３、反射シート１５、拡散シート１６及びプリズムシート１７を収容する。フレーム１４は、導光板１０の側面を囲む枠体（枠状部材）であってもよいし、導光板１０の側面を囲む枠体と、枠体が立設された底板とを有する箱体（箱状部材）であってもよい。枠体は、４辺の側壁部材、開口を有する円形の側壁部材又は開口を有する楕円形の側壁部材によって形成されていてもよい。また、枠体の４辺の側壁部材のコーナー部分が直角形状であってもよいし、枠体の４辺の側壁部材のコーナー部分がＲ形状であってもよい。 The frame 14 accommodates the light guide plate 10, the light source 11, the FPC 12, the fixing member 13, the reflection sheet 15, the diffusion sheet 16, and the prism sheet 17. The frame 14 may be a frame (frame-like member) surrounding the side surface of the light guide plate 10, or a box body having a frame surrounding the side surface of the light guide plate 10 and a bottom plate on which the frame is erected It may be a box-like member). The frame may be formed by four side wall members, a circular side wall member having an opening, or an elliptical side wall member having an opening. Further, the corner portions of the side wall members on the four sides of the frame may have a right-angled shape, and the corner portions of the side wall members on the four sides of the frame may have an R shape.
　反射シート１５は、導光板１０の下面と接するようにして配置される。導光板１０の下面は、導光板１０の上面の反対側の面である。反射シート１５は、多層膜構造を有する高反射フィルムまたは反射率の高い白色樹脂シートや金属箔等からなる平滑なシートであり、導光板１０内の光が面光源装置１の下面から漏れないように光を反射する。フレーム１４が、枠体及び底板を有する箱体である場合、反射シート１５は、導光板１０とフレーム１４の底板との間に配置される。 The reflective sheet 15 is disposed in contact with the lower surface of the light guide plate 10. The lower surface of the light guide plate 10 is a surface opposite to the upper surface of the light guide plate 10. The reflection sheet 15 is a smooth sheet made of a high reflection film having a multilayer film structure, a white resin sheet having a high reflectance, a metal foil or the like, and light in the light guide plate 10 does not leak from the lower surface of the surface light source device 1 Reflect light. When the frame 14 is a box having a frame and a bottom plate, the reflective sheet 15 is disposed between the light guide plate 10 and the bottom plate of the frame 14.
　導光板１０上に、拡散シート１６と、１枚又は２枚のプリズムシート１７と、が配置される。拡散シート１６は、半透明な樹脂フィルムであり、導光板１０の出光面から出射された光を拡散させて光の指向特性を広げる。プリズムシート１７は、上面に三角プリズム状の微細なパターンが形成された透明な樹脂フィルムであり、拡散シート１６によって拡散された光を集光し、面光源装置１を上面側から見た場合の輝度を上昇させる。遮光両面テープ１８は、上下両面が粘着面となった黒色の粘着テープである。遮光両面テープ１８は、額縁状（リング状）である。遮光両面テープ１８は、フレーム１４の外周部分に沿って配置され、面光源装置１の外部に光が漏れ出ることを抑制している。 A diffusion sheet 16 and one or two prism sheets 17 are disposed on the light guide plate 10. The diffusion sheet 16 is a translucent resin film, and diffuses the light emitted from the light emitting surface of the light guide plate 10 to widen the directivity of light. The prism sheet 17 is a transparent resin film on the upper surface of which a fine pattern in the form of a triangular prism is formed, and condenses the light diffused by the diffusion sheet 16 when the surface light source device 1 is viewed from the upper surface Increase the brightness. The light shielding double-sided tape 18 is a black adhesive tape whose upper and lower surfaces are adhesive surfaces. The light shielding double-sided tape 18 has a frame shape (ring shape). The light shielding double-sided tape 18 is disposed along the outer peripheral portion of the frame 14 to suppress the leakage of light to the outside of the surface light source device 1.
　（導光板１０の構成）
　図３Ａ及び図３Ｂは、実施形態に係る導光板１０を示す図である。導光板１０は、光源１１から出射された光が入射する入光面２０と、入光面２０から入射する光を出射する出光面とを有する。導光板１０の出光面は、表示パネル２側に向けられており、以下では、導光板１０の出光面を、導光板１０の上面２１とし、導光板１０の出光面の反対側の面（反対面）を、導光板１０の下面２２として説明する。導光板１０の下面２２は、導光板１０の入光面２０に対して略９０度傾いている。光源１１から出射された光は、導光板１０の入光面２０から導光板１０の内部に入り、導光板１０の上面２１及び下面２２で全反射を繰り返しながら導光板１０の内部を進む。導光板１０の上面２１に入射する光が、臨界角よりも小さな入射角で入射すると、導光板１０の上面２１から外部に光が出射される。 (Configuration of light guide plate 10)
Drawing 3A and Drawing 3B are figures showing light guide plate 10 concerning an embodiment. The light guide plate 10 has an incident surface 20 on which the light emitted from the light source 11 is incident, and an exit surface on which the light incident from the incident surface 20 is emitted. The light exit surface of the light guide plate 10 is directed to the display panel 2 side, and hereinafter, the light exit surface of the light guide plate 10 is the upper surface 21 of the light guide plate 10, and the surface opposite to the light exit surface of the light guide plate 10 The surface) is described as the lower surface 22 of the light guide plate 10. The lower surface 22 of the light guide plate 10 is inclined approximately 90 degrees with respect to the light incident surface 20 of the light guide plate 10. The light emitted from the light source 11 enters the inside of the light guide plate 10 from the light incident surface 20 of the light guide plate 10 and travels the inside of the light guide plate 10 while repeating total reflection on the upper surface 21 and the lower surface 22 of the light guide plate 10. When light incident on the upper surface 21 of the light guide plate 10 is incident at an incident angle smaller than the critical angle, light is emitted from the upper surface 21 of the light guide plate 10 to the outside.
　図３Ｂに示すように、導光板１０は、平板部３０と、平板部３０の平面３１に設けられた複数のレンチキュラー２３を備える。図３Ｂは、実施形態に係る導光板１０を示す図であって、図３Ｂは、導光板１０の入光面２０側から見た場合の導光板１０が示されている。複数のレンチキュラー２３は、曲面２３Ａを有している。曲面２３Ａは、平面３１に対して傾斜している。したがって、レンチキュラー２３は平面３１に対して傾斜する傾斜面を有する。複数のレンチキュラー２３の曲面２３Ａによって、導光板１０の上面２１が形成されている。各レンチキュラー２３は、平板部３０の平面３１の法線方向から見て、導光板１０の入光面２０に対して垂直方向に延在する凸条である。したがって、レンチキュラー２３の曲面２３Ａが、平板部３０の平面３１の法線方向に向かって平板部３０の平面３１よりも突出している。導光板１０がレンチキュラー２３を備えることにより、導光板１０の上面２１から出射される光の分布が制御され、導光板１０の上面２１から出射される光の輝度分布を制御できる。複数のレンチキュラー２３は、互いに平行に並んで配置されている。複数のレンチキュラー２３は、連続して配置されており、隣り合う２つのレンチキュラー２３同士が繋がっている。したがって、複数のレンチキュラー２３が、平板部３０の平面３１に隙間なく配置されている。レンチキュラー２３の幅（レンチキュラー２３の短手方向の長さ）と、レンチキュラー２３のピッチとが同一である。レンチキュラー２３は、射出成形によって製造される導光板１０に一体に形成されてもよい。 As shown in FIG. 3B, the light guide plate 10 includes a flat plate portion 30 and a plurality of lenticulars 23 provided on the flat surface 31 of the flat plate portion 30. FIG. 3B is a view showing the light guide plate 10 according to the embodiment, and FIG. 3B shows the light guide plate 10 as viewed from the light incident surface 20 side of the light guide plate 10. The plurality of lenticulars 23 have curved surfaces 23A. The curved surface 23A is inclined with respect to the plane 31. Therefore, the lenticular 23 has an inclined surface which is inclined with respect to the plane 31. The upper surface 21 of the light guide plate 10 is formed by the curved surfaces 23A of the plurality of lenticulars 23. Each lenticular 23 is a ridge extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 when viewed in the normal direction of the flat surface 31 of the flat plate portion 30. Therefore, the curved surface 23 A of the lenticular 23 protrudes from the plane 31 of the flat plate portion 30 in the normal direction of the plane 31 of the flat plate portion 30. By providing the light guide plate 10 with the lenticular 23, the distribution of light emitted from the upper surface 21 of the light guide plate 10 can be controlled, and the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10 can be controlled. The plurality of lenticulars 23 are arranged parallel to one another. The plurality of lenticulars 23 are continuously arranged, and two adjacent lenticulars 23 are connected to each other. Therefore, the plurality of lenticulars 23 are disposed on the flat surface 31 of the flat plate portion 30 without a gap. The width of the lenticular 23 (the length in the short direction of the lenticular 23) and the pitch of the lenticular 23 are the same. The lenticular 23 may be integrally formed on the light guide plate 10 manufactured by injection molding.
　図４Ａ～図４Ｃは、導光板１０の上面２１から出射される光束の幅と、レンチキュラー２３の角度との関係を説明する図である。図４Ａ及び図４Ｂは、導光板１０の入光面２０側から見た場合の導光板１０が示されている。図４Ａに示すレンチキュラー２３の角度は、図４Ｂに示すレンチキュラー２３の角度よりも小さい。レンチキュラー２３の角度は、レンチキュラー２３の接触角である。すなわち、レンチキュラー２３の角度は、平板部３０の平面３１と、レンチキュラー２３の端部における曲面２３Ａの接線Ｌ１とでなす角度（θ）である（図４Ｃ参照）。例えば、レンチキュラー２３の角度が小さくなると、導光板１０の上面２１への入射光に対するレンチキュラー２３の曲面の角度が小さくなるため、光の入射角が臨界角度を越えづらくなり、導光板１０の上面２１から光が出射されにくくなる。したがって、図４Ａに示すように、レンチキュラー２３の角度が小さくなると、導光板１０の上面２１から出射される光束の幅Ｗ１が広くなる。例えば、レンチキュラー２３の角度が大きくなると、導光板１０の上面２１への入射光に対するレンチキュラー２３の曲面の角度が大きくなるため、入射角が臨界角度を越えやすくなり、導光板１０の上面２１から光が出射されやすくなる。図４Ｂに示すように、レンチキュラー２３の角度が大きくなると、導光板１０の上面２１から出射される光束の幅Ｗ２が狭くなる。このように、レンチキュラー２３の角度が大きいほど、導光板１０の上面２１から光が出射しやすいため、導光板１０の上面２１から出射される光の輝度分布を制御しやすくなる。 FIGS. 4A to 4C are diagrams for explaining the relationship between the width of the light beam emitted from the upper surface 21 of the light guide plate 10 and the angle of the lenticular 23. FIG. 4A and FIG. 4B show the light guide plate 10 as viewed from the light incident surface 20 side of the light guide plate 10. The angle of the lenticular 23 shown in FIG. 4A is smaller than the angle of the lenticular 23 shown in FIG. 4B. The angle of the lenticular 23 is the contact angle of the lenticular 23. That is, the angle of the lenticular 23 is an angle (θ) formed by the flat surface 31 of the flat plate portion 30 and the tangent L1 of the curved surface 23A at the end of the lenticular 23 (see FIG. 4C). For example, when the angle of the lenticular 23 decreases, the angle of the curved surface of the lenticular 23 with respect to the light incident on the upper surface 21 of the light guide plate 10 decreases, so the incident angle of light hardly exceeds the critical angle. Light is less likely to be emitted from Therefore, as shown in FIG. 4A, when the angle of the lenticular 23 decreases, the width W1 of the light beam emitted from the upper surface 21 of the light guide plate 10 widens. For example, when the angle of the lenticular 23 increases, the angle of the curved surface of the lenticular 23 with respect to incident light on the upper surface 21 of the light guide plate 10 increases, so the incident angle easily exceeds the critical angle. Is more likely to be emitted. As shown in FIG. 4B, when the angle of the lenticular 23 increases, the width W2 of the light beam emitted from the upper surface 21 of the light guide plate 10 narrows. As described above, since the light is more easily emitted from the upper surface 21 of the light guide plate 10 as the angle of the lenticular 23 is larger, the luminance distribution of the light emitted from the upper surface 21 of the light guide plate 10 can be easily controlled.
　図５Ａ～図５Ｃには、導光板１０の上面２１から出射される光の輝度分布が示されている。図５Ａに示す導光板１０のレンチキュラー２３の角度は、図５Ｂに示す導光板１０のレンチキュラー２３の角度よりも小さい。図５Ａ及び図５Ｂでは、一つの光源１１から出射された光が、導光板１０に入射されている。図５Ａに示すように、導光板１０の上面２１から出射される光の輝度が、導光板１０の横幅方向（図５ＡのＸ方向）に広がっている。導光板１０の横幅方向は、光源１１の光軸と直交する方向である。 5A to 5C show the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10. As shown in FIG. The angle of the lenticulars 23 of the light guide plate 10 shown in FIG. 5A is smaller than the angle of the lenticulars 23 of the light guide plate 10 shown in FIG. 5B. In FIGS. 5A and 5B, light emitted from one light source 11 is incident on the light guide plate 10. As shown to FIG. 5A, the brightness | luminance of the light radiate | emitted from the upper surface 21 of the light-guide plate 10 has spread in the width direction (X direction of FIG. 5A) of the light-guide plate 10. FIG. The lateral width direction of the light guide plate 10 is a direction orthogonal to the optical axis of the light source 11.
　これに対して、図５Ｂに示すように、導光板１０の上面２１から出射される光の輝度が、導光板１０の横幅方向（図５ＢのＸ方向）に向かって広がることが抑制されている。図５Ｃは、導光板１０の上面２１から出射される光の輝度の広がりを示している。図５Ｃの縦軸は、導光板１０の上面２１から出射される光の輝度であり、図５Ｃの横軸は、導光板１０の横幅（ｍｍ）である。図５Ｃの点線Ｃは、図５Ａの一点鎖線Ａ－Ａにおいて、導光板１０の上面２１から出射される光の輝度である。図５Ｃの実線Ｄは、図５Ｂの一点鎖線Ｂ－Ｂにおいて、導光板１０の上面２１から出射される光の輝度である。 On the other hand, as shown to FIG. 5B, it is suppressed that the brightness | luminance of the light radiate | emitted from the upper surface 21 of the light-guide plate 10 is spread toward the width direction (X direction of FIG. 5B) of the light-guide plate 10. . FIG. 5C shows the spread of the luminance of the light emitted from the upper surface 21 of the light guide plate 10. The vertical axis in FIG. 5C is the brightness of light emitted from the upper surface 21 of the light guide plate 10, and the horizontal axis in FIG. 5C is the horizontal width (mm) of the light guide plate 10. The dotted line C in FIG. 5C is the brightness of the light emitted from the upper surface 21 of the light guide plate 10 at the alternate long and short dash line AA in FIG. 5A. The solid line D in FIG. 5C is the brightness of light emitted from the upper surface 21 of the light guide plate 10 at the alternate long and short dash line BB in FIG. 5B.
