KR20060119342A - Optical plate, and backlight assembly and display device having the same - Google Patents

Abstract

An optical plate, a backlight assembly having the same, and a display device are provided to minimize the generation of dark portions and bright lines and enhance the efficiency of light, by scattering the light supplied onto a rear surface of the optical plate using rounded prisms formed on a light exiting surface of the optical plate. An optical plate(10) comprises a flat base(12) and a plurality of rounded prisms(14) formed on the flat base. The rounded prisms improve the uniformity of light passing through the flat base. Each of the prisms includes a rounded peak portion and two inclined portions. The rounded peak portion diffuses a backlight into a first diffusing light, and the inclined portions diffuse the backlight into a second diffusing light. The first diffusing light has a single peak value lower than a peak value of the backlight. The second diffusing light has two peak values lower than the peak value of the backlight and the peak value of the first diffusing light.

Description

OPTICAL PLATE, AND BACKLIGHT ASSEMBLY AND DISPLAY DEVICE HAVING THE SAME}

1 is a cross-sectional view illustrating an optical path of a backlight assembly having a general diffuser plate.

2A to 2D are views illustrating an optical plate according to an embodiment of the present invention.

3 is a schematic diagram illustrating an optical effect by a rounded prism according to an embodiment of the present invention.

4 is a cross-sectional view illustrating an optical plate according to another exemplary embodiment of the present invention.

5A through 5E are process diagrams illustrating a method of manufacturing the optical plate illustrated in FIG. 2A.

6 is a cross-sectional view schematically illustrating a backlight assembly according to an embodiment of the present invention.

7 is a graph showing the results of the optical analysis observed by applying the round-shaped prism array-shaped optical plate according to the present invention to a flat fluorescent lamp.

8 is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.

9 is an exploded perspective view of a liquid crystal display according to another exemplary embodiment of the present invention.

10 is an exploded perspective view of a liquid crystal display according to another exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10, 20: optical plate 12, 22, 122: flat base portion

14, 124: lens section 24: lens array sheet

26: adhesive member SUB: base substrate

STG: Stage ROL: Roller

FS: Father Stamper DS: Daughter Stamper

RSN: UV Curing Resin

The present invention relates to an optical plate, a backlight assembly and a display device having the same, and more particularly, to an optical plate, a backlight assembly and a display device having the same for increasing the light efficiency.

The backlight assembly employed in the liquid crystal display (LCD) plays an important role in screen brightness and appearance. The backlight assembly is classified into a lamp assembly, a light guide plate or a diffuser plate assembly, a housing unit, and the like.

The backlight assembly employed in the LCD TV has a structure in which a diffusion plate, a diffusion sheet, and a brightness enhancement sheet are sequentially stacked as an optical unit. In the above structure, as light passes through media having different refractive indices, energy transfer occurs, and thus, a large amount of light sources are lost.

In addition, by using a variety of sheets in the above structure, there is a problem in that the handling of the sheets occurs, the production cost rises.

1 is a cross-sectional view illustrating an optical path of a backlight assembly having a general diffuser plate.

Referring to FIG. 1, a general diffuser plate 2 is disposed on a plurality of lamps 4 arranged in parallel to diffuse light provided from each lamp 4 and light provided from the reflector plate 6. Exit. At this time, a bright line and a dark line due to the pitch of the lamps 4 are generated on the surface of the diffusion plate 2. The bright line is generated in a region A relatively close to the lamp 4, and the dark line is generated in a region B relatively far from the lamp 4.

The bright line and the dark line are different depending on the thickness and efficiency of the diffusion plate 2. That is, the thinner the diffusion plate 10, the higher the light transmittance and the lower the uniformity, while the thicker the diffusion plate 2, the higher the uniformity, the lower the light transmittance. This is because, as the light path is scattered, the diffusion distribution ratio is high, and thus the lamp loss is high.

In order to remove the dark portion and the bright line, the optical films are disposed on the diffusion plate, or the distance between the lamp and the diffusion plate is further separated. The arrangement or spacing of the optical sheets is problematic in increasing the thickness of the liquid crystal display module. Therefore, one or two diffusion sheets are further arranged to remove the dark portion and the bright line. The use of optical sheets such as the diffusion sheet has a problem of causing an increase in cost.

In addition, there is a problem that the efficiency is lowered according to the increase of the parts lost in light efficiency.

Accordingly, the technical problem of the present invention is to solve such a conventional problem, and an object of the present invention is to provide an optical plate in which rounded prisms are formed in order to increase light efficiency while minimizing the generation of dark portions and bright lines.

Another object of the present invention is to provide a backlight assembly having the above optical plate.

Another object of the present invention is to provide a display device having the above optical plate.

In order to achieve the above object of the present invention, an optical plate according to an embodiment includes a flat plate base portion and a plurality of rounded prisms. The rounded prisms are formed on the flat plate base to improve the uniformity of the light passing through the flat plate base part. Each of the prisms has rounded vertices and two inclined portions connected to the vertices, wherein the vertices disperse a predetermined pulse of back light into a first diffused light, and the inclined portion of a predetermined pulse of back light. Is dispersed in a second diffused light, wherein the first diffused light has one peak value and is relatively smaller than the peak value of the back light, and the second diffused light has two peak values and is relatively smaller than the peak value of the back light. And smaller than the peak value of the first diffused light.

