Color liquid crystal display having color filters and light blocking layers in the periphery

A color liquid crystal display device comprising light shielding layers and color filters on the inner surface of a cell, wherein similar light shielding layers and color filters are disposed also in a peripheral region outside of a display region which is equipped with groups of striped row and column electrodes opposed mutually to form pixels for display. The respective patterns of the light shielding layers and the color filters are the same in both the display region and the peripheral region. A liquid crystal layer formed in the display device has a twist angle of 160.degree. to 300.degree. and a retardation compensator composed of a film is superposed on such layer so as to compensate the elliptical polarization. And a non-selective voltage is applied continuously to the scanning electrodes in the peripheral region so as to maintain the peripheral pixels in a light-shielded state, thereby rendering the display easier to be seen. Furthermore, due to overlaps of the color filters and the light shielding layers in both the display region and the peripheral region, the gap between the substrates is retained substantially uniform to minimize the nonuniformity of the background color.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a color liquid crystal display (LCD) 
device adapted for high density display in colors, and also to a method 
for driving such a display device. 
2. Discussion of the Background 
It is noticeable of late that the industrial attention is concentrated on 
color LCD devices of a constitution having light shielding layers and 
color filters on the inner surface thereof. 
One example of the above is known as an active matrix LCD device where an 
active matrix element such as TFT (Thin Film Transistor)or MIM 
(Metal-Insulator-Metal) used practically in a liquid crystal television 
receiver and so forth is provided for each of the pixels. 
In such active matrix LCD devices, each pixel is driven in a static or 
similar mode, so that the requirement for gap control of the liquid 
crystal layer is not exactly strict. 
However, it is difficult to realize a great dimensional increase of such 
active matrix LCD device suited generally for use in a small-sized 
portable television receiver or the like. Accordingly, there have been 
some difficulties in attaining adequate application to any large-sized 
personal computer, word processor and so forth where high-density display 
characteristics are requisite. 
Meanwhile, there may exist some cases of employing, instead of the active 
matrix device used customarily heretofore, a twisted nematic (TN) type dot 
matrix LCD device which is driven in a dynamic mode. 
Since the TN type dot matrix LCD device is so constituted that an active 
matrix element is not provided for each of the pixels, it becomes possible 
to manufacture a large-sized high density display device with facility, 
whereas a problem arises with regard to deterioration of the display 
quality. 
For example, in a display device with a capacity of 640.times.400 dots 
employed generally in a personal computer or the like, the driving duty 
factor reaches 1/200 or so to eventually bring about some disadvantages 
that the viewing angle is extremely narrow and the contrast is rendered 
very low. Consequently, there are achievable merely eight colors at most 
with R-G-B in color display, and it has been substantially impossible in 
practical use to realize a display with gray scales. 
Recently a super-twisted nematic (STN) type LCD device has been developed 
as means for realizing a high density dot matrix display by the technique 
of increasing the twist angle of liquid crystal molecules between the two 
electrodes to induce a steep voltage-transmission curve. 
According to this technique, however, the value of .DELTA.n.d, which is 
product of the birefringence .DELTA.n of the liquid crystal and the 
thickness d of the liquid crystal layer in the LCD device, is 
substantially in a range of 0.8 to 1.2 microns, and a high contrast is 
obtainable merely in the combination of specific hues alone such as 
yellowish green and dark blue, bluish purple and light yellow, and so 
forth. 
Since such a LCD device is not suited for monochromatic or black-and-white 
display as mentioned, there exists a disadvantage that multi-color or 
full-color display is impossible in combination with a micro color filter. 
Meanwhile, there is proposed an improved technique as disclosed in EP 
246842, wherein an inverse-twisted liquid crystal cell or a retardation 
film are laminated to constitute a retardation compensator on such a 
super-twisted liquid crystal cell for dot display, and the elliptical 
polarization caused in the dot-display liquid crystal cell is compensated 
by the inverse-twisted liquid crystal cell to eliminate undesired coloring 
peculiar to the STN type LCD device, thereby achieving a display similar 
to the monochromatic one. 
Due to employment of such a retardation compensator, there is obtainable a 
desired display substantially equal to a monochromatic one, hence raising 
a possibility of color display by the use of a color filter in combination 
with such a display device. 
In particular, by combining the above color filter with a light shielding 
layer and disposing them in a cell, it becomes possible to realize a color 
LCD device apparently having a high contrast without any positional 
deviation. 
However, in the STN type LCD device which utilizes birefringence with the 
liquid crystal cell having such a twist angle, even a slight variation in 
the thickness of the liquid crytal layer is visually represented as color 
due to the birefringence so that, unless the thickness of the liquid 
crystal layer corresponding to an inter-substrate gap is retained to be 
remarkably uniform, there occurs nonuniformity of the background color to 
consequently blur the display with conspicuous deterioration of the 
display quality. 
Therefore, it has been required to develop an improved color LCD device 
which is capable of ensuring high display quality while maintaining 
sufficient uniformity with facility despite any large area of the 
inter-substrate gap. 
SUMMARY OF THE INVENTION 
The present invention has been accomplished in an attempt to solve the 
problems observed in the aforementioned prior art. And its object resides 
in providing an improved color LCD device with light shielding layers and 
color filters formed on the inner surface of a cell, wherein similar light 
shielding layers and color filters are arranged also in the periphery of a 
display region where groups of electrodes are opposed to each other to 
perform visual representation. 
According to one aspect of the present invention, there is provided a color 
LCD device employing thin-film light shielding layers and thick-film color 
filters. Particularly in the display region to perform visual 
representation with electrode groups opposed to each other, color filters 
are disposed in pixel portions while light shielding layers are disposed 
between the pixels. Furthermore, in the outer periphery of the display 
region, light shielding layers similar to those disposed between the 
pixels of the display region are disposed on the entire surface of the 
peripheral region, and also there are disposed color filters which are 
structurally similar to those in the pixel portions of the display region 
and have an area corresponding to 50 to 100% of the filter area in the 
pixel portions. 
According to another aspect of the present invention, there is provided a 
color LCD device employing thick-film light shielding layers and 
thick-film color filters. In a display region to perform visual 
representation with electrode groups opposed to each other, color filters 
are disposed in pixel portions while light shielding layers are disposed 
between the pixels. And the outer periphery of the display region is 
furnished with light shielding layers and color filters equal in pattern 
to those in the display region. 
