WO2000057240A1

WO2000057240A1 - Liquid crystal display

Info

Publication number: WO2000057240A1
Application number: PCT/JP1999/001403
Authority: WO
Inventors: Yoshiaki Nakamura; Masayoshi Fujieda; Koji Ishii
Original assignee: Hitachi, Ltd.; Hitachi Device Engineering, Co., Ltd.
Priority date: 1999-03-19
Filing date: 1999-03-19
Publication date: 2000-09-28

Abstract

A liquid crystal display of which the size, thickness, and weight are small. The display has a light diffusing layer which is provided in the display part and made of adhesive (17) and a light diffusing material (16) having a different refractive index from that of the adhesive (17).

Description

[Technical field]

The present invention relates to a liquid crystal display device (that is, a liquid crystal display module), and more particularly to a reflection type liquid crystal display device that reflects an external light to display an image.

[Background technology]

In today's highly information-oriented society, there is a high demand for obtaining necessary information anytime and anywhere, and the demand for portable information processing devices 47 as shown in Fig. 16 is increasing. .

The portable information processing device 47 is required to be small and lightweight, to be thin, and to be capable of being driven by a battery for a long time. Therefore, the display device 46 of the portable information processing device 47 can be made a small, lightweight and thin display device, and when there is external light such as sunlight, auxiliary lighting is not required and power consumption can be reduced. For this reason, the reflection type liquid crystal display device 46 is optimal.

However, even today, there is a strong demand for smaller, thinner, and lighter portable information processing devices 47, and accordingly, there is a growing need for smaller, thinner, and lighter reflective liquid crystal display devices 46. .

An object of the present invention is to provide a thin liquid crystal display device.

Another object of the present invention is to provide a lightweight liquid crystal display device.

Another object of the present invention is to provide a small liquid crystal display device.

Another object of the present invention is to provide a liquid crystal display device having a simple structure and good display characteristics.

Another object of the present invention is to provide a high contrast display with a simple structure. The object of the present invention is to provide a liquid crystal display device which can obtain the following.

Another object of the present invention is to provide a reflection type liquid crystal display device which can obtain a high reflectance with respect to external light with a simple structure.

Another object of the present invention is to provide a reflective liquid crystal display device having a simple structure and capable of recognizing a display even in a dim place.

Another object of the present invention is to provide a liquid crystal display device having a simple structure and low power consumption.

Another object of the present invention is to provide a liquid crystal display device that can be manufactured with a small number of members.

Another object of the present invention is to provide a liquid crystal display device which is easy to manufacture.

Still another object of the present invention is to reduce the cost of a liquid crystal display device.

Further, there is still room for improvement in the display image quality of the reflection type liquid crystal display device as compared with the transmission type liquid crystal display device.

Therefore, another object of the present invention is to provide a reflective liquid crystal display device having a high display contrast.

Another object of the present invention is to provide a reflective liquid crystal display device having a high reflectivity and good light use efficiency.

A well-known example of a reflection type liquid crystal display device provided with an auxiliary lighting device is disclosed in Japanese Patent Application Laid-Open No. Hei 10-32615. However, in the above-mentioned known examples, the configuration of the light diffusion layer, the relationship between the optical axes of various optical films, and the optimal numerical values of the retardation (Δη · d) were not described.

[Disclosure of the Invention]

In a reflection type liquid crystal display device, a light diffusing film is used to improve the viewing angle characteristics of display. FIG. 2 is a sectional view showing a reflection type liquid crystal display device using a light diffusion film. Since the same reference numerals are used as those in FIG. 1 described later, detailed description of the reference numerals is omitted.

The external light L1 traveling to the liquid crystal display device 46 passes through the specific pixel electrode 4a, is reflected by the reflective layer 2 and becomes the reflected light L2, passes through the light diffusion film 12a, and is reflected by the liquid crystal display device 46. Go outside.

The reflected light L2 that has passed through the light diffusion film 12a generates diffused light L3 that diffuses in various directions.

Therefore, an observer observing the liquid crystal display device from any direction can recognize the display by looking at the diffused light L3.

On the other hand, as shown in FIG. 3, in the case of a reflective liquid crystal display device without a light diffusion film, the reflected light L2 is emitted only in a specific direction.

Therefore, in the reflective liquid crystal display device, if there is no member that scatters light in various directions, such as the light diffusion film 12a, the observation of the liquid crystal display device 46 from a place other than the path of the reflected light L2 is performed. Cannot recognize the display.

As described above, in the reflection type liquid crystal display device, a member that scatters light, such as the light diffusion film 12a, is indispensable to make the display easier to see.

However, if a thick light-diffusing film is used for the light-scattering member, it becomes difficult to reduce the size, thickness, and weight of the liquid crystal display device.

In addition, demands for further improvement in the display characteristics of a reflection type liquid crystal display device such as a contrast / reflectance ratio have recently been increasing.

In order to solve the above-mentioned problems, the present invention provides a light diffusion layer 11a provided on a display portion of a liquid crystal display device with an adhesive 17 as shown in FIG. 1a and FIG. 1b. 17 and a light diffusing material 16 having a different refractive index. In order to improve the display image quality of the reflection type liquid crystal display device, as shown in FIG. 6, the reflection spectral characteristics 34 of the light reflection layer 2 and the transmission spectral characteristics 35 of the light diffusion layer 11 a of the liquid crystal display panel 35 a Optimized.

In order to improve the display image quality of the reflective liquid crystal display device, the liquid crystal display panel and the retardation of each retardation plate (the value of the refractive index anisotropy Δn and the Product of thickness d. Sometimes called Δη · d.

In order to further improve the display image quality of the reflective liquid crystal display device, the optical axes (stretching axis, polarizing axis) 38 of the polarizing plate 12b and the optical axes of the first retardation plate 12c are shown in FIG. 39, the optical axis 40 of the second retardation plate 12 d, the incident light-side alignment axis of the liquid crystal display panel (the alignment axis of the liquid crystal layer 9 on the side in contact with the second substrate 5, or the second The relationship between the alignment axis 37 and the emission light side alignment axis (the alignment axis of the liquid crystal layer 9 in contact with the first substrate 1 or the first alignment axis of the liquid crystal layer) 36 is expressed by the second substrate 5 The angle between the optical axis 40 of the second retardation plate 12 d that contacts the liquid crystal layer 9 and the alignment axis 36 of the liquid crystal layer 9 on the output light side is in the range of 30 ° to 80 °, and contacts the polarizing plate 12 b side. The angle between the optical axis 39 of the first retardation plate 1 2c and the orientation axis 36 of the liquid crystal layer 9 on the output light side is in the range of 60 ° to 130 °, and the optical axis of the polarizing plate 12b is The angle between the axis 3 8 and the alignment axis 3 6 of the liquid crystal layer 9 on the exit light side is 7 The angle between the alignment axis 36 of the liquid crystal layer 9 on the exit light side and the alignment axis 37 of the liquid crystal on the incident light side is set to 240 ° or more, and the retardation of the liquid crystal layer 9 is set within the range of 0 ° to 150 °. An'd is 0.7 0m to 0.95〃m, and the retardation Δηd of the second retardation plate 12 d is 13 nm to 250 nm, and the first The retardation Δη · d of the phase difference plate 12 c was optimized to be between 380 nm and 500 nm.