　図６は、導光板１０の上面２１から出射される光の輝度と、レンチキュラー２３の角度との関係を示す図である。図６の縦軸は、導光板１０の上面２１から出射される光の輝度の半値全幅であり、図６の横軸は、レンチキュラー２３の角度である。導光板１０の上面２１から出射される光の輝度の半値全幅とは、図７に示すように、導光板１０の上面２１から出射される光の輝度のピークの半分の値における幅（Ｗ３）である。図７の縦軸は、導光板１０の上面２１から出射される光の輝度であり、図７の横軸は、光源１１の光軸からの距離である。図６において、レンチキュラー２３の角度が１５度である場合の半値全幅を１．０としてプロットしている。図６におけるレンチキュラー２３の角度が３０度、４５度、６０度、７５度である場合の半値全幅は、レンチキュラー２３の角度が１５度である場合の半値全幅に対する比である。図６に示すように、レンチキュラー２３の角度が３５度以上７５度以下である場合の半値全幅は、レンチキュラー２３の角度が１５度である場合の半値全幅の半分以下である。 FIG. 6 is a view showing the relationship between the brightness of light emitted from the upper surface 21 of the light guide plate 10 and the angle of the lenticular 23. The vertical axis in FIG. 6 is the full width half maximum of the luminance of light emitted from the upper surface 21 of the light guide plate 10, and the horizontal axis in FIG. 6 is the angle of the lenticular 23. The full width at half maximum of the luminance of light emitted from the upper surface 21 of the light guide plate 10 is, as shown in FIG. 7, the width at half the peak value of the luminance of light emitted from the upper surface 21 of the light guide plate 10 (W3) It is. The vertical axis in FIG. 7 is the brightness of light emitted from the upper surface 21 of the light guide plate 10, and the horizontal axis in FIG. 7 is the distance from the optical axis of the light source 11. In FIG. 6, the full width at half maximum in the case where the angle of the lenticular 23 is 15 degrees is plotted as 1.0. The full width at half maximum when the angle of the lenticular 23 in FIG. 6 is 30, 45, 60, and 75 degrees is a ratio to the full width at half maximum when the angle of the lenticular 23 is 15 degrees. As shown in FIG. 6, the full width at half maximum when the angle of the lenticular 23 is 35 degrees or more and 75 degrees or less is not more than half the full width at half maximum when the angle of the lenticular 23 is 15 degrees.
　図８は、コントラスト比と、レンチキュラー２３の角度との関係を示す図である。図８の縦軸は、コントラスト比であり、図８の横軸は、レンチキュラー２３の角度である。図８には、導光板１０の厚みが０．４ｍｍである場合のコントラスト比が示されている。導光板１０の厚みは、レンチキュラー２３の高さを除外している。すなわち、レンチキュラー２３の部分を除いた導光板１０の厚みが０．４ｍｍである。コントラスト比は、導光板１０の上面２１から出射される光の輝度の低い部分（低輝度部、図９のＡ点）を、導光板１０の上面２１から出射される光の輝度のピーク（輝度ピーク、図９のＢ点）で割った値である。図９の縦軸は、導光板１０の上面２１から出射される光の輝度であり、図９の横軸は、光源１１の光軸からの距離である。光源１１の光軸から図９のＡ点までの距離は、１００ｍｍである。図８に示すように、レンチキュラー２３の角度が３０度以上７０度以下の範囲において、コントラスト比が１／５０００以下であり、レンチキュラー２３の角度が４５度以上６０度以下の範囲において、コントラスト比が１／１００００付近の値である。図８に示すように、レンチキュラー２３の角度が３０度以上７０度以下の範囲において、レンチキュラー２３の角度が１５度である場合と比較して、コントラスト比が３倍以上に向上している。 FIG. 8 is a diagram showing the relationship between the contrast ratio and the angle of the lenticular 23. The vertical axis in FIG. 8 is the contrast ratio, and the horizontal axis in FIG. 8 is the angle of the lenticular 23. FIG. 8 shows the contrast ratio when the thickness of the light guide plate 10 is 0.4 mm. The thickness of the light guide plate 10 excludes the height of the lenticular 23. That is, the thickness of the light guide plate 10 excluding the portion of the lenticular 23 is 0.4 mm. The contrast ratio is the peak of the luminance of the light emitted from the upper surface 21 of the light guide plate 10 at the low luminance part (low luminance part, point A in FIG. 9) of the light emitted from the upper surface 21 of the light guide plate 10 The peak value is a value divided by point B) in FIG. The vertical axis in FIG. 9 is the brightness of light emitted from the upper surface 21 of the light guide plate 10, and the horizontal axis in FIG. 9 is the distance from the optical axis of the light source 11. The distance from the optical axis of the light source 11 to the point A in FIG. 9 is 100 mm. As shown in FIG. 8, the contrast ratio is 1/5000 or less when the angle of the lenticular 23 is in the range of 30 degrees to 70 degrees, and the contrast ratio is in the range of 45 degrees to 60 degrees of the lenticular 23 It is a value around 1/10000. As shown in FIG. 8, in the range of the angle of the lenticular 23 in the range of 30 degrees to 70 degrees, the contrast ratio is improved by three times or more as compared with the case where the angle of the lenticular 23 is 15 degrees.
　図１０には、レンチキュラー２３の角度が４５度である場合における導光板１０の上面２１から出射される光の輝度分布と、レンチキュラー２３の角度が７５度である場合における導光板１０の上面２１から出射される光の輝度分布とが示されている。図１０の縦軸は、導光板１０の上面２１から出射される光の輝度であり、図１０の横軸は、光源１１の光軸からの距離である。図１０に示すように、光源１１の光軸からの距離が大きくなるにつれて、レンチキュラー２３の角度が４５度である場合における光の輝度よりも、レンチキュラー２３の角度が７５度である場合における光の輝度が大きくなる。レンチキュラー２３の角度が７５度である場合のコントラスト比は、レンチキュラー２３の角度が４５度である場合のコントラスト比よりも大きくなる。図８に示したように、レンチキュラー２３の角度が７０度より大きくなると、コントラスト比が１／５０００よりも大きくなる。 In FIG. 10, the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10 when the angle of the lenticular 23 is 45 degrees and the upper surface 21 of the light guide plate 10 when the angle of the lenticular 23 is 75 degrees The luminance distribution of the emitted light is shown. The vertical axis in FIG. 10 is the brightness of light emitted from the upper surface 21 of the light guide plate 10, and the horizontal axis in FIG. 10 is the distance from the optical axis of the light source 11. As shown in FIG. 10, as the distance from the optical axis of the light source 11 increases, the light intensity in the case where the angle of the lenticular 23 is 75 degrees than the light intensity in the case where the angle of the lenticular 23 is 45 degrees. The brightness is increased. The contrast ratio when the angle of the lenticular 23 is 75 degrees is larger than the contrast ratio when the angle of the lenticular 23 is 45 degrees. As shown in FIG. 8, when the angle of the lenticular 23 becomes larger than 70 degrees, the contrast ratio becomes larger than 1/5000.
　図１１は、導光板１０の厚みと、コントラスト比と、レンチキュラー２３の角度との関係を示す図である。図１１の縦軸は、コントラスト比であり、図１１の横軸は、レンチキュラー２３の角度である。図１１には、導光板１０の厚みが０．２ｍｍ、０．３ｍｍ、０．５ｍｍ、１．０ｍｍである場合のコントラスト比が示されている。導光板１０の厚みは、レンチキュラー２３の高さを除外している。すなわち、レンチキュラー２３の部分を除いた導光板１０の厚みが０．２ｍｍ、０．３ｍｍ、０．５ｍｍ、１．０ｍｍである。図１１では、コントラスト比を対数で示している。図１１に示すように、レンチキュラー２３の角度が３０度以上７５度以下の範囲において、レンチキュラー２３の角度が１５度である場合と比較して、コントラスト比が向上している。このように、導光板１０の厚みが０．２ｍｍ以上１．０ｍｍ以下である場合、レンチキュラー２３の角度を３０度以上７５度以下とすることにより、レンチキュラー２３の角度が１５度である場合と比較して、コントラスト比が向上する。 FIG. 11 is a view showing the relationship between the thickness of the light guide plate 10, the contrast ratio, and the angle of the lenticular 23. As shown in FIG. The vertical axis in FIG. 11 is the contrast ratio, and the horizontal axis in FIG. 11 is the angle of the lenticular 23. FIG. 11 shows the contrast ratios when the thickness of the light guide plate 10 is 0.2 mm, 0.3 mm, 0.5 mm, and 1.0 mm. The thickness of the light guide plate 10 excludes the height of the lenticular 23. That is, the thickness of the light guide plate 10 excluding the portion of the lenticular 23 is 0.2 mm, 0.3 mm, 0.5 mm, and 1.0 mm. In FIG. 11, the contrast ratio is shown in logarithm. As shown in FIG. 11, when the angle of the lenticular 23 is in the range of 30 degrees to 75 degrees, the contrast ratio is improved as compared with the case where the angle of the lenticular 23 is 15 degrees. As described above, when the thickness of the light guide plate 10 is 0.2 mm or more and 1.0 mm or less, by setting the angle of the lenticular 23 to 30 degrees or more and 75 degrees or less, comparison with the case where the angle of the lenticular 23 is 15 degrees To improve the contrast ratio.
　液晶表示装置の画面におけるモアレは、レンチキュラー２３のピッチが狭い方が発生しにくい。また、液晶表示装置の画面におけるモアレは、モアレピッチが狭い方が視認されにくい。例えば、導光板１０の厚みが１．０ｍｍ、レンチキュラー２３の角度が６５度、レンチキュラー２３の高さが０．０１２ｍｍ、レンチキュラー２３のピッチが０．０４２ｍｍ、曲率半径比率が０．０１２である場合、モアレピッチが１ｍｍ以下である。例えば、導光板１０の厚みが１．０ｍｍ、レンチキュラー２３の角度が６５度、レンチキュラー２３の高さが０．０４ｍｍ、レンチキュラー２３のピッチが０．１２６ｍｍ、曲率半径比率が０．０４である場合、モアレピッチが３ｍｍ程度である。曲率半径比率Ｒは、レンチキュラー２３の高さＨを導光板１０の厚みＴで割った値（Ｒ＝Ｈ／Ｔ）である。 Moire on the screen of the liquid crystal display device is less likely to occur when the pitch of the lenticular 23 is narrow. In addition, moire on the screen of the liquid crystal display device is less likely to be recognized when the moire pitch is narrow. For example, when the thickness of the light guide plate 10 is 1.0 mm, the angle of the lenticular 23 is 65 degrees, the height of the lenticular 23 is 0.012 mm, the pitch of the lenticular 23 is 0.042 mm, and the curvature radius ratio is 0.012. The moiré pitch is 1 mm or less. For example, when the thickness of the light guide plate 10 is 1.0 mm, the angle of the lenticular 23 is 65 degrees, the height of the lenticular 23 is 0.04 mm, the pitch of the lenticular 23 is 0.126 mm, and the curvature radius ratio is 0.04. The moiré pitch is about 3 mm. The curvature radius ratio R is a value (R = H / T) obtained by dividing the height H of the lenticular 23 by the thickness T of the light guide plate 10.
　図１２Ａに示すように、導光板１０の入光面２０側に複数の光源１１を配置してもよい。また、図１２Ｂに示すように、導光板１０の入光面２０側に複数の光源１１を配置すると共に、導光板１０の入光面２４側に複数の光源４１を配置してもよい。導光板１０の入光面２４は、導光板１０の入光面２０の反対側の面である。光源４１の構成は、光源１１の構成と同様である。入光面２０は、第１の入光面の一例である。入光面２４は、第２の入光面の一例である。光源１１は、第１の光源の一例である。光源４１は、第２の光源の一例である。光源１１は、導光板１０の入光面２０と対向する位置に配置され、光源４１は、導光板１０の入光面２４と対向する位置に配置されている。光源１１から出射された光は、導光板１０の入光面２０から導光板１０の内部に入り、光源４１から出射された光は、導光板１０の入光面２４から導光板１０の内部に入る。 As shown to FIG. 12A, you may arrange | position the several light source 11 in the light-incidence surface 20 side of the light-guide plate 10. As shown in FIG. Further, as shown in FIG. 12B, the plurality of light sources 11 may be disposed on the light incident surface 20 side of the light guide plate 10, and the plurality of light sources 41 may be disposed on the light incident surface 24 side of the light guide plate 10. The light incident surface 24 of the light guide plate 10 is the surface opposite to the light incident surface 20 of the light guide plate 10. The configuration of the light source 41 is the same as the configuration of the light source 11. The light incident surface 20 is an example of a first light incident surface. The light incident surface 24 is an example of a second light incident surface. The light source 11 is an example of a first light source. The light source 41 is an example of a second light source. The light source 11 is disposed at a position facing the light incident surface 20 of the light guide plate 10, and the light source 41 is disposed at a position facing the light incident surface 24 of the light guide plate 10. The light emitted from the light source 11 enters the inside of the light guide plate 10 from the light incident surface 20 of the light guide plate 10, and the light emitted from the light source 41 enters the light guide plate 10 from the light incident surface 24 of the light guide plate 10. enter.
　図１２Ａ及び図１２Ｂには、導光板１０の上面２１から出射される光の輝度分布が示されている。図１２Ａでは、一つの光源１１から出射された光が、導光板１０に入射されている。図１２Ｂでは、一つの光源１１及び一つの光源４１から出射された光が、導光板１０に入射されている。図１２Ｂでは、導光板１０の入光面２０及び入光面２４から光を入射することにより、導光板１０内の導光距離が短縮されている。そのため、図１２Ｂに示すように、導光板１０の上面２１から出射される光の輝度が、導光板１０の横幅方向（図１２ＢのＸ方向）に向かって広がることが抑制されている。 The luminance distribution of the light emitted from the upper surface 21 of the light guide plate 10 is shown in FIGS. 12A and 12B. In FIG. 12A, light emitted from one light source 11 is incident on the light guide plate 10. In FIG. 12B, light emitted from one light source 11 and one light source 41 is incident on the light guide plate 10. In FIG. 12B, the light guide distance in the light guide plate 10 is shortened by entering the light from the light entrance surface 20 and the light entrance surface 24 of the light guide plate 10. Therefore, as shown to FIG. 12B, it is suppressed that the brightness | luminance of the light radiate | emitted from the upper surface 21 of the light-guide plate 10 is spread toward the width direction (X direction of FIG. 12B) of the light-guide plate 10.
