Liquid crystal device

By use of specific color filters in Surface Stability Ferroelectric Liquid Crystal Device having color filters assembled therein, generation of alignment defect ocurring in the initial alignment control step could be avoided.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a ferroelectric liquid crystal device such as a 
liquid crystal display device or a liquid crystal-optical shutter array, 
etc., more particularly to a ferroelectric liquid crystal device having a 
color filter improved in display and driving characteristics by obtaining 
a liquid crystal phase of uniform mono-domain without alignment defect 
through improvement of the initial alignment state of liquid crystal 
molecules. 
2. Related Background Art 
Liquid crystal devices known in the art may be, for example, those using 
twisted nematic crystal as disclosed in M. Schadt and W. Helfrich, 
"Applied Physics Letters", vol. 18, No. 4 (published on Feb. 15, 1971), p. 
127-128, "Voltage Dependent Optical Activity of a Twisted Nematic Liquid 
Crystal". The TN liquid crystal, which involves the problem of generating 
crosstalk during time divisional driving by use of a matrix electrode 
structure with increased picture element density, has been limited in 
number of picture elements. 
Also, a display device of the system in which switching elements with thin 
film transistors are connected with the respective picture elements and 
each picture element is subjected to switching has been known, but the 
step of forming thin film transistors on a substrate is extremely 
complicated and furthermore there is the problem that a display device 
with a large area can be prepared with difficulty. 
As the device solving these problems, Clerk et al. proposed a ferroelectric 
liquid crystal device in U.S. Pat. No. 4,367,924. 
This ferroelectric liquid crystal device is generally called Surface 
Stability Ferroelectric Liquid Crystal (SSFCC), and is set at a 
sufficiently thin film thickness (e.g., 1 to 2 .mu.m) in order to unwind 
the spiral structure inherently possessed by the chiral smectic liquid 
crystal. According to Unexamined Japanese Patent Publication No. 
147232/1986 of Tsuboyama, it has been clarified that when there is a 
stepped difference of 1000 .ANG. or more within the substrate plane used 
in the cell forming SSFLC, an alignment defect portion will be generated 
around a stepped portion. 
Whereas, for applying the aforementioned ferroelectric liquid crystal 
device to color display, it may be conceivable to arrange a color filter 
within the cell. 
In general, a color filter is a structure of a group of color filter units 
(each being one R, G or B filter) of red color (R), green color (G) and 
blue color (B) arranged in a stripe or mosaic shape. Since each color 
filter unit is formed of a resin film colored into R, G or B, there 
occurred a stepped difference of about 2000 .ANG. to 1 .mu.m within the 
substrate plane when such color filters were arranged within the cell. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a liquid crystal device 
improved in generation of the alignment defect which is attributable to 
the stepped difference within the substrate plane caused by arrangement of 
color filters within the cell. 
More specifically, the present invention has the specific features in a 
liquid crystal device which has minimized the influence onto alignment 
stability of the ferroelectric liquid crystal by the stepped difference 
caused by arrangement of color filters within the cell, namely: 
firstly in a liquid crystal device comprising: 
(a) a pair of transparent electrodes having a plurality of confronting 
portions formed therebetween; 
(b) a pair of substrates supporting each of said pair of transparent 
electrodes; 
(c) a group of color filters comprising a plurality of color filters 
arranged on the innerside of at least one of the above pair of substrates 
and arranged at positions corresponding to each of said plurality of 
confronting portions, provided that the relationship of 
0.ltoreq..alpha..ltoreq.5 is satisfied where .alpha.(.mu.m) is the 
interval of the color filter between the adjacent confronting portions; 
and 
(d) a ferroelectric liquid crystal arranged between said pair of 
substrates; 
secondly in a liquid crystal device comprising: 
(a) a pair of transparent electrodes having a plurality of confronting 
portions formed therebetween; 
(b) a pair of substrates supporting each of said pair of transparent 
electrodes; 
(c) a group of color filters comprising a plurality of color filters 
arranged on the innerside of at least one of the above pair of substrates 
and arranged at positions corresponding to each of said plurality of 
confronting portions, provided that the color filters positioned at at 
least two confronting portions of the plural confronting portions are 
different in film thickness and the relationship of 
X.ltoreq.(1/10).multidot.d.sub.0 is satisfied where d.sub.0 is the 
interval (.mu.m) between the above pair of substrates and X(.mu.m)is the 
maximum film thickness difference; and 
(d) a ferroelectric liquid crystal arranged between said pair of 
substrates; 
thirdly in a liquid crystal device comprising: 
(a) a pair of transparent electrodes having a confronting portion formed 
therebetween; 
(b) a pair of substrates supporting each of said pair of transparent 
electrodes; 
(c) color filters arranged on the innerside of at least one of the above 
pair of substrates and arranged at positions corresponding to said 
confronting portion; 
(d) resin films arranged adjacent to said color filters, the resin films 
having a first resin film and a second resin film formed with a resin 
solution having a viscosity higher than the resin solution used when said 
first resin film is formed; and 
(e) a ferroelectric liquid crystal arranged between said pair of 
substrates; 
fourthly in a liquid crystal device comprising: 
(a) a pair of transparent electrodes forming a plurality of confronting 
portions; 
(b) a pair of substrates supporting each of said pair of transparent 
electrodes; 
(c) a group of color filters comprising a plurality of color filters 
arranged on the innerside of at least one of the above pair of substrates 
and arranged at positions corresponding to each of said plurality of 
confronting portions, said color filters being formed in trapezoidal 
shapes, provided that the relationships of 0.degree.&lt;.theta.&lt;90.degree. 
and 0&lt;W.ltoreq.d/tan .theta. are satisfied where d(.mu.m) is the thickness 
of said color filter, .theta.(degree) is the sectional taper angle between 
the lower bottom of the color filter and the diagonal side thereof and 
W(.mu.m) is the overlapping width between the adjacent color filters; and 
(d) a ferroelectric liquid crystal arranged between said pair of 
substrates; 
fifthly in a liquid crystal device comprising: 
(a) a pair of transparent electrodes forming a plurality of confronting 
portions; 
(b) a pair of substrates supporting each of said pair of transparent 
electrodes; 
(c) a group of color filters comprising a plurality of color filters 
arranged on the innerside of at least one of the above pair of substrates 
and arranged at positions corresponding to each of said plurality of 
confronting portions; 
(d) a heat-fusible resin film arranged at the gap between the adjacent 
color filters; and 
(e) a ferroelectric liquid crystal arranged between said pair of 
substrates; and 
sixthly in a liquid crystal device comprising: 
(a) a pair of transparent electrodes forming a plurality of confronting 
portions; 
(b) a pair of substrates supporting each of said pair of transparent 
electrodes; 
(c) a group of color filters comprising a plurality of color filters 
arranged on the innerside of at least one of the above pair of substrates 
and arranged at positions corresponding to each of said plurality of 
confronting portions, provided that the relationship of 
0.ltoreq.l/d.ltoreq.5 is satisfied where l(.mu.m) is the interval between 
the color filters of the adjacent confronting portions and d(.mu.m) is the 
film thickness of said color filter; and 
(d) a ferroelectric liquid crystal arranged between said pair of substrates 
.

DETAILED DESCRIPTION OF EMBODIMENTS 
The present inventors have found, as a result of experiments, that no 
alignment defect is generated by setting the interval .alpha.(.mu.m) 
between the filter units of the color filter built in the cell at 5 .mu.m 
or less, regardless of the above stepped difference. Particularly, it has 
been found that by setting the interval .alpha.(.mu.m) between the filter 
units at 5 .mu.m or less upon formation of the initial alignment state in 
the temperature drop process when the ferroelectric liquid crystal is 
transferred from the isotropic phase (high temperature state) to the 
liquid crystal phase (low temperature state), no alignment defect is 
generated. 
Referring to the drawings, the present invention is explained below. 
FIG. 1 is a sectional view showing the basic constitution of the 
ferroelectric liquid crystal device according to the present invention. In 
FIG. 1, the ferroelectric liquid crystal device 11 has substrates 12 and 
13 using transparent plates such as glass plate or plastic plate, and has 
a ferroelectric liquid crystal 14 sandwitched therebetween. The respective 
substrates 12 and 13 have the respective transparent electrodes 15 and 16 
in patterns of stripes for forming matrix electrode structures arranged 
thereon, and on the transparent electrodes are formed alignment control 
films 17 and 18. The respective color units of red (R), green (G) and blue 
(B) are formed of materials with colored material concentrations 
previously set so as to give desired spectral characteristics when their 
film thickness are equal to each other. On the other hand, for effecting 
further flattening, a light intercepting layer 10 is formed in the recess 
between the respective color units, if necessary, and further a protective 
film or a flattening layer 19 is formed thereon. 
In the substrates according to the above constitution, by setting the film 
thickness of the color filters at substantially the same and suppressing 
the interval between the filter units at 5 .mu.m or less, the stepped 
difference due to the recess is corrected, and therefore the substrate 
surface can be maintained substantially flat, even if transparent 
electrodes and alignment control films may be successively formed on the 
filter units. 
