Liquid crystal display device with polymer wall formation rate in peripheral region of display section at least 90%

The liquid crystal display device of this invention, includes: a pair of substrates, at least one of which is transparent; and a liquid crystal layer including a plurality of polymer walls and liquid crystal regions surrounded by the plurality of polymer walls and being interposed between the pair of substrates, wherein each substrate includes a display section having a plurality of electrodes for display at a side adjacent to the liquid crystal layer and a non-display section provided around the display section, and wherein a polymer wall formation rate in the peripheral region of the display section is 90% or more.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a liquid crystal device which can be used, 
for example, in a portable information terminal having a pen based input, 
OA equipment such as a television, or a display having a wide viewing 
angle, and to a method for producing the same. More particularly, the 
present invention relates to a liquid crystal display device including a 
liquid crystal region surrounded by a polymer wall which operates a 
twisted nematic (TN) mode, a super twisted nematic (STN) mode, an 
electrically controlled birefringence (ECB) mode, a ferroelectric liquid 
crystal (FLC) display mode, a light scattering mode or the like; and a 
method for producing the same. 
2. Description of the Related Art 
Nowadays, various kinds of display modes have been employed for a liquid 
crystal display (LCD) device. For example, LCDs for providing a display in 
a twisted nematic (TN) mode or a super twisted nematic (STN) mode using 
nematic liquid crystal molecules are practically used as LCDs utilizing 
electrooptic characteristics for performing a display. In addition, LCDs 
utilizing ferroelectric liquid crystal material can be put into practical 
use. 
Moreover, a mode for electrically controlling a transparent state and a 
scattering state of a liquid crystal material by the use of birefringence 
of the liquid crystal material has recently been proposed in, for example, 
Japanese Laid-Open National Patent Publication No. 58-501631. In an LCD 
operating in accordance with this mode, a display medium in which liquid 
crystal droplets are dispersed in a polymer is interposed between a pair 
of substrates opposed to each other. This type of LCD is called a polymer 
dispersed liquid crystal (PDLC) display device. In a PDLC display device, 
a display is performed in the following manner. When a voltage is applied 
to the liquid crystal layer, the orientations of the liquid crystal 
molecules are aligned towards the direction of the electric field. As a 
result, the ordinary refractive index of the liquid crystal molecules is 
matched with the refractive index of the polymer serving as a support 
medium, whereby a transparent state is obtained. On the other hand, when 
no voltage is applied to the liquid crystal layer, the random orientations 
of the liquid crystal molecules cause light scattering, whereby an opaque 
state is obtained. By controlling orientations of liquid crystal molecules 
between the transparent state and the opaque state, display can be 
performed. 
According to a method for producing the above-mentioned PDLC display 
device, the liquid crystal droplets are formed by utilizing the 
phase-separation between the polymer and the liquid crystal material. 
Thus, the shapes and size of the liquid crystal droplets are not uniform, 
and it is difficult to precisely control arrangements of the liquid 
crystal droplets in a direction along the surface of the substrates. 
Consequently, different driving voltages are required to be applied to the 
respective liquid crystal droplets to degrade the steepness of the 
threshold value exhibiting the electrooptic characteristics, resulting in 
a relatively high driving voltage. 
In order to solve the problems of the above-mentioned conventional PDLC 
display device, Japanese Laid-Open Patent Publication No. 6-301015 
assigned to the same assignee of the present application discloses a new 
display mode using an improved PDLC display device. In preparation of this 
LCD, ultraviolet rays are radiated onto the mixture of a liquid crystal 
material and a photopolymerizable compound through a photomask and the 
like so that some regions are irradiated with relatively intense light and 
other regions are irradiated with relatively weak light. As a result, the 
polymer is aggregated in the regions irradiated with the relatively 
intense light to form polymer walls, while the liquid crystal material is 
aggregated in the regions irradiated with the relatively weak light to 
form a liquid crystal region. According to this method, liquid crystal 
droplets can be uniformly formed in shape and size. Also, it is possible 
to precisely control the arrangement of liquid crystal droplets, i.e., 
pixels, in a direction along a surface of the substrate. 
In the above-mentioned liquid crystal display device, the substrate 
includes: a display section in which transparent electrodes made of a 
material for reducing the amount of UV rays to be transmitted such as ITO 
(Indium Tin Oxide) is formed; and a terminal section (a non-display 
section) formed around the display section. Polymer walls are formed 
between the adjacent transparent electrodes, and between transparent 
electrodes of two opposed substrates and the terminal region. An 
overlapped region of the electrodes formed on the substrates opposed to 
each other serves as a pixel. Typically, a distance between the pixel in 
the periphery of the display section and the end portion of the substrate 
is larger than that between pixels in the display section. Therefore, in 
the boundary region between the display section and the non-display 
section, there are necessarily some large UV ray irradiated areas and 
other smaller UV irradiated areas. For example, in the corner of the 
display section, a distance between the pixel present at the corner and 
the pixel adjacent thereto is smaller than a distance between these pixels 
and the end portion of the substrate. Therefore, the area irradiated with 
UV rays in the latter case is larger than that in the former case. 
