JP3529906B2 - Liquid crystal display - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention holds a light-scattering liquid crystal layer between two substrates provided with liquid crystal driving electrodes, and provides a light reflecting element behind the liquid crystal layer as seen from an observer, The present invention relates to a liquid crystal display device that performs display by controlling the light scattering property of a liquid crystal layer by a voltage applied to electrodes.

[0002]

2. Description of the Related Art In a conventional reflective liquid crystal display element such as TN or STN which requires a polarizing plate, a dark display is produced when light from a direction close to regular reflection is blocked due to the characteristics of the reflective polarizing plate. However, in the light-scattering type liquid crystal element, light from a direction largely deviated from the specular reflection direction can be effectively used, so that bright display is possible. However, there are the following problems. To explain this problem with reference to FIG. 1, in the display device using the light-scattering liquid crystal element 2 and the light-reflecting element 1, when the light-scattering liquid crystal element 2 is in the light-scattering state like 2a and 2c, The light scattered forward by the liquid crystal element is returned to the liquid crystal element by the light reflecting element, and is forward scattered again, and a part of the light proceeds to the direction of the observer 3 to obtain a bright background. preferable. However, in the case of a transparent state like 2b, the incident light 5 from the specular reflection direction when looking at the reflective element from the observation direction directly enters the observer, and when there is a bright object in the direction of 5, A bright display is displayed on a bright background, and sufficient contrast cannot be obtained. As a method of improving this problem, there are a method of blocking the specular reflection light 4 from the light reflecting element and a method of blocking the incident light 5 in the specular reflection direction. Japanese Patent Laid-Open No. 4-2
No. 12125 is characterized in that a selective transmission layer for transmitting light in a predetermined range corresponding to the observation direction and reflecting the other light to the liquid crystal display element side is arranged on the back surface of the light scattering liquid crystal element. Although a liquid crystal display element is described, this liquid crystal display element also has problems such as high cost and insufficient reflection intensity.

[0003]

The object of the present invention is to provide a reflective light-scattering liquid crystal device using a mirror as a light-reflecting device, when the liquid crystal layer has a low light-scattering property, for example, when the liquid crystal layer is in a transparent state. An object of the present invention is to provide a liquid crystal display device having excellent display quality by solving the problem of the above-described conventional technique that the display performance is inferior because the specular reflection image is visually recognized.

[0004]

[Structure] The present invention relates to two substrates provided with liquid crystal driving electrodes.
Hold a light-scattering liquid crystal layer between them, and
A light reflecting element is provided behind the crystal layer and applied to the electrode.
The voltage is controlled by controlling the magnitude of the light scattering property of the liquid crystal layer.
In the liquid crystal display device that shows the
In between, light that can limit the light that travels in the direction of the observer
A state in which the control means is provided and the light control means is deviated into a plurality of layers
And a liquid crystal display device characterized by being a light-shielding layer arranged in parallel with the liquid crystal layer . As the liquid crystal driving electrode, substrate and liquid crystal layer used in the liquid crystal display device of the present invention, those conventionally used in liquid crystal display devices are used.
For example, as the light-scattering liquid crystal layer, polymer dispersed liquid crystal,
A liquid crystal such as a phase transition type liquid crystal or a transient scattering type liquid crystal is used. Further, as the substrate, a glass substrate or a polymer substrate such as polycarbonate, polyethylene terephthalate, polyether sulfone, or polyacrylate,
Further, an oxide such as indium and tin is used as the liquid crystal driving electrode.

The structure and operation of the liquid crystal display device of the present invention will be specifically described below based on the following embodiments. However, the liquid crystal display device of the present invention is not limited to the following examples.