According to a further aspect of the present invention, there is provided a 
color LCD device employing thick-film light shielding layers and 
thick-film color filters. In a display region to perform visual 
representation with electrode groups opposed to each other, color filters 
are disposed in the pixel portions while light shielding layers are 
disposed between the pixels. And the outer periphery of the display region 
is entirely furnished with light shielding layers similar to those between 
the pixels in the display region, and also with color filters which are 
similar to those in the display region and have an area corresponding to 5 
to 50% of the filter area in the display region. 
In the LCD device of the present invention where color filters and light 
shielding layers are arranged on the inner surface of its substrate, the 
constitution of the color filters and the light shielding layers in the 
periphery of the display region can be changed by the thickness of the 
color filters and the light shielding layers disposed in the display 
region, hence maintaining further higher uniformity with respect to the 
thickness of the whole liquid crystal layer in the cell. 
The LCD device of the present invention is so constituted that 
fundamentally a nematic, smectic or similar liquid crystal material is 
contained in the gap between a pair of substrates aligned and furnished 
with groups of electrodes, and color filters and light shielding layers 
are arranged on the inner surface of its cell. 
More specifically, it is a dot matrix LCD device comprising striped row 
electrode groups disposed on one substrate and striped column electrode 
groups disposed on another substrate orthogonally and opposite thereto, 
and a liquid crystal material is contained and sealed between the 
substrates. 
Although the present invention may be applied to an ordinary TN type LCD 
device, greater effects are attainable by the application to an STN type 
LCD device where high uniformity is required with regard to the thickness 
of the liquid crystal layer, particularly to a monochromatic STN type LCD 
device which employs a retardation compensator to achieve a 
black-and-white display without the provision of any color filter. 
In this monochromatic STN type LCD device, there may be used a combination 
of an ordinary STN type LC cell where a layer of liquid crystal molecules 
having a twist angle of 160.degree. to 300.degree. is contained between 
electrodes-furnished substrates, with a retardation compensating LC cell 
where a layer of liquid crystal molecules having an inverse twist angle of 
a value substantially equal to the above or having an angular deviation of 
60.degree. to 120.degree. therefrom is contained between substrates, or 
with a birefringence compensator which is composed of a plate capable of 
performing birefringence compensation similarly to such a retardation 
compensator. A pair of polarizing plates are disposed outside of the 
display LC cell and the birefringence compensator. In this case, the twist 
angle, aligning direction, direction of polarizing axis and so forth may 
be adjusted properly in such a manner as to render the display similar to 
a monochromatic one. 
In the monochromatic STN type LCD device equipped with such a birefringence 
compensator, the elliptical polarized light having passed through the 
display LC cell is compensated with regard to the retardation, so that the 
display can be rendered substantially monochromatic without any color 
filter. 
In the present invention, both the color filters and the light shielding 
layers are disposed on the inner surface of the display LC cell. 
The color filter may be composed of a film having a thickness of one to 
several microns and formed by the known method of dyeing, color ink 
printing, photoeching with optosetting color ink, electrodeposition or the 
like. 
Meanwhile, the light shielding layer may be composed of either a thick film 
having a thickness of 0.8 to several microns and formed by the known 
method of black dyeing, black ink printing, photoetching with optosetting 
black ink, electrodeposition or the like; or a thin metallic film having a 
thickness less than 0.5 micron and formed by nickel plating, chromium 
deposition or the like. 
Such color filters and light shielding layers may be interposed between the 
substrate and the electrode, or between the electrode and the aligning 
film; or one may be disposed below the electrode while another above the 
electrode. 
In the present invention, such light shielding layers and color filters are 
arranged in the display region where electrode groups are mutually opposed 
to perform visual representation; and furthermore, similar light shielding 
layers and color filters are arranged in the peripheral region which is 
outside of the display region and inside of the seal. 
In the present invention, pixels are formed with electrodes opposed to each 
other. More specifically, in the aforementioned dot matrix type LCD 
device, groups of striped row electrodes and groups of striped column 
electrodes orthogonal thereto are superposed on each other to form pixels. 
In the color LCD device of the present invention where the pixel portions 
in the display region are completely covered with the color filters, the 
pattern of the color filters is so determined as to become larger than the 
pattern of the openings in the light shielding layers so that the 
periphery of each color filter overlaps the light shielding layer between 
the pixels. Consequently, in the display region, there are formed overlaps 
where the light shielding layers are superposed partially on the color 
filters. 
In case such thick-film light shielding layers are used, due to the overlap 
between the light shielding layer and the color filter, the thickness 
tends to become nonuniform despite the provision of a leveling layer 
thereon. For the purpose of reducing such nonuniformity, it is desired 
that the thickness of the light shielding layer be made smaller than that 
of the color filter. 
Meanwhile, if the light shielding layers alone are formed in the peripheral 
region, the layer thickness in the peripheral region comes to be smaller 
than that in the display region, so that it is difficult to retain the 
inter-substrate gap uniform on the entire surface of the cell. However, in 
the constitution of the present invention where the layer thickness in the 
peripheral region can be substantially equalized to that in the display 
region, the inter-substrate gap is controllable to be uniform with 
facility on the entire surface of the cell. 
The layer thickness can be rendered further uniform by providing electrodes 
in the peripheral region as well as in the display region, hence enabling 
control of the inter-substrate gap with accuracy. Since the electrodes are 
so formed as to have a low resistance, it is preferred that the above 
constitution be adopted particularly when the thickness thereof ranges 
from 100 to 400 nm. 
In case the light shielding layers are not formed on the entire surface of 
the peripheral region, it is desired that a voltage be applied to the 
peripheral electrodes in a manner to keep the peripheral pixels in a 
light-shielded state, because the inter-substrate gap control is prone to 
be inaccurate as the peripheral region is subjected to some harmful 
influence from the outside, and therefore the nonuniformity of the 
background color needs to be less conspicuous by maintaining the 
peripheral pixels in a light-shielded state. 
Although the present invention is adapted to be applied to a color LC 
optical device with color filters and light shielding layers formed 
between substrates and electrodes, it is also applicable to a device of a 
different constitution where color filters and light shielding layers are 
formed on electrodes. 