Generally, the polymerization of the photopolymerizable compound occurs 
more easily in the large area irradiated with UV rays than in the small 
area. Thus, the polymerization more rapidly proceed in the region between 
the end portion of the substrate than in the region between pixels in the 
boundary region between the display section and the non-display section. 
With the polymerization of photopolymerizable compounds, since a large 
amount of the photopolymerizable compound is converted to a polymer in the 
region between the pixel and the end portion of the substrate, 
photopolymerizable compounds migrate from the region between pixels to the 
region between the pixel and the end portion of the substrate, decreasing 
a concentration of the polymerizable compound in the region between 
pixels. Furthermore, some polymers produced in the region between pixels 
also migrate from the region between pixels to the region between the 
pixel and the end portion of the substrate, resulting in poor formation of 
polymer walls in the region between pixels. 
As a result, a ratio of polymer walls and liquid crystal regions in the 
peripheral region of the display section differs from that in the central 
region of the display section. The amount of light transmitted through the 
liquid crystal region and the polymer wall, which have different 
refractive indices, in the peripheral region of the display section 
differs from that in the central region of the display section. In this 
way, since the amount of transmitted light in the peripheral region of the 
display section differs from that in the central region of the display 
section, the tone obtained in the peripheral region is different from that 
obtained in the central region. Thus, a conventional liquid crystal 
display device is disadvantageous in that it is difficult to obtain 
uniform display over the entire display region. 
Japanese Laid-Open Patent Publication Nos. 61-215524 and 63-137213 disclose 
a method for increasing the reliability of a panel by adhering a pair of 
substrates using a two-layered structure sealing material or for enhancing 
the panel strength so as to reduce unevenness of a gap between the 
substrates. However, the above-mentioned sealing material having the 
two-layered structure has not been used for the purpose of enhancing 
display quality of a liquid crystal display device by preventing migration 
of photopolymerizable compounds and polymers from the region between 
pixels to the region between the pixel and the end portion of the 
substrate. 
SUMMARY OF THE INVENTION 
The liquid crystal display device of this invention, includes: a pair of 
substrates, at least one of which is transparent; and a liquid crystal 
layer including a plurality of polymer walls and liquid crystal regions 
surrounded by the plurality of polymer walls and being interposed between 
the pair of substrates, wherein each substrate includes a display section 
having a plurality of electrodes for display at a side adjacent to the 
liquid crystal layer and a non-display section provided around the display 
section, and wherein a polymer wall formation rate in the peripheral 
region of the display section is 90% or more. 
In a preferred embodiment of this invention, a shielding layer for reducing 
the amount of UVs ray to be transmitted is provided on at least one 
surface of at least one substrate in the non-display section. 
In a preferred embodiment of this invention, a sealing material is provided 
on a non-display section side in a boundary region between the display 
section and the non-display section. 
In a preferred embodiment of this invention, the sealing material has a 
double structure having an inner seal and an outer seal, the inner seal is 
provided in the boundary region between the display section and the 
non-display section, and the outer seal is provided in the non-display 
section. 
In a preferred embodiment of this invention, a liquid crystal material is 
injected between the inner seal and the outer seal. 
In a preferred embodiment of this invention, a width of the inner seal is 
the range of 50 .mu.m to 2 mm. 
In a preferred embodiment of this invention, a plurality of further 
electrodes having a shape similar to those formed in the display section 
are formed in the non-display section. 
In a preferred embodiment of this invention, the electrodes are formed in 
at least three pixel rows. 
The method for producing a liquid crystal display device includes the steps 
of: attaching a pair of substrates, at least one of which is transparent, 
to each other, each substrate including a display section having a 
plurality of electrodes for display and a non-display section provided 
around the display section so that surfaces of the substrates on which the 
electrodes are respectively formed face each other; sealing a mixture of a 
photopolymerizable composition and a liquid crystal material between the 
pair of substrates; irradiating the mixture with light having different 
irradiation intensity between the display section and the non-display 
section and significantly varying irradiation intensity in the display 
section to photopolymerize the mixture so as to form polymer walls and 
liquid crystal regions. 
In a preferred embodiment of this invention, a shielding layer for reducing 
the amount of UV light to be transmitted is provided on at least one 
surface of at least one substrate in the non-display section. 
In a preferred embodiment of this invention, a sealing material is provided 
on the non-display section side in a boundary region between the display 
section and the non-display section. 