According to the present invention, the light diffusion layer 1 la provided in the display section of the liquid crystal display device is constituted by the adhesive 17 and the light diffusion material 16 having a different refractive index from the adhesive 17. This eliminates the need for a light-diffusing film, making it possible to reduce the thickness, size, and weight of the liquid crystal display device.

According to the present invention, as shown in FIG. 6, the transmission spectral characteristic 35a of the light diffusion layer 11a is flattened like the reflection spectral characteristic 34 of the light reflection layer 2 of the liquid crystal display panel. By doing so, the reflectance characteristics of the liquid crystal display device can be improved. Therefore, it is possible to provide a liquid crystal display device having good light use efficiency. Further, according to the present invention, by optimizing the retardation Δη · d of the liquid crystal display panel and each of the retardation plates, a liquid crystal having a high contrast characteristic can be provided. A display device can be provided.

According to the present invention, the optical axis 38 of the polarizing plate 12b, the optical axis 39 of the first retardation plate 12c, and the optical axis 4 of the second retardation plate 12d shown in FIG. 0, by optimizing the relationship between the incident-light-side alignment axis 37 and the outgoing-light-side alignment axis 36 of the liquid crystal display panel, the first retardation plate 12 c and the second retardation plate 12 d It is possible to provide a liquid crystal display device having high contrast characteristics even if the retardation varies.

[Brief description of drawings]

FIG. 1a is a sectional view of a liquid crystal display device according to an embodiment of the present invention, and FIG. 1b is an enlarged view of a portion I in FIG. 1a.

FIG. 2 is a cross-sectional view of a reflective liquid crystal display device using a light diffusion film.

FIG. 3 is a cross-sectional view of a reflective liquid crystal display device without a light diffusion filter, and FIGS. 4a to 4e are views showing the appearance of a liquid crystal display device according to an embodiment of the present invention.

Fig. 5a is a sectional view taken along the line A-A in Fig. 4a, and Fig. 5b is a sectional view of Fig. 4a. Fig. 5c is a cross-sectional view taken along a line C-C in Fig. 4a, and Fig. 5d is a cross-sectional view taken along a line D-D in Fig. 4a.

FIG. 6 is a diagram showing the spectral characteristics of the reflective layer and the adhesive containing the diffusing material. FIG. 7 is a diagram for explaining an angle relationship among an absorption axis of a polarizing plate, a stretching axis of a first retardation plate, and a stretching axis of a second retardation plate in one embodiment of the present invention. is there.

FIG. 8 is a diagram showing a change in the contrast ratio of the display of the liquid crystal display device with respect to the fluctuation of the retardation (Δη · d) of the phase difference plate.

FIG. 9 is a diagram showing a change in the reflectance of external light of the liquid crystal display device with respect to a change in retardation of the phase difference plate.

FIG. 10 is a sectional view of a liquid crystal display device according to a second embodiment of the present invention. .

FIG. 11 is a sectional view 0 "of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 12 is a sectional view of a liquid crystal display device according to a fourth embodiment of the present invention.

FIG. 13 is a sectional view of a liquid crystal display device according to a fifth embodiment of the present invention.

FIG. 14 is a sectional view of a liquid crystal display device according to a sixth embodiment of the present invention.

FIG. 15 is a sectional view of a liquid crystal display device according to a seventh embodiment of the present invention.

FIG. 16 is a perspective view showing the appearance of an information processing device using the liquid crystal display device of the present invention.

[Best Mode for Carrying Out the Invention]

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings described below, components having the same function are denoted by the same reference numerals, and the description thereof will not be repeated.

First embodiment.

In this embodiment, an illumination device including a light guide 13 and a linear light source 14 such as a fluorescent lamp or an LED and an input device 15 such as a sunset panel are installed on a reflective liquid crystal display panel.

A first aluminum thin film or Ranaru reflective layer 2 on the inner surface of the substrate 1, S i 0 ₂ such as a protective film 3 made of anti-oxidation film of, ITO (Indium Tin oxide) transparent conductive film such as a lower glass substrate The lower electrode (signal electrode) 4 is formed.

In addition, on the inner surface of the second substrate 5 which is the upper glass substrate, a color filter 6 of three colors (R, G, B) obtained by adding a dye or a pigment to an organic resin film, and impurities from the color filter 6 to the liquid crystal layer 9 are formed. A protective film 7 made of an organic material and a top electrode (scanning electrode) 8 made of a transparent conductive film such as ITO are formed to prevent contamination of the second substrate 5 and planarize the inner surface of the second substrate 5. A light-shielding film (black matrix) in the form of a lattice or stripe is formed between the colors R, G, and B of the color filter 6 as necessary, and the protective film 7 is formed thereon.

A liquid crystal layer 9 made of a liquid crystal composition is injected between the first and second substrates 1 and 5, and sealed with a sealing material 10 such as an epoxy resin to form a liquid crystal display panel.

On the outside (upper side) of the second substrate 5, which is the substrate on the observer side of the liquid crystal display panel, a polarizing plate 12b, a first retardation plate 12c, and a second retardation plate 12d are provided. It is laminated. Second substrate 5, Polarizer 1 2b, First retarder 1 An adhesive layer (eg, an epoxy-based adhesive) or an adhesive layer 11 such as an adhesive is provided between 2c and the second retardation plate 12d, and each member is fixed. Have been. Here, the adhesive means an adhesive capable of attaching the optical films 12 again, even if the various optical films 12 are once adhered and then peeled off. By fixing various optical films 12 and liquid crystal display panels together using an adhesive, if the optical film 12 is fixed by mistake, reproduction becomes possible, improving the production yield of liquid crystal display devices. I can do it.

The reflective layer 2 preferably has a specular reflectivity in terms of reflectance. In the present embodiment, an aluminum film is formed by an evaporation method. A multilayer film for improving the reflectance may be formed on the surface of the reflective layer 2, and a protective film 3 is formed thereon for the purpose of protecting the reflective layer 2 against corrosion and flattening the surface.

