JPH058542U - LCD lighting device - Google Patents

Abstract

(57) [Abstract] [Purpose] To make a liquid crystal lighting device thin while keeping the brightness constant. A recess 15 for burying the liquid crystal display plate X and the pixel driving element 10b is formed on the front surface of the light guide plate 11 so that the area of the light incident end face of the light guide plate 11 is not reduced. Also, the pixel driving element 10b and the like are prevented from protruding forward from the light guide plate 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

  The present invention is an object used for back lighting of a light receiving liquid crystal display device. The present invention relates to a jilite type lighting device.

[0002]

[Prior art]

  Conventionally, as an edge light type illumination device as a liquid crystal display device, FIG. As described above, a lamp such as a cold cathode tube or a hot cathode tube is used as the light source 1, and this is a transparent material. It is arranged on both sides of the light guide plate 2 made of material, and the brightness of the illumination surface is spread over the entire surface of the light guide plate 2. Diffusion sheet consisting of milky white synthetic resin plate with light scattering effect for uniformization The sheet 3 is provided, and the reflection sheet 4 is a specular reflector or a light scattering acrylic. Plates and the like are used. This reflection sheet 4 reflects the light emitted from the light source and traveling toward the back surface. Provided to improve the light utilization efficiency by shining and guiding it to the front Is. Then, use this lighting device at a distance of about 0.5 mm behind the liquid crystal display panel X. I was offering

[0003]   Here, especially in the field of color LCD unit panels, the optical It is indispensable to stack the polarizing plates by utilizing the opposite isomers. About 50% will be cut. Therefore, it has low power consumption and high brightness. The market needs to be a clear lighting unit and a thin LCD unit. Then there is a strong demand.

[0004]   In FIG. 5, 7 is a light source reflection that reflects the light from the light source to the outside toward the light guide plate 2 side. A body (reflector) 8 is a pixel driving element (PWB: which drives pixels of the liquid crystal display panel X). Printed wiring board), 9 is a circuit for connecting the liquid crystal display panel X and the pixel drive element 8. It is a connected body by automated bonding (TAB).

[0005]

[Problems to be solved by the device]   Edge light method in which light is made incident from the light incident end surfaces 5 at the left and right ends of the conventional light guide plate 2. Type illuminators can achieve a very uniform brightness distribution, but generally the light utilization efficiency is The rate is low. To solve this problem, the diffusion power should be kept constant under the condition of low power consumption of about 5W. In order to realize the light brightness on the light guide 3, the area of the light incident surface of the light guide plate 2, that is, the light guide surface It is also conceivable to increase the thickness of the plate 2. But then, realization of thinning From this standpoint, we will not match market needs, especially color L It was a problem in the field of CD units.

[0006]   SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a lighting device with high brightness and thinness. With the goal.

[0007]

[Means for Solving the Problems]

  The problem solving means according to claim 1 of the present invention is as shown in FIGS. And is arranged in parallel with the liquid crystal display panel X behind the liquid crystal display panel X. Illumination for liquid crystal provided with a light guide plate 11 and a light source 12 arranged at an end of the light guide plate 11. In the device, the liquid crystal display panel X is embedded in the front surface of the light guide plate 11. The recess 15 is formed.

[0008]   The problem solving means according to claim 2 of the present invention is the liquid crystal display panel X according to claim 1. The pixel driving element 10a for driving the pixels of the liquid crystal display panel X is provided, and The driving element burying portion 1 for burying the pixel driving element 10a in the recess 15 of 6a is formed.

[0009]

[Action]

  In the problem solving means according to claims 1 and 2, the concave portion 15 is provided on the front surface of the light guide plate 11. Then, the liquid crystal display panel X and the pixel driving element 10 a are embedded in the recess 15. This As a result, the liquid crystal display panel X and the pixel driving element 10a are connected to the light guide plate 1 of the liquid crystal lighting device. It is prevented from protruding forward from 1.

[0010]

【Example】

(First embodiment)   FIG. 1 is a sectional view of a liquid crystal lighting device showing a first embodiment of the present invention, and FIG. FIG. 3 is a perspective view of a liquid crystal display panel X used in a lighting device for a vehicle.