In order to realize the above object of the present invention, the backlight assembly includes a light source unit and an optical plate. The light source unit emits light. The optical plate has a flat plate base portion and a plurality of rounded prisms formed on the flat plate base portion to improve the uniformity of the light provided from the light source unit and emit the light.

In accordance with another aspect of the present invention, a display device includes a display panel, a light source unit, and a diffusion unit. The display panel displays an image using light. The light source unit is disposed under the display panel to emit light. The diffusion unit has a flat plate base portion and a plurality of rounded prisms formed on the flat plate base portion to improve the uniformity of the light provided from the light source unit and emit the light.

According to such an optical plate, a backlight assembly and a display device having the same, light efficiency may be scattered by the rounded prisms formed on the emission surface to increase light efficiency while minimizing dark portion and bright line generation.

Hereinafter, with reference to the accompanying drawings, it will be described in detail the present invention.

<Example 1 of the optical plate>

2A to 2D are views illustrating an optical plate according to an embodiment of the present invention. In particular, FIG. 2A is a perspective view of the optical plate, FIG. 2B is a plan view of the optical plate, FIG. 2C is a sectional view of the optical plate, and FIG. 2D is a sectional view of a unit rounded prism of the optical plate.

2A to 2D, an optical plate 10 according to an embodiment of the present invention includes a flat plate base portion 12 and a lens portion 14 formed to protrude convexly on the flat plate base portion 12. do.

The flat base portion 12 is made of a transparent plastic plate having a thickness of approximately 1 to 2 mm. The plastic plate is made of a transparent, high refractive index polycarbonate-series resin (PC), polymethylmethacrylate-serises resin (PMMA), methacrylate-styrene copolymer It is a material such as polymer (Methacrylate-styrene copolymer, MS).

The lens portion 14 includes prisms with rounded vertices. The ratio of the pitch (or base length) of the prism to the radius of curvature of the rounded vertex of the prism satisfies the condition of 100: 30 to 100: 38. Preferably, the ratio of the base length of the prism to the radius of curvature of the rounded vertex of the prism satisfies the condition of 100: 34.

The pitch of the prism is 50 to 200 mu m, and the radius of curvature of the rounded vertex is 15 to 76 mu m. For example, if the pitch of the prism is 50 µm, the radius of curvature of the rounded vertex is 15 µm, and if the pitch of the prism is 200 µm, the radius of curvature of the rounded vertex is 76 µm.

The inclination angle of the prism is 43 to 47 degrees, and the height of the prism is about 50 μm. The rounded prisms are formed to be as geometrically dense as possible. Accordingly, the rounded prisms are not formed so that the area where the flat base portion is exposed is almost zero.

Although not shown, it may further include a UV light blocking coating layer formed on the rear surface of the flat base portion 12 to block the high energy wavelength band of light provided from the rear surface from being applied to the flat base portion 12. have. In particular, if the flat base portion is made of a PC material, the UV light blocking coating layer should be further included.

In addition, it may further include UV light blocking particles formed on the flat plate base portion 12 to block the application of the high energy wavelength band of light provided from the rear surface to the prisms.

3 is a schematic diagram illustrating an optical analysis by a rounded prism according to an embodiment of the present invention.

Referring to FIG. 3, as the back light in the form of a pulse is incident on the vertex portion (round portion or upper circular surface) of the rounded prism, the vertex portion is dispersed as the first diffused light (at the left side of the drawing). city). Here, the first diffused light has one peak value and is relatively smaller than the peak value of the back light. However, since the round part of the prism has a relatively short distance from a light source such as a flat fluorescent lamp, the light scattering effect cannot be obtained to the extent that the bright and dark lines of the light source are not visible only by the circular structure.

On the other hand, as the back light in the form of a constant pulse is incident on the inclined portion (or trapezoidal portion) of the prism, the inclined portion is dispersed into the second diffused light (shown on the right side of the drawing). The second diffused light has two peak values and is relatively smaller than the peak value of the back light and is relatively smaller than the peak value of the first diffused light. However, since the light is distributed in two directions by the inclined portion, bright and dark lines are generated.

As described above, it can be seen that the shortcomings caused by the prism round part are secured in the inclined part of the prism, and the shortcomings caused by the prism inclined part are secured in the prism round part.

<Example 2 of Optical Plate>

4 is a cross-sectional view illustrating an optical plate according to another exemplary embodiment of the present invention.

Referring to FIG. 4, an optical plate 20 according to another embodiment of the present invention may include a flat plate base 22, a lens array sheet 24 having a plurality of rounded prisms, and the flat plate base 22. And an adhesive member 26 for physically coupling the lens array sheet 24.

The flat base portion 22 is made of a transparent plastic plate having a thickness of 1 to 2 mm. The plastic plate may be made of a transparent and high refractive index polycarbonate-serises resin (PC), polymethylmethacrylate-serises resin (PMMA), methacrylate-styrene copolymer It is a material such as polymer (Methacrylate-styrene copolymer, MS).