The reflective layer 2 is not limited to aluminum, and may be a metal film such as silver or silver as long as it is a film having specular reflectivity, or a non-metal film. Further, the protective film 3 is not limited to the SiO ₂ film, but may be any insulating film that protects the reflective layer 2, such as an inorganic film such as a silicon nitride film, an organic metal film such as an organic titanium film, or a polyimide.有機 An organic film such as epoxy may be used. In particular, an organic film such as polyimide or epoxy is excellent in flatness, and the lower electrode 4 formed on the protective film 3 can be easily formed. When an organic metal film such as an organic titanium film is used for the protective film 3, the lower electrode 4 can be formed at a high temperature, and the wiring resistance of the lower electrode 4 can be reduced.

Above the liquid crystal panel on which the multilayer optical film 12 is installed, a light guide 13 and a light source 14 are provided as an illumination device used when there is little external light. The light guide 13 is made of a transparent resin such as acrylic resin, and the surface (top surface) on the observer side is subjected to a printing pattern or irregularities for emitting the light L 4 of the light source 14 to the liquid crystal display panel side. Have been. Further, an input device 15 such as a sunset panel is provided above the lighting device. The input device 15 detects the position of the pressed portion by pressing the surface of the input device 15 with a pointed stick or a finger like a pen, and detects the position of the pressed portion. It outputs a data signal to send to 0.

The second substrate 5, the light guide 13 and the input device of the liquid crystal display panel are fixed with a double-sided adhesive tape (for example, a nonwoven fabric impregnated with an adhesive) or the like. By using a double-sided adhesive tape, it can be peeled off after being pasted once, so that it can reproduce even if the liquid crystal display panel, lighting device and input device are fixed by mistake.

Note that when lighting and data input are not required, the lighting device and the input device 15 may not be provided, and the lighting device and the input device 15 may be added to the liquid crystal display panel as needed.

In the present embodiment, the adhesive layer 11a provided between the first retardation plate 12c and the second retardation plate 12d has a light diffusion function. Specifically, as shown in FIG. 1b, a light diffusing material 16 having a different refractive index from the adhesive 17 is mixed into the adhesive 17. Light is scattered in the adhesive layer 11a because the adhesive 17 and the diffusing material 16 have different refractive indexes. Adhesive 17 and diffusing material 16 need only have different refractive indices.If epoxy-acrylic adhesive is used for adhesive 17, transparent material such as polyethylene, polystyrene, divinylbenzene, etc. is used for diffusing material 16. Organic particles and transparent inorganic particles such as silicide can be used. If the refractive index of the adhesive 17 is different from that of the diffusing material 16, the adhesive described above may be used. In that case, the first retardation plate 12 c is erroneously used and the second adhesive is used. Even if it is pasted on the phase difference plate 1 2 c, it can be reproduced. By using transparent inorganic or organic particles for the diffusion material 16, the absorption in the visible light region is small, so that the reflectance and spectral characteristics of the liquid crystal display device can be improved. . Further, when the adhesive 17 is an organic substance, the difference in coefficient of thermal expansion can be reduced by using organic particles for the diffusing material 16, so that cracks are generated in the adhesive layer 11a. Not even.

When the diffusing material 16 is mixed into the adhesive 17, cracks may be easily generated in the adhesive layer 11 a as compared with the case where only the adhesive 17 is used. Since the adhesive layer 11 a containing the light diffusing material is provided between the first retarder 12 c and the second retarder 12 d having substantially the same ratio, the adhesive 11 1 a There is no problem of cracking.

《Principle of image display》

Next, the display principle of the liquid crystal display device of the present embodiment will be described.

External light (incident light) L 1 radiated from various directions, such as sunlight, is input device 15, light guide 13, polarizing plate 1 b that transmits only light of a specific polarization axis, Adhesive layer 11 for fixing polarizing plate 12b to 1st retarder 12c, 1st retarder 12c, 2nd retarder 12d to 1st retarder Adhesive layer 11 1a having a light diffusion function for fixing 12 c, second retarder 12 d, adhesion for fixing second retarder 12 d to second substrate 5 The light reaches the reflective layer 2 through the layer 11, the second substrate 5, the color filter 6, the upper electrode 8, the liquid crystal layer 9, and a specific pixel electrode (or specific signal line) 4 a. The external light L1 that has reached the reflective layer 2 is reflected and becomes reflected light L2, and has a specific pixel electrode 4a, a liquid crystal layer 9, an upper electrode 8, and a color filter 6 in a path opposite to that of the incident light L1. , The second substrate 5, the adhesive layer 11, and the light diffusing through the second retardation plate 12 d that converts the reflected light L 2 into light that easily transmits through the polarizing plate 12 using the birefringence effect. The functional adhesive layer reaches 1a.

The reflected light L2 entering the adhesive layer 11a is scattered in various directions to generate scattered light L3. The direct reflection light L2 and the scattered light L3 emitted from the adhesive layer 11a compensate for the phase difference generated when light passes through the liquid crystal layer 9 using the birefringence effect. The light is emitted to the outside of the liquid crystal display device through the first retardation plate 12 c, the adhesive layer 11, the polarizing plate 12 b, the light guide 13, and the input device 15. The observer can recognize the display controlled by the specific pixel 4a by looking at the directly reflected light L2 and the scattered light L3 emitted outside the liquid crystal display device.

《Adhesive layer with light diffusion function》

In the present embodiment, since the adhesive layer 11a for fixing the first retardation plate 12c to the second retardation plate 12d has a light diffusion function, the path of the directly reflected light L2 An observer in a place other than the above can recognize the display by the scattered light L3, so that the viewing angle characteristics of the liquid crystal display device are good.

Further, since the light diffusion film 12a becomes unnecessary, the liquid crystal display device can be made thinner, smaller, and lighter. Further, since the light diffusion film 12a is not required, the structure of the liquid crystal display device is simplified, and the productivity is improved.

In this embodiment, the adhesive layer 11a having a light diffusion function preferably has a haze value of 60% to 90%. The haze value H is given by Equation 1 where Tt is the total light transmittance and Td is the diffuse transmittance.

H = T t / T d X 1 0 0 Equation 1

If the haze value H of the adhesive layer 11a is smaller than 60%, the amount of diffused light L3 decreases and the viewing angle characteristics deteriorate. If the haze value H of the adhesive layer 11a is larger than 90%, the light transmittance of the adhesive layer 11a becomes poor, and the reflectance of the liquid crystal display device decreases.

When the adhesive layer 11 a having the light diffusion function is used as in this embodiment, the difference in the refractive index between the adhesive 17 and the diffusion material 16, the dispersion density of the diffusion material 16, and the particle size of the diffusion material 16 By adjusting d, the haze value H can be easily set to an optimum value. In the case of using an epoxy or acrylic adhesive for the adhesive 17 and transparent beads (spherical) made of an organic resin such as divinylbenzene for the diffusing material 16, the sphere diameter d of the diffusing material 16 is 3 〃 n! ~ 10 1 m When set, a high contrast of 6 or more can be obtained.

