JPH0777687A - Liquid crystal display device and its manufacture - Google Patents

Abstract

PURPOSE:To easily manufacture the color liquid crystal display device at low cost. CONSTITUTION:A color filter 30 and a black mask 31 are stuck on the reverse surface of a lower film substrate 22 which is about 0.1-0.2mm thick. The color filter 30 and black mask 31 are formed by patterning a red resin layer formed on a base film 32 by photolithography, patterning a green resin layer formed thereupon, patterning a blue resin layer formed further thereupon, and then patterning a black resin layer formed thereupon. In this case, a transparent electrode 25 can be formed directly on the top surface of the lower film substrate 22 and the resin layers of the respective colors are only patterned and formed, so that the device can easily be manufactured at low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device.

[0002]

2. Description of the Related Art FIG. 5 shows a part of an example of a conventional liquid crystal display device. This liquid crystal display device includes an upper glass substrate 1 and a lower glass substrate 2. A plurality of transparent electrodes 3 are provided on the lower surface of the upper glass substrate 1 so as to extend in the X direction, and an alignment film 4 is provided on the lower surface thereof. A black mask 5 and a color filter 6 are provided on the upper surface of the lower glass substrate 2. The black mask 5 is formed of a film made of Cr or the like and having a film thickness of about 500 to 1000 Å in a stripe shape or a lattice shape. The color filter 6 is a stripe-shaped or mosaic-shaped film formed of protein such as gelatin and having a film thickness of about 0.9 to 1.0 μm, which is provided in a portion where the black mask 5 is not formed. And every 3 pieces are dyed. A protective film 7 made of polyimide or the like is provided on the upper surface of the lower glass substrate 2 including the black mask 5 and the color filter 6. A plurality of transparent electrodes 8 extending in the Y direction are provided on the upper surface of the protective film 7, and an alignment film 9 is provided on the upper surface thereof.
Is provided. Then, the upper glass substrate 1 and the like and the lower glass substrate 2 and the like are attached to each other via a sealing material 10, and a liquid crystal 11 is sealed between them. Polarizing plates 12 and 13 are attached to the upper surface of the upper glass substrate 1 and the lower surface of the lower glass substrate 2, respectively.

By the way, as the upper and lower glass substrates 1 and 2, those having a thickness of about 0.5 to 1.5 mm are generally used. When the lower glass substrate 2 has such a relatively large thickness, parallax occurs when the color filter 6 is provided on the lower surface (outer surface) of the lower glass substrate 2, which is not preferable in the case of a liquid crystal television or the like, and as described above. Is provided on the upper surface (inner surface) of the lower glass substrate 2. Therefore, the transparent electrode 8 is provided on the color filter 6, but if it is provided directly, first, the adhesion between the material of the color filter 6 and the ITO that is the material of the transparent electrode 8 is poor, and the second is. When the transparent electrode 8 is formed, the color filter 6 is damaged, and the transparent electrode 8 is formed in the third stepped portion, which is not preferable. Therefore, as described above, the lower glass substrate 2 including the color filter 6 and the like
A protective film 7 made of polyimide or the like is formed on the upper surface of the transparent electrode 8 and a transparent electrode 8 is formed on the upper surface of the protective film 7.

[0004]

However, in such a conventional liquid crystal display device, particularly when the color filter 6 is formed, a protein-based winding such as gelatin is applied to the entire surface to form a colorless layer. Stain the colorless layer red,
The layer dyed in red is formed into a stripe shape or a mosaic shape by photolithography, then a colorless layer is formed again on the entire surface, the colorless layer is dyed in green and then formed into a stripe shape or a mosaic shape, and then a colorless layer is formed again on the entire surface. Since the colorless layer is formed and dyed blue and then formed into a stripe shape or a mosaic shape, there are problems that the number of steps is large and the cost is high. Further, although the protective film 7 is formed on the stepped portion, it is difficult to flatten the surface of the protective film 7, and especially in the case of an STN (super twisted nematic) type liquid crystal display device, the protective film 7 is protected. It is said that the level difference on the surface of the film 7 needs to be ± 0.2 μm or less, and thus there is a problem that a planarization process with extremely high difficulty is required. An object of the present invention is to provide a liquid crystal display device which can be easily manufactured at low cost and a manufacturing method thereof.

