JP3085291B2 - Reflective liquid crystal display device and reflective liquid crystal display method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type liquid crystal display device using a color filter and a reflection type liquid crystal display method.

[0002]

2. Description of the Related Art Generally, in a reflection type liquid crystal display device using a color filter and a reflection type liquid crystal display method, in order to enable liquid crystal display, incident light from outside the reflection type liquid crystal display device is reflected by a reflection electrode. , Need to pass through the liquid crystal.

The configuration and operation of a conventional reflection type liquid crystal display device are described in Journal of the Institute of Image Information and Television Engineers, Vol. 51, No. 7,1
This will be described with reference to FIG. A thin film transistor 33 is disposed on a glass substrate 31, and a reflection electrode 35 is disposed in a pixel region via an organic insulating film 34. The reflection electrode 35 and the thin film transistor 33 are electrically connected. The phase difference plate 3 is placed on a glass substrate 32 facing the glass substrate 31 with the nematic liquid crystal 41 interposed therebetween.
6, a polarizing plate 37 and a scattering plate 38 are arranged, and a color filter 39 and a common electrode 40 are formed on the opposite side of the glass plate 32 and the polarizing plate 37. A nematic liquid crystal 41 exists between the glass substrates 31 and 32. Scattering plate 38
Are disposed on the observer side of the glass substrate 32, and the mirror-surface reflective electrode 35 is disposed on the opposite side of the observer side of the glass substrate 32.
Since the distance between the scattering plate 38 and the reflective electrode 35 is greater than the thickness of one glass substrate 32, the observer can observe the incident light from outside by the reflective electrode 35 after being scattered by the outermost scattering plate 38. The reflected light reflected and the reflective electrode 35
In order to simultaneously observe the reflected light scattered by the scattering plate 38 after being specularly reflected in the display, a shaded display is viewed. Further, there is a problem that the display is blurred because multiple scattering and multiple reflection are repeated between the scattering plate 38 and the reflective electrode 35. Further, when the color filter 39 and the scattering plate 38 as a light scattering layer are separately provided, the number of steps for manufacturing the reflection type liquid crystal display device increases, and the film becomes a multi-layer film and the thickness through which light is transmitted increases, so that light absorption is reduced. There is a disadvantage that the reflection screen is darkened.

[0004]

SUMMARY OF THE INVENTION In order to solve these problems, the present invention makes it possible to eliminate the occurrence of display shadows, display blur, and display darkness, and to make the display clear. It is an object of the present invention to provide a reflection type liquid crystal display device and a reflection type liquid crystal display method capable of reducing the manufacturing cost by reducing the number of manufacturing steps.

[0005]

According to a first aspect of the present invention, there is provided a reflective liquid crystal display device, wherein the diameter of fine particles of a pigment constituting a color filter layer is equal to the length of a visible light wavelength region. There is a feature.

Therefore, according to the reflection type liquid crystal display device of the first invention of the present application, since the diameter of the fine particles of the pigment constituting the color filter layer is the length of the wavelength region of visible light, visible light is reduced. Visible light can be scattered moderately without being easily scattered and, on the contrary, being too scattered to darken the display. Further, since the diameter of the pigment fine particles constituting the color filter layer is the length of the wavelength region of visible light, the color filter layer can also serve as a light scattering function, and the thickness of the layer through which light passes can be reduced. Can be
The display can be brightened. Further, since the diameter of the pigment fine particles constituting the color filter layer is the length of the wavelength region of visible light, the color filter layer can also serve as a light scattering function, thereby reducing the manufacturing process and the manufacturing cost. become.

The reflection type liquid crystal display device of the second invention of the present application is characterized in that the diameter of the pigment fine particles constituting the color filter layer is 0.4 μm or more and 0.7 μm or less.

Therefore, according to the reflection type liquid crystal display device of the second invention of the present application, since the diameter of the fine particles of the pigment constituting the color filter layer is 0.4 μm or more and 0.7 μm or less, the wavelength becomes zero. Light having a wavelength of 0.4 μm or more and 0.7 μm or less is not easily scattered, and the display is not darkened.
m or less can be appropriately scattered. Further, when the diameter of the pigment fine particles constituting the color filter layer is 0.4 μm or more and 0.7 μm or less,
The color filter layer can also serve as a light scattering function, and further, the thickness of the layer through which light passes can be reduced, and the display can be made bright. Further, the diameter of the pigment fine particles constituting the color filter layer is 0.4 μm or more and 0.7 μm or less.
When the number m is not more than m, the color filter layer can also serve as a light scattering function, and the number of manufacturing steps and manufacturing costs can be reduced.

The reflection type liquid crystal display device according to the third invention of the present application is characterized in that it has a color filter layer containing pigment fine particles that scatter visible light in multiple directions.