The reason is based on the fact that the provision of color filters and 
light shielding layers under the electrodes brings about a better result, 
since the display quality is deteriorated if thick color filters and light 
shielding layers are existent on the electrodes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Hereinafter the present invention will be described in detail with 
reference to the accompanying drawings. 
FIG. 1 is a plan view illustrating the patterns of light shielding layers 
and color filters in the vicinity of the boundary between a display region 
and a peripheral region in an exemplary constitution of the present 
invention applied to a color LCD device where thin-film light shielding 
layers and thick-film color filters are arranged on the inner surface of 
its cell. 
This is an enlarged view showing merely a left upper corner part of the 
whole color LCD device to make the invention better understood. In the 
actual color LCD device, a similar constitution is adopted also in each of 
its right upper corner part, left lower corner part and right lower corner 
part, and a peripheral region is formed around the display region. Such 
partial illustration is taken in each of other examples as well, with the 
left upper corner part alone shown in an enlarged view. 
In FIG. 1, there are included a display region 1 where electrode groups are 
opposed to each other to perform visual representation, color filters 3 
disposed in pixel portions 2, and light shielding layers 4 disposed 
between the pixels. Meanwhile, in a peripheral region 5 outside of the 
display region 1, light shielding layers 6 similar to those between the 
pixels in the display region 1 are disposed on the entire surface, and 
there are also disposed color filters 7 which are similar to the color 
filters 3 in the pixel portions of the display region 1 and each of the 
color filters 7 have an area corresponding to 50 to 100% of the area of 
each of the color filters 3. 
In such a color LCD device, as shown in its sectional view of FIG. 4, the 
pattern of the color filters 3 is larger than the pattern of openings in 
the light shielding layers 4 so that the pixel portions 2 in the display 
region of the substrate 8 are sufficiently covered with the color filters 
3, whereby the peripheries of the color filters 4 overlap the light 
shielding layers between the pixels. Therefore, in the display region, 
some partial overlaps are formed with regard to the color filters 3 and 
the light shielding layers 4. There are also shown a substrate 8, a 
leveling layer 9 formed on both the color filters 3 and the light 
shielding layers 4, and electrodes 10 formed on the-leveling layer 9. 
According to the present invention, there are arranged, on the entire 
surface of the peripheral region 5 outside of the display region 1, light 
shielding layers 6 similar to those between the pixels in the display 
region 1, and also color filters 7 which are similar to those in the pixel 
portions of the display region and each filter 7 has an area corresponding 
to 50 to 100% of the area of each of the color filters 3. 
Thus, in the periperal region 5 also, the light shielding layers 6 
partially overlap the color filters 7 as in the display region 1 to 
consequently facilitate control of the gap uniformity when a cell is 
constituted with spacers disposed on its inner surface. 
In such a color LCD device where thin-film light shielding layers and 
thick-film color filters are arranged on the inner surface of the cell, 
the light shielding layers are thinner than the color filters, so that the 
area of the color filters 7 in the peripheral region is equalized to 50 to 
100% of the area of the color filters 3 in the pixel portions. 
Particularly when the thickness of the light shielding layer is less than 
about 1/5 of that of the color filter, the area of the color filters 7 in 
the peripheral region may be the same as that of the color filters 3 in 
the pixel portions, whereby the mask, printing plate or the like used for 
forming the color filters in the display region can be utilized also for 
those in the peripheral region, so that only one kind of such mask or the 
like is needed to consequently enhance the productivity. 
Although there are illustrated merely a small number of pixels in the 
display region, a necessary number of pixels may be provided in accordance 
with individual requirements, as 1920.times.400 dots or 1920.times.480 
dots, for example. 
In the peripheral region also, there are illustrated merely one pixel on 
the upper side and three pixels on the left side (or one set of three 
colors). However, the number of pixels in the peripheral region may be 
determined adequately in conformity with the width of the peripheral 
region. Practically, since the peripheral region has a width of several to 
twenty-and-odd millimeters or so, the number of pixels may be in a range 
of several to several tens. 
It is preferred that electrodes be provided in the portions corresponding 
to pixels in the peripheral region similarly to those in the display 
region, whereby the thickness difference between the display region and 
the peripheral region is further reduced to obtain a better result. 
The contrivances mentioned above conform to the following embodiments as 
well. 
FIG. 2 is a plan view illustrating the patterns of light shielding layers 
and color filters in the vicinity of the boundary between a display region 
and a peripheral region in another example of applying the present 
invention to a color LCD device where thick-film light shielding layers 
and thick-film color filters are arranged on the inner surface of its 
cell. 
In a display region 11 where electrode groups are opposed to each other to 
perform visual representation, color filters 13 are disposed in pixel 
portions 12, and also light shielding layers 14 are disposed between the 
pixels. Furthermore, light shielding layers 16 and color filters 17 equal 
in pattern respectively to those in the display region 11 are provided in 
a peripheral region 15 outside of the display region 11. 
In this constitution also, similarly to the embodiment of FIG. 1, the 
pattern of the color filters 13 is larger than the pattern of openings in 
the light shielding layers 14 so that the pixel portions 12 in the display 
region are sufficiently covered with color filters 13, whereby the 
peripheries of the color filters 13 overlap the light shielding layers 
between the pixels. Consequently, in the display region, some partial 
overlaps are formed with regard to the color filters 13 and the light 
shielding layers 14. 
According to the present invention, there are formed, in the peripheral 
region 15 outside of the display region, light shielding layers 16 and 
color filters 17 which are similar in pattern respectively to the light 
shielding layers 14 and the color filters 13 in the pixel portions of the 
display region. 
As a result, the peripheral region is also furnished with the color filters 
17 and the light shielding layers 16 in the same manner as in the display 
region, so that if both the light shielding layers and the color filters 
are composed of thick films and are partially overlapped, the display 
region and the peripheral region come to have the same constitution, 
thereby facilitating control of the gap uniformity when a cell is produced 
with spacers disposed on its inner surface. 