　例えば、図３Ａ及び図３Ｂに示す導光板１０では、複数のレンチキュラー２３が、連続して配置され、隣り合う２つのレンチキュラー２３が繋がっている例を示した。図３Ａ及び図３Ｂに示す導光板１０の構成例に限定されず、複数のレンチキュラー２３は、一定の間隔を空けて配置されてもよい。例えば、図１３Ａに示すように、複数のレンチキュラー２３のうち隣り合うレンチキュラー２３の間に平坦部（平坦面）２５を設けるようにしてもよい。図１３Ａに示す導光板１０の構成例では、複数のレンチキュラー２３が、一定の間隔を空けて、互いに平行に並んで配置されている。図１３Ａに示す導光板１０の構成例では、複数のレンチキュラー２３の曲面２３Ａ及び複数の平坦部２５によって、導光板１０の上面２１が形成されている。平坦部（平坦面）２５は、平板部３０の平面３１と同一面である。したがって、図１３Ａに示す導光板１０の構成例では、複数のレンチキュラー２３の曲面２３Ａ及び平板部３０の平面３１によって、導光板１０の上面２１が形成されている。平坦部２５は、導光板１０の下面２２と平行であってもよい。図１３Ａに示すレンチキュラー２３の角度は、例えば８０度である。導光板１０の上面２１に、複数のレンチキュラー２３を設けると共に、隣り合うレンチキュラー２３の間に平坦部２５を設けることで、レンチキュラー２３の角度が７０度より大きい場合であっても、コントラスト比を１／５０００よりも小さくすることができる。なお、図１３Ａに示すレンチキュラー２３の角度は、８０度以外であってもよく、例えば、３０度以上７０度以下であってもよいし、４５度以上６０度以下であってもよい。 For example, in the light guide plate 10 shown in FIG. 3A and FIG. 3B, a plurality of lenticulars 23 are continuously arranged, and an example in which two adjacent lenticulars 23 are connected is shown. It is not limited to the example of composition of light guide plate 10 shown in Drawing 3A and Drawing 3B, but a plurality of lenticulars 23 may be arranged at fixed intervals. For example, as shown in FIG. 13A, a flat portion (flat surface) 25 may be provided between adjacent ones of the plurality of lenticulars 23. In the configuration example of the light guide plate 10 shown in FIG. 13A, a plurality of lenticulars 23 are arranged in parallel with each other at a constant interval. In the configuration example of the light guide plate 10 shown in FIG. 13A, the upper surface 21 of the light guide plate 10 is formed by the curved surfaces 23A of the plurality of lenticulars 23 and the plurality of flat portions 25. The flat portion (flat surface) 25 is the same surface as the flat surface 31 of the flat plate portion 30. Therefore, in the configuration example of the light guide plate 10 shown in FIG. 13A, the upper surface 21 of the light guide plate 10 is formed by the curved surfaces 23A of the plurality of lenticulars 23 and the flat surfaces 31 of the flat plate portion 30. The flat portion 25 may be parallel to the lower surface 22 of the light guide plate 10. The angle of the lenticular 23 shown in FIG. 13A is, for example, 80 degrees. By providing the plurality of lenticulars 23 on the upper surface 21 of the light guide plate 10 and providing the flat portions 25 between the adjacent lenticulars 23, the contrast ratio is 1 even if the angle of the lenticulars 23 is larger than 70 degrees. It can be smaller than / 5000. The angle of the lenticular 23 shown in FIG. 13A may be other than 80 degrees, and may be, for example, 30 degrees or more and 70 degrees or less, or 45 degrees or more and 60 degrees or less.
　図１３Ｂには、平坦部２５が設けられていない導光板１０の上面２１から出射される光の輝度分布と、平坦部２５が設けられた導光板１０の上面２１から出射される光の輝度分布とが示されている。平坦部２５が設けられていない導光板１０には、複数のレンチキュラー２３が、平板部３０の平面３１に隙間なく配置されている。平坦部２５が設けられた導光板１０には、複数のレンチキュラー２３が、一定の間隔を空けて配置されている。図１３Ｂの縦軸は、導光板１０の上面２１から出射される光の輝度であり、図１３Ｂの横軸は、光源１１の光軸からの距離である。平坦部２５が設けられていない導光板１０におけるレンチキュラー２３の角度は６０度であり、平坦部２５が設けられた導光板１０におけるレンチキュラー２３の角度は８０度である。レンチキュラー２３の部分を除いた導光板１０の厚みは０．４ｍｍである。図１３Ｂに示すように、平坦部２５が設けられていない導光板１０の上面２１から出射される光の輝度分布と、平坦部２５が設けられた導光板１０の上面２１から出射される光の輝度分布とが同等である。このように、レンチキュラー２３の角度が８０度である場合であっても、導光板１０の上面２１に、複数のレンチキュラー２３を設けると共に、隣り合うレンチキュラー２３の間に平坦部２５を設けることで、導光板１０の上面２１から出射される光の輝度分布の制御を向上することができる。 In FIG. 13B, the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10 without the flat portion 25 and the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10 with the flat portion 25 provided. And are shown. In the light guide plate 10 in which the flat portion 25 is not provided, the plurality of lenticulars 23 are disposed on the flat surface 31 of the flat plate portion 30 without a gap. On the light guide plate 10 provided with the flat portion 25, a plurality of lenticulars 23 are arranged at a constant interval. The vertical axis in FIG. 13B is the brightness of light emitted from the upper surface 21 of the light guide plate 10, and the horizontal axis in FIG. 13B is the distance from the optical axis of the light source 11. The angle of the lenticular 23 in the light guide plate 10 in which the flat portion 25 is not provided is 60 degrees, and the angle of the lenticular 23 in the light guide plate 10 in which the flat portion 25 is provided is 80 degrees. The thickness of the light guide plate 10 excluding the portion of the lenticular 23 is 0.4 mm. As shown in FIG. 13B, the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10 where the flat portion 25 is not provided and the light distribution of the light emitted from the upper surface 21 of the light guide plate 10 where the flat portion 25 is provided. It is equal to the luminance distribution. As described above, even when the angle of the lenticular 23 is 80 degrees, by providing the plurality of lenticulars 23 on the upper surface 21 of the light guide plate 10 and providing the flat portion 25 between the adjacent lenticulars 23, Control of the luminance distribution of the light emitted from the upper surface 21 of the light guide plate 10 can be improved.
　図１３Ｃには、平坦部２５が設けられていない導光板１０におけるコントラスト比と、平坦部２５が設けられた導光板１０におけるコントラスト比とが示されている。レンチキュラー２３の部分を除いた導光板１０の厚みは０．４ｍｍである。導光板１０の上面２１に、複数のレンチキュラー２３を設けると共に、隣り合うレンチキュラー２３の間に平坦部２５を設けることで、レンチキュラー２３の角度が８０度の場合であっても、コントラスト比を１／５０００よりも小さくすることができることが、図１３Ｃから確認できる。平坦部２５が設けられた導光板１０について、レンチキュラー２３の部分を除いた導光板１０の厚みが０．２ｍｍ、０．３ｍｍ、０．５ｍｍ、１．０ｍｍである場合も、レンチキュラー２３の部分を除いた導光板１０の厚みが０．４ｍｍである場合と同様の効果を得ることができる。また、平坦部２５が設けられた導光板１０は、レンチキュラー２３の角度が３０度以上７０度以下の範囲において、平坦部２５が設けられていない導光板１０と同様の効果を得ることができる。すなわち、平坦部２５が設けられた導光板１０によれば、レンチキュラー２３の角度が３０度以上８０度以下の範囲において、コントラスト比が１／５０００以下であり、レンチキュラー２３の角度が４５度以上６０度以下の範囲において、コントラスト比が１／１００００付近の値になる。 FIG. 13C shows the contrast ratio in the light guide plate 10 in which the flat portion 25 is not provided and the contrast ratio in the light guide plate 10 in which the flat portion 25 is provided. The thickness of the light guide plate 10 excluding the portion of the lenticular 23 is 0.4 mm. By providing the plurality of lenticulars 23 on the upper surface 21 of the light guide plate 10 and providing the flat portions 25 between the adjacent lenticulars 23, the contrast ratio is 1/1, even when the angle of the lenticulars 23 is 80 degrees. It can be confirmed from FIG. 13C that it can be made smaller than 5000. In the light guide plate 10 provided with the flat portion 25, even when the thickness of the light guide plate 10 excluding the portion of the lenticular 23 is 0.2 mm, 0.3 mm, 0.5 mm, and 1.0 mm, the portion of the lenticular 23 is The same effect as in the case where the thickness of the removed light guide plate 10 is 0.4 mm can be obtained. Moreover, the light guide plate 10 provided with the flat portion 25 can obtain the same effect as the light guide plate 10 in which the flat portion 25 is not provided, in the range where the angle of the lenticular 23 is 30 degrees or more and 70 degrees or less. That is, according to the light guide plate 10 in which the flat portion 25 is provided, the contrast ratio is 1/5000 or less and the angle of the lenticular 23 is 45 degrees or more 60 in the range of 30 degrees or more and 80 degrees or less. The contrast ratio becomes a value near 1/10000 in the range below degree.
　レンチキュラー２３の高さ及び曲率半径を変更することにより、レンチキュラー２３の角度を調整してもよい。レンチキュラー２３の高さを一定にして、レンチキュラー２３の曲率半径を変更することにより、レンチキュラー２３の角度を調整してもよい。レンチキュラー２３の曲率半径を一定にして、レンチキュラー２３の高さを変更することにより、レンチキュラー２３の角度を調整してもよい。 The angle of the lenticular 23 may be adjusted by changing the height and the radius of curvature of the lenticular 23. The angle of the lenticular 23 may be adjusted by changing the radius of curvature of the lenticular 23 while keeping the height of the lenticular 23 constant. The angle of the lenticular 23 may be adjusted by changing the height of the lenticular 23 while keeping the curvature radius of the lenticular 23 constant.
　例えば、図３Ａ及び図３Ｂに示す導光板１０では、複数のレンチキュラー２３が、平板部３０の平面３１に設けられ、各レンチキュラー２３が、平板部３０の平面３１の法線方向から見て、導光板１０の入光面２０に対して垂直方向に延在する凸条である例を示した。図３Ａ及び図３Ｂに示す導光板１０の構成例に限定されず、図１４Ａに示すように、複数のレンチキュラー３３が、平板部３０の平面３２に設けられ、各レンチキュラー３３が、平板部３０の平面３２の法線方向から見て、導光板１０の入光面２０に対して垂直方向に延在する凸条であってもよい。平板部３０の平面３２は、平板部３０の平面３１の反対側の面である。複数のレンチキュラー３３は、曲面３３Ａを有している。曲面３３Ａは、平面３２に対して傾斜している。したがって、レンチキュラー３３は、平面３２に対して傾斜する傾斜面を有する。 For example, in the light guide plate 10 shown in FIGS. 3A and 3B, the plurality of lenticulars 23 are provided on the flat surface 31 of the flat plate portion 30, and each lenticular 23 is guided as viewed from the normal direction of the flat surface 31 of the flat plate portion 30. An example is shown in which the ridges extend in the direction perpendicular to the light incident surface 20 of the light plate 10. It is not limited to the example of composition of light guide plate 10 shown in Drawing 3A and Drawing 3B, As shown in Drawing 14A, a plurality of lenticulars 33 are provided in plane 32 of flat plate part 30, and each lenticular 33 is It may be a ridge extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 as viewed in the normal direction of the plane 32. The flat surface 32 of the flat plate portion 30 is a surface opposite to the flat surface 31 of the flat plate portion 30. The plurality of lenticulars 33 have curved surfaces 33A. The curved surface 33A is inclined with respect to the plane 32. Therefore, the lenticular 33 has an inclined surface which is inclined with respect to the plane 32.
　図１４Ａに示す導光板１０の構成例では、平板部３０の平面によって、導光板１０の上面２１が形成されており、導光板１０の上面２１から光が出射される。また、図１４Ａに示す導光板１０の構成例では、複数のレンチキュラー３３の曲面３３Ａによって、導光板１０の下面２２が形成されている。レンチキュラー３３の角度は、平板部３０の平面３２と、レンチキュラー３３の端部における曲面３３Ａの接線Ｌ２とでなす角度（θ）である（図１４Ｂ参照）。導光板１０の下面２２側にレンチキュラー３３を設けた場合であっても、導光板１０の上面２１側にレンチキュラー２３を設けた場合と同様に、導光板１０の上面２１から出射される光の輝度の広がりを抑制することができる。また、導光板１０の上面２１側にレンチキュラー２３を設けると共に、導光板１０の下面２２側にレンチキュラー３３を設けてもよい。また、複数のレンチキュラー３３が、一定の間隔を空けて平板部３０の平面３２に配置されてもよい。 In the configuration example of the light guide plate 10 shown in FIG. 14A, the upper surface 21 of the light guide plate 10 is formed by the flat surface of the flat plate portion 30, and light is emitted from the upper surface 21 of the light guide plate 10. Further, in the configuration example of the light guide plate 10 shown in FIG. 14A, the lower surface 22 of the light guide plate 10 is formed by the curved surfaces 33A of the plurality of lenticulars 33. The angle of the lenticular 33 is an angle (θ) formed by the flat surface 32 of the flat plate portion 30 and the tangent L2 of the curved surface 33A at the end of the lenticular 33 (see FIG. 14B). Even when the lenticular 33 is provided on the lower surface 22 side of the light guide plate 10, the brightness of light emitted from the upper surface 21 of the light guide plate 10 is the same as when the lenticular 23 is provided on the upper surface 21 side of the light guide plate 10. It is possible to suppress the spread of Further, the lenticular 23 may be provided on the upper surface 21 side of the light guide plate 10 and the lenticular 33 may be provided on the lower surface 22 side of the light guide plate 10. In addition, a plurality of lenticulars 33 may be disposed on the flat surface 32 of the flat plate portion 30 with a predetermined interval.
　例えば、図３Ａ及び図３Ｂに示す導光板１０では、レンチキュラー２３が、平板部３０の平面３１に設けられた凸条である例を示した。図３Ａ及び図３Ｂに示す導光板１０の構成例に限定されず、図１５及び図１６Ａに示すように、複数のレンチキュラー２３が、平板部３０の平面３１に設けられ、各レンチキュラー２３が、平板部３０の平面３１の法線方向から見て、導光板１０の入光面２０に対して垂直方向に延在する凹条であってもよい。複数のレンチキュラー２３は、曲面２３Ｂを有している。曲面２３Ｂは、平面３１に対して傾斜している。したがって、レンチキュラー２３は、平面３１に対して傾斜する傾斜面を有する。複数のレンチキュラー２３の曲面２３Ｂによって、導光板１０の上面２１が形成されている。レンチキュラー２３の曲面２３Ｂが、平板部３０の平面３１の法線方向に向かって平板部３０の平面３１よりも凹んでいる。 For example, in the light guide plate 10 shown in FIG. 3A and FIG. 3B, the example in which the lenticular 23 is a convex stripe provided on the plane 31 of the flat plate portion 30 is shown. The present invention is not limited to the configuration example of the light guide plate 10 shown in FIGS. 3A and 3B, but as shown in FIGS. 15 and 16A, a plurality of lenticulars 23 are provided on the flat surface 31 of the flat plate portion 30, and each lenticular 23 is flat It may be a concave extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 as viewed in the normal direction of the plane 31 of the portion 30. The plurality of lenticulars 23 have curved surfaces 23B. The curved surface 23 B is inclined with respect to the plane 31. Therefore, the lenticular 23 has an inclined surface which is inclined with respect to the plane 31. The upper surface 21 of the light guide plate 10 is formed by the curved surfaces 23B of the plurality of lenticulars 23. The curved surface 23 B of the lenticular 23 is recessed from the flat surface 31 of the flat plate portion 30 in the normal direction of the flat surface 31 of the flat plate portion 30.