Therefore, according to the reflection type liquid crystal display device of the third invention of the present application, the visible light is easily scattered by having the color filter layer containing the pigment fine particles that scatter the visible light in multiple directions. On the other hand, the display is not darkened due to excessive scattering, and the visible light can be scattered appropriately. In addition, by having a color filter layer containing pigment fine particles that scatter visible light in multiple directions, the color filter layer can also serve as a light scattering function, and the thickness of a layer through which light passes can be further reduced. , The display can be brightened. Furthermore, by having a color filter layer containing pigment fine particles that scatter visible light in multiple directions, the color filter layer can also serve as a light scattering function, and the manufacturing process and manufacturing cost can be reduced.

According to a fourth aspect of the present invention, in the reflective liquid crystal display device according to any one of the first to third aspects of the present invention, the reflective electrode and the color filter layer are close to each other. Features.

Therefore, according to the reflection type liquid crystal display device of the fourth invention of the present application, since the reflection electrode and the color filter layer come close to each other, the occurrence of display shadow and display blur due to parallax is eliminated. It becomes possible.

According to a fifth aspect of the present invention, in the reflective liquid crystal display device according to any one of the first to third aspects of the present invention, a reflective electrode is in contact with the color filter layer. I do.

Therefore, according to the reflection type liquid crystal display device of the fifth invention of the present application, since the reflection electrode and the color filter layer are in contact with each other, the reflection electrode and the color filter layer are closer to each other. Furthermore, it is possible to more completely eliminate the occurrence of display shadows and display blur due to parallax.

According to a sixth aspect of the present invention, there is provided a reflective liquid crystal display device according to any one of the first to fifth aspects of the present invention, wherein a reflective electrode and a pixel electrode are provided in a contact hole provided in a color filter layer. Characterized by being electrically conducted through

Therefore, according to the reflection type liquid crystal display device of the sixth invention of the present application, the reflection electrode and the pixel electrode are electrically connected to each other through the contact hole provided in the color filter layer. Since the electrode and the liquid crystal can be in direct contact, the drop of the applied voltage is small, the voltage use efficiency is improved, and the display can be sharpened. Further, since the reflective electrode and the pixel electrode are electrically connected to each other through the contact hole provided in the color filter layer, the pixel electrode can be extended over the transistor element and the drain, so that the pixel aperture ratio is reduced. Get higher,
The display can be sharpened.

The reflective liquid crystal display method according to the seventh aspect of the present invention is characterized in that reflected light is displayed by passing visible light through a color filter that scatters light in multiple directions.

Therefore, according to the reflective liquid crystal display method of the seventh aspect of the present invention, the visible light is scattered by displaying the reflected light by passing the visible light through a color filter which scatters the light in multiple directions. Visible light can be scattered appropriately without being easily scattered and the display being darkened by too much scattering. Also, by displaying the reflected light by passing the visible light through a color filter that scatters light in multiple directions, the color filter layer can also serve as a light scattering function, and further reduce the thickness of the layer through which light passes. And the display can be brightened. Further, by displaying the reflected light by passing the visible light through a color filter that scatters light in multiple directions, the color filter layer can also serve as a light scattering function, and the manufacturing process and manufacturing cost can be reduced. .

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a reflection type liquid crystal display device and a reflection type liquid crystal display method of the present invention are shown in FIGS.
A description will be given based on FIG.

