Process for manufacturing a multi-colored display polarizer

A multi-colored display polarizer is manufactured by supporting on a transparent substrate a multi-colored polarizing film which is produced by a required number of repetitions, each using a coloring means producing a different color, a sequence of operations comprising coating a photosensitive resin onto the surface of a polarizing film blank and drying the same, exposing the coated film through a photographic negative having a desired pattern thereon to photo-set a portion of the film corresponding to the transparent portion of the negative, developing the thus exposed film, coloring the thus developed film with a suitable coloring means, and removing the photosensitive resin remaining on said photoset portion of the film.

BACKGROUND OF THE INVENTION 
The present invention relates to a process for manufacturing a 
multi-colored display polarizer which is suitably applicable, for example, 
to a liquid crystal display unit. 
In general, to manufacture a polarizer, a blank of polymeric material such 
as polyvinyl alcohol, cellophane or the like on which iodine, dyestuff and 
so on is adsorbed is first oriented in one direction to form a polarizing 
film and, then, a transparent substrate of cellulosic resin, acrylic 
resin, film, glass or the like material is applied onto one or both sides 
of the resultant polarizing film so that the polarizing film can retain a 
stable polarizability. 
A wide variety of liquid crystal display units have been proposed so far, 
in which a polarizer formed in the aforementioned manner is positioned on 
the topside and underside of an electrode cell hermetically filled with a 
liquid crystal in such a manner that the axes of polarization of two 
polarizers are normal to each other for permitting desired patterns such 
as alphamerics to be displayed depending upon an application of voltage to 
the electrode cell. 
However, in such prior art polarizers, since the polarizer itself has 
optically uniform and homogeneous characteristics over its entirety, the 
display comprises a monochromatic pattern based on a difference in 
brightness only, except for those cases in which one of the polarizers has 
different optical characteristics by being treated with a coloring or 
other processing. Therefore, even if such a prior art polarizers are used 
in display panels of measuring instruments such as flow meters, level 
meters and so on, the display obtained thereby is monotonous without a 
change in color and may often be erroneously read or overlooked. Further, 
the prior art polarizers are also unsatisfactory in that only a limited 
variation is allowed in designing and, therefore, are not suited for 
educational toys that particularly require colorful changes. 
To overcome such shortcomings of the conventional polarizers, an 
application of polarizing films consisting of narrow film strips with 
different colors onto the aforesaid transparent substrate in an optical 
manner or a transfer of printing of a polarizing ink consisting of iodine, 
dyestuff and so forth onto the aforesaid blank of polymeric material such 
as polyvinyl alcohol has been proposed. However, in the first method cited 
immediately above, it is not only difficult to apply the polarizing films 
to the transparent substrate without leaving a gap between any two 
adjacent polarizing films, but also to obtain polarizers of a stable 
quality because the polarizing films tend to exfoliated from the 
transparent substrate as time elapses. While, in the latter method cited 
above, it is also difficult to ensure a sharp separation of color zones, 
because two adjacent colored polarizing strips overlap with each other or 
are spaced apart by a small gap from each other at the boundary thereof 
due to blotting of the polarizing ink or depending upon the skills of 
transfer technique used. 
The present invention has been achieved to overcome the aforementioned 
shortcomings of the polarizers according to the prior art. 
SUMMARY OF THE INVENTION 
An object of the present invention is to provide a process for 
manufacturing in a simplified manner a multi-colored display polarizer 
which has a sharp colar separation without overlaps or gaps at the 
boundaries of any two adjacent colored polarizing strips thereof each 
having a different color. 
Another object of the present invention is to provide a process for 
manufacturing a multi-colored display polarizer which can maintain a 
stable polarizability over a substantial period of time without a 
possibility of successively disposed colored polarizing strips with 
different colors being oxfoliated from the transparent substrate thereof 
due to aging. 
A further object of the present invention is to provide such a process for 
manufacturing a multi-colored display polarizer that can form desired 
patterns such as letters, figures, symbols and so forth on one single 
transparent substrate in desired colors. 
