JP4767427B2 - Illumination device, liquid crystal display device and apparatus incorporating the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lighting device used for a liquid crystal display device of a device such as a mobile phone or a portable information terminal such as a pocket PC, a liquid crystal display device using the lighting device, and a device incorporating the same.
[0002]
[Prior art]
Liquid crystal display devices are widely used from large devices such as word processors and personal computers to small devices such as mobile phones and portable information terminals, which are various information devices that have recently been remarkably developed. FIG. 9 is a schematic perspective view showing the arrangement of a light guide and a light source in an illuminating device that is incorporated in a mobile phone device and illuminates a liquid crystal display element from the back, and FIG. 10 uses the light guide and the light source of FIG. Sectional drawing which showed the outline of the illuminating device and the liquid crystal display device which uses this is shown.
[0003]
In the figure, 25 is a light guide made of a translucent resin material, 26 is a main light emitting portion in the light guide for illuminating the liquid crystal display element 32 from the back, and 27 is integrally formed with the main light emitting portion 26. Sub-light emitting portions in the light guides provided in series, 4 and 5 are parts, for example, a hole from which a switch button in which a call switch for a telephone number, an incoming call history switch and the like is arranged, 6 is a switch for a menu button and an electric A hole in which the circuit portion is provided, 8, 9, and 10 are light sources such as LEDs and small incandescent lamps arranged close to one side surface of the light guide, and 28 is a light emission of the main light emitting portion 26. A main light emitting surface that is effectively used on the upper surface, 29 is a light control member for restricting the direction of light disposed on the upper surface of the main light emitting portion 26, and 30 is disposed on the lower surface side of the light guide 25. Passes through the lower surface of the main light emitting part 26 and the sub-light emitting part 27 Light reflecting plate for the light incident again to the main light-emitting unit 26 and the sub-light emitting unit 27 of light was 31 is a mounting substrate which light source or other circuit components necessary are mounted.
[0004]
A known dot pattern printing or projection is provided on the lower surface of the main light emitting portion 26 of the light guide 25 in order to emit light from the light source incident on the light guide to the entire light guide as much as possible with uniform luminance. It is applied to the entire lower surface. Further, the light control member 29 may be a light diffusing plate alone or may be configured by superposing a light diffusing plate and a prism sheet. Furthermore, a known liquid crystal display element 32 is arranged on the upper surface of the light control member 29 to constitute a liquid crystal display device. When the apparatus is incorporated into an actual device, a light reflector or light reflector is used as a light source so as to surround the light source so that the light of the light sources 8, 9, and 10 is effectively incident on the light guide 25. It is arranged around.
[0005]
When the light sources 8, 9, and 10 of the lighting device having such a configuration are turned on, the light is incident from one side surface of the light guide 25 and guided through the light guide toward the other side surface. Light having a relatively high luminance is emitted from the upper surface 28 of the main light emitting portion 26 of the light guide 25 while light that has passed through the lower surface of the light guide is again incident on the light guide. The direction of light is controlled by the control member 29 and light is emitted from the upper surface of the light control member 29. This light is used to illuminate the liquid crystal display element 32 from the back and recognize images and information by the liquid crystal display element.
[0006]
Further, the light guided through the light guide 25 is also guided to the sub-light emitting unit 27, and the light emitted from the sub-light emitting unit 27 by this light guide is not sufficient as compared with the luminance of the main light emitting unit 26. However, there is no problem in practical use, and for example, the switch and the vicinity thereof, which are parts protruding the holes 4, 5, and 6, are also illuminated.
[0007]
[Problems to be solved by the invention]
The light from the upper surface 28 of the main light emitting unit 26 for illuminating the liquid crystal display element from the back is difficult to clearly recognize the reproduced image and information of the liquid crystal display element unless the luminance is sufficient. Dot pattern printing and protrusions are applied to the lower surface of the light source so as to obtain as uniform and bright brightness as possible. However, the brightness is inevitably lowered as the distance from the vicinity of the side surface of the light guide where the light sources 8, 9, and 10 are arranged. In particular, the farthest X portion in the main light emitting portion 26 that is separated from the light source is slightly lower in luminance than the vicinity of the light source, although there is no practical problem.
[0008]
Accordingly, an object of the present invention is to provide an illuminating device that solves such problems and has increased light emission luminance from the upper surface of the main light emitting portion, and a liquid crystal display device and equipment using the same.
