JP3386046B2 - Reflective color liquid crystal device and electronic equipment using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art First of all, a display mounted on a portable information terminal needs to 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 is mainly used for monochrome display, and good reflection type color display has not been obtained yet.

The development of a reflective color liquid crystal device was conducted in 1980.
It seems that it has started in earnest since the mid-era. Prior to that, there was only recognition that reflective color display could be performed by replacing the backlight of a transmissive color liquid crystal device with a reflective plate, as disclosed in Japanese Patent 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 the polarizing plate,
Two or more are discarded, the second is that more than two-thirds of the light is further discarded by the color filter, and finally the problem of parallax. The problem of parallax is unavoidable in the TN (twisted nematic) mode and STN (super twisted nematic) mode that are generally used in transmissive liquid crystal devices. This is because two polarizing plates are always used in these modes, so that a non-negligible gap occurs between the reflecting plate and the liquid crystal layer unless a polarizing plate is built in the cell. Note that the parallax problem here refers not only to the problem of double reflection of the display that was also present in the conventional reflective monochrome liquid crystal device, but also to the problem peculiar to the reflective color liquid crystal device.

The problem of parallax will be described with reference to the drawings. 77 (a) and 77 (b) are sectional views of a reflective color liquid crystal device utilizing the TN mode or the 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 red, green, and blue color filters 7707. There are other transparent electrodes, alignment films, insulating films, etc. 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 parallax problems. One of them is the cancellation of colors. In FIG. 77 (a), an observer 771
2 sees the reflected light 7711 that has come out through the green filter, but this light is the light 7713 that has entered through the red, green, and blue filters and has been scattered and reflected by the light reflecting plate and mixed. It is a thing. If the thickness of the lower glass substrate is sufficiently thicker than the pitch of the color filters, the light coming through the filters of any color will mix with equal probability. However, red → green,
Light passing through the blue-> green path is absorbed by any of the color filters and becomes black, and only light that passes through the green-> green path remains. The same thing can be said for the reflected light coming out through the blue and red filters, so that there is a problem that the brightness of white display is ⅓ of the brightness 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 portion of the liquid crystal layer 7703 that is hatched in a lattice shape is in a non-lighting state (dark state). Incident light 7713 passes through the red, green, and blue dots with equal probability, but 2/3 of them are absorbed by the red and blue dots in the off state. Further, after being scattered by the light reflecting plate and mixed, 2/3 is absorbed by the red and blue dots in the off state again, and reaches the observer 7712. Therefore, the green display is "1/9 the brightness of the white display minus the absorbed amount of the green filter" and becomes very dark. As described above, it is very difficult to use the TN mode or the STN mode having the parallax problem in the reflective color liquid crystal device.

Therefore, conventionally, attempts have been made to change the liquid crystal mode to obtain a bright reflective color display. 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 Section 2, the PCGH (phase transition type guest host) mode which does not require a polarizing plate is adopted. Also, in JP-A-5-241143, a polarizing plate is not required to realize a reflective color liquid crystal device.
DLC (polymer dispersed liquid crystal) mode is adopted. When the liquid crystal mode that does not require a polarizing plate is used, not only the absorption of light by the polarizing plate is eliminated, but also a parallax problem can be basically eliminated by providing a reflector plate adjacent to the liquid crystal layer. On the other hand, however, there is a problem that the liquid crystal mode that does not require a polarizing plate generally has a low contrast, and particularly in the PCGH mode, there is a hysteresis in the voltage transmittance characteristic and halftone display cannot be performed. Further, these liquid crystal modes in which another substance is added to the liquid crystal have many problems in terms of reliability. Therefore, the TN mode and STN, which have been widely used and have a proven record, are also used.
If you can use the mode, you're good to go.

Further, conventionally, an attempt has been made to obtain a bright reflection type color display by using a bright color filter.
In general, a color filter used in a transmissive color liquid crystal device has a spectral characteristic as shown in FIG. In FIG. 78, the horizontal axis represents the wavelength of light and the vertical axis represents the transmittance.
Reference numeral 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 about 38
0 nm to 780 nm wavelength range, especially 450n
High visibility in the wavelength range of m to 660 nm. The color filters of FIG. 78 all have a transmittance of 10 in this range.
There are wavelengths below 100%, and a lot of light is wasted. Further, when the value obtained by simply averaging the transmittance in this wavelength range is 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%.

Brighter color filters are needed for use in reflective color liquid crystal devices. Therefore, in the above paper by Tatsuo Uchida et al. It has been proposed to use two color filters having complementary colors as shown in FIG. 8 to make them brighter than the case of three colors. The spectral characteristics are shown in FIG. 79. 79, the horizontal axis represents the wavelength of light and the vertical axis represents the reflectance. 7901 is the spectrum of the green filter and 7902 is the spectrum of the magenta filter. It is necessary to be careful when comparing because the vertical axis is displayed as reflectance, but again 450 nm to 660 nm
The transmittance of each color filter is 10 in the wavelength range of
There are wavelengths below%. The average transmittance was 41% for the green filter and 48% for the magenta filter.

In addition, a paper by Seiichi Mitsui et al. (SID92
DIGEST, pp. 437-440 (199
2)) also relates to a reflection type color liquid crystal device adopting the same PCGH mode. Two
It uses a bright two-color filter as shown in. Its spectral characteristics are shown in FIG. In FIG. 80, the horizontal axis represents the wavelength of light and the vertical axis represents 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.
Smaller than. The average transmittance was 68% for the green filter and 67% for the magenta filter. In addition, in the same paper,
Since the reflector 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 secured even with such a bright color filter.

The color filter proposed in FIGS. 2 (a), (b), and (c) of the above-mentioned Japanese Patent Laid-Open No. 5-241143 is not yellow, not three colors of red, green and blue. ,
The three colors, cyan and magenta, are used for brightening.
The spectral characteristics are shown in FIG. 81, the horizontal axis represents the wavelength of light and the vertical axis represents 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 compare because the vertical axis is the reflectance and the axis is not graduated, but the transmittance is 10% or less for all color filters in the wavelength range of 450 nm to 660 nm. There is no doubt that wavelength exists. When the average transmittance was roughly estimated, it 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 efforts to develop the reflective type color liquid crystal device were based on the idea of obtaining a bright display by combining the bright liquid crystal mode without using the polarizing plate and the bright color filter. However, even though it is a bright color filter, 450 nm to 660 nm
In many cases, a color filter having a wavelength with a transmittance of less than 10% in the above wavelength range was used.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a reflective color liquid crystal device capable of bright display and electronic equipment using the same.

[0012]

According to a first aspect of the present invention, there is provided a reflection type color liquid crystal device comprising a pair of substrates arranged to face each other and provided with a color filter and a reflection plate. A plurality of dots formed between the electrodes formed on the plurality of dots, the plurality of dots having a light-modulatable region, and the color filter has a plurality of dots in each of the plurality of dots. It is arranged in a part of a possible area, and a black mask and a color filter are not provided in the area between the plurality of dots.

According to a second aspect of the present invention, in the reflective color liquid crystal device according to the first aspect, the color filter is arranged so as to correspond to substantially the center of the dot. It is a thing.

According to a third aspect of the present invention, in the reflective color liquid crystal device according to the first or second aspect, a transparent layer is arranged in a region in each of the dots where the color filter is not formed. It is characterized by that.

According to a fourth aspect of the present invention, in the reflective color liquid crystal device according to any one of the first to third aspects, a transparent layer is arranged in a region between the plurality of dots. It is characterized by that.

According to a fifth aspect of the present invention, in the reflective color liquid crystal device according to the third or fourth aspect, the transparent layer is formed to have substantially the same thickness as the color filter. To do.

According to a sixth aspect of the present invention, in the reflection type color liquid crystal device according to any one of the third to fifth aspects, the transparent layer contains acrylic.

According to a seventh aspect of the present invention, in the reflective color liquid crystal device according to any one of the third to fifth aspects, the transparent layer contains polyimide.

An eighth aspect of the present invention is an electronic apparatus, comprising the reflection type color liquid crystal device according to any one of the first to seventh aspects as a display section. .

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

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION The outline of the present invention will be described.
The present invention provides a pair of substrates having electrodes arranged on opposing inner surfaces to form a matrix of dot groups, a liquid crystal sandwiched between the substrates, at least two color filters, and at least one polarizing plate. It may be configured to have a reflection plate. 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, of the pair of substrates, the thickness of the substrate located on the reflecting plate side may be 200 μm or more. Further preferably, the thickness of the substrate located on the reflector side can be 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, and more preferably 4 times or more, of the shorter one of the vertical and horizontal dot pitches. With this configuration, there is an advantage that a high contrast can be secured by the parallax effect 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 30.
It is proposed that the thickness be 0 μm or less. Certainly, in the reflection type monochrome display, the lower substrate should be as thin as possible from the viewpoint of reducing double images (shadows). However, in the reflective color display, it is desired to widen the dots from the viewpoint of brightening the color display. If the distance between the dots is wide, the contrast inevitably decreases, but if the lower substrate is sufficiently thick, a high contrast can be secured by the effect of the shadow of the adjacent pixel.

At least one color filter among the color filters is 450 nm to 660 nm.
It is possible to have 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 450 nm to 660 n
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. Further, in terms of words, any color filter can have an average transmittance of 70% or more for light having a wavelength in the range of 450 nm to 660 nm. More preferably, each 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.

Incidentally, the transmittance of the color filter mentioned 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 within the dot is set as the transmittance of the color filter. With such a configuration, the reflective color liquid crystal device has an advantage that bright colors can be displayed. Conventionally, for example, in the claims of JP-A-7-239469, in any of the color filters, the transmittance of the light transmitting region is 80% or more, and the transmittance of the light absorbing region is 50%.
It is as follows. Also, looking at the example, the transmittance of the light absorption region is only 20 to 30%. In such a color filter, when 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 either the red or blue color filter may be orange or cyan. . However, the orange filter should have a wavelength of at least 570 nm to 66 nm.
70% or more, preferably 75 for light in the range of 0 nm
It may have a transmittance of at least%. Further, the cyan color filter is characterized by having a transmittance of 70% or more, and preferably 75% or more for light having a wavelength of at least 450 nm to 520 nm. With this configuration, the reflective color liquid crystal device has
It has the advantage that bright white and bright colors can be displayed.

The color filter is composed of 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 and green. It is characterized by being smaller than the minimum transmittance of the color filter of the system color filter with respect to light having a wavelength in the range of 450 nm to 660 nm. More preferably, the blue-based and green-based 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 of being able to display bright white with little coloration and also vivid red. Since red is the color stimulus most appealing to the human eye, it is very preferable to emphasize and display red.

Further, the color filter is provided only in a part of a light-modulatable region in each dot. With such a configuration, the reflective color liquid crystal device of the present invention can utilize the conventional color filter manufacturing technique and has an advantage that color mixing due to parallax can be reduced. Also, especially when the color filter is provided between the electrode and the liquid crystal, a wide viewing angle is obtained,
There is an advantage that the color purity in the halftone is improved. Conventionally, for example, Japanese Patent Publication No. 7-62723 proposes to provide a color filter on a part of a dot,
This is a transmissive liquid crystal device and is different from the present invention in that it is limited to a dyeing method color filter and the area where the color filter is provided is as large as 67% to 91% of the dot.
(Japanese Patent Publication No. 7-62723 describes 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 formed on the dot is 100/150 = 6.
From 7% to 100/110 = 91%. )

Further, a transparent layer in the visible light region is formed in a region in which the color filter is not provided in the light-modulatable region and a region in which the light-modulation is not possible, with a thickness approximately equal to that of the color filter. And With such a configuration, the reflective color liquid crystal device has an advantage that it can display a high quality image without disturbing the liquid crystal alignment.

Further, the color filter is provided only on the dots of not more than 3/4 of the total number of dots. More preferably, it is characterized in that it is provided only in two-thirds or less of the total number of dots. With such a configuration, bright display is possible, and even when performing halftone color display, there is an advantage that a bright color can always be displayed by adjusting the brightness mainly with dots without a color filter. is there. Traditionally,
In a transmissive liquid crystal device, formation of one pixel by four dots of red, green, blue, and white has been partially implemented, but it has never been proposed in a reflective liquid crystal device. Especially TN mode and STN
The problem of parallax is unavoidable in the reflective color liquid crystal device that uses the mode, and it becomes very dark when color display is performed.
By providing dots without a color filter,
Bright color display is possible.

Further, the color filters may be arranged so that the colors of adjacent dots are different. This refers to so-called mosaic arrangement or triangle arrangement, and on the contrary, stripe arrangement does not fall within this range. With such a configuration, there is an advantage that the phenomenon that the degree of coloring differs depending on the viewing angle, especially when there is parallax. Conventionally, for example, in Japanese Unexamined Patent Publication No. 8-87009, the vertical stripe arrangement is recommended in claim 6. Further, in Japanese Patent Application Laid-Open No. 5-241143, it is stated on page 6, right column, lines 17 to 18 of the specification that there is no difference in principle between the stripe arrangement and the staggered arrangement. In addition, a paper by Tatsuo Uchida et al. (IEEE Transactions
onElectron Devices, Vol.
ED-33, No. 8, pp. 1207-1211
(1986)). In No. 1, a mosaic arrangement color filter is adopted, but this is the case where the reflective electrode is provided in the 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. With this configuration, there is an advantage that the display looks bright. "Effective display area" is defined as "drive display area and effective area as subsequent screen" in ED-2511A of Japan Electronic Machinery Manufacturers Association Standard (EIAJ). Usually, in the transmissive color display, the color filter is provided only in the drive display area, and the black mask made of metal or resin is provided in the area outside the drive display area. However, in the reflective color display, the metal black mask is glaring and cannot be used. In addition, since the resin black mask does not have the black mask originally provided in the color filter, the cost increases. On the other hand, if nothing is provided outside the drive display area, the outside becomes bright and the drive display area looks relatively dark. Therefore, it is effective to provide the same color filter on the outside of the drive display area as on the inside, 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 a black mask and a color filter are not overlapped outside the dots. Further, it means that no color is provided outside the dots, but a color filter is provided partially or entirely. With this configuration, there is an advantage that a bright display can be obtained. this is,
This is because when there is parallax, the brightness of the display is proportional to almost the square of the aperture ratio, and therefore it becomes very dark if a black mask is provided. Conversely, if no color filter is provided outside the dots, the contrast becomes remarkable. This is because it will decrease.
Conventionally, for example, in JP-A-59-198489, a color filter is provided only on the pixel electrode and nothing is provided outside the color filter. Further, Japanese Patent Laid-Open No. 5-241143 describes both the case with a black mask and the case without a black mask, but there is no intermediate point.