When the transmission spectral characteristics of the adhesive layer 11a having the light diffusion function are matched with the reflection spectral characteristics of the reflective layer 2, the reflectance of the liquid crystal display device is improved.

Figure 6 shows the reflection spectral characteristics 34 of the reflective layer 2, the transmission spectral characteristics 35a of the flat type light diffusing adhesive layer, and the transmission spectral characteristics 35b of the non-flat type light diffusing adhesive layer. It is.

The reflection spectral characteristic 34 of the reflective layer 2 in the visible light region shows a substantially constant flat characteristic regardless of the wavelength of light.

The transmission spectral characteristic 35a of the flat type light diffusing adhesive layer is also adjusted to a substantially constant flat characteristic in the visible light region.

The transmission spectral characteristics 35b of the non-flat type light diffusing adhesive layer show characteristics in which the transmittance increases as the wavelength becomes longer because the spectroscopic characteristics are not particularly adjusted.

As shown in 35b, the transmittance of a general adhesive greatly changes depending on the wavelength. The longer the wavelength, the higher the transmittance.

*: Corresponds to the sign of the diffusion material shown in Fig. 6. Table 1 shows the contrast and ON of the liquid crystal display device, with the light diffusion adhesive layer of the flat type 35a and the light diffusion adhesive layer of the non-flat type 35b. of time This is data comparing reflectance and reflectance at OFF. The data in Table 1 used the flat type 35a and the non-flat evening 35b with the same haze value H of the light diffusing adhesive layer of 78% to explain the difference in spectral characteristics. . As is evident from Table 1, the contrast of the liquid crystal display device and the reflectance at the time of ON are improved with the light diffusing adhesive layer of the flat type 35a which is close to the spectral characteristics of the reflective layer 2. With respect to the reflectance at OFF, the flat type 35a is slightly lower than the non-flat type 35b, but the reflectance at 0FF is low, and the black display is deeper, so the contrast is higher. Will be higher.

In the above description, the visible light region is set to a wavelength region of 400 to 760 nm, and the transmittance or reflectance of the flat type is set to within 10% of soil within the visible light region. Contrast C is defined by Equation 2 where V on is the luminance at the maximum gradation display of the liquid crystal display device and V off is the luminance at the lowest gradation display.

C = V on / V off formula 2

According to the present embodiment, since the adhesive layer 11a having a light diffusion function is used for the light diffusion layer, the materials of the adhesive 17 and the diffusion material 16, the dispersion density of the diffusion material 16 and the diffusion material Adjusting the particle size d of 16 makes it easy to match the transmission spectral characteristics of the light-diffusing adhesive layer 1 1a with the reflection spectral characteristics of the reflective layer 2, and provides a liquid crystal display with high reflectivity and high contrast Equipment can be provided. According to the study of the inventors of the present application, as the refractive index of the light diffusing material 16 and the adhesive 17 decreases, and as the diameter d of the light diffusing material 16 decreases, the light diffusing adhesive layer 11 The result is that the spectral characteristics of a become flat. However, if the refractive index of the light diffusing material 16 and the adhesive 17 is reduced, or if the diameter d of the light diffusing material 16 is reduced, display characteristics such as contrast deteriorate, so these parameters are set low. There are limits to what you can do.

In addition, both the first retardation plate 1 2 c and the second retardation plate 1 2 d —Can be composed of films of organic resins such as Bonate, Polyacrylate and Polysulfone.

Therefore, according to the present embodiment, the light diffusing adhesive layer 11 a is provided between the first retardation plate 12 c and the second retardation plate 12 d having a small difference in the coefficient of thermal expansion. Even if a heat shock is applied to the liquid crystal display device, the light diffusing adhesive layer 11a has no cracking force, and the second retardation plate 12d force and the first retardation plate 12c Does not peel. In the present embodiment, the first retardation plate 12 c is also referred to as a retardation compensator, and is provided by the liquid crystal layer 9 to prevent the display from being given a specific color and to enable white display. Things. The second retardation plate 1 2 d is also referred to as a 1 Z 4 wavelength plate, and converts the elliptically polarized light L 2 reflected by the reflective layer 2 into linearly polarized light to produce a reflected light L 2 ゃ divergent light L 3. Are provided to facilitate transmission of the polarizing plate 12b, and are provided to improve the reflectance of the liquid crystal display device.

《Driving method of LCD panel》

In the present embodiment, the display control by the specific pixel 4a is performed in the twisted nematic (TN) mode or the super twisted nematic (STN) mode. In the case of the TN mode, a twisted nematic liquid crystal is used for the liquid crystal layer 9, and in the case of the STN mode, a super twisted nematic liquid crystal is used for the liquid crystal layer 9.

In the liquid crystal layer 9, optical characteristics such as birefringence change due to an electric field formed by the upper electrode 8 and the lower electrode 4. By observing the liquid crystal layer 9 through the polarizing plate 12b, the TN mode and STN mode liquid crystal display devices can observe the change in the optical characteristics of the liquid crystal layer 9 to determine whether the light is transmitted (ON) or not. The display can be controlled as the state (0 FF).

As a method for selecting the specific pixel 4a, a voltage averaging method (multiplex driving method) is used in the present embodiment. The first substrate 1 has a plurality of signal electrodes ( A lower electrode 4 is provided extending in a first direction, and a scanning electrode (upper electrode) 8 is provided on a second substrate 5 in a second direction (for example, a first direction) different from the first direction. The signal electrodes 4 and the scanning electrodes 8 intersect in a matrix when viewed in a plan view. A portion where the signal electrode 4 and the scanning electrode 8 intersect corresponds to one pixel, and a specific pixel electrode is applied by applying a selection voltage to the signal electrode 4 and the scanning electrode 8 corresponding to the specific pixel electrode 4a. 4 You can select a. To control ON / OFF of the selected pixel, a gradation voltage corresponding to ON / OFF may be applied to the signal electrode 4 together with the selection voltage.