In the present invention, by flattening as described above, the stepped 
difference of the color filter substrate can be set at 1000 .ANG. or less, 
preferably 500 .ANG. or less. If the stepped difference exceeds 1000 
.ANG., in other words, if a non-flattened layer with the intervals between 
the respective filter units set in the range exceeding 5 .mu.m is used, 
the liquid crystal device will give rise to an alignment defect in shape 
of a blade line as shown above in FIG. 5. 
The ferroelectric liquid crystal device of the present invention has the 
color filters of the respective filter units formed with substantially the 
same film thickness and also the interval .alpha.(.mu.m) between the color 
filters of the adjacent respective filter units is 
0.ltoreq..alpha..ltoreq.5 .mu.m, and therefore the flatness of the 
substrate becomes good. As the result, there is no stepped difference at 
the plane in contact with the liquid crystal phase, and the liquid crystal 
phase sandwitched between said substrates with good flatness is gradually 
cooled in the temperature process transferring from the isotropic phase to 
the liquid phase, whereby the liquid phase region is gradually expanded to 
form a liquid crystal phase of uniform monodomain. 
For example, to explain by referring to the above mentioned DOBAMBC 
exhibiting ferroelectric liquid phase as the liquid phase, when the 
isotropic phase of DOBAMBC is gradually cooled, phase transition to the 
smectic A phase (SmA phase) occurs at about 115.degree. C. At this time, 
if the substrate is subjected to orientation treatment such as rubbing or 
SiO.sub.2 oblique vapor deposition, a monodomain, in which the molecular 
axes of the liquid crystal molecules are parallel to the substrate and are 
aligned in one direction, is formed. As cooling is further progressed, 
phase transition to the chiral smectic C phase (SmC* phase) occurs at a 
specific temperature between about 90.degree. and 75.degree. C., depending 
on the thickness of the liquid crystal layer. Also, when the thickness of 
the liquid crystal layer is set at about 2 .mu.m or lower, the spiral of 
the SmC* phase is loosened to exhibit bistability. 
According to a preferred example of the present invention, it is desirable 
that the film thicknesses of the color filter units may differ for each of 
R, G and B, particularly with the maximum thickness being set for B color 
filter units, the minimum thickness for R color filter units, and the 
intermediate thickness for G color filter units. At this time the maximum 
film thickness difference X (.mu.m) corresponds to the film thickness 
difference between the B color filter units and the R color filter units, 
and generation of alignment defect can be avoided by having color filters 
built in within the cell, the filters being set at the relationship of 
X.ltoreq.(1/10).multidot.d.sub.0 where X(.mu.m) is the maximum film 
thickness difference and d.sub.0 (.mu.m) is the distance between a pair of 
the substrates. 
FIG. 2 shows a sectional view of the ferroelectric liquid crystal cell as 
described above, the same symbols as in FIG. 1 representing the same 
members. In the ferroelectric liquid crystal device shown in FIG. 2, the 
relationship of X.ltoreq.(1/10).multidot.d.sub.0 preferably 
(1/20).multidot.d.sub.0 is satisfied where X(.mu.m) is the maximum film 
thickness difference of the color filter units (R, G, B) and d.sub.0 
(.mu.m) is the interval of a pair of substrates 12 and 13. Also, as is 
clarified in Examples as described below, if X is set to exceed 
(1/10).multidot.d.sub.0 alignment defect will occur from the stepped 
portion, and the ferroelectric liquid crystal at such alignment defect 
portion was found to give rise to switching defect (exhibiting no normal 
driving characteristics). 
The film thicknesses dR, dG, dB of the color filter units, R, G and B used 
in the ferroelectric liquid cell shown in FIG. 2 may be set each within 
the range of 0.5 .mu.m to 1.5 .mu.m, particularly preferably at dB&gt;dG&gt;dR. 
In another preferable example of the present invention, generation of the 
above mentioned alignment defect can be prevented by improving the 
protective film arranged between the color filters and the transparent 
electrodes. 
FIG. 3 is a sectional view of such ferroelectric liquid crystal cell, in 
which the same symbols as in FIG. 1 represent the same members. 
In FIG. 3, the ferroelectric liquid crystal device 11 has substrates 12 and 
13 using transparent plates such as glass plate or plastic plate, and has 
a ferroelectric liquid crystal 14-sandwiched therebetween. The respective 
substrates 12 and 13 have the respective transparent electrodes 15 and 16 
in patterns of stripes for forming matrix electrode structures arranged 
thereon, and on the transparent electrodes are formed alignment control 
films 17 and 18. The respective color units of red (R), green (G) and blue 
(B) are formed with film thicknesses set depending on the desired spectral 
characteristics with stepped differences to some extent. 
On the other hand, if desired, a light intercepting layer 10 is formed in 
the gap between the respective color units. Also, on the color filters, a 
first transparent resin film 31, which is formed of a lower viscosity 
resin and is a flattened layer flattening the stepped difference between 
the picture elements, and a second transparent resin film 32, which is 
formed of a higher viscosity resin and is the flattened layer and the 
protective layer for the color filters, are successively laminated. 
In the substrate according to the above constitution, since the stepped 
difference due to film thicknesses of color filters and the recess between 
the filter units is corrected, the substrate plane can be maintained 
substantially flat. 
The color filter to be used in the present invention is not particularly 
limited, provided that it has characteristics such as environmental 
resistance for the conditions in the steps for formation of the 
ferroelectric liquid crystal device and also has desired durability. It 
may be prepared by forming a pigment and a layer containing it into a 
pattern. The layer thickness may be determined depending on the desired 
spectral characteristics. It may be generally about 0.5 to about 5 .mu.m, 
preferably about 0.5 to about 1.5 .mu.m, with the layer thickness of each 
color being preferably as small as possible. 
Further, in some cases, in order to improve the display characteristics and 
make the stepped difference in the gap between the respective color filter 
units, a light intercepting layer can be more effectively formed by 
depositing a metallic thin film having light intercepting ability such as 
chromium, aluminum, etc. according to the vapor deposition method or by 
applying a light intercepting resin film containing a material having 
light intercepting ability such as carbon black, composite oxide black 
pigment, metal powder, etc. dispersed in a photosensitive polyamino type 
resin according to the coating method. 
The first transparent resin film 31 of the present invention is formed 
primarily for the purpose of flattening the stepped difference on the 
substrate formed after color filter formation. Accordingly, a resin made 
to have a lower viscosity is used, and generally a viscosity of 50 cps 
(centipoise) or less/(under room temperature), preferably a viscosity of 
20 to 50 cps is desirable. The color filter surface is coated with 
liquids, which are controlled to lower viscosity, of organic resin such as 
polyamide type, polyimide type, polyurethane type, acrylic type, 
polycarbonate type and silicone type, etc. or solutions of the 
photosensitive resins thereof according to the coating method such as spin 
coating, roll coating, dipping, etc., and then are subjected to the 
photolithographic processing, forming the resin film. Its film thickness 
may be the thickness necessary for filling the unit gap portion of the 
color filter, and it is preferable that the thickness is set to be equal 
to or slightly thicker than the thickness of the thickest unit. 
The second transparent resin film 32 is formed on the layer which has been 
substantially flattened with the first transparent resin film 31, and is 
formed for the purpose of flattening further the stepped difference owing 
to the color filters and primarily protecting the color filters. 
Accordingly, with a resin material with increased resin component, with a 
viscosity generally exceeding 50 cps (centipoise)/(under room 
temperature), preferably controlled within the range of about 100 cps to 
about 1200 cps, for example, with organic resin liquids such as polyamide 
type, polyimide type, polyurethane type, acrylic type, polycarbonate type 
and silicone type, etc. or solutions of the photosensitive resins, the 
film 31 are coated according to the coating method such as spin coating, 
roll coting, dipping, etc., and then are subjected to the 
photolithographic steps, forming the resin film 32. 
As to the resin material for forming the second resin film 32, it may be 
same as a material of the first transparent resin film 31 or different, 
and any desired material can be selected from those having resistance to 
the respective environments in the cell forming steps of the ferroelectric 
liquid crystal device and having desired reliability, etc. Its layer 
thickness may be set as desired from the viewpoints as mentioned above. 
The layer is generally formed with a thickness of about 0.5 to about 5 
.mu.m, preferably about 0.5 to about 1.0 .mu.m. 
According to another preferable example of the present invention, the color 
filter unit is formed in a trapezoidal shape, and generation of alignment 
defect as described above can be avoided by having a group of color 
filters built in the cell, said group having the relationships of 
0.degree.&lt;.theta.&lt;90.degree. and 0&lt;w .ltoreq.d/tan .theta. where d(.mu.m) 
is the film thickness of said color filter unit, .theta.(degree) is the 
sectional tapered angle between the bottom and the diagonal side of the 
color filter unit and w(.mu.m) is the overlapping width between the 
adjacent color filter units. 
FIG. 4A is a sectional view of the ferroelectric liquid crystal cell as 
described above, with the same symbols as in FIG. 1 representing the same 
members. 
In the cell shown in FIG. 4, the respective color filter units of R (red), 
G (green) and B (blue) are formed in trapezoidal shapes, with the colorant 
concentrations being previously set to give desired spectral 
characteristics in equal film thicknesses, the tapered angles being formed 
by control of exposure, having overlapped portions at the adjacent units 
and a part of the diagonal sides thereof. 