[0011]   First, the liquid crystal display panel X handled by the liquid crystal lighting device of this embodiment will be described. . The liquid crystal display panel X is a color LCD having a thickness of 1.7 mm as shown in FIGS. Around it, as shown in FIG. 2, a pixel drive element 10a for driving the pixels of the liquid crystal display panel X. A printed wiring board 10b (PWB) having an (IC chip) is provided. The liquid crystal display board X and the printed wiring board 10b are tape automated bonds. They are connected to each other by a connecting body 10c by daiing (TAB).

[0012]   Next, the liquid crystal lighting device of the present embodiment will be described. The liquid crystal lighting device is 1, the liquid crystal display panel X is illuminated from the rear by the edge light method. The light guide plate 11 arranged parallel to the liquid crystal display plate X and the light from both ends of the light guide plate 11 A pair of light sources 12 for irradiating the incident end face 11a with light and a light source arranged on the rear portion of the light guide plate 11. A reflection sheet 13 for reflecting the backward light in the light guide plate 11 to the liquid crystal display panel X side; , Which is disposed in the front part of the light guide plate 11 and spreads the forward light in the light guide plate 11 to the liquid crystal display plate X. And a diffusing sheet 14 that scatters.

[0013]   As shown in FIG. 1, the light guide plate 11 is injection-molded using an acrylic resin or the like and has a thickness of It is formed in a flat plate shape having a size of 6 mm. The end face of the light guide plate 11 is a light incident end face 11a. It is said that.

[0014]   Then, the liquid crystal display panel X and the diffusion sheet 14 are provided on the front surface of the light guide plate 11. A recess 15 for burying is formed.

[0015]   The concave portion 15 is formed so as not to reduce the area of the light incident end surface 11a of the light guide plate 11. It is arranged apart from the section. The recess 15 is a first part for burying the liquid crystal display panel X. The step portion 16 and the second step portion 17 in which the diffusion sheet 14 is buried behind the first step portion 16. Consists of.

[0016]   The depth dimension of the first step portion 16 corresponds to the thickness dimension of the liquid crystal display panel X 1. It is set to 7 mm. The pixel driving elements of the liquid crystal display panel X are provided at both ends of the first step portion 16. Buried portion 1 for drive element for burying printed wiring board 10b including child 10a 6a is formed.

[0017]   The depth dimension of the second step portion 17 is such that the diffusion sheet 14 and the liquid crystal display panel X are separated from each other. In order to have a light-scattering property, a margin is provided more than the thickness of the diffusion sheet 14 described later. It is set, and is specifically set to 0.5 mm.

[0018]   Each of the light sources 12 includes a light-emitting body such as a filament and an outer tube that covers the light-emitting body. For example, a straight tube type cold cathode tube (CCFT) is used, and its diameter is 4. The brightness is set to 1 mm, the tube brightness is set to 15000 ut, and the power consumption is set to 5 W.

[0019]   The reflective sheet 13 is a 0.18 mm thick existing specular reflector or light scattering acrylic. Plates are used.

[0020]   The diffusion sheet 14 has a milky white color of the same shape as the second step portion 17 and has a thickness of 0.25 mm. Is a synthetic resin plate of, and is separated from the liquid crystal display panel X by 0.5 to 2 mm on the bottom surface of the second step portion 17. They are arranged closely together.

[0021]   In the figure, 21 is a 0.1 mm thick metal plate having a high reflection efficiency, and the central portion is C-shaped in section. It is a light source reflector (reflector) bent into a shape.

[0022]   The lighting device having the above configuration is manufactured as follows. First, regarding the light guide plate 11, Acrylic resin is poured into a mold and cured to mold. At this time, on the front surface of the light guide plate 11. The concave portion 15 including the first step portion 16 and the second step portion 17 is formed.

[0023]   After that, the reflection sheet 13 is closely attached to the rear surface of the light guide plate 11, and The diffusion sheet 14 is brought into close contact with the bottom surface of the second step portion 17 of No. 1. After that, the pair of light sources 1 2 is arranged with the light guide plate 11 interposed therebetween, and the lighting device is completed.

