JP2001159756A - Reflection type color liquid crystal device and electronic appliance using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection type color liquid crystal display device having a high opening ratio which enables bright display to be performed. SOLUTION: The figure shows the method of wiring MIM elements in a reflection color liquid crystal device including signal lines 4301, MIM elements 4302 and pixel electrodes 4303. The pixel electrodes are arranged corresponding to the respective R, G, B color filters on a counter substrate. Each dot has a rectangular form, and three sequential dots in the lateral direction make one square pixel. The signal lines are wired parallel to the short sides of the dots, namely, in the lateral direction. By wiring as described above, the number of wires is decreased to increase the opening ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type color liquid crystal device and an electronic apparatus using the same.

[0002]

2. Description of the Related Art A display mounted on a portable information terminal must firstly have low power consumption. Therefore, a reflective liquid crystal device that does not require a backlight is optimal for this application. However, the conventional reflection type liquid crystal device mainly uses a monochrome display, and a satisfactory reflection type color display has not yet been obtained.

The development of a reflective type color liquid crystal device was developed in 1980.
It seems to have begun in earnest since the mid-1980s. Prior to that, there was only a recognition that if a backlight of a transmission type color liquid crystal device was replaced with a reflection plate, a reflection type color display would be possible as disclosed in Japanese Patent Application Laid-Open No. 50-80799. However, as you can see when you actually make it, such a configuration is dark and unusable. There are three causes, one is a polarizing plate and 1 /
The second is that more than two thirds of the light is thrown away by the color filter, and finally the problem of parallax. The problem of parallax cannot be avoided in a TN (twisted nematic) mode or an STN (super twisted nematic) mode generally used in a transmission type liquid crystal device. This is because, in these modes, two polarizing plates are always used, so that a non-negligible gap occurs between the reflecting plate and the liquid crystal layer unless a polarizing plate is formed in the cell. The problem of parallax referred to here refers not only to the problem of double reflection of a display which is also present in a conventional reflective monochrome liquid crystal device, but also to a problem unique to a reflective color liquid crystal device.

[0004] The problem of parallax will be described with reference to the drawings. FIGS. 77A and 77B are cross-sectional views of a reflective color liquid crystal device using a TN mode or an STN mode. This liquid crystal device includes an upper polarizing plate 7701, an upper glass substrate 7702, a liquid crystal layer 7703, a lower glass substrate 7704, a lower polarizing plate 7705, a light reflecting plate 7706, and a red, green, and blue three-color filter 7707. A transparent electrode, an alignment film, an insulating film and the like also exist between the upper and lower glass substrates, but they are omitted because they are not necessary for explaining the problem of parallax. There are two problems of parallax. One of them is the cancellation of colors. In FIG. 77 (a), the observer 771
2 sees the reflected light 7711 that has passed through the green filter, and the light 7713 that passed through the red, green, and blue filters was scattered and reflected by the light reflector, and was mixed. Things. If the thickness of the lower glass substrate is sufficiently thicker than the pitch of the color filters, light that has passed through any color filter will be mixed with equal probability. However, red → green,
Light having passed through the blue-to-green path is absorbed by any one of the color filters and becomes completely dark, leaving only light that has passed through the green-to-green path. The same can be said for the reflected light coming out through the blue or red filter, so that there is a problem that the brightness of the white display is reduced to 1/3 of that when there is no parallax. Another problem is that the color display becomes dark. FIG. 77 (b) shows a green display state.
In addition, a hatched portion in the liquid crystal layer 7703 indicates a non-lighting state (dark state). The incident light 7713 passes through the red, green, and blue dots with equal probability, and 2/3 of them are absorbed by the red and blue dots that are in the off state. Further, after being scattered and mixed by the light reflecting plate, 2/3 are absorbed again by the red and blue dots in the off state, and reach the observer 7712. Therefore, the green display becomes “1/9 of the brightness of the white display minus the absorption of the green filter”, and becomes very dark. It is very difficult to use a TN mode or an STN mode having a parallax problem in a reflective color liquid crystal device.

Therefore, conventionally, an attempt has been made to obtain a bright reflective color display by changing the liquid crystal mode. For example, a paper by Tatsuo Uchida et al. (IEEE Transact)
ions on Electron Devices,
Vol. ED-33, no. 8, pp. 1207-
1211 (1986)). After comparing the brightness of various liquid crystal modes in 2, the PCGH (phase change type guest host) mode which does not require a polarizing plate is adopted. Also, in Japanese Patent Application Laid-Open No. Hei 5-241143, in order to realize a reflective color liquid crystal device, a P-type liquid crystal display device that does not require a polarizing plate is required.
A DLC (polymer dispersed liquid crystal) mode is adopted. The use of a liquid crystal mode that does not require a polarizing plate not only eliminates the absorption of light by the polarizing plate, but also has the advantage that the problem of parallax can be fundamentally eliminated by providing a reflector adjacent to the liquid crystal layer. However, on the other hand, there is a problem that the liquid crystal mode which does not require a polarizing plate generally has a low contrast, and in particular, the PCGH mode has a problem that the halftone display cannot be performed due to the hysteresis of the voltage transmittance characteristic. These liquid crystal modes in which another substance is added to the liquid crystal have many problems in terms of reliability. Therefore, TN mode and STN, which have been widely used in the past and have a proven track record,
If the mode can be used, it is better than this.

Conventionally, attempts have been made to obtain a bright reflective color display using a bright color filter.
Generally, a color filter used in a transmission type color liquid crystal device has a spectral characteristic as shown in FIG. The horizontal axis of FIG. 78 is the light wavelength, and the vertical axis is the transmittance.
801 is the spectrum of the red filter, 7802 is the spectrum of the green filter, and 7803 is the spectrum of the blue filter. The light that humans can perceive is approximately 38
0 nm to 780 nm, especially 450 n
Visibility is high in the wavelength range from m to 660 nm. All of the color filters shown in FIG. 78 have a transmittance of 10% in this range.
%, There are wavelengths that are below%, and a lot of light is wasted. When the value obtained by simply averaging the transmittance in this wavelength range was defined as the average transmittance, the average transmittance of the red filter was 28%, the green filter was 33%, and the blue filter was 30%.

[0007] Brighter color filters are required for use in reflective color liquid crystal devices. Thus, in the above-mentioned paper by Tatsuo Uchida et al., FIG. It has been proposed to use two color filters having a complementary color relationship as shown in FIG. 8 to make the color more bright than in the case of three colors. FIG. 79 shows the spectral characteristics. The horizontal axis of FIG. 79 is the light wavelength, the vertical axis is the reflectance, 7901 is the spectrum of the green filter, and 7902 is the spectrum of the magenta filter. Care must be taken in the comparison because the vertical axis represents the reflectivity, but again from 450 nm to 660 nm.
In the wavelength range of, all the color filters have a transmittance of 10
% Exists. The average transmittance was 41% for the green filter and 48% for the magenta filter.

A paper by Seiichi Mitsui et al. (SID92)
DIGEST, pp. 437-440 (199
2)) also relates to a reflective color liquid crystal device employing the same PCGH mode. 2
, And two bright color filters are used. FIG. 80 shows the spectral characteristics. In FIG. 80, the horizontal axis is the light wavelength, the vertical axis is the reflectance, 8001 is the spectrum of the green filter, and 8002 is the spectrum of the magenta filter. The vertical axis represents the reflectance, but assuming that the square root of the reflectance at each wavelength is the transmittance, at least the transmittance of the green filter is 50% at a wavelength of 470 nm or less.
Less than. The average transmittance was 68% for the green filter and 67% for the magenta filter. In this paper,
Since the reflection plate is provided at a position adjacent to the liquid crystal layer with the color filter interposed therebetween, there is no problem of parallax. Therefore, since light always passes through the color filter twice, sufficient coloring can be ensured even with such a bright color filter.

The color filter proposed in FIGS. 2 (a), 2 (b) and 2 (c) of Japanese Patent Application Laid-Open No. Hei 5-241143 is not a three color filter of red, green and blue, but a yellow filter. ,
Brightness is achieved using three colors, cyan and magenta.
FIG. 81 shows the spectral characteristics. In FIG. 81, the horizontal axis is the light wavelength, the vertical axis is the reflectance, 8101 is the spectrum of the yellow filter, 8102 is the spectrum of the cyan filter, and 8103 is the spectrum of the magenta filter.
It is difficult to make a comparison because the vertical axis represents the reflectance and the axis is not scaled. However, in the wavelength range of 450 nm to 660 nm, the transmittance of all color filters is 10% or less. There is no doubt that wavelengths exist. A rough estimate of the average transmittance was about 0% for the yellow filter, about 60% for the cyan filter, and about 50% for the magenta filter.

As described above, the conventional approach of developing a reflective color liquid crystal device was based on the idea of obtaining a bright display by combining a bright liquid crystal mode without using a polarizing plate and a bright color filter. However, even if it is a bright color filter, 450nm to 660nm
In many cases, a color filter having a wavelength at which the transmittance is less than 10% in the above wavelength range is used.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a reflection type color liquid crystal device capable of providing a bright display by increasing the aperture ratio, and to provide an electronic apparatus using the same.

[0012]

According to a first aspect of the present invention, a pair of substrates having electrodes formed on an inner surface thereof are opposed to each other, and an inner surface of one of the pair of substrates is disposed on the inner surface. In a reflective color liquid crystal device in which a wiring is formed and the electrode formed on the one substrate is connected to the wiring, one of the pair of substrates includes a reflective layer, and the electrode A plurality of the dots form one pixel, and a color filter of a different color is arranged corresponding to each dot constituting the one pixel. The dots constituting the pixel are arranged such that the short side direction is along the wiring.

According to a second aspect of the present invention, there is provided the reflective color liquid crystal device according to the first aspect, further comprising red, blue and green color filters, wherein the red color filters are provided correspondingly. The one pixel is formed by a dot provided with the corresponding blue color filter and a dot provided with the corresponding green color filter.

According to a third aspect of the present invention, there is provided an electronic apparatus including the reflective color liquid crystal device according to the first or second aspect as a display unit.

According to a fourth aspect of the present invention, in the electronic device according to the third aspect, the display unit of the reflective color liquid crystal device can be moved relative to the main body so that ambient light can be efficiently reflected to an observer. It is characterized by being attached to.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The outline of the present invention will be described.
The present invention provides a pair of substrates having electrodes formed on opposing inner surfaces to form a group of dots in a matrix, a liquid crystal interposed between the substrates, a color filter of at least two colors, at least one polarizing plate, A configuration having a reflection plate can be employed. As the liquid crystal mode, a liquid crystal mode using a polarizing plate such as a TN mode or an STN mode can be used.

Further, the thickness of the substrate located on the reflection plate side of the pair of substrates may be 200 μm or more. More preferably, the thickness of the substrate located on the reflection plate side can be set to 700 μm or more. In other words, the thickness of the substrate located on the reflection plate side can be 1.25 times or more of the shorter of the dot pitch in any of the vertical and horizontal directions, and more preferably 4 times or more. With such a configuration, there is an advantage that a high contrast can be secured by the effect of parallax even if the driving area ratio is small.

Conventionally, for example, in Japanese Patent Publication No. 3-64850, the thickness of the lower substrate of the reflection type monochrome liquid crystal device is set to 30.
It is proposed that the thickness be 0 μm or less. Certainly, in the reflection type monochrome display, the lower substrate is preferably as thin as possible from the viewpoint of reducing double images (shadow). However, in the reflection type color display, it is desired to widen the interval between dots from the viewpoint of brightening the color display. If the space between the dots is wide, the contrast is inevitably reduced. However, if the lower substrate is sufficiently thick, a high contrast can be secured by the shadow effect of the adjacent pixels.

Further, among the color filters, at least one color filter has a wavelength of 450 nm to 660 nm.
Has a transmittance of 50% or more for light of all wavelengths in the range. More preferably, the color filters of at least two colors are from 450 nm to 660 nm.
It is possible to have a transmittance of 50% or more for light of all wavelengths in the range of m. More preferably,
Any of the color filters can have a transmittance of 50% or more for light of all wavelengths in the range of 450 nm to 660 nm. Most preferably, any color filter can have a transmittance of 60% or more for light of all wavelengths in the range of 450 nm to 660 nm. In other words, any of the color filters can have an average transmittance of 70% or more with respect to light having a wavelength in the range of 450 nm to 660 nm. More preferably, any of the color filters can have an average transmittance of 75% or more and 90% or less for light having a wavelength in the range of 450 nm to 660 nm.

The transmittance of the color filter referred to here is the transmittance of the color filter alone, not including the transmittance of the glass substrate, the transparent electrode, the overcoat, and the undercoat. When the density of the color filter has a distribution, or when the color filter is provided only in a part of the dot, the average transmittance in the dot is defined as the transmittance of the color filter. With this configuration, the reflective color liquid crystal device has an advantage that a bright color can be displayed. Conventionally, for example, in the claims of Japanese Patent Application Laid-Open No. 7-239469, each of the color filters has a transmittance of 80% or more in a light transmission region and a transmittance of 50% in a light absorption region.
It is as follows. According to the embodiment, the transmittance of the light absorbing region is only 20 to 30%. In such a color filter, if a liquid crystal mode using a polarizing plate is used, the display becomes dark, which is not practical.

Further, the color filter may be composed of three colors of red, green and blue, and one of the red or blue color filters may be orange or cyan. . However, the orange filter has a wavelength of at least 570 nm to 66 nm.
70% or more, preferably 75% for light in the range of 0 nm
% Or more. Further, the cyan filter is characterized in that it has a transmittance of at least 70%, preferably at least 75% for light in the wavelength range of 450 nm to 520 nm. With this configuration, the reflective color liquid crystal device can
There is an advantage that bright white and bright colors can be displayed.

The color filter comprises three colors of red, green and blue, and the minimum transmittance of the red color filter for light having a wavelength in the range of 450 nm to 660 nm is blue, green or blue. It is characterized in that it is smaller than the minimum transmittance of the color filter of the system for light having a wavelength in the range of 450 nm to 660 nm. More preferably, the blue and green color filters have a transmittance of 50% or more for light of all wavelengths in the range of 450 nm to 660 nm. More preferably, the blue color filter is cyan. With such a configuration, the reflective color liquid crystal device has an advantage that it can display bright, small-colored white and also can display vivid red. Since red is the color stimulus that most appeals to the human eye, it is very preferable to display red with emphasis.

Further, the color filter is provided only in a part of a light modulatable area in each dot. With such a configuration, the reflection type color liquid crystal device of the present invention has an advantage that color mixing due to parallax can be reduced while the conventional color filter manufacturing technology can be used. In particular, when a color filter is provided at a position between the electrode and the liquid crystal, a wide viewing angle is obtained,
There is an advantage that color purity in halftone is improved. Conventionally, for example, Japanese Patent Publication No. 7-62723 proposes providing a color filter on a part of a dot.
This is a transmissive liquid crystal device, which is different from the present invention in that it is limited to a color filter using a dyeing method, and the area where a color filter is provided is as large as 67% to 91% of a dot.
(The expression in Japanese Patent Publication No. 7-62723 states that “the area of the non-colored portion is 10 to 50% of the area of the colored portion.” Therefore, the area of the colored portion to be converted into dots is 100/150 = 6.
From 7%, 100/110 = 91%. )

Further, a transparent layer in the visible light region is formed to have a thickness substantially equal to that of the color filter in a region where no color filter is provided in the light modulatable region and in a region where light modulation is not possible. And With this configuration, the reflection type color liquid crystal device has an advantage that high-quality display can be performed without disturbance of liquid crystal alignment.

Further, the invention is characterized in that the color filters are provided only for the dots whose number is not more than 3/4 of the total number of dots. More preferably, it is characterized in that the dots are provided only for two-thirds or less of the total number of dots. With this configuration, a bright display is possible, and also in the case of displaying a halftone color, if the brightness is adjusted mainly with dots without a color filter, there is an advantage that a vivid color can always be displayed. is there. Traditionally,
In a transmissive liquid crystal device, one pixel is formed by four dots of red, green, blue, and white, but it has never been proposed for a reflective liquid crystal device. Especially TN mode and STN
In the reflective color liquid crystal device using the mode, the problem of parallax is inevitable, and it becomes very dark when performing color display,
By providing dots without color filters,
Bright color display is possible.

The color filters may be arranged so that adjacent dots have different colors. This indicates so-called mosaic arrangement or triangle arrangement, and conversely, stripe arrangement does not fall within this range. With such a configuration, there is an advantage that the phenomenon that the degree of coloring varies depending on the viewing angle is reduced, particularly when there is parallax. Conventionally, for example, Japanese Patent Application Laid-Open No. Hei 8-87009 proposes a vertical stripe arrangement in claim 6 thereof. Also, Japanese Patent Application Laid-Open No. 5-241143 states that there is no fundamental difference between the stripe arrangement and the staggered arrangement in the right column, line 17 to line 18, page 6 of the specification. In addition, a paper by Tatsuo Uchida et al. (IEEE Transactions
on Electron Devices, Vol.
ED-33, no. 8, pp. 1207-1211
(1986)). In No. 1, a mosaic-arranged color filter is employed, but this is a case where a reflective electrode is provided in a cell, and there is no parallax, which is different from the present invention.

Further, the color filter may be provided over the entire effective display area. This configuration has the advantage that the display looks bright. The “effective display area” is defined as “a drive display area and a subsequent area effective as a screen” in ED-2511A of the Electronic Industries Association of Japan (EIAJ) standard. Normally, in a transmissive color display, a color filter is provided only in a drive display area, and a black mask made of metal or resin is provided in an area outside the drive display area. However, in a reflective color display, a metal black mask cannot be used because it is glaring. In addition, the cost of the resin black mask is increased because the original color filter is not provided with the black mask. However, if nothing is provided outside the driving display area, the outside becomes bright and the driving display area looks relatively dark. Therefore, it is effective to provide the same color filters as those inside the driving display area, preferably in the same pattern.