A plurality of rounded prisms are formed on the lens array sheet 24. The rounded prisms are as shown in FIG. 2D. That is, the ratio of the base length of the prism to the radius of curvature of the rounded vertex of the prism satisfies the condition of 100: 30 to 100: 38. Preferably, the ratio of the base length of the prism to the radius of curvature of the rounded vertex of the prism satisfies the condition of 100: 34.

The adhesive member 26 may be a cured adhesive or may be an adhesive tape having an adhesive layer formed on both surfaces thereof.

In FIG. 4, although the adhesive member 26 is interposed between the flat plate base part 22 and the lens array sheet 24, the adhesive member 26 may be omitted.

Although not shown, it may further include a UV light blocking coating layer formed on the rear surface of the flat base portion 12 to block the high energy wavelength band of light provided from the rear surface from being applied to the flat base portion 12. have.

In addition, it may further include UV light blocking particles formed on the flat plate base portion 12 to block the application of the high energy wavelength band of light provided from the rear surface to the prisms.

Next, a method of manufacturing an optical plate having a rounded prism shape according to an embodiment of the present invention will be described.

<Method for Manufacturing Optical Plate-1>

5A through 5E are process diagrams illustrating a method of manufacturing the optical plate illustrated in FIG. 2A.

First, as shown in FIG. 5A, a base substrate SUB on which a metal such as pure copper, brass, aluminum, or nickel is deposited about 1 mm is prepared on the stage STG, and then the surface is mirror-polished using a flat diamond tool. do.

Subsequently, as shown in FIG. 5B, grooves having a predetermined depth are formed on the surface of the resultant product of FIG. 5A by using a roller ROL having a protrusion formed at an outer portion thereof. The protrusion extends parallel to the axial direction of the roller. The pitch, the inclination angle of the protrusion, and the radius of curvature of the round part are shown in FIG. 2D, but the roller ROL forming the groove is shown in FIG. 5B, but a tool such as a diamond bite may be used. . The grooves are for defining the rounded prism of the optical plate in the shape of the rounded prism array in the future.

Subsequently, as shown in FIG. 5C, a father stamper FS is formed through a cast-iron product in which a molten metal is formed on the resultant of FIG. 5B and then solidified. Accordingly, the father stamper FS is manufactured to have a shape opposite to that of the base substrate SUB having grooves formed on a surface thereof.

Subsequently, as illustrated in FIG. 5D, a daughter stamper having a shape opposite to that of the father stamper FS through a casting process of forming and solidifying a dissolved metal on the resultant product of FIG. 5C. stamper (DS). Here, in manufacturing a stamper for forming an optical plate in the form of a rounded prism array, when manufacturing a large number of optical plates using the stamper, a plurality of stampers are provided to manufacture several optical plates at once. Needs to be. In this case, if a plurality of stampers are manufactured from the base substrate SUB, a portion of the base substrate SUB coming into contact with the stamper may be worn, resulting in poor shape. Therefore, in the embodiment of the present invention, a plurality of daughter stampers are manufactured using the father stamper. The daughter stamper is then used to fabricate an optical plate in the form of a rounded prism array.

As described above, when the optical plate is molded using two stampers, the shape of the father stamper FS and the optical plate to be molded are the same, and the shape of the base substrate and the daughter stamper DS is the same. Should be. Therefore, the shape of the father stamper FS and the shape of the optical plate to be molded are reversed.

Subsequently, as shown in FIG. 5E, the UV-cured resin RSN is filled on the surface of the trench stamper DS according to FIG. 5D, and the transparent base plate 12 is positioned. The UV cured resin (RSN) is preferably a material having the same refractive index as the flat base portion 12.

Subsequently, the UV curing resin RSN is attached to one surface of the flat plate base part 12 by irradiating UV light while pressing the edge region of the flat plate part 12 through the outer crimping pole POL. As the UV cured resin RSN is attached to the flat plate base 12, the optical plate having the rounded prism array shape shown in FIGS. 2A to 2D is completed.

<Example of Backlight Assembly>

6 is a cross-sectional view schematically illustrating an optical path of a backlight assembly according to an embodiment of the present invention.

Referring to FIG. 6, the backlight assembly 100 according to an exemplary embodiment of the present invention is disposed on the flat panel fluorescent lamp 110 and the flat panel fluorescent lamp 110 that emit light, and thus, in the flat panel fluorescent lamp 110. It includes an optical plate 120 to improve the uniformity of the light provided to the exit. As shown in FIGS. 2A to 2D, the optical plate 120 has a flat plate base portion 122 and a plurality of rounded prisms 124 formed on the flat plate base portion 122. The optical plate 120 has heat resistance.

The plate fluorescent lamp 110 includes a lamp body L10 and a first external electrode L20. The lamp body L10 has a plurality of discharge spaces L30 intermittently formed parallel to each other on the same plane when viewed from a cross section.

The first external electrodes L20 are formed on the outer surface of the lamp body L10 and are formed at both ends in the longitudinal direction of the discharge space L30 so as to intersect with all the discharge spaces L30.