Further, a color filter may be provided on the outer surface of the substrate located on the reflector side of the pair of substrates. With this configuration, there is an advantage that it can be provided at low cost. Further, by combining this configuration with the 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 the assembly margin is expanded and the viewing angle is widened.

Further, it is possible to provide a non-linear element corresponding to each dot on the inner surface of the substrate located on the reflector side of the pair of substrates. With this configuration, there is an advantage that unnecessary surface reflection is reduced and high contrast can be obtained.

In addition, a nonlinear element may be provided on the inner surface of one of the pair of substrates so as to correspond to each dot, and this may be connected in a direction parallel to the short side of the dot. Usually, in a data display for PC, in particular, the dots are often vertically long, and therefore the direction parallel to the short side of the dot is the horizontal direction (horizontal direction). With such a configuration, there is an advantage that the aperture ratio is increased and a bright display can be obtained. This is particularly effective when the black mask is not provided and when the reflective structure has parallax.

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

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

Further, the reflecting plate may be a semi-transmissive reflecting plate, and a backlight may be provided on the back surface thereof. Preferably, the reflector is 80% of the incident light.
The above is reflected. With this configuration, there is an advantage that it can be seen even in a dark environment.

The liquid crystal may be a nematic liquid crystal twisted by approximately 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 Japanese Examined Japanese Patent Publication Sho 51-013666
The TN mode proposed in the publication is applied to a reflective color liquid crystal device. With such a configuration, the reflective color liquid crystal device has advantages that it is bright, has high contrast, and has a wide viewing angle.

The birefringence index Δn of the liquid crystal and the liquid crystal layer thickness d
The product of Δn × d is larger than 0.34 μm and 0.52 μ
It can be smaller than m. More preferably, Δn × d can be 0.40 μm or more and 0.52 μm or less. Most preferably, Δn ×
It is possible that d is 0.42 μm. With this configuration, the reflective color liquid crystal device has
It has the advantages of being bright and having a wide viewing angle.

In the conventional reflection type monochrome liquid crystal device, the second minimum condition with less coloring, that is, Δn × d is 1.1.
The condition of about μm to 1.3 μm was used. However, in the reflective type color liquid crystal device, it is not necessary to adopt the second minimum condition because a slight coloring can be compensated by the color filter. Further, in Japanese Unexamined Patent Publication No. 8-87009, the condition of Δn × d = 0.55 μm is adopted as shown on page 5, line 27 to line 29 of the specification. However, under this condition, Δn × d is larger than 0.34 μm and smaller than 0.52 μm, and it is dark and colored.

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

Further, the reflection plate is provided between a pair of substrates,
It is possible to adopt a configuration in which only one polarizing plate is arranged. This is an application of the single-plate polarizing plate type nematic liquid crystal mode proposed in Japanese Patent Laid-Open No. 3-223715 to a reflective 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 specular reflection plate, and a scattering plate may be provided on the outer surface of the substrate located on the incident light side. By configuring in this way,
There is an advantage that a bright color with high color purity can be displayed.

Further, the liquid crystal on the metal wiring may be oriented similarly to the liquid crystal in the pixel portion. With this configuration, there is an advantage of being bright.

Further, the display can be of a normally white type. With this configuration, there is an advantage of being bright.

Also, one pixel can be constituted by one dot. With this configuration, there is an advantage that the resolution can be increased during monochrome display.

Further, the electronic apparatus of the present invention can be configured to have a reflective color liquid crystal device as a display section. With such a configuration, the electronic device has advantages of low power consumption, thin and lightweight, and good visibility even in direct sunlight.

Further, in order to efficiently reflect the ambient light to the observer, the display portion can be attached to the main body so as to be movable. With this configuration, there is an advantage that a bright display can be obtained under any lighting condition.

As can be understood from the above description, the present invention is characterized in that a liquid crystal mode using a polarizing plate is used and this is combined with a bright color filter.
There are many liquid crystal display modes using a polarizing plate, but for the purpose of the present invention, a liquid crystal display mode capable of bright and black and white display, for example, the TN mode proposed in Japanese Patent Publication No. 51-013666 and Japanese Patent Publication No. 3-502249. STN mode of retardation plate compensation type proposed in Japanese Patent Laid-Open No. 3-2237
In JP-A-15, the proposed single polarizing plate type nematic liquid crystal mode, and in JP-A-6-235920, a nematic liquid crystal mode for performing bistable switching are suitable.

In the liquid crystal mode using the polarizing plate, ½ or more of light is discarded only by the presence of the polarizing plate. Therefore, the liquid crystal mode not using a polarizing plate should be more suitable for the reflective color liquid crystal device. However, the liquid crystal mode that does not use 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 three colors of red, green, and blue, even if the green dot is in the bright state and the blue and red pixels are in the dark state to display green, the contrast is insufficient. Then, blue and red are mixed in the green display, and the color purity is lowered. However, in the liquid crystal mode using the 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 having a lower color purity. Since the color filter having low color purity is a bright color filter, the display should be brighter accordingly. Also especially PCGH
Is a normally black display, the area between dots becomes black and does not contribute to brightness, and light from the viewing angle direction other than the panel normal direction may be absorbed by the dye. Despite the lack of brightness, the brightness is about 20% higher than that of TN mode. This difference in brightness can be easily overcome depending on the color design of the color filter.

Another problem in utilizing the liquid crystal mode using a polarizing plate is the existence of parallax. When only one polarizing plate is used, it is possible to avoid this problem by forming a reflector in the cell, but it cannot escape in the TN mode or STN mode using two polarizing plates. The parallax has already been described in detail in the section “Prior Art”, but there are two problems. One is the cancellation of colors, and the other is the darkness of the color display.

The problem of color cancellation is that, if the colors of the color filter that passed through when entering and the color filter that passed through when exiting were different, they would cancel each other out and become completely dark. It means that it will be 1/3 of the case without it. Such a problem occurs 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 become pitch black even if it passes through different color filters.

Further, the problem that the color display is dark is that when displaying a certain single color, 2/3 of the whole dots are in a dark state, so that 2/3 of the light is absorbed at the time of incidence and is further emitted at the time of emission. 2/3 is absorbed and only 1/9 of the light is available. This is 1/3 the brightness when there is no parallax. To solve this, it is first necessary to increase the aperture ratio. Specifically, the black mask is not provided outside the dots, the MIM in which the metal wiring is only in one direction is used, the MIM is wired in the lateral direction, and the ST does not require the metal wiring.
I took measures such as using N. Further, by further reducing the drive area ratio, when displaying a single color, an area much smaller than about 2/3 of the whole area (for example, about 1/2) is in a dark state. In this way, bright color display is possible even with parallax. It should be noted that the means such as reducing the driving area ratio or not providing the black mask leads to a decrease in contrast, but by making the lower substrate thick, the decrease in contrast can be minimized.

An embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a diagram showing a main part of a structure of a reflective color liquid crystal device in Embodiment 1 of the present invention, in which electrodes are provided on opposing inner surfaces to form a matrix of dot groups. A pair of substrates, a liquid crystal sandwiched between the substrates, a color filter of at least two colors, and at least one
It consists of a sheet of polarizing plate and a reflector. 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, and 106.
Is a scattering reflector, a color filter 107 and a counter electrode (scanning line) 108 are provided on the counter substrate 102, and a signal line 109, a pixel electrode 110, and an MI on the element substrate 104.
The M element 111 is provided. Where 101, 102, and 104
Although 105 and 105 and 105 and 106 are drawn separately, this is for the sake of clarity of the drawing, and actually glued. The counter substrate 102 and the element substrate 104 are also widely separated, but for the same reason, there is actually only a gap of about several μm to several tens of μm.
Further, since FIG. 1 shows a main part of the reflection type color liquid crystal device, only 9 dots of 3 × 3 are shown, but in the present embodiment, the number of dots is more than that and 480 × 640. It may have 307200 dots or more.

The counter electrode 108 and the pixel electrode 110 are made of transparent ITO, and the signal line 109 is made 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 polarization axes of the upper and lower polarizing plates are orthogonal to each other. This is a general TN mode configuration. The color filter 107 is composed of two colors, 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. The horizontal axis of FIG. 2 is the wavelength of light, and the vertical axis is the transmittance. 201 indicates the spectrum of the red filter, and 202 indicates the spectrum of the cyan filter. The measurement of the spectrum is performed with the counter substrate alone using a microspectrophotometer,
100% transmission including glass substrate and transparent electrode, and overcoat and undercoat if present
Was corrected. Therefore, the spectral characteristics of the color filter alone are measured. Hereinafter, all spectral characteristics of the color filters were measured by this method. The transmittance in the present invention is also defined as the 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. Also, the average transmittance in the same wavelength range is 52 for the red filter.
%, And the cyan filter was 66%. Since it is a color filter with such a very pale color tone, it is more accurate to describe it as "pink" instead of "red", but in order to avoid confusion, it will be unified in pure color expression below.

The reflection type color liquid crystal device produced as described above has a reflectance of 24% when displaying white, a contrast ratio of 1:15, and is capable of displaying four colors of white, red, cyan and black. The display color was x = 0.39, y = 0.32, and the cyan display color was x = 0.28, y = 0.31. This is about 60% of the brightness of the conventional reflection type monochrome liquid crystal device and an equivalent contrast ratio, which is a characteristic that it can be sufficiently used under normal indoor illumination light or outdoors during the daytime.

In the wavelength range of 450 nm to 660 nm,
A reflective color liquid crystal device using a color filter that exhibits a transmittance of less than 30% even if a part of the display is dark and needs special illumination, or the white balance is out of order and white cannot be displayed. For any reason, it cannot withstand normal use.

Although the transparent electrode is provided on the color filter in the first embodiment, the color filter may be provided on the transparent electrode without any problem. Further, the MIM element is used as the active element, but this is advantageous in increasing the aperture ratio. Therefore, if the aperture ratio is the same, the effect of the present invention is not changed even if the 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 in Embodiment 2 of the present invention. The configuration of the second embodiment is similar to that of the first embodiment shown in FIG. 1, and is also provided with a color filter composed of two colors, red and cyan. In FIG. 3, the horizontal axis represents the wavelength of light and the vertical axis represents the transmittance, where 301 is the spectrum of the red filter and 302 is the spectrum of the cyan filter. The color filters of all colors have a transmittance of 50% or more in the wavelength range of 450 nm to 660 nm. The average transmittances in the same wavelength range were 71% for the red filter and 78% for the cyan filter.

This reflection type color liquid crystal device has a reflectance of 30% 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. ．
34, y = 0.32, cyan display color is x = 0.29, y
Was 0.31. This is a brightness of a little over 70% of the conventional reflection type monochrome liquid crystal device, and an equivalent contrast ratio.

As described above, when the color filter of at least one color has the transmittance of 50% or more for the light of all wavelengths in the range of 450 nm to 660 nm, the environment is almost equal to that of the conventional reflection type 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 color filter 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. To obtain the balance, the other color filter inevitably 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 thereof will be introduced later in Example 9.

(Embodiment 3) FIG. 1 is a diagram showing the essential parts of the structure of a reflective type color liquid crystal device in Embodiment 3 of the present invention. FIG. 2 is a diagram showing the spectral characteristics of the color filter. In this example, the thickness of the substrate located on the reflector side of the pair of substrates was 200 μm or more. The configuration of the third embodiment is basically the same as that of the reflective color liquid crystal device described in the first embodiment, and therefore 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 in both length and width, and the drive area ratio was 75%.

In Example 3, the thickness of the lower substrate was variously changed. FIG. 4 shows the contrast when the thickness of the element substrate 104 is changed. In FIG. 4, the horizontal axis represents the element substrate 104.
Thickness, the vertical axis represents contrast, 401 is a set of points indicating contrast with respect to the thickness of each element substrate 104 in Example 3, and 402 is each element substrate 104 in Comparative Example.
Is a set of points that show the contrast with respect to the thickness of.
When the color display is red, the display color is x = 0.3.
9, y = 0.32, cyan x = 0.28, y = 0.3.
It was around 1.

Since the drive area ratio is 75%, the contrast is 10 at maximum when the thickness of the element substrate is zero.
Only 0 / (100-75) = 4 can be taken. 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 alleviates light leakage between 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 this thickness is closely related to the dot pitch, "200 μm or more" and "70
The expression "0 μm or more" means "1.25 times or more of the shorter one of the vertical and horizontal dot pitches" and "4 times or more".
It may be expressed as.

(Embodiment 4) FIG. 5 is a diagram showing the spectral characteristics of a color filter of a reflective color liquid crystal device in Embodiment 4 of the present invention. The structure of the third embodiment is the same as that of the first embodiment shown in FIG.
It has a color filter consisting of colors. In FIG. 5, the horizontal axis represents the wavelength of light and the vertical axis represents the transmittance. 501 represents the spectrum of the red filter and 502 represents the spectrum of the cyan filter. 450 nm for color filters of both colors
Has a transmittance of 60% or more in the wavelength range from 1 to 660 nm. Further, 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 reflectance of 31% when displaying white, 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 is x = 0.30, y
Was 0.31. This is about 80% as bright as the conventional reflection type monochrome liquid crystal device and has an equivalent contrast ratio.