In this case also, the patterns of the color filters 17 and the light 
shielding layers 16 in the peripheral region may be the same as those of 
the color filters 13 in the pixel portions and the light shielding layers 
14, whereby the mask, printing plate or the like used for forming the 
color filters can be utilized for both the display region and the 
peripheral region, so that only one kind of such mask or the like is 
needed to consequently enhance the productivity. 
In this example, it is desired that electrodes be provided also in the 
peripheral region, and a voltage be applied thereto in such a manner as to 
maintain the peripheral pixels in a light-shielded state. Since the 
peripheral region is harmfully affected from its outside such as the 
sealed portion and so forth, the inter-substrate gap control is prone to 
become inaccurate. However, the nonuniformity of the background color can 
be rendered less conspicuous by maintaining the peripheral pixels in a 
light-shielded state as mentioned above. 
In this case, the requirement is satisfied if the electrodes in the 
peripheral region are driven simultaneously while the electrodes in the 
display region are normally so disposed as to be drivable for individual 
pixels. Therefore, the pattern of the peripheral electrodes may be the 
same as that in the display region or may be wider than that as well. More 
specifically, in the embodiment of FIG. 2, three electrodes serving 
originally for R-G-B three colors may be shaped into a single electrode of 
a triple width substantially. In the embodiment of FIG. 2, each segment of 
the vertical peripheral region consists of one pixel, while each segment 
of the horizontal peripheral region consists of three pixels. However, in 
one ordinary color LCD device, the number of such pixels is mostly in a 
range of 10 to 100, and they may be formed by one or more electrodes. 
The electrodes in the peripheral region are connected to a driving circuit, 
and a voltage is applied thereto in such a manner that the pixels in the 
peripheral region are driven to be kept in a light-shielded state. When 
the LCD device has a positive type constitution, a multiplex-driving 
selective voltage may be applied to the pixels in the peripheral region. 
Meanwhile, in case the LCD device is a negative type, a multiplex-driving 
non-selective voltage may be applied to the pixel portions in the 
peripheral region. Since application of such selective voltage or 
non-selective voltage can be effected with facility from an ordinary 
multiplex driving circuit, there exists no necessity of providing any 
additional circuit, so that an advantage is attained in manufacture of a 
module. It is also possible to apply a higher voltage to the pixels in the 
peripheral region by incorporating another circuit individually. 
FIG. 3 is a plan view illustrating the patterns of light shielding layers 
and color filters in the vicinity of the boundary between a display region 
and a peripheral region in a further example of applying the present 
invention to a color LCD device where thick-film light shielding layers 
and thick-film color filters are arranged on the inner surface of its 
cell. 
In a display region 21 where electrode groups are opposed to each other to 
perform visual representation, color filters 23 are disposed in pixel 
portions 22, and also light shielding layers 24 are disposed between 
pixels. Meanwhile in a peripheral region 25 outside of the display region, 
there are disposed light shielding layers 26 similar to those between the 
pixels in the display region, and also color filters 27 which are similar 
to those in the pixel portions of the display region and have an area 
corresponding to 5 to 50% of the area of each of the color filters 23 in 
the display region. 
In this constitution also, similarly to the embodiment of FIG. 1, the 
pattern of the color filters 23 is larger than the pattern of openings in 
the light shielding layers 24 so that the pixel portions 22 in the display 
region are sufficiently covered with the color filters 23, whereby the 
peripheries of the color filters 21 overlap the light shielding layers 
between the pixels. Consequently, in the display region, some overlaps are 
formed with regard to the color filters 23 and the light shielding layers 
24. 
According to the present invention, there are formed, on the entire surface 
of the peripheral region 25 outside of the display region, light shielding 
layers 26 similar to those between the pixels in the display region, and 
also color filters 27 which are similar to those in the pixel portions of 
the display region and have an area corresponding to 5 to 50% of the area 
of each of the aforementoined color filters 23 in the display region. 
In this embodiment where both the color filters and the light shielding 
layers are composed of thick films, if the color filters 27 and the light 
shielding layers 26 in the peripheral region are so formed as to mutually 
overlap, as in the embodiment of FIG. 1, with the patterns similar to 
those in the display region, then the resultant film thickness becomes 
considerably great to eventually bring about difficulty in maintaining the 
desired uniformity of the inter-substrate gap in the entire display 
region. 
In view of such circumstances, as mentioned above, the area of the color 
filters 27 overlapped with the light shielding layers in the peripheral 
region is reduced to 5 to 50% of the area of each of the color filters 23 
in the pixel portions of the display region, whereby the above 
disadvantage is diminished and therefore control of the gap uniformity can 
be facilitated when a cell is produced with spacers disposed on the inner 
surface of the cell. 
Thus, the color filters in the peripheral region may be so arranged as to 
have the same pattern in a condition where the pixels are arrayed 
similarly in the peripheral region as well. As described above, when the 
pattern of the color filters in the peripheral region is the same as that 
of the color filters in the display region, the mask, printing plate or 
the like used for the color filters in the display region can be utilized 
also for those in the peripheral region, hence ensuring enhanced 
productivity. 
When the color filter area in the peripheral region is changed to be 
different from the color filter area in the display region, the pixels in 
the peripheral region may be arranged with the same pitch as that of the 
pixels in the display region on condition that the pixel arrangement in 
the peripheral region is the same as in the display region. Meanwhile, in 
the embodiment of FIG. 3 where the color filter area in the periperal 
region is smaller, the color filters may be formed with a pitch wider than 
that of the pixels in the display region. 
The present invention is adapted to be applied to an STN type LCD device or 
SSF (surface-stabilized ferro-electric) LCD device where extremely strict 
control of the inter-substrate gap uniformity is requisite and 
monochromatic display can be effected without using any color filter. 
In the present invention, the substrates constituting a liquid crystal cell 
may be optically isotropic ones and are composed usually of transparent 
glass, plastic or like material. 
Electrodes are formed on such substrates, and a voltage is selectively 
applied between desired electrodes to drive the liquid crystal for 
display. The electrodes are composed usually of transparent material such 
as ITO (In.sub.2 O.sub.3 -SnO.sub.2), SnO.sub.2 or the like, and 
low-resistance leads of Al, Cr or Ti may be combined therewith in 
accordance with the individual requirements. And a desired patterning 
process is executed. A typical one is a dot matrix LCD device where a 
multiplicity of row and column electrode groups are existent. For example, 
striped 1920 electrodes are formed on one substrate while striped 400 
electrodes are formed orthogonally thereto on another substrate, whereby a 
display capacity of 1920.times.400 dots is obtained. 