[0006]

【Example】Reference example 1 In Figure 2Reference exampleThe cross-sectional view of the structural example of FIG. Light-scattering liquid crystal element
The light control means 6 is arranged between the child 2 and the light reflection element 1.
There is. The light control element 6 is one of the light reflected from the light reflection element 1.
However, it absorbs all or part of the components that go in the observation direction 3.
It has to be something like In Figure 3, such
A cross-sectional view when the louver 7 is used as the light control means is shown.
You Layered light-shielding layer 8 is arranged on the louver 7 as shown in the figure.
Centered on the light traveling in the direction normal to the light-shielding layer 8.
In order to absorb, the reflected light does not travel in this direction,
From this, the color of the viewer-side surface of the light shielding layer 8 is visually recognized. Light scattering
When the disturbing liquid crystal element 2 is in the light-scattering state, it may be between the light-shielding layers 8.
The light incident on the liquid crystal layer is scattered and is visually recognized.
It is possible to obtain sufficient brightness. Liquid crystal element scatters light
In order to further improve the brightness when
The back surface of the layer 8 (surface on the side of the reflection layer) is a reflection plate having a high reflectance, or
It is desirable that it is a diffuse reflector. Light control as above
The control element is, for example, as shown in FIG.
And a light reflection layer are repeatedly laminated to cut out a laminated plate.
It can be manufactured by In Figure 2, the display surface
Stands almost vertically, like an observer looking down at the display
Although the positional relationship is shown, depending on the application, the display device
Sometimes you can look up at the
There is also a case to use. Light controllability of the louver
The angle of the light-shielding layer 8 varies greatly depending on the angle of 8
Optimum degree depending on application or observer's observation position
Is desirable. Look up the display element from below
For various applications, the orientation of the louver should be as shown in Fig. 4.
Yes. Like the blinds, the angle of the light shielding layer 8 can be freely changed.
If the configuration is such that
It can be adjusted, which is very preferable. Note that the figure
2, the light reflection element 1 and the light-scattering liquid crystal element 2 have different configurations.
However, for example, the light-reflecting element 1 is used as a light-scattering liquid crystal element.
The electrodes of the light-scattering liquid crystal element 2 which are formed inside the child 2
By using a structure that doubles as a reflective element, light reflection
The element 1 and the light-scattering liquid crystal element 2 can be integrally formed.
Noh.

Example1 Reference example 1 In the liquid crystal display device of FIG.
A display device having a cross-sectional structure as shown in FIG.
It was With this configuration, the light-shielding layers 10 arranged in two rows are displaced from each other.
However, when viewed from the viewing direction 3, the light-scattering liquid crystal overlaps.
When the surface of the light shielding layer is visible when the element 2 is transparent,
And display becomes possible. As a light control meansReference example 1To
With a louver as shown, the normal direction of the display
It is difficult to see from the
This is possible with control means. Again, the light
Increases the brightness when the scattering liquid crystal element 2 is light scattering.
In order to reduce the thickness, the back surface of the light shielding layer 10 has a high reflectance.
Is preferred. In addition, the light-shielding layers arranged so as to be offset in the two rows
Does not necessarily have to be two rows, but three or more rows
May be The light control means 9 in FIG.
Disassemble into parts as shown in 9a and 9b, and watch 9a and 9b.
A member structure that can be shifted according to the direction of observation
This makes it possible to adjust the viewing angle with a simple configuration.
Yes.

[0008]Reference example 2 For the liquid crystal element 2b in the transparent state, the observation direction 3
The part 14 which is the direction of specular reflection when viewed from above is reflected
However, the light control element 13 that does not reflect light in the direction of 5
This can be prevented by arranging them. Figure 8
As an example of a light control means having such a function,
Shows a bar 13. Like a specular reflection toward the observer
The light 5 ′ traveling in the direction is absorbed by the light shielding layer 8 ′.
The light 12 traveling in the other direction is the louver 1
Through 3. Instead of the light control means 13, a light reflection is generated.
It is possible to display even if a light absorber that does not rub is placed.
However, in that case, it is impossible to see under the light absorber.
Is. If the light control means such as the light control means 13,
It is possible to see below the light control means, and
Display or operate keyboard, operation panel, etc.
It is possible to arrange the panel 15. This is shown in Figure 9.
The example of FIG. As a light control means, a rule as shown in FIG.
In addition to the bar 13,Reference Example 1 and Example 1Also illustrated in
Can be used as well.

