JPH10111502A - Reflective guest-host liquid crystal display - Google Patents

Abstract

(57) [Problem] To suppress luminance unevenness and color unevenness caused by a light reflecting layer of a reflection type guest host liquid crystal display device. SOLUTION: A guest-host liquid crystal layer 3 is held between a substrate 1 on an incident side and a substrate 2 on a reflection side. The light diffusion layer 25 is interposed between the substrate 1 and the guest host liquid crystal layer 3, while the light reflection layer 9 is interposed between the substrate 2 and the guest host liquid crystal layer 3. The guest host liquid crystal layer 3 and the light reflection layer 9
And a quarter-wave plate layer 10 is interposed therebetween. The electrodes 6 and 11 formed on the pair of upper and lower substrates 1 and 2 respectively apply a voltage to the guest host liquid crystal layer 3. As a characteristic feature, the light reflection layer 9 has a periodic structure and scatters and reflects the incident light that has entered from the substrate 1 side, while the light diffusion layer 25 diffusely reflects the reflected light that has returned from the light reflection layer 9. And is emitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a reflection type guest-host liquid crystal display device. More specifically, the present invention relates to a technique for improving the efficiency of using incident light by incorporating a quarter-wave plate layer and a light reflection layer in a panel. More specifically, the present invention relates to a technique for improving the reflection characteristics of a light reflection layer to improve the brightness and visibility of a display.

[0002]

2. Description of the Related Art A reflection type guest-host liquid crystal display device having a built-in quarter-wave plate layer and a light reflection layer is disclosed, for example, in Japanese Patent Laid-Open No.
FIG. 7 shows a cross-sectional structure thereof. This reflective guest-host liquid crystal display device 10
1 is a pair of upper and lower substrates 102 and 103, a guest-host liquid crystal layer 104, a dichroic dye 105, and a pair of upper and lower electrodes 10
6 and 110, a pair of upper and lower alignment films 107 and 111, a light reflection layer 108, and a quarter-wave plate layer 109. The pair of substrates 102 and 103 are made of an insulating material such as glass, quartz, and plastic. Also, at least the upper substrate 102 located on the incident side is transparent. In the gap between the pair of substrates 102 and 103, a guest-host liquid crystal layer 10 containing a dichroic dye 105
4 are held. The guest-host liquid crystal layer 104 contains nematic liquid crystal molecules 104a, and the dichroic dye 1
05 is a so-called p-type dye having a transition dipole moment substantially parallel to the long axis of the molecule. Although not shown, a switching element is integrally formed on the inner surface 102a of the upper substrate 102. The transparent electrode 106 is patterned in a matrix as a pixel electrode, and is driven by a corresponding switching element. Further, the upper substrate 10
2 is covered with an alignment film 107 made of polyimide resin or the like. The surface of the alignment film 107 is, for example, subjected to a rubbing treatment, so that the nematic liquid crystal molecules 104
a is horizontally oriented.

On the other hand, the lower substrate 103 located on the reflection side
On the inner surface 103a, a mirror-like light reflecting layer 108 made of aluminum or the like and a quarter-wave plate layer 109 made of a polymer liquid crystal or the like are formed in this order. Further, on the quarter-wave plate layer 109, a transparent counter electrode 110 and an alignment film 111 are formed in this order.