Further, the black mask may not be provided in the area outside each dot, and instead, a color filter having absorption equal to or smaller than the area in the dot may be provided. This configuration means that no black mask or color filter overlap is provided outside the dots. Also, it means that a color filter is provided not partially but entirely or partially, entirely. With this configuration, there is an advantage that a bright display can be obtained. this is,
In particular, when there is parallax, the brightness of the display is almost proportional to the square of the aperture ratio, so that it becomes very dark when a black mask is provided. It is because it falls.
Conventionally, for example, in JP-A-59-198489, a color filter is provided only on a pixel electrode, and nothing is provided outside the color filter. Japanese Patent Application Laid-Open No. 5-241143 describes both the case with and without the black mask, but there is no middle point between them.

Further, a color filter may be provided on an outer surface of the substrate located on the reflection plate side of the pair of substrates. This configuration has the advantage that it can be provided at low cost. In addition, by combining this configuration with a configuration in which the color filter is provided only in a part of the light modulatable area in each dot, there is an advantage that an assembly margin is enlarged and a viewing angle is widened.

Further, a non-linear element may be provided corresponding to each dot on the inner surface of the substrate located on the reflection plate side of the pair of substrates. With such a configuration, there is an advantage that unnecessary surface reflection is reduced and high contrast is obtained.

A non-linear element may be provided corresponding to each dot on the inner surface of one of the pair of substrates, and may be connected in a direction parallel to the short side of the dot. Usually, especially in a data display for a PC, dots are often vertically long, and the direction parallel to the short sides of the dots is the horizontal direction (horizontal direction). With such a configuration, there is an advantage that an aperture ratio is increased and a bright display is obtained. This is particularly effective when a black mask is not provided, and when a reflective configuration having parallax is used.

Further, the driving area ratio can be set to 60% or more and 85% or less. Here, the driving area ratio is
It is defined as the ratio of the region where the liquid crystal is driven in the region excluding the opaque portion such as the metal wiring and the MIM element in the pixel. With this configuration, there is an advantage that a bright color display can be obtained while ensuring the contrast.

Further, the reflector has a scattering characteristic such that when a light beam enters the reflector, 80% or more of the light is reflected in a 30-degree cone centered on the specular reflection direction. can do. Preferably, it is possible to have a scattering characteristic such that 95% or more of the light is reflected in a 30-degree cone. With this configuration, there is an advantage that a bright display can be obtained. Conventionally, for example, in Japanese Patent Application Laid-Open No. 8-87009, a reflector having directivity with a half-value width of 30 degrees is used on page 6, right column, lines 43 to 44 of the specification. When the half width is 30 degrees, the scattering characteristic is such that approximately 30% of light is reflected in a 30-degree cone, roughly calculated, and the scattering is too large as compared with the present invention. With such characteristics, the display becomes dark and is not practical.

Further, the reflection plate may be a transflective plate, and a backlight may be provided on the back surface. Preferably, the reflection plate has an intensity of 80% of incident light.
The above is reflected. With such a configuration, there is an advantage that the image can be seen even in a dark environment.

Further, the liquid crystal may be a nematic liquid crystal twisted by about 90 degrees, and two polarizing plates may be arranged so that their transmission axes are orthogonal to the rubbing directions of the adjacent substrates. This is the Japanese Patent Publication No. 51-01366
The TN mode proposed in Japanese Patent Application Laid-Open Publication No. HEI 9-205, is applied to a reflection type color liquid crystal device. With this configuration, the reflective color liquid crystal device has advantages of being bright, having high contrast, and having a wide viewing angle.

The birefringence Δn of the liquid crystal and the thickness d of the liquid crystal layer
Is greater than 0.34 μm and 0.52 μm
m. More preferably, Δn × d can be set to 0.40 μm or more and 0.52 μm or less. Most preferably, △ nx
d can be 0.42 μm. With this configuration, the reflective color liquid crystal device can
There is an advantage that it is bright and has a wide viewing angle.

In the conventional reflection type monochrome liquid crystal device, the second minimum condition with little coloring, that is, Δn × d is 1.1
Conditions of about μm to 1.3 μm were used. However, in the reflection type color liquid crystal device, since a little coloring can be compensated for by the color filter, it is not necessary to adopt the second minimum condition. Further, in Japanese Patent Application Laid-Open No. 8-87009, the condition of Δn × d = 0.55 μm is adopted as shown in the specification, page 5, lines 27 to 29. However, under this condition, the color is darker and the coloring is larger than the condition where Δn × d is larger than 0.34 μm and smaller than 0.52 μm.

The liquid crystal may be a nematic liquid crystal twisted by 90 degrees or more, and may have a structure in which two polarizing plates and at least one retardation film are arranged. If possible, it is desirable to perform multi-line simultaneous selection driving according to the method disclosed in Japanese Patent Application Laid-Open No. 6-348230. With such a configuration, there are advantages of low cost and brightness.

Further, the reflector is provided between a pair of substrates,
A configuration in which only one polarizing plate is provided can be employed. This is an application of a single polarizer type nematic liquid crystal mode proposed in Japanese Patent Application Laid-Open No. 3-223715 to a reflection type color liquid crystal device. With this configuration, there is an advantage that a bright color with high color purity can be displayed.

Further, the reflection plate may be a mirror reflection plate, and a scattering plate may be provided on the outer surface of the substrate located on the incident light side. With this configuration,
There is an advantage that a bright color with high color purity can be displayed.

Further, the liquid crystal on the metal wiring can be configured to be oriented similarly to the liquid crystal in the pixel portion. This configuration has the advantage of being bright.

The display can be of a normally white type. This configuration has the advantage of being bright.

Further, one dot can constitute one pixel. This configuration has the advantage that the resolution can be increased during monochrome display.

Further, the electronic apparatus of the present invention can be configured to include a reflection type color liquid crystal device as a display unit. With this configuration, the electronic device has the advantages of low power consumption, thinness and light weight, and good visibility even under direct sunlight.

Further, the display unit may be configured to be movable with respect to the main body so that ambient light can be reflected to the observer efficiently. With this configuration, there is an advantage that a bright display can be obtained under any lighting conditions.

As can be understood from the above description, the present invention is characterized by utilizing a liquid crystal mode using a polarizing plate and combining this with a bright color filter.
Although there are many liquid crystal display modes using a polarizing plate, the purpose of the present invention is to provide a liquid crystal display mode capable of bright and black-and-white display, such as the TN mode proposed in Japanese Patent Publication No. 51-113666 and Japanese Patent Publication No. 3-50249. Patent Document 1: Japanese Patent Laid-Open No. Hei 3-2237
No. 15, a one-polarizer-type nematic liquid crystal mode proposed in JP-A-6-235920, and a nematic liquid crystal mode in which bistable switching is proposed in JP-A-6-235920 are suitable.

In the liquid crystal mode using a polarizing plate, 1/2 or more of the light is discarded only by the presence of the polarizing plate. Therefore, a liquid crystal mode using no polarizing plate should be more suitable for a reflective color liquid crystal device. However, the liquid crystal mode without using a polarizing plate generally has low contrast in both the PCGH mode and the PDLC mode. Therefore, for example, when a pixel is composed of red, green, and blue dots, the contrast is insufficient even if the green dot is set to a bright state and the blue and red pixels are set to a dark state for displaying green. In this case, blue and red are mixed in the green display, and the color purity is reduced. However, in the liquid crystal mode using a polarizing plate, such a phenomenon does not occur because the contrast is high. Therefore, if the same color is displayed, a liquid crystal mode using a polarizing plate can use a color filter with lower color purity. A color filter having low color purity, that is, a bright color filter, should provide a brighter display. Also especially PCGH
Because a normally black display is used, the area between dots becomes black and does not contribute to brightness, and light from a viewing angle direction other than the panel normal direction is absorbed by a dye. Despite that, the brightness is only about 20% higher than in the TN mode. Such a difference in brightness can easily be overcome depending on the color design of the color filter.

Another problem in using the liquid crystal mode using a polarizing plate is the existence of parallax. When only one polarizing plate is used, this problem can be avoided by forming a reflecting plate in the cell, but it cannot be avoided in the TN mode or STN mode using two polarizing plates. Although the parallax has already been described in detail in the section of “Prior Art”, there are two problems. One is the cancellation of the colors, and the other is the darkening of the color display.

The problem of the cancellation of colors is that if the colors of the color filters passed at the time of incidence and the colors of the color filters passed at the time of emission differ, they cancel each other out and become completely dark. That is, it is reduced to 1/3 of the case where there is not. Such a problem arises because the color filter used in the transmission type as shown in FIG. 78 is used as it is. If a bright color filter is used, it will not be completely dark even if it passes through a color filter of a different color.

In addition, the problem of dark color display is that, when displaying a single color, two-thirds of the entire dots are in a dark state. This means that 2/3 is absorbed and only 1/9 of the light is available. This is 1/3 of the brightness when there is no parallax. To solve this, it is necessary to increase the aperture ratio first. Specifically, a black mask is not provided outside the dot, an MIM having only one metal wiring is used, an MIM is arranged in a horizontal direction, and an ST which does not require a metal wiring is used.
We took measures such as using N. Further, by further reducing the driving area ratio, an area (for example, about ２) which is much smaller than 全体 of the whole area when displaying a single color is made dark. In this way, a bright color display is possible even if there is parallax. Means for reducing the driving area ratio or not providing a black mask leads to a decrease in contrast. However, by decreasing the thickness of the lower substrate, the decrease in contrast can be minimized.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a view showing a main part of the structure of a reflection type color liquid crystal device according to Embodiment 1 of the present invention. A pair of substrates, a liquid crystal interposed between the substrates, at least two color filters, and at least one color filter.
It comprises two polarizing plates and a reflection plate. In the figure, 101 is an upper polarizing plate, 102 is a counter substrate, 103 is a liquid crystal, 104 is an element substrate, 105 is a lower polarizing plate, 106
Denotes a scattering reflector, on which a color filter 107 and a counter electrode (scanning line) 108 are provided on a counter substrate 102, and a signal line 109, a pixel electrode 110
An M element 111 was provided. Here, 101, 102, 104
And 105 and 105 and 106 are drawn apart for the sake of clarity of the drawing, and are actually glued together. Further, the space between the opposing substrate 102 and the element substrate 104 is also drawn widely apart, but for the same reason, there is actually only a gap of about several μm to about several tens μm.
Although FIG. 1 shows the main part of the reflection type color liquid crystal device, only 9 dots of 3 × 3 are shown. However, in this embodiment, the number of dots is larger than that of 480 × 640. It may have 307200 dots or more.

The counter electrode 108 and the pixel electrode 110 were formed of transparent ITO, and the signal line 109 was formed of metal Ta.
The MIM element has a structure in which an insulating film Ta ₂ O ₅ is sandwiched between metal Ta and metal Cr. The liquid crystal 103 is a nematic liquid crystal twisted by 90 degrees, and the polarizing axes of the upper and lower polarizing plates are orthogonal to each other. This is a general TN mode configuration. Further, the color filters 107 are composed of two colors of red (indicated by “R” in the figure) and cyan (indicated by “C” in the figure), which are complementary to each other, and are arranged in stripes.

FIG. 2 is a diagram showing the spectral characteristics of the color filter 107. In FIG. 2, the horizontal axis represents the wavelength of light and the vertical axis represents the transmittance, 201 represents the spectrum of the red filter, and 202 represents the spectrum of the cyan filter. The measurement of the spectrum is performed with the counter substrate alone using a microspectrophotometer,
100% transmittance with glass substrate and transparent electrode plus overcoat and undercoat if present
Was corrected. Therefore, the spectral characteristics of the color filter alone are measured. Hereinafter, all the spectral characteristics of the color filters were measured by this method. The transmittance in the present invention is also defined as a value measured by this method. Both the red filter and the cyan filter always show a transmittance of 30% or more in the wavelength range of 450 nm to 660 nm. The average transmittance in the same wavelength range is 52% for the red filter.
%, And the cyan filter was 66%. Since such a color filter has a very light color tone, it is normally more accurate to write "pink" instead of "red". However, in order to avoid confusion, the expression will be unified with pure color below.

The reflective color liquid crystal device prepared as described above has a reflectivity of 24% for white display, a contrast ratio of 1:15, and can display four colors of white, red, cyan and black. The display colors were x = 0.39 and y = 0.32. The cyan display colors were x = 0.28 and y = 0.31. This is about 60% of the brightness of a conventional reflection type monochrome liquid crystal device, and has the same contrast ratio, and is a characteristic that can be sufficiently used under ordinary indoor illumination light or outdoors in the daytime.

In the wavelength range from 450 nm to 660 nm,
A reflective color liquid crystal device using a color filter that exhibits a transmittance of less than 30% at least in some cases requires a special illumination with a dark display or an inadequate white balance to display white. For any reason, cannot withstand normal use.

In the first embodiment, the structure in which the transparent electrode is provided on the color filter is employed. Although the MIM element is used as the active element, this is advantageous in increasing the aperture ratio. Therefore, if the aperture ratio is the same, the effect of the present invention does not change even if a TFT element is used.

(Embodiment 2) FIG. 3 is a diagram showing the spectral characteristics of a color filter of a reflective type color liquid crystal device according to Embodiment 2 of the present invention. The configuration of the second embodiment is the same as that of the first embodiment shown in FIG. 1, and also includes a color filter including two colors of red and cyan. In FIG. 3, the horizontal axis represents the wavelength of light, and the vertical axis represents the transmittance. Reference numeral 301 denotes the spectrum of the red filter, and 302 denotes the spectrum of the cyan filter. Each color filter has a transmittance of 50% or more in a wavelength range of 450 nm to 660 nm. The average transmittance in the same wavelength range was 71% for the red filter and 78% for the cyan filter.

This reflective color liquid crystal device has a reflectivity of 30% for white display, a contrast ratio of 1:15, and can display four colors of white, red, cyan and black, and the red display color is x = 0. .
34, y = 0.32, cyan display color x = 0.29, y
= 0.31. This is a little more than 70% of the brightness of the conventional reflection type monochrome liquid crystal device, and the same contrast ratio.

As described above, when at least one color filter has a transmittance of 50% or more for light of all wavelengths in the range of 450 nm to 660 nm, the environment is substantially the same as that of the conventional reflective monochrome liquid crystal device. Can be used in
A bright reflective color liquid crystal device is obtained. In the case where the color filter is composed of two colors as in the present embodiment, if one of the color filters has a transmittance of 50% or more for light of all wavelengths in the range of 450 nm to 660 nm, a good white color is obtained. In order to obtain a balance, the other color filter necessarily has a transmittance of 50% or more. However, this is not always the case when using color filters of three or more colors. An example will be described later in Example 9.

(Embodiment 3) FIG. 1 is a diagram showing a main part of the structure of a reflective type color liquid crystal device according to Embodiment 3 of the present invention. FIG. 2 is a diagram showing the spectral characteristics of the color filters. In this embodiment, of the pair of substrates, the thickness of the substrate located on the reflection plate side was set to 200 μm or more. The configuration of the third embodiment is basically the same as that of the reflection type color liquid crystal device described in the first embodiment, and the description of each reference numeral is omitted. However, Δn × d of the liquid crystal 103 was set to 0.42 μm.
The dot pitch was 160 μm both vertically and horizontally, and the driving area ratio was 75%.

In Example 3, the thickness of the lower substrate was changed variously. FIG. 4 shows the contrast when the thickness of the element substrate 104 is changed. 4, the horizontal axis represents the element substrate 104.
, The vertical axis is the contrast, 401 is a collection of points indicating the contrast with respect to the thickness of each element substrate 104 in Example 3, and 402 is each element substrate 104 in the comparative example.
Is a group of points indicating the contrast with respect to the thickness of the image.
The display color in color display is x = 0.3 in red display.
9, y = 0.32, x = 0.28 for cyan, y = 0.3
It was around 1.

Since the driving area ratio is 75%, the contrast is at most 10 when the thickness of the element substrate is zero.
Only 0 / (100-75) = 4 can be obtained. However, by setting the thickness of the element substrate 104 to 200 μm or more,
A good contrast of 1:15 or more was obtained by the effect of parallax, that is, the shadow of adjacent dots mitigated light leakage between the dots. Further, by setting the thickness of the element substrate to 700 μm or more, higher contrast could be obtained.

Since the optimum value of the thickness is closely related to the dot pitch, “200 μm or more” and “70
The expression “0 μm or more” means “at least 1.25 times the shorter of the vertical and horizontal dot pitches” and “4 times or more the same”.
It may be expressed.

(Embodiment 4) FIG. 5 is a diagram showing the spectral characteristics of the color filters of the reflection type color liquid crystal device in Embodiment 4 of the present invention. The configuration of the third embodiment is the same as that of the first embodiment shown in FIG.
It has a color filter composed of colors. In FIG. 5, the horizontal axis represents the wavelength of light, the vertical axis represents the transmittance, 501 represents the spectrum of the red filter, and 502 represents the spectrum of the cyan filter. Each color filter is 450nm
In the wavelength range from to 660 nm. The average transmittance in the same wavelength range was 75% for the red filter and 80% for the cyan filter.

This reflective color liquid crystal device has a reflectivity of 31% in white display, a contrast ratio of 1:15, and can display four colors of white, red, cyan and black, and the red display color is x = 0. .
33, y = 0.33, cyan display color x = 0.30, y
= 0.31. This is about 80% of the brightness of the conventional reflection type monochrome liquid crystal device, and the same contrast ratio.