[0005]

According to a first aspect of the present invention, a liquid crystal display device is provided with a color filter on the outer surface of either one of two transparent substrates arranged to face each other. Claim 2
The described liquid crystal display device uses a film substrate having a thickness of about 0.1 to 0.2 mm as the one transparent substrate. The method for manufacturing a liquid crystal display device according to claim 3, wherein when manufacturing a liquid crystal display device in which a color filter is provided on the outer surface of either one of two transparent substrates that are arranged to face each other, one surface of a transparent base film or a polarizing plate is used. To form the color filter by transferring the three color filters of the red, green, and blue resin layers to each other, and to attach the color filter to the outer surface of the one transparent substrate. It is a thing. The method for manufacturing a liquid crystal display device according to claim 4, wherein when manufacturing a liquid crystal display device in which a color filter is provided on the outer surface of one of the two transparent substrates that are arranged opposite to each other, the outer surface of the one transparent substrate is The color filters are formed by transferring filters of three colors including red, green and blue resin layers by transfer.

[0006]

According to the liquid crystal display device of the first aspect, since the color filter is provided on the outer surface of the transparent substrate, the transparent electrode can be directly formed on the inner surface of the transparent substrate, and therefore the conventional protection is provided. The film becomes unnecessary, and the surface of the protective film does not need to be flattened, which facilitates manufacturing. In this case, when a film substrate having a thickness of about 0.1 to 0.2 mm is used as the one transparent substrate as described in claim 2, parallax does not occur. Further, claim 3
Alternatively, according to the method for manufacturing a liquid crystal display device described in 4, by forming each filter of three colors including red, green and blue resin layers on one surface of the base film or the like by transfer,
Since the color filter can be formed, at least the dyeing step is unnecessary, and the number of steps is reduced accordingly.
Can be low cost.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the essential parts of a liquid crystal display device according to an embodiment of the present invention. This liquid crystal display device
An upper film substrate 21 and a lower film substrate 22 are provided. The film substrates 21 and 22 have a thickness of 0.1 to 0.2.
It is made of a transparent resin film such as PET, PES, or polyimide of about mm. Upper film substrate 21
A plurality of transparent electrodes 23 are provided on the lower surface of the so as to extend in the X direction, and an alignment film 24 is provided on the lower surface thereof. A plurality of transparent electrodes 25 are provided on the upper surface of the lower film substrate 22 so as to extend in the Y direction, and an alignment film 26 is provided on the upper surface thereof. Then, the upper film substrate 21 and the lower film substrate 2
2 is bonded to each other via a seal material 27, and a liquid crystal 28 is sealed between them. A polarizing plate 29 is attached to the upper surface of the upper film substrate 21. A base film 32 having a color filter 30 and a black mask 31 is provided on the lower surface of the lower film substrate 22, and a polarizing plate 33 is attached to the lower surface thereof.

Next, a method of manufacturing the color filter 30 portion of the liquid crystal display device will be described with reference to FIG. First, as shown in FIG. 2 (A), PET, PE
A transparent base film 32 made of S, polyimide or the like and having a negative photosensitive red resin layer 41 formed on the upper surface thereof is prepared. As a method of forming the photosensitive red resin layer 41 on the base film 32, for example, FIG.
As shown in, a negative photosensitive resin film 42 dyed red by the pigment dispersion method is laminated on the lower surface of the release film 43. And stage 4
4, the base film 32 is placed on the base film 32, the photosensitive resin film 42 is superposed on the base film 32, and heat and pressure are applied from the upper side of the peeling film 43 by the rolling heating roller 45. Film 4
2 is transferred onto the base film 32. This transfer may be performed using a pair of heating rollers 46, as shown in FIG. Next, after peeling the release film 43,
When the photosensitive resin film 42 is fixed on the base film 32 by heating at about 80 to 200 ° C. in an oven or the like (not shown), the one shown in FIG. 2A is obtained.