In case electrodes are to be disposed in the peripheral region also, for 
example, striped 2040 electrodes are formed on one substrate while striped 
440 electrodes are formed on another substrate to provide 2040.times.440 
dots. In the exemplary constitution of FIG. 2, a voltage is applied to the 
120 left and right electrodes in the peripheral region and also to the 40 
upper and lower electrodes therein in such a manner that the relevant 
pixels are kept in a light-shielded state, thereby reducing the 
nonuniformity of the background color in the peripheral region to 
consequently enhance the display quality. In the case of a negative type 
LCD device employing back light, a non-selective voltage may be applied to 
its peripheral region. More specifically, a non-selective voltage is 
applied continuously to the 20 electrodes in each of the upper and lower 
peripheral regions out of the striped 440 electrodes to be sequentially 
scanned, and peripheral regions. Accordingly, the electrodes in any 
peripheral region are not selected and therefore retained in a 
light-shielded state regardless of whether the other electrodes are 
selected or not. 
Any of the known rubbing, oblique evaporation and other methods may be 
utilized for aligning the liquid crystal molecules. And the aligning 
treatment may be executed after the electrodes are coated with a film of 
inorganic material such as SiO.sub.2, TiO.sub.2 or Al.sub.2 O.sub.3 and/or 
a film of organic material such as polyimide or polyamide in conformity 
with the individual requirements. 
Any suitable ones of the known LCD elements may be employed for the spacer, 
sealing material, polarizing plate, reflecting plate, illumination means, 
driving circuit and so forth. 
Besides the above, a variety of techniques utilized for the ordinary LCD 
devices are available within the scope not impairing the effects of the 
present invention. 
The color LCD device of the present invention is adapted for use in 
personal computers, word processors and work stations as well as in any of 
various color display apparatus as such as liquid crystal television 
receivers, fish finders, radars, oscilloscopes and dot matrix display 
units. 
In the present invention, color filters and light shielding layers 
partially overlap each other in both the display region and the peripheral 
region, so that when a cell is produced with spacers disposed on its inner 
surface, the inter-substrate gap can be maintained substantially uniform 
in each of the display and peripheral regions, hence attaining 
satisfactory uniformity in the gap between the substrates throughout the 
cell. 
That is, in the constitution where the color filters and the light 
shielding layers partially overlap each other, it follows that, when 
spacers are disposed on the inner surface of the cell, the spacers are 
partially distributed in such overlaps as well, which then serve to 
thicken the inter-substrate gap. 
Consequently, if the light shielding layers alone are disposed in the 
peripheral region, there are formed, in the display region, some portions 
which are partially higher than the peripheral region due to the mutual 
overlaps of the color filters and the light shielding layers, so that the 
inter-substrate gap in the display region becomes wider than that in the 
peripheral region to eventually form portions where the inter-substrate 
gap is gradually varied in the vicinity of the boundary between the 
display region and the peripheral region, whereby nonuniformity of the 
background color is prone to occur. 
According to the present invention, the display region is also furnished 
with color filters and light shielding layers which are similar to those 
in the display region or have some adequate dimensions within a 
predetermined range. Thus, mutual overlaps of the color filters and the 
light shielding layers having substantially the same area as in the 
display region are formed also in the peripheral region, so that when 
spacers are disposed, the inter-substrate gap in the peripheral region is 
rendered substantially uniform and equal to that in the display region. 
In this case, the inter-substrate gap can be controlled with a higher 
accuracy by the provision of electrodes in the peripheral region as well. 
Consequently there are formed, in the peripheral region also, mutual 
overlaps of the color filters, the light shielding layers and the 
electrodes having substantially the same area as that in the display 
region, so that any variation caused in the inter-substrate gap with the 
disposal of spacers is suppressed in the vicinity of the boundary between 
the peripheral region and the display region, whereby the inter-substrate 
gap is rendered substantially uniform even in the outermost portion of the 
display region to eventually avert nonuniformity of the background color. 
Particularly in the constitution of FIG. 2 where the peripheral region is 
furnished with the frame-shaped light shielding layers and the color 
filters for the pixels in the same manner as the display region, it is 
preferred that a voltage be so applied as to keep the peripheral pixels in 
a light-shielded state, hence achieving enhanced control of the 
inter-substrate gap in the display region. Furthermore, although the 
uniformity of the inter-substrate gap in the peripheral region becomes 
lower than that in the display region, such is hardly recognized as the 
nonuniformity of the background color since the peripheral region is so 
driven as to be retained in a light-shielded state, whereby the display 
quality is further improved as a result. Besides the above, the display is 
rendered easier to be seen as the peripheral region is placed in a 
light-shielded state similarly to the light-shielded pixels in the display 
region. 
Since all the pixels in the peripheral region are retained in a 
light-shielded state, the peripheral electrodes may be shaped into striped 
ones similar to those for the pixels in the display region, or a plurality 
of electrodes may be grouped together to form a single electrode. However, 
it is preferred that the peripheral electrodes be exactly in conformity 
with those in the display region. 
Hereinafter some examples of the present invention will be described in 
detail with reference to the accompanying drawings. PG,29 
EXAMPLE 1 
As illustrated in FIGS. 1 and 4, thin-film light shielding layers of 
chromium were formed to a thickness of 100 nm on a glass substrate, and 
thick-film color filters (1056.times.272 dots) were formed by R-G-B three 
color dyeing process to a thickness of 2.0 .mu.m on electrode portions 
corresponding to pixels, in such a manner that the peripheries of the 
color filters were overlapped with the light shielding layers. And further 
an overcoat film (leveling layer) of polyimide was formed thereon. 
As mentioned, the surface leveling was executed by forming the overcoat 
film of polyimide on the color filters and the light shielding layers, but 
is was difficult to attain complete flatness of the surface. However, fine 
irregularities on the color filters were mostly leveled due to the 
existence of such overcoat film, and some large irregularities resulting 
from mutual overlaps of the color filters and the light shielding layers 
in the peripheries of the pixels were considerably eliminated in 
comparison with the conventional example using no such overcoat film. 