In a preferred embodiment of this invention, the sealing material has a 
double structure having an inner seal and an outer seal, the inner seal is 
provided in the boundary region between the display section and the 
non-display section, and the outer seal is provided in the non-display 
section. 
In a preferred embodiment of this invention, a liquid crystal material is 
injected between the inner seal and the outer seal. 
In a preferred embodiment of this invention, a width of the inner seal is 
the range of 50 .mu.m to 2 mm. 
In a preferred embodiment of this invention, a plurality of further 
electrodes having a shape similar to those formed in the display section 
are formed in the non-display section. 
In a preferred embodiment of this invention, the electrodes are formed in 
at least three pixel rows. 
Thus, the invention described herein makes possible the advantages of: (1) 
providing a liquid crystal display device with reduced unevenness of tone 
by reducing poor formation of polymer walls over the entire display 
section to improve display quality; and (2) providing a method for 
producing a liquid crystal display device capable of reducing poor 
formation of polymer walls over the entire display section so as to reduce 
evenness of tone and improve display quality. 
These and other advantages of the present invention will become apparent to 
those skilled in the art upon reading and understanding the following 
detailed description with reference to the accompanying figures.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Hereinafter, examples of the present invention will be described with 
reference to FIGS. 1 through 5. However, the present invention is not 
limited thereto. In the present specification, the term "a liquid crystal 
region" refers to a space which includes a liquid crystal material and is 
surrounded by a polymeric material. 
The term "a polymer wall" refers to a polymeric material which separates a 
liquid crystal region from neighboring liquid crystal regions. 
The term "polymer wall formation rate" refers to a ratio of pixels where 
four contiguous polymer walls surrounding a pixel are successively formed 
to all pixels in three pixel rows at the peripheral region of the display 
section A. 
The term "pixel row" refers to an arrangement of pixels along the boundary 
region between the display section and non-display section. The first 
pixel row is adjacent to the boundary region, the second pixel row is 
neighboring to the first pixel row and the third pixel row is neighboring 
to the second row. When pixel rows are in the display section, the third 
pixel row includes the nearest pixel to a center of the display section in 
pixels of three pixel rows on a diagonal line of the display section. 
EXAMPLE 1 
FIG. 1 is a cross sectional view showing the configuration of a liquid 
crystal display device according to Example 1 of the present invention. 
The liquid crystal display device shown in FIG. 1 includes a pair of 
substrates 1a and 1b facing each other and a display medium interposed 
therebetween. The display medium includes polymer walls 7 and liquid 
crystal regions 6. The polymer walls 7 and the liquid crystal regions 6 
are formed by phase-separation. A plurality of strip-shaped transparent 
electrodes 2a for display are formed at predetermined intervals on the 
surface of the substrate 1a so as to face the display medium. A plurality 
of strip-shaped transparent electrodes 2b for display are formed at 
predetermined intervals on the surface of the substrate 1b facing the 
display medium so as to cross the electrodes 2a. Furthermore, a shielding 
layer 8 for reducing the amount of ultraviolet rays transmitted 
therethrough is formed on the ends of the substrates 1aand the transparent 
electrodes 2a. Similarly, a shielding layer 8 for reducing the amount of 
UV light transmitted therethrough is formed on the ends of the substrate 
1b and the transparent electrodes 2b. An electrically insulating film 3a 
is formed so as to cover the substrate 1a, the transparent electrodes 2a 
and the shielding layer 8. Similarly, an electrically insulating film 3b 
is formed so as to cover the substrate 1b, the transparent electrode 2b 
and the shielding layer 8. Furthermore, alignment films 4a and 4b are 
formed on the electrically insulating film 3a and 3b, respectively. A 
region interposed between the transparent electrodes 2a and 2b facing each 
other serves as a pixel section 10. The pixel section 10 is included in 
the liquid crystal region 6. Furthermore, both ends of the display medium 
are sealed with a sealing material 5 so that the pair of substrates 1a and 
1b face each other interposing a predetermined distance therebetween. 
Spacers 9 serving as substrate gap controlling materials are dispersed in 
gaps between the pair of substrates. 
The liquid crystal display device according to Example 1 is characterized 
in that the shielding layers 8 are formed on the surfaces of the 
substrates in the end portions of the substrates so as to face the display 
medium. The end portions of the substrates are referred to collectively as 
a non-display section B and correspond to a region at least between a 
display section A and the sealing material 5. In the display section A, a 
plurality of regions where the transparent electrodes 2a and 2b cross each 
other, i.e., pixels 10, are present. The non-display section B corresponds 
to a peripheral region of the display section A, and includes a region 
where the sealing material 5 for attaching the pair of substrates to each 
other is provided. 