More specifically, when d(.mu.m) is the film 
thickness of the color filter unit formed in trapezoidal shape as shown in 
FIG. 4B, .theta.(degree) is the sectional tapered angle between the bottom 
and the diagonal side of the color filter unit and w(.mu.m) is the 
overlapping width between the diagonal sides of the adjacent color filter 
units, 
(1) the range of the sectional tapered angle of one unit is set at 
0&lt;.theta.&lt;90.degree., and 
(2) the range of the overlapping width between the adjacent units is set at 
0&lt;w .ltoreq.d/tan .theta.. If necessary, a protective film or flattening 
film 19 is formed on the color filter layer. 
In the substrate 12 with the above constitution, since the stepped 
difference due to the film thicknesses of color filters and the recess 
between units is corrected, the substrate plane can be maintained 
substantially flat even when transparent electrode 15 and alignment 
control film 17 may be successively formed on the color filters. 
According to another example of the present invention, by arranging a 
heat-fusible resin film at the gap between the adjacent color filter units 
of the group of color filter units, generation of the above mentioned 
alignment defect can be avoided. 
FIG. 5 is a sectional view of the ferroelectric liquid crystal cell is 
mentioned above, with the same symbols as in FIG. 1 representing the same 
members. In FIG. 5, a heat-fusible resin film 51 is provided in a form 
such that the film binds the respective color filter units of R, G and B. 
The heat-fusible resin film 51 can be provided by coating at least one 
substrate with a heat-fusible resin and forming color filters on said 
heat-fusible resin film 51, or by coating the substrate having color 
filters formed thereon with a heat-fusible resin and then filling the 
color filter unit gap with the heat-fusible resin film 51 by means of 
heating or heating under pressurization. 
As the heat-fusible resin for forming the heat-fusible resin film 51 used 
in the present invention, there may be employed polyvinyl acetate, 
ethylene-vinyl acetate copolymer, polyvinyl chloride, vinyl chloride-vinyl 
acetate copolymer, polyamide, phenoxy resin, ethyl celulose, 
polyisobutylene, polyester, terpene resin, rosin and derivatives thereof, 
petroleum resin, etc., either singly or as a mixture. Desirably, it is 
effective to use a resin with high transparency. 
As the method for forming the heat-fusible resin film 51, the first method 
forms first a resin layer with a film thickness of about 0.5 to about 5 
.mu.m on a substrate according to the coating method such as spin coating, 
roll coating, dipping, etc. by use of a heat-fusible resin solution. Next, 
after formation of the color filter layer with pattern formation having 
the above constitution on said resin layer, the color filter pattern is 
embedded in the molten resin by the heating treatment under the melting 
temperature of the heat-fusible resin, or the hot press treatment in 
parallel to said color filter substrate surface, or by use of air blow, 
etc., simultaneously with flattening of the surface layer, and then are 
subjected to fixation by cooling to normal temperature. 
On the other hand, the second method comprises forming a color filter 
pattern on the substrate, then forming the heat-fusible resin film 51 
having the same film thickness according to the same coating method as in 
the above method, subsequently embedding the molten resin in the gaps of 
the color filter pattern by heat treatment, hot press treatment or air 
blow, etc. similarly as the above method, simultaneously by flattening the 
surface layer and then fixing the resulting resin by cooling to normal 
temperature. 
In some cases, for improving the display characteristics, a light 
intercepting layer can formed at the gaps of the respective color filter 
units by depositing a metal film having light intercepting ability such as 
chromium, aluminum, etc. according to the vapor deposition method or by 
applying a light intercepting resin layer containing a material having 
light intercepting ability such as carbon black, black pigment of 
composite oxides, metal powder, etc. according to the coating method. 
Further, when it is required to further increase adhesiveness between the 
heat-fusible resin or the color filter layer and the base substrate, it is 
more effective to precoat the substrate thin with a silane coupling agent 
before formation of the heat-fusible resin or the color filter layer, or 
to use the heat-fusible resin or the color filter layer into which a small 
amount of a silane coupling agent, etc. is previously added. 
For the purpose of protecting the color filter layer and the heat-fusible 
film 51 from various environmental conditions and further flattening the 
surface, an organic resin such as polyamide, polyimide, polyurethane, 
polycarbonate, silicone, etc. or an inorganic film such as Si.sub.3 
N.sub.4, SiO.sub.2, SiO, Al.sub.2 O.sub.3, Ta.sub.2 O.sub.3, etc. can be 
provided as the protective film or the flattening film generally having 
the thickness range of about 0.5 to about 5 .mu.m by the coating method 
such as spin coating, forming the resin film 32 by the vapor deposition 
method. 
According to another preferable example of the present invention, 
generation of the above mentioned alignment defect can be avoided by use 
of a group of color filter units satisfying the relationship of 
0.ltoreq.l/d.ltoreq.5 where l(.mu.m) is the interval between the adjacent 
color filter units in the group of color filter units and d(.mu.m) is the 
film thickness of the color filter unit. 
FIG. 6 shows a sectional view of the ferroelectric liquid crystal cell as 
mentioned above, with the same symbols as in FIG. 1 representing the same 
members. On the substrate 12 shown in FIG. 6 are formed the color filter 
units B, G and R with the same film thickness, and simultaneously the 
interval l(.mu.m) between the color filter units is set at 5-fold or less 
relative to the film thickness d(.mu.m) of the color filter unit. 
The color filter suitable for the present invention may be a filter 
according to the system capable of setting the film thicknesses of the 
respective color filter units at substantially same thickness. 
Particularly the system as described below, according to which a fine 
pattern can be formed by a simple production process and a color filter 
excellent in mechanical characteristics as well as various characteristics 
such as heat resistance, light resistance, solvent resistance, etc. can be 
afforded, is preferred. 
The optimum color filter for the present invention is formed by repeating 
the photolithographic step of a colored resin comprising a colorant 
material dispersed in an aromatic polyamide resin or polyimide resin 
having photosensitive groups in the molecule. 
More particularly, the aromatic polyamide resin or polyimide resin having 
photosensitive groups in the molecule for forming the colored resin layer 
possessed by the color filter may be preferably one which can give a cured 
film at 200.degree. C. or lower, for example, which is capable of forming 
a cured film by heating of about 150.degree. C. for 30 minutes, 
particularly one having no specific light absorption characteristic in the 
visible wavelength region (400-700 nm) (one having light transmittance of 
about 90% or more). From this standpoint, an aromatic polyamide resin is 
preferred. 
Also, as the group having photosensitivity in the present invention, 
aromatic chains having a photosensitive unsaturated hydrocarbon group as 
shown below may be employed. 
(1) Benzoic acid esters 
##STR1## 
(wherein R.sup.1 represents CHX=CY--COO--Z--, X represents --H or 
--C.sub.6 H.sub.5, Y represents --H or --CH.sub.3, Z represents--or an 
ethyl group or a glycidyl group); 
(2) Benzyl acrylates 
##STR2## 
(wherein Y represents --H or CH.sub.3); 
(3) Diphenyl ethers 
##STR3## 
(wherein R.sup.2 represents a group containing at least one of 
CHX.dbd.CY--CONH--, CH.sub.2 .dbd.CY--COO--(CH.sub.2).sub.2 --OCO-- or 
CH.sub.2 .dbd.CY--COO--CH.sub.2 --, X and Y represent the same groups as 
above); 
(4) Chalcons and other compound chains 
##STR4## 
(wherein R.sub.3 represents H--, an alkyl group or an alkoxy group); 
##STR5## 
and so on. 
Specific examples of the aromatic polyamide resin and polyimide resins 
having these groups in the molecules may include "Risocoat PA-1000" (trade 
name, produced by Ube Kosan K.K.), "Risocoat PI-400" (trade name produced 
by Ube Kosan K.K.). 
Generally, few photosensitive resins used in the photolithographic step are 
excellent in mechanical characteristics and durability such as heat 
resistance, light resistance, solvent resistance, although there in such 
characteristics may be different depending on the chemical structure. In 
contrast, the above photosensitive polyamino type resin of the present 
invention is a resin excellent in these durabilities, also in chemical 
structure, and the durability of the color filter formed by use of these 
also becomes very good. Particularly, excellent performances will be 
exhibited for heat resistance during sputter formation of a transparent 
electroconductive film on the color filter and for breakage of the color 
filter owing to inner spacer during assembling of the liquid crystal 
device, such heat resistance and breakage being significant for the color 
filter for ferroelectric liquid crystal device. 
The colorant material for forming the colored resin layer possessed by the 
color filter in the present invention is not particularly limited in 
organic pigments, inorganic pigments, dyes, etc., provided that desirable 
spectral characteristics can be obtained. In this case, each material can 
be used singly or as a mixture of some of these. However, when a dye is 
used, the performance of the color filter is governed by the durability of 
the dye itself, but by use of the above resin system, a color filter with 
more excellent performance than conventional dyed color filter can be 
formed. Accordingly, in view of the color characteristics and various 
performances of the color filter, an organic pigment is the most preferred 
as the colorant material. 
As the organic pigment, there may be employed typically azo type pigments 
such as soluble azo type, insoluble azo type, condensed azo type, etc., 
also phthalocyanine type pigments, and indigo type, anthraquinone type, 
perylene type, perynone type, dioxazine type, quinacridone type, 
isoindolinone type, phthalone type, methine azomethine type, other 
condensed polycyclic pigments containing metal complex type or mixtures of 
some of these. 