The lamp body L10 is formed of a rear substrate L40 and a front substrate L50 coupled to the rear substrate L40 to form discharge spaces L30. The rear substrate L40 has a rectangular flat plate shape. For example, the rear substrate L40 includes a transparent glass substrate that transmits visible light and blocks ultraviolet rays. The front substrate L50 is combined with the rear substrate L40 to form discharge spaces L30. For example, the front substrate L50 is formed of the same transparent glass substrate as the rear substrate L40.

The front substrate L50 is formed between the plurality of discharge space portions L52 and the adjacent discharge space portions L52 that are spaced apart from the rear substrate L40 to form discharge spaces L30, and the rear substrate ( A plurality of space dividers L54 in contact with L40 and a sealing portion L56 formed at edges of the discharge spaces L52 and the space dividers L54 and coupled to the rear substrate L40 are formed.

Various kinds of discharge gases for plasma discharge are injected into the discharge spaces L30. For example, the discharge gas may include mercury (Hg), neon (Ne), argon (Ar), xenon, krypton, and the like. The gas pressure of the discharge gas present in the discharge spaces L30 is about 50 tor, and a pressure difference is generated in comparison with the external atmospheric pressure of 760 tor. Due to this pressure difference, a force directed from the outside to the inside of the lamp body L10 is generated, and the space dividing portion L54 is in close contact with the rear substrate L40 by this force.

The lamp body L10 further includes a first fluorescent layer L42 formed on an inner surface of the rear substrate L40, a reflective layer L44, and a second fluorescent layer L58 formed on an inner surface of the front substrate L50. Include. The first and second fluorescent layers L42 and 158 are excited by ultraviolet rays generated through plasma discharge in the discharge spaces L30 to emit visible light. The reflective layer L44 is formed between the rear substrate L40 and the first fluorescent layer L42. The reflective layer L44 reflects visible light generated by the first and second fluorescent layers L42 and 158 toward the front substrate L50 to prevent light from leaking through the rear substrate L40. .

The first external electrode L20 is formed on an outer surface of the front substrate L50. The first external electrode L20 is formed at both ends of the front substrate L50 in a direction perpendicular to the length direction of the discharge space L52 to overlap all of the discharge spaces L30.

As such, a relatively large amount of light is emitted in a region where the discharge space L30 is formed, and a relatively small amount of light is emitted in a region where the discharge space L30 is not formed. Accordingly, a bright line is generated in a region where a relatively large amount of light is emitted, and a dark portion is generated in a region where a relatively small amount of light is generated.

However, by increasing the degree of light diffusion by the rounded prism of the optical plate 120 according to the present invention, the difference between the bright line and the dark portion is minimized while minimizing the occurrence of the bright line or the dark portion generated on the surface of the optical plate 120 can do.

In the above, the arrangement of the rounded prism array-shaped optical plate on the backlight assembly having the flat fluorescent lamp has been described as an embodiment, but those skilled in the art have described the rounded prism-shaped optical plate in the direct type backlight assembly having the plurality of lamps. Obviously, it may be disposed in a backlight assembly having a plurality of light emitting diodes.

7 is a graph showing the results of the optical analysis observed by applying the optical plate according to the present invention to a flat fluorescent lamp.

Referring to FIG. 7, a lenticular lens array type optical plate has a luminance distribution range of 520 to 680 [cd / m ² ] for back light having a luminance distribution range of 80 to 750 [cd / m ² ]. Disperse to The lenticular lens has a shape protruding in a semi-circular shape toward the viewer, and diffuses an image to provide a 180 degree viewing angle around the screen.

However, the rounded prism array type optical plate according to the present invention has a luminance distribution range of 80 to 750 [cd / m ² ] so that the incident light has a luminance distribution range of 580 to 610 [cd / m ² ]. Disperse

Therefore, it can be confirmed that the light scattering effect by the optical plate according to the present invention is superior to that of the optical plate of the lenticular lens array type, which is generally proposed for slimming the backlight assembly.

<Example 1 of Display Device>

8 is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention. In particular, a liquid crystal display device having a backlight assembly provided with a flat fluorescent lamp is shown.

Referring to FIG. 8, the liquid crystal display according to the exemplary embodiment includes a storage container 210, a flat panel fluorescent lamp 220, an inverter 230, and a display unit 300.

The storage container 210 has a storage space for accommodating the flat fluorescent lamp 220.

The flat fluorescent lamp 220 is divided into a plurality of discharge spaces to generate a lamp body, an external electrode formed to intersect the discharge spaces at both ends of the lamp body and an auxiliary coupled to the lamp body in contact with the external electrode An electrode.

Specifically, in order to emit light in the form of a plane, the lamp body has a rectangular shape as viewed from above. The lamp body generates plasma discharge in the discharge spaces by the discharge voltage applied from the inverter 230 to the external electrode, and converts the ultraviolet rays generated by the plasma discharge into visible light and emits them to the outside.

Since the lamp body has a large light emitting area, the internal space is divided into a plurality of discharge spaces to improve the light emitting efficiency and uniform light emission. The lamp body includes a first substrate and a second substrate coupled to each other to form a plurality of discharge spaces.

The inverter 230 generates a discharge voltage for emitting light of the plate fluorescent lamp 220.

The display unit 300 includes a liquid crystal display panel 310 for displaying an image using light supplied from the flat panel fluorescent lamp 220, and a driving circuit unit 320 for driving the liquid crystal display panel 310. do.