As described above, the shielding layers 8 for reducing the amount of 
transmitted ultraviolet rays are provided in the non-display section B. As 
a result, the amount of ultraviolet rays radiated into the non-display 
section B can be reduced so as to inhibit the polymerization of a 
photopolymerizable compound in the non-display section B. Thus, a polymer 
or a photopolymerizable compound is prevented from flowing into the 
non-display section B from the display section A. 
The liquid crystal display device according to Example 1 described above 
can be fabricated, for example, as follows. 
First, ITO films are respectively formed on the substrates 1a and 1b to a 
thickness of 2000 angstroms by sputtering or the like so as to form the 
strip-shaped transparent electrodes 2a and 2b at predetermined intervals. 
Next, the shielding films 8 are formed in the peripheral regions of the 
display sections A (i.e., non-display sections B) using metal films made 
of Mo, Cr, Ni, Cu, Al or the like or inorganic films made of SiO.sub.2 or 
ITO for reducing the amount of transmitted ultraviolet rays. Furthermore, 
the electrically insulating films 3a and 3b are respectively formed 
thereon so as to cover the shielding films 8. Then, the alignment films 4a 
and 4b are formed on the electrically insulating films 3a and 3b. The 
alignment films 4a and 4b are rubbed with a nylon cloth. 
As a material of the substrates, any material can be used as long as at 
least one substrate is made of a transparent material capable of 
transmitting light. For example, a glass substrate, a plastic film or the 
like can be used. Moreover, one substrate may be opaque and may be 
provided with a metal film or the like as long as the other substrate is 
transparent. It is sufficient to form the shielding films 8 so as to cover 
at least a region between the sealing materials 5 and the display section 
A. However, the shielding films 8 may be formed so as to cover the entire 
non-display section B including the regions where the sealing materials 5 
are provided. Furthermore, the alignment films 4a and 4b are formed as 
they are needed. If the alignment films 4a and 4b are not necessary, they 
may be omitted. 
The thus formed substrates 1a and 1b are disposed so that the transparent 
electrodes 2a and 2b are orientated perpendicular to each other. The 
spacers 9 are dispersed in gaps between the substrates 1a and 1b. Then, 
both ends of the substrates are attached by the sealing material 5, 
thereby completing a liquid crystal cell. 
A mixed material containing at least a liquid crystal material, a 
photopolymerizable compound and a photopolymerization initiator 
(hereinafter, referred to as a mixed liquid crystal material) is injected 
into gaps of the thus produced liquid crystal cell. As the liquid crystal 
material, any liquid crystal material which is conventionally used for a 
liquid crystal display device operating in a TN mode, a STN mode, an ECB 
mode, a ferroelectric liquid crystal mode, a light scattering mode or the 
like can be used. For example, in the case where a liquid crystal display 
device performs a display in an STN display mode, XL1-4427 (fabricated by 
Merk & Co., Inc) to which a chiral agent (S-811) is added at 0.3% can be 
used. As the photopolymerizable compound, p-phenylstyrene, isobornyl 
methacrylate, perfluoroalkyl methacrylate, or a combination thereof can be 
used. As the photopolymerization initiator, Irugacure 651 (fabricated by 
CHIBAGAIGY CO., LTD) can be used, for example. During this procedure, an 
injection opening is sealed with a UV curable resin so that the display 
section A is not irradiated with light in the following UV irradiation 
process. 
Next, the mixed liquid crystal material is irradiated with UV light having 
a distribution of intensity over the display section A by a photomask or 
the like from the exterior of the liquid crystal cell. A high-pressure 
mercury lamp for radiating UV light, with which collimated light beams can 
be obtained, is used as a light source. The irradiation intensity of the 
high-pressure mercury lamp is, for example, 10 mW/cm.sup.2. A temperature 
of the substrate during UV ray irradiation may be set at room temperature. 
Alternatively, a temperature of the substrate during UV ray irradiation 
may be set at a temperature at which liquid crystal molecules are in an 
anisotropic liquid crystal state between the substrates. In this case, the 
orientation of liquid crystal molecules can be stabilized. By radiating UV 
light onto the mixed liquid crystal material, the polymer and the liquid 
crystal material are separated from each other in different phases. As a 
result, liquid crystal regions 6 are formed in regions irradiated with 
weak light in the display section A while polymer walls 7 are formed in 
regions irradiated with intense light in the display section A. At this 
time, the photopolymerizable compound is inhibited from being polymerized 
since UV light are shielded by the shielding layers 8 so as not irradiate 
the non-display section B. Thus, it is possible to prevent a polymer or a 
photopolymerizable compound from flowing into the non-display section B 
from the display section A. 
In the case where UV irradiation is performed at high temperature so as to 
stabilize the orientation of liquid crystal molecules, it is preferred 
that the liquid crystal cell be cooled to room temperature in a cooling 
oven. A cooling speed is preferably in the range of 3.degree. C./h to 
20.degree. C./h, and more preferably, 5.degree. C./h to 10.degree. C./h. 