　導光板１０がレンチキュラー２３を備えることにより、導光板１０の上面２１から出射される光の分布が制御され、導光板１０の上面２１から出射される光の輝度分布を制御できる。複数のレンチキュラー２３は、互いに平行に並んで配置されている。図１５、図１６Ａ及び図１６Ｂに示す導光板１０の構成例では、複数のレンチキュラー２３が、連続して配置されており、隣り合う２つのレンチキュラー２３同士が繋がっている。したがって、図１５、図１６Ａ及び図１６Ｂに示す導光板１０の構成例では、複数のレンチキュラー２３が、平板部３０の平面３１に隙間なく配置されている。図１５、図１６Ａ及び図１６Ｂに示す導光板１０の構成例では、レンチキュラー２３の幅と、レンチキュラー２３のピッチとが同一である。レンチキュラー２３の角度は、平板部３０の平面３１と、レンチキュラー２３の端部における曲面２３Ｂの接線Ｌ３とでなす角度（θ）である（図１６Ｂ参照）。 By providing the light guide plate 10 with the lenticular 23, the distribution of light emitted from the upper surface 21 of the light guide plate 10 can be controlled, and the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10 can be controlled. The plurality of lenticulars 23 are arranged parallel to one another. In the configuration example of the light guide plate 10 shown in FIG. 15, FIG. 16A and FIG. 16B, a plurality of lenticulars 23 are continuously arranged, and two adjacent lenticulars 23 are connected. Therefore, in the configuration example of the light guide plate 10 shown in FIG. 15, FIG. 16A and FIG. 16B, the plurality of lenticulars 23 are disposed on the flat surface 31 of the flat plate portion 30 without a gap. In the configuration example of the light guide plate 10 shown in FIGS. 15, 16A and 16B, the width of the lenticular 23 and the pitch of the lenticular 23 are the same. The angle of the lenticular 23 is an angle (θ) formed by the flat surface 31 of the flat plate portion 30 and the tangent L3 of the curved surface 23B at the end of the lenticular 23 (see FIG. 16B).
　複数のレンチキュラー２３が凹条であっても、レンチキュラー２３の角度が３０度以上７０度以下の範囲において、コントラスト比を１／５０００以下にすることが可能である。また、複数のレンチキュラー２３が凹条であっても、レンチキュラー２３の角度が４５度以上６０度以下の範囲において、コントラスト比を１／１００００付近の値にすることが可能である。また、複数のレンチキュラー２３が凹条であっても、レンチキュラー２３の部分を除いた導光板１０の厚みが０．２ｍｍ以上１．０ｍｍ以下である場合、レンチキュラー２３の角度を３０度以上７５度以下とすることにより、コントラスト比を向上することが可能である。 Even if the plurality of lenticulars 23 are concaves, it is possible to set the contrast ratio to 1/5000 or less when the angle of the lenticulars 23 is in the range of 30 degrees to 70 degrees. Further, even if the plurality of lenticulars 23 are concave streaks, the contrast ratio can be set to a value near 1/10000 in the range where the angle of the lenticulars 23 is 45 degrees or more and 60 degrees or less. Further, even if the plurality of lenticulars 23 are concave stripes, when the thickness of the light guide plate 10 excluding the portion of the lenticulars 23 is 0.2 mm or more and 1.0 mm or less, the angle of the lenticular 23 is 30 degrees or more and 75 degrees or less By doing this, it is possible to improve the contrast ratio.
　図１５、図１６Ａ及び図１６Ｂに示す導光板１０の構成例に限定されず、複数のレンチキュラー２３は、一定の間隔を空けて配置されてもよい。例えば、図１７に示すように、複数のレンチキュラー２３のうち隣り合うレンチキュラー２３の間に平坦部２５を設けるようにしてもよい。図１７に示す導光板１０の構成例では、複数のレンチキュラー２３が、一定の間隔を空けて、互いに平行に並んで配置されている。図１７に示す導光板１０の構成例では、複数のレンチキュラー２３の曲面２３Ｂ及び複数の平坦部２５によって、導光板１０の上面２１が形成されている。平坦部（平坦面）２５は、平板部３０の平面３１と同一面である。したがって、図１７に示す導光板１０の構成例では、複数のレンチキュラー２３の曲面２３Ｂ及び平板部３０の平面３１によって、導光板１０の上面２１が形成されている。平坦部２５は、導光板１０の下面２２と平行であってもよい。図１７に示すレンチキュラー２３の角度は、例えば８０度である。導光板１０の上面２１に、複数のレンチキュラー２３を設けると共に、隣り合うレンチキュラー２３の間に平坦部２５を設けることで、レンチキュラー２３の角度が７０度より大きい場合であっても、コントラスト比を１／５０００よりも小さくすることができる。なお、図１７に示すレンチキュラー２３の角度は、８０度以外であってもよく、例えば３０度以上７０度以下であってもよいし、４５度以上６０度以下であってもよい。 It is not limited to the example of composition of light guide plate 10 shown in Drawing 15, Drawing 16A, and Drawing 16B, and a plurality of lenticulars 23 may be arranged at fixed intervals. For example, as shown in FIG. 17, flat portions 25 may be provided between adjacent ones of the plurality of lenticulars 23. In the configuration example of the light guide plate 10 shown in FIG. 17, a plurality of lenticulars 23 are arranged in parallel with each other at a constant interval. In the configuration example of the light guide plate 10 shown in FIG. 17, the upper surface 21 of the light guide plate 10 is formed by the curved surfaces 23 B of the plurality of lenticulars 23 and the plurality of flat portions 25. The flat portion (flat surface) 25 is the same surface as the flat surface 31 of the flat plate portion 30. Therefore, in the configuration example of the light guide plate 10 shown in FIG. 17, the upper surface 21 of the light guide plate 10 is formed by the curved surfaces 23 B of the plurality of lenticulars 23 and the flat surfaces 31 of the flat plate portion 30. The flat portion 25 may be parallel to the lower surface 22 of the light guide plate 10. The angle of the lenticular 23 shown in FIG. 17 is, for example, 80 degrees. By providing the plurality of lenticulars 23 on the upper surface 21 of the light guide plate 10 and providing the flat portions 25 between the adjacent lenticulars 23, the contrast ratio is 1 even if the angle of the lenticulars 23 is larger than 70 degrees. It can be smaller than / 5000. The angle of the lenticular 23 shown in FIG. 17 may be other than 80 degrees, and may be, for example, 30 degrees or more and 70 degrees or less, or 45 degrees or more and 60 degrees or less.
　また、図１８に示すように、複数のレンチキュラー２３が、平板部３０の平面３１に設けられ、複数のレンチキュラー２３のうちの一部が凸条であり、複数のレンチキュラー２３のうちの他の一部が凹条であってもよい。図１８に示すように、複数の凸条が隣り合うようにして配置され、複数の凹条が隣り合うようにして配置されている。図１８に示す導光板１０の構成例では、複数のレンチキュラー２３が、平板部３０の平面３１に隙間なく配置されている。すなわち、複数の凸条及び複数の凹条が、平板部３０の平面３１に隙間なく配置されている。図１８に示す導光板１０の構成例に限定されず、例えば、一つ以上の凸条と一つ以上の凹条とが交互に平板部３０の平面３１に配置されてもよい。図１３Ａ及び図１７に示す導光板１０の構成例と同様に、複数のレンチキュラー２３のうち隣り合うレンチキュラー２３の間に平坦部２５を設けることにより、複数の凸条及び複数の凹条が、一定の間隔を空けて平板部３０の平面３１に配置されてもよい。複数の凸条が、一定の間隔を空けて平板部３０の平面３１に配置され、複数の凹条が、隙間なく平板部３０の平面３１に配置されてもよい。複数の凸条が、隙間なく平板部３０の平面３１に配置され、複数の凹条が、一定の間隔を空けて平板部３０の平面３１に配置されてもよい。また、複数の凸条及び複数の凹条が、一定の間隔を空けて平板部３０の平面３２に配置されてもよい。複数の凸条が、一定の間隔を空けて平板部３０の平面３２に配置され、複数の凹条が、隙間なく平板部３０の平面３２に配置されてもよい。複数の凸条が、隙間なく平板部３０の平面３２に配置され、複数の凹条が、一定の間隔を空けて平板部３０の平面３２に配置されてもよい。 Further, as shown in FIG. 18, a plurality of lenticulars 23 are provided on the flat surface 31 of the flat plate portion 30, and a part of the plurality of lenticulars 23 is a convex stripe, and another one of the plurality of lenticulars 23 is The part may be concave. As shown in FIG. 18, a plurality of ridges are arranged to be adjacent to each other, and a plurality of grooves are arranged to be adjacent to each other. In the configuration example of the light guide plate 10 shown in FIG. 18, the plurality of lenticulars 23 are disposed on the flat surface 31 of the flat plate portion 30 without a gap. That is, the plurality of convex lines and the plurality of concave lines are disposed on the flat surface 31 of the flat plate portion 30 without a gap. The present invention is not limited to the configuration example of the light guide plate 10 shown in FIG. 18. For example, one or more convex lines and one or more concave lines may be alternately disposed on the flat surface 31 of the flat plate portion 30. Similar to the configuration example of the light guide plate 10 shown in FIGS. 13A and 17, by providing the flat portion 25 between the adjacent ones of the plurality of lenticulars 23, the plurality of convex stripes and the plurality of concave stripes are constant. And may be disposed on the flat surface 31 of the flat plate portion 30 with a space between A plurality of ridges may be disposed on the flat surface 31 of the flat plate portion 30 at a constant interval, and a plurality of concave stripes may be disposed on the flat surface 31 of the flat plate portion 30 without a gap. A plurality of ridges may be disposed on the flat surface 31 of the flat plate portion 30 without a gap, and a plurality of concave stripes may be disposed on the flat surface 31 of the flat plate portion 30 at a constant interval. In addition, a plurality of convex lines and a plurality of concave lines may be disposed on the flat surface 32 of the flat plate portion 30 at a constant interval. A plurality of ridges may be disposed on the flat surface 32 of the flat plate portion 30 at a constant interval, and a plurality of concave stripes may be disposed on the flat surface 32 of the flat plate portion 30 without a gap. A plurality of ridges may be disposed on the flat surface 32 of the flat plate portion 30 without a gap, and a plurality of concave stripes may be disposed on the flat surface 32 of the flat plate portion 30 at regular intervals.
　以上説明した実施形態の導光板１０によれば、レンチキュラー２３の角度を３０度以上７０度以下とすることにより、導光板１０の上面２１から出射される光の輝度の広がりを抑制することができるため、コントラスト比が向上する。導光板１０の上面２１から出射される光の輝度の広がりを抑制することができるため、ローカルディミング制御において、狭い幅の領域における発光輝度の制御が容易となる。また、実施形態の導光板１０によれば、レンチキュラー２３の角度を４５度以上６０度以下とすることにより、コントラスト比が更に向上する。そのため、このような導光板１０を備える面光源装置１をバックライトとして搭載することで、コントラスト比が向上した液晶表示装置を提供することができる。 According to the light guide plate 10 of the embodiment described above, the spread of the luminance of light emitted from the upper surface 21 of the light guide plate 10 can be suppressed by setting the angle of the lenticular 23 to 30 degrees or more and 70 degrees or less. Therefore, the contrast ratio is improved. Since the spread of the luminance of the light emitted from the upper surface 21 of the light guide plate 10 can be suppressed, the control of the light emission luminance in the narrow width area becomes easy in the local dimming control. Further, according to the light guide plate 10 of the embodiment, the contrast ratio is further improved by setting the angle of the lenticular 23 to 45 degrees or more and 60 degrees or less. Therefore, by mounting the surface light source device 1 including such a light guide plate 10 as a backlight, it is possible to provide a liquid crystal display device having an improved contrast ratio.
　図１９Ａ及び図１９Ｂは、実施形態に係る導光板１０を示す図である。図１９Ａ及び図１９Ｂに示す導光板１０の構成例では、導光板１０が、平板部３０の平面３１に設けられた複数のレンチキュラー２３を備え、各レンチキュラー２３が、曲面２３Ａ及び平坦面５１Ａを有する。各レンチキュラー２３は、平板部３０の平面３１の法線方向から見て、導光板１０の入光面２０に対して垂直方向に延在する凸条である。曲面２３Ａ及び平坦面５１Ａは、平面３１に対して傾斜している。したがって、レンチキュラー２３は平面３１に対して傾斜する傾斜面を有する。 19A and 19B are diagrams showing the light guide plate 10 according to the embodiment. In the configuration example of the light guide plate 10 shown in FIGS. 19A and 19B, the light guide plate 10 includes a plurality of lenticulars 23 provided on the flat surface 31 of the flat plate portion 30, and each lenticular 23 has a curved surface 23A and a flat surface 51A. . Each lenticular 23 is a ridge extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 when viewed in the normal direction of the flat surface 31 of the flat plate portion 30. The curved surface 23A and the flat surface 51A are inclined with respect to the plane 31. Therefore, the lenticular 23 has an inclined surface which is inclined with respect to the plane 31.
　図１９Ａに示す導光板１０の構成例では、複数のレンチキュラー２３が、連続して配置されており、隣り合うレンチキュラー２３同士が繋がっている。隣り合う２つのレンチキュラー２３における向かい合う２つの平坦面５１Ａが互いに接続されている。したがって、複数のレンチキュラー２３が、平板部３０の平面３１に隙間なく配置されている。図１９Ｂに示す導光板１０の構成例では、隣り合うレンチキュラー２３の間に平坦部２５が設けられている。平坦部２５が、隣り合うレンチキュラー２３の各平坦面５１Ａに接続されている。したがって、複数のレンチキュラー２３が、一定の間隔を空けて、互いに平行に並んで配置されている。 In the configuration example of the light guide plate 10 shown in FIG. 19A, a plurality of lenticulars 23 are continuously arranged, and adjacent ones of the lenticulars 23 are connected. Two facing flat surfaces 51A of two adjacent lenticulars 23 are connected to each other. Therefore, the plurality of lenticulars 23 are disposed on the flat surface 31 of the flat plate portion 30 without a gap. In the configuration example of the light guide plate 10 shown in FIG. 19B, the flat portion 25 is provided between the adjacent lenticulars 23. The flat portions 25 are connected to the flat surfaces 51A of the adjacent lenticulars 23. Therefore, a plurality of lenticulars 23 are arranged in parallel with each other at a constant interval.