<< Relationship of optical axis between liquid crystal display panel and various optical films >>

In the present embodiment, the angle between the extension axis (optical axis) of the second retardation plate 12 d in contact with the second substrate 5 and the alignment axis of the liquid crystal on the emission light side is in the range of 30 ° to 80 °. The angle between the stretching axis (optical axis) of the first retardation plate 12c in contact with the polarizing plate 12b side and the alignment axis of the liquid crystal layer 9 on the emission light side is in the range of 60 ° to 130 °. The angle between the absorption axis b (optical axis, polarization axis or stretching axis) and the alignment axis of the liquid crystal layer 9 on the outgoing light side is in the range of 70 ° to 150 °. The angle of the alignment axis of the liquid crystal on the light side is set to 240 ° or more, the retardation Δηd of the liquid crystal layer 9 is set to 0.7 0m to 0.95〃m, and the retardation of the second retardation plate 12 d High contrast display can be obtained by setting the difference Δη · d to 130 nm to 250 nm and setting the retardation Δn • d of the first retardation plate 12 c to 380 nm to 500 nm.

FIG. 7 is a diagram specifically illustrating the angle relationship between the absorption axis of the polarizing plate, the stretching axis of the first retardation plate, and the stretching axis of the second retardation plate in the present embodiment. is there. FIG. 7 illustrates an STN mode liquid crystal as an example.

In FIG. 7, e-e is a reference line, specifically, the second substrate of the liquid crystal display panel. 5 A line parallel to the long side, f 1 f is a line perpendicular to the e- e line. 36 is the alignment axis on the outgoing light side of the liquid crystal layer 9, 37 is the alignment axis on the incident light side of the liquid crystal layer 9, 38 is the absorption axis of the polarizing plate 12b (optical axis of the polarizing plate), and 39 is the first axis. The extension axis of the phase difference plate 12c (optical axis of the first phase difference plate), and 40 is the extension axis of the second phase difference plate 12d (the optical axis of the second phase difference plate). is there.

4 1 is the angle between the absorption axis of the polarizing plate and the e-e line, specifically 1 25 ± 10 °, and 42 is the angle between the stretching axis 39 of the first retardation plate and the e-e line Specifically, 108 ± 10 °, 43 is the angle between the elongation axis 40 of the second retardation plate and the e-e line, and specifically, 72 ± 10 °, and 44 is The angle (the twist angle of the liquid crystal display panel) formed between the outgoing light-side alignment axis 36 and the incoming light-side alignment axis 37 is 240 ° or more for STN mode liquid crystals, and 45 is the outgoing light-side alignment axis 36 and e. — Specifically set to (360-twist angle 4 4) / 2 [°] with the angle formed by the e-line. In the TN mode, the twist angle 44 should be set to 90 ± 10 °. In addition, when the STN mode liquid crystal is used in this embodiment, a sufficient contrast can be obtained even when the number of the scanning lines 8 is increased, so that a display with high definition can be obtained.

FIGS. 8 and 9 show the display characteristics of the liquid crystal display device when the relationship between the optical axes is set to the relationship described above in the present embodiment.

FIG. 8 shows the relationship between the retardation Δη · d combining the first retardation plate 12 c and the second retardation plate 12 d and the contrast ratio. If the liquid crystal display device is set to the relationship between the optical axes described above, the sum of the retardation Δηd of the first retardation film 12 c and the second retardation film 12 d becomes 6 13 nm. By setting, the maximum contrast ratio can be obtained. Further, even if the retardation Δη · d of the first retardation plate 12 c and the second retardation plate 12 d has a variation of 10 nm in soil, a high contrast ratio of 10 or more can be obtained. FIG. 9 shows the relationship between the retardation Δη · d combining the first retardation plate 12 c and the second retardation plate 12 d and the reflectance. If the liquid crystal display device is set to the relationship between the optical axes described above, the sum of the re-determination Δη · d of the first retardation plate 12 c and the second retardation plate 12 d can be calculated. The maximum reflectance can be obtained by setting to 6 13 nm. In addition, even if the first retardation plate 12c and the second retardation plate 12d have a variation of 10 nm in soil, a high reflectance of 15% or more can be obtained even if there is a variation of 10 nm in soil. can get.

Therefore, in the present embodiment, by optimizing the relationship between the optical axes of the liquid crystal display panel and the various optical films, a high contrast ratio and a high contrast ratio can be obtained even if the characteristics (for example, retardation Δη · d) of the various optical films fluctuate. Since the reflectance can be maintained, a liquid crystal display device having a high production yield can be provided.

In the present embodiment, a spectroscopic method was used to measure the retardation Δη · d of the first retardation plate 12 c and the second retardation plate 12 d. For example, the phase difference plate to be measured is sandwiched between the first and second polarizing films whose polarization axes are perpendicular to each other, and the optical axis to be measured is 45 ° with the polarization axes of the first and second polarizing films. And measure the spectral characteristics of light transmitted through the measurement object and the first and second polarizing films. Since the spectral characteristics of the above-mentioned measurement object and the first and second polarizing films show a minimum value (Bary value) at a specific wavelength λ, the specific wavelength at this time; It is possible to obtain the retardation Δ η · d of Note that the first retardation plate 12c was measured using one first retardation plate 12c, but the second retardation plate 12d was difficult to measure with one sheet. The wavelength spectrum 2 corresponding to the valley value of the three second phase difference plates 12d was measured, and the average value obtained by setting the wavelength spectrum 2 to 1Z3 was used.

《Overall configuration of liquid crystal display device》

FIGS. 4a, 4b, and 4c show more specific examples of this embodiment. , Figure 4d, Figure 4e, Figure 5a, Figure 5b, Figure 5c and Figure 5d

Fig. 4a is a front view from the display side after assembly of the liquid crystal display device 46 is completed, Fig. 4b is a front side view, Fig. 4c is a rear side view, Fig. 4d is a left side view, Fig. 4e is a right side view.

In FIGS. 4a to e, 18 is an upper case (shield case) made of a metal plate of stainless steel, iron, aluminum, or the like, and 20 is a display window provided in the upper case 18. 1 opening. Reference numeral 19 denotes a lower case made of a metal plate such as stainless steel, iron, or aluminum, or a plastic such as polycarbonate or ABS resin.

2 1 is the claw provided on the upper case 18, 2 2 is the hook provided on the upper case 18, and the upper case 18 holds the lower case 1 9 with the claw 21 and the hook 22 and the lower case Combine with 1 9

Reference numeral 14 denotes a light source such as a fluorescent lamp or an LED (Light Emitting Diode). Reference numeral 13 denotes a light guide made of a transparent material such as acryl resin or glass for irradiating the light of the light source 14 to the liquid crystal display panel. The light source 14 and the light guide 13 constitute a lighting device (front light) for supplying light to the liquid crystal display device 46 when external light is small.

Reference numeral 15 denotes an input device (touch panel) for inputting data to be sent to a host (information processing unit) connected to the liquid crystal display device 46.

Reference numeral 12 denotes a light diffusion layer 11 a, a polarizing plate 12 b, a first retardation plate 12 c, a second retardation plate 12 d, etc., provided on a display portion of the liquid crystal display device 46. It is an optical film. The optical film 12 is provided so as to fit within the area of the first opening of the upper case in order to reduce the thickness of the liquid crystal display device 46.