As described above, the color filters of any colors are
If it has a transmittance of 60% or more for all wavelengths in the range of 450 nm to 660 nm, it can be used without any trouble even if input means such as touch keys are mounted on the entire surface of the liquid crystal device. A color liquid crystal device is obtained. However, if a color filter having an average transmittance exceeding 90% in the same wavelength range is used, the display color becomes extremely faint and it becomes difficult to identify the color.

(Embodiment 5) FIG. 6 is a view showing a main part of the structure of a reflective color liquid crystal device according to Embodiment 5 of the present invention. In this embodiment, the color filters are arranged so that adjacent dots have different colors. First, the configuration will be described. 601 is an upper polarizing plate, 602 is a counter substrate, 603 is a liquid crystal, 604 is an element substrate, 605 is a lower polarizing plate, 606
Denotes a scattering reflection plate, on which a color filter 607 and a counter electrode (scanning line) 608 are provided on a counter substrate 602, and a signal line 609, a pixel electrode 610, and a MI are provided on an element substrate 604.
An M element 611 was provided.

The color filter 7 is composed of two colors of red (indicated by "R" in the figure) and cyan (indicated by "C" in the figure) which are complementary to each other. It was arranged to draw a pattern. When the color filters are arranged in a stripe pattern as shown in FIG. 1, the viewing angle characteristics are extremely wide in the vertical direction. This is a phenomenon that occurs because there is a distance between the liquid crystal layer and the color filter layer and the reflection plate by the thickness of the lower substrate (in this case, the element substrate). Experiments have confirmed that such a phenomenon can be considerably reduced by arranging a checkerboard pattern in a mosaic pattern as shown in FIG. In particular, it was also found that color mixing was good even when the number of pixels was relatively small. This is a mosaic arrangement,
It is considered that because the viewing angle direction in which coloring and the viewing angle direction in which color is erased are mixed, at least one of the two eyes looks colored. The color filter had the same spectral characteristics as FIG. 3 of the second embodiment, and the brightness and the contrast ratio were almost the same as those of the second embodiment. Although the example of the mosaic arrangement has been described here, other arrangements such as a triangle arrangement are also effective if adjacent dots have different colors.

(Embodiment 6) FIG. 7 is a diagram showing the spectral characteristics of the color filters of the reflection type color liquid crystal device in Embodiment 6 of the present invention. The configuration of the second embodiment is the same as that of the fifth embodiment shown in FIG. 6, but includes a color filter composed of two colors of green and magenta instead of red and cyan. In FIG. 7, the horizontal axis is the wavelength of light and the vertical axis is the transmittance, 701 indicates the spectrum of the green filter, and 702 indicates the spectrum of the magenta filter. Each color filter has a transmittance of 50% or more in a wavelength range of 450 nm to 660 nm. The average transmittance in the same wavelength range is 76% for the green filter and 78% for the magenta filter.
%Met.

This reflective color liquid crystal device has a reflectivity of 31% in white display, a contrast ratio of 1:17, and can display four colors of white, green, magenta and black, and the green display color is x =
0.31, y = 0.35, magenta display color x = 0.3
2, y = 0.29. This is about 80% of the brightness of the conventional reflection type monochrome liquid crystal device, and the same contrast ratio.

The two colors complementary to each other may be a combination of red and cyan, green and magenta, and a combination of blue and yellow. However, it is more preferable in terms of appearance.

(Embodiment 7) FIG. 8 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to Embodiment 7 of the present invention. First, the configuration will be described. 801 is an upper polarizing plate, 802
Is an opposite substrate, 803 is a liquid crystal, 804 is an element substrate, 805
Is a lower polarizing plate, 806 is a scattering reflector, and the opposite substrate 8
02, a color filter 807 and a counter electrode (scanning line) 808 are provided.
9, a pixel electrode 810, and an MIM element 811. On the upper polarizing plate, a weak anti-glare treatment was applied in order to suppress glare of illumination light.

The color filter 807 is composed of three colors, red (indicated by “R” in the figure), green (indicated by “G” in the figure), and blue (indicated by “B” in the figure). And arranged in a mosaic as shown in the figure.

FIG. 9 is a diagram showing the spectral characteristics of the color filter 807. In FIG. 9, the horizontal axis is the wavelength of light, and the vertical axis is the transmittance. 901 indicates the spectrum of the red filter, 902 indicates the spectrum of the green filter, and 903 indicates the spectrum of the blue filter. Each color filter has a transmittance of 50% or more in a wavelength range of 450 nm to 660 nm. The average transmittance in the same wavelength range was 74% for the red filter, 75% for the green filter, and 63% for the blue filter.

The reflection type color liquid crystal device prepared as described above has a reflectivity of 28% in white display, a contrast ratio of 1:14, a full color display, and a red display color of x.
= 0.39, y = 0.32, green display color x = 0.31,
y = 0.35, blue display color x = 0.29, y = 0.27
Met. This is about 7 of the conventional reflective monochrome liquid crystal device.
It has a relatively high brightness and an equivalent contrast ratio, and can be used to enjoy video images without the need for special lighting.

(Embodiment 8) FIG. 10 shows Embodiment 8 of the present invention.
FIG. 2 is a diagram showing a main part of the structure of a reflective color liquid crystal device in FIG. In this embodiment, among the color filters, at least one color filter has a wavelength of 450 nm to 660 nm.
Has a transmittance of 50% or more for light of all the wavelengths in the range. The color filters are of three colors of red, green and blue, and one of the red or blue color filters is orange or cyan. First, the configuration will be described. 1001 is an upper polarizing plate, 1002 is an element substrate, 1003 is a liquid crystal, 1
004 is a counter substrate, 1005 is a lower polarizing plate, 1006 is a scattering reflector, and a counter electrode (scanning line) 1011 and a color filter 1010 are provided on the counter substrate 1004;
The signal line 1007 and the MIM element 1 are provided on the element substrate 1002.
008, a pixel electrode 1009 was provided. Color filter 1
Reference numeral 010 denotes a pigment dispersion type, which comprises three colors of red (indicated by “R” in the figure), green (indicated by “G” in the figure), and blue (indicated by “B” in the figure). I have.

FIG. 11 is a diagram showing the spectral characteristics of the color filter 1010. The horizontal axis of FIG. 11 is the wavelength of light, the vertical axis is the transmittance, 1101 is the spectrum of the red filter, 11
02 is the spectrum of the green filter and 1103 is the spectrum of the blue filter. 1101, 1102, and 1103 are light color filters, but the images displayed by such color filters are pale. In particular, red and blue are difficult to discriminate because of low visibility. Therefore, a bright color filter that transmits light in a wider wavelength range even when the color slightly changed was used.

When a red filter having low color purity was used in place of the red filter, a very bright red could be displayed although it was slightly orange. The spectrum of this filter is 1
111. This filter has at least a wavelength of 570
It is characterized by having a transmittance of 70% or more, preferably 75% or more for light in the range of nm to 660 nm. When a blue filter having low color purity was used in place of the blue filter, a very bright blue with a slightly cyan color could be displayed. The spectrum of this filter is 111
3 is shown. This filter has a wavelength of at least 450 nm
It is characterized by having a transmittance of 70% or more, preferably 75% or more, for light in the range of 520 nm to 520 nm. However, when such a color filter is used, the white display tends to be bluish or reddish. Therefore, when using the above color filter, it is desirable to adjust the color balance in combination with a green filter having higher color purity. An example of a green filter having high color purity is shown at 1112. This filter is characterized by having a transmittance of 70% or more only for light in the wavelength range of 510 nm to 590 nm.

(Embodiment 9) FIG. 12 shows Embodiment 9 of the present invention.
FIG. 4 is a diagram illustrating spectral characteristics of a color filter of the reflective color liquid crystal device in FIG. The configuration of the ninth embodiment is the same as that of the seventh embodiment shown in FIG.
It has a color filter composed of colors. The horizontal axis of FIG. 12 is the light wavelength, the vertical axis is the transmittance, 1201 is the spectrum of the red filter, 1202 is the spectrum of the green filter,
Reference numeral 1203 indicates the spectrum of the blue filter. The minimum transmittance of the red color filter for light having a wavelength in the range of 450 nm to 660 nm is smaller than the minimum transmittance of the blue and green color filters for light having a wavelength in the range of 450 nm to 660 nm. Here, only the green filter has a wavelength range of 450 nm to 660 nm,
It has a transmittance of 50% or more. In addition, 4 of the red filter
The minimum transmittance for light having a wavelength in the range of 50 nm to 660 nm is distinctly smaller than that of the blue and green filters. By using such a red filter, it is possible to vividly display red which appeals to human eyes most. To compensate for the darkening of red, the spectrum 1203 of the blue filter was set close to cyan.
For this reason, bright white with little coloring was able to be displayed.

The reflection type color liquid crystal device prepared as described above has a reflectance of 26% in white display, a contrast ratio of 1:13, is capable of full color display, and has a red display color of x.
= 0.41, y = 0.30, green display color is x = 0.31,
y = 0.36, blue display color x = 0.26, y = 0.28
Met. This is about 7 of the conventional reflective monochrome liquid crystal device.
The brightness is relatively high and the contrast ratio is the same. Since the red color is particularly emphasized, the color reproducibility is not sufficient. Therefore, it is more suitable for displaying on a portable information device or the like than displaying video images.

(Embodiment 10) FIG. 10 is a diagram showing a main part of the structure of a reflective type color liquid crystal device according to Embodiment 10 of the present invention. The configuration will be described. 1001 is an upper polarizing plate, 1
002 is an element substrate, 1003 is a liquid crystal, 1004 is a counter substrate, 1005 is a lower polarizing plate, 1006 is a scattering reflector, and a counter electrode (scanning line) 101 is provided on the counter substrate 1004.
1 and a color filter 1010, and an element substrate 1002
A signal line 1007, an MIM element 1008, and a pixel electrode 1009 are provided thereon. The color filter 1010 is of a pigment dispersion type, and has three colors of red (indicated by “R” in the figure), green (indicated by “G” in the figure), and blue (indicated by “B” in the figure). Made up of

FIG. 13 is a diagram showing the spectral characteristics of the color filter 1010. The horizontal axis of FIG. 13 is the wavelength of light, the vertical axis is the transmittance, 1301 and 1311 are the spectra of the red filter, 1302 and 1312 are the spectra of the green filter,
Reference numerals 1303 and 1313 denote the spectra of the blue filter. 1301 and 1311, 1302 and I312,
The color filter materials 1303 and 1313 have the same color filter material, but have different thicknesses. The former is 0.8 μm and the latter is 0.2 μm. The average transmittance of the red filter for light in the wavelength range of 450 nm to 660 nm is 28% when the thickness is 0.8 μm, and 0.2 μm
At that time, it was 74%. The average transmittance of the green filter was 33% when the thickness was 0.8 μm, and 75% when the thickness was 0.2 μm. The average transmittance of the blue filter is 30% when the thickness is 0.8 μm, and 74% when the thickness is 0.2 μm.
%Met.

FIG. 14 is a diagram plotting the average transmittance when the thickness of the color filter is variously changed.
In the figure, 1401 is a blue filter, 1402 is a green filter, 1
Reference numeral 403 denotes the case of a red filter. In any case, as the color filter becomes thinner, the average transmittance tends to increase. The thickness of a normal pigment dispersion type color filter used in the transmission type is about 0.8 μm, but when such a color filter is used, it can be used under direct sunlight outdoors or special lighting such as a spotlight. Unless performed, only a dark display that could not be distinguished was obtained. 0.23μm thickness
Below, that is, the average transmittance of any color filter is 70
%, A brightness that can be used comfortably in a relatively bright room with an illuminance of about 1000 lux, for example, in an environment such as an office desk illuminated by a fluorescent lamp stand was obtained. When the thickness is 0.18 μm or less, that is, when the average transmittance of each color filter is 75% or more, the illuminance 200
Luminance sufficient for use under ordinary indoor lighting light of about lux was obtained. When the thickness was 0.8 μm or more, that is, when the average transmittance of each color filter was 90% or less, it was possible to display to the extent that the color could be clearly recognized. As described above, the pigment-dispersed type color filter has a thickness of 0.23 μm or less, preferably 0.18 μm or less, and more preferably 0.08 μm or more.

(Embodiment 11) FIG. 15 is a diagram showing a main part of the structure of a reflective type color liquid crystal device according to Embodiment 11 of the present invention. In this embodiment, a color filter is provided only in a part of the light modulatable area in each dot. First, the configuration will be described. 1501 is an upper polarizer, 1502 is an element substrate, 1503 is a liquid crystal, 1504 is a counter substrate, 15
Reference numeral 05 denotes a lower polarizing plate, and reference numeral 1506 denotes a scattering reflector. A counter electrode (scanning line) 1511 and a color filter 1510 are provided on a counter substrate 1504, and a signal line 1507, a MIM element 1508, and a pixel are provided on an element substrate 1502. Electrode 1509
Was provided. The area where light modulation is possible in one dot is an area where the recessed ITO on the element substrate and the strip-shaped ITO on the opposing substrate overlap each other, and the outline thereof is indicated by a broken line on the ITO of the opposing substrate. . (Refer to FIG. 20 which shows a similar outline, although it does not partially overlap with the color filter.)

The opposing electrode 1511 and the pixel electrode 1509 were formed of transparent ITO, and the signal line 1507 was formed of metal Ta. The MIM element has a structure in which an insulating film Ta ₂ O ₅ is sandwiched between metal Ta and metal Cr. The liquid crystal 1503 is a 90 degree twisted nematic liquid crystal, and Δn × d of the liquid crystal cell is 1.3.
The Δn of the liquid crystal and the cell gap d were selected so as to be 4 μm. The upper and lower polarizing plates were arranged such that their absorption axes were parallel to the rubbing axis of the adjacent substrate. This is the brightest and less colored TN mode configuration. The color filter 1510 has two complementary colors, red (indicated by “R” in the figure) and cyan (indicated by “C” in the figure).
Although it is made of color, it is provided only in a part of the light modulatable area.

FIG. 16 is a diagram showing the spectral characteristics of the color filter 1510. The horizontal axis of FIG. 16 is the light wavelength, the vertical axis is the transmittance, 1601 is the spectrum of the red filter, 16
02 indicates the spectrum of the cyan filter. 45
The average transmittance obtained by simply averaging the transmittance in the wavelength range of 0 nm to 660 nm was 30% for the red filter and 58% for the cyan filter. However, this is the case where the color filter is provided on the entire surface, and when only a part of the color filter is provided, the average value in the light modulatable region will be referred to as the average transmittance.

FIG. 17 shows the results obtained by changing the ratio of the area in which the color filter is provided in the light modulatable region to various values and calculating the average transmittance at that time. Reference numeral 1701 denotes an average transmittance of a dot provided with a red filter, and 1702 denotes an average transmittance of a dot provided with a cyan filter.

When the color filter area ratio was 100%, that is, when the color filters were provided on the entire surface, the display was so dark as to be indistinguishable unless it was exposed to direct sunlight outdoors or special lighting such as a spotlight. . When the area ratio of the color filters is 45% or less, that is, when the average transmittance of each color filter is 70% or more, the environment of an environment such as an office desk illuminated by a fluorescent lamp stand, for example, a relatively bright room with an illuminance of about 1000 lux. Underneath, a comfortable working brightness was obtained. Color filter area ratio is 35% or less,
That is, when the average transmittance of any of the color filters was 75% or more, a sufficiently usable brightness was obtained even under normal room illumination light having an illuminance of about 200 lux. Further, when the color filter area ratio was 15% or more, that is, when the average transmittance of any of the color filters was 90% or less, display was possible to the extent that red and cyan could be distinguished. When the area ratio of the color filters was 25% or more, that is, when the average transmittance of all the color filters was 90% or less, the display could be performed to the extent that the colors could be clearly recognized. When any of the color filters was used, a high contrast ratio of 1:15 or more was obtained.

The color filter used in the eleventh embodiment has the same spectral characteristics and the same brightness as the color filter used in the normal transmission type, except that cyan is used. It is desirable that such a color filter be provided in an area of 45% or less, preferably 35% or less, and 15% or more, preferably 25% or more of the light modulatable region.

In the first embodiment, the MIM element is used as the active element. However, this is somewhat advantageous in increasing the aperture ratio. The effect remains unchanged.

(Embodiment 12) Embodiment 12 is also a reflection type color liquid crystal device in which a color filter is provided only in a part of a light modulatable area in each dot. The structure of the reflection type color liquid crystal device in this embodiment is the same as that of the reflection type color liquid crystal device of the embodiment 11 shown in FIG. 15, but the embodiment 12 is different in the characteristics of the color filter.

FIG. 18 is a diagram showing the spectral characteristics of the color filters used in the twelfth embodiment. In FIG. 18, the horizontal axis is the light wavelength, and the vertical axis is the transmittance. 1801 shows the spectrum of the red filter, and 1802 shows the spectrum of the cyan filter. The average transmittance of the red filter was 41%, and the average transmittance of the cyan filter was 62%. This level of brightness is the maximum for a color filter that can be manufactured by conventional processes without problems such as pigment dispersibility.

FIG. 19 shows the results obtained by changing the ratio of the area in which the color filter is provided in the light modulatable region and changing the average transmittance at that time. Reference numeral 1901 denotes an average transmittance of a dot provided with a red filter, and reference numeral 1902 denotes an average transmittance of a dot provided with a cyan filter.

When the color filter area ratio was 100%, that is, when the color filters were provided on the entire surface, the display was dark and hard to see unless it was exposed to direct sunlight outdoors or special lighting such as a spotlight. . When the color filter area ratio is 50% or less, that is, when the average transmittance of each color filter is 70% or more, a relatively bright room having an illuminance of about 1000 lux, for example, an environment such as an office desk illuminated by a fluorescent lamp stand is used. Underneath, comfortable brightness was obtained. When the color filter area ratio was 40% or less, that is, when the average transmittance of each color filter was 75% or more, sufficient brightness was obtained even under normal room illumination light with an illuminance of about 200 lux. When the area ratio of the color filters was 15% or more, that is, when the average transmittance of any of the color filters was 90% or less, it was possible to display such that red and cyan could be distinguished. 25% color filter area ratio
That is, the average transmittance of each color filter is 90
%, The color could be displayed to the extent that the color was clearly recognizable. When any of the color filters was used, a high contrast ratio of 1:15 or more was obtained.