The liquid crystal display panel 310 includes a first substrate 312, a second substrate 314 coupled to face the first substrate 312, and between the first substrate 312 and the second substrate 314. The interposed liquid crystal layer 316 is included.

The first substrate 312 is a TFT substrate in which a thin film transistor (hereinafter, referred to as TFT) as a switching element is formed in a matrix form. In one example, the first substrate 312 is made of a glass material. A data line and a gate line are respectively connected to the source terminal and the gate terminal of the TFTs, and a pixel electrode made of a transparent conductive material is connected to the drain terminal.

The second substrate 314 is a color filter substrate in which RGB pixels for realizing color are formed in a thin film form. The second substrate 314 is made of, for example, a glass material. The common electrode made of a transparent conductive material is formed on the second substrate 314.

In the liquid crystal display panel 310 having such a configuration, when power is applied to the gate terminal of the TFT and the TFT is turned on, an electric field is formed between the pixel electrode and the common electrode. The arrangement of the liquid crystal molecules of the liquid crystal layer 316 interposed between the first substrate 312 and the second substrate 314 is changed by the electric field, and is supplied from the flat fluorescent lamp 220 according to the change of the arrangement of the liquid crystal molecules. The transmittance of light to be changed is displayed to display an image of a desired gray scale.

The driving circuit unit 320 may include a data printed circuit board 322 for supplying a data driving signal to the liquid crystal display panel 310, and a gate printed circuit board 324 for supplying a gate driving signal to the liquid crystal display panel 310. And a data flexible printed circuit film 326 connecting the data printed circuit board 322 to the liquid crystal display panel 310 and a gate flexible connecting the gate printed circuit board 324 to the liquid crystal display panel 310. The printed circuit film 328 is included. The data flexible printed circuit film 326 and the gate flexible printed circuit film 328 may include, for example, a tape carrier package (TCP) or a chip on film (COF).

The data printed circuit board 322 is disposed on the side or the back of the storage container 210 by bending the data flexible printed circuit film 326, and the gate printed circuit board 324 is the gate flexible printed circuit film. By the bending of 328 is disposed on the side or rear of the storage container 210. The gate printed circuit board 324 may be removed by forming separate signal lines on the liquid crystal display panel 310 and the gate flexible printed circuit film 328.

The liquid crystal display 200 further includes an optical plate 250 disposed on the flat fluorescent lamp 220 to diffuse light emitted from the flat fluorescent lamp 220 to improve uniformity of brightness of the light. The optical plate 250 has a round prism array shape, is formed in a plate shape having a predetermined thickness, and is spaced apart from the plate fluorescent lamp 220 at a predetermined interval. The optical plate 250 is made of a transparent material for transmitting light, and includes a diffusing agent for diffusing light. For example, the optical plate 250 is made of polymethyl methacrylate (PMMA).

The liquid crystal display 200 further includes a middle mold 240 disposed between the planar fluorescent lamp 220 and the optical plate 250. The middle mold 240 is coupled to the storage container 210 from the top of the flat fluorescent lamp 220 to fix the flat fluorescent lamp 220. The middle mold 240 fixes an edge of the flat fluorescent lamp 220 while covering an external electrode region where light is not actually emitted, and supports the edge of the optical plate 250. The middle mold 240 may be integrally formed in a frame shape, may be formed of two pieces having a “c” or “a” shape, or may be divided into four pieces corresponding to each side.

The middle mold 240 is preferably made of a plastic material (hereinafter referred to as heat dissipation plastic) having a thermal conductivity of 20 (W / m * k) or more. An example of the heat-dissipating plastic is a product called CoolPoly manufactured by CoolPolymer. The cool poly is a thermally conductive plastic and has a thermal conductivity in the range of 10 (W / m * k) to 100 (W / m * k). Here, W, m and k represent Watt, Meter, and Kelvin, respectively.

The liquid crystal display 200 further includes an upper mold 260. The upper mold 260 is disposed between the optical plate 250 and the liquid crystal display panel 310. The upper mold 260 fixes the edge of the optical plate 250 and supports the edge of the liquid crystal display panel 310. Like the middle mold 240, the upper mold 260 may be integrally formed in a frame shape or may have a structure divided into two or four pieces.

The liquid crystal display device 200 further includes a buffer member 270 disposed between the storage container 210 and the flat plate fluorescent lamp 220 to support the flat plate fluorescent lamp 220. The buffer member 270 is disposed to correspond to an edge of the flat fluorescent lamp 220, and the flat fluorescent lamp 220 is spaced apart from the storage container 210 at a predetermined distance from the flat fluorescent lamp 220. It blocks the electrical contact between the metal storage container 210. To this end, the buffer member 270 is made of an insulating material. In addition, the buffer member 270 is preferably made of a material having a certain degree of elasticity in order to absorb the impact applied from the outside. For example, the buffer member 270 is made of silicon material. The buffer member 270 is composed of two pieces having a "c" shape. In contrast, the buffer member 270 is formed of four pieces corresponding to each side of the flat fluorescent lamp 220, or is formed of four pieces corresponding to four corners of the flat fluorescent lamp 220, Or it may be formed integrally of the frame shape.