[0009]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided an illuminating device comprising: a light guide composed of a main light emitting portion and a sub-light emitting portion connected to the main light emitting portion; a light control member, and the light reflecting plate disposed on the light guide downwardly, in the lighting device including at least one light source is arranged close to the side of the main light emitting portion of the light guide, the A light reflecting groove for reflecting light in the direction of the main light emitting part and a light passing part for making light incident on the auxiliary light emitting part are provided. The brightness of the farthest portion of the main light emitting portion that is further apart can be increased.
[0010]
The illumination device according to claim 2 of the present invention uses an LED as a light source, and the LED can be used sufficiently as a light source of the illumination device.
[0011]
In the illumination device according to claim 3 of the present invention, the light reflecting groove is provided at the boundary portion between the main light emitting portion and the sub light emitting portion, and the arrangement of the boundary portion is suitable for the light reflecting groove. The brightness of the farthest part of the main light emitting part that is separated from the light source can be increased by the light reflection of the light reflecting groove.
[0012]
The illumination device according to claim 4 of the present invention includes a light reflecting member having a fitting portion that fits into the light reflecting groove and having a light reflecting layer on a surface facing the main light emitting portion. Thus, the luminance of the farthest portion of the main light emitting portion that is further away from the light source can be further increased.
[0013]
The illumination device according to claim 5 of the present invention includes a light reflecting member that is formed of a material having good light reflection efficiency and has a fitting portion that fits into the light reflecting groove. By using the reflecting member, it is possible to further increase the luminance of the farthest portion of the main light emitting portion that is separated from the light source without providing a light reflecting layer.
[0014]
The illumination device according to claim 6 of the present invention includes a light incident portion that causes light emission of the light source to be incident on a side surface of the main light emitting portion of the light guide opposed to the light source, and the light incident portion includes: The light guide body has a height dimension shorter than the length in the thickness direction of the light guide body, and includes a recess provided in the light reflection groove direction from the side surface, and a bottom surface portion connected to the recess. Then, by removing the shadow in the vicinity of the light source, it is possible to increase the luminance of the distant portion of the main light emitting portion that is free from luminance unevenness and is separated from the light source.
[0015]
According to a seventh aspect of the present invention, a liquid crystal display element is arranged on the upper surface of the light control member of the lighting device according to any one of the first to sixth aspects. A liquid crystal display device capable of clearly confirming recognition can be provided.
[0016]
According to the eighth aspect of the present invention, the liquid crystal display device according to the seventh aspect is incorporated, and it is possible to provide a highly convenient device capable of clearly reproducing the image display on the device.
[0017]
According to the ninth aspect of the present invention, the device is a mobile phone, and a small mobile phone excellent in image recognition can be provided.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a perspective view showing the arrangement of a light guide and a light source in the illumination device of the present invention, FIG. 2 is a plan view showing the relative arrangement relationship thereof, and FIG. 3 is a longitudinal sectional view taken along line AA in FIG. 1 is a light guide, 2 is a main light emitting part of the light guide, 3 is a sub-light emitting part integrally connected to the main light emitting part 2, 4, 5, and 6 are described above. For example, a hole for projecting a switch or the like as a component, 7 is a light reflecting groove provided at a boundary portion between the main light emitting portion 2 and the sub light emitting portion 3, and 8, 9 and 10 are the above-described LEDs and small incandescent lights. A light source 11 such as a light bulb 11 is an upper surface of the main light emitting portion where the light emitted from the main light emitting portion 2 is effectively utilized.
[0019]
The light guide and the light source are combined with a light control member 29 and a light reflection plate 30 shown in FIG. 10 to form an illumination device, and a liquid crystal display element 32 is disposed on the upper surface of the light control member. A liquid crystal display device can be configured.
[0020]
Now, when the light sources 8, 9, and 10 constituting such an illumination device are turned on, the light emission is incident from one side surface of the light guide 1 and is guided through the inside of the light guide 1 as described above. At the same time, the light passing through the lower surface of the light guide is reflected by the light reflecting plate 30 shown in FIG. 10, and light having sufficiently high luminance is emitted from the upper surface 11 of the main light emitting portion 2, and the main light emitting portion. The light that has passed through 2 is also guided to the auxiliary light emitting unit 3 to illuminate the vicinity of a switch (not shown) disposed in the holes 4, 5, 6. At least a part of the light that passes through the main light emitting part 2 and is incident on the sub light emitting part 3 is reflected by the light reflecting groove 7 and re-enters the main light emitting part 2, and the upper surface of the main light emitting part 2. More light is emitted, and the luminance of the emitted light in the X portion of the upper surface 11 becomes brighter.