The unreacted photopolymerizable compound may be cured by irradiating the 
entire substrate with weak ultraviolet rays at room temperature again 
after the mixed liquid crystal material is separately formed into the 
polymer walls and the liquid crystal regions, if necessary. At this time, 
although a PDLC type wall or a polymer wall is formed in the region other 
than the display section A (i.e., non-display section B), the polymer in 
the display section which is separated into two different phases does not 
flow into the non-display section B since it already has been cured. 
Therefore, the liquid crystal regions 6 and the polymer walls 7 of the 
display section A are not affected thereby. 
A polymer wall formation rate in the periphery of the display regions of 
the thus produced liquid crystal display device is shown in Table 1 below. 
For comparison, a conventional liquid crystal display device, in which the 
shielding layers 8 are not provided, is also shown in Table 1 as a 
Comparative Example. 
TABLE 1 
______________________________________ 
Comparative 
Example 1 
Example 
______________________________________ 
Polymer wall 98.4 50.4 
formation 
rate (%) 
______________________________________ 
As can be seen from Table 1 above, the liquid crystal display device 
according to Example 1 is capable of reducing poor formation of the 
polymer wall in the periphery of the display section A adjacent to the 
non-display section B. 
EXAMPLE 2 
A liquid crystal display device in Example 2, as represented in FIG. 2A, 
differs from that in Example 1 in that the shielding layers 8 for reducing 
the amount of UV light to be transmitted are provided on the outer surface 
of one of the substrates 1a and 1b. The liquid crystal material and the 
photopolymerizable compound are the same as those used in Example 1. The 
configuration of the liquid crystal display device is the same as that is 
Example 1 except that the shielding layers 8 are not provided onto the 
surfaces of the substrates 1a and 1b so as to face the display medium. 
The liquid crystal display device according to Example 2 can be fabricated, 
for example, as follows. 
First, a mixed liquid crystal material such as that in Example 1 is 
injected into the liquid crystal cell fabricated in the same process as 
that of Example 1 except that the shielding layers 8 are not formed. Then, 
an injection opening is sealed. 
Next, UV light having a distribution of intensity over the display section 
A by a photomask or the like is radiated into the mixed liquid crystal 
material from the outside of the liquid crystal cell. The light source and 
the irradiation intensity of the source are the same as those in Example 
1. UV ray irradiation is performed while a photomask (a shielding layer 8) 
or the like is placed on the non-display section B on the externally 
exposed side of the substrate. It is sufficient that the shielding layer 8 
is formed so as to cover at least a region between the sealing material 5 
and the display section A. However, the shielding layer 8 may be formed on 
the entire non-display section B. A substrate temperature during UV ray 
irradiation may be set at room temperature or a temperature at which 
liquid crystal molecules are in an anisotropic liquid crystal state 
between the substrates. The phase separation between the polymer and the 
liquid crystal is caused by UV ray irradiation, thereby forming the liquid 
crystal regions 6 in regions irradiated with weak light in the display 
section a and the polymer walls 7 in regions irradiated with intense light 
in the display section A. The phase separation is insufficiently caused in 
the region covered with the photo mask, resulting in a mixture containing 
at least a liquid crystal material and a photopolymerizable compound to be 
left. Since the non-display section B is prevented from being irradiated 
with UV light by the photomask, polymerization of the photopolymerizable 
compound is inhibited. Thus, the polymer or the photopolymerizable 
compound is prevented from flowing into the non-display section B from the 
display section A. 
In the case where UV irradiation is performed at high temperature so as to 
stabilize the orientation of liquid crystal molecules, it is preferred 
that the liquid crystal cell be cooled to room temperature in a cooling 
oven after UV irradiation as in Example 1. A cooling speed is preferably 
in the range of 3.degree. C./h to 20.degree. C./h, and more preferably, 
5.degree. C./h to 10.degree. C./h. After the phase separation is caused in 
this way, an unreacted photopolymerizable compound may be cured by 
radiating UV light onto the entire substrate at weak intensity at room 
temperature again, if necessary. If UV ray re-irradiation is performed, a 
PDLC wall or a polymer wall is formed in the region outside the display 
section A (i.e., the non-display section B). Since, the polymer in the 
non-display section A, which are already separated into the polymer walls 
and the liquid crystal regions, have been already cured, the polymer does 
not flow into the non-display section B. Therefore, as in Example 1, the 
liquid crystal regions 6 and the polymer walls 7 of the display section A 
are not affected. 