Next, a predetermined red photomask 47 is prepared. This red photomask 47 is a glass plate 48.
The mask 49 is formed in a region other than the region corresponding to the stripe-shaped or mosaic-shaped red filter to be formed on the lower surface of the. Then, by exposing from above the negative photosensitive red resin layer 41 using a red photomask 47 and then developing, as shown in FIG. 2B, a red color is formed on a predetermined portion of the upper surface of the base film 32. The filter 50 is patterned in a stripe shape or a mosaic shape.

Next, as shown in FIG. 2C, a negative mold is formed on the upper surface of the base film 32 including the red filter 50 by a method similar to the method shown in FIG. 3A or 3B already described. To form the photosensitive green resin layer 51. next,
A predetermined green photomask 52 is prepared. This green photomask 52 has a structure in which a mask 54 is formed on a lower surface of a glass plate 53 in a region other than a region corresponding to a stripe-shaped or mosaic-shaped green filter to be formed. Then, by exposing from above the negative type photosensitive green resin layer 51 using a green photomask 52 and then developing, a green filter 55 is formed on a predetermined portion of the upper surface of the base film 32 (see FIG. 2D). Are patterned in stripes or mosaics. In this state, the green filter 5 is on the left side of the red filter 50.
5 are formed at regular intervals.

Next, as shown in FIG. 2D, the base film 32 including the red filter 50 and the green filter 55 is formed by a method similar to the method shown in FIG. 3A or 3B already described. A negative photosensitive blue resin layer 56 is formed on the upper surface. Next, a predetermined blue photomask 57
To prepare. The blue photomask 57 has a structure in which a mask 59 is formed on a lower surface of a glass plate 58 in a region other than a region corresponding to a stripe-shaped or mosaic-shaped blue filter to be formed. Then, by exposing from above the negative photosensitive blue resin layer 56 using a blue photomask 57 and then developing, a blue filter 60 is provided on a predetermined portion of the upper surface of the base film 32 (see FIG. 2E). Are patterned in stripes or mosaics. In this state, the blue filter 60 is formed between the red filter 50 and the green filter 55 at a constant interval.

Next, as shown in FIG. 2 (E), a base film including filters 50, 55, 60 of three colors is formed by a method similar to the method shown in FIG. 3 (A) or (B) already described. A negative photosensitive black resin layer 61 is formed on the upper surface of 32. Next, the base film 32 is exposed from below the three-color filters 50, 55, and 60 as a mask, and then developed, as shown in FIG. 2F, between the three-color filters 50, 55, and 60. The black mask 31 is patterned in a stripe shape or a mosaic shape on the upper surface of the base film 32 in FIG. Thus, as shown in FIG. 1, the base film 32 having the color filter 30 and the black mask 31 is obtained. Then, the color filter 30 and the black mask 31 are attached to the lower surface of the lower film substrate 22 via an adhesive (not shown),
Next, the polarizing plate 33 is attached to the lower surface of the base film 32 via an adhesive (not shown).

As described above, in this liquid crystal display device, since the color filter 30 is provided on the lower surface (outer surface) of the lower film substrate 22, the transparent electrode 25 should be formed directly on the upper surface (inner surface) of the lower film substrate 22. Therefore, the conventional protective film is not required, the surface of the protective film is not required to be flattened, and the manufacturing is facilitated. Even if the color filter 30 is provided on the lower surface of the lower film substrate 22, since the thickness of the lower film substrate 22 is about 0.1 to 0.2 mm, parallax does not occur. Furthermore, the color filter 30 is formed by transferring the three color filters 50, 55, 60 of the red, green, and blue resin layers onto the upper surface of the base film 32 by transfer, so that at least the dyeing is performed. The process becomes unnecessary, the number of processes is reduced accordingly, and the cost can be reduced. further,
Since the polarizing plate 33 is provided on the lower surfaces of the color filter 30 and the black mask 31, the polarizing filter 33 can protect the color filter 30 and the black mask 31.