Thereafter such leveled surface was coated with ITO (In.sub.2 O.sub.3 
-SnO.sub.2) and then patterned to form striped 960 column electrodes, and 
further an insulator film of SiO.sub.2 -TiO.sub.2 was formed on the entire 
surface to a thickness of 100 nm. Subsequently a layer of polyimide was 
deposited thereon to a thickness of 70 nm or so, and rubbing was executed 
to form an aligning film, thereby constituting a column-electrode 
substrate. 
Meanwhile, striped 240 row electrodes were formed on another glass 
substrate orthogonally to the column electrodes, and an insulator film of 
SiO.sub.2 -TiO.sub.2 was formed to a thickness of 300 nm on the entire 
surface. Then, a layer of polyimide was deposited thereon to a thickness 
of 70 nm or so, and a rubbing process was executed to form an aligning 
film, thereby constituting a row-electrode substrate in such a manner that 
liquid crystal molecules have a twist angle of 240.degree. at the time of 
completion of a cell by combining the row-electrode substrate with the 
aforementioned column-electrode substrate. 
In such two substrates, striped electrodes similar to those in the display 
region were formed also in the peripheral region surrounding the display 
region. 
The column-electrode substrate and the row-electrode substrate were so 
arranged that the twist angle of liquid crystal molecules was 240.degree., 
and a cell was constituted by sealing up the peripheries of the 
substrates. And a dot matrix LC cell was produced with a supply of nematic 
liquid crystal material therein. 
A layer of polyimide was deposited to a thickness of 70 nm on a glass 
substrate, and it was processed by rubbing to form an aligning film. Two 
of such substrates were so arranged that liquid crystal molecules have a 
twist angle of 240.degree. in the reverse direction with respect to the 
dot matrix LC cell and, after sealing at the peripheries, nematic liquid 
crystal material was poured therein to produce an LC cell for retardation 
compensation. 
The dot matrix LC cell was superposed on such retardation compensating LC 
cell to constitute a laminated structure, and a pair of polarizing plates 
were disposed on the two sides thereof to manufacture a negative type LCD 
device. 
In the LCD device thus obtained, each of the display region and the 
peripheral region was furnished with the color filters and the light 
shielding layers having the same pattern (same area) respectively, so that 
the gap between the substrates was rendered substantially uniform in both 
the display region and the peripheral region, hence ensuring a visually 
satisfactory color display. 
It is to be noted that even if the LCD device of such constitution is 
modified into a positive display type with adequate adjustment of the 
relationship among the refringence anisotropy (.DELTA.n) of the liquid 
crystal material, the aligning direction and the axis of polarization 
thereof, since any region other than the pixel portion is covered with the 
light shielding layer, it is still usable as a negative type LCD device 
when driven by the application of a voltage to desired segments to be 
darkened, in a manner contrary to driving the ordinary negative type LCD 
device. 
Therefore, this LCD device is usable apparently for negative type display 
regardless of whether it is produced as a negative type or positive type 
structurally. 
COMATIVE EXAMPLE 1 
In a conventional LCD device having the same constitution as that of 
Example 1 with the exception that no color filter was provided on any 
light shielding layer in the peripheral region, the contrast was reduced 
in the shape of a frame with a width of about 5 mm inside the edge of the 
display region, and the display quality was deteriorated. 
EXAMPLES 2 and 3 
Modified color LCD devices were manufactured by changing the area of the 
color filters on the light shielding layer in the peripheral region of 
Example 1 to 80% (in Example 2) and 60% (in Example 3), respectively. 
In each of Examples 2 and 3, the inter-substrate gap was substantially 
uniform in both the display region and the peripheral region, and a 
visually satisfactory color display was attained. However, in Example 3, 
the uniformity of the inter-substrate gap was slightly lower than that in 
Examples 1 or 2. 
EXAMPLE 4 
Light shielding layers having a thickness of about 1.2 .mu.m were formed by 
a dyeing process in place of the light shielding layers used in Example 1, 
and also color filters having a thickness of about 1.8 .mu.m were formed 
by a dyeing process, and they were arranged as illustrated in FIG. 2. 
In this negative type LCD device where each of the display region and the 
peripheral region was furnished with the color filters and the light 
shielding layers having the same pattern (same area) respectively, the gap 
between the substrates was rendered substantially uniform in both the 
display region and the peripheral region, thereby achieving visually 
satisfactory display. 
EXAMPLE 5 
Light shielding layers similar to those used in Example 4 were formed on 
the entire surface of the peripheral region as illustrated in FIG. 3, and 
also color filters similar to those in Example 4 were formed partially (in 
the area corresponding to about 15% of the color filters in the display 
region). 
In this negative type LCD device where the color filters were formed 
partially on the light shielding layers in the peripheral region, the 
inter-substrate gap was substantially uniform in both the display region 
and the peripheral region to consequently realize a visually satisfactory 
display. 
In the LCD device of such constitution where any portions other than the 
pixel portions are covered with the light shielding layers similarly to 
Example 1, it is usable apparently as a negative type LCD device 
regardless of whether it is produced structurally as a negative type or 
positive type. 
EXAMPLE 6 
A glass substrate was coated with ITO and then patterned as illustrated in 
FIG. 1 to form striped 960 column electrodes, and an insulator film of 
SiO.sub.2 -TiO.sub.2 was formed to a thickness of 300 nm on the entire 
surface. Further thin-film light shielding layers of chromium were fromed 
thereon to a thickness of 100 nm, and thereafter color filters were formed 
by R-G-B three color dyeing process to a thickness of 2.0 .mu.m. 
Subsequently a layer of polyimide was deposited thereon to a thickness of 
70 nm or so, and it was processed by rubbing to form an aligning layer, 
thereby constituting a column-electrode substrate. 
Meanwhile, striped 240 row electrodes were formed on another glass 
substrate orthogonally to the column electrodes, and an insulator film of 
SiO.sub.2 -TiO.sub.2 was formed to a thickness of 300 nm on the entire 
surface. Then a layer of polyimide was deposited thereon to a thickness of 
70 nm or so, and a rubbing process was executed to form an aligning film, 
thereby constituting a row-electrode substrate in such a manner that 
liquid crystal molecules have a twist angle of 240.degree. at the time of 
completion of a cell by combining the row-electrode substrate with the 
aforementioned column-electrode substrate. 
