JPH11202319A - Color liquid crystal display element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the process resistance and reliability of a color liquid crystal display element having silver salt method color filters. SOLUTION: The color liquid crystal display element having substrates 1, 1', a liquid crystal layer 5 and a color filter layer is constituted by including a silver salt emulsion layer 3 into the color filter layers described above and forming the silver salt emulsion layer 3 only in part (required part) on the substrate 1'. The silver salt emulsion layer 3 consisting of gelatin is formed only on the required part in such a manner, by which the process resistance and reliability of the color liquid crystal display element having the silver salt method color filters are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a color liquid crystal display device used for a color liquid crystal display or the like.

[0002]

2. Description of the Related Art In recent years, with the advancement of the performance of portable electronic devices, there has been a strong demand for higher performance, lighter weight and lower cost of display elements used in these devices. In particular, such a demand for a liquid crystal display element which is excellent as a portable display element is urgent, and the pace of price reduction is particularly fast. Therefore, there is a strong demand for lowering the price of color filters required for high-performance color liquid crystal display devices. However, in general, the manufacturing process of color filters is complicated, and it is difficult to achieve lower prices.

[0003] Actual methods for producing color filters include a dyeing method, a pigment dispersion method, a printing method, an electrodeposition method, and the like, and each is appropriately applied according to required specifications and prices. In contrast, the silver salt method, which is similar to the photographic film technology, has a problem in heat resistance and reliability because a gelatin layer is used as a photosensitive emulsion layer. Not converted.

[0004]

According to the study of the present inventors, the demand for heat resistance of a color filter for a liquid crystal display element is determined by the sintering temperature of a liquid crystal alignment film or overcoat of a color filter, or the firing temperature of a transparent conductive film. Despite the high film formation (or annealing after film formation) temperature, the development of soluble polyimide alignment agents and low-temperature sintering type coating agents, and the lowering of the transparent conductive film formation temperature, the silver salt method The possibility of realizing a color filter based on the above has emerged. In addition, when a polymer film substrate is used, which can reduce the weight and thickness of the liquid crystal display element and enhance the impact resistance, the substrate itself does not have much heat resistance, so the heat resistance required for color filters is also low. Not too harsh.

[0005] Further, the polymer film undergoes a large dimensional change due to heating or moisture absorption. Of the above-mentioned methods for producing a color filter, only the electrodeposition method can cope with this dimensional change together with the silver salt method. Have sex. In other words, in the electrodeposition method, since the conductive film that is first patterned is used as a coloring electrode, even if there is a dimensional change in the substrate during the coloring process, red, green, and blue (hereinafter abbreviated as R, G, and B). Does not cause relative displacement. Further, in the silver salt method, patterning by batch exposure or patterning by intermittent exposure by changing the exposure wavelength without inserting a developing step in the middle can be performed, so that the relative positions of the R, G, B patterns are After all it will be accurate.

As described above, the point that the silver salt method does not require a long time for patterning of R, G, and B is also an advantage in comparison with other color filter manufacturing methods, and it is possible to greatly reduce the cost. Will have sex.

However, when a photosensitive emulsion is applied to a polymer substrate by a conventional method, the photosensitive emulsion is applied to almost the entire substrate. As described above, the photosensitive emulsion layer is composed of a gelatin layer having a thickness of about 10 microns, and such a substrate material cannot be used as a substrate of a liquid crystal display device because of its process resistance and reliability. There is concern. In particular, since the outside of the liquid crystal cell is required to be in direct contact with the outside air and to be connected to an external circuit board, it is preferable that there is no emulsion layer.

The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the process resistance and reliability of a color liquid crystal display device having a silver salt color filter. In addition, it is an object of the present invention to provide a color liquid crystal display device excellent in productivity and portability.

[0009]

According to a first aspect of the present invention, there is provided a color liquid crystal display device having a substrate, a liquid crystal layer and a color filter layer, wherein the color filter layer is formed of silver. A salt emulsion layer is provided, and the silver salt emulsion layer is formed only on a part (necessary part) of the substrate. As described above, by forming the silver salt emulsion layer made of gelatin only on a necessary portion on the substrate, it becomes possible to improve the process resistance and the reliability of the color liquid crystal display device having the silver salt color filter. .

