JP2001345009A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device wherein luminance is improved with a relatively simple structure and that is easily assembled. SOLUTION: In a light guide plate 2 having a flat-plate-shaped main body, a light incidence surface 21 is formed on four side end faces and a light emitting surface 22, on one face. Intermediate linear parts 41a, 42a of a pair of cold cathode fluorescent lamps 41, 42 which form a U-shape, are installed at first light incidence surfaces 21a, 21a so as to be opposed to each other. Both end linear parts 41b, 42b of the respective cold cathode fluorescent lamps 41, 42 are installed at the second light incident surfaces 21b, 21b. As the both end linear parts 41b, 42b of the cold cathode fluorescent lamps 41, 42 that are a pair of U-shaped light sources are respectively arranged on the second light incident surfaces 21b, 21b, two bulbs are substantially arranged on the second light incident surfaces 21b, 21b. On this account, the display device in which the amount of light entering into the light guide plate 2 can be increased can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a display device.

2. Description of the Related Art In a display device using a backlight, a sidelight type backlight is often used.
The sidelight method is to irradiate a display unit by making light incident from an end face of a light guide means such as a light guide plate, propagating incident light to one surface substantially orthogonal to the end surface, and emitting light from this one surface. is there.

[0002] Sidelight type backlights are becoming mainstream because the entire device can be made thinner than an internally illuminated type in which a light source is provided inside a display unit. Display devices tend to be required to have higher brightness as well as to reduce the thickness of the entire device.

[0003] For example, Japanese Patent Laid-Open No.
What is described in 232468 is known.
This conventional technique increases the amount of light incident on the light guide plate by providing a pair of L-shaped light sources so as to surround the periphery of the light guide plate and by providing a spot-like process for irregular reflection on the back side of the light guide plate. This is to improve brightness and prevent uneven brightness.

However, in the prior art, in order to further improve the brightness, it is necessary to increase the amount of light incident on the light guide plate per one L-shaped light source. The input power to the light source must be increased. However, if the input power is increased, a heavy load is applied to the light source, which causes problems such as shortening of the life of the light source. There is a limit to the amount of light incident on the light guide plate. In addition, since the L-shaped light sources are provided close to each other, if the electric polarities of the two light sources are different, the potential difference becomes high when the L-shaped light sources are turned on, and the adjacent L-shaped light sources are turned off. Special insulation had to be applied between the ends. Such an insulating process has a problem that the production becomes complicated and the cost increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a display device which has a relatively simple structure, improves luminance, and is easy to assemble.

According to a first aspect of the present invention, there is provided a display device having a main body having an opening and a lighting device housed therein; a rectangular flat main body, provided on one surface of the rectangular flat main body. A pair of first and second light-incident surfaces provided on an end surface substantially orthogonal to the light-exit surface and a light-exit surface facing the opening of the apparatus body. A light guide plate provided in the device main body so as to perform the operation; a display portion supported by the device main body so as to be positioned on the light exit surface side of the light guide plate; and a pair of bulbs bent in a U-shape. The intermediate linear portions of the bulbs are respectively disposed on the opposing first light incident surfaces, and the linear end portions of one bulb are disposed on the opposing second light incident surface together with the linear end portions of the other bulb. And a pair of light sources. It is set to.

In the present invention, definitions and technical meanings of terms are as follows unless otherwise specified.

The main body of the apparatus only needs to accommodate desired parts such as a lighting device for lighting a pair of light sources, which will be described later.
The shape, structure, material, and the like are not limited as long as an opening that accommodates the pair of light sources therein and is provided with a display unit described later is formed.

Further, the apparatus main body can be provided with a lamp holder, a lamp socket and the like in order to support the U-shaped light source at a predetermined position. It can also be arranged in. This reflecting section can be formed by whitening the inner surface of the apparatus main body, or a separate reflecting section may be arranged in the apparatus main body.

The light guide plate is desirably formed of a synthetic resin, such as an acrylic resin or a polycarbonate resin, but is not particularly limited as long as it has a property of transmitting incident light to an emission surface. The shape is desirably a flat plate, but any shape may be used as long as the gist of the present invention is not deviated.