[0021]
Further, the light that has passed through the light reflecting groove 7 and the light incident on the sub light emitting portion 3 without being blocked by the light reflecting groove 7 are near the holes 4, 5, 6 provided in the sub light emitting portion 3. Light is emitted upward, and the display of information such as the arrangement position of parts such as switches and other buttons and information can be illuminated.
[0022]
As described above, since the luminance of the emitted light of the X portion located far from the light source arrangement portion of the upper surface 11 of the main light emitting portion 2 can be increased, a liquid crystal is formed on the upper surface of the illumination device as shown in FIG. By disposing the display element 32, a reproduced image by the liquid crystal display element 32 can be viewed brightly and clearly. The light reflecting groove 7 preferably has a width that does not block light incident on the sub-light emitting portion 3 from blocking incident light on the holes 4 and 5.
[0023]
FIG. 4 is a perspective view partially showing only the part different from the first embodiment of the lighting device according to the second embodiment of the present invention, and this embodiment can be fitted into the light reflecting groove 7. A light reflecting member 12 made of a translucent material is attached, and the light reflecting member 12 is a T-shaped fitting portion that fits into the light reflecting groove 7 as shown in the enlarged perspective view of FIG. 13 and an upper lid portion 14, and a light reflecting layer coated with a milky white light reflecting material is formed on the surface 15 of the fitting portion 13 facing the main light emitting portion to increase the light reflecting efficiency. Thus, more light than in the previous embodiment can be reflected by the main light emitting portion 3, and the luminance of the X portion of the upper surface 11 of the main light emitting portion 3 can be further increased. Further, the light reflecting member 12 is made of a milky white resin material having a relatively high light reflecting efficiency, so that it is not necessary to provide a light reflecting layer on the surface 15.
[0024]
FIG. 6 is a perspective view of a light guide body in which only a portion different from the previous embodiment is shown in the third embodiment of the illumination device of the present invention. In this embodiment, the light sources 8, 9, and 10 are opposed to each other. The light incident portions 16, 17, 18 that are arc-shaped depressions are provided in the range from the upper surface position of the light guide body to the middle of the side surface height toward the lower surface direction at the position of the side surface portion of the light guide body 1. is there. By providing such a light incident portion, in the conventional device shown in FIG. 9, shadows as shown in the figure are generated between the light sources near the side surface of the light guide and at the end portions of the light sources 8 and 10. Although unevenness in luminance occurs in the vicinity of the light source of the light emitting unit 26, by providing the light incident units 16, 17, and 18, the problem of shading can be improved without reducing the light emitting luminance from the main light emitting unit. it can. That is, in order to improve the shadow in the vicinity of the light source, as shown in FIG. 11, arc-shaped depressions 33, 34, 35 are provided from the upper surface of the side surface to the lower surface at the side surface facing the light source of the light guide 36. However, there is a problem that the luminance of the emitted light from the main light emitting portion of the light guide is lowered, although the above-described generation of shadows in the vicinity of the light source can be improved. In order to solve such a problem, by providing the light incident portion as in the present embodiment, it is possible to suppress the occurrence of shadows in the vicinity of the light source without reducing the luminance from the main light emitting portion.
[0025]
7 and 8 are not the light incident portions of the arc-shaped depressions shown in the embodiment of FIG. 6, but the depressions are made into light incident portions of triangular shapes 19, 20, 21 and trapezoidal shapes 22, 23, 24. Even in such a shape, it is possible to eliminate the occurrence of shadows between the light sources and the end portions of the light sources without reducing the luminance from the main light emitting portion as in the case of the arc shape.
[0026]
As shown in FIG. 10, the light guide and the light source are arranged as a light reflector, a light control member, etc. to complete the lighting device, and a liquid crystal display element is placed on the upper surface of the light control member. By doing so, a liquid crystal display device can be configured, and a liquid crystal display device capable of recognizing a clear image under illumination with sufficient luminance can be provided. Further, a cellular phone, an information terminal, etc. incorporating this liquid crystal display device can be provided. This makes it possible to improve the visibility of the reproduced image and information of the device, and to facilitate the operation of the device by the emitted light from the sub-light emitting portion, thereby simplifying the operation.
