JP2000214462A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal display device including an illuminating device which can control the chromaticity. SOLUTION: In this device, a movable reflection plate 5 can be disposed between a cold cathode tube as a light source 4 disposed in adjacent to a light guiding body 1 and a reflection plate 3 which surrounds the light source 4 with the side face of the light guiding body l. When the movable reflection plate 5 is not disposed between the light source 4 and the reflection plate 3, the plate 5 can be housed in a reflection plate housing 3a. Therefore, two kinds of illumination states can be obtd., namely, the light emitted from the light source 4 is reflected by the movable reflection plate 5 to the direction to the light transmission body 1 or the light is reflected by the reflection plate 3. Thus, chromaticity of the illumination face of the light guiding body 1 can be controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device which can easily adjust the chromaticity (white chromaticity) of illumination used in a display device such as a liquid crystal display device without changing a light source.

[0002]

2. Description of the Related Art FIG. 3 is a view showing an illumination device of a conventional liquid crystal display device.
FIG. 1 is a cross-sectional configuration diagram of a illuminating device of a sidelight type capable of correcting chromaticity disclosed in Japanese Unexamined Patent Publication (Kokai) No. H10-15095. In FIG.
Reference numeral 01 denotes a light guide plate, 102 denotes a reflector disposed on the side of the non-illuminated surface, 103 denotes a reflector of a light source, 104 denotes a light source such as a cold cathode tube, and 111 denotes a chromaticity correction filter layer.

The conventional illuminator of the sidelight type capable of correcting chromaticity configured as described above changes the white chromaticity of the illuminated surface by the chromaticity correction filter layer 111 without changing the chromaticity of the light source 104. I have.

However, in the above-described conventional illuminating device of the sidelight type capable of correcting the chromaticity, the chromaticity cannot be changed in real time while watching the illuminated surface. In addition, the chromaticity of the illuminated surface depends on the cold-cathode tube, which is the light source, and the chromaticity variation of the light source depends on the manufacturing variation of the cold-cathode tube. was there.

[0005]

As described above, it is difficult to change the chromaticity in real time and to adjust the chromaticity of the illuminated surface in the conventional illuminating device of the sidelight type capable of adjusting the chromaticity as described above. There was a problem. The present invention provides a liquid crystal display device including a lighting device capable of changing and adjusting the chromaticity of an illuminated surface in real time.

[0006]

According to the present invention, there is provided a liquid crystal display device comprising: a light guide; a first reflector disposed on a side of the light guide opposite to the illumination surface; Cold cathode tube, the second reflector surrounding the outer periphery of the cold cathode tube with the side surface of the light guide, it is possible to arrange between the second reflector and the cold cathode tube The movable reflector is moved so that the light emitted from the cold-cathode tube is reflected by the second reflector and the movable reflector is reflected by the movable reflector. Any of the states can be selected and used.

Further, in the liquid crystal display device according to the present invention, in addition to the above configuration, the movable reflection plate may be formed by a second reflection plate extending outside the first reflection plate and the first reflection plate. The structure is such that it can be stored in a reflection plate storage section formed by a gap.

Further, the liquid crystal display device according to the present invention comprises:
The light guide, the first reflector disposed on the side of the light guide opposite to the illuminating surface, the cold cathode tube disposed adjacent to the side of the light guide, and the side of the light guide, A second reflector surrounding the outer periphery of the cathode tube, comprising a filter covering a side surface of the light guide,
The filter can electrically control the transmittance and the transmission wavelength of light emitted from the cold cathode tube toward the light guide, and the light guide from the cold cathode tube is performed by electrical control of the filter. It can change the state of light applied to the body.

Further, the liquid crystal display device according to the present invention comprises a light guide, a reflection plate disposed on the non-irradiation surface side of the light guide, and a cold-cathode tube disposed adjacent to a side surface of the light guide. With
The reflection plate has a multilayer structure including a first reflection layer and a second reflection layer, and the first and second reflection layers each have different diffusion regions alternately arranged at a predetermined pitch. Any one or both of the first and second reflective layers can be slid, and by changing the overlapping state of the first and second reflective layers, diffuse reflection is performed on the reflective plate. It changes the state of light that is emitted.

Further, the liquid crystal display device according to the present invention comprises:
The first reflection layer has a structure in which first and second diffusion regions are alternately arranged at a predetermined pitch, and the second reflection layer has third and fourth diffusion regions alternately arranged at a predetermined pitch. The first, the third diffusion region, the third diffusion region, and the second diffusion layer by sliding one or both of the first and second reflection layers, That the diffusion region and the fourth diffusion region overlap each other, or the first diffusion region and the fourth diffusion region, and the second diffusion region and the third diffusion region Are superimposed on each other,
The overlapping state of the first and second reflecting layers is changed to change the state of light that is diffusely reflected on the reflecting plate having the multilayer structure.