The light guide plate allows the provision of light distribution means so as to obtain desired light distribution characteristics on the light exit surface.
As the light distribution means, for example, dot printing in which ink containing a light transmission control material (white pigment) is regularly printed on the surface facing the light emitting surface, and a plurality of irregularities are provided on the surface facing the light emitting surface Examples include, but are not limited to, a prism cut shape, a rough surface processing in which a surface facing a light emitting surface is polished to provide fine irregularities.

The light distribution means is provided in a desired pattern so as to obtain a desired light distribution. The light distribution means is not limited to the surface facing the light exit surface, and may be provided on both sides of the light exit surface of the light guide plate or the surface facing the light exit surface and the light exit surface. When a plurality of light guide plates are used, the same or different light distribution means can be provided for the plurality of light guide plates. The light distribution means may be formed directly on the light guide plate or may be formed separately. Therefore, an optical sheet having a condensing function or a light diffusing function may be provided on the light emitting surface, and in this case, the outer surface of the optical sheet constitutes the light emitting surface. Examples of the optical sheet include a sheet having a light collecting function provided with glass beads or the like, a prism sheet, a light diffusion sheet, a polarizing film, and the like.

The light guide plate may be provided with a reflection means on the surface opposite to the light exit surface. This reflecting means can be formed by sticking a silver sheet or a white resin sheet having a high reflectivity, or by applying a white pigment or the like to the light guiding means. Further, a reflector having a high reflectance may be provided separately from the light guide plate. In this case, the reflector provided in the apparatus main body described above may be used as the reflector. Further, it is also allowed that the reflecting means is provided with a process capable of printing a dot pattern or optically distributing light such as minute unevenness in the light emitting surface direction.

Further, it is also allowed to form a light guide plate by using a plurality of flat main bodies. For example, two light guide plates may be provided so as to overlap with each other so that a plurality of light exit surfaces are provided, and the respective light exit surfaces may be provided in directions different by 180 °.

The display section may be any display means such as a flat display panel having a light-transmitting property. The display section is illuminated with light emitted from the light exit surface of the light guide plate to display characters, designs, images or images. The display unit is provided with a display unit, and a display unit is formed by printing a desired paint on a translucent resin, glass, or the like, but the material and structure are not particularly limited.
In addition, those directly provided on the light guide plate are also allowed.

The display unit may be provided at a position protruding from the opening of the apparatus main body, or may be provided at a position substantially flush with the opening or at a position not protruding.

When a plurality of light guide plates are provided, the display section is provided for each light emitting surface.

The U-shaped light source is preferably a discharge lamp having electrodes at both ends, but the type of the light source is not particularly limited as long as it can be lit with a desired output by being supplied with power from both ends. Instead, an LED or the like may be used.

The "intermediate linear portion of the U-shaped light source" means one of the three sides forming the U-shape that has a bent portion on both sides and is not provided with an electrode portion. .

The pair of light sources are composed of bulbs bent in a U-shape, and are disposed on the first light incident surface such that the intermediate linear portions are opposed to each other. Are provided on the opposite second light incident surfaces together with the linear portions at both ends of the light source, so that the ends for electrical connection with the lighting device are provided apart from each other. Therefore, it is not necessary to perform a special insulation treatment or the like. In addition, since a pair of U-shaped light source ends having the electrode portions are provided apart from each other, the deformation or discoloration due to heat around the electrode portions due to the concentration of the mutually generated electrode portions, which has conventionally occurred, is provided. And the like can be reduced.

The linear portions at both ends of the pair of light sources may be provided so as to directly overlap each other, or may be provided between the overlapping U-shaped light sources via some member.

As the display device, a guide light, a guidance display board,
Examples include, but are not limited to, advertising lights and liquid crystal display devices.

In the display device, when the pair of light sources is turned on, light is incident on the light guide plate, and the light that has propagated inside the light guide plate is emitted from the light emission surface to illuminate the display unit.

According to the display device of the present invention, since the linear portions at both ends of the pair of light sources formed by the U-shaped bulbs are respectively disposed on the second light incident surface, the display device is provided on the second light incident surface. In this case, substantially two bulbs are provided, and the amount of light incident on the light guide plate can be increased.

Further, since the end portions of the pair of light sources are spaced apart from each other, complicated insulation treatment is not provided, wiring to the lighting device is facilitated, and a problem in the peripheral portion due to an increase in temperature at the end portions is prevented. Can be reduced.