That is to say, the present invention provides, in the manufacture of a 
polarizer composed of a polarizing film and a transparent substrate for 
supporting the same, a process for manufacturing a multi-colored display 
polarizer, comprising coating a photosensitive resin onto the surface of a 
polarizing film bank and drying the same, exposing the thus coated film 
through a photographic negative to photo-set the photosensitive resin at 
that portion of said coated film corresponding to the transparent portion 
of said photographic negative, developing the thus exposed film by 
dissolving and removing the resin remaining on the unexposed portion of 
said coated film to disclose the original transparent polarizing film 
blank thereunder, coloring only the thus disclosed transparent polarizing 
film blank portion with a polarizing ink composed of iodine, dyestuff and 
so forth to form a colored polarizing film, followed by a removal of the 
resin on said photo-set portion of said coated film, and repeating, each 
time by using a polarizing ink producing a different color, the foregoing 
sequence of operations for a required number of times for forming on said 
polarizing film blank a desired multi-colored pattern such as a striped 
pattern, figure, symbol or the like. 
The photosensitive resin (hereinafter referred to as photo-resist) 
applicable to the process according to the present invention has a liquid 
state under normal conditions and includes water-soluble resins such as 
dichromate type photo-resists obtained by blending a dichromate with 
isinglass, casein, polyvinyl alcohol (PVA), etc., acrylic photo-resists 
obtained by copolymerizing a vinyl monomer with methyl methacrylate, etc. 
and so forth; and oil-soluble resins such as polyvinyl cinnamate type 
photo resists obtained by blending a polyvinyl cinnamate with various 
photosensitizers, cyclized rubber-azide type photo-resists obtained by 
blending a cyclized natural or synthetic rubber with an aromatic bisazide 
compound such as 2,6-di-(4'-azidebenzal)-cyclohexanone, etc. and so forth. 
The foregoing are so-called negative type photo-resists. Besides these, an 
oil-soluble o-naphthoquinone diazide type photo-resist which produces a 
water-soluble cyclopentacarboxylic acid by being irradiated by light may 
be used. 
Any of the aforementioned photo-resists is coated onto a polarizing film 
blank and the thus coated film is dried to form thereon a photosensitive 
layer of about 10.about.50.mu. thick. Then a photographic negative having 
a desired pattern is placed thereon and the photosensitive layer of the 
film covered with said negative is irradiated by light. In this manner, a 
photo-set portion and a non-set portion are produced on the photosensitive 
layer correspongingly to said pattern of the photographic negative. 
Thereafter, the aforesaid non-set portion of the photo-sensitive layer is 
washed off therefrom with water or a suitable organic solvent to disclose 
the original polarizing film blank, while said photo-set portion is left 
on the film as an insolubilized gelcoat. That is so say, said irradiated 
film is developed. In this case, a suitable developer is selected 
depending on the particular photo-resist used. For example, water is 
suitable for dichromate type photo-resists, xylene or trichloroethylene or 
the like for polyvinyl cinnamate type photo-resists, and aromatic 
hydrocarbons such as toluene, xylene, etc. for cyclized rubber-azide type 
photo-resists, respectively. 
That portion of the polarizing film blank dissolved by the development is 
colored in a desired color by being immersed in a polarizing ink 
(solution) composed of iodine, dyestuff and other components. 
The dyestuff for said coloring processing may be any well-known dyestuff, 
such as acid dye and direct dye, having a sufficient coloring power to the 
film blank such as polyvinyl alcohol (PVA) but without an affinity for 
said photo-set portion of the photosensitive layer of the film. For 
example, those dyestuffs listed immediately below can be advantageously 
used for executing the present invention: 
______________________________________ 
Trade name Color code index 
______________________________________ 
Acid Dye; 
Naphthol Yellow-S 10316 
Kayaku Acid Light Yellow 2G 
18965 
Suminol Fast Red B 14680 
Solar Red RB 14895 
Suminol Black 8BX 26370 
Sumilan Black WA 15711 
Aizen Violet 3RH 16055 
Solar Pure Blue VX 42051 
Suminol Blue BL 50315 
Sumitomo Light Green SF Yellowish 
42095 
Direct Dye; 
Kayaku Direct Brilliant Yellow G 
24890 
Kayarus Yellow GC 29000 
Kayaku Congo Red 22120 
Aizen Direct Violet LNH 
22480 
Kayaku Direct Copper Blue 2B 
24185 
Kayarus Cupro Green G 34040 
Kayaku Direct Fast Black D 
27700 
______________________________________ 
On the polarizing film blank which is partially colored with the polarizing 
ink as mentioned above, there also remains some of the said photo-set 
portion as an insolubilized gelcoat. This photo-set portion of the 
photosensitive resin is washed off with a suitable solvent to disclose the 
original polarizing film blank thereunder. Thus, a polarizing film which 
is partially colored at that portion thereof corresponding to the 
transparent portion of the photographic negative is produced. 