The color filter used in Example 12 is much brighter than a color filter used in a normal transmission type. It is desirable that such a color filter be provided in an area of 50% or less, preferably 40% or less, and 15% or more, preferably 25% or more of the light modulatable region.

(Embodiment 13) FIG. 20 is a diagram showing a main part of a diagram structure of a reflection type color liquid crystal device in Embodiment 13 of the present invention. Also in this embodiment, the color filter is provided only in a part of the light modulatable area in each dot.
The configuration will be described. 2001 is an upper polarizer, 2002 is an element substrate, 2003 is a liquid crystal, 2004 is a counter substrate, 200
Reference numeral 5 denotes a lower polarizer, 2006 denotes a scattering reflector, and a counter electrode (scanning line) 2011 and a color filter 2010 are provided on a counter substrate 2004. A signal line 2007, a MIM element 2008, and a pixel are provided on an element substrate 2002. An electrode 2009 was provided. The light modulatable region in one dot is a region where the concave ITO on the element substrate and the strip-shaped ITO on the opposing substrate overlap each other, and the outline thereof is indicated by a broken line on the ITO of the opposing substrate.

The color filter 2010 is composed of two colors of red (indicated by “R” in the figure) and cyan (indicated by “C” in the figure) which are complementary to each other. It was provided almost in the center. It is desirable to arrange such that there is no other color filter around each color filter. With this arrangement, it is possible to perform display with less color mixture. Because, usually, at least a distance corresponding to the thickness of the counter substrate exists between the color filter layer and the reflector, light incident through the red filter exits through the cyan filter, or The reverse causes color mixing, but the above arrangement reduces the probability.

(Embodiment 14) FIG. 21 is a diagram showing a main part of the structure of a reflective type color liquid crystal device according to Embodiment 14 of the present invention. Also in this embodiment, the color filter is provided only in a part of the light modulatable area in each dot. The configuration will be described. 2101 is an upper polarizing plate, 2102 is an element substrate, 2103 is a liquid crystal, 2104 is a counter substrate, 2105
Denotes a lower polarizer, 2106 denotes a scattering reflector, and a counter electrode (scanning line) 2112 and a color filter 2111 are provided on a counter substrate 2104, and a signal line 2107, an MIM element 2108, and a pixel electrode are provided on an element substrate 2102. 2109 were provided.

The color filter 2111 is composed of two colors of red (indicated by “R” in the figure) and cyan (indicated by “C” in the figure) which are complementary to each other. It was divided into five areas and arranged in a checkered pattern. If a color filter is provided only in a part of the dot, a portion without the color filter is likely to be conspicuous white, but when divided and arranged in such a small area, there is an advantage that color mixture is good. Of course, the number of divisions may be two, but dividing into three or more is more effective.

A black mask 2 is provided at a position covering the scanning line.
110 (indicated by "BK" in the figure). This black mask is formed when the opposing substrate 2104 is located on the upper side and the element substrate 2102 is located on the lower side in FIG.
In particular, it has an effect of preventing reflection. Further, instead of using a black pigment, red, cyan, or a combination thereof may be used instead.

(Embodiment 15) In the reflection type color liquid crystal device of Embodiment 15, a color filter is provided only in a part of a light modulatable area in each dot. The structure of the reflective color liquid crystal device in this embodiment is the same as that of the reflective color liquid crystal device of Embodiment 12 shown in FIG. 15, the reflective color liquid crystal device of Embodiment 13 shown in FIG. 20, and the structure shown in FIG. This is the same as the reflective color liquid crystal device described in Example 14.

The feature is that a color filter is provided at a position between an electrode and a liquid crystal. Generally, a color filter is often provided at a position between an electrode and a substrate in order to efficiently apply a voltage to a liquid crystal. However, by arranging as in the present embodiment, two new effects were obtained. One is to increase the viewing angle, and the other is to improve the color purity in the halftone.

FIG. 22 is a diagram showing the voltage reflectance characteristics of the reflective color liquid crystal device according to the fifteenth embodiment of the present invention.
The horizontal axis is the voltage effectively applied to the liquid crystal, and the vertical axis is the reflectivity normalized to 100% when no voltage is applied. Reference numeral 2201 denotes a characteristic of a region in which a color filter is not provided in a light modulatable region, and reference numeral 2202 denotes a characteristic of a region in which a color filter is provided. Due to the voltage drop due to the capacitance division, 2202 has a sharper voltage reflectance characteristic than 2201. In other words, a voltage is less likely to be applied to the liquid crystal in a region where the color filter is provided than in a region where the color filter is not provided. As described above, since two regions having different voltage application levels exist in one pixel, the effects disclosed in Japanese Patent Application Laid-Open Nos. 2-12 and 4-348323 (generally, "halftone method") are disclosed. ) Improves the viewing angle characteristics. Further, in the halftone display state, the area where the color filter is provided always has a higher reflectance, so that there is also an effect that the color is displayed darker.

(Embodiment 16) FIG. 23 is a view showing a structure of a color filter substrate of a reflection type color liquid crystal device according to Embodiment 16 of the present invention. In this embodiment, the color filter is provided only in a part of the light modulatable area in each dot. In the light modulatable area, the area where the color filter is not provided and the light modulatable area are not provided. In the region, a layer transparent in the visible light region was formed with substantially the same thickness as the color filter. (A) is a front view and (b) is a cross-sectional view. First, the configuration will be described. A rectangular area 2304 surrounded by a broken line in FIG. Reference numeral 2309 denotes a glass substrate, 2301 a red filter, 2303 a green filter, 2302 a blue filter, 2305 a gap between dots, a hatched area 2308 an acrylic, 2307 a protective film, and 2306 an ITO transparent electrode.

FIG. 25 shows the spectral characteristics of the color filters used here. The horizontal axis in FIG. 25 is the wavelength of light, the vertical axis is the transmittance, 2501 is the spectrum of the blue filter, 2502
Indicates the spectrum of the green filter, and 2503 indicates the spectrum of the red filter. However, this is the characteristic when the color filter formation area is 100%. A color filter having such spectral characteristics is formed by one dot 2304 in FIG.
And was formed at an area ratio of 50%. As a result, spectral characteristics as shown in FIG. 26 were obtained on average within one dot. In FIG. 26, the horizontal axis represents the wavelength of light, and the vertical axis represents the transmittance.
Reference numeral 601 denotes a blue filter spectrum, 2602 denotes a green filter spectrum, and 2603 denotes a red filter spectrum.

Further, acrylic 2308 was formed in the portion where the color filter was not formed in FIG. 23 with the same thickness as the color filter. The color filters 2301 and 230 at this time
The thickness of each of 2, 2303 and acrylic 2308 is about 0.2 μm. Further, an acrylic transparent layer 2308 was formed also in a gap 2305 between dots without forming a light-shielding film (black stripe) formed between dots and the like used in a normal transmission type color liquid crystal device. Further, a protective film 2307 and an ITO electrode 230 are sequentially formed on the color filter.
6. An alignment film (not shown) for aligning the liquid crystal was formed and superposed on an MIM (metal-insulating film-metal) active matrix substrate to form a liquid crystal device. At this time, the TN mode was used as the liquid crystal mode.

FIG. 24 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to the sixteenth embodiment. 2402 is an element substrate, 2403 is a counter substrate, 2406 is an MIM element,
2407 is a display electrode of one dot, 2408 is a scanning line, 2
401 is an upper polarizer, 2409 is a partially formed red color filter, 2410 is a partially formed green color filter, 2411 is a partially formed blue color filter,
Reference numeral 2412 denotes an acryl, 2413 a signal electrode, 2404 a lower polarizing plate, and 2405 an aluminum reflector.

The color filter is provided with an area ratio of 50 per dot.
% In a reflection type color liquid crystal device using a substrate formed only with the color filter, the alignment of the liquid crystal is disturbed by the step between the color filter forming portion and the non-forming portion, and the contrast is 1: 8. A reflection type color liquid crystal device using a substrate formed in the unformed portion with the same thickness as the color filter can display a high quality image without disturbance of liquid crystal alignment. The contrast at this time was 1:20. FIG. 27 shows a configuration of a color filter in the case where an acrylic transparent layer is not formed in a portion where no color filter is formed. (A) is a front view and (b) is a cross-sectional view. Reference numeral 2707 denotes a glass substrate, and 2701 denotes a partially formed red filter.
3 is a partially formed green filter, 2702 is a partially formed blue filter, 2706 is a protective film, and 2704 is 1
A dot 2705 is a gap between pixels. As is clear from the cross-sectional view of (b), the surface of the color filter has irregularities, and in such a surface state, the liquid crystal alignment is disturbed.

In this embodiment, the color filter substrate of the present invention and the MIM substrate are combined.
A (thin film diode) substrate may be used. In this embodiment, the active matrix reflective color liquid crystal device has been described. However, the present invention can be applied to a simple matrix reflective color liquid crystal device. The present invention is more effective when the unevenness of the substrate surface greatly affects the liquid crystal alignment as in the STN mode. In the present embodiment, the “mosaic arrangement” is adopted for the color filter arrangement. 321
, A "triangle arrangement" and a "stripe arrangement" may be used.

(Embodiment 17) In the embodiment 17 as well, the color filter is provided only in a part of the light modulatable area in each dot, and the color filter is not provided in the light modulatable area. In a region and a region where light cannot be modulated, a layer transparent in a visible light region was formed with substantially the same thickness as the color filter.

FIG. 28 is a diagram showing a structure of a color filter substrate of a reflective type color liquid crystal device according to Embodiment 17 of the present invention. (A) is a front view and (b) is a cross-sectional view. First, the configuration will be described. A rectangular area 2804 surrounded by a broken line in FIG. 2808 is a glass substrate, 2807 is an ITO electrode, 2801 is a red color filter, 2803 is a green color filter, 2802 is a blue color filter, and a hatched area 2806 is acrylic.

FIG. 29 shows the spectral characteristics of the color filters used here. The horizontal axis of FIG. 29 is the wavelength of light, the vertical axis is the transmittance, 2901 is the spectrum of the blue filter, 2902
Indicates the spectrum of the green filter, and 2903 indicates the spectrum of the red filter. However, this is the characteristic when the color filter formation area is 100%. A color filter exhibiting such spectral characteristics was formed at an area ratio of 30% within one dot in FIG. As a result, spectral characteristics as shown in FIG. 26 were obtained on average within one dot.

Further, acrylic 2807 was formed in a portion where no color filter was formed in FIG. 28 to have the same thickness as the color filter. At this time, the thickness of the color filter and the acrylic is about 0.8 μm. The light-shielding film (black stripe) formed between the dots and the like normally used in a transmission type color liquid crystal device is not formed, and the acrylic is also formed between the dots. A 2807 transparent layer was formed. Further, an alignment film for aligning the liquid crystal was formed, and was superposed on the TFT substrate, thereby forming a liquid crystal device. At this time, a TN mode was adopted as a liquid crystal mode, a polarizing plate was attached to the outside of the glass substrate, and a silver reflector was disposed on the side opposite to the observation surface.

The area ratio of the color filter within one dot is 30.
% In a reflection type color liquid crystal device using a substrate formed only in%, the alignment of the liquid crystal was disturbed by a step between a portion where a color filter was formed and a portion where no color filter was formed, and contrast was 1: 5. A reflection type color liquid crystal device using a substrate formed in the unformed portion with the same thickness as the color filter was able to perform high-quality display without disturbance of liquid crystal alignment. The contrast at this time was 1:18.

In this embodiment, the color filter substrate of the present invention and the TFT substrate are combined.
A substrate may be used. In this embodiment, the active matrix reflective color liquid crystal device has been described. However, the present invention can be applied to a simple matrix reflective color liquid crystal device. ST
The present invention is more effective when the unevenness of the substrate surface greatly affects the liquid crystal alignment as in the N mode.

In the sixteenth and seventeenth embodiments, the three primary colors of red, green and blue are used for the color filters.
Two color filters having complementary colors such as 1 and green 3102 or yellow and blue can also be used.

(Embodiment 18) Embodiments 16 and 17
In the embodiment, the color filter is partially formed substantially at the center of one dot. However, the color filter may be formed in an arrangement as shown in FIGS. (A) is an area 320 where the upper half or the lower half of one dot 3201 forms a color filter.
2 and the other half is an area 3203 where no color filter is formed. (B) is an area 3202 in which the right half or the left half of one dot 3201 forms a color filter.
Are formed, and the other half is a region 3203 where no color filter is formed. FIG. 32 (c)
As shown in (d), the inside of one dot 3201 is divided into two or more, and a part is formed in a region 3202 where a color filter is formed.
The remainder may be an area 3203 where no color filter is formed. Even with the use of color filters of various patterns, a reflective color liquid crystal device with high image quality could be realized.

(Embodiment 19) Table 1 shows the change in characteristics when the step between the color filter and the transparent layer in Embodiment 16 was changed. As the step becomes smaller, both image quality and contrast are improved. If the step is 0.5 μm or less, a contrast of 1:10 or more can be obtained, and if it is 0.1 μm or less, a contrast of 1:15 or more can be obtained.

[Table 1]

(Embodiment 20) Embodiments 16 and 17
Although acrylic was used for the transparent layer that fills the step between the color filter formed portion and the unformed portion, a reflective color liquid crystal device with high image quality could be realized even when polyimide was used. Similarly, a high-quality reflective color liquid crystal device could be realized even when polyvinyl alcohol was used for the transparent layer. Table 2 summarizes the results. Both the image quality and the contrast are improved as compared with the case where there is no transparent layer.

[Table 2]

In the examples 16 and 17, a common aluminum reflector or silver reflector was used as the reflector. G. FIG. A holographic reflector (SID'95 DIGEST, PP. 176-17) presented by Chen et al.
9) can also be used.

(Embodiment 21) FIG. 33 is a diagram showing a main part of the structure of a reflective type color liquid crystal device according to Embodiment 21 of the present invention. In this embodiment, a color filter is provided only for dots that are three-fourths or less of the total number of dots.
The configuration will be described. 3301 is an upper polarizing plate, 3302 is an element substrate, 3303 is a liquid crystal, 3304 is a counter substrate, 330
Reference numeral 5 denotes a lower polarizing plate, reference numeral 3306 denotes a scattering reflector, and a counter electrode (scanning line) 3311 and a color filter 3310 are provided on a counter substrate 3304. A signal line 3307, a MIM element 3308, and a pixel An electrode 3309 was provided.

The color filter 3310 is composed of two colors of red (indicated by “R” in the figure) and cyan (indicated by “C” in the figure) which are complementary to each other. No color filter was provided. The color filters used here are the same as in Example 1, and the spectral characteristics are shown in FIG.

FIG. 34 shows the arrangement of the color filters and FIG.
FIG. 3 is a diagram viewed from above. In the figure, “R” indicates a dot provided with a red filter, “C” indicates a dot provided with a cyan filter, and “W” indicates a dot without a color filter. A red filter was provided for one-third of the dots, a cyan filter was provided for one-third of the dots, and no color filter was provided for the remaining one-third of the dots. 34 (a), (b), (c) and (d) in FIG.
The distribution of on dots and off dots when red, cyan, and black are displayed is shown. The hatched dots are on dots, that is, a dark state, and the unhatched dots are off dots, that is, a bright state. When the display is performed in this manner, the color display is performed by 2/3 of the total dots,
Brighter than normal display is possible. Also in the case of displaying halftones in color display, there is a merit that a vivid color can always be displayed by adjusting the brightness mainly with dots without a color filter. For example, in the case of displaying darker red, all dots with a red filter may be turned off, dots with a cyan filter may be turned on, and dots without a color filter may be turned on half.

FIG. 35 shows another color filter arrangement.
A red filter was provided for １ ／ of the total dots, a cyan filter was provided for １ ／ of the dots, and a color filter was not provided for the remaining ド ッ ト of the dots. FIG. 35 (a)
(B), (c), and (d) show the distribution of on dots and off dots when displaying white, red, cyan, and black, respectively. When the display is performed in this manner, since a color display is performed with ３ of the entire dots, a display brighter than the color filter arrangement of FIG. 35 can be performed.

As another example, FIG. 36 shows an arrangement in which three red, green and blue color filters are used. In the figure, "R" indicates a dot provided with a red filter, "G" indicates a dot provided with a green filter, "B" indicates a dot provided with a blue filter, and "W" indicates a dot without a color filter. I have. A red filter is used for 1/6 of the dots,
No. 1 dot was provided with a green filter, 1/6 dot was provided with a blue filter, and the remaining 1/2 dot was not provided with a color filter. 36 (a), (b) and (c) of FIG.
(D) shows the distribution of on dots and off dots when displaying white, red, green, and blue, respectively. When display is performed in this manner, bright display is possible because color display is performed with 4/6 dots of the whole.

Further, a red filter is provided for 1/4 of the entire dot, a green filter is provided for 1/4 of the dot, a blue filter is provided for 1/4 of the dot, and a color filter is provided for the remaining 1/4 of the dot. A configuration without a filter is also possible. When the display is performed in this manner, a bright display is possible because color display is performed with half of the total dots.