In this way, any color filter
Having a transmittance of 60% or more for light of all wavelengths in the range of 450 nm to 660 nm, it is a bright reflective type that can be used without trouble even if input means such as a touch key is attached to the entire surface of the liquid crystal device. A color liquid crystal device is obtained. However, if a color filter having an average transmissivity of more than 90% in the same wavelength range is used, the display color becomes extremely light and it becomes difficult to distinguish the colors.

(Embodiment 5) FIG. 6 is a diagram showing the essential parts of the structure of a reflective type color liquid crystal device in 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, and 606.
Is a scattering reflector, a color filter 607 and a counter electrode (scanning line) 608 are provided on the counter substrate 602, and a signal line 609, a pixel electrode 610, and MI on the element substrate 604.
The M element 611 is provided.

Here, 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, and has a mosaic checkered pattern. Arranged to draw a pattern. When the color filters are arranged in stripes as shown in FIG. 1, the viewing angle characteristics are extremely wide in the vertical direction, but when the viewing angle is swung in the left and right directions, the viewing angle direction in which coloring is performed and the viewing angle direction in which color disappears appear alternately. 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). It has been confirmed by experiments that such a phenomenon is considerably alleviated by arranging in a checkerboard pattern in a mosaic pattern as shown in FIG. It was also found that the color mixture is good even when the number of pixels is relatively small. This is a mosaic arrangement,
It is considered that this is because at least one of both eyes looks colored because the viewing angle direction to be colored and the viewing angle direction to be erased are mixed. The color filter had the same spectral characteristic as that of FIG. 3 of Example 2, and the brightness and the contrast ratio were about the same as those of Example 2. Further, although the example of the mosaic arrangement is given here, if the arrangement is such that adjacent dots have different colors, other arrangements such as a triangle arrangement are also effective.

(Embodiment 6) FIG. 7 is a diagram showing the spectral characteristics of color filters of a reflective type color liquid crystal device in Embodiment 6 of the present invention. The configuration of the sixth embodiment is similar to that of the fifth embodiment shown in FIG.
It has a color filter consisting of two colors, green and magenta, instead of red and cyan. The horizontal axis of FIG. 7 is the wavelength of light, the vertical axis is the transmittance, 701 is the spectrum of the green filter,
02 indicates the spectrum of the magenta filter. All color filters are 450nm to 660n
It has a transmittance of 50% or more in the wavelength range of m. The average transmittance in the same wavelength range is 76 for the green filter.
%, And the magenta filter was 78%.

This reflective color liquid crystal device has a reflectance of 31% when displaying white, 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 is x = 0.3
2, y = 0.29. This is about 80% as bright as the conventional reflection type monochrome liquid crystal device and has an equivalent contrast ratio.

As the two colors that are complementary colors to each other, a combination of blue and yellow is conceivable in addition to red and cyan, green and magenta, but one that can display a reddish color like the former two. However, it is more preferable in that it looks good.

(Embodiment 7) FIG. 8 is a diagram showing the essential parts of the structure of a reflective type color liquid crystal device in Embodiment 7 of the present invention. 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, 805
Is a lower polarizing plate, and 806 is a scattering reflector.
02, a color filter 807 and a counter electrode (scanning line) 808 are provided, and a signal line 80 is provided on the element substrate 804.
9, the pixel electrode 810, and the MIM element 811 were provided. A weak anti-glare treatment was applied on the upper polarizing plate in order to suppress glare of illumination light.

Here, the color filter 807 is composed of 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). And arranged in a mosaic pattern 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 represents the wavelength of light and the vertical axis represents 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 of any color has a transmittance of 50% or more in the wavelength range of 450 nm to 660 nm. The average transmittances in the same wavelength range were 74% for the red filter, 75% for the green filter, and 63% for the blue filter.

The reflection type color liquid crystal device produced as described above has a reflectance of 28% in white display, a contrast ratio of 1:14, full color display is possible, and red display color is x.
= 0.39, y = 0.32, the green display color is x = 0.31,
y = 0.35, blue display color is x = 0.29, y = 0.27
Met. This is about 7 times that of a conventional reflective monochrome liquid crystal device.
The brightness is relatively high, the contrast ratio is the same, and it is a characteristic that you can enjoy video images without the need for special lighting.

(Embodiment 8) FIG. 10 shows an embodiment 8 of the present invention.
FIG. 3 is a diagram showing an essential part of the structure of the reflective color liquid crystal device in FIG. In this embodiment, at least one color filter among the color filters is 450 nm to 660 nm.
It has a transmittance of 50% or more for light of all wavelengths in the range. The color filters are three colors of red, green, and blue, and either of the red or blue color filters is orange or cyan. First, the configuration will be described. Reference numeral 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 reflection plate, 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.
A pixel electrode 1009 was provided. Color filter 1
Reference numeral 010 denotes a pigment dispersion type, which is composed of 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). There is.

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, and 1101 is the spectrum of the red filter, 11
Reference numeral 02 is the spectrum of the green filter, and 1103 is the spectrum of the blue filter. All of 1101, 1102, and 1103 are light color filters, but images displayed with such color filters are light. In particular, red and blue have low visibility, so it is difficult to distinguish colors. Therefore, we used a bright color filter that transmits light in a wider wavelength range even if the color tone changes slightly.

When a red filter having a low color purity was used in place of the red filter, a very bright red color that was slightly orange was displayed. The spectrum of this filter is 1
Indicated at 111. This filter has a wavelength of at least 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 with low color purity was used in place of the blue filter, a very bright blue color that was slightly cyan was displayed. The spectrum of this filter is 111
3 shows. This filter has a wavelength of at least 450 nm
It is characterized by having a transmittance of 70% or more, and preferably 75% or more for light in the range from 1 to 520 nm. However, when such a color filter is used, white display tends to be bluish or reddish. Therefore, when the above color filter is used, it is desirable to adjust the color balance by combining it with a green filter having a 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.

Example 9 FIG. 12 shows Example 9 of the present invention.
3 is a diagram showing spectral characteristics of color filters of the reflective color liquid crystal device in FIG. The configuration of the ninth embodiment is similar to that of the seventh embodiment shown in FIG.
It has a color filter consisting of colors. The horizontal axis of FIG. 12 is the wavelength of light, 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 in the wavelength range of 450 nm to 660 nm is smaller than the minimum transmittance of blue and green color filters for light in the wavelength 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. See also red filter 4
The minimum transmittance for light having a wavelength in the range of 50 nm to 660 nm is clearly smaller than that of the blue filter and the green filter. By using such a red filter, it is possible to vividly display the red color that is most appealing to the human eye. Further, the spectrum 1203 of the blue filter is made closer to cyan for the purpose of compensating for making red deeper.
As a result, bright white with little color was displayed.

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

(Embodiment 10) FIG. 10 is a diagram showing the essential parts of the structure of a reflective type color liquid crystal device in Embodiment 10 of the present invention. The configuration will be described. 1001 is the 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 the color filter 1010 are provided, and the element substrate 1002
A signal line 1007, a MIM element 1008, and a pixel electrode 1009 are provided on the top. The color filter 1010 is of a pigment dispersion type and is composed of 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 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 spectra of the red filter, 1302 and 1312 are spectra of the green filter,
Reference numerals 1303 and 1313 indicate the spectrum of the blue filter. Also, 1301 and 1311, 1302 and I312,
The color filter materials 1303 and 1313 are the same, but their thicknesses are different, and 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.
It was 74% at that time. 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 graph 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
403 is a case of a red filter. In both cases, the thinner the color filter, the higher the average transmittance tends to be. The thickness of an ordinary pigment-dispersed color filter used in the transmissive type is about 0.8 μm, but when such a color filter is used, it may be exposed to direct sunlight outdoors or special illumination such as a spotlight. Unless it was done, the display was so dark that it could not be identified. Thickness is 0.23 μm
Below, that is, the average transmittance of any color filter is 70
In the case of more than%, the brightness which can be comfortably used was obtained in a relatively bright room with an illuminance of about 1000 lux, for example, an environment such as an office desk illuminated by a fluorescent lamp stand. If the thickness is 0.18 μm or less, that is, the average transmittance of any of the color filters is 75% or more, the illuminance of 200
It was bright enough to be used under normal room lighting such as Lux. Further, when the thickness was 0.8 μm or more, that is, when the average transmittance of any of the color filters was 90% or less, it was possible to display the color clearly. Thus, the pigment-dispersed 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 an embodiment 11 of the present invention. In this embodiment, the color filter is provided only in a part of the light-modulatable area in each dot. First, the configuration will be described. Reference numeral 1501 is an upper polarizing plate, 1502 is an element substrate, 1503 is a liquid crystal, 1504 is a counter substrate, and 15
Reference numeral 05 denotes a lower polarizing plate, 1506 denotes a scattering reflection plate, a counter electrode (scanning line) 1511 and a color filter 1510 are provided on the counter substrate 1504, and a signal line 1507, a MIM element 1508, and pixels are provided on the element substrate 1502. Electrode 1509
Was set up. The region where light modulation is possible in one dot is a region where the concave ITO on the element substrate and the strip ITO on the counter substrate overlap, and the outline of the ITO on the counter substrate is shown by a broken line. . (Refer to FIG. 20 which shows a similar outline although it does not appear to partially overlap with the color filter.)

The counter electrode 1511 and the pixel electrode 1509 are made of transparent ITO, and the signal line 1507 is made 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 nematic liquid crystal twisted by 90 degrees, and Δn × d of the liquid crystal cell is 1.3.
The liquid crystal Δn and the cell gap d were selected so as to be 4 μm. The upper and lower polarizing plates were arranged so that their absorption axes were parallel to the rubbing axis of the adjacent substrate. This is the brightest and least colored TN mode configuration. In addition, the color filters 1510 have two complementary colors, red (denoted by "R" in the figure) and cyan (denoted by "C" in the figure).
It is made of color, but 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 wavelength of light, the vertical axis is the transmittance, 1601 is the spectrum of the red filter,
02 indicates the spectrum of the cyan filter. 45
The average transmittances obtained by simply averaging the transmittances in the wavelength range of 0 nm to 660 nm were 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 the color filter is provided only partially, the average value in the light-modulatable region is called the average transmittance.

FIG. 17 shows the results obtained by varying the ratio of the area where the color filter is provided in the light-modulatable area and determining the average transmittance at that time. 1701 is the average transmittance of the dots provided with the red filter, and 1702 is the average transmittance of the dots provided with the cyan filter.

When the color filter area ratio is 100%, that is, when the color filter is provided on the entire surface, the display is so dark that it cannot be discriminated unless it is exposed to direct sunlight outdoors or special illumination such as a spotlight. . When the color filter area ratio is 45% or less, that is, when the average transmittance of all color filters is 70% or more, the environment is relatively bright in an illuminance of about 1000 lux, such as an office desk illuminated by a fluorescent lamp stand. Below, I got a comfortable brightness. Color filter area ratio is 35% or less,
That is, when the average transmissivity 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. Further, when the color filter area ratio was 15% or more, that is, when the average transmittance of any one of the color filters was 90% or less, it was possible to display red and cyan in a distinguishable manner. When the color filter area ratio was 25% or more, that is, when the average transmittance of each color filter was 90% or less, it was possible to display the color clearly. Further, no matter which color filter 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 those of the color filter used in the normal transmission type, except that a cyan color is used. It is desirable to provide such a color filter 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 eleventh embodiment, the MIM element is used as the active element, but this is slightly advantageous in increasing the aperture ratio. Therefore, if the same aperture ratio can be obtained even if the TFT element is used, the present invention can be used. There is no change in the effect of.

(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 region in each dot. The structure of the reflective type color liquid crystal device in this example is similar to that of the reflective type color liquid crystal device of the eleventh example shown in FIG. 15, but in the twelfth example, the characteristics of the color filter are different.

FIG. 18 is a diagram showing the spectral characteristics of the color filter used in Example 12. In FIG. 18, the horizontal axis represents the wavelength of light and the vertical axis represents the transmittance. 1801 represents the spectrum of the red filter and 1802 represents the spectrum of the cyan filter. The red filter had an average transmittance of 41%, and the cyan filter had an average transmittance of 62%. This level of brightness is the maximum for a color filter that can be manufactured by conventional processes without problems such as dispersibility of pigments.

FIG. 19 shows the results obtained by varying the ratio of the area where the color filter is provided in the light-modulatable region and determining the average transmittance at that time. 1901 is the average transmittance of the dots provided with the red filter, and 1902 is the average transmittance of the dots provided with the cyan filter.

When the color filter area ratio is 100%, that is, when the color filter is provided on the entire surface, the display is dark and difficult to see unless it is 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 all color filters is 70% or more, it is possible to use a relatively bright room with an illuminance of about 1000 lux, such as an office desk illuminated by a fluorescent lamp stand. Below, I got a comfortable brightness. 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. Further, when the color filter area ratio is 15% or more, that is, when the average transmittance of any one of the color filters is 90% or less, red and cyan can be displayed in a distinguishable manner. Color filter area ratio is 25%
Above, that is, the average transmittance of any color filter is 90
When it was less than%, it was possible to display the color clearly. Further, no matter which color filter was used, a high contrast ratio of 1:15 or more was obtained.

The color filter used in Example 12 is much brighter than the color filter used in the normal transmission type. It is desirable that such a color filter is 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 view showing the main part of the drawing structure of a reflective 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 region in each dot.
The configuration will be described. Reference numeral 2001 is an upper polarizing plate, 2002 is an element substrate, 2003 is a liquid crystal, 2004 is a counter substrate, and 200
Reference numeral 5 is a lower polarizing plate, and 2006 is a scattering reflection plate. A counter electrode (scanning line) 2011 and a color filter 2010 are provided on the counter substrate 2004, and a signal line 2007, a MIM element 2008, and a pixel are provided on the element substrate 2002. An electrode 2009 was provided. The region where light modulation is possible within one dot is a region where the concave ITO on the element substrate and the strip ITO on the counter substrate overlap, and the outline of the ITO on the counter substrate is shown by a broken line.