In the present invention, the colored resin to be used for formation of the 
colored resin layer may be prepared by formulating each of the above 
colorant materials having desired spectral characteristics under the same 
film thickness for each color into the above photosensitive polyamino type 
resin solution at a proportion of about 10 to about 70 wt. %, dispersing 
sufficiently the colorant materials by use of supersonic, three-rolls, 
ball mill, sand mill, etc., and preferably then removing the colorant 
material of great particle size through a filter of 1 .mu.m or less. 
The colored resin layer possessed by the color filter in the present 
invention is formed by coating the above colored resin onto a substrate 
according to a coating device such as spinner, roll coater, etc. and then 
forming it into a pattern shape according to the photolithographic step, 
and its layer thickness may be determined depending on the desired 
spectral characteristics. The colored layer generally has the same 
thickness for each color of about 0.5 to about 3.0 .mu.m, preferably about 
0.5 to about 1.5 .mu.m. 
When it is required to further increase adhesion between the colored resin 
layer and the substrate of the base, it is further effective to coat 
previously the substrate thin with a silane coupling agent, etc. before 
pattern formation of the colored resin, or to form the color filter by use 
of a material having a small amount of a silane coupling agent, etc. 
previously added into the colored resin. 
The colored resin layer possessed by the color filter of the present 
invention is constituted of a material having itself sufficient 
durability. Particularly, for protection of the colored resin layer from 
various environmental conditions or flattening of the color filter 
surface, an organic resin such as polyamide, polyimide, polyurethane, 
polycarbonate, silicone type, etc. or an inorganic film such as Si.sub.3 
N.sub.4, SiO.sub.2, SiO, Al.sub.2 O.sub.3, Ta.sub.2 O.sub.3, etc. can be 
provided as the protective film or the flattening film according to the 
coating method such as spin coating, roll coating, etc., or according to 
the vapor deposition method. 
In this case, the color filter surface becomes a shape with less stepped 
difference, which is suitable for removing the alignment defect of the 
ferroelectric liquid crystal device as intended by the present invention. 
The film thickness of the protective film 19 can determine the film 
thickness of the ferroelectric liquid crystal 14 and therefore may vary 
depending on the kind of the liquid crystal material and the response 
speed required, etc., and it is generally set in the range of 0.2 .mu.m to 
20 .mu.m, preferably 0.5 .mu.m to 10 .mu.m. 
Also, in some cases, for improving display characteristics and making the 
gap stepped difference between the respective units smaller, light 
intercepting layers can be formed, correspondingly between the respective 
units, by depositing a metal thin film having light intercepting ability 
such as chromium, aluminum, etc. according to the deposition method or by 
applying a light intercepting resin layer containing a material having 
light intercepting ability such as carbon black, black pigment of 
composite oxides, metal powder, etc. dispersed in a photosensitive 
polyamide or polyimide resin according to the coating method. 
The material for the alignment control film to be used in the present 
invention may be selected from, for example, resins such as polyvinyl 
alcohol, polyimide, polyamideimide, polyester, polycarbonate, polyvinyl 
acetal, polyvinyl chloride, polyvinyl acetate, polyamide, polystyrene, 
cellulose resin, melamine resin, urea resin, acrylic resin, etc., or 
photosensitive polyimide, photosensitive polyamide, cyclic rubber type 
photoresist, phenol novolac type photoresist or electron beam photoresist 
(polymethyl methacrylate, epoxidized 1,4-polybutadiene, etc.) and so on. 
The thickness of the alignment control film 7 is set generally in the 
range of 10 .ANG. to 1 .mu.m, preferably 100 .ANG. to 3000 .ANG., 
depending on the film thickness of the ferroelectric liquid crystal. 
As the liquid crystal material to be used in the present invention, 
particularly suitable ones are liquid crystals having bistability and 
ferroelectric characteristics. Specifically, liquid crystals of the chiral 
smectic phase (SmC*), the H phase (SmH*), the I phase (SmI*), the J phase 
(SmJ*), the K phase (SmK*), the G phase (SmG*) or the F phase (SmF*) can 
be used. 
Details of the ferroelectric liquid crystals are described in "LE JOURNAL 
DE PHYSIQUE LETERS", 1975, 36, (L-69), "Ferroelectric Liquid Crystals"; 
"Applied Physics Letters", 1980, 36 (11), Submicro Second Bistable 
Electrooptic Switching in Liquid Crystals; "Solid Physics", 1981, 16 
(141), "Liquid Crystal", U.S. Pat. Nos. 4,561,726, 4,589,996, 4,596,667, 
4,613,209, 4,614,609, 4,639,089, and the ferroelectric liquid crystals 
disclosed in these references can be used in the present invention. 
Specific examples of ferroelectric liquid crystal may include 
desiloxybenzylidene-p'-amino-2-methylbutylcinnamate (DOBAMBC), 
hexyloxybenzylidene-p'-amino-2-chloropropylcinnamate (HOBACPC), 
4-o-(2-methyl)-butylresorcilidene-4'-octylaniline (MBRAS). 
When the device is constituted by use of these materials, since the 
temperature state is maintained so that the liquid crystal compound may 
become the chiral smectic phase, the device can be supported by, e.g., a 
block in which heater is embedded, if necessary. 
FIG. 7 illustrates schematically an example of cell for description of 
actuation of the ferroelectric liquid crystal. 71a and 71b are substrates 
(glass plates) covered with transparent electrode comprising a thin film 
of In.sub.2 O.sub.3, SnO.sub.2 or ITO (Indium Tin Oxide), etc., and 
therebetween is sealed a liquid crystal of the SmC* phase or the SmH* 
phase with a plurality of liquid crystal molecular layers 72 being aligned 
perpendicularly to the glass surface. The line 73 indicated by bold line 
represents the liquid crystal molecule, and the liquid crystal molecule 73 
has dipole moment (P.perp.) 74 in the direction orthogonal to the 
molecule. When a voltage of a certain threshold value or higher is applied 
between the electrodes on the substrate 71a and 71b, the spiral structure 
of the liquid crystal molecule 73 can be loosened to change the aligned 
direction of the liquid crystal molecules 73 so that the dipole moment 
(P.perp.) 74 may be all directed to the electrical field direction. The 
liquid crystal molecule 73 has a slender shape, exhibiting refractive 
index anisotropy in its longer axis direction and shorter axis direction. 
Therefore, it is readily understood that when, or example, polarizers 
positioned at the positional relationship of crossed Nicols to each other 
are arranged on upper and lower sides of the glass surface, a liquid 
crystal optical modulating device can vary its optical characteristics 
according to the polarity of the applied voltage. 
The liquid crystal cell to be used preferably in the ferroelectric liquid 
crystal device of the present invention can have a thickness which can be 
made sufficiently thin (e.g. 10 .mu. or less). As the liquid crystal phase 
becomes thus thinner, the spiral structure of the liquid crystal molecule 
will be loosened even when no electrical field is applied, becoming a 
non-spiral structure, whereby its dipole moment Pa or Pb takes either the 
state directed upwardly (84a) or downwardly (84b). When an electrical 
field Ea or Eb with different polarity of a certain threshold value or 
higher is imparted to such a cell, the dipole moment will change the 
direction upwardly 84a or downwardly 84b corresponding to the electrical 
field vector of the electrical field Ea or Eb, whereby the liquid crystal 
molecules will be aligned in either one of the first stable state 83a or 
the second stable state 83b. 
There are two advantages as mentioned above brought about by use of such 
ferroelectric liquid crystal as the optical modulating device. The first 
one is the extremely rapid response speed, and the second one is that the 
alignment of liquid crystal molecules has bistability. To explain further 
the second point by referring to, for example, FIG. 8, liquid crystal 
molecules will be aligned into the first stable state 83a by application 
of the electrical field Ea, and this state is stable even if the 
electrical field may be turned off. On the other hand, when the electrical 
field Eb in the opposite direction is applied, the liquid crystal 
molecules will be aligned into the second stable state 83b to change the 
direction of molecules, but they also remain under this state even when 
the electrical field may be turned off. Also, as long as the electrical 
field Ea does not exceed a certain threshold value, the respective aligned 
states are still maintained. For such rapid response speed and bistability 
to be realized effectively, the cell should be preferably as thin as 
possible. 
For the ferroelectric liquid crystal device exhibit desired driving 
characteristics, the ferroelectric crystal arranged between a pair of 
parallel substrates is required to take the molecular alignment state such 
that conversion between the above two stable states may effectively occur 
irrespectively of the applied state of electrical field. For example, for 
a ferroelectric liquid crystal having the chiral smectic phase, it is 
required that a region in which the liquid crystal molecule layer of the 
chiral smectic phase is arranged vertically to the substrate surface, and 
therefore the liquid crystal molecule axis in substantially parallel to 
the substrate surface (monodomain) should be formed. For this purpose, a 
uniformly aligned monodomain can be effectively formed with the alignment 
control films 17 and 18 as described above. 
The present invention is described in detail below by referring to the 
following Examples. 
EXAMPLE 1 
FIGS. 9A-9F are diagrams of the steps showing the formation steps of the 
color filter units of the three colors R, G and B. 