Such row-electrode substrate and column-electrode substrate were assembled 
as in the foregoing examples to produce a dot matrix LC cell. Subsequently 
an LC cell for retardation compensation was superposed thereon as in 
Example 1, and a pair of polarizing plates were disposed on the two sides 
to manufacture a negative type LCD device. 
In the LCD device thus obtained, the inter-substrate gap was rendered more 
uniform than that in Comparative Example 1. However, the surface 
irregularities became greater than those in Example 1 due to the structure 
where the color filters and the light shielding layers were disposed on 
the electrodes, so that the uniformity of the inter-substrate gap was 
slightly inferior to that in Example 1. 
Although a visually satisfactory color display was attained, the existence 
of the thick color filters on the electrodes caused variations in the 
effective voltage applied substantially to the liquid crystal layer, hence 
reducing the contrast as compared with Example 1 and slightly lowering the 
visual quality in the display. 
EXAMPLE 7 
Thin-film light shielding layers of chromium were formed to a thickness of 
100 nm on a glass substrate, and thick-film color filters wer formed by 
R-G-B three color dyeing process to a thickness of 2.0 .mu.m on electrode 
portions corresponding to pixels, in such a manner that the peripheries of 
the color filters were overlapped with the light shielding layers. And 
further an overcoat film (leveling layer) of transparent acrylic resin was 
formed thereon. 
As mentioned, the surface leveling was thus executed by forming such an 
overcoat film of transparent acrylic resin on the color filters and the 
light shielding layers, but it was difficult to attain complete flatness 
of the surface. However, fine irregularities on the color filters were 
mostly leveled due to the existence of such an overcoat film, and some 
large irregularities resulting from mutual overlaps of the color filters 
and the light shielding layers in the peripheries of the pixels were 
eliminated considerably in comparison with the conventional example using 
no such overcoat film. 
Thereafter such leveled surface was coated with ITO to a thickness of 240 
nm and then was patterned to form striped 272 row electrodes, and further 
a layer of polyimide was deposited thereon to a thickness of 70 nm or so. 
Subsequently a rubbing process was executed to form an aligning film, 
thereby constituting a row-electrode substrate. 
Meanwhile, striped 1056 column electrodes were formed on another glass 
substrate orthogonally to the row electrodes, and an insulator film of 
SiO.sub.2 -TiO.sub.2 was formed to a thickness of 50 nm on the entire 
surface. Then a layer of polyimide was deposited thereon to a thickness of 
70 nm or so, and a rubbing process was executed to form an aligning film, 
thereby constituting a column-electrode substrate in such a manner that 
liquid crystal molecules have a twist angle of 240.degree. at the time of 
completion of a cell by combining the column-electrode substrate with the 
aforementioned row-electrode substrate. 
The row-electrode substrate and the column-electrode substrate were so 
arranged that the twist angle of liquid crystal molecules was 240.degree., 
and a cell was constituted by sealing up the peripheries of the 
substrates. And a dot matrix LC cell was produced with a supply of nematic 
liquid crystal material therein. 
A layer of polyimide was deposited to a thickness of 70 nm on a glass 
substrate, and it was processed by rubbing to form an aligning film Two of 
such substrates were so arranged that liquid crystal molecules have a 
twist angle of 240.degree. in the reverse direction with respect to the 
dot matrix LC cell and, after sealing at the peripheries, nematic liquid 
crystal material was poured therein to produce an LC cell for retardation 
compensation. 
The dot matrix LC cell was superposed on such retardation compensating LC 
cell to constitute a laminated structure, and a pair of polarizing plates 
were disposed on the two sides thereof to manufacture a negative type LCD 
device. 
Out of the total 1056.times.272 dots in the LCD device thus obtained, 
merely 960.times.240 dots alone in the central area were used for display, 
and a non-selective voltage was applied to the electrodes in the 
peripheral region place them in a light-shielded state. 
In this LCD device where the display region and the peripheral region are 
furnished with the color filters and the light shielding layers having the 
same pattern (same area) respectively, so that the gap between the 
substrates is rendered substantially uniform in both the display region 
and the peripheral region, hence ensuring a visually satisfactory color 
display. 
EXAMPLE 8 
The entire surface between the periphery region and the seal in Example 7 
was covered with a light shielding layer, whereby the space between the 
seal and the display region could be widened even though the peripheral 
region was narrow, hence achieving further enhanced uniformity. 
EXAMPLE 9 
Light shielding layers formed by the dyeing process to a thickness of about 
1.2 .mu.m as in Example 4 were used in place of the light shielding layers 
and the color filters in Example 7, and both light shielding layers and 
color filters were formed to serve as the dyed color filters having a 
thickness of about 1.8 .mu.m. 
In this negative type LCD device also, the display region and the 
peripheral region were furnished with the color filters and the light 
shielding layers having the same pattern (same area) respectively, so that 
the gap between the substrates was rendered substantially uniform in both 
the display region and the peripheral region, whereby the uniformity of 
the background color was less conspicuous than in Example 4 and a visually 
satisfactory color display was attained. 
EXAMPLE 10 
In Example 9, the color filters and the light shielding layers were formed 
correspondingly to 1056.times.272 dots, and 960 column electrodes and 240 
row electrodes were formed in the display region. However, in the 
peripheral region, the respective 16 electrodes were grouped together into 
a single wide electrode. Consequently, in the peripheral region, there 
were disposed three striped column electrodes on each of the left and 
right sides and one striped row electrode at each of the upper and lower 
positions, thereby enabling visual representation with 960.times.240 dots 
in the display region. 
In this negative type LCD device also, the display region and the 
peripheral region were furnished with the color filters and the light 
shielding layers having the same pattern (same area) respectively, so that 
the inter-substrate gap in the display region was substantially uniform to 
eventually achieve a visually satisfactory color display. 
EXAMPLE 11 
Electrodes of ITO equal in pitch to striped 1056 column electrodes for 
color filters were electrodeposited on a glass substrate, and R-G-B three 
color filters having a thickness of 2.0 .mu.m were formed by 
electrodeposition. And light shielding layers equal in thickness thereto 
were formed by printing in the space between the color filters. 