Next, the operation of the reflective guest-host liquid crystal display device 101 for monochrome display will be briefly described. When performing color display,
A color filter may be provided on one of the upper and lower substrates 102 and 103. When no voltage is applied, the nematic liquid crystal molecules 104a are horizontally oriented, and the dichroic dye 105 is similarly oriented. When light incident from the upper substrate 102 proceeds to the guest-host liquid crystal layer 104, a component of the incident light having a vibration plane parallel to the major axis direction of the molecules of the dichroic dye 105 is generated by the dichroic dye 105. Absorbed. The component of the dichroic dye 105 having a vibration plane perpendicular to the major axis direction of the molecule is the guest-host liquid crystal layer 10.
4, the light is circularly polarized by the quarter-wave plate layer 109 formed on the surface 103a of the lower substrate 103, and is specularly reflected by the light reflection layer. At this time, the polarization of the reflected light is reversed, passes through the quarter-wave plate layer 109 again, and becomes a component having a vibration plane parallel to the major axis direction of the molecules of the dichroic dye 105. Since this component is absorbed by the dichroic dye 105, a complete black display is obtained. On the other hand, when a voltage is applied, the nematic liquid crystal molecules 104a are vertically oriented along the direction of the electric field, and the dichroic dye 105 is similarly oriented. Light incident from the upper substrate 102 side passes through the guest-host liquid crystal layer 104 without being absorbed by the dichroic dye 105, and further passes through the light reflection layer 108 without being affected by the quarter-wave plate layer 109. Specularly reflected. The reflected light passes through the quarter-wave plate layer 109 again, and the guest-host liquid crystal layer 10
At 4, the light is emitted without being absorbed. Therefore, white display is obtained.

[0005]

In the above-described conventional structure, a vapor deposition film of a metal such as aluminum is incorporated as the light reflection layer 108. The light reflecting layer 108 is in a substantially mirror state, and has an extremely strong directivity because the light is regularly reflected. Therefore, the brightness of the display changes extremely depending on the viewing angle in relation to the external illumination light. For this reason, there is a problem that the display is extremely difficult to see. Further, the light reflecting layer 109 in a mirror surface state has a metallic appearance and is not always suitable as a background for display.

[0006]

The following means have been taken in order to solve the above-mentioned problems of the prior art. That is, the reflection type guest-host liquid crystal display device according to the present invention has, as a basic configuration, a first substrate disposed on the incident side, and joined to the first substrate via a predetermined gap and disposed on the reflection side. A second substrate; a guest-host liquid crystal layer positioned in the gap;
A light diffusion layer interposed between the substrate and the guest host liquid crystal layer, a light reflection layer interposed between the second substrate and the guest host liquid crystal layer, and a light reflection layer interposed between the guest host liquid crystal layer and the light reflection layer. A quarter-wave plate layer interposed between the first substrate side and the second
Electrodes formed on the substrate side to apply a voltage to the guest-host liquid crystal layer. As a characteristic feature, the light reflecting layer has a periodic structure and scatters and reflects incident light entering from the first substrate side, while the light diffusing layer diffuses reflected light that travels backward from the light reflecting layer. The light is transmitted and emitted. Preferably, the light reflection layer includes a resin film having a periodic uneven structure and a reflection film formed on the surface thereof. For example, the resin film is a photosensitive resin film having an uneven structure patterned by photolithography. Further, the light reflection layer may include a hologram having a periodic lattice structure and a reflection film formed on the back surface thereof. Preferably, the light diffusion layer comprises a transparent resin film and fine particles dispersed therein. In this case, the transparent resin film may be colored and have a function as a color filter.

According to another aspect of the present invention, a reflection type guest-host liquid crystal display device has a basic structure in which a first substrate disposed on an incident side is bonded to the first substrate via a predetermined gap. A second substrate disposed on the reflection side, a guest host liquid crystal layer positioned in the gap, a light reflection layer interposed between the second substrate and the guest host liquid crystal layer, and the guest host liquid crystal layer. And a quarter-wave plate layer interposed between the light reflection layer and the light reflection layer, and electrodes formed on the first substrate side and the second substrate side, respectively, for applying a voltage to the guest host liquid crystal layer.
As a characteristic feature, the light reflection layer is made of a hologram and has a light scattering property. Preferably, a light diffusion layer is interposed between the first substrate and the guest host liquid crystal layer. For example, the light diffusion layer includes a transparent resin film and fine particles dispersed therein. The transparent resin film may be colored and have a function as a color filter.