In the above embodiment, the base film 3
2 has a color filter 30 and a black mask 3 on its upper surface.
1, the color filter 30 and the black mask 31 are attached to the lower surface of the lower film substrate 22, and the polarizing plate 33 is attached to the lower surface of the base film 32, but the present invention is not limited to this. For example, as shown in FIG. 4, the color filter 30 and the black mask 31 are formed on the upper surface of the polarizing plate 33 by the same method as in the above embodiment, and the color filter 30 and the black mask 31 are formed.
May be attached to the lower surface of the lower film substrate 22. In addition, the upper film substrate 21 and the lower film substrate 22
Are bonded to each other via the sealing material 27, and after or before the liquid crystal 28 is injected, the color filter 30 and the black mask 31 are directly formed on the lower surface of the lower film substrate 22 by the same method as in the above embodiment. Alternatively, the polarizing plate 33 may be attached to the lower surfaces of the color filter 30 and the black mask 31. Further, the color filter 30 and the black mask 31 may be provided not on the lower surface of the lower film substrate 22 but on the upper surface of the upper film substrate 21. Furthermore, the black mask 31
May be omitted.

[0015]

As described above, according to the liquid crystal display device of the first aspect, since the color filter is provided on the outer surface of the transparent substrate, the transparent electrode can be directly formed on the inner surface of the transparent substrate. Therefore, the conventional protective film becomes unnecessary, and the surface of the protective film does not need to be flattened, which facilitates manufacturing. In this case, when a film substrate having a thickness of about 0.1 to 0.2 mm is used as the one transparent substrate as described in claim 2, parallax does not occur.
Further, according to the method for manufacturing a liquid crystal display device according to claim 3 or 4, by forming each filter of three colors consisting of each resin layer of red, green and blue on one surface of the base film or the like by transfer, Since the color filter is formed, at least the dyeing step is unnecessary, the number of steps is reduced accordingly, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a liquid crystal display device according to an embodiment of the present invention.

2A to 2F are cross-sectional views showing respective manufacturing steps of a color filter portion.

FIGS. 3A and 3B are views for explaining each method when a photosensitive red resin layer is formed on the upper surface of a base film. FIGS.

FIG. 4 is a sectional view of a main part of a liquid crystal display device according to another embodiment of the present invention.

FIG. 5 is a partial cross-sectional view of an example of a conventional liquid crystal display device.

[Explanation of symbols]

 21 upper film substrate 22 lower film substrate 30 color filter 32 base film 33 polarizing plate

Claims (4)

[Claims] 1. A liquid crystal display device, characterized in that a color filter is provided on the outer surface of either one of two transparent substrates which are arranged to face each other. 2. The one transparent substrate has a thickness of 0.1 to 0.
The liquid crystal display device according to claim 1, wherein the liquid crystal display device comprises a film substrate having a thickness of about 2 mm. 3. When manufacturing a liquid crystal display device in which a color filter is provided on the outer surface of either one of two transparent substrates which are arranged opposite to each other, red, green, and
A liquid crystal display device, characterized in that the color filter is formed by transferring three color filters made of blue resin layers, and the color filter is attached to the outer surface of the one transparent substrate. Production method. 4. When manufacturing a liquid crystal display device in which a color filter is provided on the outer surface of either one of two transparent substrates that are arranged to face each other, red, green and blue resins are formed on the outer surface of the one transparent substrate. A method of manufacturing a liquid crystal display device, characterized in that the color filters are formed by transferring filters of three colors each of which is formed by transfer.