The color filter 2010 is composed of two colors, red (indicated by "R" in the figure) and cyan (indicated by "C" in the figure), which are in a complementary color relationship with each other. It was installed in the center. It is desirable to arrange each color filter so that there is no other color filter around it. By arranging in this way, it is possible to perform display with little color mixing. Because there is usually a distance of at least the thickness of the counter substrate between the color filter layer and the reflecting plate, light incident through the red filter may be emitted through the cyan filter, or The reverse causes color mixing, but the probability is reduced when the above arrangement is adopted.

(Embodiment 14) FIG. 21 is a diagram showing the essential parts of the structure of a reflective type color liquid crystal device in Embodiment 14 of the present invention. Also in this embodiment, the color filter is provided only in a part of the light-modulatable region in each dot. The configuration will be described. 2101 is an upper polarization plate, 2102 is an element substrate, 2103 is a liquid crystal, 2104 is a counter substrate, 2105.
Is a lower polarizing plate, 2106 is a scattering reflector, a counter electrode (scanning line) 2112 and a color filter 2111 are provided on the counter substrate 2104, and a signal line 2107, an MIM element 2108, a pixel electrode are provided on the element substrate 2102. 2109 is 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 in a complementary color relationship with each other, and each region can be optically modulated. It was divided into 5 areas and arranged in a checkered pattern. When the color filter is provided only on a part of the dot, the part without the color filter is white and conspicuous. However, when the color filter is divided into such small areas and arranged, there is an advantage that the colors are mixed well. Of course, the number of divisions may be two, but it is more effective to divide into three or more.

Further, the black mask 2 is provided at a position covering the scanning line.
110 (indicated by “BK” in the figure) was provided. This black mask is used when the counter substrate 2104 is arranged on the upper side and the element substrate 2102 is arranged on the lower side in FIG.
Especially, it has an antireflection effect. Instead of using the black pigment, red, cyan, or a combination thereof may be used instead.

(Embodiment 15) Also in the reflection type color liquid crystal device of Embodiment 15, the color filter is provided only in a part of the light-modulatable region in each dot. The structure of the reflection type color liquid crystal device in this example is as shown in FIG. 15, the reflection type color liquid crystal device of the twelfth embodiment, the reflection type color liquid crystal device of the thirteenth embodiment shown in FIG. 20, and the embodiment shown in FIG. This is the same as the reflective color liquid crystal device described in Example 14.

The feature is that the color filter is provided at a position between the electrode and the liquid crystal. In general, a color filter is often provided at a position between an electrode and a substrate in order to efficiently apply a voltage to liquid crystal. However, by arranging as in this example, two new effects were obtained. One is the expansion of the viewing angle, and the other is the improvement of the color purity in the halftone.

FIG. 22 is a diagram showing the voltage reflectance characteristic of the reflective type color liquid crystal device in preferred embodiment 15 of the present invention.
The horizontal axis represents the voltage effectively applied to the liquid crystal, and the vertical axis represents the reflectance normalized to 100% when no voltage is applied. 2201 is the characteristic of the region where the color filter is not provided in the light-modulatable region, and 2202 is the characteristic of the region where the color filter is provided. 2202 has a steeper voltage reflectance characteristic than 2201 due to the voltage drop due to the capacitance division. In other words, the voltage is less likely to be applied to the liquid crystal in the region provided with the color filter as compared with the region not provided. As described above, since there are two regions having different voltage levels in one pixel, the effects disclosed in Japanese Patent Application Laid-Open Nos. 2-12 and 4-348323 (generally "halftone method") are disclosed. Called)) improves the viewing angle characteristics. Further, in the halftone display state, the reflectance is always higher in the area provided with the color filter, so that the color is displayed darker.

(Embodiment 16) FIG. 23 is a diagram showing the structure of a color filter substrate of a reflective type color liquid crystal device in 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, and the area where the color filter is not provided in the light-modulatable area In the region, a layer transparent in the visible light region was formed with a thickness almost the same as that of the color filter. (A) is a front view and (b) is a sectional view. First, the configuration will be described. A rectangular area 2304 surrounded by a broken line in (a) shows one dot. 2309 is a glass substrate, 2301 is a red filter, 2303 is a green filter, 2302 is a blue filter, 2305 is a gap between dots, hatching area 2308 is acrylic, 2307 is a protective film, and 2306 is an ITO transparent electrode.

The spectral characteristics of the color filter used here are shown in FIG. In FIG. 25, the horizontal axis represents the wavelength of light, the vertical axis represents the transmittance, 2501 represents the spectrum of the blue filter, and 2502
Indicates the spectrum of the green filter, and 2503 indicates the spectrum of the red filter. However, this is a characteristic when the color filter formation area is 100%. A color filter showing such a spectral characteristic is shown by a dot 2304 in FIG.
It was formed with an area ratio of 50%. As a result, the spectral characteristics shown in FIG. 26 were obtained on the 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 indicates a blue filter spectrum, 2602 indicates a green filter spectrum, and 2603 indicates a red filter spectrum.

Further, acrylic 2308 having the same thickness as the color filter was formed on the portion where the color filter was not formed in FIG. Color filters 2301 and 230 at this time
The thicknesses of 2, 2303 and acrylic 2308 are both about 0.2 μm. Further, the acrylic transparent layer 2308 was formed also in the inter-dot gap 2305 without forming the light-shielding film (black stripe) formed between the dots used in the usual transmissive 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 the MIM (metal-insulation film-metal) active matrix substrate to form a liquid crystal device. The liquid crystal mode at this time was TN mode.

FIG. 24 is a diagram showing a main part of the structure of the reflective type color liquid crystal device in the sixteenth embodiment. 2402 is an element substrate, 2403 is a counter substrate, 2406 is an MIM element,
2407 is a display electrode of 1 dot, 2408 is a scanning line, 2
401 is an upper polarizing plate, 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 is acrylic, 2413 is a signal electrode, 2404 is a lower polarizing plate, and 2405 is an aluminum reflector.

The area ratio of the color filters within one dot is 50
In contrast, in a reflective color liquid crystal device using a substrate that is formed with only 100%, the alignment of the liquid crystal is disturbed by the step between the portion where the color filter is formed and the portion where the color filter is not formed, and contrast is 1: 8. The reflection type color liquid crystal device using the substrate formed in the unformed portion with the same thickness as the color filter was capable of displaying high quality images without disturbance of liquid crystal alignment. The contrast at this time was 1:20. FIG. 27 shows a color filter configuration in the case where the acrylic transparent layer is not formed in the portion where the color filter is not formed. (A) is a front view and (b) is a sectional view. 2707 is a glass substrate, 2701 is a partially formed red filter, 270
3 is a partially formed green filter, 2702 is a partially formed blue filter, 2706 is a protective film, and 2704 is 1
Dots and 2705 are inter-pixel gaps. As is clear from the sectional view of (b), there are irregularities on the color filter surface, and the liquid crystal orientation is disturbed in such a surface state.

In this embodiment, the color filter substrate of the present invention and the MIM substrate are combined, but a TFT substrate or TFD is used.
A (thin film diode) substrate may be used. Further, although the active matrix reflective type color liquid crystal device has been described in the present embodiment, the present invention can be applied to a simple matrix reflective type color liquid crystal device. The present invention is more effective when the unevenness of the substrate surface greatly influences the liquid crystal alignment as in the STN mode. Further, in this embodiment, the "mosaic array" is adopted as the color filter array, but in '93 latest liquid crystal process technology (press journal edition) pp. 321
The “triangle arrangement” and the “stripe arrangement” as described in 1) may be used.

(Embodiment 17) In Embodiment 17, the color filter is provided only in a part of the light-modulatable region in each dot, but the color filter is not provided in the light-modulatable region. A transparent layer in the visible light region is formed in the region and the region in which light modulation is not possible, with the same thickness as the color filter.

FIG. 28 is a diagram showing the structure of the color filter substrate of the reflective type color liquid crystal device in preferred embodiment 17 of the present invention. (A) is a front view and (b) is a sectional view. First, the configuration will be described. A rectangular area 2804 surrounded by a broken line in (a) shows one dot. Reference numeral 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 the hatched area 2806 is acrylic.

The spectral characteristics of the color filter used here are shown in FIG. 29, the horizontal axis represents the wavelength of light, the vertical axis represents the transmittance, 2901 represents the spectrum of the blue filter, and 2902.
Indicates the spectrum of the green filter, and 2903 indicates the spectrum of the red filter. However, this is a characteristic when the color filter formation area is 100%. A color filter having such a spectral characteristic was formed in one dot in FIG. 28 with an area ratio of 30%. As a result, the spectral characteristics shown in FIG. 26 were obtained on the average within one dot.

Further, acrylic 2807 having the same thickness as that of the color filter was formed on the portion where the color filter was not formed in FIG. At this time, the thickness of the color filter and the acrylic film is about 0.8 μm, and the light-shielding film (black stripe) formed between the dots, which is usually used in the transmissive color liquid crystal device, is not formed. A 2807 transparent layer was formed. Further, an alignment film for aligning the liquid crystal was formed and overlapped with the TFT substrate to form a liquid crystal device. At this time, the liquid crystal mode was a TN mode, a polarizing plate was attached to the outside of the glass substrate, and a silver reflector was placed on the side opposite to the observation surface.

The color filter has an area ratio of 30 within one dot.
In contrast, in a reflective color liquid crystal device using a substrate that is formed with only 100%, the alignment of the liquid crystal is disturbed due to the step between the portion where the color filter is formed and the portion where the color filter is not formed, and contrast is 1: 5. The reflection type color liquid crystal device using the substrate formed in the unformed portion with the same thickness as the color filter was capable of displaying high quality images 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, but an MIM substrate or TFD is used.
A substrate may be used. Further, although the active matrix reflective type color liquid crystal device has been described in the present embodiment, it can be applied to a simple matrix reflective type color liquid crystal device. ST
The present invention is more effective in the case where the unevenness of the substrate surface greatly affects the liquid crystal alignment such as N mode.

In the sixteenth and seventeenth embodiments, the three primary colors of red, green and blue were used for the color filter, but cyan 3001 and red 3002 shown in FIG. 30 and magenta 310 shown in FIG.
It is also possible to use two color filters having complementary colors such as 1 and green 3102 or yellow and blue.

(Embodiment 18) Embodiments 16 and 17
In the above, the color filter is partially formed in the substantially central portion of one dot, but it may be formed in an arrangement as shown in FIGS. 32 (a) and 32 (b). (A) is a region 320 in which the upper half or the lower half of one dot 3201 is formed with a color filter.
2 and the other half is the area 3203 where the color filter is not formed. (B) is a region 3202 in which the right half or left half of one dot 3201 has a color filter
Is formed, and the other half is an area 3203 where no color filter is formed. Also, FIG. 32 (c)
As shown in (d), one dot 3201 is divided into two or more, and a region 3202 in which a part is formed of a color filter,
The rest may be the area 3203 where the color filter is not formed. Even with the use of the color filters having such various patterns, it was possible to realize a reflective color liquid crystal device with high image quality.

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

[Table 1]

Example 20 Example 16 and Example 17
Then, acrylic was used for the transparent layer that fills the step between the color filter formation portion and the non-formation portion, but a high-quality reflective color liquid crystal device could be realized by using polyimide. Similarly, a reflective type color liquid crystal device with high image quality could be realized by using polyvinyl alcohol for the transparent layer. The results are summarized in Table 2. Both image quality and contrast are improved compared to when there is no transparent layer.

[Table 2]

In Examples 16 and 17, general aluminum reflectors and silver reflectors were used as the reflectors. G. A holographic reflector (SID'95 DIGEST, PP.176-17, announced by Chen et al.
9) can also be used.

(Embodiment 21) FIG. 33 is a drawing showing the essential parts of the structure of a reflective type color liquid crystal device in embodiment 21 of the present invention. In this embodiment, the color filters are provided only on the dots of which the number is 3/4 or less of the total number of dots.
The configuration will be described. 3301 is an upper polarization plate, 3302 is an element substrate, 3303 is a liquid crystal, 3304 is a counter substrate, 330
Reference numeral 5 is a lower polarization plate, 3306 is a scattering reflection plate, a counter electrode (scanning line) 3311 and a color filter 3310 are provided on the counter substrate 3304, and a signal line 3307, an MIM element 3308, and pixels are provided on the element substrate 3302. The electrode 3309 was provided.

The color filter 3310 is composed of two colors, red (indicated by "R" in the figure) and cyan (indicated by "C" in the figure), which are complementary colors to each other. Has no color filter. The color filter used here is the same as in Example 1, and its spectral characteristics are shown in FIG.

FIG. 34 shows the arrangement of the color filters as shown in FIG.
It is the figure shown in the form seen 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 1/3 of the dots, a cyan filter was provided for the 1/3 dots, and a color filter was not provided for the remaining 1/3 dots. In addition, (a), (b), (c), and (d) of FIG. 34 are white,
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, the dark state, and the non-hatched dots are off dots, that is, the bright state. When the display is performed in this way, in order to display the color with 2/3 dots of the whole,
A brighter display than usual is possible. Further, even when displaying a halftone in color display, there is an advantage that a vivid color can be always displayed by adjusting the brightness mainly with dots without a color filter. For example, when displaying a dark red color, 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 half-on.

Another color filter arrangement is shown in FIG.
A 1/4 dot was provided with a red filter, a 1/4 dot was provided with a cyan filter, and a remaining 1/2 dot was not provided with a color filter. Further, FIG. 35 (a)
(B), (c), and (d) show distributions of on-dots and off-dots when white, red, cyan, and black are displayed, respectively. When the display is performed in this manner, color display is performed with 3/4 of the dots of the whole, and therefore, it is possible to perform a brighter display than the color filter arrangement of FIG.