According to the present invention, the light reflection layer built in the reflection type guest-host liquid crystal display device has a periodic structure,
It has light scattering properties. Unlike the conventional mirror light reflection layer, the incident light is scattered and reflected, and light is emitted in a relatively wide angle range.
Therefore, the observer can visually recognize a clear display in a relatively wide viewing angle range, can significantly improve the brightness of the display, and can easily view the display. Further, unlike the metallic appearance of the conventional mirror light reflection layer, the light reflection layer having light scattering properties has a so-called paper white appearance and is preferable as a display background. As a specific configuration, the light reflection layer according to the present invention includes a resin film having a periodic uneven structure formed thereon and a reflection film formed on the surface thereof. Alternatively, the light reflection layer according to the present invention comprises a hologram having a periodic lattice structure and a reflection film formed on the back surface thereof. In such a light reflecting layer having a periodic structure, interference or diffraction may occur with incident light in some cases. When interference or diffraction occurs, the intensity distribution and wavelength distribution of the reflected light have an angle dependence. For this reason, there is a possibility that luminance unevenness and color unevenness appear on the display depending on the viewing angle. Therefore, in the present invention, the light diffusion layer is provided on the incident side substrate, and the reflected light that has traveled backward from the facing light reflection layer is diffusely transmitted and emitted. Due to this diffusion action, the viewing angle dependence of the reflected light is reduced, and a display without luminance unevenness or color unevenness can be realized. That is, in the present invention, by disposing the light diffusion layer on the substrate side facing the light scattering layer having the periodic structure, the unevenness in brightness and unevenness in color depending on the viewing angle is improved. Furthermore, by using a combination of a hologram and a specular reflection film as a light reflection layer having scattering properties, the degree of light scattering with respect to incident light can be freely controlled. Especially,
When combined with the light diffusing layer, the coloring characteristic of the hologram can be improved, the display appearance can be whitened, and the viewing angle dependency can be reduced. Further, by using both the light diffusion layer and the color filter, the process of forming the light diffusion layer can be substantially omitted.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic partial sectional view showing a first embodiment of a reflection type guest-host liquid crystal display device according to the present invention. As shown, the reflective guest-host liquid crystal display device includes a first substrate 1 disposed on the incident side and a second substrate joined to the first substrate 1 via a predetermined gap and disposed on the reflective side. 2 has a panel structure. A guest-host liquid crystal layer 3 is held in a gap between the substrates 1 and 2. The guest-host liquid crystal layer 3 is mainly composed of nematic liquid crystal molecules 4 and contains a black dichroic dye 5. A color filter 30, a light diffusion layer 25, an electrode 6, and an alignment film 7 are sequentially formed on the inner surface of the incident side substrate 1. The light diffusion layer 25 is interposed between the incident side substrate 1 and the guest host liquid crystal layer 3. On the other hand, on the inner surface of the substrate 2 on the reflection side, a light reflection layer 9, a planarization layer 14, a quarter-wave plate layer 10, an electrode 11, and an alignment film 15 are formed in this order. The light reflection layer 9 is interposed between the lower substrate 2 and the guest host liquid crystal layer 3. The quarter-wave plate layer 10 is interposed between the light reflection layer 9 and the guest-host liquid crystal layer 3. The electrodes 6, 11 formed on the incident side substrate 1 and the reflecting side substrate 2, respectively, apply a voltage to the guest host liquid crystal layer 3 to perform a desired display. The alignment films 7 and 15 formed on the upper and lower substrates 1 and 2 respectively horizontally align the guest-host liquid crystal layer 3.

As a feature of the present invention, the light reflecting layer 9 has a periodic structure, and scatters and reflects the incident light entering from the upper substrate 1. On the other hand, the light diffusion layer 25 diffusely transmits reflected light that has traveled backward from the light reflection layer 9 and emits the reflected light. In the present embodiment, the light reflection layer 9 includes a resin film 9a having a periodic uneven structure and a reflection film 9b formed on the surface thereof. This resin film 9a is a photosensitive resin film having an uneven structure patterned by photolithography. The surface of the light reflecting layer 9 having a physical uneven structure is covered with a flattening layer 14, on which a quarter-wave plate layer 10 is formed. On the other hand, the light diffusion layer 25 is composed of a transparent resin film and fine particles dispersed therein. As the fine particles, glass beads or plastic beads having a refractive index significantly different from that of a transparent resin film can be used.