Further, according to the liquid crystal display device according to the present invention, in the above configuration, the first and second reflection layers may include:
In the reflection layer disposed closest to the light guide, one diffusion region is constituted by a hole, and in a region corresponding to the hole, the diffusion region of the other reflection layer in a state overlapping the hole is formed. Diffuse reflection of light affects chromaticity.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Embodiment 1 of the present invention will be described. FIG. 1A is a cross-sectional configuration diagram of a lighting device of a liquid crystal display device according to the present invention. In this figure, reference numeral 1 denotes a light guide, 2 denotes a reflection plate located on a diffuse reflection surface on the side of the light guide 1 opposite to the illumination surface, and 3 denotes a light source such as a cold-cathode tube arranged adjacent to the light guide 1. A reflector 5 located on the specular reflection surface surrounding the reflector 4 and a movable reflector 5 which can be disposed in a gap between the reflector 3 and the light source 4 disposed on the specular reflection surface side, respectively.

The movable reflection plate 5 is a reflection plate 3 on the mirror reflection surface side extending outside the end of the reflection plate 2 located on the diffuse reflection surface.
And the reflection plate 2 can be stored in the reflection plate storage portion 3a formed by the gap between the reflection plate 2 and the outside of the end portion. FIG.
(B) shows a sectional configuration diagram when the movable reflection plate 5 is stored in the reflection plate storage portion 3a.

The movable reflecting plate 5 may be a diffuse reflecting plate, a specular reflecting plate, a chromaticity correcting filter (coloring filter, etc.), a wavelength selecting filter, as long as the chromaticity of the illuminating surface of the light guide 1 can be changed. Etc. may be appropriately selected. Movable reflector 5
1A and 1B, the reflection state of the light emitted from the light source 4 changes, and as a result, the chromaticity of the illumination surface changes. This allows
The state of the light can be changed before the light enters the light guide 1 without changing the chromaticity of the light source 4 itself, and the chromaticity of the illuminated surface can be adjusted.

Embodiment 2 Embodiment 1 already described
Then, the case where the reflected light is changed is mainly shown. In the second embodiment, a filter or the like is used in place of the movable reflection plate 5, and the filter is disposed so as to cover the end surface of the light guide 1, thereby changing transmitted light and adjusting the chromaticity of the illumination surface. It shows about that. When a filter is arranged on the side surface of the light guide 1, that is, between the light source 4 and the light guide 1, a filter capable of electrically controlling light transmittance and transmission wavelength is used. By using such an electrically controllable filter, the filter itself does not need to be movable, but can be fixed and used.

Even if a filter whose light characteristics cannot be controlled electrically is used in place of the above-described filter, as shown in the first embodiment, the storage portion corresponding to the reflection plate storage portion 3a is used. When it is desired to change the chromaticity of the illuminating surface without changing the chromaticity of the light source 4, the lower part of the light guide 1 is stored between the light source 4 and the light guide 1. It is possible to change the chromaticity of the illuminated surface in real time by moving and disposing the filter from the unit.

Embodiment 3 Next, a third embodiment of the present invention will be described with reference to FIG. In the first embodiment, an example in which the movable reflection plate 5 is additionally formed in the illumination device portion of the liquid crystal display device has been described. In the third embodiment, the movable reflection plate 5 is not formed in the illumination device portion. The chromaticity of the illuminating surface is changed by deforming the reflecting plate 2 disposed on the side opposite to the illuminating surface of the light guide 1 and using the reflecting plate 2a composed of at least two layers having a function as a reflecting plate. Here is an example.

In FIG. 2, reference numeral 6 denotes a diffusion area 6a.
And a hole 6b are a first reflective layer alternately formed at a predetermined pitch, and the first reflective layer 6 is mounted closest to the light guide 1. Reference numeral 7 denotes a second reflective layer disposed so as to overlap the outside of the first reflective layer 6, and the second reflective layer 7 includes a first diffusion region 7a and a second diffusion region 7b. Are alternately arranged and formed so as to have the same pitch as in the case of the first reflective layer 6. Further, the second reflection layer 7 has a structure that can be slid. In addition, the same reference numerals as those already used for the description indicate the same or corresponding parts.

The first reflective layer 6 and the second reflective layer 7 can be appropriately selected and used as long as the chromaticity of the light source 4 can be changed, such as a diffuse reflector or a specular reflector. Further, as shown in FIG. 2, when the first reflection layer 6 and the second reflection layer 7 are in a positional relationship such that the diffusion region 6a and the second diffusion region 7b respectively overlap, Second reflective layer 7
The light diffusely reflected at the first diffusion region 7a and the diffusion region 6a of the first reflection layer 6 is incident on the light guide 1 side.