(Embodiment 22) FIGS. 37A and 37B are diagrams schematically showing the structure of a reflective type color liquid crystal device according to Embodiment 22 of the present invention. FIG. 37A is a front view, and FIG. In this embodiment, a color filter is provided over the entire effective display area. The configuration will be described. 3701 is a frame case,
3702 is an upper polarizing plate, 3703 is an upper substrate, 3704
Is a color filter, 3705 is a lower substrate, and 3706 is a polarizing plate with a reflector. Since the drawings are complicated, transparent electrodes, nonlinear elements, signal lines, alignment films, and the like are omitted. Reference numeral 3711 denotes a drive display area, 3712 denotes an effective display area, and 3713 denotes an area provided with a color filter. (B) is a horizontal cross-sectional view, but the vertical cross-sectional view is the same as (b). Note that the terms “drive display area” and “effective display area” are defined by the Japan Electronic Machinery Manufacturers Association standard (EI).
AJ) ED-2511A defines "a region having a display function in a liquid crystal display device" and "a drive display region and a subsequent region effective as a screen". That is, the drive display area is an area where a voltage can be applied to the liquid crystal, and the effective display area is all the liquid crystal panel areas that are not hidden by the frame case.

The feature of the twenty-second embodiment is that an area 3713 provided with a color filter is the same as or wider than the effective display area 3712. With this configuration,
The reflective color liquid crystal device of Example 22 has the advantage that the display looks bright. Normally, in a transmissive color display,
A color filter is provided only in the drive display area, and a black mask of metal or resin is provided in an area outside the color filter. However, in a reflective color display, a metal black mask cannot be used because it is glaring. Further, the cost of the resin black mask increases because the original color filter is not provided with the black mask. However, if nothing is provided outside the driving display area, the outside becomes bright and the driving display area looks relatively dark. Therefore, it is effective to provide a color filter similar to that inside the drive display area, preferably in the same pattern, outside the drive display area in order to make the display look bright.

(Embodiment 23) In a transmission type color liquid crystal device, a black mask is generally provided outside a dot. However, when a black mask is provided in a reflection type color liquid crystal device, high contrast is obtained, but display becomes extremely dark. . In particular, in a liquid crystal mode in which parallax is inevitable, such as a TN mode or an STN mode, there are two cases in which light enters and exits.
Since the light is absorbed by the black mask, the brightness is proportional to the square of the aperture ratio. Therefore, a black mask cannot be provided in the reflection type color liquid crystal device. Conversely, if no light absorber is provided outside the dots, the contrast is significantly reduced, which is not preferable. Therefore, in Embodiment 23 of the present invention, no black mask is provided outside the dots,
Instead, a color filter having absorption equal to or smaller than the area in the dot is provided.

FIG. 38 is a diagram showing a color filter arrangement of a reflective color liquid crystal device according to Embodiment 23 of the present invention. As described above, in this embodiment, the black mask was not provided in the area outside each dot, and instead, a color filter having absorption equal to or smaller than the area in the dot was provided. Although the basic configuration and the spectral characteristics of the color filters are the same as those in FIGS. 6 and 3 of the fifth embodiment, the arrangement of the color filters in the area outside the dots is devised. In FIG. 38, the “horizontally convex” region 3801 indicates that the counter electrode and the pixel electrode overlap each other.
This is a region where an electric field is applied to the liquid crystal, and corresponds to the above-mentioned dot. An area 3802 hatched diagonally from upper right to lower left is a cyan filter, and an area 3803 hatched on a cross is a red filter.

In FIG. 38 (a), the red filter and the cyan filter are arranged so as to be in direct contact with each other outside the dots.
In (b), filters are provided outside the dots, but are arranged apart from each other. In (c), a red filter is arranged outside the dot. All have absorptions in the region outside the dots that are equal to or smaller than those in the dots but are not zero, so that a bright and high-contrast display can be obtained. Each characteristic is as follows: (a) the reflectance at the time of white display is 30%.
The contrast ratio was 1:15, the reflectance ratio was 33% in (b), and the contrast ratio was 1:13, and the contrast ratio was 29% and 1:16 in (c).

(Embodiment 24) FIG. 39 is a diagram showing a color filter arrangement of a reflection type color liquid crystal device in Embodiment 24 of the present invention. Also in this embodiment, the black mask is not provided in the area outside each dot, and a color filter having absorption equal to or smaller than the area in the dot is provided instead. Although the basic configuration and the spectral characteristics of the color filters are the same as those in FIGS. 8 and 12 of the ninth embodiment, the arrangement of the color filters in the area outside the dots is devised. In FIG. 39, the “horizontally convex” region 3901 is a region where the counter electrode and the pixel electrode overlap and an electric field is applied to the liquid crystal, and corresponds to the dot of Example 23. An area 3902 hatched obliquely from upper left to lower right is a blue filter, an area 3903 hatched obliquely from upper right to lower left is a green filter, and an area 3904 hatched to a cross.
Is a red filter.

In FIG. 39A, filters of three colors are provided outside the dots, but are arranged apart from each other. The separation distance was set in anticipation of the maximum misalignment in producing the color filter. That is, FIG. 39B shows the arrangement of the color filters in the case where the assumed maximum misalignment occurs. Even in this case, the color filters of different colors are prevented from overlapping each other. The overlapping of the color filters is almost synonymous with the presence of the black mask, so that this must be avoided as much as possible. By arranging the color filters as described above, a bright and high-contrast reflective color display was achieved.

(Embodiment 25) FIG. 40 is a diagram showing a main part of a reflective color liquid crystal device according to Embodiment 25 of the present invention. Also in this example, the black mask was not provided in the region outside each dot, and instead, a color filter having absorption equal to or smaller than the region in the dot was provided. First, the configuration will be described. 4001 is an upper polarizing plate, 4002 is a counter substrate, 4003 is a liquid crystal, 4004 is an element substrate, 40
05 is a lower polarizing plate, 4006 is a scattering reflector, and a color filter 4007 and a counter electrode (scanning line) 4008 are provided on a counter substrate 4002, and a signal line 4009, a pixel electrode 4010, MIM element 401
1 was provided. This color filter has a stripe arrangement commonly used in data displays such as PCs. The spectral characteristics of the color filters are the same as in FIG. 12 of the ninth embodiment.

FIG. 41 is a diagram showing a color filter arrangement of a reflection type color liquid crystal device according to Embodiment 25 of the present invention. In FIG. 41, the “horizontally convex” area 4101 is an area where the counter electrode and the pixel electrode overlap and an electric field is applied to the liquid crystal, and corresponds to the dot of Example 23. A region 4102 hatched diagonally from upper left to lower right is a blue filter, a region 4103 hatched diagonally from upper right to lower left is a green filter, and a region 4104 hatched to a cross is a red filter. is there.

In FIG. 41A, filters of three colors are also provided outside the dots, but they are arranged continuously vertically and separated from each other on the left and right. The separation distance was set in anticipation of the maximum misalignment in producing the color filter.
That is, FIG. 41B shows the arrangement of the color filters in the case where the assumed maximum misalignment occurs. Even in this case, the color filters of different colors are prevented from overlapping each other. By arranging the color filters as described above, a bright and high-contrast reflective color display was achieved.

(Embodiment 26) FIG. 42 is a sectional view showing a main part of the structure of a reflective color liquid crystal device according to Embodiment 26 of the present invention. In this embodiment, a color filter is provided on the outer surface of the substrate located on the side of the reflection plate among the pair of substrates.
The configuration will be described. 4201 is an upper polarizer, 4202 is an element substrate, 4203 is a liquid crystal, 4204 is a counter substrate, 420
Reference numeral 5 denotes a lower polarizing plate, 4206 denotes a scattering reflector, and a signal line 4207 and a pixel electrode 4208 are provided on the element substrate 4202, and a counter electrode (scanning line) 42 is provided on the counter substrate 4204.
09 was provided. Although not shown in this sectional view, the signal line and the pixel electrode are connected via an MIM element. A red filter 4210, a green filter 4211, and a blue filter 4212 are provided on the surface of the counter substrate 4204 on the side of the reflector.

The spectral characteristics of the color filters are as shown in FIG. 12 if they are provided on the entire surface of the dots, and FIG. 16 and FIG.
The characteristics shown in FIG.

By providing a color filter outside the substrate in this way, an inexpensive color filter can be used. This color filter may be separately provided on a film or the like, and may be laminated later. In particular, by providing color filters only for some of the dots,
There is an advantage that the assembly margin is increased and the viewing angle is increased.

(Embodiment 27) In Embodiment 27, a non-linear element is provided corresponding to each dot on the inner surface of the substrate located on the reflector side of the pair of substrates. The structure of the reflective color liquid crystal device in this embodiment is the same as that of FIG. 1 of the first embodiment, FIG. 6 of the sixth embodiment, and FIG. 8 of the seventh embodiment. Its features are on the substrates 104, 604, 804 located on the reflector side,
That is, the MIM elements 111, 611, and 811 are provided. By arranging in this way, the opposite groove formation,
That is, unnecessary surface reflection was reduced and high contrast was obtained as compared with the case where MIM elements were provided on the substrates 102, 602, and 802. There are three reasons. One is signal line 1
09, 609, and 809 and the reflection by the MIM element is partially absorbed by the color filters 107, 607, and 807. The second is a structure in which the signal line itself is formed by superposing metal Cr on metal Ta. That is, the reflectance of Cr is smaller than that of Cr. Third, the reflected light is the liquid crystal layer 103,
By passing through 603 and 803, absorption by birefringence interference occurs.

(Embodiment 28) In Embodiment 28, a non-linear element is provided corresponding to each dot on the inner surface of one of a pair of substrates, and is connected in a direction parallel to the short side of the dot. . The overall structure of the reflection type color liquid crystal device in this embodiment is the same as, for example, FIG. The feature lies in the wiring method of the MIM element.

FIG. 43 is a diagram showing a wiring method of the MIM elements of the reflection type color liquid crystal device in the embodiment 28. 4
301 is a signal line, 4302 is a MIM element, and 4303 is a pixel electrode. Since the pixel electrodes correspond to the red, green, and blue color filters of the opposite substrate, the correspondence is indicated by “R”, “G”, and “B” on the pixel electrodes.

Each dot in FIG. 43 has a vertically long shape, and one dot is formed by three dots arranged horizontally. This is a configuration often seen in data displays for personal computers. At this time, the signal lines are wired in parallel with the short sides of the dots, that is, in the horizontal direction. Such wiring has the effect of reducing the number of wirings and increasing the aperture ratio. Here, the aperture ratio is a ratio occupied by a region excluding an opaque portion such as a metal.

This will be compared with the conventional configuration. FIG.
FIG. 9 is a diagram illustrating a wiring method of a (transmissive) color liquid crystal device using a conventional MIM element. 4401 is a signal line, 4402
Denotes an MIM element and 4403 denotes a pixel electrode. The dot pitch is the same as in FIG. 43, and the dots have a vertically long shape, but the signal lines are wired in parallel with the long sides of the dots, that is, in the vertical direction. With this wiring, the number of wirings is three times that of FIG. 43 and the aperture ratio is low. Conventionally, such wiring was performed because, in a horizontally long panel, the distance in the vertical direction was shorter than that in the horizontal panel. This is because the aperture ratio does not change even if wiring is performed.

As described above, when the aperture ratio is high, the display becomes bright. The effect of the aperture ratio on the brightness, particularly the remarkable effect in the reflection type configuration having parallax, has already been described in detail in Examples 23 to 25.

(Embodiment 29) In embodiment 29, the driving area ratio is 60% or more and 85% or less. FIG. 45 shows the characteristics of the reflective color liquid crystal device in this embodiment. The same configuration as that of the second embodiment is adopted, and the driving area ratio is set to 50% to 100%.
The relationship between the drive area ratio and the contrast and the relationship between the drive area ratio and the reflectance when the ratio is changed to% are shown. Here, the driving area ratio is defined as a ratio of a region where liquid crystal is driven in a region excluding an opaque portion such as a metal wiring or an MIM element in a pixel. The horizontal axis represents the driving area ratio, and the vertical axis represents the contrast and the reflectance. 4501 is the contrast of the present embodiment, 4502 is the contrast of the comparative example, 4503 is the reflectance of the present embodiment for cyan display, and 4504 is the comparative example. This is the reflectance at the time of cyan display.

If the driving area ratio is 60% or more, a good contrast of 1: 5 or more can be obtained. If the driving area ratio is 85% or less, good brightness of 23% or more in cyan display can be obtained.

(Embodiment 30) In a reflective type color liquid crystal device, the characteristics of the scattering reflector are brightness, contrast,
It greatly affects viewing angle characteristics. There are various types of scattering reflectors, from those with low scattering properties like mirror surfaces to those with strong scattering properties like paper, and are selected according to the surrounding environment. It is desirable to use a material having a low scattering property in consideration of the contrast and the contrast.

FIGS. 46 and 47 show the characteristics of the reflection plate of the reflection type color liquid crystal device in the embodiment 30 of the invention. The reflector has a scattering characteristic such that when a light beam enters the reflector, 80% or more of the light is reflected in a 30-degree cone centered on the specular reflection direction.

In FIG. 46, reference numeral 4604 denotes a scattering reflector,
Reference numeral 4601 denotes light incident on the surface of the scattering reflector at an angle of 45 °, 4602 denotes specular reflection light, and 4603 denotes a 30-degree cone centered on specular reflection. In FIG. 47, the horizontal axis represents the light receiving angle of the reflected light, and the vertical axis represents the relative reflection intensity. The reflector of Example 30 has a characteristic that about 95% of the incident light is reflected into the 30 ° cone shown in FIG. If this ratio is less than 80%, a contrast ratio of 1:10 or more cannot be obtained under a normal indoor environment.

FIG. 48 shows the result of computer simulation for reference. The horizontal axis of the figure is 30 shown in FIG.
The percentage of light reflected into the degree cone, the vertical axis of the figure being the brightness and contrast ratio. As the light source, perfectly scattered white light such as an integrating sphere was assumed, and the light reflected in the normal direction of the substrate was calculated. The brightness is 100% of the brightness of the standard white plate.
%. As is clear from the simulation results, the higher the proportion of the light reflected in the 30-degree cone, that is, the lower the degree of scattering of the reflector, the brighter the display and the higher the contrast. However, it has been experimentally confirmed that a reflecting plate in which light larger than 95% of the incident light is reflected into the 30-degree cone has a remarkably narrow viewing angle characteristic and is not practical.

(Embodiment 31) FIG. 49 is a diagram showing a main part of the structure of a reflective type color liquid crystal device according to Embodiment 31 of the present invention. The reflector is a semi-transmissive reflector, and has a backlight on the back. First, the configuration will be described. 49
01 is an upper polarizing plate, 4902 is a counter substrate, 4903 is a liquid crystal, 4904 is an element substrate, 4905 is a lower polarizing plate, 49
06 is a transflective plate, 4912 is a backlight,
A color filter 4907 and a counter electrode (scanning line) 4908 are provided over a counter substrate 4902, and a signal line 4909, a pixel electrode 4910, and a MIM element 4908 are provided over an element substrate 4904.
911 were provided. Further, the color filter has the same spectral characteristics as FIG. 3 of the second embodiment.

Since the transflective plate has a reflectance of about 70% of that of a normal scattering reflector, when used in the reflection mode without turning on the backlight, the reflectance at the time of white display is 24%.
%. On the other hand, in the transmission mode in which the backlight is turned on, the transmittance is about 22%, and the surface luminance is 400 c.
Sufficient brightness can be obtained with a monochrome backlight such as d / m ² . Although the characteristics of the color filter as shown in FIG. 3 are originally insufficient for displaying a color by transmission, the use of a semi-transmissive reflector increases the color purity by reflection of ambient light even in a transmission mode. effective.

It is desirable that the transflective plate reflects 80% or more of the incident light in order to obtain a bright display. Inevitably, the display will be dark when used in transparent mode,
Pursuing the brightness in the transmissive mode tends to give unsatisfactory results in both transmissive display and reflective display. It is better to be able to see through mode in barely darkness,
A good display that is easily accepted by the market is obtained.

(Example 32) In Example 32, the liquid crystal was a nematic liquid crystal twisted by approximately 90 degrees, and two polarizing plates were arranged so that the transmission axes thereof were orthogonal to the rubbing directions of the adjacent substrates. The basic structure of the reflection type color liquid crystal device in this embodiment and the spectral characteristics of the color filters are the same as those of the fifth embodiment shown in FIGS. Its features are:
The TN mode cell condition is optimized for a reflective color liquid crystal device.

FIG. 50 is a diagram showing the relationship between the axes of the reflective color liquid crystal device in the embodiment 32. Reference numeral 5021 denotes the left-right direction (longitudinal direction) of the liquid crystal panel, 5001 denotes the transmission axis direction of the upper polarizing plate, 5002 denotes the rubbing direction of the opposing substrate located on the upper side, 5003 denotes the rubbing direction of the element substrate located on the lower side, and 5004 Is the transmission axis direction of the lower polarizing plate. Here, the angle 5011 between the rubbing direction of the opposing substrate and the left and right direction of the liquid crystal panel is 45 °, and the angle 501 between the transmission axis direction of the upper polarizer and the rubbing direction of the opposing substrate is 45 °.
2 was set to 90 °, the twist angle 5013 of the liquid crystal was set to 90 ° to the right, and the angle 5014 between the transmission axis direction of the lower polarizing plate and the rubbing direction of the element substrate was set to 90 °. With this arrangement, the molecules at the center of the liquid crystal layer rise from the observer side (that is, the lower side of the figure) when a voltage is applied, and display with high contrast and low visibility of shadows is possible, in combination with the viewing angle characteristics of the TN liquid crystal. An arrangement in which the transmission axis of the polarizing plate is orthogonal to the rubbing direction of the adjacent substrate (so-called O mode) is more preferable because there is less color change in the viewing angle direction than a parallel arrangement (so-called E mode).