　図１９Ｃ～図１９Ｅは、実施形態に係る導光板１０を示す図である。図１９Ｃ～図１９Ｅに示す導光板１０の構成例では、レンチキュラー２３の角度が６０度であるが、レンチキュラー２３の角度は６０度以外であってもよい。レンチキュラー２３の角度は、例えば、３０度以上８０度以下であってもよいし、３０度以上７０度以下であってもよいし、４５度以上６０度以下であってもよい。レンチキュラー２３の角度は、平板部３０の平面３１と、レンチキュラー２３の端部における平坦面５１Ａとでなす角度（θ）である。 19C to 19E are views showing the light guide plate 10 according to the embodiment. In the configuration example of the light guide plate 10 shown in FIGS. 19C to 19E, the angle of the lenticular 23 is 60 degrees, but the angle of the lenticular 23 may be other than 60 degrees. The angle of the lenticular 23 may be, for example, 30 degrees or more and 80 degrees or less, 30 degrees or more and 70 degrees or less, or 45 degrees or more and 60 degrees or less. The angle of the lenticular 23 is an angle (θ) formed by the flat surface 31 of the flat plate portion 30 and the flat surface 51 A at the end of the lenticular 23.
　図１９Ｃ～図１９Ｅに示すように、レンチキュラー２３は、導光板１０の入光面２０の法線方向から見て、台形状部分５２Ａと、台形状部分５２Ａの上底に接する円弧形状部分５３Ａとを含む。台形状部分５２Ａの上底の長さは、台形状部分５２Ａの下底の長さよりも短い。台形状部分５２Ａが平板部３０の平面３１に接しており、円弧形状部分５３Ａが平板部３０の平面３１から離間している。図１９Ｃに示す導光板１０の構成例では、台形状部分５２Ａの高さが、台形状部分５２Ａの高さ及び円弧形状部分５３Ａの高さの合計値の５０％である。図１９Ｄに示す導光板１０の構成例では、台形状部分５２Ａの高さが、台形状部分５２Ａの高さ及び円弧形状部分５３Ａの高さの合計値の８０％である。図１９Ｅに示す導光板１０の構成例では、台形状部分５２Ａの高さが、台形状部分５２Ａの高さ及び円弧形状部分５３Ａの高さの合計値の９０％である。台形状部分５２Ａの高さ及び円弧形状部分５３Ａの高さの合計値に対する台形状部分５２Ａの高さの割合は、５０％、８０％及び９０％に限定されない。台形状部分５２Ａの高さ及び円弧形状部分５３Ａの高さの合計値に対する台形状部分５２Ａの高さの割合は、０％以上１００％以下であってもよい。 As shown in FIGS. 19C to 19E, when viewed from the normal direction of the light incident surface 20 of the light guide plate 10, the lenticular 23 has a trapezoidal portion 52A and an arc-shaped portion 53A contacting the upper bottom of the trapezoidal portion 52A. including. The length of the upper base of the trapezoidal portion 52A is shorter than the length of the lower base of the trapezoidal portion 52A. The trapezoidal portion 52A is in contact with the flat surface 31 of the flat plate portion 30, and the arc-shaped portion 53A is separated from the flat surface 31 of the flat plate portion 30. In the configuration example of the light guide plate 10 shown in FIG. 19C, the height of the trapezoidal portion 52A is 50% of the total value of the height of the trapezoidal portion 52A and the height of the arc-shaped portion 53A. In the configuration example of the light guide plate 10 shown in FIG. 19D, the height of the trapezoidal portion 52A is 80% of the total value of the height of the trapezoidal portion 52A and the height of the arc-shaped portion 53A. In the configuration example of the light guide plate 10 shown in FIG. 19E, the height of the trapezoidal portion 52A is 90% of the total value of the height of the trapezoidal portion 52A and the height of the arc-shaped portion 53A. The ratio of the height of the trapezoidal portion 52A to the sum of the height of the trapezoidal portion 52A and the height of the arc-shaped portion 53A is not limited to 50%, 80% and 90%. The ratio of the height of the trapezoidal portion 52A to the total value of the height of the trapezoidal portion 52A and the height of the arc-shaped portion 53A may be 0% or more and 100% or less.
　図２０Ａには、レンチキュラー２３の角度が６０度である場合における導光板１０の上面２１から出射される光の輝度分布が示されている。図２０Ａの縦軸は、導光板１０の上面２１から出射される光の輝度であり、図２０Ａの横軸は、光源１１の光軸からの距離である。図２０Ａには、台形状部分５２Ａの高さ及び円弧形状部分５３Ａの高さの合計値に対する台形状部分５２Ａの高さの割合が、０％、５０％、８０％及び９０％である場合の光の輝度分布が示されている。台形状部分５２Ａの高さ及び円弧形状部分５３Ａの高さの合計値に対する台形状部分５２Ａの高さの割合が０％である場合、レンチキュラー２３は、円弧形状部分５３Ａを有するが、台形状部分５２Ａを有しない。したがって、台形状部分５２Ａの高さ及び円弧形状部分５３Ａの高さの合計値に対する台形状部分５２Ａの高さの割合が０％である場合、レンチキュラー２３は、曲面２３Ａを有するが、平坦面５１Ａを有しない。 FIG. 20A shows the luminance distribution of the light emitted from the upper surface 21 of the light guide plate 10 when the angle of the lenticular 23 is 60 degrees. The vertical axis in FIG. 20A is the brightness of light emitted from the upper surface 21 of the light guide plate 10, and the horizontal axis in FIG. 20A is the distance from the optical axis of the light source 11. In FIG. 20A, the ratio of the height of trapezoidal portion 52A to the total value of the height of trapezoidal portion 52A and the height of arc-shaped portion 53A is 0%, 50%, 80% and 90%. The luminance distribution of the light is shown. When the ratio of the height of the trapezoidal portion 52A to the total value of the height of the trapezoidal portion 52A and the height of the circular arc portion 53A is 0%, the lenticular 23 has the circular arc portion 53A, but the trapezoidal portion It does not have 52A. Therefore, when the ratio of the height of the trapezoidal portion 52A to the total value of the height of the trapezoidal portion 52A and the height of the arc-shaped portion 53A is 0%, the lenticular 23 has a curved surface 23A, but the flat surface 51A. Do not have
　図２０Ａから分かるように、導光板１０の上面２１から出射される光の輝度分布について、レンチキュラー２３が曲面２３Ａのみを有する場合と、レンチキュラー２３が曲面２３Ａ及び平坦面５１Ａを有する場合との間で差が殆どない。このように、レンチキュラー２３が曲面２３Ａ及び平坦面５１Ａを有する場合、レンチキュラー２３が曲面２３Ａのみを有する場合と同様の効果を得ることができる。また、レンチキュラー２３の角度が３０度以上８０度以下であり、かつ、レンチキュラー２３が曲面２３Ａ及び平坦面５１Ａを有する場合についても、レンチキュラー２３が曲面２３Ａのみを有する場合と同様の効果を得ることができる。 As can be seen from FIG. 20A, regarding the luminance distribution of light emitted from the upper surface 21 of the light guide plate 10, between the case where the lenticular 23 has only the curved surface 23A and the case where the lenticular 23 has the curved surface 23A and the flat surface 51A. There is almost no difference. As described above, when the lenticular 23 has the curved surface 23A and the flat surface 51A, the same effect as that when the lenticular 23 has only the curved surface 23A can be obtained. In addition, also in the case where the angle of the lenticular 23 is 30 degrees or more and 80 degrees or less and the lenticular 23 has the curved surface 23A and the flat surface 51A, the same effect as the case where the lenticular 23 has only the curved surface 23A can be obtained. it can.
　図２０Ｂには、レンチキュラー２３の角度が６０度である場合のコントラスト比が示されている。図２０Ｂには、台形状部分５２Ａの高さ及び円弧形状部分５３Ａの高さの合計値に対する台形状部分５２Ａの高さの割合が、０％、５０％、８０％及び９０％である場合のコントラスト比が示されている。図２０Ｂから分かるように、コントラスト比について、レンチキュラー２３が曲面２３Ａのみを有する場合と、レンチキュラー２３が曲面２３Ａ及び平坦面５１Ａを有する場合との間で差が殆どない。このように、レンチキュラー２３が曲面２３Ａ及び平坦面５１Ａを有する場合、レンチキュラー２３が曲面２３Ａのみを有する場合と同様の効果を得ることができる。したがって、レンチキュラー２３の角度が３０度以上８０度以下であり、かつ、レンチキュラー２３が曲面２３Ａ及び平坦面５１Ａを有することにより、コントラスト比を向上することができる。 FIG. 20B shows the contrast ratio when the angle of the lenticular 23 is 60 degrees. In FIG. 20B, the ratio of the height of trapezoidal portion 52A to the total value of the height of trapezoidal portion 52A and the height of arc-shaped portion 53A is 0%, 50%, 80% and 90%. The contrast ratio is shown. As can be seen from FIG. 20B, there is almost no difference in contrast ratio between the case where the lenticular 23 has only the curved surface 23A and the case where the lenticular 23 has the curved surface 23A and the flat surface 51A. As described above, when the lenticular 23 has the curved surface 23A and the flat surface 51A, the same effect as that when the lenticular 23 has only the curved surface 23A can be obtained. Therefore, the contrast ratio can be improved by setting the angle of the lenticular 23 to 30 degrees or more and 80 degrees or less, and by the lenticular 23 having the curved surface 23A and the flat surface 51A.
　図２１Ａ及び図２１Ｂは、実施形態に係る導光板１０を示す図である。図２１Ａ及び図２１Ｂに示す導光板１０の構成例では、導光板１０が、平板部３０の平面３１に設けられた複数のレンチキュラー２３を備え、各レンチキュラー２３が、曲面２３Ｂ及び平坦面５１Ｂを有する。各レンチキュラー２３は、平板部３０の平面３１の法線方向から見て、導光板１０の入光面２０に対して垂直方向に延在する凹条である。曲面２３Ｂ及び平坦面５１Ｂは、平面３１に対して傾斜している。したがって、レンチキュラー２３は平面３１に対して傾斜する傾斜面を有する。 21A and 21B are diagrams showing the light guide plate 10 according to the embodiment. In the configuration example of the light guide plate 10 shown in FIGS. 21A and 21B, the light guide plate 10 includes a plurality of lenticulars 23 provided on the flat surface 31 of the flat plate portion 30, and each lenticular 23 has a curved surface 23B and a flat surface 51B. . Each lenticular 23 is a concave extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 as viewed in the normal direction of the flat surface 31 of the flat plate portion 30. The curved surface 23 B and the flat surface 51 B are inclined with respect to the plane 31. Therefore, the lenticular 23 has an inclined surface which is inclined with respect to the plane 31.
　図２１Ａに示す導光板１０の構成例では、複数のレンチキュラー２３が、連続して配置されており、隣り合うレンチキュラー２３同士が繋がっている。隣り合う２つのレンチキュラー２３における２つの平坦面５１Ｂが互いに接続されている。したがって、複数のレンチキュラー２３が、平板部３０の平面３１に隙間なく配置されている。図２１Ｂに示す導光板１０の構成例では、隣り合うレンチキュラー２３の間に平坦部２５が設けられている。平坦部２５が、隣り合うレンチキュラー２３の各平坦面５１Ｂに接続されている。したがって、複数のレンチキュラー２３が、一定の間隔を空けて、互いに平行に並んで配置されている。 In the configuration example of the light guide plate 10 shown in FIG. 21A, a plurality of lenticulars 23 are continuously arranged, and adjacent ones of the lenticulars 23 are connected. Two flat surfaces 51B of two adjacent lenticulars 23 are connected to each other. Therefore, the plurality of lenticulars 23 are disposed on the flat surface 31 of the flat plate portion 30 without a gap. In the configuration example of the light guide plate 10 shown in FIG. 21B, the flat portion 25 is provided between the adjacent lenticulars 23. The flat portions 25 are connected to the flat surfaces 51B of the adjacent lenticulars 23. Therefore, a plurality of lenticulars 23 are arranged in parallel with each other at a constant interval.
　図２１Ｃは、実施形態に係る導光板１０を示す図である。図２１Ｃに示す導光板１０の構成例では、レンチキュラー２３の角度が６０度であるが、レンチキュラー２３の角度は６０度以外であってもよい。レンチキュラー２３の角度は、例えば、３０度以上８０度以下であってもよいし、３０度以上７０度以下であってもよいし、４５度以上６０度以下であってもよい。レンチキュラー２３の角度は、平板部３０の平面３１と、レンチキュラー２３の端部における平坦面５１Ｂとでなす角度（θ）である。レンチキュラー２３の角度が３０度以上８０度以下であり、かつ、レンチキュラー２３が曲面２３Ｂ及び平坦面５１Ｂを有することにより、コントラスト比を向上することができる。 FIG. 21C is a view showing the light guide plate 10 according to the embodiment. In the configuration example of the light guide plate 10 shown in FIG. 21C, the angle of the lenticular 23 is 60 degrees, but the angle of the lenticular 23 may be other than 60 degrees. The angle of the lenticular 23 may be, for example, 30 degrees or more and 80 degrees or less, 30 degrees or more and 70 degrees or less, or 45 degrees or more and 60 degrees or less. The angle of the lenticular 23 is an angle (θ) formed by the flat surface 31 of the flat plate portion 30 and the flat surface 51 B at the end of the lenticular 23. The contrast ratio can be improved by setting the angle of the lenticular 23 to not less than 30 degrees and not more than 80 degrees and having the curved surface 23B and the flat surface 51B.
　図２１Ｃに示すように、レンチキュラー２３は、導光板１０の入光面２０の法線方向から見て、台形状部分５２Ｂと、台形状部分５２Ｂの下底に接する円弧形状部分５３Ｂとを含む。台形状部分５２Ｂの下底の長さは、台形状部分５２Ｂの上底の長さよりも短い。台形状部分５２Ｂが平板部３０の平面３１に接しており、円弧形状部分５３Ｂが平板部３０の平面３１から離間している。図２１Ｃに示す導光板１０の構成例では、台形状部分５２Ｂの高さが、台形状部分５２Ｂの高さ及び円弧形状部分５３Ｂの高さの合計値の５０％である。台形状部分５２Ｂの高さ及び円弧形状部分５３Ｂの高さの合計値に対する台形状部分５２Ｂの高さの割合は、５０％に限定されない。台形状部分５２Ｂの高さ及び円弧形状部分５３Ｂの高さの合計値に対する台形状部分５２Ｂの高さの割合は、０％以上１００％以下であってもよい。 As shown in FIG. 21C, the lenticular 23 includes a trapezoidal portion 52B and an arc-shaped portion 53B in contact with the lower bottom of the trapezoidal portion 52B when viewed in the normal direction of the light incident surface 20 of the light guide plate 10. The length of the lower base of the trapezoidal portion 52B is shorter than the length of the upper base of the trapezoidal portion 52B. The trapezoidal portion 52B is in contact with the flat surface 31 of the flat plate portion 30, and the arc-shaped portion 53B is separated from the flat surface 31 of the flat plate portion 30. In the configuration example of the light guide plate 10 shown in FIG. 21C, the height of the trapezoidal portion 52B is 50% of the total value of the height of the trapezoidal portion 52B and the height of the arc-shaped portion 53B. The ratio of the height of the trapezoidal portion 52B to the sum of the height of the trapezoidal portion 52B and the height of the arc-shaped portion 53B is not limited to 50%. The ratio of the height of the trapezoidal portion 52B to the total value of the height of the trapezoidal portion 52B and the height of the arc-shaped portion 53B may be 0% or more and 100% or less.