The solvent used for washing off the aforesaid photo-set portion of the 
photosensitive resin must be of such a type that does not affect said 
colored portion of the polarizing film in any manner and, for example, a 
dilute aqueous alkali solution may be used for the aforementioned acrylic 
photo-resists, monochlorobenzene for polyvinyl cinnamate type 
photo-resists, and trichloroethylene or perchloroethylene for cyclized 
rubber-azide type photo-resists, respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
Referring now to the drawings, especially, to FIG. 1 showing a film blank 
used for manufacturing the multi-colored display polarizer according to 
the present invention, the reference numeral 1 indicates the polarizing 
film blank which is obtained by orienting a polymeric material such as 
polyvinyl alcohol (PVA) in one direction and fixating by drying the thus 
oriented material (FIG. 1A). 3 is a laminate obtained by optically 
applying and fixing the aforesaid polarizing film blank 1 onto a 
transparent substrate 2 of a cellulosic resin, acrylic resin or the like 
material. The transparent substrate 2 may be pre-colored. 
Referring now to FIG. 2 illustrating in sequence the various steps of the 
process for manufacturing the multi-colored display polarizer according to 
the present invention, a photo-resist liquid is first coated onto the 
surface of said polarizing film blank 1 of the laminate 3 and dried to 
form thereon a photosensitive layer 4 of colloidal cost (FIG. 2A). 
Then, a photographic negative 5 is placed on said photosensitive layer 4 in 
close contact therewith and exposed to the light L. On said photographic 
negative 5, transparent portion 5a of strip shape and opaque portions of 
5b of the like strip shape, namely, white and black stripes are 
alternately disposed so as to form a grating pattern. For the exposure to 
light L, a light emitted by a high-pressure mercury vapor lamp, carbon arc 
lamp, xenon lamp or the like source is used for 30 seconds to 3 minutes to 
irradiate said photosensitive layer 4. 
As a result of said exposure, the photosensitive layer 4 has its portions 
corresponding to the transparent portions 5a of the photographic negative 
5 only photo-set, so that set portions 4a and non-set portions 4b are 
formed in said photosensitive layer 4 (FIG. 2B). 
Thereafter, the thus laminate 3 having said photosensitive layer 4 is 
developed by dissolving and removing said non-set portions 4b of the 
photosensitive layer 4 with water or a suitable organic solvent to 
disclose the original polarizing film blank 1. Thus, a positive plate 6 on 
which said photo-set portions 4a are left as an insolubilized gelcoat is 
obtained (FIG. 2C). 
Thereafter, said positive plate 6 is immersed in a polarizing ink 
(solution) composed of iodine, dyestuff and so on which colors only said 
disclosed polarizing film blank 1 without coloring said photo-set portion 
4a of the photosensitive layer 4. Thus, a polarizer 8 can be produced, in 
which colored polarizing film portions 7a are formed so as to present as a 
whole a monochromatic grating pattern corresponding to the opaque portions 
5b of the photographic negative 5 (FIG. 2D). 
Then, the resin at said set portion 4a of the polarizer 8 is removed to 
disclose the original transparent polarizing film blank 1 thereunder by 
using a suitable solvent which does not act to release the colored 
polarizing films 7 from the polymerizing film blank 1, and the 
photo-resist liquid is coated again on the entire surface of the topside 
of the polarizer 8 and dried to form another photosensitive layer 9. 
Subsequently thereto, another photographic negative 10 having transparent 
portions 10a and opaque portions 10b which are disposed exactly oppositely 
to the transparent portions 5a and opaque portions 5b, respectively, of 
the first-cited photographic negative 5, is placed on said photosensitive 
layer 9 in close contact therewith, and exposition and development steps 
are repeated in the same manner as described previously. 
As a result of these steps, only those portions of the photosensitive layer 
9 corresponding to the transparent portions 10a of the photographic 
negative 10 are photo-set to produce set portions remaining as an 
insolubilized gelcoat which protects the colored polarizing film portions 
7 previously formed thereunder. Those portions of the photosensitive layer 
9 facing the opaque portions 10b of said photographic negative 10 are 
dissolved and removed to disclose the polarizing film blank 1 thereunder 
(FIG. 2E). 