According to a second aspect of the present invention, in the display device of the first aspect, the pair of light sources is arranged such that the linear relationship between the linear portions at both ends of one bulb and the linear portions at both ends of the other bulb is one. The second light incident surface and the second light incident surface are provided so as to be different from each other, and the intermediate straight portions of the pair of light sources are provided so as to intersect via the light guide plate.

The pair of light sources are not provided so as to overlap with each other. Instead, the one light-incident surface and the other second light-incident surface have linear portions at both ends of one bulb and the other bulb. It is provided so that the disposition relationship between the straight portions at both ends is different. In short, the intermediate straight portions of the pair of opposing bulbs are disposed so as to intersect with the light guide plate interposed therebetween.

Further, in the first or second aspect of the present invention, a heat radiating means capable of emitting heat from the pair of light sources may be provided. As this heat radiating means, it is preferable to provide a heat radiating means made of resin such as silicone rubber having thermal conductivity so as to be in contact with at least one of the electrodes of each of the pair of light sources. When the heat dissipating means is provided in this manner, the heat dissipating from the high temperature electrode is equally performed for both of the pair of light sources, so that it is possible to easily suppress a problem due to heat to the periphery of the electrode and to maintain the brightness uniformity. be able to.

According to a second aspect of the present invention, in the display device, the arrangement relationship between the linear portions at both ends of one bulb and the linear portions at both ends of the other bulb is such that one of the second light incident surfaces and the other of the second light incident surfaces. Are provided so as to be different from each other, and the intermediate straight portions of the pair of light sources are provided so as to intersect with each other via the light guide plate. Therefore, it is possible to easily suppress a problem due to a temperature rise of the electrode.

According to a third aspect of the present invention, in the display device according to the first or second aspect, the pair of light sources is a fluorescent lamp having a phosphor layer formed on the inner surface of the bulb.

As the pair of light sources, it is desirable to use a fluorescent lamp capable of efficiently obtaining a light output.

When a fluorescent lamp is used, a preferred fluorescent lamp is a glass tube as a bulb, a pair of electrodes sealed at both ends of the glass tube, a phosphor layer formed on the inner surface side of the glass tube, and sealed in the glass tube. And a discharge medium. Examples of the discharge medium include those composed of mercury and a rare gas, and those mainly composed of a rare gas such as xenon. When the electrode is a thin glass tube having a small tube diameter, a cold cathode is mainly used, but a hot cathode may be used. However, it is also possible to use electrodeless fluorescent lamps.

Also, the fluorescent lamp is allowed to be formed using external electrodes forming at least one electrode on the outer surface of the glass tube. When this external electrode type fluorescent lamp is used, it is preferable that the discharge medium is composed mainly of a rare gas, and when it is desired to intensively emit light from the glass tube in a specific direction, Forming a slit-like light guide for light guide along the longitudinal direction of the glass tube,
It is effective to form a reflective film on a portion other than the light guiding portion. When a rare gas generates ultraviolet rays by electric discharge such as xenon, a so-called aperture type and glass in which a phosphor layer that generates visible light when excited by ultraviolet rays is not formed in the light guide portion on the inner surface side of the glass tube or the like. It may be of any reflection type in which a phosphor layer is formed on the entire circumference of the tube and a reflection film is provided on a portion other than the light guide portion.

In the display device according to the third aspect, since the pair of light sources is a fluorescent lamp in which a phosphor layer is formed on the inner surface of the bulb, the luminance can be further improved.

According to a fourth aspect of the present invention, in the display device according to any one of the first to third aspects, the display unit is a liquid crystal display.

In the display device of the fourth aspect, since the liquid crystal display means is used in the display section, liquid crystal display can be performed.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an enlarged top view of a main part showing a light guide plate and a pair of light sources of a display device according to a first embodiment of the present invention.
FIG. 2 is an enlarged side view of a main part showing a display unit, a light guide plate, and a pair of light sources of the display device, and FIG. 3 is a partially cutaway top view of the display device with the display unit and a part of the device main body removed. is there.

In each of the figures, reference numeral 1 denotes an apparatus main body, 2 denotes a light guide plate, 3 denotes a liquid crystal panel as a display unit, and 41 and 42 denote cold cathode fluorescent lamps as U-shaped light sources.