As another example, FIG. 36 shows an arrangement in which color filters of three colors of red, green and blue are used. In the figure, "R" indicates dots with a red filter, "G" indicates dots with a green filter, "B" indicates dots with a blue filter, and "W" indicates dots without a color filter. There is. Red filter for 1/6 of the whole dot, 1/6
The green filter was provided for the dots of 1), the blue filter was provided for the 1/6 dots, and the color filter was not provided for the remaining 1/2 dots. 36 (a) (b) (c)
(D) shows the distribution of on-dots and off-dots when white, red, green, and blue are displayed, respectively. When the display is performed in this manner, a bright display is possible because color display is performed with 4/6 dots of the whole.

A red filter is provided for 1/4 of the dots, a green filter is provided for the 1/4 dots, and a blue filter is provided for the 1/4 dots, and the remaining 1/4 dots are colored. 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 the dots.

(Embodiment 22) FIG. 37 is a diagram showing the outline of the structure of a reflective color liquid crystal device in Embodiment 22 of the present invention. (A) is a front view and (b) is a sectional view. In this embodiment, color filters are 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
The hatched area is a color filter, 3705 is a lower substrate, and 3706 is a polarizing plate with a reflector. The transparent electrode, the non-linear element, the signal line, the alignment film, etc. are omitted because the drawing becomes complicated. 3711 is a drive display area, 3712 is an effective display area, and 3713 is an area provided with a color filter. Although (b) is a horizontal sectional view, a vertical sectional view is also the same as (b). The terms “drive display area” and “effective display area” are used to refer to the Japan Electronic Machinery Manufacturers Association Standard (EI).
In ED-2511A of AJ), each is defined as "a region having a display function in a liquid crystal display device" and "a drive display region and a region effective as a subsequent 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 the entire liquid crystal panel area that is not hidden by the frame case.

The feature of the twenty-second embodiment lies in that the area 3713 provided with the color filter is the same as or wider than the effective display area 3712. By configuring in this way,
The reflective color liquid crystal device of the twenty-second embodiment has an advantage that the display looks bright. Normally, in transmissive color display,
The color filter is provided only in the drive display area, and the black mask made of metal or resin is provided in the area outside thereof. However, in the reflective color display, the metal black mask is glaring and cannot be used. In addition, since the resin black mask does not have the black mask originally provided in the color filter, the cost increases. On the other hand, if nothing is provided outside the drive display area, the outside becomes bright and the drive display area looks relatively dark. Therefore, it is effective to provide the same color filter on the outside of the drive display area as on the inside, preferably in the same pattern, 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 the dots, but when a black mask is provided in a reflection type color liquid crystal device, high contrast is obtained, but display is extremely dark. . In particular, in the liquid crystal mode in which parallax is unavoidable like the TN mode and the STN mode, there are 2
Since it is absorbed by the black mask once, the brightness has a property of being proportional to almost the square of the aperture ratio. Therefore, a black mask cannot be provided on the reflective color liquid crystal device, but on the contrary, if no light absorber is provided outside the dots, the contrast is significantly lowered, which is not preferable. Therefore, in Example 23 of the present invention, a black mask was not 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 the arrangement of color filters of a reflective type color liquid crystal device in preferred embodiment 23 of the present invention. As described above, in this embodiment, the black mask is not provided in the area outside each dot, but a color filter having absorption equal to or smaller than the area in the dot is provided instead. The basic configuration and the spectral characteristics of the color filter are the same as those in FIG. 6 and FIG. 3 of Example 5, but the arrangement of the color filter in the area outside the dots was elaborated. In FIG. 38, in the “laterally convex” region 3801, the counter electrode and the pixel electrode overlap,
This is a region where an electric field is applied to the liquid crystal and corresponds to the above-mentioned dot. A region 3802 diagonally hatched from the upper right to the lower left is a cyan filter, and a region 3803 hatched on the cross is a red filter.

In FIG. 38A, the red filter and the cyan filter are arranged so as to be in close contact with each other outside the dot.
Further, in (b), the filters are provided outside the dots, but they are arranged apart from each other. Further, in (c), a red filter is arranged outside the dots. In each case, the area outside the dot has a non-zero absorption that is the same as or smaller than that inside the dot, but a bright and high-contrast display can be obtained. Each characteristic has a reflectance of 30% when white is displayed in (a).
The contrast ratio was 1:15, (b) the reflectance was 33%, the contrast ratio was 1:13, and (c) was 29%, the ratio was 1:16.

(Embodiment 24) FIG. 39 is a diagram showing a color filter arrangement of a reflective 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 instead, a color filter having absorption equal to or smaller than the area in the dot is provided. The basic configuration and the spectral characteristics of the color filter are the same as those in FIG. 8 and FIG. 12 of Example 9, but the arrangement of the color filter in the area outside the dots was elaborated. In FIG. 39, the “laterally convex” region 3901 is a region where the counter electrode and the pixel electrode overlap each other and an electric field is applied to the liquid crystal, and corresponds to the dot of Example 23. A region 3902 diagonally hatched from the upper left to the lower right is a blue filter, a region 3903 diagonally hatched from the upper right to the lower left is a green filter, and a region 3904 hatched with crosses.
Is a red filter.

In FIG. 39 (a), although filters of three colors are provided outside the dots, they are arranged apart from each other. The separation distance was set in consideration of the maximum misalignment when the color filter was created. That is, FIG. 39B shows the color filter arrangement when the maximum possible misalignment occurs, but even in that case, the color filters of different colors do not overlap each other. The overlapping of the color filters is almost synonymous with the existence of the black mask, and therefore it should be avoided as much as possible. By arranging the color filters as described above, a bright and high-contrast reflection type color display was achieved.

(Embodiment 25) FIG. 40 is a drawing showing the essential parts of a reflective type color liquid crystal device in embodiment 25 of the present invention. Also in this embodiment, the black mask is not provided in the area outside each dot, but a color filter having absorption equal to or smaller than the area in the dot is provided instead. 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
Reference numeral 05 denotes a lower polarizing plate, 4006 denotes a scattering reflector, a color filter 4007 and a counter electrode (scanning line) 4008 are provided on the counter substrate 4002, and a signal line 4009, a pixel electrode 4010, and a pixel electrode 4010 are provided on the element substrate 4004. MIM element 401
1 was set. This color filter has a stripe arrangement that is common in data displays such as PCs. The spectral characteristics of the color filter are the same as in FIG. 12 of the ninth embodiment.

FIG. 41 is a diagram showing a color filter arrangement of a reflective type color liquid crystal device in preferred embodiment 25 of the present invention. In FIG. 41, a “transversely convex” region 4101 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. A region 4102 diagonally hatched from the upper left to the lower right is a blue filter, a region 4103 diagonally hatched from the upper right to the lower left is a green filter, and a region 4104 hatched with a cross is a red filter. is there.

In FIG. 41 (a), the filters of three colors are provided outside the dots, but they are arranged continuously in the upper and lower parts and separated from each other in the left and right parts. The separation distance was set in consideration of the maximum misalignment when the color filter was created.
That is, (b) of FIG. 41 shows the color filter arrangement when the maximum possible misalignment occurs, but even in that case, the color filters of different colors do not overlap each other. By arranging the color filters as described above, a bright and high-contrast reflection type color display was achieved.

(Embodiment 26) FIG. 42 is a sectional view showing an essential part of the structure of a reflection type color liquid crystal device in embodiment 26 of the invention. In this example, a color filter was provided on the outer surface of the substrate located on the reflector side of the pair of substrates.
The configuration will be described. Reference numeral 4201 denotes an upper polarizing plate, 4202 denotes an element substrate, 4203 denotes liquid crystal, 4204 denotes a counter substrate, and 420.
Reference numeral 5 denotes a lower polarizing plate, 4206 denotes a scattering reflection plate, 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 is provided. Although not shown in this sectional view, the signal line and the pixel electrode are connected via the MIM element. Further, 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 reflection plate side.

The spectral characteristic of the color filter is as shown in FIG. 12 if it is provided on the entire surface of the dot, and if it is provided on a part of the dot according to the ratio thereof, FIG. 16 or FIG.
The characteristics as shown in 8 are given.

By thus providing the color filter on the outside of the substrate, an inexpensive color filter can be used. This color filter may be separately provided on a film or the like and then bonded together. Moreover, especially by providing a color filter only on a part of the dot,
There are advantages that the assembly margin is expanded and the viewing angle is expanded.

(Twenty-Seventh Embodiment) In the twenty-seventh embodiment, 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. The feature is that on the substrates 104, 604, 804 located on the reflector side,
This is because the MIM elements 111, 611, and 811 are provided. By arranging in this way, the opposite groove formation,
That is, as compared with the case where the MIM element is provided on the substrates 102, 602 and 802, unnecessary surface reflection is reduced and high contrast is obtained. There are three reasons. One is signal line 1
09, 609, 809 and the reflection by the MIM element are partially absorbed by the color filters 107, 607, 807. The second is that the signal line itself has a structure in which metal Cr is stacked on metal Ta, and Ta is That is, Cr has a smaller reflectance. Thirdly, the reflected light is the liquid crystal layer 103,
That is, absorption due to birefringence interference occurs by passing through 603 and 803.

(Embodiment 28) In Embodiment 28, a non-linear element is provided corresponding to each dot on the inner surface of one of the pair of substrates and is connected in a direction parallel to the short side of the dot. . The entire structure of the reflective color liquid crystal device in this embodiment is similar to that of, for example, FIG. 8 of the seventh embodiment. The feature is in the wiring method of the MIM element.

FIG. 43 is a diagram showing a wiring method of MIM elements of the reflective type color liquid crystal device in the twenty-eighth embodiment. Four
Reference numeral 301 is a signal line, 4302 is an MIM element, and 4303 is a pixel electrode. Since the pixel electrodes respectively correspond to the red, green, and blue color filters of the counter substrate, the corresponding relationships are shown by “R”, “G”, and “B” on the pixel electrodes.

Each dot in FIG. 43 has a vertically long shape, and three dots arranged side by side form one square pixel. This is a common configuration for data displays for personal computers. At this time, the signal line is wired in parallel with the short side of the dot, that is, in the lateral 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 metal.

This is compared with the conventional configuration. Figure 44 shows
It is a figure which shows the wiring method of the (transmissive) color liquid crystal device using the conventional MIM element. 4401 is a signal line, 4402
Is an MIM element, and 4403 is 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 to the long sides of the dots, that is, in the vertical direction. With such wiring, the number of wirings is three times that in the case of FIG. 43 and the aperture ratio is low. The reason why such wiring has been done in the past is that one is because the vertical wiring has a shorter distance in a horizontally long panel, and the other is that if a black mask is provided, even if it is wired vertically This is because the aperture ratio does not change even if wiring is performed.

When the aperture ratio is high, the display becomes bright. The effect that the aperture ratio has on the brightness, and in particular, the remarkable effect in the reflective type structure having parallax, has been described in detail in Examples 23 to 25.

(Example 29) In Example 29, the drive area ratio is 60% or more and 85% or less. FIG. 45 shows the characteristics of the reflective color liquid crystal device in this example. The same structure as that of the second embodiment is adopted, and the drive area ratio is 50% to 100.
The relationship between the driving area ratio and the contrast, and the relationship between the driving area ratio and the reflectance when changing to% is shown. Here, the drive 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 a MIM element in a pixel. The horizontal axis represents the drive area ratio, and the vertical axis represents the contrast and reflectance. 4501 is the contrast of the present embodiment, 4502 is the contrast of the comparative example, 4503 is the reflectance at the time of cyan display of the present embodiment, and 4504 is the comparative example. This is the reflectance when displaying cyan.

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

(Embodiment 30) In the reflection type color liquid crystal device, the characteristics of the scattering reflector are brightness, contrast,
It greatly affects the viewing angle characteristics. There are various types of scattering reflectors, such as those with weak scattering properties such as mirror surfaces to those with strong scattering properties such as paper, and they are selected according to the surrounding environment. It is desirable that the material has a weak scattering property with an emphasis on contrast and contrast.

46 and 47 are diagrams showing the characteristics of the reflection plate of the reflection type color liquid crystal device in preferred embodiment 30 of the present invention. The reflecting plate has a scattering characteristic such that, when the beam light is incident on the reflecting plate, 80% or more of the light is reflected in a 30 degree cone centered on the regular reflection direction.

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

For reference, FIG. 48 shows the result of computer simulation. The horizontal axis of the figure is 30 shown in FIG.
The ratio of the light reflected in the degree cone, and the vertical axis of the figure is the brightness and contrast ratio. Assuming that the light source is perfectly scattered white light such as an integrating sphere, the light reflected in the normal direction of the substrate was calculated. As for the brightness, the brightness of the standard white board is 100.
%. As is clear from this simulation result, the larger the proportion of the light reflected in the 30-degree cone, that is, the weaker the scattering degree of the reflection plate, the brighter and higher the contrast display can be obtained. However, it has been confirmed by experiments that a reflecting plate in which more than 95% of the incident light is reflected in the 30 ° cone has a remarkably narrow viewing angle characteristic and cannot be put to practical use.

(Embodiment 31) FIG. 49 is a drawing showing the essential parts of the structure of a reflective type color liquid crystal device in embodiment 31 of the present invention. The reflector is a semi-transmissive reflector and has a backlight on its back surface. 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 semi-transmissive reflector, 4912 is a backlight,
A color filter 4907 and a counter electrode (scanning line) 4908 are provided over the counter substrate 4902, and a signal line 4909, a pixel electrode 4910, an MIM element 4 are provided over the element substrate 4904.
911 is provided. Further, the color filter has the same spectral characteristic as that of the second embodiment shown in FIG.