An overcoat film of transparent acrylic resin was formed on the color 
filters, and further it was coated with ITO to a thickness of 240 nm and 
then patterned to form striped 272 row electrode groups. Subsequently a 
layer of polyimide was deposited to a thickness of 70 nm or so, and a 
rubbing process was executed to form an aligning film thereby constituting 
a row-electrode substrate. 
Meanwhile, striped 1056 column electrode groups were formed on another 
glass substrate orthogonally to the aforementioned row electrode groups, 
and an insulator film of SiO.sub.2 -TiO.sub.2 was formed on the entire 
surface to a thickness of 50 nm. Subsequently a layer of polyimide was 
deposited thereon to a thickness of 70 nm or so, and a rubbing process was 
executed to form an aligning film, thereby constituting a column-electrode 
substrate in such as a manner that liquid crystal molecules have a twist 
angle of 240.degree. at the time of completion of a cell of combining the 
column-electrode substrate with the aforesaid row-electrode substrate. 
The row-electrode substrate and the column-electrode substrate were 
combined with each other to manufacture an LCD device as in Example 7. 
The device thus assembled had a capability of display with 960.times.240 
dots. 
In this negative type LCD device also, both the display region and the 
peripheral region are furnished with the color filters, light shielding 
layers and electrodes having the same pattern (same area) respectively, so 
that the inter-substrate gap in the display region becomes substantially 
uniform to consequently attain a visually satisfactory color display. 
EXAMPLE 12 
The entire surface between the periphery region and the seal in Example 11 
was covered with a light shielding layer, whereby the space between the 
seal and the display region could be widened even though the peripheral 
region was narrow, hence achieving further enhanced uniformity. 
EXAMPLE 13 
A glass substrate was coated with ITO and then patterned to form striped 
240 row electrode groups and thick-film light shielding layers were formed 
to a thickness of 1.2 .mu.m by a dyeing process. Subsequently R-G-B three 
color filters having a thickness of 2.0 .mu.m were formed by a dyeing 
method. Then, a layer of polyimide was deposited thereon to a thickness of 
70 nm or so, and a rubbing process was executed to form an aligning layer, 
thereby constituting a column-electrode substrate. 
Meanwhile, striped 960 column electrode groups were formed on another glass 
substrate in a manner to be orthogonal to the row electrode groups, and an 
insulator film of SiO.sub.2 -TiO.sub.2 was formed to a thickness of 50 nm 
on the entire surface. Then a layer of polyimide was deposited thereon to 
a thickness of 70 nm or so, and a rubbing process was executed to form an 
aligning film, thereby constituting a row-electrode substrate in such a 
manner that liquid crytal molecules have a twist angle of 240.degree. at 
the time of completion of a cell by combining the column-electrode 
substrate with the aforementioned row-electrode substrate. 
Such row-electrode substrate and column-electrode substrate were assembled 
as in Example 7 to produce a dot matrix LC cell. Subsequently an LC cell 
for retardation compensation was superposed thereon as in Example 7, and a 
pair of polarizing plates were disposed on the two sides to manufacture a 
negative type LCD device having a display capacity of 912.times.208 dots. 
Although a visually satisfactory display was achieved in this LCD device, 
there occurred, due to the existence of the thick color filters on the 
electrodes, some variations in the effective voltage applied substantially 
to the liquid crystal layer, so that the contrast was lower than that in 
Example 7 and the display quality was slightly inferior. 
EXAMPLES 14-26 
Instead of the retardation compensating LC cell used in Examples 1 to 13, 
an optical compensating sheet composed of a uniaxial polymer film of 
polycarbonate was superposed on each of the two surfaces of the dot matrix 
LC cell to manufacture an LCD device. 
Such LCD device was connected to a driving circuit and then was-driven in 
the same manner as Examples 1 to 13. The resultant effects attained were 
similar to those in the foregoing examples. 
EXAMPLES 27-39 
Instead of the retardation compensating LC cell used in Examples 1-13, two 
optical compensating sheets composed of uniaxial polymer films of 
polycarbonate were superposed on one surface of the dot matrix LC cell to 
manufacture an LCD device. 
Such LCD device was connected to a driving circuit and then was driven in 
the same manner as in Examples 1-13. The resultant effects attained were 
similar to those in Examples 1-13. 
According to the present invention, as described hereinabove, the gap 
between the substrates can be maintained uniform with facility to 
eventually realize a visually satisfactory color display. 
In particular, great effects are attainable by applying the present 
invention to the STN type LCD device where high uniformity is requisite 
with respect to the inter-substrate gap although there are ensured some 
advantages including satisfactory multiplexing display characteristics, 
wide viewing angle, high contrast and so forth. Similarly, remarkable 
effects can be achieved by applying the present invention to a 
ferro-electric LCD device. 
With adoption of the constitution shown in FIGS. 1 and 2, color-filters for 
both the display region and the peripheral region can be produced by using 
the same mask or printing plate, hence realizing high productivity. 
Furthermore, due to the additional provision of electrodes in the 
peripheral region as well, any variation in the inter-substrate gap is 
suppressed in the vicinity of the boundary between the peripheral region 
and the display region, whereby such inter-substrate gap is retained 
substantially uniform even at the outermost periphery of the display 
region, hence averting nonuniformity of the background color. 
Particularly in the exemplary constitution of FIG. 2 where the frame-like 
light shielding layers and the color filters for the pixels therein are 
disposed in the peripheral region as well as in the display region, so 
that the gap control in the display region is made further uniform by 
applying a voltage to the peripheral pixels in a manner to keep them in a 
light-shielded state. Although the uniformity of the inter-substrate gap 
in the peripheral region is somewhat lower than that in the display 
region, since the peripheral region is so driven as to be kept in a 
light-shielded state, it is hardly recognized as the nonuniformity of the 
background color to eventually enhance the display quality. In addition, 
the display is rendered easier to be seen since the peripheral region is 
placed in a light-shielded state similarly to the light-shielded pixels in 
the display region. 
It is to be understood that the present invention is not limited to the 
above embodiments and examples and may be applicable also to a variety of 
modifications for use in known LCD devices within the scope not impairing 
the effects of the invention.