FIG. 5a is a cross-sectional view taken along the line A--A in FIG. 4a, and FIG. 4A is a cross-sectional view taken along line BB of FIG. A, FIG. 5C is a cross-sectional view taken along line C-C of FIG. 4A, and FIG. 5D is a cross-sectional view taken along line DD of FIG. 4A. It is.

The liquid crystal display panel (liquid crystal cell) is formed by bonding a first substrate 1 and a second substrate 5 together. On the side walls of the first substrate 1 and the second substrate 5, a sealing material 31 for sealing the injection hole after injecting the liquid crystal layer 9 into the liquid crystal cell is provided. A second opening 23 is provided in a portion of the upper case 18 corresponding to the sealing material 31 so that the external dimensions of the liquid crystal display device are reduced even if the sealing material 31 protrudes. On the outer surface (upper surface) of the second substrate 5, the various optical films 12 described above are fixed. Around the first substrate 1 and the second substrate 5, a scanning line driving printed circuit board (scanning line driving PCB) 30, a scanning line driving IC chip 28, a flexible printed circuit board (TCP) 29 A driving circuit for a liquid crystal display panel, which is composed of a signal line driving IC chip 32 and a signal line driving printed circuit board (signal line driving PCB) 33, is provided. A signal line driving circuit is configured by the signal line driving IC chip 32, the TCP 29, and the signal line driving PCB 33, and the signal line driving circuit is connected to the signal line 4 of the first substrate 1.

A scanning line driving circuit is constituted by the scanning line driving PCB 30, the scanning line driving IC chip 28 and the TCP 29, and in the case of a matrix type liquid crystal display device using a voltage averaging method, the scanning line driving circuit is Connected to scanning signal line 8 of second substrate 5. In a liquid crystal display device using a thin film transistor (TFT), the scanning lines are provided on the same first substrate 1 as the signal lines, so that the scanning line driving circuit is connected to the first substrate 1. Reference numeral 24 denotes an interface connector for electrically connecting the liquid crystal display device 46 to a host 50 which is an external circuit. In this embodiment, the interface connector 24 may be provided on the signal line driving PCB 33 provided on the scanning line driving PCB 30. Good. Although not shown, the scanning line driving PCB 30 and the signal line driving PCB 33 are electrically connected by connecting means. Reference numeral 26 denotes a spacer for fixing the scanning line driving PCB 30. Reference numeral 27 denotes a spacer for pressing a connection portion between the scanning line driving circuit and the signal line driving circuit and the liquid crystal display panel, and is made of an insulating elastic material such as rubber. 25 is a double-sided adhesive tape, for example, a nonwoven fabric impregnated with an epoxy adhesive can be used. In the present embodiment, the liquid crystal display panel is fixed to upper case 18 with double-sided adhesive tape 25. The double-sided adhesive tape 25 is also used to fix the light guide 13 and the input device 15 to the upper case 18. By fixing each member using the double-sided adhesive tape 25 as in the present embodiment, the assembly of the liquid crystal display device is simplified, and the reproduction can be performed even if each member is fixed by mistake. The manufacturing yield of the device is improved. The lower case 19 is provided with irregularities for holding down the liquid crystal display panel.

<< Application examples of the present invention >>

FIG. 16 is a perspective view showing the appearance of an information processing device 47 using the liquid crystal display device 46 of the present invention.

48 is a display part of the information processing device 47, 49 is a keyboard part of the information processing device 47, 50 is a host that performs information processing of the information processing device 47, 51 is a micro processor, and 5 2 Is a battery, 53 is an interface cable that connects the liquid crystal display device 46 to the host 50, 54 is an inverter power supply for the lighting device, 55 is an inverter power supply 54, and the light source 14 of the lighting device is connected. 5 is a pen for inputting information using the input device 15, 57 is a pen holder for storing the pen 56, 60 is a mobile phone, 61 is a mobile phone and an information processing device This is the cable that connects 4 7.

In the present embodiment, the liquid crystal display device 46 is provided on the display unit 48 of the information processing device 47. According to the liquid crystal display device of the present embodiment, the input device 15 Is superimposed on the display, so pressing a predetermined part with a pen 56 or a finger allows you to enter characters 58 or select the icon 59 to execute the soft-to-air function. I can do it. In addition, since the liquid crystal display device 46 of the present embodiment is of a reflective type, when there is external light such as sunlight, the power consumption can be suppressed by switching off the inverter power supply 54 to reduce the consumption of the battery 52. Can be reduced.

Further, according to the present embodiment, the liquid crystal display device 46 can be made thin, small, and light, so that the information processing device 47 can also be thin, small, and light.

Second embodiment.

FIG. 10 is a sectional view of a liquid crystal display device according to a second embodiment of the present invention. Each reference numeral is the same as the reference numeral in FIG. 1A described in the first embodiment.

The second embodiment is characterized in that an adhesive layer 11a having a light diffusion function is used as an adhesive layer for fixing the second retardation plate 12d to the second substrate 5. Other configurations are basically the same as those of the first embodiment described above.

In this embodiment, since the adhesive layer (light diffusion layer) 11 a having the light diffusion function is located closest to the reflection layer 2 than the other optical films 12 and the adhesion layer 11, the outline of the image Clear display with little blurring.

In a reflection type liquid crystal display device, display is performed using light incident from various directions. For example, as shown in FIG. 10, the incident light L1 and the second incident light L1b incident at an angle different from that of the incident light L1 are reflected by the reflective layer 2, and are reflected by the reflected light L2 and the incident light L2, respectively. A reflected light L 2 b of 2 is generated. Since the emission angles of the reflected light L2 and the second reflected light L2b are different, there is a difference d2 between the positions where the reflected light L2 and the second reflected light L2 pass through the light diffusion layer 11a. . Observer is light diffusion layer Since the image is recognized by looking at the light diffused by 11a, the difference d2 between the positions where the reflected light 2 and L2b pass through the light diffusion layer 11a is δ as the blur of the outline of the image.

However, the closer the light-diffusing layer 11a is to the layer 2, the smaller the difference d2 between the positions of the reflected light L2 and L2b passing through the light-diffusing layer 11a. The blur of the outline of is reduced, and a clearer display is obtained. When a glass substrate is used as the second substrate 5 in the present embodiment, the second retardation plate 12d and the second substrate 5 have a light diffusion function due to a difference in the coefficient of thermal expansion between the glass substrates. Cracks are easily formed in the adhesive layer 11a, but it can be improved by selecting the adhesive 17 and the light diffusing material 16 of the adhesive layer 11a.

Third embodiment.