A polymer wall formation rate in the periphery of the display regions of 
the thus produced liquid crystal display device according to Example 2 is 
shown in Table 2 below. For comparison, a conventional liquid crystal 
display device, in which the photomask is not formed in the non-display 
section B, is also shown in Table 2 as a Comparative Example. In Table 2, 
the polymer wall formation rate represents a rate at which four contiguous 
polymer walls surrounding a pixel is successfully formed in the polymer 
walls surrounding the pixels in three columns adjacent to the non-display 
section B (the pixels from the end of the display sections A to the third 
circuit). 
TABLE 2 
______________________________________ 
Comparative 
Example 2 
Example 
______________________________________ 
Polymer wall 97.6 50.4 
formation 
rate (%) 
______________________________________ 
As can be seen from Table 2 above, the liquid crystal display device 
according to Example 2 is capable of reducing poor formation of the 
polymer wall in the periphery of the display section A adjacent to the 
non-display section B. 
EXAMPLE 3 
A liquid crystal display device in Example 3, as also represented in FIG. 
2A, differs from that in Example 1 in that the shielding layers 8 for 
reducing the amount of UV light to be transmitted are externally provided 
on the liquid cell. The liquid crystal material and the photopolymerizable 
compound are the same as those used in Example 1. The configuration of the 
liquid crystal display device is the same as that in Example 1 as shown in 
FIG. 2A except that the shielding layers 8 are not provided onto the 
surfaces of the substrates 1a and 1b facing the display medium. 
The liquid crystal display device according to Example 3 can be fabricated, 
for example, as follows. 
First, the same mixed liquid crystal material as that in Example 1 is 
injected into the liquid crystal cell fabricated in the same process as 
that of Example 1 except that the shielding layers 8 are not formed. Then, 
an injection opening is sealed. 
Next, UV light having a distribution of intensity over the display section 
A by a photomask or the like is radiated into the mixed liquid crystal 
material from the outside of the liquid crystal cell. The light source and 
the irradiation intensity of the source are the same as those in Example 
1. However, as shown in FIG. 2B, UV ray irradiation is performed while a 
mask 14 is provided for a UV ray irradiation lamp 13 so that the 
non-display section B of a liquid crystal cell 11 is not irradiated with 
UV light 12. A substrate temperature during UV ray irradiation may be set 
at room temperature or a temperature at which liquid crystal molecules are 
in an anisotropic liquid crystal state between the substrates. The phase 
separation between the polymer and the liquid crystal is caused by UV ray 
irradiation, whereby the liquid crystal regions 6 are formed in the region 
irradiated with weak light and the polymer walls 7 are formed in the 
region irradiated with intense light within the display section A. Since 
the non-display section B of the liquid crystal cell 11 is prevented from 
being irradiated with the UV light 12 by the mask 14, the polymerization 
of the photopolymerizable compound is prevented. As a result, a mixture 
containing at least a liquid crystal material and a photopolymerizable 
compound is left uncured. Thus, the polymer or the photopolymerizable 
compound is prevented from flowing into the non-display section B from the 
display section A. 
in the case where UV irradiation is performed at high temperature so as to 
stabilize the orientation of liquid crystal molecules, it is preferred 
that the liquid crystal cell is cooled to room temperature in a cooling 
oven after UV irradiation as in Example 1. A cooling speed is preferably 
in the range of 3.degree. C./h to 20.degree. C./h, and more preferably, 
5.degree. C./h to 10.degree. C./h. After the phase separation is 
performed, an unreacted photopolymerizable compound may be cured by 
radiating UV light onto the entire substrate at weak intensity at room 
temperature again, if necessary. If UV ray re-irradiation is performed, a 
PDLC wall or a polymer wall is formed in the region outside the display 
sections A (i.e., the non-display sections B). However, the polymer in the 
non-display sections A, which have been already separated into the polymer 
walls and the liquid crystal regions, are already cured, the polymer does 
not flow into the non-display sections B. Therefore, the liquid crystal 
regions 6 and the polymer walls 7 of the display sections A are not 
affected as in Example 1. 
A polymer wall formation rate in the periphery of the display regions of 
the thus produced liquid crystal display device according to Example 3 is 
shown in Table 2 below. For comparison, a conventional liquid crystal 
display device, in which the UV irradiation lamp is not provided with a 
mask, is also shown in Table 3 as a Comparative Example. 
TABLE 3 
______________________________________ 
Comparative 
Example 3 
Example 
______________________________________ 
Polymer wall 97.5 50.4 
formation 
rate (%) 
______________________________________ 
As can be seen from Table 3 above, the liquid crystal display device 
according to Example 3 is capable of reducing poor formation of the 
polymer wall in the periphery of the display section A adjacent to the 
non-display section B. 