The birefringence Δn of the liquid crystal material is set to 0.18.
9. The Δn × d of the liquid crystal cell was set to 1.34 μm by setting the cell gap to 7.1 μm. This is the brightest and less colored condition when the non-selection voltage is applied.
When n × d <1.30 μm, the display color becomes bluish and Δn
When xd> 1.40 μm, there is a problem that the display becomes dark, which is not preferable.

Example 33 In Example 33, the product Δn × d of the birefringence Δn of the liquid crystal and the thickness d of the liquid crystal layer was 0.34 μm.
And less than 0.52 μm. The basic configuration of the reflection type color liquid crystal device in this embodiment is the same as that of the second embodiment shown in FIG. The feature is that the cell condition of the TN mode is further optimized for the reflection type color liquid crystal device.

FIG. 50 is a diagram showing the relationship between the axes of the reflection type color liquid crystal device in the embodiment 33. Reference numeral 5021 denotes the left-right direction (longitudinal direction) of the liquid crystal panel, 5001 denotes the transmission axis direction of the upper polarizing plate, 5002 denotes the rubbing direction of the opposing substrate located on the upper side, 5003 denotes the rubbing direction of the element substrate located on the lower side, and 5004 Is the transmission axis direction of the lower polarizing plate. Here, the angle 5011 between the rubbing direction of the opposing substrate and the left-right direction of the liquid crystal panel is 45 °, and the angle 5012 between the transmission axis direction of the upper polarizer and the rubbing direction of the opposing substrate is 45 °.
To 90 °, the twist angle 5013 of the liquid crystal to 90 ° to the right,
The angle 5014 between the transmission axis direction of the lower polarizing plate and the rubbing direction of the element substrate was set to 90 °. With this arrangement, the molecules at the center of the liquid crystal layer rise from the observer side (that is, the lower side of the figure) when a voltage is applied, and display with high contrast and low visibility of shadows is possible, in combination with the viewing angle characteristics of the TN liquid crystal. An arrangement in which the transmission axis of the polarizing plate is orthogonal to the rubbing direction of the adjacent substrate (so-called O mode) is more preferable because there is less color change in the viewing angle direction than a parallel arrangement (so-called E mode).

Here, the birefringence Δn of the liquid crystal material is set to 0.08
4, and different panels of Δn × d were produced by changing the cell gap.

FIG. 51 shows the relationship between Δn × d and the reflectance during white display. Reference numeral 5101 denotes the reflectance for each Δn × d in the embodiment, and 5102 denotes the reflectance for each Δnxd in the comparative example. The measurement was performed using an integrating sphere so that light was uniformly incident from all directions. The reflectance is 10 for a standard white plate.
Taken to 0%. From FIG. 51, it can be seen that the display angle becomes darker because Δn × d becomes larger, the viewing angle becomes narrower, and the utilization efficiency of obliquely incident light decreases. Therefore, in order to obtain a bright display, it is preferable to use a so-called first minimum condition in which Δn × d is small. However, the first minimum condition has a drawback that the display is greatly colored. For this reason, the conventional reflection type monochrome liquid crystal device uses a condition where Δn × d is large as in the thirty-second embodiment. However, in the reflection type color liquid crystal device, slight coloring can be corrected by adjusting the color filter. In Embodiment 33, by adjusting the color filter so as to have a high transmittance on the long wavelength side, any Δn × d
However, the display was almost colorless and the coloration was almost unchanged.

The highest reflectance is exhibited when Δn × d is 0.42 μm, and the reflectance corresponding to Δn × d in the vicinity is shown in Table 3 below.

[Table 3]

As described above, by setting Δn × d to be larger than 0.34 μm and smaller than 0.52 μm, a bright display can be obtained.

When Δn × d is smaller than 0.40 μm, a bright display is obtained because the viewing angle is wide, but on the other hand, the brightness in the front direction is low and the image looks dark under a spot light source. Xd is preferably 0.40 μm or more. Further, by setting the thickness to 0.48 μm or less, extremely large coloring can be eliminated.
It is preferably 48 μm or less. Most preferred Δn
Xd is 0.42 μm at which the maximum brightness is obtained.

Embodiment 34 In Embodiment 34 of the present invention,
The liquid crystal was a nematic liquid crystal twisted by 90 degrees or more, and two polarizing plates and at least one retardation film were arranged. FIG. 52 is a diagram illustrating a main part of a reflective color liquid crystal device in Example 34. First, the configuration will be described. 520
1 is an upper polarizing plate, 5202 is a retardation film, 5203
Is the upper substrate, 5204 is the liquid crystal, 5205 is the lower substrate, 5
Reference numeral 206 denotes a lower polarizing plate, and 5207 denotes a scattering reflector. A color filter 5208 and a scanning electrode 5209 are provided on the upper substrate 5203, and a signal electrode 5210 is provided on the lower substrate 5205. The retardation film 5202 is a uniaxially stretched polycarbonate film and exhibits a positive retardation. Further, the color filter has the same spectral characteristics as FIG. 3 of the second embodiment.

FIG. 53 is a diagram showing the relationship between the axes of the reflection type color liquid crystal device in the thirty-fourth embodiment. 5321 is the horizontal direction (longitudinal direction) of the liquid crystal panel, 5301 is the transmission axis direction of the upper polarizing plate, 5302 is the rubbing direction of the upper substrate, 5303 is the rubbing direction of the lower substrate, and 5304 is the transmission axis of the lower polarizing plate. The direction 5305 is the stretching direction of the retardation film. Here, the angle 5311 formed by the rubbing direction of the upper substrate and the left-right direction of the liquid crystal panel is set to 30 °, and the angle 5314 formed by the transmission axis direction of the upper polarizer and the stretching direction of the retardation film is set to 54 °. The angle 5315 between the rubbing direction of the upper substrate and the rubbing direction of the upper substrate is 80 °, the twist angle 5312 of the liquid crystal is 240 ° to the left, and the angle 5313 between the transmission axis direction of the lower polarizer and the rubbing direction of the lower substrate is 43 °. Set. With this arrangement,
Molecules at the center of the liquid crystal layer rise from the observer side (that is, the lower side in the figure) when a voltage is applied, and together with the viewing angle characteristics, a high-contrast display in which shadows are difficult to see becomes possible.

This is a phase difference plate compensation type STN mode proposed in Japanese Patent Publication No. 3-50249, which is characterized in that multiplex driving up to a duty ratio of 1/480 can be performed with a simple matrix. Also, despite the use of the same color filter as in the second embodiment, the signal line and the MI
The aperture ratio is high because the M element is unnecessary, and the reflectivity at the time of white display is 33%, which enables very bright display. Although the contrast ratio was relatively low at 1: 8, the number of retardation films for performing color compensation was increased by one.
By performing the multi-line simultaneous selection drive according to the method disclosed in Japanese Patent Publication No. 30-304, it is possible to display the same color with the same contrast as the case where the MIM element is provided.

Example 35 In Example 34 of the present invention,
The liquid crystal was a nematic liquid crystal twisted by 90 degrees or more, and two polarizing plates and at least one retardation film were arranged. FIG. 55 is a diagram illustrating a main part of the structure of a reflective color liquid crystal device according to Example 35. First, the configuration will be described.
5501 is an upper polarizing plate, 5502 is a phase difference film, 5
Reference numeral 503 denotes an upper substrate, 5504 denotes a liquid crystal, 5505 denotes a lower substrate, 5506 denotes a lower polarizing plate, 5507 denotes a scattering reflector, and a color filter 5508 is provided on the upper substrate 5503.
And a scanning electrode 5509, and a signal electrode 5510 on the lower substrate 5505. The retardation film 5502 is a uniaxially stretched polycarbonate film having a positive 587n.
m. {Product of n and cell gap of liquid crystal}
n × d is 0.85 μm.

FIG. 53 is a diagram showing the relationship between the axes of the reflective color liquid crystal device in the embodiment 35. 5321 is the horizontal direction (longitudinal direction) of the liquid crystal panel, 5301 is the transmission axis direction of the upper polarizing plate, 5302 is the rubbing direction of the upper substrate, 5303 is the rubbing direction of the lower substrate, and 5304 is the transmission axis of the lower polarizing plate. The direction 5305 is the stretching direction of the retardation film. Here, the angle 5311 formed by the rubbing direction of the upper substrate and the left-right direction of the liquid crystal panel is set to 30 °, and the angle 5314 formed by the transmission axis direction of the upper polarizing plate and the stretching direction of the retardation film is set to 38 °. The angle 5315 between the rubbing direction of the upper substrate and the rubbing direction of the upper substrate is 92 °, the twist angle 5312 of the liquid crystal is 240 ° to the left, and the angle 5313 between the transmission axis direction of the lower polarizer and the rubbing direction of the lower substrate is 50 °. Set.

FIG. 54 is a diagram showing the spectral characteristics of the color filters of the reflective type color liquid crystal device in the thirty-fifth embodiment. In FIG. 54, the horizontal axis represents the wavelength of light, and the vertical axis represents the transmittance.
Reference numeral 401 denotes the spectrum of the red filter, 5402 denotes the spectrum of the green filter, and 5403 denotes the spectrum of the blue filter. The color filter characteristics are optimized so that white balance can be obtained from the spectral characteristics 5411 in the off state when the color filter is removed from the liquid crystal device. Here, the green filter and the blue filter have a transmittance of 50% or more in a wavelength range of 450 nm to 660 nm. Also 450nm of red filter
The minimum transmittance for light having a wavelength in the range from to 660 nm is distinctly smaller than that of the blue and green filters. By using such a red filter, it is possible to vividly display red which appeals to human eyes most. Further, the spectrum 5403 of the blue filter was set close to cyan for the purpose of compensating for the increase in red.

This is an STN mode of a phase difference plate compensation type proposed in Japanese Patent Publication No. 3-50249, which is characterized in that multiplex driving up to a duty ratio of 1/480 can be performed with a simple matrix. However, in the conventional phase difference plate compensation type STN mode, even though black-and-white display can be performed, only cyan-like white can be obtained. However, the reflective color liquid crystal device of Example 35 was able to display white much closer to neutral than before by optimizing the color filters. In addition, despite the use of the color filter having similar characteristics to that of the ninth embodiment, the aperture ratio is high because the signal line and the MIM element are unnecessary, and the reflectance in white display is 29%, which is very bright display. It is possible.

(Embodiment 36) In Embodiment 36 of the present invention,
A reflector was provided between a pair of substrates, and only one polarizing plate was arranged. FIG. 56 is a diagram illustrating a main part of a reflective color liquid crystal device in Example 36. First, the configuration will be described. 560
Reference numeral 1 denotes an upper polarizer, 5602 denotes a counter substrate, 5603 denotes a liquid crystal, and 5604 denotes an element substrate. A color filter 5605 and a counter electrode (scanning line) 56 are provided on the counter substrate 5602.
06, and a signal line 5607 on the element substrate 5604,
Pixel electrode 5608 also serving as scattering reflector, MIM element 56
09 was provided. The pixel electrode also serving as the scattering reflection plate was obtained by forming irregularities on the surface of a metal aluminum sputtered film by a mechanical or chemical method. Further, the color filter has the same spectral characteristics as FIG. 3 of the second embodiment.

FIG. 57 is a diagram showing the relationship between the axes of the reflective color liquid crystal device in the embodiment 36. Reference numeral 5721 denotes a left-right direction (longitudinal direction) of the liquid crystal panel, 5701 denotes a transmission axis direction of the upper polarizing plate, 5702 denotes a rubbing direction of the upper substrate, and 5703 denotes a rubbing direction of the lower substrate. Here, the angle 5711 between the rubbing direction of the upper substrate and the left-right direction of the liquid crystal panel is 62 °, the angle 5712 between the transmission axis direction of the upper polarizer and the rubbing direction of the upper substrate is 94 °, and the twist angle 5713 of the liquid crystal is It was set at 56 ° to the right.
With this arrangement, the molecules at the center of the liquid crystal layer rise from the observer side (that is, the lower side in the figure) when a voltage is applied, and high contrast display is possible in combination with the viewing angle characteristics.

This is a nematic liquid crystal mode of a one-polarizer type proposed in Japanese Patent Application Laid-Open No. 3-223715. Since a high-contrast black-and-white display can be performed without using a lower polarizer, it is in contact with the liquid crystal. It is characterized in that a scattering reflector can be provided at a position.

This reflective color liquid crystal device has a reflectivity of 30% in white display, a contrast ratio of 1:10, and can display four colors of white, red, cyan and black, and the red display color is x = 0. .
38, y = 0.31, cyan display color x = 0.28, y
= 0.32. There is no shadow on the display, and the viewing angle dependency is extremely small. Also, for example, light that enters through a red filter always exits through a red filter,
The display was bright and high in color purity without any color turbidity.

Although the MIM element is used in the above embodiment, a TFT element can be used instead. Fig. 58
FIG. 2 is a diagram showing a main part of a structure in a case where a reflective color liquid crystal device of the present invention in which a reflecting plate is provided between a pair of substrates and only one polarizing plate is arranged using a TFT element. First, the configuration will be described. Reference numeral 5801 denotes an upper polarizing plate; 5802, a counter substrate; 5803, a liquid crystal; 5804, an element substrate; a color filter 5805 and a counter electrode (common electrode) 5806 provided on the counter substrate 5802; Signal line 5807, source signal line 5808, T
FT element 5809, pixel electrode 581 also serving as scattering reflector
0 was provided. In the case of the MIM element, the metal wiring only runs in the vertical direction, but in the case of the TFT element, the metal wiring runs in the vertical and horizontal directions, so that the aperture ratio decreases. Fortunately, this embodiment 36 does not require a lower polarizer. So TF
In the case of using a T element, it is preferable to provide a method in which an insulating film is provided on a layer of the element and the signal line, a reflecting plate serving also as a pixel electrode is provided thereon, and the two are connected through a contact hole.

(Embodiment 37) Embodiment 37 is directed to a reflection type color liquid crystal device in which a reflection plate is provided between a pair of substrates and only one polarizing plate is arranged, wherein the reflection plate is a specular reflection plate, Regarding the substrate having a scattering plate on the outer surface of the substrate located on the light side, first, six examples relating to the reflection type monochrome liquid crystal device will be introduced. Any of these can be used as a reflective color liquid crystal device by adding a color filter.

<First Example> FIG. 59 is a sectional view of a reflection type liquid crystal device in the first example. First, the configuration will be described.
590l is a scattering plate, 5902 is an upper polarizing plate, 5903 is an upper substrate, 5904 is an upper electrode, 5905 is a liquid crystal,
06 is a lower electrode, 5907 is a lower substrate, 5908 is a lower polarizing plate, and 5909 is a specular reflector. The liquid crystal 5905 is twisted 90 degrees in the cell, and the polarizing plates 5902 and 590
The absorption axis 8 is a TN mode that coincides with the slow axis of the liquid crystal 5 at the adjacent interface. Thickness d of liquid crystal 5905 and birefringence △
The product △ n × d of n is 0.48 μm.

The reflection type liquid crystal device having the above configuration has a brightness of 25% and a contrast of 1:15 in the room in the normal direction of the substrate in the room normal direction, and a white display in the regular reflection direction of the ceiling light. Had a brightness of 45% and a contrast of 1:12. Even in the regular reflection direction, the ceiling light is not reflected due to the back scattering effect of the scattering plate, and a high contrast can be obtained. Since light in the regular reflection direction can be effectively used while maintaining sufficient contrast, a very bright display can be obtained.

<Second Example> FIG. 60 shows the reflection type liquid crystal device No. 2 in the second example. No. 1 to No. 3 is a sectional view of FIG. 6
001 is a scattering plate, 6002 is an upper polarizing plate, 6003 is an upper substrate, 6004 is an upper electrode, 6005 is a liquid crystal, 600
6 is a lower electrode, 6007 is a lower substrate, and 6008 is a specular reflector.

FIG. 61 shows the reflective liquid crystal device No. 2 in the second example. No. 1 to No. 3 shows the axial direction of the polarizing plate and the like. 61
01 is the transmission axis direction of the upper polarizing plate 6002, 6103 is the rubbing direction of the upper substrate 6003, and 6103 is the lower substrate 6
007 is a rubbing direction, and 6104 is an upper polarizing plate 6.
002, the angles θ1, 6 formed with the horizontal in the transmission axis direction 6101
Reference numeral 105 denotes an angle θ2 formed by the rubbing direction 6102 of the upper substrate 6003 with the horizontal, and reference numeral 6106 denotes an angle θ3 formed by the rubbing direction 6103 of the lower substrate 6007 with the horizontal. The angle is positive in a counterclockwise direction and is shown from -180 to 180 degrees.

FIG. 62 shows a reflection type liquid crystal device No. 2 in the second example. 4 to No. 4. 6 is a sectional view of FIG. 6201 is a scattering plate, 6202 is an upper polarizing plate, 6203 is a retardation plate, 62
04 is an upper substrate, 6205 is an upper electrode, 6206 is a liquid crystal, 6207 is a lower electrode, 6208 is a lower substrate, 620
9 is a mirror reflection plate.

FIG. 63 shows the reflective liquid crystal device No. 2 in the second example. 4 to No. 4. 6 shows an axial direction of a polarizing plate 6 and the like. 63
01 is the transmission axis direction of the upper polarizing plate 6202, 6302 is the slow axis direction of the retardation plate 6203, 6303 is the upper substrate 62
A rubbing direction 04, a rubbing direction 6304 of the lower substrate 6208, an angle θ1 between 6305 and the horizontal of the transmission axis direction 6301 of the upper polarizing plate 6202, and an angle θ2 between 6306 and the horizontal of the rubbing direction 6303 of the upper substrate 6204. , 6307 are rubbing directions 6 of the lower substrate 6208.
The angle θ3, 6308 between the horizontal plane 304 and the horizontal plane
03 is the angle θ4 formed with the horizontal in the slow axis direction 6302.