The apparatus main body 1 is made of a synthetic resin having a high reflectance, has an opening (not shown) in a rectangular shape, and has an inner surface formed as a reflector having light reflection characteristics. A lighting device 11 is housed inside the apparatus main body 1 as shown in FIG.

The light guide plate 2 has a flat main body made of a transparent acrylic resin, and has first and second light incident surfaces 21a, 21a and 21a on the side end surfaces as shown in FIG.
A light incident surface 21 having b and 21b, and a light exit surface 22 is formed on one surface substantially orthogonal to the light incident surface 21. A light diffusion sheet (not shown) and a prism sheet (not shown) are attached to the light exit surface 22 for improving the luminance. On the surface opposite to the light exit surface 22, a plurality of uneven prism cuts (not shown) are formed in a desired pattern as luminance equalizing means.

The liquid crystal panel 3 has a pair of molecular alignment films (not shown) disposed between a pair of transparent electrodes (not shown) formed in a matrix. A liquid crystal (not shown) is disposed on the light guide panel 2 to form a liquid crystal panel 3. The liquid crystal panel 3 is disposed on the light emitting surface 22 side of the light guide plate 2 as shown in FIG.

The pair of cold cathode fluorescent lamps 41 and 42 has a U shape as shown in FIG.
The first and second intermediate linear portions 41a and 42a are provided on the first light incident surfaces 21a and 21a so as to face each other.
As shown in FIG. 1 or FIG.
The two linear portions 41b, 42b at both ends of each are provided on the second light incident surfaces 21b, 21b. The cold cathode fluorescent lamps 41 and 42 are supported by a lamp support member (not shown) made of a silicone resin having thermal conductivity.

Each of the cold cathode fluorescent lamps 41 and 42 has an electrode (not shown) at each end 43, and a wiring 4 for electrically connecting the end 43 to the lighting device 11.
4 are provided.

In the display device of the first embodiment, first, the cold cathode fluorescent lamps 41 and 42 are turned on by the lighting device 11.
The light emitted from the cold cathode fluorescent lamps 41 and 42 enters the four light incident surfaces 21 of the light guide plate 2, propagates through the light guide plate 2, and is emitted from the light emission surface 22 to irradiate the liquid crystal panel 3. And display.

In the display device of the first embodiment, linear portions 41b, 42b at both ends of cold cathode fluorescent lamps 41, 42, which are a pair of U-shaped light sources, are disposed on the second light incident surfaces 21b, 21b, respectively. Therefore, the second light incident surfaces 21b, 21b
Is provided with two bulbs, and the amount of light incident on the light guide plate 2 can be increased, so that the luminance can be improved.

Further, since the end portions 43 of the cold cathode fluorescent lamps 41 and 42 are provided apart from each other, a complicated insulating process is not provided, and the wiring to the lighting device 11 is facilitated.

Further, the cold cathode fluorescent lamps 41, 42
Since the end 43 is not provided adjacently, it is possible to prevent the peripheral portion from being inconvenienced due to a local temperature rise, and since the heat is dispersed by the lamp support member having thermal conductivity, the end 43 Temperature rise is suppressed.

Next, a second embodiment will be described.

FIG. 4 is a partially cutaway top view of a display device according to a second embodiment of the present invention, in which a display portion and a part of the device main body are removed, and FIG. 5 is a view similarly viewed from the direction A in FIG. FIG. 6 is an enlarged side view of a main part showing a display unit, a light guide plate, and a pair of light sources of the device. FIG. 6 is an enlarged side view of a main part showing the display unit, the light guide plate, and the pair of light sources of the display device, also viewed from the direction B in FIG. FIG.

In each figure, reference numeral 50 denotes a silicone rubber as a heat radiating means, and 51 denotes a heat radiating plate.

The pair of cold-cathode fluorescent lamps 41, 42 are such that, on the light incident surface 21b shown in FIG. The linear portion 42b is provided on the heat sink 51 side. Further, on the light incident surface 21a shown in FIG. 6, the intermediate straight portion 41a of the cold cathode fluorescent lamp 41 is provided so as to extend from the liquid crystal panel 3 toward the heat sink 51. Further, as shown in FIG. 4, the pair of cold cathode fluorescent lamps 41, 42 has a second light incident surface 21b, in which a linear portion at both ends of one bulb and a linear portion at both ends of the other bulb are arranged. It is provided so that the installation relationship is upside down. In short, the cold cathode fluorescent lamps 41 and 42 are provided so as to be twisted with each other.