Since the reflectance of the semi-transmissive reflector is about 70% of that of the ordinary scattering reflector, when the backlight is used in the reflection mode without lighting, the reflectance during white display is 24%.
It becomes about%. On the other hand, in the transmissive mode with the backlight turned on, the transmissivity is about 22%, and the surface brightness is 400c.
Sufficient brightness can be obtained even 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 colors by transmission, the use of a semi-transmissive reflector increases the color purity due to reflection of ambient light even in the transmission mode. effective.

It is desirable for the semi-transmissive reflector to reflect 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 of the transmissive mode tends to result in unsatisfactory results in both transmissive display and reflective display. The transparent mode is better if you can barely see it in total darkness.
You get a good display that is easily accepted by the market.

(Example 32) In Example 32, the liquid crystal was a nematic liquid crystal twisted by about 90 degrees, and two polarizing plates were arranged so that their transmission axes were orthogonal to the rubbing directions of the adjacent substrates. The basic structure of the reflective color liquid crystal device in this embodiment and the spectral characteristics of the color filter are the same as those in FIG. 6 and FIG. 3 of the fifth embodiment. The feature is
The TN mode cell condition is optimized for the reflective color liquid crystal device.

FIG. 50 is a diagram showing the relationship of each axis of the reflective type color liquid crystal device in the thirty-second embodiment. Numeral 5021 is the left-right direction (longitudinal direction) of the liquid crystal panel, 5001 is the transmission axis direction of the upper polarizing plate, 5002 is the rubbing direction of the counter substrate located on the upper side, 5003 is 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 formed by the rubbing direction of the counter substrate and the left and right direction of the liquid crystal panel is 45 °, and the angle 501 formed by the transmission axis direction of the upper polarizing plate and the rubbing direction of the counter substrate.
2 was set to 90 °, the twist angle 5013 of the liquid crystal was set to 90 ° to the right, and the angle 5014 formed by 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 viewer side (that is, the lower side of the figure) when a voltage is applied, and in combination with the viewing angle characteristics of the TN liquid crystal, it is possible to perform display with high contrast and in which shadows are difficult to see. Further, the arrangement in which the transmission axis of the polarizing plate is orthogonal to the rubbing direction of the adjacent substrate (so-called O mode) has less color change depending on the viewing angle direction as compared with the parallel arrangement (so-called E mode), and is more preferable.

The birefringence index Δn of the liquid crystal material is 0.18.
9. By setting the cell gap to 7.1 μm, Δn × d of the liquid crystal cell was set to 1.34 μm. This is the brightest condition with a non-selection voltage applied, and there is little coloring.
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 liquid crystal birefringence Δn and the liquid crystal layer thickness d was 0.34 μm.
Larger than and smaller than 0.52 μm. The basic structure of the reflective color liquid crystal device in this embodiment is the same as that of 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 of each axis of the reflective type color liquid crystal device in preferred embodiment 33. Numeral 5021 is the left-right direction (longitudinal direction) of the liquid crystal panel, 5001 is the transmission axis direction of the upper polarizing plate, 5002 is the rubbing direction of the counter substrate located on the upper side, 5003 is 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 formed by the rubbing direction of the counter substrate and the left-right direction of the liquid crystal panel is 45 °, and the angle 5012 formed by the transmission axis direction of the upper polarizing plate and the rubbing direction of the counter substrate.
To 90 °, the liquid crystal twist angle 5013 to the right 90 °,
The angle 5014 formed by 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 viewer side (that is, the lower side of the figure) when a voltage is applied, and in combination with the viewing angle characteristics of the TN liquid crystal, it is possible to perform display with high contrast and in which shadows are difficult to see. Further, the arrangement in which the transmission axis of the polarizing plate is orthogonal to the rubbing direction of the adjacent substrate (so-called O mode) has less color change depending on the viewing angle direction as compared with the parallel arrangement (so-called E mode), and is more preferable.

Here, the birefringence Δn of the liquid crystal material is 0.08.
4, the cell gap was changed, and the panels with different Δn × d were manufactured.

FIG. 51 shows the relationship between Δn × d and the reflectance during white display. Reference numeral 5101 indicates the reflectance for each Δn × d of the example, and 5102 indicates the reflectance for each Δn × d of the comparative example. For the measurement, an integrating sphere was used so that the light was uniformly incident from all directions. The reflectance is 10 on a standard white plate.
Taken to 0%. From FIG. 51, it can be seen that the display becomes darker as the viewing angle becomes narrower and the utilization efficiency of the obliquely incident light decreases as Δn × d becomes larger. Therefore, in order to obtain a bright display, it is preferable to use the 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. Therefore, in the conventional reflection type monochrome liquid crystal device, the condition of large Δn × d as in Example 32 was used. However, in the reflective type color liquid crystal device, a little coloring can be corrected by adjusting the color filter. In Example 33, by adjusting the color filter so as to have a high transmittance on the long wavelength side, which Δn × d
However, white was almost colorless and the color was almost unchanged.

The highest reflectance is shown 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, bright display can be obtained by making Δn × d larger than 0.34 μm and smaller than 0.52 μm.

When .DELTA.n.times.d is smaller than 0.40 .mu.m, 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 appears dark under a spot light source. It is preferable that xd is 0.40 μm or more. Further, if it is 0.48 μm or less, extremely large coloring can be eliminated, and therefore Δn × d is 0.
It is preferably 48 μm or less. Most preferred Δn
Xd is 0.42 μm at which the maximum brightness is obtained.

Example 34 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. 52 is a diagram showing a main part of a reflective type color liquid crystal device in preferred embodiment 34. First, the configuration will be described. 520
1 is an upper polarizing plate, 5202 is a retardation film, 5203
Is an upper substrate, 5204 is a liquid crystal, 5205 is a lower substrate, 5
Reference numeral 206 denotes a lower polarization plate, 5207 denotes a scattering reflection plate, 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 film of polycarbonate and exhibits a positive retardation. Further, the color filter has the same spectral characteristic as that of the second embodiment shown in FIG.

FIG. 53 is a diagram showing the relationship of each axis of the reflective type color liquid crystal device in the thirty-fourth embodiment. Reference numeral 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, 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 horizontal direction of the liquid crystal panel is 30 °, the angle 5314 formed by the transmission axis direction of the upper polarizing plate and the stretching direction of the retardation film is 54 °, and the stretching of the retardation film is performed. Direction and the rubbing direction of the upper substrate have an angle 5315 of 80 °, a liquid crystal twist angle 5312 of 240 ° to the left, and an angle 5313 of the transmission axis of the lower polarizing plate and the rubbing direction of the lower substrate of 43 °. Set. When placed in this way,
The molecules at the center of the liquid crystal layer rise from the viewer side (that is, the lower side of the figure) when a voltage is applied, and in combination with the viewing angle characteristics, it is possible to perform display with high contrast and in which shadows are difficult to see.

This is a phase difference plate compensation type STN mode proposed in Japanese Patent Publication No. 3-50249, and is characterized in that multiplex driving up to a duty ratio of 1/480 can be performed with a simple matrix. Moreover, although the same color filter as that of the second embodiment is used, the signal line and the MI are used.
The aperture ratio is high due to the fact that the M element is unnecessary, and the reflectance when displaying white is 33%, which enables very bright display. The contrast ratio was 1: 8, which was relatively low, but one more retardation film for color compensation was added.
By performing the multi-line simultaneous selection drive according to the method disclosed in Japanese Patent No. 30, it is possible to display the same color with the same contrast as in the case where the MIM element is provided.

(Example 35) In Example 34 of the present invention as well,
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 showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 35. First, the configuration will be described.
5501 is an upper polarizing plate, 5502 is a retardation film, 5
503 is an upper substrate, 5504 is a liquid crystal, 5505 is a lower substrate, 5506 is a lower polarizing plate, 5507 is a scattering reflection plate, and a color filter 5508 is provided on the upper substrate 5503.
Then, the scan electrode 5509 is provided, and the signal electrode 5510 is provided on the lower substrate 5505. The retardation film 5502 is a uniaxially stretched film of polycarbonate and has a positive 587n.
It has a phase difference of m. Product of liquid crystal △ n and cell gap △
n × d is 0.85 μm.

FIG. 53 is a diagram showing the relationship of each axis of the reflective type color liquid crystal device in the thirty-fifth embodiment. Reference numeral 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, 5304 is the transmission axis of the lower polarizing plate. The direction 5305 is the stretching direction of the retardation film. The angle 5311 formed by the rubbing direction of the upper substrate and the left-right direction of the liquid crystal panel is 30 °, the angle 5314 formed by the transmission axis direction of the upper polarizing plate and the stretching direction of the retardation film is 38 °, and the retardation film is stretched. The angle 5315 formed by the vertical direction and the rubbing direction of the upper substrate is 92 °, the twist angle 5312 of the liquid crystal is 240 ° left, and the angle 5313 formed by the transmission axis direction of the lower polarizing plate and the rubbing direction of the lower substrate is 50 °. Set.

FIG. 54 shows the spectral characteristics of the color filters of the reflective type color liquid crystal device in preferred embodiment 35. In FIG. 54, the horizontal axis represents the wavelength of light and the vertical axis represents the transmittance.
Reference numeral 401 denotes a red filter spectrum, 5402 denotes a green filter spectrum, and 5403 denotes a blue filter spectrum. This color filter characteristic is optimized so that white balance can be obtained from the spectral characteristic 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 the wavelength range of 450 nm to 660 nm. Also 450nm of red filter
The minimum transmittance for light in the wavelength range from 1 to 660 nm is clearly smaller than that of the blue and green filters. By using such a red filter, it is possible to vividly display the red color that is most appealing to the human eye. Further, the spectrum 5403 of the blue filter is made closer to cyan for the purpose of compensating for making red deeper.

This is a phase difference plate compensation type STN mode proposed in Japanese Patent Publication No. 3-50249, and 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 retardation plate compensation type STN mode, although it is possible to display in black and white, only white which looks like cyan is produced. However, in the reflective type color liquid crystal device of the thirty-fifth embodiment, by optimizing the color filter, it has become possible to display white, which is much closer to neutral than in the past. In addition, although a color filter having characteristics similar to those of Example 9 was used, the aperture ratio was high because the signal line and the MIM element were unnecessary, and the reflectance during white display was 29%, which was very bright. It is possible.

(Example 36) In Example 36 of the present invention,
A reflecting plate was provided between the pair of substrates, and only one polarizing plate was arranged. FIG. 56 is a diagram showing a main part of a reflective type color liquid crystal device in preferred embodiment 36. First, the configuration will be described. 560
1 is an upper polarizing plate, 5602 is a counter substrate, 5603 is a liquid crystal, 5604 is an element substrate, and 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 a scattering reflector, MIM element 56
09 is provided. The pixel electrode also serving as the scattering / reflecting plate was one in which the surface of a sputtered film of metallic aluminum was provided with irregularities by a mechanical or chemical method. Further, the color filter has the same spectral characteristic as that of the second embodiment shown in FIG.

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

This is a single-polarizing plate type nematic liquid crystal mode proposed in Japanese Patent Application Laid-Open No. 3-223715, and since high-contrast black-and-white display can be performed without using a lower polarizing plate, it comes into contact with liquid crystal. The feature is that a scattering reflector can be provided at the position.

This reflection type color liquid crystal device has a reflectance 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 is x = 0.28, y
Was 0.32. The display has no shadow, and the viewing angle dependence is extremely small. Also, for example, the light that enters through the red filter always exits through the red filter,
Color turbidity did not occur, and bright display with high color purity was possible.

Although the MIM element is used in the above embodiment, a TFT element can be used instead. Fig. 58
FIG. 3 is a diagram showing a main part of a structure in the case where a reflective color liquid crystal device of the present invention in which a reflective plate is provided between a pair of substrates and only one polarizing plate is arranged is formed by using a TFT element. First, the configuration will be described. Reference numeral 5801 is an upper polarizing plate, 5802 is a counter substrate, 5803 is a liquid crystal, 5804 is an element substrate, a color filter 5805 and a counter electrode (common electrode) 5806 are provided on the counter substrate 5802, and a gate is provided on the element substrate 5804. Signal line 5807, source signal line 5808, T
FT element 5809, pixel electrode 581 which also functions as a scattering reflector
0 is set. In the case of the MIM element, the metal wiring only runs in the vertical direction, but in the TFT element, the metal wiring runs in the vertical direction and the horizontal direction, so that the aperture ratio decreases. Fortunately, this Example 36 does not require the lower polarizing plate. So TF
When the T element is used, it is preferable that an insulating film is provided on the layer of the element and the signal line, a reflection plate also serving as a pixel electrode is provided thereon, and the two are connected through a contact hole.

(Example 37) Example 37 is 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, and the reflection plate is a specular reflection plate and is incident. Regarding the one having a scattering plate on the outer surface of the substrate located on the light side, first, six examples of the reflection type monochrome liquid crystal device will be introduced. All 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 reflective liquid crystal device in the first example. First, the configuration will be described.
590 l 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, 59
Reference numeral 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 are
The absorption axis of No. 8 is the TN mode that coincides with the slow axis of the liquid crystal 5 at the adjacent interface. Liquid crystal 5905 thickness d and birefringence Δ
The product of n, Δn × d, is 0.48 μm.

The reflection type liquid crystal device having the above structure has a brightness of 25% and a contrast of 1:15 at the time of white display in the substrate normal direction in a room, and a white display in the direction of regular reflection of the ceiling light. Had a brightness of 45% and a contrast of 1:12. Even in the regular reflection direction, the effect of the backscattering of the scattering plate does not cause the ceiling lamp to be reflected and high contrast can be obtained. As described above, since light in the specular reflection direction can be effectively used while maintaining sufficient contrast, a very bright display can be obtained.