The liquid crystal display 200 further includes a top chassis 280 for fixing the display unit 300. The top chassis 280 is coupled to the storage container 210 to fix an edge of the liquid crystal display panel 310. In this case, the data printed circuit board 322 is bent by the data flexible printed circuit film 326 and fixed to the side or bottom of the storage container 210. The top chassis 280 is made of, for example, a metal having little deformation and excellent strength.

<Example 2 of Display Device>

9 is an exploded perspective view of a liquid crystal display according to another exemplary embodiment of the present invention. In particular, a liquid crystal display having a backlight assembly provided with a cold cathode fluorescent lamp (CCFL) is shown.

Referring to FIG. 9, a liquid crystal display according to another exemplary embodiment of the present invention may include a display unit 400 for displaying an image by using light and a rear surface of the display unit 400 to the display unit 400. And a storage container 600 accommodating the backlight assembly 500, the display unit 400, and the backlight assembly 500 that provide the light.

The display unit 400 includes a display panel 410 for displaying an image, a gate side and a data side printed circuit board 420 and 430 for driving the display panel 410. The display panel 410 may include a first substrate (not shown), a second substrate facing the first substrate (not shown), and a liquid crystal layer (not shown) interposed between the first substrate and the second substrate. It includes.

The first substrate is a transparent glass substrate in which a thin film transistor (TFT), which is a switching element, is formed in a matrix form. The data line is connected to the source terminal of the thin film transistor, and the gate line is connected to the gate terminal. In addition, a pixel electrode made of a transparent conductive material is connected to the drain terminal of the thin film transistor.

The second substrate is a color filter substrate disposed to face the first substrate at a predetermined interval. The color filter substrate is a substrate in which an RGB pixel, which is a color pixel expressed in a predetermined color as light passes, is formed by a thin film process. A common electrode made of ITO is formed on the front surface of the first substrate.

In the liquid crystal display panel 410 having such a configuration, when power is applied to the gate terminal and the source terminal of the thin film transistor and the TFT is turned on, an electric field is formed between the pixel electrode and the common electrode. Such an electric field changes the arrangement angle of the liquid crystal injected between the TFT substrate (not shown) and the color filter substrate (not shown), and the light transmittance is changed according to the changed arrangement angle to obtain an image having a desired gradation.

The backlight assembly 500 may include a lamp unit 510 including a plurality of lamps 511 for generating light, a lamp holder 520 for fixing the lamps 511, and light of the lamp unit 510. The optical plate 540 is provided to improve the luminance uniformity and the viewing angle of light while emitting the light. Since the optical plate 540 has been described above with reference to FIGS. 2A to 2D, a detailed description thereof will be omitted.

Although the lamp unit 510 is illustrated as a plurality of rod-shaped lamps 511 arranged in parallel, a U-shaped lamp may be used. It is preferable that a reflecting plate (not shown) is further disposed below the lamp unit 510.

In addition, the lamp 511 may be used as a cold cathode fluorescent lamp (CCFL) having an internal lamp electrode or an external electrode lamp (EEFL) having an external lamp electrode. In addition, as a light source, the lamp unit 510 may be replaced with a light-emitting diode (LED).

The inverter 570 applies a driving signal to the lamp unit 510 and is usually manufactured in the form of a printed circuit board (PCB). The inverter cover 572 is made of metal to prevent electromagnetic interference (EMI) generated from the inverter 570.

The lamp holder 520 is coupled to the storage container 580 to surround the electrode portion of the lamp 511 to prevent the flow of the lamp 511. The reflective sheet 545 and the storage container 590 have coupling holes 5501 and 591 to be coupled to the lamp holder 520.

The reflective sheet 545 is provided under the lamp unit 510 to reflect the light emitted from the lamp unit 510 toward the display panel 410, and is formed in an area corresponding to the lamp holder 520. The hole 584 is formed.

The lamp fixing part 530 fixes the lamp 511 such that lamps adjacent to each other maintain a predetermined interval in a horizontal direction. In addition, the lamp fixing part 530 further includes an optical plate support part to maintain a predetermined distance between the optical plate 540 and the lamp unit 510. The lamp fixing part 530 passes through a hole formed in the reflective sheet 545 and is coupled to the storage container 580.

The backlight assembly 500 further includes first and second side molds 550 and 560. The first and second side molds 550 and 560 are combined with the storage container 580 to accommodate both ends of the lamp unit 510.

Optical plates 540 are mounted on upper surfaces of the first and second side molds 550 and 560. At least one of the first and second side molds 550 and 560 further includes an optical plate flow preventing part 552 and an optical sheet fixing part 553 that prevent the flow of the optical plate 540. The first and second side molds 550 and 560 may be made of a plastic material (hereinafter referred to as heat dissipating plastic) having a thermal conductivity of 20 (W / m * k) or more. An example of the heat dissipating plastic may include a product called CoolPoly manufactured by CoolPolymer. The cool poly is a thermally conductive plastic and is known to have a thermal conductivity in the range of 10 (W / m * k) to 100 (W / m * k). Here, W, m and k represent Watt, Meter, and Kelvin, respectively.