These angle conditions and Δn × d,
Table 4 below shows values of the phase difference of the phase difference plate. △ n × in the figure
The unit of d and the phase difference is μm.

[Table 4]

The characteristics are shown in Table 5 below.

[Table 5] As in the first example, sufficient contrast and bright display can be obtained.

<Comparative Example of First and Second Examples> FIG. 64 is a sectional view of a reflective liquid crystal device in a comparative example. 640
1 is an upper polarizing plate, 6402 is an upper substrate, 6403 is an upper electrode, 6404 is a liquid crystal, 6405 is a lower electrode, 6406
Denotes a lower substrate, 6407 denotes a lower polarizing plate, and 6408 denotes a scattering reflector. The liquid crystal 6404 is twisted by 90 degrees in the cell similarly to the first example, and the absorption axes of the polarizing plates 6401 and 6407 are in the TN mode in which the slow axis of the liquid crystal 5 at the close interface is coincident. The product Δn × d of the thickness d of the liquid crystal 6404 and the birefringence Δn is 0.48 μm.

In the reflection type liquid crystal device having the above configuration, the brightness in white display in the normal direction of the substrate is 28% and the contrast is 1:15 in the room, but the ceiling is in the specular reflection direction of the ceiling light. Because of the reflection of the light, the brightness of the white display is 62
%, The contrast was 1: 2, which was not practical.

<Third Example> FIG. 65 is a view showing characteristics of a scattering plate of a reflection type liquid crystal device in a third example. In FIG. 65, 6501 is a scattering plate, 6502 is incident light,
03 is a specular reflected light, and 6504 is a 10 degree cone centered on the specular reflected light 6503. The scattering plate 6501 of the third example scatters 5% of the incident light into the 10 ° cone 6503.

The scattering plate having the above characteristics is described in IEICE Technical Report EI.
As described in D95-146, forward scattering was produced by mixing particles having a different refractive index from that of the medium, and fine scattering was provided on the surface to adjust back scattering. If the scattered light is larger than 10%, the reflection of the light source becomes large and the contrast is reduced. Conversely, if the scattered light is smaller than 0.5%, the display blur becomes too large.

The structure of this embodiment is the same as that of the first embodiment shown in FIG.
The liquid crystal 5905 has the same structure as that shown in FIG.
Twisted to 0 degree, the absorption axes of the polarizing plates 5902 and 5908 match the slow axis of the liquid crystal 5905 at the close interface.
N mode. The thickness d of the liquid crystal 5905 and the birefringence △ n
Is 0.48 μm.

The reflection type liquid crystal device having the above configuration has a brightness of 26% and a contrast of 1:15 in the room in the normal direction of the substrate in the room, and a white display in the regular reflection direction of the ceiling light. Had a brightness of 43% and a contrast of 1:13.

<Fourth Example> The scattering plate shown in FIG. 65 of the third example was applied to the configurations of FIGS. 60 and 62 of the second example.

The axis directions, Δn × d and the phase difference of the liquid crystal shown in FIGS. 61 and 63 were set in the same manner as in the second example. The properties are shown in Table 6 below.

[Table 6] As in the first embodiment, a sufficient contrast and bright display can be obtained.

<Fifth Example> FIG. 66 is a sectional view of a reflection type liquid crystal device in a fifth example. First, the configuration will be described. 6
Reference numeral 601 denotes a scattering plate, 6602 denotes an upper polarizing plate, 6603 denotes an upper substrate, 6604 denotes an upper electrode, 6605 denotes a liquid crystal, and 660 denotes a liquid crystal.
6 is a lower polarizing plate, 6607 is a lower electrode / mirror reflector, 6
608 is a lower substrate. The liquid crystal 6605 is 90
This is a TN mode in which the absorption axes of the polarizing plates 6602 and 6606 are coincident with the slow axis of the liquid crystal 5 at the adjacent interface. The product △ n of the thickness d of the liquid crystal 6605 and the birefringence △ n
× d is 0.48 μm. Aluminum was deposited on the lower electrode, and the polarizing plate was obtained by applying and orienting a solution of a liquid crystalline polymer containing a black dichroic dye on a polyimide alignment film. The same scattering plate as in the third example was used.

The reflection type liquid crystal device having the above configuration has a brightness of 28% and a contrast of 1:18 in white room in the normal direction of the substrate in the room, and a white display in the regular reflection direction of the ceiling light. The brightness was 44% and the contrast was 1:16.

<Sixth Example> FIG. 67 shows the reflective liquid crystal device No. 6 in the sixth example. No. 1 to No. 3 is a sectional view of FIG. 6
Reference numeral 701 denotes a scattering plate, 6702 denotes an upper polarizing plate, 6703 denotes an upper substrate, 6704 denotes an upper electrode, 6705 denotes a liquid crystal, and 670 denotes a liquid crystal.
Reference numeral 6 denotes a lower electrode / mirror reflector, and reference numeral 6707 denotes a lower substrate.

FIG. 61 shows the reflective liquid crystal device No. 6 in the sixth example. No. 1 to No. 3 shows the axial direction of the polarizing plate and the like. 61
01 is the transmission axis direction of the upper polarizing plate 6002, 6103 is the rubbing direction of the upper substrate 6003, and 6103 is the lower substrate 6
007 is a rubbing direction, and 6104 is an upper polarizing plate 6.
002, the angles θ1, 6 formed with the horizontal in the transmission axis direction 6101
Reference numeral 105 denotes an angle θ2 formed by the rubbing direction 6102 of the upper substrate 6003 with the horizontal, and reference numeral 6106 denotes an angle θ3 formed by the rubbing direction 6103 of the lower substrate 6007 with the horizontal.

FIG. 68 shows the reflective liquid crystal device No. 6 in the sixth example. 4 to No. 4. 6 is a sectional view of FIG. 6801 is a scattering plate, 6802 is an upper polarizing plate, 6803 is a retardation plate, 68
04 upper substrate, 6805 is upper electrode, 6806 is liquid crystal,
Reference numeral 6807 denotes a lower electrode / mirror reflector, and reference numeral 6808 denotes a lower substrate.

FIG. 63 shows the reflective liquid crystal device No. 6 in the sixth example. 4 to No. 4. 6 shows an axial direction of a polarizing plate 6 and the like. 63
01 is the transmission axis direction of the upper polarizing plate 6202, 6302 is the slow axis direction of the retardation plate 6203, 6303 is the upper substrate 62
A rubbing direction 04, a rubbing direction 6304 of the lower substrate 6208, an angle θ1 between 6305 and the horizontal of the transmission axis direction 6301 of the upper polarizing plate 6202, and an angle θ2 between 6306 and the horizontal of the rubbing direction 6303 of the upper substrate 6204. , 6307 are rubbing directions 6 of the lower substrate 6208.
The angle θ3, 6308 between the horizontal plane 304 and the horizontal plane
03 is the angle θ4 formed with the horizontal in the slow axis direction 6302.

The conditions of the angle, Δn × d of the liquid crystal, and the phase difference of the retardation plate are the same as those in Table 4 shown in the second example. The same scattering plate as in the third example was used.

Table 7 below shows the characteristics of the reflective liquid crystal display device having the above structure.

[Table 7] In each case, a sufficient contrast and a bright display can be obtained.

Each of the six reflective monochrome liquid crystal devices described above can be used as a reflective color liquid crystal device by adding a color filter. An example is shown below.

FIG. 69 is a diagram showing a main part of a reflection type color liquid crystal device according to the embodiment 37 of the invention. 6901
Denotes a scattering plate, 6902 denotes an upper polarizing plate, 6903 denotes a phase plate, 6904 denotes an upper substrate, 6905 denotes a liquid crystal, 6906 denotes a lower substrate, 6907 denotes a counter electrode (scanning line), 6908 denotes a signal line, and 6909 denotes a pixel electrode. A specular reflector, 6910 is an MIM element, and 6911 is a color filter. The distance between pixels is 160 μm in both directions perpendicular and parallel to the signal line.
m, the width of the signal line is 10 μm, the gap between the signal line and the pixel electrode is 10 μm, and the distance between adjacent pixel electrodes is 1
It was set to 0 μm.

FIG. 63 shows the axial direction of the polarizing plate and the like. 630
1 is the transmission axis direction of the upper polarizing plate 6202, 6302 is the slow axis direction of the phase difference plate 6203, and 6303 is the upper substrate 620.
The rubbing direction of No. 4, 6304 is the rubbing direction of the lower substrate 6208, 6305 is the angle θ1 between the horizontal of the transmission axis direction 6301 of the upper polarizing plate 6202, and 6306 is the angle θ2 between the horizontal of the rubbing direction 6303 of the upper substrate 6204. , 6307 are rubbing directions 63 of the lower substrate 6208.
04 and the horizontal angle θ3, 6308 are the phase difference plate 620.
3 is an angle θ4 formed with the horizontal in the slow axis direction 6302.

Δn × d of the liquid crystal 6905 is 0.33 μm,
θ1 is −82 degrees, θ2 is −74 degrees, θ3 is 74 degrees, θ4
Is set to 9 degrees, the phase difference of the phase difference plate 6903 is set to 0.31 μm, and the pixel electrode and mirror reflection plate 690 is also provided on the signal line 6908.
9 in the same manner as above.

The same scattering plate as in the third example was used. The color filter 6911 has an average transmittance of 75%.
(C in the figure) and red (R in the figure) color filters were used.

In the reflection type liquid crystal device having the above configuration, the brightness in white display in the normal direction of the substrate is 30%, the contrast is 1:15 in the room, and the white display in the regular reflection direction of the ceiling light is performed. Had a brightness of 51% and a contrast of 1:12. In each case, the display color of red is x = 0.39, y = 0.
32, cyan had x = 0.28 and y = 0.31.
The color can be recognized sufficiently and the display is bright.

(Embodiment 38) Embodiment 38 is directed to a reflection type color liquid crystal device characterized in that a reflection plate is provided between a pair of substrates and only one polarizing plate is disposed, or the reflection plate is a mirror surface. In the reflection type color liquid crystal device, which is a reflection plate and has a scattering plate on the outer surface of the substrate located on the incident light side, the liquid crystal on the metal wiring is oriented similarly to the liquid crystal in the pixel portion. Regarding the reflection type color liquid crystal device, first, two examples regarding the reflection type monochrome liquid crystal device will be introduced. All of these can be achieved by adding color filters.
It can be used as a reflective color liquid crystal device.

<First Example> FIG. 70 is a diagram showing a main part of a reflection type liquid crystal device according to a first example. 7001 is a scattering plate, 7002 is an upper polarizing plate, 7003 is an upper substrate, 70
04 is a liquid crystal, 7005 is a lower substrate, 7006 is a lower polarizing plate, 7007 is a specular reflector, 7008 is a counter electrode (scanning line), 7009 is a signal line, 7010 is a pixel electrode, 701
1 is an MIM element. The liquid crystal 7004 is twisted by 90 degrees in the cell, and is in a TN mode in which the absorption axes of the polarizing plates 7002 and 7006 coincide with the slow axis of the liquid crystal 7004 at the close interface. The product Δn × d of the thickness d of the liquid crystal 7004 and the birefringence Δn is 0.48 μm. Example 37 was used for the scattering plate.
The same one as in the third example was used.

The distance between pixels is set to 160 μm in both directions perpendicular to and parallel to the signal line, the width of the signal line is set to 10 μm, the gap between the signal line and the pixel electrode is set to 10 μm, and the distance between adjacent pixel electrodes is set to 10 μm. did.

In the reflective liquid crystal device having the above structure, the signal line 7
A region other than the pixel portion of the counter electrode 7008 and the region above the pixel electrode 7010 was subjected to rubbing treatment in the same manner as the region on the pixel electrode 7010 to arrange the liquid crystals. %, Contrast is 1:14
And the brightness of the white display in the specular reflection direction of the ceiling light is 43
% And contrast were 1:11.

By the way, since the wettability of the metal electrode is different from that of the ITO of the pixel electrode, it is often repelled even if an alignment film is applied. In such a case, that is, when the alignment process is not performed on the signal line 7009, the brightness at the time of white display in the room normal direction in the room is 19% and the contrast is 1:
14, the brightness of white display in the specular reflection direction of the ceiling light was 40%, and the contrast was 1:11.

In each case, a high contrast and a very bright display could be obtained. However, a brighter display could be obtained by performing the alignment treatment on the metal wiring.

<Second Example> FIG. 71 shows a reflection type liquid crystal device No. 2 in the second example. 1 and No. FIG. 3 is a diagram showing a main part of No. 3; 7101 is a scattering plate, 7102 is an upper polarizing plate, 710
3 is an upper substrate, 7104 is a liquid crystal, 7105 is a lower substrate,
7106 is a mirror reflector, 7107 is a counter electrode (scanning line), 7108 is a signal line, 7109 is a pixel electrode, 711
0 is an MIM element. The distance between pixels is set to 160 μm in both directions perpendicular and parallel to the signal line, and the width of the signal line is set to 1 μm.
The distance between the signal line and the pixel electrode was 10 μm, and the distance between adjacent pixel electrodes was 10 μm.

FIG. 61 shows the reflective liquid crystal device No. 2 in the second example. No. 1 to No. 3 shows the axial direction of the polarizing plate and the like. 61
01 is the transmission axis direction of the upper polarizing plate 6002, 6103 is the rubbing direction of the upper substrate 6003, and 6103 is the lower substrate 6
007 is a rubbing direction, and 6104 is an upper polarizing plate 6.
002, the angles θ1, 6 formed with the horizontal in the transmission axis direction 6101
Reference numeral 105 denotes an angle θ2 formed by the rubbing direction 6102 of the upper substrate 6003 with the horizontal, and reference numeral 6106 denotes an angle θ3 formed by the rubbing direction 6103 of the lower substrate 6007 with the horizontal.

FIG. 72 shows the reflective liquid crystal device No. 2 in the second example. 2 and No. FIG. 4 is a diagram showing a main part of FIG. 720
1 is a scattering plate, 7202 is a phase difference plate, 7203 is an upper polarizing plate, 7204 is an upper substrate, 7205 is a liquid crystal, 7206 is a lower substrate, 7207 is a mirror reflector, 7208 is a counter electrode (scanning line), and 7209 is a signal. Line, 7210 is a pixel electrode,
Reference numeral 7211 denotes an MIM element. The distance between pixels was set to 160 μm in both directions perpendicular to and parallel to the signal line, the width of the signal line was set to 10 μm, the gap between the signal line and the pixel electrode was set to 10 μm, and the distance between adjacent pixel electrodes was set to 10 μm.

FIG. 63 shows the reflective liquid crystal device No. 2 in the second example. 4 to No. 4. 6 shows an axial direction of a polarizing plate 6 and the like. 63
01 is the transmission axis direction of the upper polarizing plate 6202, 6302 is the slow axis direction of the retardation plate 6203, 6303 is the upper substrate 62
A rubbing direction 04, a rubbing direction 6304 of the lower substrate 6208, an angle θ1 between 6305 and the horizontal of the transmission axis direction 6301 of the upper polarizing plate 6202, and an angle θ2 between 6306 and the horizontal of the rubbing direction 6303 of the upper substrate 6204. , 6307 are rubbing directions 6 of the lower substrate 6208.
The angle θ3, 6308 between the horizontal plane 304 and the horizontal plane
03 is the angle θ4 formed with the horizontal in the slow axis direction 6302.

The same scattering plate as that of the third example of Example 37 was used. In the reflective liquid crystal device having the above configuration, N
o. 1 and No. No. 2 is obtained by subjecting an area other than the pixel portion to an alignment process. 3 and No. In No. 4, only the pixel portion was subjected to an alignment treatment.

Table 8 below shows Δn × d of the liquid crystal 7205, angles of the polarizing plates and the like, and phase differences of the retardation plates.

[Table 8]

The characteristics are shown in Table 9 below.

[Table 9]

In any of the examples, a bright display with high contrast can be obtained. However, a brighter display can be obtained by performing the alignment treatment on the region other than the pixel portion.

(Embodiment 39) Embodiment 39 relates to a reflective color liquid crystal device whose display is a normally white type. First, an example relating to a reflective monochrome liquid crystal device will be introduced. This can be used as a reflection type color liquid crystal device by adding a color filter.

FIG. 59 shows a reflective liquid crystal device N according to the thirty-ninth embodiment.
o. 1, No. 2 is a sectional view of FIG. First, the configuration will be described. 5901 is a scattering plate, 5902 is an upper polarizing plate, 590
3 is an upper substrate, 5904 is an upper electrode, 5905 is a liquid crystal,
5906 is a lower electrode, 5907 is a lower substrate, 5908 is a lower polarizing plate, and 5909 is a specular reflector. LCD 590
No. 5 is twisted at 90 degrees in the cell. 1 denotes a liquid crystal 59 at the interface where the absorption axes of the polarizing plates 5902 and 5908 are close to each other.
No. 05 coincides with the slow axis. 2 is the liquid crystal 5 at the interface where the absorption axis of the polarizing plate 5902 and the absorption axis of 5908 are close to each other.
The TN mode coincides with the slow axis 905. LCD 59
The product Δn × d of the thickness d and the birefringence △ n of 05 is 0.48μ
m. The same scattering plate as that of the third example of Example 37 was used.

FIG. 73 is a view showing a voltage transmittance characteristic of the reflection type liquid crystal device of Example 37. Here, 7301 is No.
7 shows how the transmittance changes with respect to the voltage of 1;
Is No. 7 shows how the transmittance changes with respect to a voltage of 2.
No. No. 1 is normally white, No. 1 2 is a normally black display.