Thus, if the laminate 3 having the thus processed photosensitive layer 9 is 
colored by being immersed in a polarizing ink producing a color different 
from the color used previously and set portion of the photosensitive layer 
9 is washed off with a suitable solvent, a polarizer 11 on which the 
polarizing film portions 7 and 7a having a different color from each other 
are alternatively disposed so as to form a two-color grating pattern can 
be obtained (FIG. 2F). 
The foregoing description has handled a case in which a polarizer having 
two-color grating pattern is produced by using two photographic negatives 
5 and 10 each having transparent and opaque portions which are disposed 
exactly opposite, respectively, to each other. In a similar manner, a 
multi-colored display polarizer having a desired pattern can be produced 
by selecting an appropriate number of photographic negatives on which 
letters, symbols, figures or the like patterns are formed and repeated, 
each time by using a different one of the thus selected photographic 
negatives, in the aforementioned sequence of operations. 
Referring now to FIG. 3 illustrating another preferred embodiment of the 
process according to the present invention, the reference numeral 12 
indicates a polarizer composed of a transparent substrate 13 on which 
polarizing film portions 14 with letter patterns such as S, M, . . . , Sa 
representing days of the week are formed in green color as shown at the 
upper part of FIG. 3A and a polarizing film 15 of gray color as shown at 
the lower part of FIG. 3A. 
Such a polarizer 12 can be produced by using a first photographic negative 
16 having opaque portions 17 representing letters such as S, M, . . . , 
etc. at positions as shown in the upper part of FIG. 3B and a second 
photographic negative 18 having a transparent portion at the upper half 
part thereof and an opaque portion 19 at the lower half part thereof as 
shown in FIG. 3C. 
Further, as shown in FIG. 4, a polarizer which presents a monochromatic 
display of desired patterns can be obtained by using one single 
photographic negative 20 having an upper transparent portion 21 in which 
opaque portions 22 representing letters such as S, M, . . . , etc. or 
other patterns are formed and a lower opaque portion 23. 
In the process according to the present invention as described 
hereinbefore, since the respective parts of the polarizing film blank 1 to 
be colored are definitely demarcated from each other by the use of the 
photosensitive layers 4 and 9 and the photographic negatives 5 and 10, a 
multi-colored display polarizer in which the polarizing film portions 7 
and 7a colored in different colors are neither overlapped with each other 
nor spaced apart by a small gap from each other and, therefore, a definite 
color separation is ensured. 
Also, according to the present invention, unlike the prior art polarizers 
in which separately prepared polarizing films or polarizer sections are 
applied onto a transparent substrate, since the colored polarizing film 
portions 7 and 7a are formed substantially integrally with the polarizing 
film bank 1, there is no possibility of said polarizing film portions 7 
and 7a being exfoliated from the transparent substrate 2 and, thus, a 
stable polarizability can be maintained over a long period. 
Further, according to the present invention, unlike the conventional 
polarizers in which polarizing film strips are stuck onto a transparent 
substrate or polarizing ink is transferred to a film blank of polymeric 
material, a multi-colored display polarizer having a pattern in which 
complicated figures and/or colors are combined can be easily produced, 
because any plurality of photosensitive layers and photographic negatives 
such as indicated at 4, 9 and 5, 10, respectively, in FIG. 2 can be used 
in a desired combination to form polarizing film portions colored in a 
different color from each other. 
Apart from such multi-colored display polarizers, a monochromatic display 
polarizer having desired patterns such as letters, figures, symbols or the 
like corresponding to the photographic negative can be easily obtained as 
well by the process according to the present invention. 
Hereinafter, the present invention will be described by way of specific 
examples of the preferred embodiments thereof. 