　図２２Ａ及び図２２Ｂは、実施形態に係る導光板１０を示す図である。図２２Ａ及び図２２Ｂに示す導光板１０の構成例では、導光板１０が、平板部３０の平面３２に設けられた複数のレンチキュラー３３を備え、各レンチキュラー３３が、曲面３３Ａ及び平坦面６１Ａを有する。各レンチキュラー３３は、平板部３０の平面３２の法線方向から見て、導光板１０の入光面２０に対して垂直方向に延在する凸条である。曲面３３Ａ及び平坦面６１Ａは、平面３２に対して傾斜している。したがって、レンチキュラー３３は平面３２に対して傾斜する傾斜面を有する。 Drawing 22A and Drawing 22B are figures showing light guide plate 10 concerning an embodiment. In the configuration example of the light guide plate 10 shown in FIGS. 22A and 22B, the light guide plate 10 includes a plurality of lenticulars 33 provided on the flat surface 32 of the flat plate portion 30, and each lenticular 33 has a curved surface 33A and a flat surface 61A. . Each of the lenticulars 33 is a ridge extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 when viewed in the normal direction of the flat surface 32 of the flat plate portion 30. The curved surface 33A and the flat surface 61A are inclined with respect to the plane 32. Therefore, the lenticule 33 has an inclined surface which is inclined with respect to the plane 32.
　図２２Ａに示す導光板１０の構成例では、複数のレンチキュラー３３が、連続して配置されており、隣り合うレンチキュラー３３同士が繋がっている。隣り合う２つのレンチキュラー３３における向かい合う２つの平坦面６１Ａが互いに接続されている。したがって、複数のレンチキュラー３３が、平板部３０の平面３２に隙間なく配置されている。図２２Ｂに示す導光板１０の構成例では、隣り合うレンチキュラー３３の間に平坦部２５が設けられている。平坦部２５が、隣り合うレンチキュラー３３の各平坦面６１Ａに接続されている。したがって、複数のレンチキュラー３３が、一定の間隔を空けて、互いに平行に並んで配置されている。 In the configuration example of the light guide plate 10 shown in FIG. 22A, a plurality of lenticulars 33 are continuously arranged, and adjacent ones of the lenticulars 33 are connected. Two facing flat surfaces 61A of two adjacent lenticulars 33 are connected to each other. Therefore, the plurality of lenticulars 33 are disposed on the flat surface 32 of the flat plate portion 30 without any gap. In the configuration example of the light guide plate 10 shown in FIG. 22B, the flat portion 25 is provided between the adjacent lenticulars 33. The flat portion 25 is connected to each flat surface 61A of the adjacent lenticule 33. Therefore, the plurality of lenticulars 33 are arranged in parallel with each other at a constant interval.
　図２２Ｃは、実施形態に係る導光板１０を示す図である。図２２Ｃに示す導光板１０の構成例では、レンチキュラー３３の角度が６０度であるが、レンチキュラー３３の角度は６０度以外であってもよい。レンチキュラー３３の角度は、例えば、３０度以上８０度以下であってもよいし、３０度以上７０度以下であってもよいし、４５度以上６０度以下であってもよい。レンチキュラー３３の角度は、平板部３０の平面３２と、レンチキュラー３３の端部における平坦面６１Ａとでなす角度（θ）である。レンチキュラー３３の角度が３０度以上８０度以下であり、かつ、レンチキュラー３３が曲面３３Ａ及び平坦面６１Ａを有することにより、コントラスト比を向上することができる。 Drawing 22C is a figure showing light guide plate 10 concerning an embodiment. In the configuration example of the light guide plate 10 shown in FIG. 22C, the angle of the lenticular 33 is 60 degrees, but the angle of the lenticular 33 may be other than 60 degrees. The angle of the lenticular 33 may be, for example, 30 degrees or more and 80 degrees or less, 30 degrees or more and 70 degrees or less, or 45 degrees or more and 60 degrees or less. The angle of the lenticular 33 is an angle (θ) formed by the flat surface 32 of the flat plate portion 30 and the flat surface 61A at the end of the lenticular 33. The contrast ratio can be improved by the lenticular 33 having an angle of 30 degrees or more and 80 degrees or less, and the lenticulars 33 having the curved surface 33A and the flat surface 61A.
　図２２Ｃに示すように、レンチキュラー３３は、導光板１０の入光面２０の法線方向から見て、台形状部分６２Ａと、台形状部分６２Ａの下底に接する円弧形状部分６３Ａとを含む。台形状部分６２Ａの下底の長さは、台形状部分６２Ａの上底の長さよりも短い。台形状部分６２Ａが平板部３０の平面３２に接しており、円弧形状部分６３Ａが平板部３０の平面３２から離間している。図２２Ｃに示す導光板１０の構成例では、台形状部分６２Ａの高さが、台形状部分６２Ａの高さ及び円弧形状部分６３Ａの高さの合計値の５０％である。台形状部分６２Ａの高さ及び円弧形状部分６３Ａの高さの合計値に対する台形状部分６２Ａの高さの割合は、５０％に限定されない。台形状部分６２Ａの高さ及び円弧形状部分６３Ａの高さの合計値に対する台形状部分６２Ａの高さの割合は、０％以上１００％以下であってもよい。 As shown in FIG. 22C, the lenticular 33 includes a trapezoidal portion 62A and an arc-shaped portion 63A in contact with the lower bottom of the trapezoidal portion 62A when viewed in the normal direction of the light incident surface 20 of the light guide plate 10. The length of the lower base of the trapezoidal portion 62A is shorter than the length of the upper base of the trapezoidal portion 62A. The trapezoidal portion 62A is in contact with the flat surface 32 of the flat plate portion 30, and the arc-shaped portion 63A is separated from the flat surface 32 of the flat plate portion 30. In the configuration example of the light guide plate 10 shown in FIG. 22C, the height of the trapezoidal portion 62A is 50% of the total value of the height of the trapezoidal portion 62A and the height of the arc-shaped portion 63A. The ratio of the height of the trapezoidal portion 62A to the sum of the height of the trapezoidal portion 62A and the height of the arc-shaped portion 63A is not limited to 50%. The ratio of the height of the trapezoidal portion 62A to the total value of the height of the trapezoidal portion 62A and the height of the arc-shaped portion 63A may be 0% or more and 100% or less.
　図２３Ａ及び図２３Ｂは、実施形態に係る導光板１０を示す図である。図２３Ａ及び図２３Ｂに示す導光板１０の構成例では、導光板１０が、平板部３０の平面３２に設けられた複数のレンチキュラー３３を備え、各レンチキュラー３３が、曲面３３Ｂ及び平坦面６１Ｂを有する。各レンチキュラー３３は、平板部３０の平面３２の法線方向から見て、導光板１０の入光面２０に対して垂直方向に延在する凹条である。曲面３３Ｂ及び平坦面６１Ｂは、平面３２に対して傾斜している。したがって、レンチキュラー３３は平面３２に対して傾斜する傾斜面を有する。 23A and 23B are diagrams showing the light guide plate 10 according to the embodiment. In the configuration example of the light guide plate 10 shown in FIGS. 23A and 23B, the light guide plate 10 includes a plurality of lenticulars 33 provided on the flat surface 32 of the flat plate portion 30, and each lenticular 33 has a curved surface 33B and a flat surface 61B. . Each of the lenticulars 33 is a concave extending in a direction perpendicular to the light incident surface 20 of the light guide plate 10 as viewed in the normal direction of the flat surface 32 of the flat plate portion 30. The curved surface 33 B and the flat surface 61 B are inclined with respect to the plane 32. Therefore, the lenticule 33 has an inclined surface which is inclined with respect to the plane 32.
　図２３Ａに示す導光板１０の構成例では、複数のレンチキュラー３３が、連続して配置されており、隣り合うレンチキュラー３３同士が繋がっている。隣り合う２つのレンチキュラー３３における向かい合う２つの平坦面６１Ｂが互いに接続されている。したがって、複数のレンチキュラー３３が、平板部３０の平面３２に隙間なく配置されている。図２３Ｂに示す導光板１０の構成例では、隣り合うレンチキュラー３３の間に平坦部２５が設けられている。平坦部２５が、隣り合うレンチキュラー３３の各平坦面６１Ｂに接続されている。したがって、複数のレンチキュラー３３が、一定の間隔を空けて、互いに平行に並んで配置されている。 In the configuration example of the light guide plate 10 shown in FIG. 23A, a plurality of lenticulars 33 are continuously arranged, and adjacent ones of the lenticulars 33 are connected. Two opposing flat surfaces 61B of two adjacent lenticulars 33 are connected to each other. Therefore, the plurality of lenticulars 33 are disposed on the flat surface 32 of the flat plate portion 30 without any gap. In the configuration example of the light guide plate 10 shown in FIG. 23B, the flat portion 25 is provided between the adjacent lenticulars 33. The flat portions 25 are connected to the flat surfaces 61 B of the adjacent lenticulars 33. Therefore, the plurality of lenticulars 33 are arranged in parallel with each other at a constant interval.
　図２３Ｃは、実施形態に係る導光板１０を示す図である。図２３Ｃに示す導光板１０の構成例では、レンチキュラー３３の角度が６０度であるが、レンチキュラー３３の角度は６０度以外であってもよい。レンチキュラー３３の角度は、例えば、３０度以上８０度以下であってもよいし、３０度以上７０度以下であってもよいし、４５度以上６０度以下であってもよい。レンチキュラー３３の角度は、平板部３０の平面３２と、レンチキュラー３３の端部における平坦面６１Ｂとでなす角度（θ）である。レンチキュラー３３の角度が３０度以上８０度以下であり、かつ、レンチキュラー３３が曲面３３Ｂ及び平坦面６１Ｂを有することにより、コントラスト比を向上することができる。 FIG. 23C is a view showing the light guide plate 10 according to the embodiment. In the configuration example of the light guide plate 10 shown in FIG. 23C, the angle of the lenticular 33 is 60 degrees, but the angle of the lenticular 33 may be other than 60 degrees. The angle of the lenticular 33 may be, for example, 30 degrees or more and 80 degrees or less, 30 degrees or more and 70 degrees or less, or 45 degrees or more and 60 degrees or less. The angle of the lenticular 33 is an angle (θ) formed by the flat surface 32 of the flat plate portion 30 and the flat surface 61 B at the end of the lenticular 33. The contrast ratio can be improved by the lenticular 33 having an angle of 30 degrees or more and 80 degrees or less and the lenticulars 33 having the curved surface 33B and the flat surface 61B.
　図２３Ｃに示すように、レンチキュラー３３は、導光板１０の入光面２０の法線方向から見て、台形状部分６２Ｂと、台形状部分６２Ｂの上底に接する円弧形状部分６３Ｂとを含む。台形状部分６２Ｂの上底の長さは、台形状部分６２Ｂの下底の長さよりも短い。台形状部分６２Ｂが平板部３０の平面３２に接しており、円弧形状部分６３Ｂが平板部３０の平面３２から離間している。図２３Ｃに示す導光板１０の構成例では、台形状部分６２Ｂの高さが、台形状部分６２Ｂの高さ及び円弧形状部分６３Ｂの高さの合計値の５０％である。台形状部分６２Ｂの高さ及び円弧形状部分６３Ｂの高さの合計値に対する台形状部分６２Ｂの高さの割合は、５０％に限定されない。台形状部分６２Ｂの高さ及び円弧形状部分６３Ｂの高さの合計値に対する台形状部分６２Ｂの高さの割合は、０％以上１００％以下であってもよい。 As shown in FIG. 23C, the lenticule 33 includes a trapezoidal portion 62B and an arc-shaped portion 63B in contact with the upper bottom of the trapezoidal portion 62B when viewed in the normal direction of the light incident surface 20 of the light guide plate 10. The length of the upper base of the trapezoidal portion 62B is shorter than the length of the lower base of the trapezoidal portion 62B. The trapezoidal portion 62B is in contact with the flat surface 32 of the flat plate portion 30, and the arc-shaped portion 63B is separated from the flat surface 32 of the flat plate portion 30. In the configuration example of the light guide plate 10 shown in FIG. 23C, the height of the trapezoidal portion 62B is 50% of the total value of the height of the trapezoidal portion 62B and the height of the arc-shaped portion 63B. The ratio of the height of the trapezoidal portion 62B to the sum of the height of the trapezoidal portion 62B and the height of the arc-shaped portion 63B is not limited to 50%. The ratio of the height of the trapezoidal portion 62B to the total value of the height of the trapezoidal portion 62B and the height of the arc-shaped portion 63B may be 0% or more and 100% or less.
　液晶表示装置で動画像を表示する場合において、液晶のスキャンに合わせて、複数の光源１１、４１の一部を非点灯状態とし、画面内を部分的に黒領域にすることで、液晶の切り替わりを視認させないようにして動画像における残像を低減することができる。このような動画像における残像を低減する技術は、バックライトスキャンと呼ばれる。実施形態に係る液晶表示装置によれば、導光板１０の上面２１から出射される光の輝度の広がりを抑制することができるため、画面内の部分的な黒領域の表示制御を向上することができる。また、このような液晶表示装置は、ＶＲ（Virtual Reality：仮想現実）技術を用いたコンテンツを表示する場合にも用いることができる。 When displaying a moving image on a liquid crystal display device, switching of the liquid crystal is performed by setting a part of the plurality of light sources 11 and 41 to a non-lighting state and partially changing the inside of the screen to a scan of the liquid crystal. It is possible to reduce an afterimage in a moving image by preventing the visual recognition of the A technique for reducing such residual images in moving images is called backlight scanning. According to the liquid crystal display device according to the embodiment, since the spread of the luminance of the light emitted from the upper surface 21 of the light guide plate 10 can be suppressed, the display control of the partial black region in the screen can be improved. it can. Also, such a liquid crystal display device can be used also when displaying content using VR (Virtual Reality) technology.
　更に、このような液晶表示装置は、各種の電子機器に搭載することができる。このような液晶表示装置を備えた電子機器として、スマートフォン、デジタルカメラ、タブレット端末、電子ブック、ウェアラブル機器、カーナビゲーション装置、電子辞書、電子広告板等を例示できる。 Furthermore, such a liquid crystal display device can be mounted on various electronic devices. A smartphone, a digital camera, a tablet terminal, an electronic book, a wearable device, a car navigation device, an electronic dictionary, an electronic advertisement board, etc. can be illustrated as an electronic device provided with such a liquid crystal display device.
１　　面光源装置
２　　表示パネル
１０　導光板
１１、４１　光源
１２　ＦＰＣ
１３　固定部材
１４　フレーム
１５　反射シート
１６　拡散シート
１７　プリズムシート
１８　遮光両面テープ
２３、３３　レンチキュラー
２３Ａ、２３Ｂ、３３Ａ、３３Ｂ　曲面
３０　平板部
３１、３２　平面
５１Ａ、５１Ｂ、６１Ａ、６１Ｂ　平坦面 Reference Signs List 1 surface light source device 2 display panel 10 light guide plate 11, 41 light source 12 FPC
13 fixing member 14 frame 15 reflection sheet 16 diffusion sheet 17 prism sheet 18 light shielding double- sided tape 23, 33 lenticular 23A, 23B, 33A, 33B curved surface 30 flat plate portion 31, 32 plane 51A, 51B, 61A, 61B flat surface