The reflection type liquid crystal device having the above-mentioned configuration is the 1
In the room, the brightness of white display in the normal direction of the substrate is 25% and the contrast is 1:15, the brightness of white display in the regular reflection direction of the ceiling light is 45%, and the contrast is 1:12. Met. No. Reference numeral 2 indicates that in a room, the brightness of white display in the normal direction of the substrate is 23% and the contrast is 1:15, the brightness of white display in the regular reflection direction of the ceiling light is 42%, and the contrast is 1: It was 13.

In both cases, a sufficient contrast and bright display can be obtained, but a brighter display can be obtained in the normally white mode. This is because the area outside the pixel contributes to the brightness and because it has a viewing angle characteristic in which light incident from an oblique direction is easily transmitted.

(Embodiment 40) In the case where display is performed by the reflection type color liquid crystal device in the above embodiments 1 to 39, a problem arises that does not exist in the conventional transmission type color liquid crystal device. That is, a single dot does not sufficiently generate color, and the same color needs to be displayed over a certain wide area in order to display a color. This is because the color of the color filter is pale, the distance between the liquid crystal layer and the reflection plate is large (excluding Examples 36 to 39), and the colors of adjacent dots are easily mixed.

Therefore, a method of displaying black characters on a white background and making a part of the background red, that is, a method of using a marker, is more suitable than a method of displaying red characters on a white background. However, the fact that a single pixel does not sufficiently develop a color means that a monochrome liquid crystal device can be easily displayed in black and white.

The reflection type color liquid crystal device of the embodiment 40 has
One pixel is constituted by dots. A pixel is the smallest unit that can achieve the functions required for display.
In an ordinary color liquid crystal device, one pixel is composed of a total of three dots of red, green and blue. Therefore, 480 × 640 × 3 dots were required to perform 480 × 640 pixel VGA display. When two color filters of cyan and red are used, 480 × 640 × 2 dots are required. However, Embodiment 40 can perform VGA display with 480 × 640 pixels while being a color liquid crystal device.

The structure of the fortieth embodiment is the same as, for example, the fifth embodiment. However, in the case of displaying, the following measures are taken. An example is shown in FIG. 74, and description will be made along this figure. Here, 16 × 48 pixels are shown. (A)
Is a diagram showing an arrangement of color filters, in which red (shown by “R”) and cyan (shown by “C”) are arranged in a mosaic pattern. (B) and (c) are diagrams showing the distribution of on dots and off dots. On-dots are indicated by hatching because they are dark displays. The display in (b) is a display in which the LCD is turned on ignoring the color filter array. However, as described above, since this reflective type color liquid crystal device does not produce sufficient color with a single dot, "LCD" appears black on a white background. Therefore, black and white display is possible at the resolution of VGA. On the other hand, the display of (c) is (b)
Only the cyan dots on the background are turned on, and "LCD" is displayed in red in black. When the same color is displayed over an area of 10 dots or more, it becomes possible to display the color.

In addition to the use as a marker, for example, when displaying map information, it is possible to color only a specific route if the road width is several dots. In addition, since icons and the like on a personal computer screen have a certain area, they can be displayed in color.

(Example 41) The reflection type color liquid crystal devices in Examples 1 to 40 were adopted as a display of an electronic apparatus.

FIG. 75 is a diagram showing an example of an electronic apparatus employing the reflection type color liquid crystal device according to the first to forty embodiments. This is the so-called PDA (Personal Di)
a Digital Assistant), which is a type of portable information terminal. Reference numeral 7501 denotes a reflective color liquid crystal device, on which a tablet for pen input is mounted. Conventionally, a reflection type monochrome liquid crystal device or a transmission type color liquid crystal device has been used for a PDA display. By replacing these with a reflective color liquid crystal device, there is an advantage that the amount of information is greatly increased by color display as compared with the former, and there is an advantage that the battery life is longer and the size and weight are reduced as compared with the latter.

FIG. 76 is a view showing an example of the electronic apparatus of the forty-first embodiment in which the display unit is mounted so as to be movable with respect to the main body so that ambient light can be efficiently reflected to an observer. This is a so-called digital still camera. Reference numeral 7601 denotes a reflection type color liquid crystal device, which is attached so that the angle with respect to the main body can be changed.
Although not shown, the lens is located on the back side of the reflection type color liquid crystal device mounting portion. Conventionally, transmission type color liquid crystal devices have been used for displays for digital still cameras. By replacing this with a reflective type color liquid crystal device, not only the battery life is extended and the size is reduced, but also the visibility under direct sunlight is remarkably improved. This is because the transmissive color liquid crystal device is difficult to see when the surface reflection is large under direct sunlight because the brightness of the backlight is limited, but the reflective color liquid crystal device becomes brighter as the ambient light becomes brighter. It is. In order to effectively use the ambient light, it is effective to mount the liquid crystal device so that the angle of the liquid crystal device can be changed.

The reflection type color liquid crystal device may be a palmtop PC, a subnotebook PC, a notebook PC, etc.
C, handy terminal, camcorder, LCD TV,
It can be applied to various electronic devices that emphasize portability such as game machines, electronic organizers, mobile phones, and pagers.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main part of the structure of a reflective type color liquid crystal device in Examples 1 to 4, 27, 29, and 33 of the present invention.

FIG. 2 is a diagram illustrating spectral characteristics of a color filter of the reflective color liquid crystal device according to the first embodiment of the present invention.

FIG. 3 shows Examples 2, 3, 5, 23, 29, and 3 of the present invention.
It is a figure which shows the spectral characteristic of the color filter of the reflection type color liquid crystal device in 1, 32, 34, 36, 40.

FIG. 4 is a diagram plotting a change in contrast when the thickness of an element substrate is changed in a reflective color liquid crystal device according to a third embodiment of the present invention.

FIG. 5 is a diagram illustrating spectral characteristics of a color filter of a reflective color liquid crystal device according to a fourth embodiment of the present invention.

FIG. 6 shows Examples 5, 6, 23, 27, 32, and 4 of the present invention.
FIG. 2 is a diagram showing a main part of the structure of the reflective color liquid crystal device at 0.

FIG. 7 is a diagram illustrating spectral characteristics of a color filter of a reflective color liquid crystal device according to a sixth embodiment of the present invention.

FIG. 8 is a diagram showing a main part of the structure of a reflective type color liquid crystal device in Examples 7, 9, 24, 27, and 28 of the present invention.

FIG. 9 is a diagram illustrating spectral characteristics of a color filter of a reflective color liquid crystal device according to a seventh embodiment of the present invention.

FIG. 10 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to Embodiments 8 and 10 of the present invention.

FIG. 11 is a diagram illustrating spectral characteristics of a color filter of a reflective color liquid crystal device according to an eighth embodiment of the present invention.

FIG. 12 is a diagram showing the spectral characteristics of the color filters of the reflective color liquid crystal device in Examples 9, 24, 25, and 26 of the present invention.

FIG. 13 is a diagram illustrating spectral characteristics of a color filter of a reflective color liquid crystal device according to a tenth embodiment of the present invention.

FIG. 14 is a diagram plotting changes in average transmittance when the thickness of a color filter is changed in a reflective type color liquid crystal device according to Example 10 of the present invention.

FIG. 15 is a diagram showing a main part of the structure of a reflective type color liquid crystal device according to embodiments 11, 12, and 15 of the present invention.

FIG. 16 is a diagram showing the spectral characteristics of the color filters of the reflective color liquid crystal device in Examples 11, 21, and 26 of the present invention.

FIG. 17 is a diagram plotting a change in average transmittance when a ratio of an area where a color filter is provided is changed in a reflection type color liquid crystal device according to Example 11 of the present invention.

FIG. 18 is a diagram illustrating spectral characteristics of a color filter of a reflection type color liquid crystal device in Examples 12 and 26 of the present invention.

FIG. 19 is a diagram plotting the change in average transmittance when the ratio of the area where a color filter is provided is changed in the reflective color liquid crystal device according to Example 12 of the present invention.

FIG. 20 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to Examples 13 and 15 of the present invention.

FIG. 21 is a diagram illustrating a main part of the structure of a reflective color liquid crystal device according to Examples 14 and 15 of the present invention.

FIG. 22 is a diagram illustrating a voltage reflectance characteristic of a reflective color liquid crystal device according to Embodiment 15 of the present invention.

FIG. 23 is a diagram showing a structure of a color filter substrate of a reflection type color liquid crystal device in Embodiment 16 of the present invention.

FIG. 24 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to Embodiment 16 of the present invention.

FIG. 25 is a diagram illustrating spectral characteristics of a color filter of a reflective color liquid crystal device according to Embodiment 16 of the present invention.

FIG. 26 is a diagram showing an average spectral characteristic within one dot of a color filter of a reflection type color liquid crystal device in Examples 16 and 17 of the present invention.

FIG. 27 is a diagram showing a structure of a color filter substrate of a reflective color liquid crystal device in a comparative example referred to in Embodiment 16 of the present invention.

FIG. 28 is a diagram showing a structure of a color filter substrate of a reflection type color liquid crystal device in Embodiment 17 of the present invention.

FIG. 29 is a diagram showing the spectral characteristics of the color filters of the reflective color liquid crystal device in Embodiment 17 of the present invention.

FIG. 30 is a diagram illustrating spectral characteristics of a color filter of a reflection type color liquid crystal device in Embodiment 17 of the present invention.

FIG. 31 is a diagram illustrating spectral characteristics of a color filter of a reflection type color liquid crystal device in Embodiment 17 of the present invention.

FIG. 32 is a diagram showing an arrangement of color filters of a reflective type color liquid crystal device according to Embodiment 18 of the present invention.

FIG. 33 is a diagram illustrating a main part of the structure of a reflective color liquid crystal device according to a twenty-first embodiment of the present invention.

FIG. 34 is a diagram illustrating an arrangement of a color filter of a reflective color liquid crystal device according to a twenty-first embodiment of the present invention.

FIG. 35 is a diagram illustrating an arrangement of a color filter of a reflective color liquid crystal device according to a twenty-first embodiment of the present invention.

FIG. 36 is a diagram illustrating an arrangement of a color filter of a reflective color liquid crystal device according to Embodiment 21 of the present invention.

FIG. 37 is a view schematically showing a structure of a reflective color liquid crystal device in Embodiment 22 of the present invention.

FIG. 38 is a diagram showing an arrangement of a color filter of a reflection type color liquid crystal device in Embodiment 23 of the present invention.

FIG. 39 is a diagram illustrating an arrangement of a color filter of a reflective type color liquid crystal device according to Embodiment 24 of the present invention.

FIG. 40 is a diagram illustrating a main part of the structure of a reflective color liquid crystal device according to Embodiment 25 of the present invention.

FIG. 41 is a diagram showing an arrangement of a color filter of a reflection type color liquid crystal device in Embodiment 25 of the present invention.

FIG. 42 is a diagram illustrating a main part of a structure of a reflective color liquid crystal device according to Embodiment 26 of the present invention.

FIG. 43 is a diagram illustrating a wiring method of an MIM element of a reflection type color liquid crystal device in Example 28 of the present invention.

FIG. 44 is a diagram illustrating a wiring method of an MIM element of a reflection type color liquid crystal device in a comparative example referred to in Example 28 of the invention.

FIG. 45 is a diagram plotting changes in contrast and reflectance when the driving area is changed in the reflective color liquid crystal device according to Example 29 of the present invention.

FIG. 46 is a diagram for explaining scattering characteristics of a reflector of a reflective type color liquid crystal device according to embodiment 30 of the present invention.

FIG. 47 is a diagram showing the scattering characteristics of the reflector of the reflective type color liquid crystal device according to the working example 30 of the invention.

FIG. 48 is a diagram plotting brightness and contrast ratio when the ratio of light reflected in a 30-degree cone is changed in the reflective color liquid crystal device according to Example 30 of the present invention.

FIG. 49 is a diagram illustrating a main part of a structure of a reflective color liquid crystal device according to Embodiment 31 of the present invention.

FIG. 50 is a diagram illustrating a relationship between axes of a reflection type color liquid crystal device in Examples 32 and 33 of the present invention.

FIG. 51 is a diagram plotting changes in the reflectance of white display when Δn × d of the liquid crystal cell is changed in the reflective color liquid crystal device according to Example 33 of the present invention.

FIG. 52 is a diagram illustrating a main part of a structure of a reflective color liquid crystal device according to Embodiment 34 of the present invention.

FIG. 53 is a diagram illustrating a relationship between axes of a reflective color liquid crystal device according to Examples 34 and 35 of the present invention.

FIG. 54 is a diagram illustrating spectral characteristics of a color filter of a reflective color liquid crystal device according to Example 35 of the present invention.

FIG. 55 is a diagram illustrating a main part of the structure of a reflective color liquid crystal device according to a working example 35 of the invention.

FIG. 56 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to Embodiment 36 of the present invention.

FIG. 57 is a diagram illustrating a relationship among axes of a reflective color liquid crystal device according to a working example 36 of the invention.

FIG. 58 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to Embodiment 36 of the present invention.

FIG. 59 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to Examples 37 and 39 of the present invention.

FIG. 60 is a diagram illustrating a main part of the structure of a reflective color liquid crystal device according to a working example 37 of the invention.

FIG. 61 is a diagram illustrating a relationship between axes of a reflective color liquid crystal device in Examples 37 and 38 of the present invention.

FIG. 62 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to a working example 37 of the invention.

FIG. 63 is a diagram showing a relationship between axes of a reflection type color liquid crystal device in Examples 37 and 38 of the present invention.

FIG. 64 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to a working example 37 of the invention.

FIG. 65 is a diagram illustrating characteristics of a scattering plate of a reflective color liquid crystal device according to Example 37 of the present invention.

FIG. 66 is a diagram showing a main part of a structure of a reflective color liquid crystal device in a working example 37 of the invention.

FIG. 67 is a diagram illustrating a main part of the structure of a reflective color liquid crystal device in a working example 37 of the invention.

FIG. 68 is a diagram showing a main part of the structure of a reflective color liquid crystal device in embodiment 37 of the present invention.

FIG. 69 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to a working example 37 of the invention.

FIG. 70 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to a working example 38 of the invention.

FIG. 71 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to a working example 38 of the invention.

FIG. 72 is a diagram showing a main part of the structure of a reflective color liquid crystal device according to a working example 38 of the invention.

FIG. 73 is a diagram showing a voltage transmittance characteristic of a reflective type color liquid crystal device in Example 39 of the present invention.

FIG. 74 is a diagram illustrating an example of a display method of a reflective color liquid crystal device in Example 40 of the present invention.

FIG. 75 is a diagram illustrating an example of an electronic apparatus using the reflective color liquid crystal device in Embodiment 41 of the present invention.

FIG. 76 is a diagram illustrating an example of an electronic apparatus using the reflective color liquid crystal device in Embodiment 41 of the present invention.

FIG. 77 is a view for explaining a problem of parallax peculiar to a reflective color liquid crystal device.

FIG. 78 is a diagram illustrating spectral characteristics of a color filter of a conventional transmission type color liquid crystal device.

FIG. 79: A paper by Tatsuo Uchida et al. (IEEE Trans
actions on Electron Device
es, Vol. ED-33, no. 8, pp. 1207
1211 (1986)). FIG. 8 is a diagram illustrating spectral characteristics of a color filter proposed in FIG.

FIG. 80: A paper by Seiichi Mitsui et al. (SID92 DIG)
EST, pp. 437-440 (1992))
g. FIG. 3 is a diagram illustrating spectral characteristics of a color filter proposed in No. 2;

FIG. 81 is a diagram showing the spectral characteristics of the color filters proposed in FIGS. 2 (a), (b), and (c) of JP-A-5-241143.

[Explanation of symbols]

FIG. First, the configuration will be described. 801 is an upper polarizing plate,
802 is a counter substrate, 803 is a liquid crystal, 804 is an element substrate,
Reference numeral 805 denotes a lower polarizing plate, reference numeral 806 denotes a scattering reflector, and a color filter 807 and a counter electrode (scanning line) 808 are provided on the counter substrate 802. A signal line 809, a pixel electrode 810, and the like are provided on the element substrate 804. An MIM element 811 was provided.
On the upper polarizing plate, a weak anti-glare treatment was applied in order to suppress glare of illumination light.

 ──────────────────────────────────────────────────続 き Continued on the front page (31) Priority claim number Japanese Patent Application No. Hei 8-94551 (32) Priority date April 16, 1996 (April 16, 1996) (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 8-94552 (32) Priority date April 16, 1996 (April 16, 1996) (33) Country claiming priority Japan (JP) (72) Inventor Tsuyoshi Maeda In Seiko Epson Corporation, 3-3-5, Yamato, Suwa-shi, Nagano Prefecture (72) Inventor Toshiharu Matsushima 3-5-2, Yamato, Suwa-shi, Nagano Prefecture, in Seiko Epson Corporation

Claims (4)

[Claims] 1. A pair of substrates having electrodes formed on an inner surface thereof are opposed to each other. Wiring is formed on an inner surface of one of the pair of substrates, and formed on the one substrate. In the reflective color liquid crystal device in which the electrode is connected to the wiring, one of the pair of substrates includes a reflective layer, and has a dot formed at an overlapping position of the electrode. One dot is formed by the dot of the above. A color filter of a different color is arranged corresponding to each dot constituting the one pixel, and the short side direction of each dot constituting the one pixel is A reflective color liquid crystal device, which is arranged along the wiring. 2. The reflective color liquid crystal device according to claim 1, further comprising: a dot provided with red, blue, and green color filters;
Dots provided with the blue color filters correspondingly,
A reflective color liquid crystal device, wherein the one pixel is formed by dots provided in correspondence with the green color filters. 3. An electronic apparatus comprising the reflective color liquid crystal device according to claim 1 as a display unit. 4. The electronic device according to claim 3, wherein the display unit of the reflective color liquid crystal device is mounted so as to be movable with respect to the main body so that ambient light can be efficiently reflected to an observer. Electronic equipment characterized.