[0024]   Further, when the liquid crystal display panel X is attached, the liquid crystal display panel X and the pixel driving element 10 are The printed wiring board 10b including a is embedded in the first step portion 16 of the recess 15. so Then, the printed wiring board 10b including the liquid crystal display panel X and the pixel driving element 10a. Can be prevented from protruding forward from the light guide plate 11 of the liquid crystal lighting device. The thickness can be reduced by 1.7 mm.

[0025]   Next, the operation when the lighting device is used will be described. Light from the light source 12 is transmitted through the light guide plate 11 From the light incident end face 11a of the above. After that, incoming light diffuses from the front Through the sheet 14, the light uniformly distributed is applied to the back surface of the liquid crystal display panel.

[0026]   At this time, since the recess 15 is arranged apart from the end surface of the light guide plate 11, The area of the shooting end surface 11a can be made to have the same dimension as the conventional one. Therefore, liquid crystal display Even when the plate X is embedded in the light guide plate 11 to achieve a thin structure, the amount of incident light is reduced. Can be prevented.

[0027]   In this embodiment, specifically, the brightness of 1800 ut is actually measured on the diffusion sheet 14. Revealed. Especially in the field of color LCD units, high brightness backlight devices. The liquid crystal display unit can be made thinner while maintaining the same characteristics as before. The effect is great.

[0028]   (Second embodiment)   FIG. 3 is a sectional view of a liquid crystal lighting device showing a second embodiment of the present invention. As shown In the liquid crystal lighting device of this embodiment, the rear surface of the light guide plate 11 has an arcuate shape. That is, the lighting device for liquid crystal is made lighter.

[0029]   Also in this embodiment, the same effect as the first embodiment can be obtained.

[0030]   (Third embodiment)   FIG. 4 is a sectional view of a liquid crystal lighting device showing a third embodiment of the present invention. As shown In the liquid crystal lighting device of the present embodiment, a large number of recesses 22 are formed on the rear surface of the light guide plate 11, The light in the light guide plate 11 is emitted perpendicularly to the liquid crystal display plate so as to increase the brightness of the illumination surface. It is composed.

[0031]   Also in this embodiment, the same effect as the first embodiment can be obtained.

[0032]   It should be noted that the present invention is not limited to the above-mentioned embodiment, but may be applied within the scope of the present invention. Of course, many modifications and changes can be made to the embodiments.

[0033]   For example, although the light source 12 is arranged on both sides of the light guide plate 11 in each of the above embodiments, It may be arranged only in the.

Further, the rear surface of the light guide plate 11, that is, the reflection surface may have a structure in which particles such as glass beads are put in a white pigment such as BaSO ₄ or TiO ₂ to increase the scattering effect.

[0035]

[Effect of device]

  As is clear from the above description, according to claims 1 and 2 of the present invention, the front surface of the light guide plate is Since the concave portion for burying the liquid crystal display plate and the pixel driving element is formed, The liquid crystal display panel and the pixel driving element protrude forward from the light guide plate of the liquid crystal lighting device. Of the liquid crystal lighting device without reducing the area of the light incident end surface of the light guide plate. If it can be realized, it has an excellent effect.

[Brief description of drawings]

FIG. 1 is a sectional view of a liquid crystal lighting device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a liquid crystal display plate which is also used in the liquid crystal lighting device.

FIG. 3 is a sectional view of a liquid crystal lighting device showing a third embodiment of the present invention.

FIG. 4 is a sectional view of a liquid crystal lighting device according to a fourth embodiment of the present invention.

FIG. 5 is a cross-sectional view of a conventional liquid crystal lighting device.

[Explanation of symbols]

10 Light guide plate 12 light sources 13 Reflective sheet 14 Diffusion sheet 15 recess

Claims (2)

[Scope of utility model registration request] 1. A light source for illuminating from behind a liquid crystal display plate, the light guide plate being arranged in parallel with the liquid crystal display plate behind the liquid crystal display plate, and a light source arranged at an end of the light guide plate. In a liquid crystal lighting device provided with the liquid crystal lighting device, a concave portion for burying the liquid crystal display plate is formed in a front surface of the light guide plate. 2. The liquid crystal display panel according to claim 1, further comprising a pixel driving element for driving pixels of the liquid crystal display panel.
An illuminating device for liquid crystal, wherein a recessed portion for a drive element for burying the pixel drive element is formed in the recessed portion.