[0009]Reference example 3 In the configuration example of FIG. 7, touch the upper surface of the light control unit 13.
Overlay the panel 16 andLight control meansBelow 13 is another
The display element 17 was arranged and used as an operation plate (FIG. 10). this
With the configuration, the light-scattering liquid crystal element 2 is very bright and
Not only good acceptance but also light control means 13 and touch panel
16 and display element 17 provide more functions
It is possible to give.

[0010]Reference example 4 In Figure 11Reference example 4Shows a cross-sectional view of the configuration example of the liquid crystal display device of
You Arranging the light-shielding means 6a in the direction of specular reflection viewed from the observer 3.
did. At least the surface of the light shielding means 6a should be black.
Is desirable, but by coloring it, the light-scattering display element
The display of the child 2 is colored on a white background. Shading means
If the surface of 6a is matte black, it will be
A large display of trust is possible. Use this display device
When not in use, the light-shielding means 6a is placed on the light-scattering display element 2.
It is also possible to configure it as a means for protecting the display section.
It In the configuration of FIG. 11, the light shielding means 6a and the light reflecting element 1 are
The angle formed by the light-scattering display element 2 should be approximately 90 degrees.
However, it is preferable to attach an angle adjustment mechanism.
Good

[0011]Reference example 5 Reference example 5 FIG. 12 shows a configuration example of the liquid crystal display device. this
In the example, the liquid crystal parts are 2a, 2b and 2c and the light reflection element 1
The display part is almost horizontal and supports this.
Then, the light-shielding means is vertically formed. Also in this case
The light means 7a, the light reflection element 1, and the light scattering display element 2 form
Depending on the lighting conditions, a mechanism that can adjust the angle can be used.
It is possible and preferable.

[0012]Reference example 6 In FIG. 13, the liquid crystal display device shown in FIG.
The structure which overlapped the operation panel 15 is shown. Operation in this configuration
The panel 15 needs to be at least partially transparent.
It

[0013]Reference example 7 FIG. 14 shows a structure in which the operation panel 15 is arranged other than the display unit.
Indicates success. In this case the operation panel need not be transparent
No, you can use general input means such as a keyboard
Becomes

[0014]Reference example 8 FIG. 15 shows an example of the color filter. Color filter
-18 is provided on the side opposite to the reflective element 1. T
In the conventional mode such as N and STN, the color filter 18
The position of does not differ in principle on either side of the liquid crystal layer.
Backscattering in liquid crystal element 2 in light scattering mode
Since the light is also visible, the color filter 18 is a liquid crystal layer.
Is preferably placed between the observer and the observer. In addition,
In the display, the display light passes through the color filter twice.
In addition, the optical density is about half that of the conventional one. Good
More preferably, the conventional 70% to 30% is preferable. Same as before
If the optical density of the
Yes. The characteristic of the transmission spectrum is that the visible light transmission
Wavelength or 650 nm transmittance is 85% or less
Above all, it is preferably 90% or more. Conventional and
Similarly, a black matrix may be provided between pixels.
Yes.

[0015]

[Effect] Light does not travel in the normal direction of the light shielding layer, and
A liquid crystal display device was obtained in which the color of the surface on the observer side was visually recognized .

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration of a conventional light-scattering type liquid crystal display element.

FIG. 2 is a diagram schematically showing a configuration of a liquid crystal display element in which a light control unit is arranged between a liquid crystal element and a reflective element of a light scattering type liquid crystal display device of Reference Example 1 .

FIG. 3 is a diagram schematically showing a configuration of a liquid crystal display element having a louver in which a light shielding layer is arranged, in the liquid crystal display element of FIG.

4 is a diagram schematically showing a configuration of a liquid crystal display element in which the orientation of a louver is changed in the liquid crystal display element of FIG.

FIG. 5 is a schematic diagram showing the configuration of the liquid crystal display element of Example 1 in which a plurality of rows of light-shielding layers are arranged parallel to each other in the liquid crystal display element of FIG. FIG.

6 is a diagram schematically showing a configuration of a liquid crystal display element of the liquid crystal display element of FIG. 5, in which a plurality of columns of light-shielding layers can be disassembled for each column.