As described above, the light diffusion layer 9 has a physical uneven structure and has a light scattering property. Therefore, not only is the paper white appearance preferable as a display background, but also the incident light is reflected in a relatively wide angle range, so that the viewing angle is enlarged and the display is easy to see, and the brightness of the display is increased in a wide viewing angle range. . However, light reflected from the light reflecting layer 9 having the periodic structure may cause interference or diffraction due to the periodic structure, and the color may change depending on the viewing angle. As a result, display quality may be slightly impaired. That is, light incident from a certain direction on the light reflection layer 9 having a repetitive structure such as unevenness causes interference and diffraction depending on the incident angle and the wavelength. As a result, color unevenness and luminance unevenness occur depending on the viewing angle. In order to reduce such viewing angle dependency, in the present invention, the transmission type light diffusion layer 25 is disposed on the incident side substrate 1 facing the reflection side substrate 2. The light diffusion layer 25 is a coating film in which plastic beads or glass beads are dispersed in a transparent resin film (matrix polymer), and can remove or suppress interference and diffraction.

FIG. 2 is a schematic partial sectional view showing a reference example of the reflection type guest-host liquid crystal display device. Parts corresponding to those of the reflection type guest-host liquid crystal display device according to the present invention shown in FIG. 1 are denoted by corresponding reference numerals to facilitate understanding. In this reference example, the light reflection layer 9 having a periodic structure is formed on the lower substrate 2, but no light diffusion layer is formed on the upper substrate 1. In this case, due to the periodic structure of the light reflection layer 9, interference or diffraction occurs at light incident from a certain angle, and the intensity distribution and the spectral distribution of the reflected light have an angle dependency. In this reference example, since the light diffusion layer for reducing the angle dependence is not provided, the incident angle dependence of the intensity distribution and the spectral distribution of the reflected light becomes uneven in the brightness and color of the display, and thus becomes closer to the observer. It will be visually recognized.

Next, a method of manufacturing the light reflecting layer 9 shown in FIG. 1 will be described with reference to FIG. First, as shown in FIG. 1A, a photosensitive resin film 9a is applied to the entire surface of a substrate 2 made of glass or the like. As the photosensitive resin film 9a, for example, a photoresist can be used. Next, as shown in (B), the photoresist is exposed and developed through a mask on which a predetermined periodic pattern is drawn, and a resin film 9 is formed.
a is patterned into, for example, periodically arranged cylinders. Subsequently, as shown in (C), the substrate 2 is subjected to a heat treatment to reflow the resin film 9a. By this reflow, the photoresist column is gently deformed, and a desired uneven shape is obtained. As shown in (D), a reflective film 9b of aluminum or the like having a desired film thickness and good reflectance is formed on the uneven surface of the resin film 9a formed as described above by vacuum evaporation or the like. By setting the depth dimension of the unevenness to several μm, good light scattering characteristics can be obtained, and the reflective film 9b exhibits white. When the pitch of the periodic structure of the resin film 9a is on the order of μm or sub-μm, interference or diffraction occurs depending on the incident angle because it approaches the wavelength of visible light. In order to alleviate this phenomenon, a light diffusion layer 25 is provided on the substrate 1 on the opposite side. Subsequently, as shown in (E), the unevenness on the surface of the reflection film 9b is filled with the flattening layer 14. The flattening layer 14 is formed of a transparent organic material such as an acrylic resin, and is applied by spin coating or the like. Finally, as shown in FIG.
4 is coated with a polymer liquid crystal material. The flattening layer 14
Has been subjected to a rubbing treatment in advance. The polymer liquid crystal is, for example, a side-chain polymer liquid crystal using a benzoate ester mesogen as a pendant. This polymer liquid crystal material is composed of cyclohexanone and methyl ethyl ketone in an 8 to 2 ratio.
3 to 5% by weight in the mixed solution. This solution is spin-coated at a rotation speed of, for example, 1000 rpm to form a polymer liquid crystal on the flattening layer 14. Thereafter, the substrate is heated to once heat the polymer liquid crystal to an optically isotropic state. Subsequently, the heating temperature is gradually lowered to return to a room temperature state through a nematic phase. In the nematic phase, the polymer liquid crystals are arranged along the rubbing direction of the base, and a desired uniaxial orientation can be obtained. This uniaxial orientation state is
Is fixed by returning to room temperature. By such an annealing treatment, the liquid crystal molecules contained in the polymer liquid crystal material are uniaxially oriented, and a desired quarter-wave plate layer 10 is obtained. On this, an electrode 11 made of a transparent conductive film such as ITO is formed. Further, an alignment film 15 is formed thereon. The alignment film 15 is made of, for example, a polyimide resin, and can be rubbed along a desired direction, whereby horizontal alignment of the guest-host liquid crystal layer in contact therewith can be realized.