Heat generated in the lamp unit 510 is transferred to the first and second side molds 550 and 560. The first and second lower molds 550 and 560 made of a heat-dissipating plastic material transfer the transferred heat to the storage container 580 to be described later.

The optical plate 540 diffuses and emits light incident from the lamp unit 510.

The middle mold 590 is coupled to the receiving container 580 to prevent the flow of the optical plate 540. In addition, the display panel 410 is mounted on the top surface of the middle mold 590. The upper surface of the middle mold 590 further includes a panel guide member 592 guiding a position thereof when the display panel 410 is seated, and the panel guide member 592 is made of an elastic member such as rubber. It is preferably formed. The panel guide member 592 may be integrally formed with the middle mold 590. The panel guide member 592 is preferably formed in the corner region of the upper surface of the middle mold 590.

The storage container 580 accommodates the display panel 410 and the backlight assembly 500 in a storage space formed of a bottom surface and sidewalls, and is made of metal.

The top chassis 500 is coupled to the storage container 580 to fix the display unit 400 and the backlight assembly 500 to a designated position.

<Example 3 of Display Device>

10 is an exploded perspective view of a liquid crystal display according to another exemplary embodiment of the present invention. In particular, a liquid crystal display device having a backlight assembly provided with a plurality of light emitting diodes is shown.

Referring to FIG. 10, a liquid crystal display according to another exemplary embodiment of the present invention includes a storage container 600, a light generating device 700, and a display unit 800.

The storage container 600 includes a bottom portion 610 and a side portion 620 extending from an edge of the bottom portion 610 to form a storage space, and accommodates the light generating device 700. The storage container 600 is, for example, made of a metal having excellent strength and little deformation.

The light generating device 700 is disposed on the bottom 610 of the storage container 600 to generate light. The light generating device 700 is provided on the bottom portion 610 of the storage container 600 in order to uniformly emit light over a large area. The plurality of light generating apparatuses 700 are spaced at regular intervals and arranged in parallel to each other. In this case, the point light source units 720 formed on the circuit board 710 are arranged in a zigzag form between the light generating apparatuses 700 adjacent to each other. That is, the point light source units 720 included in one light generating device 700 are disposed between the point light source units 720 included in the adjacent light generating device 700.

On the other hand, the light generating device 700 may have a structure in which the point light source units 720 are arranged in a plurality of columns on one circuit board 710. In addition, the circuit board 710 may be disposed outside the storage container 600, and only the point light source units 720 may be inserted into the storage container 600.

The display unit 800 includes a display panel 810 for displaying an image using light supplied from the light generating device 700, and a driving circuit unit 820 for driving the display panel 810.

The display panel 810 is interposed between a first substrate 812, a second substrate 814 coupled to the first substrate 812, and between the first substrate 812 and the second substrate 814. A liquid crystal layer (not shown).

The first substrate 812 is a TFT substrate in which a thin film transistor (hereinafter, referred to as TFT) as a switching element is formed in a matrix form. For example, the first substrate 812 is made of glass. A data line and a gate line are respectively connected to the source terminal and the gate terminal of the TFTs, and a pixel electrode made of a transparent conductive material is connected to the drain terminal.

The second substrate 814 is a color filter substrate in which RGB pixels for realizing color are formed in a thin film form. The second substrate 814 is made of, for example, a glass material. A common electrode made of a transparent conductive material is formed on the second substrate 814.

In operation, when the power is applied to the gate terminal of the TFT and the TFT is turned on, an electric field is formed between the pixel electrode and the common electrode. The arrangement of the liquid crystal molecules of the liquid crystal layer interposed between the first substrate 812 and the second substrate 814 is changed by the electric field, and is supplied from the light generating device 700 according to the arrangement change of the liquid crystal molecules. The transmittance of light is changed to display an image of a desired gray scale.

The driving circuit unit 820 may include a data printed circuit board 821 supplying a data driving signal to the display panel 810, a gate printed circuit board 822 supplying a gate driving signal to the display panel 810, and A data driving circuit film 823 connecting the data printed circuit board 821 to the display panel 810 and a gate driving circuit film 824 connecting the gate printed circuit board 822 to the display panel 810. It includes. The data driving circuit film 823 and the gate driving circuit film 824 may include, for example, a tape carrier package (TCP) or a chip on film (COF). The gate printed circuit board 822 may be removed by forming separate signal wires on the display panel 810 and the gate driving circuit film 824.

On the other hand, the liquid crystal display according to another embodiment of the present invention further includes a power supply device 910 for generating a driving voltage for light emission of the light generating device 700. The driving voltage generated from the power supply 910 is applied to the light generating apparatuses 700 through the power line 912.

The liquid crystal display according to another exemplary embodiment of the present invention further includes a light guide plate 920 disposed on the light generating apparatuses 700. The light guide plate 920 is disposed at a spaced distance from the light generating apparatuses 700. The light guide plate 920 emits light close to white by mixing red light, blue light, and green light generated from the light generating apparatuses 700. The light guide plate 920 is formed of, for example, a poly methyl methacrylate (PMMA) material.