Embodiment FIG. 1 is a sectional view of a reflection type liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is a plan view of the reflection type liquid crystal display device of one embodiment of the present invention. is there. The configuration of the reflective liquid crystal display device according to the embodiment of the present invention will be described in detail with reference to FIGS. A gate electrode 3 is provided on a part of the substrate 1, a gate insulating film 4 is provided on the substrate 1 and the gate electrode 3, and a semiconductor layer 5 and a drain The electrode 6, the reflective electrode 7, and the color filter layers 8R, 8G, 8B are provided;
A contact hole 9 is provided in a part on the reflective electrode 7, a pixel electrode 10 is provided on a part on the color filter layers 8R, 8G, 8B and on the contact holes 9, and a contact hole 9 is provided on the color filter layers 8R, 8G, 8B. An alignment film 12 is provided on a part of the pixel electrode 10, a nematic liquid crystal 16 layer is provided on the alignment film 12, an alignment film 13 is provided again on the nematic liquid crystal 16 layer, and a transparent electrode 11 is provided on the alignment film 13. The substrate 2 is provided again on the transparent electrode 11, a phase plate 14 is provided on the substrate 2, and a polarizing plate 15 is provided on the phase plate 14. In the configuration of the reflection type liquid crystal display device of the present invention described above, the color filter layer 8
The diameter of the fine particles of the pigment constituting R / 8G / 8B is the length of the wavelength region of visible light. In addition, the color filter layer 8
The diameter of the pigment fine particles constituting R.8G.8B is 0.
Color filter layer 8R having a size of 4 μm or more and 0.7 μm or less or containing pigment fine particles that scatter visible light in multiple directions.
It is possible to have 8G / 8B. Also,
The reflective electrode 7 and the color filter layers 8R, 8G, and 8B are close to each other. Specifically, the color filter layers 8R, 8G, and 8B are provided on the observer-side surface of the reflective electrode 7.
Further, the reflective electrode 7 and the pixel electrode 10 are electrically connected via a contact hole 9 provided in the color filter layer. Specifically, the color electrode provided on the observation side surface of the reflective electrode 7 is provided. A part of the pixel electrode 10 provided on the observer side surface of the color filter layers 8R, 8G, and 8B and the reflective electrode 7 are provided on a part of the filter layers 8R, 8G, and 8B.
Are provided. Next, the operation and method of the embodiment of the present invention will be described in detail with reference to FIGS. Light is incident from above the polarizing plate 15, the incident light is linearly deflected by the polarizing plate 15, and the incident light undergoes birefringence and rotation in the phase difference plate 14 and the nematic liquid crystal 16 layer, and then becomes red, green, and Each of the blue color filter layers 8R, 8G, and 8B is separated into each color and transmitted or scattered. Color filter layer 8R
The light transmitted through the 8G / 8B is specularly reflected by the reflective electrode 7, is again spectrally scattered and scattered by the color filter layers 8R / 8G / 8B, and is birefringent again by the nematic liquid crystal 16 and the retardation plate 14. Then, the light in the direction matching the transmission axis is transmitted through the polarizing plate 15. In the configuration of the reflection type liquid crystal display device of the present invention described above, the color filter layers 8R and 8G
The color filter layer 8R has a diameter of the fine particles of the pigment constituting the color filter 8B which is the length of the wavelength region of visible light.
G · 8B can also serve as a light scattering function, and the distance of the thickness of the layer through which light passes, that is, the distance between the reflective electrode 7 and the polarizing plate 15 can be shortened, and the display can be brightened. become. The color filter layers 8R, 8G, 8
Since the diameter of the pigment fine particles constituting B is the length of the wavelength region of visible light, the color filter layers 8R, 8G,
8B can also serve as a light scattering function, so that the number of manufacturing steps and manufacturing costs can be reduced. Further, the diameter of pigment fine particles constituting the color filter layers 8R, 8G, 8B is 0.4 μm or more and 0.7 μm or less, and the color filter layers 8R ・ 8G containing pigment fine particles that scatter visible light in multiple directions. By having 8G / 8B, it is possible to obtain exactly the same effect as in the case where the diameter of the pigment fine particles constituting the color filter layers 8R / 8G / 8B is the length of the wavelength region of visible light. In addition, since the reflective electrode 7 and the color filter layers 8R, 8G, and 8B come closer to each other, it is possible to eliminate the occurrence of display shadow and display blur due to parallax. Further, the reflection electrode 7 and the pixel electrode 10
Is electrically conducted through the contact holes 9 provided in the color filter layers 8R, 8G, and 8B, so that the pixel electrode 10 and the nematic liquid crystal 16 can be in direct contact with each other. The use efficiency is improved, and the display can be sharpened. Further, the reflection electrode 7 and the pixel electrode 10 are connected to the color filter layer 8R.
The pixel electrode 10 can be electrically spread over the semiconductor layer 5 and the drain electrode 6 by being electrically conducted through the contact holes 9 provided in the 8G and 8B, so that the pixel aperture ratio can be increased. And the display becomes clearer. Further, by providing a black matrix in the reflective liquid crystal display device of the present invention, display contrast is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a reflective liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a plan view of a reflective liquid crystal display device according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a conventional reflection type liquid crystal display device.

[Explanation of symbols]

 7 Reflective electrode 8R Red color filter layer 8G Green color filter layer 8B Blue color filter layer 9 Contact hole 10 Pixel electrode 14 Phase difference plate 15 Polarizer 16 Nematic liquid crystal

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02B 5/20 101 G02B 5/22 G02F 1/1335 505 G02F 1/1335 520

Claims (7)

(57) [Claims] 1. A reflection type liquid crystal display device, wherein a diameter of fine particles of a pigment constituting a color filter layer is a length of a visible light wavelength region. 2. A reflection type liquid crystal display device, wherein the fine particles of the pigment constituting the color filter layer have a diameter of 0.4 μm or more and 0.7 μm or less. 3. A reflective liquid crystal display device comprising a color filter layer containing pigment fine particles that scatter visible light in multiple directions. 4. The color filter layer according to claim 1, wherein the reflection electrode and the color filter layer are close to each other.
The reflective liquid crystal display device according to any one of the above. 5. The reflection type liquid crystal display device according to claim 1, wherein a reflection electrode and the color filter layer are in contact with each other. 6. The pixel according to claim 1, wherein the reflective electrode and the pixel electrode are electrically connected via a contact hole provided in the color filter layer. Reflective liquid crystal display. 7. A reflection type liquid crystal display method comprising displaying reflected light by passing visible light through a color filter which scatters light in multiple directions.