First, on #7059 glass substrate 91 produced by Corning was formed a colored 
resin layer 92 by coating of a blue colored resin material capable of 
obtaining desired spectral characteristics [the blue colored resin 
material being a photosensitive colored resin material prepared by 
dispersing Heliogen Blue L7080 (trade name, produced by BASF Co., C.I. No. 
74160) in PA-11000C (trade name, produced by Ube Kosan K.K., polymer 
content=10%, solvent: N-methyl pyrrolidone, pigment:polymer=1:2)]according 
to spinner coating to a film thickness of 1.5 .mu.m (see FIG. 9A). 
Next, said colored resin layer 92, after prebaked at 80.degree. C. for 30 
minutes, was subjected to exposure by use of a high pressure mercury lamp 
through a photomask 93 corresponding to the pattern shape to be formed 
(see FIG. 9B). 
After exposure, as shown in FIG. 9C, the layer 92 was developed by use of 
supersonic with an 
exclusive developer (comprising N-methyl-2-pyrroidone as the main 
component) which dissolved only the unexposed portion of the colored resin 
layer 92 having the photocured portion 92a, and then the layer 92 was 
treated with an exclusive rinse solution (e.g. a rinse solution comprising 
isopropyl alcohol as the main component), followed by post-baking at 
150.degree. C. for 30 minutes, to form a blue pattern colored resin layer 
94 having a pattern shape (see FIG. 9D). 
Subsequently, on the glass substrate having a blue colored pattern formed 
thereon, a green pattern colored resin layer 95 was formed at the 
predetermined portion on the substrate with an interval of 5 .mu.m or less 
set from the blue colored resin layer in the same manner as described 
above except for using as the second color a green colored resin material 
[photosensitive colored resin material prepared by dispersing Lionol Green 
6YK (trade name, produced by Toyo Ink, C.I. No. 74265) in PA-1000 C (trade 
name, produced by Ube Kosan K.K., polymer content=10%, solvent: 
N-methyl-2-pyrrolidone, pigment:polymer=1:2)]. 
Further, on the substrate having thus formed blue and green patterns 
thereon, a red pattern colored resin layer 96 was formed at the 
predetermined portion on the substrate with the respective intervals of 5 
.mu.m or less set from the blue colored resin layer and the green colored 
resin layer in the same manner as described above except for using as the 
third color a red colored resin material [photosensitive colored resin 
material prepared by dispersing Irgazine Red BPT (trade name, produced by 
Ciba-Geigy Co., C.I. No. 71127) in PA-1000 C (trade name, produced by Ube 
Kosan K.K., polymer content=10%, solvent: N-methyl-2-pyrrolidone, 
pigment:polymer=1:2)], thus obtaining a colored pattern of the three color 
stripes of R (red), G (green) and B (blue) (see FIG. 9E). 
Next, on the glass substrate having the colored pattern of the three colors 
formed thereon, as the light intercepting layer, a light intercepting 
layer 97 with a light intercepting pattern was formed in conformity with 
the gap between the respective units according to a method similar to that 
as described above by use of a black colored resin material 
[photosensitive colored resin material prepared by dispersing Carbon Black 
(C.I. No. 77266) in PA-1000 C (polymer content=10%, pigment:polymer=1:4)]. 
By this, the gap .alpha. (.mu.m) between the respective units could be 
made to fall within the range of 0.ltoreq..alpha..ltoreq.5 .mu.m. 
On the color filter pattern thus obtained, as the protective film or the 
flattening film 98, a film the same transparent resin material as used for 
the colored resin material [PA-1000 C (trade name, produced by Ube Kosan 
K.K., polymer content=10%, solvent: N-methyl-2-pyrrolidone)] was formed by 
the spinner coating method to a film thickness of about 0.5 .mu.m (see 
FIG. 9F). 
As described above, a flat color filter substrate could be formed. 
Next, as shown in FIG. 1, ITO film was formed according to the sputtering 
method to a thickness of 500 to form transparent electrode 15. The 
electrode was coated with a polyimide forming solution ("PIQ" produced by 
Hitachi Kasei Kogyo) by a spinner rotating at 3000 rpm, followed by 
heating at 150.degree. C. for 30 minutes to form a polyimide coating of 
2000 .ANG. as the alignment control film 17. Then, rubbing treatment was 
applied on the polyimide coating surface. 
The color filter substrate thus formed and confronting substrate 13 were 
adhered together to be assembled into a cell, and "CS-1014" (trade name) 
produced by Chisso K.K. which is a ferroelectric liquid crystal was 
injected therein and sealed to obtain a liquid crystal device. When the 
liquid crystal device was observed by means of a polarizing microscope of 
crossed Nicols, it was confirmed that no orientation defect was formed in 
the internal liquid crystal molecules. 
As described above, according to the present invention, there is no film 
thickness difference in the color filter layer on the substrate, and 
moreover the respective filter units are positioned within the interval 
.alpha.(.mu.m) in the range of 0.ltoreq..alpha..ltoreq.5 .mu.m, and 
further a light intercepting layer, a protective or flattening layer, if 
necessary, are provided, whereby it has become possible to remove even 
fine stepped differences occurring between the respective color filter 
units, and generation of alignment defect can be avoided to provide a 
ferroelectric liquid crystal device which can exhibit fully the 
characteristics of a ferroelectric liquid crystal. 
Additionally, according to the present invention, it has become possible to 
prepare a color filter portion having a fine pattern having also excellent 
mechanical strength as well as various excellent characteristics such as 
heat resistance, light resistance, solvent resistance, etc. according to 
simple preparation steps, whereby a color ferroelectric liquid crystal 
having excellent performances could be provided. 
Next, a cell was prepared according to entirely the same procedure as 
described above except that the interval .alpha. (.mu.m) between the color 
filter units was set at 8 .mu.m. As the result, alignment defects around 
the stepped portions of the color filters could be confirmed. 
EXAMPLE 2 
First, on #7059 glass substrate 91 produced by Corning was formed a colored 
resin layer 92 by coating of a blue colored resin material capable of 
obtaining desired spectral characteristics [the blue colored resin 
material being a photosensitive colored resin material prepared by 
dispersing Heliogen Blue L7080 (trade name, produced by BASF Co., C.I. No. 
74160) in PA-1000C (trade name, produced by Ube Kosan K.K., polymer 
content=10%, solvent: N-methyl pyrrolidone, pigment:polymer=1:2)] 
according to spinner coating to a film thickness of 1.5 .mu.m. 
Next, said colored resin layer, after prebaked at 80.degree. C. for 30 
minutes, was subjected to exposure by use of a high pressure mercury lamp 
through a photomask corresponding to the pattern shape to be formed. 
After exposure, the colored resin layer was developed by use of supersonic 
with an exclusive developer (comprising N-methyl-2-pyrrolidone as the main 
component) which dissolved only the unexposed portion of the colored resin 
layer having the photocured portion, and then the colored resin layer was 
treated with an exclusive rinse solution (e.g. a rinse solution comprising 
isopropyl alcohol as the main component), followed by post-baking at 
180.degree. C. for 30 minutes, to form a blue pattern colored resin layer 
having a pattern shape. 
Subsequently, on the glass substrate having a blue colored pattern formed 
thereon, a green pattern colored resin layer was formed at the 
predetermined portion on the substrate in the same manner as described 
above except for using as the second color a green colored resin material 
[photosensitive colored resin material prepared by dispersing Lionol Green 
6YK (trade name, produced by Toyo Ink, C.I. No. 74265) in PA-1000 C (trade 
name, produced by Ube Kosan K.K., polymer content=10%, solvent: 
N-methyl-2-pyrrolidone, pigment:polymer=1:2)]. 
Further, on the substrate having thus formed blue and green patterns 
thereon, a red pattern colored resin layer was formed at the predetermined 
portion on the substrate in the same manner as described above except for 
using as the third color a red colored resin material [photosensitive 
colored resin material prepared by dispersing Irgazine Red BPT (trade 
name, produced by Ciba-Geigy Co., C.I. No. 71127) in PA-1000 C (trade 
name, produced by Ube Kosan K.K. polymer content=10%, solvent: 
N-methyl-2-pyrrolidone, pigment:polymer=1:2)], thus obtaining a colored 
pattern of the three color stripes of R (red), G (Green) and B (blue) with 
the maximum film thickness difference of 0.1 .mu.m. 
Next, on the glass substrate having the colored pattern of the three colors 
formed thereon, as the light intercepting layer, a light intercepting 
layer with a light intercepting pattern was formed in conformity with the 
gap between the respective units according to the same method as described 
above by use of a black colored resin material [photosensitive colored 
resin material prepared by dispersing Carbon Black (C.I. No. 77266) in 
PA-1000 C (polymer content=10%, pigment:polymer=1:4)]. 
On the color filter pattern thus obtained, as the protective film or the 
flattening film, a film of the same transparent resin material as used for 
the colored resin material [PA-1000 C (trade name, produced by Ube Kosan 
K.K., polymer content=10%, solvent: N-methyl-2-pyrrolidone)]was formed by 
the spinner coating method to a film thickness of about 0.5 .mu.m. 
As described above, a flat color filter substrate could be formed. 