EXAMPLE 1 
In the manner as shown in FIG. 1B, onto the surface of a transparent 
substrate of triacetate film of 250.mu..about.350.mu. thick, a transparent 
polarizing film blank 18.mu..about.25.mu. obtained by orienting a 
polyvinyl alcohol film at a draw ratio of 2.5.about.3.5 was optically 
applied, and the resultant laminate was cut into the size of 350.times.400 
mm, and 5 g of photo-resist (E.P.P.R produced by Tokyo Ohka Co., Ltd.) was 
evenly coated onto the surface of the polarizing film blank 1 and dried to 
obtain a coating of 15.mu..about.30.mu. thick thereon. Then, a 
black-and-white photographic negative having a striped pattern was placed 
on the surface of said photosensitive coating in close contact therewith, 
and the thus treated laminate covered with said photographic negative was 
held between a pair of glass plates and exposed for 20.about.30 seconds 
to a light emitted from a 3 KW high-pressure mercury vapor lamp placed at 
a fixed distance of about 30 cm apart therefrom. Then the thus exposed 
laminate was developed for 30.about.40 seconds in trichloroethylene vapor 
to disclose the original transparent polarizing film blank under the 
unexposed portion of the photosensitive coating, thus leaving the 
photosensitive coating at the exposed portions thereof. The thus developed 
laminate was immersed for 2.about.4 minutes in a dyestuff solution (at 
25.about.30.degree. C.) which was prepared beforehand by dissolving 1.6 g 
of Kayarus Red 4B (produced by Nippon Kayaku Co., Ltd.) and 1 g of Direct 
Brilliant Yellow G in 1 l of water, followed by rinsing and drying. 
Consequently, the aforesaid disclosed portions of the transparent 
polarizing film blank were colored in red. These red-colored portions 
appeared in a neutral reddish tinge when viewed through a polarizer of 
neutral color placed at a parallel position to said polarizing film blank, 
but appeared as a color band of thick reddish tinge when said polarizer 
was turned 90.degree. to a position normal to said polarizing film blank. 
Then, the photo-set coating at the exposed portions of the photosensitive 
coating was cleaned off by using a thinner (predominantly composed of 
xylene) and the photo-resist (aforesaid E.P.P.R) was again coated on said 
laminate, followed by drying. Thereafter, another black-and-white 
photographic negative having a complementary disposition of grating 
pattern to the first-cited photographic negative was placed thereon in 
close contact therewith, and the thus treated laminate covered with 
another photographic negative was held between a pair of glass plates and 
also exposed to a light emitted from a high-pressure mercury vapor lamp 
positioned as before, followed by a developing step in a trichloroethylene 
vapor. Consequently, the exposed photo-resist coating on said red-colored 
polarizing film portions was left on the laminate and the transparent 
polarizing film blank was disclosed at the unexposed portions of the 
photo-sensitive coating. Then, the thus developed laminate was immersed 
for 2.about.3 minutes in a dyestuff solution (at 25.about.30.degree. C.) 
which was also prepared beforehand by dissolving 2 g of Direct Copper Blue 
2B (produced by Nippon Kayaku Co., Ltd.) in 1 l of water, followed by 
rinsing and drying. Consequently, said disclosed portions of the 
transparent polarizing film blank were colored in blue, but the exposed 
portions were not colored and also cleaned off with a thinner. Thus, a 
polarizer having a two-colored grating pattern in which the red-colored 
and blue-colored bands are alternately disposed was obtained. Said 
two-colored pattern appeared as neutral reddish and bluish tinges when 
viewed through a polarizer of neutral color placed at the aforesaid 
parallel position and appeared as polarized color bands of thick red and 
blue when said polarizer was turned 90.degree. to a position normal to 
said parallel position. 