FIG. 4 is a schematic partial sectional view showing a second embodiment of the reflective guest-host liquid crystal display device according to the present invention. Parts corresponding to those in the first embodiment shown in FIG. 1 are denoted by corresponding reference numerals to facilitate understanding. In the present embodiment, the light reflection layer 9 includes a hologram 9c having a periodic lattice structure and a reflection film 9b formed on the back surface thereof. As the hologram 9c, a volume phase type or the like can be used, and a desired light scattering property can be obtained by appropriately controlling the phase at the formation stage. For example, light scattering can be realized in a viewing angle range corresponding to an actual use state, and a certain degree of directivity can be provided. As described above, when the hologram 9c is used, the light reflection layer 9 having directivity corresponding to the viewing angle range on the observer side can be easily obtained. However, since the hologram 9c has a periodic lattice structure, it may emit strong light in a specific direction, and the spectral distribution and the intensity distribution may have extreme viewing angle dependence. Therefore, as in the first embodiment, a transmissive light diffusion layer 25 is disposed on the inner surface of the substrate 1 on the opposite side. This light diffusion layer 25
Thus, it is possible to reduce luminance unevenness and color unevenness caused by diffraction and interference.

FIG. 5 is a graph showing the viewing angle dependence of luminance in the reflection type guest-host liquid crystal display device according to the second embodiment shown in FIG. The horizontal axis represents the viewing angle with the normal direction being 0 degrees, and the vertical axis represents the luminance on a relative scale. The curve connecting the white points indicates the measurement result when the hologram and the light diffusion layer are combined, and the curve connecting the black points indicates the measurement result when only the hologram is used. still,
In this luminance measurement, an integrating sphere light source is used. As is clear from the graph, the viewing angle characteristics can be improved by combining the hologram and the light diffusion layer. That is, when the hologram and the light diffusion layer are combined, even if the viewing angle is far away from the normal direction, the luminance does not decrease significantly.

Finally, a specific embodiment of the reflection type guest-host liquid crystal display device according to the present invention will be described in detail with reference to FIG. As shown in the figure, the present display device is configured using a pair of upper and lower substrates 1 and 2 joined to each other with a predetermined gap therebetween. The upper substrate 1 is located on the incident side and is made of a transparent base material such as glass. On the other hand, the lower substrate 2 is located on the reflection side, and it is not always necessary to use a transparent material. A guest host liquid crystal layer 3 is held in a gap between the pair of substrates 1 and 2. The guest-host liquid crystal 3 is mainly composed of nematic liquid crystal molecules 4 having negative dielectric anisotropy and contains a black dichroic dye 5 at a predetermined ratio. Upper substrate 1
A colored light diffusion layer 25a, a counter electrode 6, and an alignment film 7 are formed in this order on the inner surface. The colored light diffusion layer 25a is composed of a transparent resin film and fine particles dispersed therein, and the transparent resin film is colored and has a function as a color filter. In other words, by dispersing fine particles such as plastic beads and glass beads in the color filter, it is not necessary to provide a light diffusion layer separately from the color filter, which leads to rationalization of the manufacturing process. The counter electrode 6 is made of a transparent conductive film such as ITO. The alignment film 7 is made of, for example, a polyimide film, and vertically aligns the guest-host liquid crystal layer 3. The present invention is not limited to this, and the guest-host liquid crystal layer may be horizontally aligned as shown in FIGS. In this embodiment, the guest-host liquid crystal layer 3 is vertically aligned when no voltage is applied, and shifts to horizontal alignment when a voltage is applied.