EXAMPLE 4 
Referring to FIGS. 3A-3D, a liquid crystal material and a 
photopolymerizable compound in Example 4 are the same as those used in 
Example 1. The configuration of a liquid crystal display device according 
to Example 4 is same as that of Example 2 except that a sealing material 
21 is provided in the boundary regions between the display section A and 
the non-display section B as shown in FIGS. 3A through 3D. 
The liquid crystal display device according to Example 4 can be fabricated, 
for example, as follows. 
First, the shielding layers 8 are omitted, and the sealing material 5 is 
provided in the boundary regions between the display sections A and the 
non-display section B in the liquid crystal display device according to 
Example 4. A sealing material 22 may be provided in the non-display 
section B in the outer periphery of the boundary region, if necessary. If 
the sealing material 22 is further provided, a double seal serves to 
increase the panel strength. Therefore, pressure-resistance against a 
pushing force applied in the case of, for example, data input with a pen, 
can be increased. A liquid crystal material may be injected into gaps 
between the sealing materials 21 and 22 so that the gap regions serve as 
display regions. If a substrate having a seal pattern as shown in FIG. 3B 
is used, it becomes possible to inject a liquid crystal material which 
does not contain the photopolymerizable compound into the double seals, 
for example. Moreover, it is possible to inject different liquid crystal 
materials into the display sections and the region between double seals. 
If a width of the sealing material 21 serving as a inner seal is set in 
the range of 50 .mu.m to 2 mm, the sealing material will obtain such 
strength that the panel is not destroyed by vacuum injection. Thus, it is 
possible to render the sealing material 21 serving as the inner seal less 
conspicuous in a display. The liquid crystal cell is produced in the same 
process as that of Example 1 except the above conditions. The same mixed 
liquid crystal material as that in Example 1 is injected into the liquid 
crystal cell, and then, the injection opening thereof is sealed. 
Next, UV light having a distribution of intensity over the display section 
A by a photomask or the like is radiated into the mixed liquid crystal 
material from the outside of the liquid crystal cell. The light source and 
the irradiation position are the same as those in Example 1. A substrate 
temperature during UV ray irradiation may be set at room temperature or a 
temperature at which liquid crystal molecules are in an anisotropic liquid 
crystal state between the substrates. The phase separation between the 
polymer and the liquid crystal is caused by UV ray irradiation, thereby 
forming the liquid crystal regions 6 in the region irradiated with weak 
light and the polymer walls 7 in the region irradiated with intense light 
within the display section A. In this phase separation process, since the 
inner seal 21 is formed in the boundary region between the display section 
A and the non-display section B, the polymer or the photopolymerizable 
compound is prevented from flowing into the non-display section B from the 
display section A. 
In the case where UV irradiation is performed at high temperature so as to 
stabilize the orientation of liquid crystal molecules, it is preferred 
that the liquid crystal cell be cooled to room temperature in a cooling 
oven after UV irradiation as in Example 1. A cooling speed is preferably 
in the range of 3.degree. C./h to 20.degree. C./h, more preferably, 
5.degree. C./h to 10.degree. C./h. After the phase separation is performed 
in this way, an unreacted photopolymerizable compound may be cured by 
radiating UV light onto the entire substrate at weak intensity at room 
temperature again, as needed. 
A polymer wall formation rate in the periphery of the display regions of 
the thus produced liquid crystal display device according to Example 4 is 
shown in Table 4 below. For comparison, a conventional liquid crystal 
display device, in which the inner seal is not formed, is also shown in 
Table 4 as a Comparative Example. 
TABLE 4 
______________________________________ 
Comparative 
Example 4 
Example 
______________________________________ 
Polymer wall 98.8 50.4 
formation 
rate (%) 
______________________________________ 
As can be seen from Table 4 above, the liquid crystal display device 
according to Example 4 is capable of reducing poor formation of the 
polymer wall in the periphery of the display section A adjacent to the 
non-display section B. 
EXAMPLE 5 
In Example 5, a liquid crystal material and a photopolymerizable compound 
are the same as those used in Example 1. The configuration of a liquid 
crystal display device according to Example 5, as represented in FIG. 4, 
is the same as that in Example 2 except that electrodes having the same 
shape as those formed in the display section A are further formed in the 
non-display section B. 
The liquid crystal display device according to Example 5 can be fabricated, 
for example, as follows. 
First, a liquid crystal cell is fabricated by the same procedure as that of 
Example 1 except that the shielding layers 8 are not provided and 
electrodes having the same configuration as those of the display section A 
are further formed in the non-display section B. A mixed liquid crystal 
material is injected into the liquid crystal cell, and then an injection 
opening is sealed. 