Next, as shown in FIG. 2, ITO film was formed according to the sputtering 
to a thickness of 500 .ANG. to form transparent electrode 15. The 
electrode was coated with a polyimide forming solution ("PIQ" produced by 
Hitachi Kasei Kogyo) by a spinner rotating at 3000 rpm, followed by 
heating at 150.degree. C. for 30 minutes to form a polyimide coating of 
2000 .ANG. as the alignment control film 17. Then, rubbing treatment was 
applied on the polyimide coating surface. 
The color filter substrate thus formed and confronting substrates 13 were 
adhered together to be assembled into a cell, and a ferroelectric liquid 
crystal was injected therein and sealed to obtain a liquid crystal device. 
When the liquid crystal device was observed by a polarizing microscope of 
crossed Nicols, it was confirmed that no orientation defect was formed in 
the internal liquid crystal molecules. 
Next, a cell was prepared according to entirely the same procedure as 
described above except that the maximum film thickness difference was set 
at 0.3 .mu.m. As the result, alignment defects around the stepped 
difference portions of the color filters could be confirmed. 
EXAMPLE 3 
FIGS. 10A-10G are the diagrams of the steps showing an example of the 
formation steps of the color units of color filters of the three colors of 
R, G and B. 
This Example describes about the case by use of a color filter formed by 
repeating the photolithographic step of a colored resin comprising a 
colorant material dispersed in polyamide having photosensitive group in 
the molecule, which is the excellent system in which the film thickness of 
the respective color units can be made substantially constant by setting 
previously the concentration of the colorant materials and fine patterns 
can be formed by a simple preparation process, and which is further 
excellent in mechanical characteristics and also in various excellent 
characteristics such as heat resistance, light resistance, solvent 
resistance, etc. 
First, on #7059 glass substrate 101 produced by Corning was formed a 
colored resin layer 102 by coating of a blue colored resin material 
capable of obtaining desired spectral characteristics [the blue colored 
material being a photosensitive colored resin material prepared by 
dispersing Heliogen Blue L7080 (trade name, produced by BASF Co., C.I. No. 
74160) in PA-1000C (trade name, produced by Ube Kosan K.K., polymer 
content=10%, solvet: N-methyl pyrrolidone, pigment:polymer=1:2)] according 
to spinner coasting to a film thickness of 1.5 .mu.m (see FIG. 10A). 
Next, said colored resin layer 102, after prebaked at 80.degree. C. for 30 
minutes, was subjected to exposure by use of a high pressure mercury lamp 
through a photomask 103 corresponding to the pattern shape to be formed 
(see FIG. 10B). 
After exposure, as shown in FIG. 10C, the layer 102 was developed by use of 
supersonic with an exclusive developer (comprising N-methyl-2-pyrrolidone 
as the main component) which dissolved only the unexposed portion of the 
colored resin layer 102 having the photocured portion 102a, and then the 
layer was treated with an exclusive rinse solution (e.g. a rinse solution 
comprising isopropyl alcohol as the main component), followed by 
post-baking at 150.degree. C. for 30 minutes, to form a blue pattern 
colored resin layer 104 having a pattern shape (see FIG. 10D). 
Subsequently, on the glass substrate having a blue colored pattern formed 
thereon, a green pattern colored resin layer 105 was formed at the 
predetermined portion on the substrate in the same manner as described 
above except for using as the second color a green colored resin material 
[photosensitive colored resin material prepared by dispersing Lionol Green 
6YK (trade name, produced by Toyo Ink, C.I. No. 74265) in PA-1000 C (trade 
name, produced by Ube Kosan K.K., polymer component=10%, solvent: 
N-methyl-2-pyrrolidone, pigment:polymer=1:2(]. 
Further, on the substrate having thus formed blue and green patterns 
thereon, a red pattern colored resin layer 106 was formed at the 
predetermined portion on the substrate in the same manner as described 
above except for using as the third color a red colored resin material 
[photosensitive colored resin material prepared by dispersing Irgazine Red 
BPT (trade name, produced by Ciba-Geigy Co., C.I. 
No. 71127) in PA-1000 C (trade name, produced by Ube Kosan K.K. polymer 
component=10%, solvent: N-methyl-2-pyrrolidone, pigment:polymer=1:2)], 
thus obtaining a colored pattern of the three color stripes of R (red), G 
(green) and B (blue) (see FIG. 10E). 
Next, on the glass substrate having the colored pattern of the three colors 
formed thereon, as the light intercepting layer, a light intercepting 
layer 107 with a light intercepting pattern was formed in conformity with 
the gap between the respective picture elements according to the same 
method as described above by use of a black colored resin material 
[photosensitive colored resin material prepared by dispersing Carbon Black 
(C.I. No. 77266) in PA-1000 C (polymer component=10%, 
pigment:polymer=1:4)]. 
On the color filter pattern thus obtained, the first transparent resin 
layer 108 was formed by applying a photosensitive polyamide resin solution 
previously controlled to have a viscosity of 50 cps [PA-1000 C (trade 
name, produced by Ube Kosan K.K., solvent: N-methyl-2-pyrrolidone)] 
according to the spinner coating method to a film thickness of about 0.5 
.mu.m (see FIG. 10F). 
Prebaking (70.degree. C. for 20 minutes), exposure, developing, rinsing and 
post-baking (150.degree. C. for 30 minutes) treatments were conducted to 
form a flattened layer, and then on said transparent resin layer 108 was 
formed, as the second transparent resin layer 109, a film of a 
photosensitive polyamide resin solution previously controlled to have a 
viscosity of 100 cps [PA-1000C (trade name, produced by Ube Kosan K.K., 
solvent: N-methyl-2-pyrrolidone)] by the spinner coating method to a film 
thickness of about 1 .mu.m (see FIG. 10G). 
Prebaking (70.degree. C. for 20 minutes), exposure, developing, rinsing, 
post-baking (150.degree. C. for 30 minutes) treatments were conducted to 
form a protective film. 
As described above, a flat color filter substrate could be formed. 
Next, as shown in FIG. 3, ITO film was formed according to the sputtering 
method to a thickness of 500 .ANG. to form transparent electrode 15. The 
electrode was coated with a polyimide forming solution ("PIQ" produced by 
Hitachi Kasei Kogyo) by a spinner rotating at 3000 rpm, followed by 
heating at 150.degree. C. for 30 minutes to form a polyimide coating of 
2000 .ANG. as the alignment control film 17. Then, rubbing treatment was 
applied on the polyimide coating surface. 
The color filter substrate thus formed and confronting substrates 13 were 
adhered together to be assembled into a cell, and a ferroelectric liquid 
crystal was injected therein and sealed to obtain a liquid crystal device. 
When the-liquid crystal device was observed by means of a polarizing 
microscope of crossed Nicols, it was confirmed that no orientation defect 
was formed in the internal liquid crystal molecules. 
As described above, according to the present invention, even when there is 
difference in film thickness of the color filter layers on the substrate, 
by laminating successively a first transparent resin layer formed of a 
lower viscosity resin which brings about flattening on said color filter 
layers and a second transparent resin layer formed of a higher viscosity 
resin which brings about flattening and protection, it becomes possible to 
remove fine stepped differences in film thickness difference occurring 
between the respective color filter units or stepped difference in the 
respective unit intervals, whereby generation of alignment defect can be 
avoided to provide a ferroelectric liquid crystal device capable of 
exhibiting fully the characteristics of a ferroelectric liquid crystal. 
Next, a cell was prepared according to entirely the same procedure as 
described above except for omitting use of the first transparent resin 
film and the second transparent resin film. As the result, alignment 
defects around the stepped difference portions of the color filters could 
be confirmed. 
EXAMPLE 4 
FIGS. 11A-11G are the diagrams of the steps showing the formation steps of 
the color units of the three colors of R, G and B. 
First, on #7059 glass substrate 111 produced by Corning was formed a 
colored resin layer 112 by coating of a blue colored resin material 
capable of obtaining desired spectral characteristics [the blue colored 
resin material being a photosensitive colored resin material prepared by 
dispersing Heliogen Blue L7080 (trade name, produced by BASF Co., C.I. No. 
74160) in PA-1000C (trade name, produced by Ube Kosan K.K., polymer 
content=10%, solvent: N-methyl pyrrolidone, pigment:polymer=1:2)] 
according to spinner coating to a film thickness of 1.5 .mu.m (see FIG. 
11A). 
Next, said colored resin layer 112, after prebaked at 80.degree. C. for 30 
minutes, was subjected to excess exposure by use of a high pressure 
mercury lamp through a photomask 113 corresponding to the pattern shape to 
be formed (see FIG. 11B). 
After exposure, as shown in FIG. 11C, the layer 112 was developed by use of 
supersonic with an exclusive developer (comprising N-methyl-2-pyrrolidone 
as the main component) which dissolved only the unexposed portion of the 
colored resin layer 102 having the photocured portion 102a, and the layer 
112 was treated with an exclusive rinse solution (e.g. a rinse solution 
comprising isopropyl alcohol as the main component), followed by 
post-baking at 150.degree. C. for 30 minutes, to form a blue pattern 
colored resin layer 114 having a tapered shape (angle=15.degree.) at the 
end of the trapezoidal shape (see FIG. 11D). 