On the lower substrate 2, a switching element comprising a thin film transistor 8, a light reflection layer 9, a quarter-wave plate layer 10, and a pixel electrode 11 are formed. As a basic configuration, the quarter-wave plate layer 10 is formed above the thin film transistor 8 and the light reflection layer 9, and has a contact hole 12 communicating with the thin film transistor 8. The pixel electrode 11 is patterned on the quarter-wave plate layer 10. Therefore, a sufficient electric field can be applied to the guest host liquid crystal layer 3 between the pixel electrode 11 and the counter electrode 6. This pixel electrode 11 is electrically connected to the thin film transistor 8 via a contact hole 12 opened in the quarter-wave plate layer 10.

Hereinafter, each element will be specifically described. In this embodiment, the quarter-wave plate layer 10 is composed of a uniaxially oriented polymer liquid crystal film. A base alignment layer 13 is used to uniaxially align the polymer liquid crystal film.
A flattening layer 14 is interposed to fill in the unevenness of the thin film transistor 8 and the light reflecting layer 9, and the above-described underlying alignment layer 13 is formed on the flattening layer 14. Then, the quarter-wave plate layer 10 is also formed on the surface of the flattening layer 14. In this case, the pixel electrode 11 is the quarter-wave plate layer 1
0 and the thin film transistor 8 through the contact hole 12 provided through the planarizing layer 14. The light reflection layer 9 is subdivided corresponding to each pixel electrode 11. Each of the subdivided portions is connected to the same potential as the corresponding pixel electrode 11. With such a configuration,
An unnecessary electric field is not applied to the quarter-wave plate layer 10 or the flattening layer 14 interposed between the light reflection layer 9 and the pixel electrode 11. The light reflection layer 9 has a periodic structure as shown in the figure, and has a scattering reflective surface. Thereby, the image quality is improved by preventing the specular reflection of the incident light. Further, in addition to the light reflection layer 9, a light diffusion layer 25a is provided on the side of the substrate 1 facing the light reflection layer 9 to reduce unevenness in brightness and color caused by the periodic structure of the light reflection layer 9. An alignment film 15 is formed so as to cover the surface of the pixel electrode 11, and the guest-host liquid crystal layer 3
And its orientation is controlled. In this embodiment, the alignment film 15 and the opposing alignment film 7 together vertically align the guest-host liquid crystal layer 3. Finally, the thin film transistor 8 has a bottom gate structure, and the gate electrode 16, the gate insulating film 17, and the semiconductor thin film 18
Are laminated. The semiconductor thin film 18 is made of, for example, polycrystalline silicon, and a channel region aligned with the gate electrode 16 is protected from above by a stopper 19. The bottom gate type thin film transistor 8 having such a configuration is covered with an interlayer insulating film 20. A pair of contact holes are opened in the interlayer insulating film 20, through which the source electrode 21 and the drain electrode 2 are formed.
2 is electrically connected to the thin film transistor 8. These electrodes 21 and 22 are, for example, patterned aluminum. The drain electrode 22 has the same potential as the light reflection layer 9. The pixel electrode 11 is electrically connected to the drain electrode 22 through the contact hole 12 described above. On the other hand, a signal voltage is supplied to the source electrode 21.