7 is a diagram schematically showing the configuration of a light-scattering liquid crystal display device of Reference Example 2. FIG.

8 is a diagram schematically showing a configuration of a louver used in the light scattering type liquid crystal display device of FIG.

9 is a light control unit 13 of the light-scattering type liquid crystal display device of FIG.
It is a figure which shows typically the structure of the liquid crystal display device which provided the operation panel below.

10 is a diagram schematically showing a configuration of a liquid crystal display device in which a touch panel is provided on the upper surface and a display element is provided on the lower surface of a light control unit of the light scattering type liquid crystal display device of FIG.

FIG. 11 is a diagram schematically showing a configuration of a light-scattering type liquid crystal display device of Reference Example 4 .

12 is a diagram schematically showing the configuration of the liquid crystal display device of the liquid crystal display device of FIG. 11, in which the display unit is arranged substantially horizontally and the light shielding means is arranged substantially vertically.

13 is a diagram schematically showing a liquid crystal display device having a configuration in which an operation panel 15 is overlaid on the display section of the liquid crystal display device shown in FIG.

14 is a diagram schematically showing a liquid crystal display device shown in FIG. 13, which has a configuration in which an operation panel 15 is arranged other than a display section.

FIG. 15 is a diagram schematically showing a liquid crystal display unit in which a color filter layer is arranged on the viewer side of the liquid crystal layer.

FIG. 16 is a diagram showing an example of a method of manufacturing a light control element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Light-reflecting element (mirror) 2 Light-scattering liquid crystal element 2a Light-scattering liquid crystal element 2c Light-scattering liquid crystal element 2b Transparent liquid crystal element 3 Viewer direction 4 Specular reflection light 4'to viewer direction 4 ' Specularly reflected light 5 Directionally directed light 5'Directive light directed to the observer 5'Light directionally directed to viewer's direction 6 Light control means (light-shielding means) 6a Light-shielding means or display Protecting means and shading means 7 Light control means (louver) 7a Shielding means or shading means or shading means 8 Shading layer 8'Light blocking layer 9 Light control element 9a Light control element 9b Light control element 10 Light blocking layer 11 Illumination Light 12 Diffuse reflected light 12a in a direction other than the direction that causes specular reflection toward the viewer 12a Part of diffuse reflected light 12b 12 Part of diffuse reflected light 12 Light control means (louver) 14 Reflected portion 15 operations Panel 16 Touch panel 17 Display element 18 Color filter 18B Color filter Blue 18G Color filter Green 18R Color filter Red 19 Transparent layer 20 Light shielding layer 21 Light reflection layer

Continuation of front page (56) Reference JP-A-5-45631 (JP, A) JP-A-3-226718 (JP, A) JP-A-6-75218 (JP, A) JP-A-6-317702 (JP , A) JP-A-6-75218 (JP, A) JP-A-54-105998 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02F 1/1335 G02F 1/1335 500 G02F 1/1335 520

Claims (4)

(57) [Claims] 1. A light-scattering liquid crystal layer is sandwiched between two substrates provided with liquid crystal driving electrodes, and a light reflecting element is provided behind the liquid crystal layer when viewed from an observer, and applied to the electrodes. In a liquid crystal display device that controls display by controlling the magnitude of light scattering of the liquid crystal layer by the applied voltage, a light control device that can limit the light traveling toward the viewer between the light reflecting element and the liquid crystal layer.
Control means is provided, and the light control means is deviated into a plurality of layers,
A liquid crystal display device characterized by being a light-shielding layer arranged in parallel with the liquid crystal layer . 2. The liquid crystal display device according to claim 1,
A plurality of rows of light-shielding layers are parallel to each other facing the observer direction, and
A liquid crystal display device that is arranged so as to be offset for each row . 3. The liquid crystal display device according to claim 1 or 2.
Where the light control means is a liquid whose viewing angle can be adjusted.
Crystal display device. 4. The liquid crystal display device according to claim 1, wherein the back surface side (opposite layer side) of the light shielding layer has a high reflectance.
A liquid crystal display device.