FIG. 11 is a sectional view of a liquid crystal display device according to a third embodiment of the present invention. Each reference numeral is the same as the reference numeral in FIG. 1A described in the first embodiment.

The third embodiment is characterized in that an adhesive layer 11a having a light diffusion function is used as an adhesive layer for fixing the polarizing plate 12b to the first retardation plate 12c. Other configurations are basically the same as those of the first embodiment described above.

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The polarizing plate 12b is generally composed of an organic resin film such as triacetyl cellulose (TAC). Since the first retardation plate 12c can also be formed of an organic resin film such as polycarbonate, polyacrylate, or polysulfone, the difference in the coefficient of thermal expansion between the first retardation plate 12c and the polarizing plate 12b can be reduced.

In the present embodiment, an adhesive layer 11a having a light diffusion function is provided between the polarizing plate 12b and the first retardation plate 12c, which can reduce the difference in the coefficient of thermal expansion. Therefore, there is no problem of cracks in the adhesive layer 11a, and the reliability of the liquid crystal display device is improved.

Note that, in this embodiment, the light diffusion layer 11a is farther than the reflection layer 2 as compared with the above-described second embodiment, and the above-described reflected lights L2 and L2b are light. The difference d3 between the positions passing through the diffusion layer 11a is increased, and the outline of the displayed image is easily blurred. However, by reducing the thickness of the liquid crystal display panel or the optical film 12, blurring of the outline of the displayed image can be improved.

Fourth embodiment.

FIG. 12 is a sectional view of a liquid crystal display device according to a fourth embodiment of the present invention. Each reference numeral is the same as the reference numeral in FIG. 1A described in the first embodiment.

The fourth embodiment is characterized in that the reflective layer 2 is provided on the outer surface of the liquid crystal display panel, that is, on the surface of the first substrate not facing the liquid crystal layer 9. Other configurations are basically the same as those of the first embodiment described above.

In the present embodiment, the first substrate 1 and the second substrate are attached to each other to form a liquid crystal display panel, and then the reflective layer 2 is provided to complete a reflective liquid crystal display device. The liquid crystal display device can also be used as a liquid crystal display device, so that a liquid crystal display panel can be mass-produced, and a reflective liquid crystal display device with good productivity can be provided.

In the present embodiment, a thin metal plate having good light reflectivity such as stainless steel, chromium, aluminum, silver, or the like is used for the reflective layer 2, and the reflective layer 2 is fixed to the first substrate 1 by the adhesive layer 11. I have. By using the metal plate for the reflective layer 2, it is easy to perform mirror finishing on the reflective layer 2, so that the reflectance can be improved.

The reflection layer 2 is made of a metal such as chromium, aluminum, silver, etc. on the first substrate. 1, it may be formed by vapor deposition such as spattering. When the reflective layer 2 is formed by vapor deposition of a metal, the adhesive layer 11 becomes unnecessary.

Fifth embodiment.

FIG. 13 is a sectional view of a liquid crystal display device according to a fifth embodiment of the present invention. Each reference numeral is the same as the reference numeral in FIG. 1A described in the first embodiment.

In the fourth embodiment, the reflective layer 2 is provided on the outer surface of the liquid crystal display panel, that is, on the surface of the first substrate not facing the liquid crystal layer 9, and between the reflective layer 2 and the first substrate 1. An adhesive layer 11a having a light diffusion function is provided. Other configurations are basically the same as those of the first and fourth embodiments described above.

In the present embodiment, since the light diffusion layer 11a is located closest to the reflection layer 2, the reflected light L2, L2b generated by the difference between the incident angles of the external lights Ll, L2b The difference between the positions passing through the light diffusion layer 11a is minimized, and a clear display image with a clear outline is obtained.

Further, in the present embodiment, similar to the above-described fourth embodiment, the effect that the same thing as the transmissive liquid crystal display device can be used for the liquid crystal display panel and the metallization in which the reflective layer 2 is subjected to the mirror reflection processing are used. The effect is that the board can be used.

Sixth embodiment.

FIG. 14 is a sectional view of a liquid crystal display device according to a sixth embodiment of the present invention. Each reference numeral is the same as the reference numeral in FIG. 1A described in the first embodiment.

The sixth embodiment is characterized in that the reflection layer is also used as the signal electrode 4 and the pixel electrode 4a, that is, the signal electrode 4 and the pixel electrode 4a are formed of a reflective conductive film such as a metal film. I have. Other configurations are basically explained earlier. This is the same as the first embodiment.

In the present embodiment, since a metal film having lower electric resistance than the transparent conductive film can be used for the signal electrode 4 and the pixel electrode 4a, the power supply to the signal electrode 4 and the pixel electrode 4a is improved, and A high-resolution liquid crystal display device having a large number of pixel electrodes 4a and a large-screen liquid crystal display device having a long signal electrode 4 can be provided.

As a material of the signal electrode 4, a metal film such as aluminum, gold, silver, copper, or molybdenum is preferable in terms of low resistivity, and a metal film such as chromium, anolymium, or silver is preferable in terms of light reflectivity. The metal film used for the signal electrode 4 can be formed by an evaporation method such as sputtering.

Although not shown in FIG. 14, in the present embodiment, the light diffusing layer 11a is provided between the pixel electrode 4a and the liquid crystal layer 9 in the same manner as in the fifth embodiment. A clear display image with a clear outline can be obtained.

Seventh embodiment.

FIG. 15 is a sectional view of a liquid crystal display device according to a seventh embodiment of the present invention. Each reference numeral is the same as the reference numeral in FIG. 1A described in the first embodiment.

The seventh embodiment is characterized in that an active matrix liquid crystal display panel using a switching element such as TFT is used for the liquid crystal display panel.

The configuration of the active matrix liquid crystal display panel will be described below, but the configuration not particularly described is basically the same as that of the first embodiment described above.