Claims (18)

  1. 　光が入射する入光面を側方に有し、前記入光面から入射する光を出光面から出射する概略平板状の導光板であって、
    　平板部と、
    　前記平板部の平面に設けられ、前記平面の法線方向から見て、前記入光面に対して垂直方向に延在する複数の凸条及び凹条の少なくとも一方と、
    　を備え、
    　前記複数の凸条及び凹条の少なくとも一方は前記平面に対して傾斜する傾斜面を有し、
    　前記出光面は、前記複数の凸条及び凹条の少なくとも一方の前記傾斜面によって形成され、
    　前記平面と前記複数の凸条及び凹条の少なくとも一方の端部における前記傾斜面の接線とでなす角度が３０度以上７０度以下である、
    　導光板。     A substantially flat light guide plate having a light incident surface on which light is incident, and emitting light incident from the light incident surface from the light exit surface,
    Flat part,
    At least one of a plurality of ridges and ridges provided on a flat surface of the flat plate and extending in a direction perpendicular to the light entrance surface as viewed from the normal direction of the flat surface;
    Equipped with
    At least one of the plurality of ridges and grooves has an inclined surface which is inclined with respect to the plane,
    The light exit surface is formed by the inclined surface of at least one of the plurality of ridges and grooves.
    The angle formed by the plane and the tangent of the inclined surface at the end of at least one of the plurality of ridges and grooves is 30 degrees or more and 70 degrees or less.
    Light guide plate.
  2. 　前記平面と前記複数の凸条及び凹条の少なくとも一方の端部における前記傾斜面の接線とでなす角度が４５度以上６０度以下である、
    　請求項１に記載の導光板。     The angle formed by the plane and the tangent of the inclined surface at the end of at least one of the plurality of ridges and grooves is 45 degrees or more and 60 degrees or less.
    The light guide plate according to claim 1.
  3. 　前記傾斜面は、曲面を含む、
    　請求項１又は２に記載の導光板。     The inclined surface includes a curved surface,
    A light guide plate according to claim 1 or 2.
  4. 　前記傾斜面は、曲面及び平坦面を含み、
    　前記平面と前記複数の凸条及び凹条の少なくとも一方の端部における前記平坦面とでなす角度が３０度以上７０度以下である、
    　請求項１に記載の導光板。     The inclined surface includes a curved surface and a flat surface,
    The angle between the flat surface and the flat surface at the end of at least one of the plurality of ridges and grooves is 30 degrees or more and 70 degrees or less.
    The light guide plate according to claim 1.
  5. 　前記傾斜面は、曲面及び平坦面を含み、
    　前記平面と前記複数の凸条及び凹条の少なくとも一方の端部における前記平坦面とでなす角度が４５度以上６０度以下である、
    　請求項１に記載の導光板。     The inclined surface includes a curved surface and a flat surface,
    The angle between the flat surface and the flat surface at the end of at least one of the plurality of ridges and grooves is 45 degrees or more and 60 degrees or less.
    The light guide plate according to claim 1.
  6. 　前記複数の凸条及び凹条の少なくとも一方を除いた前記導光板の厚みが０．２ｍｍ以上１．０ｍｍ以下である、
    　請求項１から５の何れか一項に記載の導光板。     The thickness of the light guide plate excluding at least one of the plurality of convex lines and concave lines is 0.2 mm or more and 1.0 mm or less.
    The light guide plate as described in any one of Claims 1-5.
  7. 　前記複数の凸条及び凹条の少なくとも一方が隙間なく前記平面に配置されている、
    　請求項１から６の何れか一項に記載の導光板。     At least one of the plurality of ridges and grooves is disposed in the plane without a gap;
    The light guide plate as described in any one of Claims 1-6.
  8. 　前記複数の凸条及び凹条の少なくとも一方が一定の間隔を空けて前記平面に配置され、
    　前記出光面は、前記複数の凸条及び凹条の少なくとも一方の前記傾斜面と前記平面とによって形成されている、
    　請求項１から３の何れか一項に記載の導光板。     At least one of the plurality of ridges and grooves is disposed in the plane at a constant interval,
    The light exit surface is formed by the inclined surface and the plane of at least one of the plurality of ridges and grooves.
    The light guide plate as described in any one of Claim 1 to 3.
  9. 　光が入射する入光面を側方に有し、前記入光面から入射する光を出光面から出射する概略平板状の導光板であって、
    　平板部と、
    　前記平板部の平面に設けられ、前記平面の法線方向から見て、前記入光面に対して垂直方向に延在する複数の凸条及び凹条の少なくとも一方と、
    　を備え、
    　前記複数の凸条及び凹条の少なくとも一方が一定の間隔を空けて前記平面に配置され、
    　前記複数の凸条及び凹条の少なくとも一方は前記平面に対して傾斜する傾斜面を有し、
    　前記出光面は、前記複数の凸条及び凹条の少なくとも一方の前記傾斜面と前記平面とによって形成され、
    　前記平面と前記複数の凸条及び凹条の少なくとも一方の端部における前記傾斜面の接線とでなす角度が３０度以上８０度以下である、
    　導光板。     A substantially flat light guide plate having a light incident surface on which light is incident, and emitting light incident from the light incident surface from the light exit surface,
    Flat part,
    At least one of a plurality of ridges and ridges provided on a flat surface of the flat plate and extending in a direction perpendicular to the light entrance surface as viewed from the normal direction of the flat surface;
    Equipped with
    At least one of the plurality of ridges and grooves is disposed in the plane at a constant interval,
    At least one of the plurality of ridges and grooves has an inclined surface which is inclined with respect to the plane,
    The light exit surface is formed by the inclined surface and the plane of at least one of the plurality of ridges and grooves.
    The angle formed by the plane and the tangent of the inclined surface at the end of at least one of the plurality of ridges and grooves is 30 degrees or more and 80 degrees or less.
    Light guide plate.
  10. 　前記平面と前記複数の凸条及び凹条の少なくとも一方の端部における前記傾斜面の接線とでなす角度が４５度以上６０度以下である、
    　請求項９に記載の導光板。     The angle formed by the plane and the tangent of the inclined surface at the end of at least one of the plurality of ridges and grooves is 45 degrees or more and 60 degrees or less.
    The light guide plate according to claim 9.
  11. 　前記傾斜面は、曲面を含む、
    　請求項９又は１０に記載の導光板。     The inclined surface includes a curved surface,
    A light guide plate according to claim 9 or 10.
  12. 　前記傾斜面は、曲面及び平坦面を含み、
    　前記平面と前記複数の凸条及び凹条の少なくとも一方の端部における前記平坦面とでなす角度が３０度以上８０度以下である、
    　請求項９に記載の導光板。     The inclined surface includes a curved surface and a flat surface,
    The angle between the flat surface and the flat surface at the end of at least one of the plurality of ridges and grooves is 30 degrees or more and 80 degrees or less.
    The light guide plate according to claim 9.
  13. 　前記傾斜面は、曲面及び平坦面を含み、
    　前記平面と前記複数の凸条及び凹条の少なくとも一方の端部における前記平坦面とでなす角度が４５度以上６０度以下である、
    　請求項９に記載の導光板。     The inclined surface includes a curved surface and a flat surface,
    The angle between the flat surface and the flat surface at the end of at least one of the plurality of ridges and grooves is 45 degrees or more and 60 degrees or less.
    The light guide plate according to claim 9.
  14. 　前記複数の凸条及び凹条の少なくとも一方を除いた前記導光板の厚みが０．２ｍｍ以上１．０ｍｍ以下である、
    　請求項９から１３の何れか一項に記載の導光板。     The thickness of the light guide plate excluding at least one of the plurality of convex lines and concave lines is 0.2 mm or more and 1.0 mm or less.
    The light guide plate as described in any one of Claims 9-13.
  15. 　請求項１から１４の何れか一項に記載の導光板と、
    　前記入光面と対向する位置に配置された光源と、
    　を備える面光源装置。     A light guide plate according to any one of claims 1 to 14,
    A light source disposed at a position facing the light incident surface;
    A surface light source device comprising
  16. 　請求項１から１４の何れか一項に記載の導光板と、
    　第１の光源と、
    　第２の光源と、
    　を備え、
    　前記入光面は、第１の入光面及び第２の入光面を含み、
    　前記第１の入光面と前記第２の入光面とが対向しており、
    　前記第１の光源は、前記第１の入光面と対向する位置に配置され、
    　前記第２の光源は、前記第２の入光面と対向する位置に配置されている、
    　面光源装置。     A light guide plate according to any one of claims 1 to 14,
    A first light source,
    A second light source,
    Equipped with
    The light entrance surface includes a first light entrance surface and a second light entrance surface.
    The first light entrance surface and the second light entrance surface are opposed to each other,
    The first light source is disposed at a position facing the first light incident surface,
    The second light source is disposed at a position facing the second light incident surface.
    Surface light source device.
  17. 　請求項１５又は１６に記載の面光源装置と、
    　前記面光源装置から出射される光を受ける表示パネルと、
    　を備える表示装置。     A surface light source device according to claim 15 or 16.
    A display panel for receiving light emitted from the surface light source device;
    A display device comprising:
  18. 　請求項１７に記載の表示装置を備える電子機器。 An electronic device comprising the display device according to claim 17.
PCT/JP2018/024675 2017-07-31 2018-06-28 Light guide plate, area light source device, display device, and electronic apparatus WO2019026495A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201880030641.8A CN110622050A (en) 2017-07-31 2018-06-28 Light guide plate, surface light source device, display device, and electronic apparatus