The end portions 4 of the cold cathode fluorescent lamps 41 and 42
3 is supported by a silicone rubber 50 having thermal conductivity. The electrode grounded to the silicone rubber 50 is a ground-side electrode.

The silicone rubber 50 is provided on the heat radiating plate 51. The radiator plate 51 is made of a metal having a high thermal conductivity.

In the display device of the second embodiment, the arrangement relationship between the linear portions 41b at both ends of the bulb of the cold cathode fluorescent lamp 41 and the linear portions 42b at both ends of the bulb of the cold cathode fluorescent lamp 42 is such that one of the second light incident portions. The surface 21b and the other second light incident surface 21b
Are provided differently from each other, and the silicone rubber 5
Since heat is dissipated by 0, it is possible to easily suppress a problem due to an increase in the temperature of the electrode.

[0053]

According to the first aspect of the present invention, since the linear portions at both ends of the pair of light sources formed by the U-shaped bulbs are respectively disposed on the second light incident surfaces, the second light source is provided. Since substantially two bulbs are provided on the incident surface, it is possible to provide a display device capable of increasing the amount of light incident on the light guide plate.

Further, since the end portions of the pair of light sources are spaced apart from each other, complicated insulation treatment is not provided, and wiring to the lighting device is facilitated. A display device that can be reduced can be provided.

According to the second aspect of the present invention, the disposition relationship between the linear portions at both ends of one valve and the linear portions at both ends of the other valve is as follows.
Since the one second light incident surface and the other second light incident surface are provided so as to be different from each other, and the intermediate straight portions of the pair of light sources are provided so as to intersect via the light guide plate, the electrode A display device that can easily suppress the trouble due to the temperature rise of the display device.

According to the third aspect of the present invention, the pair of light sources
Since the fluorescent lamp has the phosphor layer formed on the inner surface of the bulb, it is possible to provide a display device capable of further improving luminance.

According to the fourth aspect of the present invention, since the liquid crystal display means is used in the display section, it is possible to provide a display device capable of performing liquid crystal display.

[Brief description of the drawings]

FIG. 1 is an enlarged top view of a main part of a display device according to a first embodiment of the present invention.

FIG. 2 is an enlarged side view of a main part of the display device.

FIG. 3 is a partially cutaway top view of the display device with a part removed.

FIG. 4 is a partially cut-away upper surface from which a part of the display device according to the second embodiment of the present invention is removed.

FIG. 5 is an enlarged side view of a main part of the display device as viewed from a direction A of the display device.

FIG. 6 is an enlarged side view of a main part of the display device as viewed from a direction B of the display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Device main body, 2 ... Light guide plate, 3 ... Liquid crystal panel which is a display part, 41, 42 ... Cold cathode fluorescent lamp,

Claims (4)

[Claims] An apparatus body having an opening and a lighting device housed therein; a rectangular flat body; a light emitting surface provided on one surface of the rectangular flat body; and substantially orthogonal to the light emitting surface. A light guide plate having first and second light incident surfaces, which are provided on an end surface thereof, and which are opposed to each other, and provided in the device main body such that a light emitting surface faces an opening of the device main body; A display portion supported by the device main body so as to be positioned on the light exit surface side of the light guide plate; and a first light having a pair of bulbs bent in a U-shape, and an intermediate straight portion of the bulbs facing each other. A pair of light sources provided on the incident surface, and provided on a second light incident surface in which the linear portions at both ends of one bulb are opposed to the linear portions at both ends of the other bulb;
A display device comprising: 2. A pair of light sources, wherein the arrangement relationship between the linear portions at both ends of one bulb and the linear portions at both ends of the other bulb is different between the one second light incident surface and the other second light incident surface. The display device according to claim 1, wherein the display device is provided so as to be different, and is provided so that an intermediate straight portion of the pair of light sources intersects via a light guide plate. 3. The display device according to claim 1, wherein the pair of light sources is a fluorescent lamp having a fluorescent layer formed on the inner surface of the bulb. 4. The display device according to claim 1, wherein the display unit is a liquid crystal display.