Subsequently, on the glass substrate having a blue colored pattern formed 
thereon, a green pattern colored resin layer 115 was formed, partially 
overlapping with the blue pattern shape colored resin layer (overlapping 
width w=5 .mu.m) at the predetermined portion on the substrate in the same 
manner as described above except for using as the second color a green 
colored resin material [ photosensitive colored resin material prepared by 
dispersing Lionol Green 6YK (trade name, produced by Toyo Ink, C.I. No. 
74265) in PA-1000 C (trade name, produced by Ube Kosan K.K., polymer 
content=10%, solvent: N-methyl-2-pyrrolidone, pigment:polymer=1:2). 
Further, on the substrate having thus formed blue and green patterns 
thereon, a red pattern colored resin layer 116 was formed, partially 
overlapping with the blue pattern colored resin layer and the green 
pattern colored resin layer (overlapping width w=5 .mu.m) at the 
predetermined portion on the substrate in the same manner as described 
above except for using as the third color a red colored resin material [ 
photosensitive colored resin material prepared by dispersing Irgazine Red 
BPT (trade name, produced by Ciba-Geigy Co., C.I. No. 71127) in PA-1000 C 
(trade name, produced by Ube Kosan K.K., polymer content=10%, solvent: 
N-methyl-2-pyrrolidone, pigment:polymer=1:2), thus obtaining a colored 
pattern of the three color stripes of R (red), G (green) and B (blue) (see 
FIG. 11E). 
Next, on the glass substrate having the colored pattern of the three colors 
formed thereon, as the light intercepting layer, a light intercepting 
layer 117 with a light intercepting pattern was formed in conformity with 
the gap between the respective units according to the same method as 
described above by use of a black colored resin material [ photosensitive 
colored resin material prepared by dispersing Carbon Black (C.I. No. 
77266) in PA-1000 C (polymer content=10%, pigment:polymer=1:4)]. 
On the color filter pattern thus obtained, as the protective film or 
flattening film 118, a film of the same transparent resin material as used 
for the colored resin material [PA-1000 C (trade name, produced by Ube 
Kosan K.K., polymer content=10%, solvent: N-methyl-2-pyrrolidone)] was 
formed by the spinner coating method to a film thickness of about 1.0 
.mu.m (see FIG. 11F). 
As described above, a flat color filter substrate could be formed. 
Next, as shown in FIG. 4, ITO film was formed according to the sputtering 
method to a thickness of 500 .ANG. to form transparent electrode 15. The 
electrode was coated with a polyimide forming solution ("PIQ" produced by 
Hitachi Kasei Kogyo) by a spinner rotating at 3000 rpm, followed by 
heating at 150.degree. C. for 30 minutes to form a polyimide coating of 
2000 .ANG. as the alignment control film 17. Then, rubbing treatment was 
applied on the polyimide coating surface. 
The color filter substrate thus formed and confronting substrate 13 were 
adhered together to be assembled into a cell, and a ferroelectric liquid 
crystal was injected therein and sealed to obtain a liquid crystal device. 
When the liquid crystal device was observed by a polarizing microscope of 
crossed Nicols, it was confirmed that no orientation defect was formed in 
the internal liquid crystal molecules. 
As described above, according to the present invention, by setting a 
tapered angle at the range of 0.degree. to 90.degree. to the color filter 
picture elements on the substrate and providing overlapping portions 
between the adjacent units in the range of 0 to [d (film thickness)/tan 
.theta.(tapered angle)], the stepped difference in the unit interval can 
be alleviated to 1/2 at the maximum as compared with conventional unit 
pattern, and even in the case when there is unit deviation caused by 
alignment stepped difference during unit formation, the stepped difference 
caused thereby can be reduced to 1/2 of the conventional case, whereby 
generation of alignment defect can be avoided to provide a ferroelectric 
liquid crystal device capable of exhibiting fully the characteristics of a 
ferroelectric liquid crystal. 
EXAMPLE 5 
FIGS. 12A-12G are diagrams of steps showing a first formation step 
including the three color filter layers and a heat-fusible resin layer. 
First, on #7059 glass substrate 121 produced by Corning Co., the 
heat-fusible resin layer 125 was formed by applying a methyl acetate 
solution of an ethylene-vinyl acetate copolymer at a layer thickness of 
1.0 .mu.m by use of a spinner. Then, the layer 125 was coated with a 
positive-type resist (trade name: OFPR 77, produced by Tokyo Oka) at a 
layer thickness of 1.0 .mu.m by use of a spinner to provide a resist layer 
122 (see FIG. 12A). Next, by use of a predetermined pattern mask, the 
resist layer was exposed to light (see FIG. 12B) and developed with an 
ODUR 1010 series exclusive developer to form a resist pattern 122a for 
lift-off having a predetermined stripe shape (see FIG. 12C). 
Next, the whole surface of the pattern-formed surface of the glass 
substrate 121 was exposed to light, and further unnecessary resist residue 
other than the pattern portion was removed from the glass substrate 121 by 
oxygen plasma ashing treatment. 
The glass substrate 121 having thus the pattern 122a for lift-off formed 
thereon was arranged at a predetermined position in a vacuum vapor 
deposition apparatus, nickel phthalocyanine was placed as the blue dye for 
vapor deposition in the molybdenum boat as the vaporization source, and a 
colored layer 124 was formed by vapor deposition of nickel phthalocyanine 
to a thickness of 4500 .ANG. on the pattern formed surface for lift-off by 
controlling the vaporization temperature of the former to 470.degree. C. 
(see FIG. 12D). 
The substrate 121 having the pattern 122a and the colored layer 124 formed 
thereon was dipped for 5 minutes and stirred in an OFPR 77 series 
exclusive developer to remove the colored layer 124a vapor deposited on 
the pattern together with the resist pattern, whereby a blue color stripe 
filter was prepared (see FIG. 12E). 
On the other hand, green and red stripe filters were obtained by repeating 
the steps of FIGS. 12A-12E. First, as the green dye for vapor deposition, 
lead phthalocyanine was vapor-deposited to a thickness of 5000 .ANG. to 
form a green layer. 
Next, as the red de for vapor deposition, anthraquinone was vapor-deposited 
to a thickness of 3000 .ANG. to form a red layer. 
As described above, color filters of B, G and R could be formed as shown in 
FIG. 12F. 
Next, after the color filters containing the heat-fusible resin layer were 
subjected to hot press at about 150.degree. C. to embed the heat-fusible 
resin in the gaps between the color filter units, the temperature was 
returned to room temperature to form a layer binding color filters (see 
FIG. 12G). 
Next, as the protective film 19, a negative resist (ODUR, produced by Tokyo 
Oka) was formed by coating. At this stage, the color filter substrate is 
formed on entirely the same plane. 
Next, as shown in FIG. 5, ITO film was formed according to the sputtering 
method to a thickness of 500 .ANG. to form transparent electrode 15. The 
electrode was coated with a polyimide forming solution ("PIQ" produced by 
Hitachi Kasei Kogyo) by a spinner rotating at 3000 rpm, followed by 
heating at 150.degree. C. for 30 minutes to form a polyimide coating of 
2000 .ANG. as the alignment control film 17. Then, rubbing treatment was 
applied on the polyimide coating surface. 
The color filter substrate thus formed and confronting substrate 13 were 
adhered together to be assembled into a cell, and a ferroelectric liquid 
crystal was injected therein and sealed to obtain a liquid crystal device. 
When the liquid crystal device was observed by a polarizing microscope of 
crossed Nicols, it was confirmed that no orientation defect was formed in 
the internal liquid crystal molecules. 
EXAMPLE 6 
FIGS. 13A-13G are the diagrams of the steps showing the second step 
including the color filter layers of the three colors of R, G and B and 
the heat-fusible resin layer. 
First, on #7059 glass substrate 131 produced by Corning was formed a 
colored resin layer 132 by coating of a blue colored resin material 
capable of obtaining desired spectral characteristics [the blue colored 
resin material being a photosensitive colored resin material prepared by 
dispersing Heliogen Blue L7080 (trade name, produced by BASF Co., C.I. No. 
74160) in PA-1000C (trade name, produced by Ube Kosan K.K., polymer 
content=10%, solvent: N-methyl pyrrolidone, pigment:polymer=1:2)] 
according to spinner coating to a film thickness of 1.5 .mu.m (see FIG. 
13A). 
Next, said colored resin layer 132, after prebaked at 80.degree. C. for 30 
minutes, was subjected to exposure by use of a high pressure mercury lamp 
through a photomask 133 corresponding to the pattern shape to be formed 
(see FIG. 13B). 
After exposure, as shown in FIG. 13C, the layer 132 was developed by use of 
supersonic with an exclusive developer comprising N-methyl-2-pyrrolidone 
as the main component) which dissolved only the unexposed portion of the 
colored resin layer 132 having the photocured portion 132a, and then the 
layer 132 was treated with an exclusive rinse solution (e.g. a rinse 
solution comprising isopropyl alcohol as the main component), followed by 
post-baking at 150.degree. C. for 30 minutes, to form a blue pattern 
colored resin layer 134 having a pattern shape (see FIG. 13D). 
Subsequently, on the glass substrate having a blue colored pattern formed 
thereon, a green pattern colored resin layer 135 was formed at the 
predetermined position on the substrate in the same manner as described 
above except for using as the second color a green colored resin material 
[photosensitive colored resin material prepared by dispersing Lionol Green 
6YK (trade name, produced by Toyo Ink, C.I. No. 74265) in PA-1000 C (trade 
name, produced by Ube Kosan K.K., polymer content=10%, solvent: 
N-methyl-2-pyrrolidone, pigment:polymer=1:2)]. 