<Second Example> FIG. 60 shows a reflection type liquid crystal device No. 1 in the second example. 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 a reflection type liquid crystal device No. 1 in the second example. 1 to No. 3 shows the axial direction of the polarizing plate of 3 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 the rubbing direction, and 6104 is the upper polarizing plate 6.
002, the angle of the transmission axis direction 6101 with the horizontal, θ1, 6
Reference numeral 105 denotes an angle θ2 formed with the horizontal direction of the rubbing direction 6102 of the upper substrate 6003, and 6106 denotes an angle θ3 formed with the horizontal direction of the rubbing direction 6103 of the lower substrate 6007. The angle is positive in the counterclockwise direction and is shown from -180 degrees to 180 degrees.

FIG. 62 shows a reflection type liquid crystal device No. 1 in the second example. 4 to No. 6 is a sectional view of FIG. 6201 is a scattering plate, 6202 is an upper polarization plate, 6203 is a retardation plate, 62
Reference numeral 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, and 620.
9 is a specular reflector.

FIG. 63 shows a reflection type liquid crystal device No. 1 in the second example. 4 to No. 6 shows the axial direction of the polarizing plate of 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, and 6303 is the upper substrate 62.
A rubbing direction of 04, 6304 is a rubbing direction of the lower substrate 6208, an angle θ1 formed by 6305 is horizontal with the transmission axis direction 6301 of the upper polarizing plate 6202, and an angle θ2 is formed with horizontal of the rubbing direction 6303 of the upper substrate 6204 by 6306. , 6307 is the rubbing direction 6 of the lower substrate 6208.
The angle θ3, 6308 formed with the horizontal of 304 is the phase difference plate 62.
The angle θ4 is the angle θ4 with the horizontal direction of the slow axis direction 6302 of No. 03.

These angle conditions and Δn × d of the liquid crystal cell,
The values of the retardation of the retardation plate are shown in Table 4 below. △ n × in the figure
The unit of d and the phase difference is μm.

[Table 4]

These properties are shown in Table 5 below.

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

<Comparative Example of First Example and Second Example> 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.
Is a lower substrate, 6407 is a lower polarizing plate, and 6408 is a scattering reflection plate. The liquid crystal 6404 is twisted at 90 degrees in the cell as in 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 adjacent interface coincides. 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 structure, the brightness in white display in the normal direction of the substrate was 28% and the contrast was 1:15 in the room. The brightness of the white display is 62 due to the reflection of the light.
%, The contrast was 1: 2, which was not practical.

<Third Example> FIG. 65 is a diagram showing the characteristics of the scattering plate of the reflective liquid crystal device in the third example. In FIG. 65, reference numeral 6501 denotes a scattering plate, 6502 denotes incident light, and 65
Reference numeral 03 is a specular reflection light, and 6504 is a 10-degree cone centering on the specular reflection light 6503. In the scattering plate 6501 of the third example, 5% of the incident light is scattered in the 10 degree cone 6503.

[0200] The scattering plate having the above-mentioned characteristics can be obtained by the technical report EI
As described in D95-146, it was obtained by mixing particles having a refractive index different from that of the medium to form forward scattering, and providing fine irregularities on the surface to adjust the back scattering. If the scattered light is larger than 10%, the reflection of the light source becomes large and the contrast is lowered, and conversely, if it is smaller than 0.5%, the blur of the display 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.
It is twisted at 0 degree, and the absorption axes of the polarizing plates 5902 and 5908 coincide with the slow axis of the liquid crystal 5905 at the close interface.
It is N mode. Thickness d of liquid crystal 5905 and birefringence Δn
The product Δn × d is 0.48 μm.

The reflection type liquid crystal device having the above structure has a brightness of 26% and a contrast of 1:15 at the time of white display in the substrate normal direction in the room, and a white display in the direction of regular reflection 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 is applied to the structure of FIGS. 60 and 62 of the second example.

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

[Table 6] Similar to Example 1, 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
601 is a scattering plate, 6602 is an upper polarizing plate, 6603 is an upper substrate, 6604 is an upper electrode, 6605 is a liquid crystal, 660
6 is a lower side polarizing plate, 6607 is a lower side electrode and a specular reflection plate, 6
Reference numeral 608 is a lower substrate. Liquid crystal 6605 is 90 in the cell
The absorption axes of the polarizing plates 6602 and 6606 are in the TN mode in which the absorption axes of the polarizing plates 6602 and 6606 coincide with the slow axis of the liquid crystal 5 at the interface close to each other. The product of the thickness d of the liquid crystal 6605 and the birefringence Δn Δn
Xd is 0.48 μm. Aluminum was vapor-deposited on the lower electrode, and a polarizing plate was obtained by coating and orienting a liquid crystal polymer solution 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-mentioned structure has a brightness of 28% and a contrast of 1:18 in the room normal direction in the room in the room normal direction, and the 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 a reflection type liquid crystal device No. 6 in the sixth example. 1 to No. 3 is a sectional view of FIG. 6
701 is a scattering plate, 6702 is an upper polarizing plate, 6703 is an upper substrate, 6704 is an upper electrode, 6705 is a liquid crystal, and 670.
Reference numeral 6 is a lower electrode / mirror reflector, and 6707 is a lower substrate.

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

FIG. 68 shows a reflection type liquid crystal device No. 6 in the sixth example. 4 to No. 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 upper electrode, 6806 liquid crystal,
Reference numeral 6807 denotes a lower electrode / specular reflection plate, and 6808 denotes a lower substrate.

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

The conditions of the angle, Δn × d of the liquid crystal, and the retardation 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.

The characteristics of the reflection type liquid crystal display device having the above constitution are shown in Table 7 below.

[Table 7] All of them provide sufficient contrast and bright display.

Each of the above-mentioned six reflection type monochrome liquid crystal devices can be used as a reflection type color liquid crystal device by adding a color filter. Next, one example will be shown.

FIG. 69 is a drawing showing the essential portions of a reflective type color liquid crystal device in preferred embodiment 37 of the present invention. 6901
Is a scattering plate, 6902 is an upper polarizing plate, 6903 is a retardation plate, 6904 is an upper substrate, 6905 is a liquid crystal, 6906 is a lower substrate, 6907 is a counter electrode (scanning line), 6908 is a signal line, and 6909 is also a pixel electrode. A specular reflector, 6910 is an MIM element, and 6911 is a color filter. The distance between pixels is 160μ in both the directions orthogonal 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 gap 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 retardation plate 6203, and 6303 is the upper substrate 620.
4 is a rubbing direction, 6304 is a rubbing direction of the lower substrate 6208, an angle θ1 formed by 6305 is horizontal with the transmission axis direction 6301 of the upper polarizing plate 6202, and an angle θ2 formed by 6306 is horizontal with the rubbing direction 6303 of the upper substrate 6204. , 6307 is the rubbing direction 63 of the lower substrate 6208.
The angle θ3, 6308 formed with the horizontal direction of 04 is the phase difference plate 620.
3 is the 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 9 degrees, the phase difference of the phase difference plate 6903 is set to 0.31 μm, and the signal line 6908 also has a pixel electrode / specular reflection plate 690.
Alignment treatment was performed 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%.
Cyan (C in the figure) and red (R in the figure) color filters of No. 2 were used.

The reflection type liquid crystal device having the above structure has a brightness of 30% in white display in the normal direction of the substrate and a contrast of 1:15 in the room, and white display in the regular reflection direction of the ceiling light. 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.
It is a bright display with sufficient color recognition.

(Embodiment 38) Embodiment 38 is a reflection type color liquid crystal device characterized in that a reflector is provided between a pair of substrates and only one polarizing plate is arranged, or the reflector is a mirror surface. In a 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, in the reflection type color liquid crystal device, the liquid crystal on the metal wiring is oriented similarly to the liquid crystal in the pixel section. Regarding the reflective color liquid crystal device, first, two examples of the reflective monochrome liquid crystal device will be introduced. By adding a color filter to each of these,
It can be used as a reflective color liquid crystal device.

<First Example> FIG. 70 is a view showing the main parts of a reflective liquid crystal device in the first example. 7001 is a scattering plate, 7002 is an upper polarizing plate, 7003 is an upper substrate, 70
Reference numeral 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.
Reference numeral 1 is an MIM element. The liquid crystal 7004 is twisted at 90 degrees in the cell, and the absorption axes of the polarizing plates 7002 and 7006 are in the TN mode in which the slow axis of the liquid crystal 7004 at the adjacent interface is matched. The product Δn × d of the thickness d of the liquid crystal 7004 and the birefringence Δn is 0.48 μm. Example 37 is used for the scattering plate.
The same as in the third example was used.

The distance between pixels is set to 160 μm in both directions orthogonal to and parallel to the signal line, 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 and the pixel electrode is 10 μm. did.

In the reflective liquid crystal device having the above structure, the signal line 7
When the liquid crystal is arranged by rubbing the regions above the pixel 009 and the counter electrode 7008 other than the pixel portion in the same manner as the region above the pixel electrode 7010, the brightness at the time of white display in the substrate normal direction is 23 in the room. %, Contrast is 1:14
And the brightness of white display in the direction of regular reflection of the ceiling light is 43
%, The contrast was 1:11.

By the way, since the metal electrode has different wettability from ITO of the pixel electrode, it is often repelled by applying the alignment film. In such a case, that is, when the alignment processing is not performed on the signal line 7009, the brightness of white display in the substrate normal direction in the room is 19% and the contrast is 1:
14, the brightness of white display in the direction of regular reflection of the ceiling light was 40%, and the contrast was 1:11.

In each case, a high contrast and a very bright display can be obtained, but an even brighter display can be obtained by performing the orientation 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. It is the figure which showed the principal part of 3. 7101 is a scattering plate, 7102 is an upper polarization plate, 710.
3 is an upper substrate, 7104 is a liquid crystal, 7105 is a lower substrate,
7106 is a specular reflector, 7107 is a counter electrode (scanning line), 7108 is a signal line, 7109 is a pixel electrode, 711.
Reference numeral 0 is an MIM element. The distance between pixels is set to 160 μm in both directions parallel and orthogonal to the signal line, and the width of the signal line is 1
The gap between the signal line and the pixel electrode was 10 μm, and the gap between adjacent pixel electrodes was 10 μm.

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

FIG. 72 shows the reflection type liquid crystal device No. 1 in the second example. 2 and No. It is the figure which showed the principal part of 4. 720
1 is a scattering plate, 7202 is a retardation 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 specular reflector, 7208 is a counter electrode (scanning line), and 7209 is a signal. Line, 7210 is a pixel electrode,
7211 is an MIM element. The interval between pixels was set to 160 μm in both directions orthogonal to and parallel to the signal line, the width of the signal line was 10 μm, the gap between the signal line and the pixel electrode was 10 μm, and the interval between adjacent pixel electrodes and the pixel electrode was 10 μm.

FIG. 63 shows a reflection type liquid crystal device No. 1 in the second example. 4 to No. 6 shows the axial direction of the polarizing plate of 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, and 6303 is the upper substrate 62.
A rubbing direction of 04, 6304 is a rubbing direction of the lower substrate 6208, an angle θ1 formed by 6305 is horizontal with the transmission axis direction 6301 of the upper polarizing plate 6202, and an angle θ2 is formed with horizontal of the rubbing direction 6303 of the upper substrate 6204 by 6306. , 6307 is the rubbing direction 6 of the lower substrate 6208.
The angle θ3, 6308 formed with the horizontal of 304 is the phase difference plate 62.
The angle θ4 is the angle θ4 with the horizontal direction of the slow axis direction 6302 of No. 03.

The same scattering plate as used in 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 was obtained by subjecting regions other than the pixel portion to orientation processing. 3 and No. In No. 4, only the pixel portion was subjected to the alignment treatment.

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

[Table 8]

The characteristics are shown in Table 9 below.

[Table 9]

In each of the examples, a bright display with high contrast can be obtained, but a brighter display can be obtained by subjecting the area other than the pixel portion to the orientation process.

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

FIG. 59 shows a reflective liquid crystal device N of the 39th embodiment.
o. 1, No. It is sectional drawing of FIG. First, the configuration will be described. 5901 is a scattering plate, 5902 is an upper polarizing plate, and 590.
3 is an upper substrate, 5904 is an upper electrode, 5905 is a liquid crystal,
Reference numeral 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, and Reference numeral 1 is 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. Reference numeral 2 denotes the liquid crystal 5 at the interface where the absorption axes of the polarizing plate 5902 and 5908 are close to each other.
The TN mode corresponds to the slow axis of 905. Liquid crystal 59
The product of the thickness d of 05 and the birefringence Δn is Δn × d is 0.48μ
m. The same scattering plate as in the third example of Example 37 was used.

FIG. 73 is a diagram showing the voltage transmittance characteristics of the reflective liquid crystal device of the thirty-seventh embodiment. Here, 7301 is No.
7302 shows the change in transmittance with respect to the voltage of 1.
Is No. It is a state of the change of the transmittance with respect to the 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-described structure is No. 1
In the room, the brightness of white display in the substrate normal direction 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. No. 2 has a brightness of 23% in white display in the room normal direction in the room and a contrast of 1:15, and a brightness of white display in the regular reflection direction of the ceiling light is 42% and a contrast of 1:15. It was 13.

Both have sufficient contrast and a bright display, but a brighter display is obtained in the normally white mode. This is because the area outside the pixels contributes to the brightness, and also has the viewing angle characteristics that allow light incident from an oblique direction to easily pass through.

(Embodiment 40) When displaying with the reflection type color liquid crystal device in the above-mentioned Examples 1 to 39, there arises a problem which does not exist in the conventional transmission type color liquid crystal device. That is, a single dot does not sufficiently develop color, and in order to display a color, it is necessary to display the same color over a wide area to some extent. This is because the color of the color filter is light, the distance between the liquid crystal layer and the reflector is large (except for Examples 36 to 39), and the colors of adjacent dots are easily mixed.

Therefore, rather than displaying a red character on a white background, a method of displaying a black character on a white background and making a part of the background red, that is, a marker-like usage is more suitable. However, the fact that a single pixel does not sufficiently develop color also means that, conversely, a color liquid crystal device can easily perform monochrome display.