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2017-148555 2017-07-31
JP2017148555 2017-07-31
JP2018009489A JP2019029334A (en) 2017-07-31 2018-01-24 Light guide plate, plane light source device, display device, and electronics
JP2018-009489 2018-01-24

Publications (1)

Publication Number Publication Date
WO2019026495A1 true WO2019026495A1 (en) 2019-02-07

Family

ID=65233618

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2018/024675 WO2019026495A1 (en) 2017-07-31 2018-06-28 Light guide plate, area light source device, display device, and electronic apparatus

Country Status (1)

Country Link
WO (1) WO2019026495A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114604187A (en) * 2020-12-29 2022-06-10 深圳市合瑞软件有限公司 Automobile trim board assembly and automobile

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011175965A (en) * 2010-02-01 2011-09-08 Minebea Co Ltd Planar lighting device
JP2012104390A (en) * 2010-11-10 2012-05-31 Stanley Electric Co Ltd Surface light source device
JP2014130748A (en) * 2012-12-28 2014-07-10 Omron Corp Light guide plate and surface light source device
JP2016154119A (en) * 2015-02-20 2016-08-25 大日本印刷株式会社 Light guide plate, surface light source device and transparent type display device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011175965A (en) * 2010-02-01 2011-09-08 Minebea Co Ltd Planar lighting device
JP2012104390A (en) * 2010-11-10 2012-05-31 Stanley Electric Co Ltd Surface light source device
JP2014130748A (en) * 2012-12-28 2014-07-10 Omron Corp Light guide plate and surface light source device
JP2016154119A (en) * 2015-02-20 2016-08-25 大日本印刷株式会社 Light guide plate, surface light source device and transparent type display device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114604187A (en) * 2020-12-29 2022-06-10 深圳市合瑞软件有限公司 Automobile trim board assembly and automobile
CN114604187B (en) * 2020-12-29 2024-05-10 深圳市合瑞软件有限公司 Automobile decoration plate assembly and automobile

Similar Documents

Publication Publication Date Title
US9223074B2 (en) Light guide plate and area light source device
KR101473608B1 (en) Surface light source device, lcd device and mobile device
EP2293124A1 (en) Light guide panel and display device employing the same
US7309153B2 (en) Surface light source device and display
JP2007258152A (en) Backlight unit and display device provided with the same
JP2010217660A (en) Optical unit, backlight device, liquid crystal module and liquid crystal display
WO2016194716A1 (en) Edge-lit backlight device and liquid crystal display device
WO2017115472A1 (en) Light-guide plate, surface light source device, display device, and electronic apparatus
US20070133225A1 (en) Lighting unit, electro-optic device, and electronic apparatus
JP2018017804A (en) Display device
JP2001066592A (en) Electronic instrument equipped with nonemissive display device, light transmission plate and illuminator
WO2017159556A1 (en) Lighting device and display device
JP2017187548A (en) Display device
TWI670526B (en) Light guide plate, surface light source device, display device, and electronic device
WO2019026495A1 (en) Light guide plate, area light source device, display device, and electronic apparatus
JP2014130832A (en) Surface light source device, liquid crystal display apparatus and mobile equipment
JP6682834B2 (en) Light guide plate, surface light source device, display device, and electronic device
KR101571344B1 (en) Bottom case and backlight assembly having the same
CN110291454B (en) Illumination device and display device
US20210215965A1 (en) Display device
JP2019029334A (en) Light guide plate, plane light source device, display device, and electronics
JP6707921B2 (en) Surface light source device, display device, electronic device, and light source
US20140328051A1 (en) Display device
US11947152B1 (en) Display module including a through-hole and photosensitive element and a display device including the same
US11808963B2 (en) Illumination device and display device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 18841071

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 18841071

Country of ref document: EP

Kind code of ref document: A1