EXAMPLE 2 
After evenly coating 5 g of photo-resist (said E.P.P.R) onto a polarizing 
film blank of a transparent laminate and drying the same in the same 
manner as the aforementioned Example 1, a photographic negative having 
thereon a black letter pattern was placed thereon in close contact 
therewith. Then, said laminate and photographic negative were held between 
a pair of glass plates and irradiated for 20.about.30 seconds by a light 
emitted from a high-pressure mercury vapor lamp, and the thus exposed 
laminate was developed under vibration for 20.about.30 seconds in ligroin 
(produced by Nippon Seiyu Co., Ltd.). Consequently, the photo-resist 
coating at the exposed portions was left on the laminate, but the 
transparent polarizing film blank was disposed at the unexposed portions 
of the photo-resist coating corresponding to the letter patterns of the 
photographic negative. After being rinsed and dried, the thus developed 
laminate was immersed for 2.about.4 minutes in a dyestuff solution which 
was prepared beforehand by dissolving 2 g of Kayarus Cupro Green (produced 
by Nippon Kayaku Co., Ltd.) in 1 l of water. Consequently, said disclosed 
portions corresponding to the letter patterns of the photographic negative 
were colored, and these colored portions appeared in a neutral greenish 
tinge when viewed through a polarizer of neutral color placed at the 
parallel position, while they appeared as letters having a polarized color 
of thick green when viewed at a position normal thereto. Thereafter, the 
photo-resist coating at the exposed portions were cleaned off by using 
chlorobenzene and the photo-resist liquid was again coated thereon, 
followed by drying. Then, another photographic negative having thereon 
transparent letter patterns on a black background in contrast to the 
first-cited photographic negative was placed on the photo-resist coating 
of the laminate, and the thus treated laminate was held between a pair of 
glass plates and irradiated by a light emitted from a high-pressure 
mercury vapor lamp in the manner as described previously. Thereafter, the 
thus exposed laminate was developed in ligroin, followed by rinsing and 
drying. Consequently, the exposed portions of the photo-resist coating 
corresponding to the letter patterns of the photographic negative were 
left, while the transparent polarizing film blank was disclosed at the 
remaining unexposed portions. Then, the thus developed laminate was 
immersed for 3.about.5 minutes in a dyestuff solution (at 
25.about.30.degree. C.) which was prepared beforehand by completely 
dissolving 2 g of Direct Fast Black D (produced by Nippon Kayaku Co., 
Ltd.) in 1 l of water, followed by rinsing and drying. As a result, only 
said disclosed polarizing film blank portions were colored. Thereafter, 
the photo-resist coating at the letter pattern portions was cleaned off by 
using chlorobenzene. Thus there was produced a two-colored polarizer 
having polarizable letter patterns which appear in a neutral color when 
viewed through a polarizer of neutral color placed at the parallel 
position and which show a polarizability to gray and, at the same time, a 
polarizability to green for letter portions only at a position normal to 
said parallel position. 
EXAMPLE 3 
After evenly coating a photo-resist (T.P.R produced by Tokyo Ohka Co., 
Ltd.) onto a polarizing film blank of a transparent laminate and drying 
the same in the same manner as Example 1, a photographic negative having 
opaque patterns of letters and a symbol X was placed thereon in close 
contact therewith, and the thus treated laminate was held between a pair 
of glass and exposed therethrough. Then, the thus exposed laminate was 
developed in Trichlene vapor, followed by rinsing. Then, the thus 
developed laminate was immersed for 1.about.2 minutes in a dyestuff 
solution which was prepared beforehand by dissolving 2 g of Kayarus Black 
ARX (produced by Nippon Kayaku Co., Ltd.) in 500 ml of water and 500 ml of 
ethyl alcohol, followed by rising and drying. Consequently, the portions 
of the polarizing film blank corresponding to the patterns of letters and 
symbol X of the photographic negative were colored in gray. After rinsing 
and drying, the photo-resist coating at the exposed portions was cleaned 
off by using benzyl alcohol to disclose the polarizing film blank. The 
resultant polarizer appeared in a neutral color when viewed through a 
polarizer of neutral color placed at its parallel position, while it 
showed polarized patterns of the letters and symbol X in a polarized 
blue-purple color when said polarizer of neutral color was turned 
90.degree. to said parallel position. 
It is to be noted that, in the process according to the present invention, 
letters and color bands may be displayed in varied colors or only letter 
patterns may be partially polarized through a transparent member by using 
various combinations of photographic negatives and/or polarizing inks in 
the similar manner to those described hereinbefore. Alternatively, by 
repetitively forming a polarizable band of each color on one laminate, 
color bands of the same color equally spaced apart from one to another may 
be simultaneously produced on one polarizer, for example, such as one 
having a multi-colored equally-spaced striped pattern. 
Also, by applying an additional substrate (triacetate, acetate butyrate 
cellulose, acrylic sheet, etc.) onto the polarizing film blank, a 
polarizer having an improved durability can be obtained. Further, by 
repeating several times the aforementioned sequence of operations by using 
a suitably different color and/or pattern each time in accordance with an 
intended design and die-cutting the resultant polarizer sheet to a 
predetermined size, a polarizer which can be used for a colorful display 
unit as being disposed on the front or rear side of the liquid crystal 
cell can be manufactured.