Further, on the substrate having thus formed blue and green patterns 
thereon, a red pattern colored resin layer 136 was formed at the 
predetermined position on the substrate in the same manner as described 
above except for using as the third color a red colored resin material 
[photosensitive colored resin material prepared by dispersing Irgazin Red 
BPT (trade name, produced by Ciba-Geigy Co., C.I. No. 71127) in PA-1000 C 
(trade name, produced by Ube Kosan K.K., polymer content=10%, solvent: 
N-methyl-2-pyrrolidone, pigment:polymer=1:2), thus obtaining a colored 
pattern of the three color stripes of R (red), G (green) and B (blue) (see 
FIG. 13E)]. 
Next, the color filter obtained was coated with a methyl acetate solution 
of an ethylene-vinyl acetate copolymer resin at a layer thickness of 1.5 
.mu.m by use of a spinner, and the coated product was subjected to hot 
press at about 150.degree. C. to embed the heat-fusible resin 137 in the 
gaps between the color filter units, followed by cooling to normal 
temperature to form a layer binding color filters (see FIG. 13F). 
On the color filter pattern thus obtained, as the protective film or 
flattening film 138, a film of the same transparent resin material as used 
for the colored resin material [PA-1000 C (trade name, produced by Ube 
Kosan K.K., polymer content=10%, solvent: N-methyl-2-pyrrolidone)] as 
formed by the spinner coating method to a film thickness of about 0.5 
.mu.m (see FIG. 13F). 
As described above, a color filter substrate made on the same plane could 
be formed. 
Next, as shown in FIG. 5, ITO film was formed according to the sputtering 
method to a thickness of 500 .ANG. to form transparent electrode 15. The 
electrode was coated with a polyimide forming solution ("PIQ" produced by 
Hitachi Kasei Kogyo) by a spinner rotating at 3000 rpm, followed by 
heating at 150.degree. C. for 30 minutes to form a polyimide coating of 
2000 .ANG. as the alignment control film 17. Then, rubbing treatment was 
applied on the polyimide coating surface. 
The color filter substrate thus formed and confronting substrates 13 were 
adhered together to be assembled into a cell, and a ferroelectric liquid 
crystal was injected therein and sealed to obtain a liquid crystal device. 
When the liquid crystal device was observed by a polarizing microscope of 
crossed Nicols, it was confirmed that no orientation defect was formed in 
the internal liquid crystal molecules. 
As described above, according to the present invention, since the 
difference in film thickness between the color filter layers and the gaps 
between the color filter units are filled with a heat-fusible resin, great 
stepped difference does not occur, and further by providing a protective 
or flattening film as desired, it becomes also possible to remove fine 
stepped difference occurring between the respective units of color 
filters, whereby generation of alignment defect could be avoided to 
provide a ferroelectric liquid crystal device capable of exhibiting fully 
the characteristics of a ferroelectric liquid crystal. 
Next, a cell was prepared in the same manner as described above except for 
omitting use of the heat-fusible resin film. As the result, alignment 
defects could be confirmed at the color filter stepped difference 
portions. 
EXAMPLE 7 
FIGS. 14A-14G are the diagrams of the steps showing the formation steps of 
the color units of the three colors of R, G and B. 
First, on #7059, glass substrate 141 was formed a colored resin layer 142 
by coating of a blue colored resin material capable of obtaining desired 
spectral characteristics [the blue colored resin material being a 
photosensitive colored resin material prepared by dispersing Heliogen Blue 
L7080 (trade name, produced by BASF Co., C.I. No. 74160) in PA-1000C 
(trade name, produced by Ube Kosan K.K., polymer content=10%, solvent: 
N-methyl pyrrolidone, pigment:polymer=1:2)] according to spinner coating 
to a film thickness of d .mu.m (see FIG. 14A). 
Next, said colored resin layer 142, after prebaked at 70.degree. C. for 30 
minutes, was subjected to exposure by use of a high pressure mercury lamp 
through a photomask 143 corresponding to the pattern shape to be formed 
(see FIG. 14B). 
After exposure, as shown in FIG. 14C, the layer 142 was developed by use of 
supersonic with an exclusive developer (the developer comprising 
N-methyl-2-pyrrolidone as the main component) which dissolved only the 
unexposed portion of the colored resin layer 142 having the photocured 
portion 142a, and then the layer 142 was treated with an exclusive rinse 
solution (e.g. a rinse solution comprising isopropyl alcohol as the main 
component), followed by post-baking at 200.degree. C. for 30 minutes, to 
form a blue pattern colored resin layer 144 having a pattern shape (see 
FIG. 14D). 
Subsequently, on the glass substrate having a blue colored pattern formed 
thereon, a green pattern colored resin layer 145 was formed with a unit 
interval from the blue colored pattern as a measured value l (.mu.m) on 
the substrate in the same manner as described above by using as the second 
color a green colored resin material [photosensitive colored resin 
material prepared by dispersing Lionol Green 6YK (trade name, produced by 
Toyo Ink, C.I. No. 74265) in PA-1000 C (trade name, produced by Ube Kosan 
K.K., polymer content=10%, solvent: N-methyl-2-pyrrolidone, 
pigment:polymer=1:2)]. 
Further, on the substrate having thus formed blue and green patterns 
thereon, a red pattern colored resin layer 136 was formed with a unit 
interval from the blue and the green colored patterns as a measured value 
l (.mu.m) at the predetermined position on the substrate in the same 
manner as described above except for using as the third color a red 
colored resin material [photosensitive colored resin material prepared by 
dispersing Irgazin Red BPT (trade name, produced by Ciba-Geigy Co., C.I. 
No. 71127) in PA-1000 C (trade name, produced by Ube Kosan K.K., polymer 
content=10%, solvent: N-methyl-2-pyrrolidone, pigment:polymer=1:2)], thus 
obtaining a colored pattern of the three color stripes of R (red), G 
(green) and B (blue) (see FIG. 14E). 
Next, on the glass substrate having the colored pattern of the three colors 
formed thereon, as the light intercepting layer, a light intercepting 
layer 147 with a light intercepting pattern was formed in conformity with 
the gap between the respective units according to a procedure similarly to 
that as described above by use of a black colored resin material 
[photosensitive colored resin material prepared by dispersing Carbon Black 
(C.I. No. 77266) in PA-1000 C (polymer content=10%, pigment:polymer=1:4)]. 
On the color filter pattern thus obtained, as the protective film or 
flattening film 148, a film of the same transparent resin material as used 
for the colored resin material [PA-1000 C (trade name, produced by Ube 
Kosan K.K., polymer content=10%, solvent: N-methyl-2-pyrrolidone)] was 
formed by the spinner coating method to a film thickness of about 0.5 
.mu.m (see FIG. 14F). 
Next, as shown in FIG. 6, ITO film was formed according to the sputtering 
method to a thickness of 500 .ANG. to form transparent electrode 15. The 
electrode was coated with a polyimide forming solution ("PIQ" produced by 
Hitachi Kasei Kogyo) by a spinner rotating at 3000 rpm, followed by 
heating at 150.degree. C. for 30 minutes to form a polyimide coating of 
2000 .ANG. as the alignment control film 17. Then, rubbing treatment was 
applied on the polyimide coating surface. 
The color filter substrate thus formed and confronting substrate 13 were 
adhered together to be assembled into a cell, and "CS-1014" (trade name) 
produced by Chisso K.K. which is a ferroelectric liquid crystal was 
injected therein and sealed to obtain a liquid crystal device. When the 
liquid crystal device was observed by a polarizing microscope of crossed 
Nicols, and the extent of alignment defect of the internal liquid crystal 
molecules was evaluated. 
In the above method, the film thickness d (.mu.m) of color filter and the 
distance l (.mu.m) between the respective units of color filters were 
varied for evaluation of alignment defects to obtain the results shown in 
Table 1. 
TABLE 1 
______________________________________ 
Test 1 Test 2 Test 3 Test 4 Test 5 
______________________________________ 
d (.mu.m) 
0.9 1.0 1.5 1.5 2.1 
l (.mu.m) 
5.2 4.7 5.0 9.0 11.0 
l/d 5.8 4.7 3.3 6.0 5.2 
Alignment 
.DELTA. O O X .DELTA. 
defect state 
______________________________________ 
Note 
(1)The values of d and l are those measured. 
(2)Evaluation of alignment defect state: The symbol O means the state fre 
substantially from any problem. The symbol .DELTA. means the state that 
slight defects are recognized. The symbol X means the state that 
remarkable defects are recognized. 
As described above, according to the present invention, by setting the 
intervals between the respective units of the color filters on the 
substrate at 5-fold or less of the film thickness, it has become possible 
to reduce remarkably the alignment defect caused by the stepped difference 
between the units. 
Also, by providing a light intercepting layer, a protective or flattening 
layer on the color filter as desired, it has become possible to alleviate 
sufficiently the stepped difference occurring between the respective units 
of the color filter, whereby generation of alignment defect could be 
avoided to provide a ferroelectric liquid crystal device capable of 
exhibiting fully the characteristics of a ferroelectric liquid crystal.