The reflective color liquid crystal device of Embodiment 40 has
It is characterized in that one pixel is composed of dots. A pixel is the smallest unit that can realize the functions required for display.
In a normal color liquid crystal device, one pixel is made up of one dot for each of red, green, and blue, for a total of three dots. Therefore, in order to display a VGA of 480 × 640 pixels, 480 × 640 × 3 dots were required. When using a two-color filter of cyan and red, 480 × 640 × 2 dots were required. However, Example 40 is a color liquid crystal device, but VGA display can be performed with 480 × 640 pixels.

The structure of the 40th embodiment is the same as that of the 5th embodiment or the like. However, the following measures should be taken when displaying. An example is shown in FIG. 74, which will be described below. Here, 16 × 48 pixels are shown. (A)
FIG. 4 is a diagram showing an array of color filters, in which red (shown by “R”) and cyan (shown by “C”) are arranged in a mosaic pattern. Further, (b) and (c) are diagrams showing the distribution of on dots and off dots. Since the on-dots are dark, they are shown by hatching. The display of (b) is turned on in the form of "LCD" ignoring the color filter array, but as described above, this reflective color liquid crystal device does not sufficiently develop color with a single dot. , "LCD" appears black on a white background. Therefore, monochrome display is possible with VGA resolution. On the other hand, the display of (c) is (b)
It turns on only the cyan dots in the background, and it appears to be displayed in red and black as "LCD". When the same color is displayed over an area of 10 dots or wider as described above, it becomes possible to display the color.

In addition to such 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 the icons on the personal computer screen have a certain amount of area, they can be displayed in color.

(Example 41) The reflection type color liquid crystal device in the above-mentioned Examples 1 to 40 was adopted as a display of an electronic apparatus.

FIG. 75 is a diagram showing an example of an electronic apparatus employing the reflective color liquid crystal device in each of Examples 1 to 40. This is the so-called PDA (Personal Di
digital assistant), which is a type of portable information terminal. Reference numeral 7501 is a reflective color liquid crystal device, and a tablet for pen input is mounted on the front surface thereof. Conventionally, a reflective monochrome liquid crystal device or a transmissive color liquid crystal device has been used as a display for a PDA. Replacing these with a reflective color liquid crystal device has the advantage of dramatically increasing the amount of information by color display compared to the former, and has the advantage of longer battery life and smaller size and weight than the latter.

FIG. 76 is a diagram showing an example of the electronic device of the forty-first embodiment, in which the display portion is attached so as to be movable with respect to the main body so that the ambient light can be efficiently reflected to the observer. This is a so-called digital still camera. Reference numeral 7601 is a reflection type color liquid crystal device, which is attached to the main body so that its angle can be changed.
Although not shown, the lens is on the back side of the reflection type color liquid crystal device mounting portion. A transmissive color liquid crystal device has been conventionally used for a display for a digital still camera. Replacing this with a reflective color liquid crystal device not only prolongs battery life and reduces size, but also dramatically improves visibility in direct sunlight. Because the transmissive color liquid crystal device has a limited brightness of the backlight, it becomes difficult to see when the surface reflection increases in direct sunlight, but the reflective color liquid crystal device becomes brighter as the ambient light becomes brighter. Is. In order to effectively use this ambient light, it is effective to mount the liquid crystal device so that the angle can be changed.

In addition to the above electronic equipment, the reflection type color liquid crystal device is a palmtop PC, a sub-notebook PC, or a notebook P.
C, handy terminal, camcorder, LCD TV,
It can be applied to various electronic devices such as game consoles, electronic organizers, mobile phones, and pagers that emphasize portability.

[Brief description of drawings]

FIG. 1 is a diagram showing a main part of a 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 showing spectral characteristics of a color filter of the reflective type color liquid crystal device in Example 1 of the present invention.

FIG. 3 is a second example 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 the element substrate is changed in the reflective color liquid crystal device according to the third embodiment of the present invention.

FIG. 5 is a diagram showing spectral characteristics of color filters of a reflective type color liquid crystal device in preferred embodiment 4 of the present invention.

FIG. 6 is a fifth example of the present invention.
FIG. 3 is a diagram showing a main part of the structure of a reflective color liquid crystal device in No. 0.

FIG. 7 is a diagram showing spectral characteristics of color filters of a reflective type color liquid crystal device in preferred embodiment 6 of the present invention.

FIG. 8 is a diagram showing a main part of a 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 showing spectral characteristics of a color filter of a reflective type color liquid crystal device in preferred embodiment 7 of the present invention.

FIG. 10 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in the embodiments 8 and 10 of the present invention.

FIG. 11 is a diagram showing spectral characteristics of color filters of a reflective type color liquid crystal device in preferred embodiment 8 of the present invention.

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

FIG. 13 is a diagram showing spectral characteristics of color filters of a reflective type color liquid crystal device in preferred embodiment 10 of the present invention.

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

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

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

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

FIG. 18 is a diagram showing spectral characteristics of color filters of reflective color liquid crystal devices in Examples 12 and 26 of the present invention.

FIG. 19 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 reflective color liquid crystal device according to a twelfth embodiment of the present invention.

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

FIG. 21 is a diagram showing a main part of the structure of a reflective type color liquid crystal device in Examples 14 and 15 of the present invention.

FIG. 22 is a diagram showing voltage reflectance characteristics of a reflective type color liquid crystal device in preferred embodiment 15 of the present invention.

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

FIG. 24 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 16 of the present invention.

FIG. 25 is a diagram showing a spectral characteristic of a color filter of a reflective type color liquid crystal device in preferred embodiment 16 of the present invention.

FIG. 26 is a diagram showing average spectral characteristics within one dot of the color filter of the reflective 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 type color liquid crystal device in a comparative example referred to in Example 16 of the present invention.

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

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

FIG. 30 is a diagram showing a spectral characteristic of a color filter of a reflective type color liquid crystal device in preferred embodiment 17 of the present invention.

FIG. 31 is a diagram showing a spectral characteristic of a color filter of a reflective type color liquid crystal device in preferred embodiment 17 of the present invention.

FIG. 32 is a diagram showing the arrangement of color filters of a reflective type color liquid crystal device in preferred embodiment 18 of the present invention.

FIG. 33 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 21 of the present invention.

FIG. 34 is a diagram showing the arrangement of color filters of a reflective type color liquid crystal device in preferred embodiment 21 of the present invention.

FIG. 35 is a diagram showing the arrangement of color filters of a reflective type color liquid crystal device in preferred embodiment 21 of the present invention.

FIG. 36 is a diagram showing the arrangement of color filters of a reflective type color liquid crystal device in preferred embodiment 21 of the present invention.

FIG. 37 is a diagram showing an outline of the structure of a reflective type color liquid crystal device in preferred embodiment 22 of the present invention.

FIG. 38 is a diagram showing the arrangement of color filters of a reflective type color liquid crystal device in preferred embodiment 23 of the present invention.

FIG. 39 is a diagram showing an arrangement of color filters of a reflective type color liquid crystal device in preferred embodiment 24 of the present invention.

FIG. 40 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 25 of the present invention.

FIG. 41 is a diagram showing an arrangement of color filters of a reflective type color liquid crystal device in preferred embodiment 25 of the present invention.

FIG. 42 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 26 of the present invention.

FIG. 43 is a diagram showing a wiring method of MIM elements of a reflective type color liquid crystal device in preferred embodiment 28 of the present invention.

FIG. 44 is a diagram showing a wiring method of MIM elements in a reflective color liquid crystal device in a comparative example referred to in Example 28 of the present invention.

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

FIG. 46 is a diagram for explaining the scattering characteristics of the reflection plate of the reflective type color liquid crystal device in preferred embodiment 30 of the present invention.

FIG. 47 is a diagram showing scattering characteristics of a reflection plate of a reflective type color liquid crystal device in preferred embodiment 30 of the present invention.

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

FIG. 49 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 31 of the present invention.

FIG. 50 is a diagram showing a relationship between axes of a reflective type color liquid crystal device in preferred embodiments 32 and 33 of the present invention.

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

FIG. 52 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 34 of the present invention.

FIG. 53 is a diagram showing a relationship between axes of a reflective type color liquid crystal device in preferred embodiments 34 and 35 of the present invention.

FIG. 54 is a diagram showing a spectral characteristic of a color filter of a reflective type color liquid crystal device in preferred embodiment 35 of the present invention.

FIG. 55 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 35 of the present invention.

FIG. 56 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 36 of the present invention.

FIG. 57 is a diagram showing a relationship between axes of a reflective type color liquid crystal device in preferred embodiment 36 of the present invention.

FIG. 58 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 36 of the present invention.

FIG. 59 is a diagram showing an essential part of the structure of a reflective type color liquid crystal device in Examples 37 and 39 of the present invention.

FIG. 60 is a diagram showing an essential part of the structure of a reflective type color liquid crystal device in preferred embodiment 37 of the present invention.

FIG. 61 is a diagram showing the relationship of each axis of the reflective type color liquid crystal device in Examples 37 and 38 of the present invention.

FIG. 62 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 37 of the present invention.

FIG. 63 is a diagram showing the relationship of each axis of the reflective type color liquid crystal device in Examples 37 and 38 of the present invention.

FIG. 64 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 37 of the present invention.

FIG. 65 is a diagram showing characteristics of a scattering plate of a reflective type color liquid crystal device in preferred embodiment 37 of the present invention.

FIG. 66 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 37 of the present invention.

FIG. 67 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 37 of the present invention.

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

FIG. 69 is a diagram showing an essential part of the structure of a reflective type color liquid crystal device in preferred embodiment 37 of the present invention.

FIG. 70 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 38 of the present invention.

FIG. 71 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 38 of the present invention.

FIG. 72 is a diagram showing a main part of a structure of a reflective type color liquid crystal device in preferred embodiment 38 of the present invention.

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

FIG. 74 is a diagram showing an example of a display method of a reflective type color liquid crystal device in preferred embodiment 40 of the present invention.

FIG. 75 is a diagram showing an example of an electronic apparatus using a reflective type color liquid crystal device in preferred embodiment 41 of the present invention.

FIG. 76 is a diagram showing an example of an electronic apparatus using a reflective type color liquid crystal device in preferred embodiment 41 of the present invention.

[Fig. 77] Fig. 77 is a diagram for describing the problem of parallax peculiar to a reflective color liquid crystal device.

FIG. 78 is a diagram showing spectral characteristics of a color filter of a conventional transmissive color liquid crystal device.

79] A paper by Tatsuo Uchida et al. (IEEE Trans
actions on Electron Device
es, Vol. ED-33, No. 8, pp. 1207
-1211 (1986)). 9 is a diagram showing the spectral characteristics of the color filter proposed in No. 8.

FIG. 80: Seiichi Mitsui's paper (SID92 DIG
EST, pp. Fi of 437-440 (1992))
g. It is a figure which shows the spectral characteristic of the color filter proposed by No. 2.

81 is a diagram showing spectral characteristics of the color filter proposed in FIGS. 2 (a), (b), and (c) of Japanese Patent Laid-Open No. 5-241143.

[Explanation of symbols]

1501, 2001, 2101, 2401, ... Upper polarizing plate, 1502, 2002, 2102, 2402 ... Element substrate, 1503, 2003, 2103 ... Liquid crystal, 1504
2004, 2104, 2403 ... Counter substrate, 1505
2005, 2105, 2404 ... Lower polarizing plate, 150
6, 2006, 2106 ... Scattering reflector, 1511, 20
11, 11212 ... Counter electrode (scanning line), 2408 ... Scanning line, 1510, 2010, 2111 ... Color filter,
1507, 2007, 2107 ... Signal line, 1508, 2
008, 2108, 2406 ... MIM element, 1509,
2009, 2109 ... Pixel electrode, 2407 ... 1-dot display electrode, 2409 ... Red color filter, 2410 ... Green color filter, 2411 ... Blue color filter, 241
2 ... acrylic, 2413 ... signal electrode, 2405 ... aluminum reflector.

Continuation of front page (31) Priority claim number Japanese Patent Application No. 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 of priority claim Japan (JP) (72) Inventor Hisashi Matsushima Suwa, Nagano Prefecture 3-5 Yamato, Ichi, Seiko Epson Corporation (56) Reference JP-A-8-286178 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02F 1/1335

Claims (9)

(57) [Claims] 1. A reflection type color liquid crystal device comprising a pair of substrates arranged to face each other and comprising a color filter and a reflector, wherein a plurality of dots formed between electrodes formed on the inner surface side of the pair of substrates. The plurality of dots has a light-modulatable region, the color filter is arranged in a part of the light-modulatable region in each of the plurality of dots, A reflective color liquid crystal device characterized in that a black mask and a color filter are not provided in a region between a plurality of dots. 2. The reflective color liquid crystal device according to claim 1, wherein the color filter is arranged so as to correspond to a substantially central portion of the dot. 3. The reflection type color liquid crystal device according to claim 1, wherein a transparent layer is arranged in a region in each of the dots where the color filter is not formed. Color liquid crystal device. 4. The reflective color liquid crystal device according to claim 1, wherein a transparent layer is arranged in a region between the plurality of dots. Color liquid crystal device. 5. The reflective color liquid crystal device according to claim 3 or 4, wherein the transparent layer is formed to have substantially the same thickness as the color filter. 6. The reflective color liquid crystal device according to claim 3, wherein the transparent layer contains acrylic. 7. The reflective color liquid crystal device according to claim 3, wherein the transparent layer contains polyimide. 8. An electronic apparatus comprising the reflective color liquid crystal device according to claim 1 as a display unit. 9. The electronic device according to claim 8, wherein the display portion of the reflective color liquid crystal device is attached so as to be movable with respect to the main body so that ambient light can be efficiently reflected to an observer. Characteristic electronic equipment.