The LCD further includes an optical member 930 disposed on the light guide plate 920. The optical member 930 is disposed to be spaced apart from the light guide plate 920 by a predetermined distance or more to completely mix the red light, the blue light, and the green light. The optical member 930 includes an optical plate 932 for diffusing light emitted from the light guide plate 920 and an optical sheet 934 disposed on the optical plate 932.

The optical plate 932 diffuses the light emitted from the light guide plate 920 to improve the brightness uniformity of the light. The optical plate 932 has a plate shape having a predetermined thickness. For example, the optical plate 932 may be formed of a poly methyl methacrylate (PMMA) material, and may include a diffusing agent for diffusing light therein.

The optical sheet 934 changes the path of the light diffused through the optical plate 932 to improve the luminance characteristic of the light. The optical sheet 934 includes a light collecting sheet for condensing the light diffused through the optical plate 932 in the front direction to improve the front brightness of the light. The optical sheet 934 includes a diffusion sheet for diffusing the light diffused through the optical plate 932 once again.

On the other hand, the liquid crystal display device further includes an optical sheet having various functions according to the required brightness characteristics.

As described above, rounded prism-shaped convex lens array patterns are formed on the exit surface of the optical plate, so that light provided from the rear surface of the optical plate is scattered, thereby minimizing the generation of dark portions and bright lines, thereby improving light efficiency. Can be increased.

In addition, the light spacing between the light source and the optical plate may be reduced through light splitting by a more effective and optimized structure, thereby reducing the thickness of the backlight assembly and the liquid crystal display.

Although described above with reference to the embodiments, those skilled in the art can be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below. I can understand.

Claims (26)

Flat base portion; And And a plurality of rounded prisms formed on the flat plate base portion to improve uniformity of light passing through the flat plate base portion. The method of claim 1, wherein each of the prisms has a rounded vertex and two inclined portions connected to the vertex, The apex part disperses the back light having a predetermined pulse shape as the first diffused light, and the inclined part disperses the back light having a predetermined pulse shape as the second diffused light, The first diffused light has one peak value and is relatively smaller than the peak value of the back light, and the second diffused light has two peak values and is relatively smaller than the peak value of the back light and is relative to the peak value of the first diffused light. Optical plate, characterized in that small. The optical plate of claim 1, wherein the refractive index of the flat plate base portion is the same as that of the prism. The optical plate of claim 1, wherein the plate base portion has a thickness of about 1 mm to about 3 mm. The optical plate of claim 1, wherein an inclination angle of the prism is 43 degrees to 47 degrees. The optical plate of claim 1, wherein a radius of curvature of the apex of the prism and a length of the base of the prism are proportional to each other. The optical plate of claim 1, wherein the base length of the prism is 50 μm to 200 μm. The optical plate of claim 1, wherein a radius of curvature of the apex of the prism is 15 μm to 76 μm. The optical plate of claim 1, wherein a ratio of the base length of the prism to the radius of curvature of the rounded vertex of the prism is 100: 30 to 100: 38. The optical plate of claim 1 wherein each of the prisms is adjacent to each other. The optical plate of claim 1, wherein the prism has a height of 50 μm. The optical plate of claim 1, further comprising a UV light blocking coating layer formed on a rear surface of the flat plate base portion to block the high energy wavelength band of light provided from the rear surface from being applied to the flat plate base portion. . The optical plate of claim 1, further comprising UV light blocking particles formed on the flat plate base portion to block the high energy wavelength band of the light provided from the rear surface from being applied to the prisms. The optical plate of claim 1, wherein the flat plate base portion has scattering particles for scattering light. A light source unit for emitting light; And And a flat plate base portion, and a plurality of rounded prisms formed on the flat plate base portion, the optical plate for improving the uniformity of the light provided from the light source unit. The backlight assembly of claim 15, wherein the optical plate has heat resistance. The backlight assembly of claim 15, wherein the light source unit is a surface light source unit and the optical plate is spaced at least 6.5 mm from a relatively high surface of the surface light source unit. The backlight assembly of claim 15, wherein the light source unit is a plurality of lamps, and the optical plate is spaced at least 6.5 mm apart from an area corresponding to the lamps. The backlight assembly of claim 15, wherein an extension direction of the prisms is parallel to an array direction of the light source unit. The backlight assembly of claim 15, wherein a ratio of the base length of the prism to the radius of curvature of the rounded vertex of the prism is 100: 30 to 100: 38. A display panel which displays an image using light; A light source unit disposed under the display panel to emit light; And And a diffusing unit having a flat plate base portion and a plurality of rounded prisms formed on the flat plate base portion to improve uniformity of light provided from the light source unit and to emit the light. 22. The display device according to claim 21, wherein the light source unit is a flat fluorescent lamp disposed corresponding to the rear surface of the display panel. The display device of claim 21, wherein the light source unit comprises a plurality of lamps arranged corresponding to a rear surface of the display panel. The display device of claim 23, further comprising a reflector disposed under the lamp. The method of claim 21, wherein the diffusion unit, A transparent flat base portion; And And a plurality of rounded prisms formed on the flat base portion. The method of claim 21, wherein the diffusion unit, A transparent flat base portion; A lens array sheet having a plurality of rounded prisms formed to protrude convex; And And an adhesive member disposed between the flat plate base portion and the lens array sheet.

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