The second reflection layer 7 is slid by one pitch so that the hole 6b of the first reflection layer 6 and the second diffusion region 7b of the second reflection layer 7 overlap. Accordingly, the diffuse reflection surface in the area occupied by the hole 6b can be changed, and the state of light applied to the illumination surface side of the light guide 1 can be changed with this change. It is possible to change the chromaticity of the illuminated surface without changing the chromaticity of the light source 1. In addition, although the example in which the hole 6b is formed in the first reflective layer 6 has been described, the present invention is not limited to this, and the first reflective layer 6 may be formed of a film having an arbitrary transmittance.

In the above example, the case where the second reflection layer 7 disposed on the side farther from the light guide 1 of the reflection plate 2a is movable is described. However, the present invention is not limited to this. It is also possible to adopt a method in which the first reflection layer 6 arranged on the side close to 1 is movable and the second reflection layer 7 is fixed, and as another example, the first and second reflection layers are provided. A method in which both the layers 6 and 7 are movable, and the chromaticity of the backlight is adjusted by sliding in opposite directions by a half pitch corresponding to half the width of the formed diffusion region. Needless to say, this is also possible.

[0022]

The effects of the present invention will be described below. According to the present invention, a structure in which a movable reflection plate can be arranged between a cold cathode tube and a reflection plate surrounding the cold cathode tube is provided, and by moving the movable reflection plate, the cold cathode tube itself as a light source is moved. A liquid crystal display device capable of adjusting the chromaticity of the illuminated surface of the light guide without changing the chromaticity can be obtained.

According to the invention, a filter capable of electrically controlling light transmittance and transmission wavelength is disposed between the cold-cathode tube and the light guide, so that the cold-cathode tube as a light source is provided. A liquid crystal display device capable of adjusting the chromaticity of the illuminated surface without changing the chromaticity of itself and without changing the arrangement of the filter itself can be obtained.

Further, according to the present invention, the reflecting plate disposed on the reflection surface side of the light guide has a two-layer structure, and by changing the overlapping state of the two reflecting layers,
It is possible to obtain a liquid crystal display device capable of adjusting the chromaticity of the illuminated surface without changing the chromaticity of the cold-cathode tube itself, which is the light source, by changing the state of light under the influence of the reflector.

[Brief description of the drawings]

FIG. 1 is a sectional configuration diagram of a lighting device according to a first embodiment of the present invention.

FIG. 2 is a sectional configuration diagram of a lighting device according to a third embodiment of the present invention.

FIG. 3 is a cross-sectional configuration diagram of a lighting device according to a conventional technique.

[Explanation of symbols]

1 light guide, 2, 2a, 3 reflector,
3a reflector storage section 4 light source, 5 movable reflector,
6 first reflection layer 6a diffusion region, 6b hole,
7 Second reflective layer 7a First diffusion region, 7b Second diffusion region.

Claims (6)

[Claims] 1. A light guide, a first reflector disposed on a side of the light guide opposite to an illuminated surface, a cold-cathode tube disposed adjacent to a side surface of the light guide, A liquid crystal, comprising: a second reflector surrounding a periphery of the cold-cathode tube with a side surface; and a movable reflector that can be arranged between the second reflector and the cold-cathode tube. Display device. 2. The movable reflector can be housed in a reflector housing portion formed by a gap between the second reflector extending outside the first reflector and the first reflector. The liquid crystal display device according to claim 1, wherein 3. A light guide, a first reflector disposed on a side of the light guide opposite to the illumination surface, a cold-cathode tube disposed adjacent to a side surface of the light guide, and a light guide of the light guide. A second reflector surrounding the outer periphery of the cold cathode tube with a side surface, a filter covering the side surface of the light guide, the filter is configured to emit light emitted from the cold cathode tube toward the light guide. A liquid crystal display device wherein transmittance and transmission wavelength can be electrically controlled. 4. A light guide, a reflector disposed on a side opposite to the irradiation surface of the light guide, and a cold-cathode tube disposed adjacent to a side surface of the light guide. A multilayer structure including one reflective layer and a second reflective layer, the first and second reflective layers each have a different diffusion region alternately arranged at a predetermined pitch, the first, the second A liquid crystal display device wherein one or both of the two reflective layers can be slid. 5. The first reflection layer has a structure in which first and second diffusion regions are alternately arranged at a predetermined pitch, and the second reflection layer has a third and fourth diffusion regions. It is a structure arranged alternately at a predetermined pitch, by sliding one or both of the first and second reflective layers, the first diffusion region and the third diffusion region ,
And the second diffusion region and the fourth diffusion region overlap each other, or, the first diffusion region and the fourth diffusion region, and the second diffusion region and the fourth diffusion region The liquid crystal display device according to claim 4, wherein the three diffusion regions overlap each other. 6. The reflection layer disposed closest to the light guide among the first and second reflection layers, wherein one diffusion region is constituted by a hole. Or the liquid crystal display device according to claim 5.