Next, UV light having a distribution of intensity over the display section 
A are radiated into the mixed liquid crystal material from the outside of 
the liquid crystal cell. The light source and the irradiation intensity of 
the source are the same as those in Example 1. A substrate temperature 
during UV ray irradiation may be set at room temperature or a temperature 
at which liquid crystal molecules are in an anisotropic liquid crystal 
state between the substrates as in Example 1. The phase separation between 
the polymer and the liquid crystal is caused by UV ray irradiation, 
thereby forming the liquid crystal regions 6 in the region irradiated with 
weak light and the polymer walls 7 irradiated with intense light within 
the display section A. 
In the case where UV irradiation is performed at high temperature so as to 
stabilize the orientation of liquid crystal molecules, it is preferred 
that the liquid crystal cell be cooled to room temperature in a cooling 
oven after UV irradiation as in Example 1. A cooling speed is preferably 
in the range of 3.degree. C./h to 20.degree. C./h, more preferably, 
5.degree. C./h to 10.degree. C./h. After the phase separation is 
performed, an unreacted photopolymerizable compound may be cured by 
radiating UV light onto the entire substrate at weak intensity at room 
temperature again, as needed. 
A polymer wall formation rate of the thus produced liquid crystal display 
device according to Example 5 for each column and each row is shown in 
Table 5 below. In Table 5, although only one-fourth of the liquid crystal 
cell is measured in this case, it is considered that the results can be 
applied to the remaining three-fourths. 
TABLE 5 
______________________________________ 
Polymer wall formation rate (%) 
Column 
first Fourth 11th 
to to to 
third tenth 320th 
______________________________________ 
Row first 30.2 50.7 65.8 
to 
third 
fourth 50.4 97.6 98.2 
to 
tenth 
11th 67.2 97.8 98.8 
to 
120th 
______________________________________ 
As can be seen from Table 5 above, the polymer wall formation rate is low 
in pixels in 3 columns.times.3 rows (pixels from the outermost row and 
column to the pixel of the third column and third row). Therefore, if the 
pixels in at least 3 columns.times.3 rows are formed in the non-display 
section so as to be adjacent to the display section, poor formation of the 
polymer wall can be reduced over the entire display section A. 
In Examples 1 through 5 described above, the liquid crystal display device 
which performs a display in a simple matrix driving method is described. 
However, the above-mentioned results can be applied to the liquid crystal 
display device which performs display in an active driving method using 
thin film transistors (TFTs) or metal insulator metal (MIM), and a driving 
method is not particularly limited. By changing the kind of the liquid 
crystal material injected into the liquid crystal cell and the kind of the 
alignment film, a liquid crystal display device which can be driven in a 
TN mode, a STN mode, a FLC mode or an ECB mode can be produced. Moreover, 
a liquid crystal display device utilizing a light scattering mode can be 
produced. Furthermore, by providing polarizers or reflectors on both 
surfaces of the liquid crystal cell, a transmission type or a reflection 
type liquid crystal display device can be produced. In addition, by 
forming a color filter or a black matrix, color display can also be 
performed. 
As described above, according to the present invention, polymerization of a 
photopolymerizable compound is inhibited in the boundary region between 
the display section and the non-display section. Thus, since a stable 
polymerization reaction can be caused in the display section, the amount 
of polymer flowing from the display section to the non-display section, 
which conventionally occurs, can be reduced. As a result, it is ensured 
that polymer walls are formed at desired postions. 
By providing a sealing material in the boundary region between the display 
section and the non-display section, the effect of preventing the polymer 
from flowing into the non-display section from the display section is 
obtained. In addition, the display medium (a liquid crystal material and a 
polymer) is present only in the display section. Thus, the amount of 
liquid crystal material and polymer to be used can be reduced. 
Furthermore, by providing a double seal, resistance of the device against 
external pushing force can be enhanced so as to improve the reliability of 
the panel. In addition, by injecting a liquid crystal material between a 
gap between the double seals, the region can be used for display. 
Therefore, the substrates can be effectively used. 
Furthermore, by making an irradiated area of the non-display section 
adjacent to the display section equal to that of the display section, a 
polymer wall formation rate in the display section can be increased. 
during use of such device, sufficient resistance against an external 
pushing force such as an input with a pen can be uniformly reserved in the 
entire panel. 
As described above, a polymer wall formation rate in the display section 
can be increased. The poor formation of polymer walls, which 
conventionally occurs more in the periphery of the display section than in 
the central region due to difference in refractive index of light between 
the liquid crystal molecules and the polymer, can be reduced. As a result, 
display with reduced unevenness of color can be performed. At the same 
time, a required amount of liquid crystal material and polymer material 
can be reduced, and the substrates are effectively used. Thus, an 
industrially and commercially effective liquid crystal display device can 
be produced. 
Various other modifications will be apparent to and can be readily made by 
those skilled in the art without departing from the scope and spirit of 
this invention. Accordingly, it is not intended that the scope of the 
claims appended hereto be limited to the description as set forth herein, 
but rather that the claims be broadly construed.