In the active matrix liquid crystal display panel, as shown in FIG. 15, a plurality of pixels each having a thin film transistor TFT 1 and a pixel electrode 4a are formed on a surface inside a first substrate 1 (liquid crystal side). Each pixel is adjacent Are arranged in the intersection area between two scanning signal lines and two adjacent video signal lines. The thin film transistor TFT 1 includes a gate electrode GT provided on the first substrate 1, a gate insulating film GI provided thereon, a first semiconductor layer (channel layer) AS provided thereon, and a gate electrode GT provided thereon. The second semiconductor layer (semiconductor layer containing impurities) r0 has a source electrode SD1 and a drain electrode SD2 provided thereon. In the present embodiment, the source electrode SD1 and the drain electrode SD2 are formed of a multilayer conductive film of r1 and r2, but may be a single-layer conductive film of only rl. The relationship between the electrodes is reversed depending on how the voltage is applied, and SD2 becomes the source electrode and SD1 becomes the drain electrode. However, in the following description, SD1 will be described as the source electrode and SD2 will be described as the drain electrode for convenience. PSV1 is a protective film made of an insulating film for protecting the thin film transistor TFT1, 4a is a pixel electrode, 0RI1 is the direction of the liquid crystal layer 9 on the first substrate 1 side, 1st alignment film, ORI Reference numeral 2 denotes a liquid crystal layer 9, a second alignment film for aligning the second substrate 5 side, and 8 an upper electrode (common electrode). BM is a light shielding film that shields the thin film transistor TFT1 from light. The BM is also called a black matrix, and also functions to improve the display contrast by blocking light between the pixel electrode 4a and the adjacent pixel electrode. SIL is a conductive film that electrically connects the upper electrode 8 to the terminals (g1, g2, rl, r2, and r3) provided on the first substrate 1. is there.

When a selection voltage is applied to the gate electrode GT, the thin-film transistor TFT 1 becomes electrically conductive between the source electrode SD 1 and the drain electrode SD 2 and functions as a switch, similarly to the insulated gate field-effect transistor. You. The pixel electrode 4a is electrically connected to the source electrode SD1, the video signal line is electrically connected to the drain electrode SD2, and the scanning signal line is electrically connected to the gate electrode. Select the specific pixel electrode 4a with the applied selection voltage, and apply the gradation voltage applied to the video signal line to the specific pixel electrode 4a. Can be supplied. C st is a capacitor electrode and functions to hold the gradation voltage supplied to the pixel electrode 4a until the next selection period.

Active matrix liquid crystal display devices have switching elements such as thin film transistors for each pixel, so there is no problem of crosstalk between different pixels, and crosstalk is eliminated by special driving such as voltage averaging. There is no need to perform, and it is easy to realize multi-gradation display, and the contrast does not decrease even if the number of scanning lines is increased.

In the present embodiment, the pixel electrode 4a is made of a reflective metal film of aluminum, chromium, titanium, tantalum, molybdenum, silver, or the like. Further, in the present embodiment, since the protective film PSVI is provided between the pixel electrode 4a and the thin film transistor TFT1, no malfunction occurs even when the pixel electrode 4a is enlarged and overlaps with the thin film transistor TFT1. It is possible to realize a liquid crystal display device having a high reflectance.

Note that, in the present embodiment, the first embodiment has been described in that the first retarder 12 c is not provided, and the third retarder 12 e for improving the viewing angle characteristics is provided. Different from form. Other configurations of the optical film 12 are the same as those of the first embodiment. The third retardation film 12 e is also called a viewing angle widening film, and is provided for the purpose of improving the angle dependence of the display characteristics of the liquid crystal display device using birefringence characteristics. In the present embodiment, since the third retardation plate 12 e can also be formed of an organic resin film such as polycarbonate, polyacrylate, or polysulfone, the third retardation plate 12 d has the third retardation By using the light diffusion bonding layer 11a as the bonding layer for fixing the plate 12e, it is possible to prevent cracks from being generated in the light diffusion bonding layer 11a.

[Industrial applicability]

INDUSTRIAL APPLICABILITY The present invention is applied to a reflection type liquid crystal display device which performs display using external light such as sunlight when there is external light, and is particularly suitable for a pen input type computer. It can be mounted on the display of such a portable information processing device to reduce the power consumption of the information processing device and reduce the size, thickness, and weight of the information processing device. It is.

Claims

The scope of the claims

1. A liquid crystal display panel having a liquid crystal layer sandwiched between a first substrate and a second substrate; a reflective layer provided on the first substrate for reflecting light; and a polarized light provided on the second substrate. A multi-layer optical film in which a plate and a retardation plate are laminated, wherein a member constituting the multi-layer optical film includes a first adhesive layer for adhering a polarizing plate and a first retardation plate, and a second retardation. A second adhesive layer for bonding the plate and the first retardation plate, and a third adhesive layer for bonding the second retardation plate to the second substrate, wherein the first At least one of the adhesive layer, the second adhesive layer, and the third adhesive layer is a light-diffusing adhesive layer obtained by mixing particles having a different refractive index from the adhesive into the adhesive. Liquid crystal display device.

2. The liquid crystal display device according to claim 1, wherein an auxiliary light source for illuminating the upper surface of the liquid crystal display panel and an input device for inputting data are provided on the multilayer optical film.

3. The liquid crystal display device according to claim 1, wherein a color filter film is provided on an inner surface of one of the first substrate and the second substrate.

4. A liquid crystal display panel having a liquid crystal layer sandwiched between a first substrate and a second substrate; a reflection layer provided on the first substrate for reflecting light; and a light provided on the second substrate. Having a diffusion layer,

A liquid crystal display device, wherein a transmission spectral characteristic of a visible light region of the light diffusion layer is matched with a reflection spectral characteristic of a visible light region of the reflection layer.

5. The liquid crystal display device according to claim 4, wherein an auxiliary light source for illuminating the upper surface of the liquid crystal display panel and an input device for inputting data are installed on the light diffusion layer.

6. The liquid crystal display device according to claim 4, wherein a color filter film is provided on an inner surface of one of the first substrate and the second substrate.

7. A liquid crystal layer is sandwiched between the first substrate and the second substrate, a second retardation plate is provided on the second substrate, and a first phase difference plate is provided on the second retardation plate. A retardation plate, a polarizing plate is provided on the first retardation plate,

When the alignment axis of the liquid crystal layer on the first substrate side is a first liquid crystal alignment axis, and the alignment axis of the liquid crystal layer on the second substrate side is a second liquid crystal alignment axis, the second phase difference The angle between the stretching axis of the plate and the second liquid crystal orientation axis is in the range of 30 to 80 degrees, and the angle between the stretching axis of the first retardation plate and the second liquid crystal orientation axis. In the range of 60 degrees to 130 degrees, the angle between the absorption axis of the polarizing plate and the second liquid crystal alignment axis in the range of 70 degrees to 150 degrees, the first liquid crystal alignment axis And the second liquid crystal alignment axis has an angle of 240 degrees or more, the retardation of the liquid crystal layer is in the range of 0.7 to 0.95 μm, and the first phase difference is A liquid crystal display device, wherein the retardation of the plate is in a range from 130 nm to 250 nm, and the retardation of the second retardation plate is in a range from 380 nm to 500 nm. .

8. The liquid crystal display device according to claim 7, wherein an auxiliary light source for supplying light to the liquid crystal layer and an input device for inputting data are installed on the polarizing plate.

9. The liquid crystal display device according to claim 7, wherein a color filter film is provided on an inner surface of one of the first substrate and the second substrate.