[0019]

As described above, according to the present invention,
In a reflection type guest-host liquid crystal display device having a built-in light reflection layer having a periodic structure, by disposing a light diffusion layer on a substrate on the incident side, it is possible to suppress luminance unevenness and color unevenness and obtain a high-quality image. Will be possible. When a combination of a hologram and a specular reflection film is used as the light reflection layer, the control of the light scattering characteristics becomes easy and free. Also in this case, by providing the light diffusion layer on the substrate on the incident side, it is possible to obtain a reflective guest-host liquid crystal display device with high viewing angle dependence and high luminance. Further, by dispersing the transparent fine particles in the color filter, it is not necessary to separately provide a light diffusion layer, and the manufacturing process of the reflection type guest-host liquid crystal display device can be simplified.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a first embodiment of a reflective guest-host liquid crystal display device according to the present invention.

FIG. 2 is a partial cross-sectional view showing a reference example of a reflective guest-host liquid crystal display device.

FIG. 3 is a process chart showing a method of forming a light reflection layer incorporated in the reflection type guest-host liquid crystal display device shown in FIG.

FIG. 4 is a partial sectional view showing a second embodiment of the reflective guest-host liquid crystal display device according to the present invention.

FIG. 5 is a graph showing viewing angle characteristics of a reflective guest-host liquid crystal display device according to a second embodiment.

FIG. 6 is a partial sectional view showing an embodiment of a reflection type guest-host liquid crystal display device according to the present invention.

FIG. 7 is a partial cross-sectional view illustrating a conventional reflective guest-host liquid crystal display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Substrate, 3 ... Guest host liquid crystal layer, 6 ... Electrode, 9 ... Light reflection layer, 10 ... Quarter wave plate layer, 11 ... Electrode, 14 ... Flattening layer, 25 ... Light diffusion layer , 30 ... Color filter

Claims (10)

[Claims] 1. A first substrate arranged on an incident side, a second substrate joined to the first substrate via a predetermined gap and arranged on a reflection side, and a guest-host liquid crystal layer located in the gap When,
A light diffusion layer interposed between the first substrate and the guest host liquid crystal layer; a light reflection layer interposed between the second substrate and the guest host liquid crystal layer; A reflective guest-host liquid crystal comprising a quarter-wave plate layer interposed between reflective layers, and electrodes formed on the first substrate side and the second substrate side, respectively, for applying a voltage to the guest host liquid crystal layer. A display device, wherein the light reflecting layer has a periodic structure and scatters and reflects incident light entering from a first substrate side, while the light diffusing layer reflects reflected light traveling backward from the light reflecting layer. Reflective guest-host liquid crystal display device, which diffusely transmits and emits light. 2. The reflection type guest-host liquid crystal according to claim 1, wherein the light reflection layer comprises a resin film having a periodic uneven structure formed thereon and a reflection film formed on the surface thereof. Display device. 3. The reflection-type guest-host liquid crystal display device according to claim 2, wherein the resin film is a photosensitive resin film having an uneven structure patterned by photolithography. 4. The reflection-type guest-host liquid crystal display device according to claim 1, wherein said light reflection layer comprises a hologram having a periodic lattice structure and a reflection film formed on a back surface thereof. 5. The reflection type guest-host liquid crystal display device according to claim 1, wherein said light diffusion layer comprises a transparent resin film and fine particles dispersed therein. 6. The reflective guest-host liquid crystal display device according to claim 5, wherein the transparent resin film is colored and has a function as a color filter. 7. A first substrate arranged on the incident side, a second substrate joined to the first substrate via a predetermined gap and arranged on the reflection side, and a guest-host liquid crystal layer located in the gap When,
A light reflection layer interposed between the second substrate and the guest host liquid crystal layer, a quarter-wave plate layer interposed between the guest host liquid crystal layer and the light reflection layer, A reflective guest-host liquid crystal display device comprising: a light-reflecting layer formed of a hologram and having a light-scattering property. A reflective guest-host liquid crystal display device, characterized in that: 8. A light diffusion layer interposed between the first substrate and the guest host liquid crystal layer.
The reflective guest-host liquid crystal display device as described in the above. 9. The reflection type guest-host liquid crystal display device according to claim 8, wherein said light diffusion layer comprises a transparent resin film and fine particles dispersed therein. 10. The reflective guest-host liquid crystal display device according to claim 9, wherein the transparent resin film is colored and has a function as a color filter.