[0027]
Furthermore, in the above-described embodiment, the light reflection groove penetrates the light guide, but may be provided in a range from the upper surface to the lower surface of the light guide.
[0028]
【The invention's effect】
As described above, the illuminating device of the present invention has a light reflection groove for reflecting at least a part of the light incident on the sub-light emitting part in the direction of the main light emitting part. Since it is provided, it is possible to increase the luminance of the emitted light from the light emitting portion at a distant position away from the light source of the main light emitting portion. Further, when a light reflecting member that fits into the light reflecting groove is provided, the luminance of the emitted light of the light emitting portion located farther from the light source of the main light emitting portion can be further increased.
[0029]
Furthermore, since the light incident part that can remove the shadow generated between the light sources and the light source end side without reducing the luminance of the main light emitting part is provided on the side part of the light guide facing the light source. By using the illumination device, the reproduced image on the liquid crystal display device can be clearly recognized without any shadow and with sufficient luminance. Naturally, a device incorporating this liquid crystal display device, such as a mobile phone or an information terminal, can be made more convenient.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing an arrangement of a light guide and a light source in the lighting device according to the first embodiment of the present invention. FIG. 2 shows a relative arrangement relationship between the light guide and the light source according to FIG. FIG. 3 is a longitudinal sectional view taken along line AA of the perspective view of FIG. 1. FIG. 4 is a partial perspective view of a light guide in an illumination device according to a second embodiment of the present invention. Fig. 6 is an enlarged perspective view of a light reflecting member of an embodiment according to Fig. 4. Fig. 6 is a partial perspective view of a light guide in an illuminating device according to a third embodiment of the invention. Fig. 7 is a fourth embodiment of the invention. FIG. 8 is a plan view partially showing a light guide in a lighting device. FIG. 8 is a plan view partially showing a light guide in a lighting device according to a fifth embodiment of the present invention. FIG. 10 is a schematic perspective view showing the arrangement of light guides and light sources in the device. FIG. 10 is a schematic view of an illumination device and a liquid crystal display device using the illumination device. Sectional view 11 partial perspective view of the light guide of the conventional lighting device [Description of symbols]
DESCRIPTION OF SYMBOLS 1 Light guide 2 Main light emission part 3 Sublight emission part 4, 5, 6 Hole 7 Light reflection groove 8, 9, 10 Light source 11 Upper surface 12 Light reflection member 13 Fitting part 16, 17, 18, 19, 20, 21, 22, 23, 24 Light incident portion 29 Light control member 30 Light reflection plate 31 Mounting substrate 32 Liquid crystal display element

Claims (9)

A light guide made up of a main light emitting part and a sub light emitting part connected thereto, a light control member arranged above the light guide for controlling the light direction, and arranged below the light guide. Light for reflecting light in the direction of the main light emitting portion in an illuminating device comprising: a light reflecting plate; and at least one light source disposed in proximity to a side surface of the main light emitting portion of the light guide. An illumination device, comprising: a reflection groove and a light passage portion for allowing light to enter the auxiliary light emitting portion. The lighting device according to claim 1, wherein the light source is an LED. The lighting device according to claim 1, wherein the light reflection groove is provided at a boundary portion between the main light emitting portion and the sub light emitting portion. The lighting device according to claim 1, further comprising: a light reflecting member having a fitting portion that fits into the light reflecting groove and having a light reflecting layer on a surface facing the main light emitting portion. The lighting device according to claim 1, further comprising a light reflecting member that is formed of a material having high light reflection efficiency and has a fitting portion that fits into the light reflecting groove. A light incident part for making light emitted from the light source incident on the side surface of the main light emitting part opposed to the light source, wherein the light incident part has a height dimension shorter than the length of the side surface of the light guide in the thickness direction. The lighting device according to claim 1, comprising: a recess provided in the light reflection groove direction from the side surface; and a bottom surface portion connected to the recess. A liquid crystal display device comprising a liquid crystal display element disposed on the upper surface of the light control member of the lighting device according to claim 1. A device incorporating the liquid crystal display device according to claim 7. The device according to claim 8, wherein the device is a mobile phone.

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