According to a second aspect of the present invention, in a color liquid crystal display device having a substrate, a liquid crystal layer and a color filter layer, the color filter layer includes a silver salt emulsion layer. An unnecessary portion is removed. Thus, by removing unnecessary portions of the silver salt emulsion layer made of gelatin, it becomes possible to improve the process resistance and the reliability of the color liquid crystal display device having the silver salt method color filter.

A third aspect of the present invention is the color liquid crystal display device according to the first or second aspect, wherein a polymer film is used as the substrate. As described above, even when a polymer film is used as a substrate, by forming or leaving a silver salt emulsion layer only on a part of the polymer film, the resistance of a color liquid crystal display device having a silver salt method color filter can be improved. The processability and reliability can be improved, and a color liquid crystal display element excellent in productivity and portability can be provided.

According to a fourth aspect of the present invention, in the color liquid crystal display device of the first or third aspect, a part of the substrate is subjected to a hydrophobic treatment before forming the silver salt emulsion layer. Thus, a silver salt emulsion layer is provided only on a part of the substrate. As described above, before the silver salt emulsion layer is applied, a portion of the substrate surface where the silver salt emulsion layer is not necessary is subjected to a hydrophobic treatment, and the silver salt emulsion layer is not applied to the portion, whereby the silver salt method is applied. It is possible to improve the process resistance and reliability of a color liquid crystal display device having a color filter.

According to a fifth aspect of the present invention, in the color liquid crystal display device according to the first or third aspect, a part of the substrate is subjected to a hydrophilic treatment before forming the silver salt emulsion layer. Thus, a silver salt emulsion layer is provided only on a part of the substrate. As described above, before the silver salt emulsion layer is applied, a portion of the substrate surface where the silver salt emulsion layer is required is subjected to a hydrophilic treatment, and the silver salt emulsion layer is partially applied, whereby the silver salt method color is applied. It is possible to improve the process resistance and reliability of the color liquid crystal display device having a filter.

According to a sixth aspect of the present invention, in the color liquid crystal display device according to the first or third aspect, a portion of the substrate is masked before forming the silver salt emulsion layer. A silver salt emulsion layer is provided only on a part of the substrate. In this way, before coating the silver salt emulsion layer, the portion of the substrate surface where the silver salt emulsion layer is not required is masked, and the silver salt emulsion layer is not coated on that portion, so that the silver salt color filter can be used. It is possible to improve the process resistance and reliability of the liquid crystal display element having the above.

According to a seventh aspect of the present invention, in the color liquid crystal display device according to the second or third aspect, after forming the silver salt emulsion layer on the substrate, a part of the silver salt emulsion layer is removed by an etchant. It is characterized by having done. As described above, by removing a part of the unnecessary silver salt emulsion layer on the substrate by the etchant, it is possible to improve the process resistance and reliability of the liquid crystal display device having the silver salt color filter.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, a configuration example of a color liquid crystal display element will be described. FIG. 2 is a diagram schematically showing a cross section when a color liquid crystal display device is constituted by using a color filter produced by the same method as a general photographic color film. As shown in FIG. 2, in this color liquid crystal display device, an upper substrate 1 and a lower substrate 1 'provided with a silver salt emulsion layer (hereinafter referred to as an emulsion layer) 3 for forming a color pattern.
Between them, a liquid crystal layer 5 and an upper electrode 2 and a lower electrode 2 ′ for applying a drive voltage to the liquid crystal layer 5 are provided. On the surface of the emulsion layer 3, an overcoat 7 is required as a protective layer. The sealant 4 is arranged so as to surround the liquid crystal layer 5, and sandwiches the liquid crystal in a space surrounded by the upper and lower substrates 1, 1 ′ and the sealant 4 to form the liquid crystal layer 5.

In some cases, an alignment film for aligning liquid crystal molecules is required on the upper and lower interfaces of the liquid crystal layer 5, but is omitted in the figure because it is unnecessary for a polymer dispersion type liquid crystal display device or the like. Also, in order to keep the distance between the upper and lower substrates constant, glass or plastic beads,
Spacers made of fiber and photoresist are arranged, but these are not shown.

In the structure of the color liquid crystal display device shown in FIG. 2, the portion 6 where the upper and lower substrates 1 and 1 'do not overlap is outside the liquid crystal cell and is exposed to the outside air. Such a portion outside the cell 6 is necessary for connecting the lower electrode 2 ′ to the drive circuit. This is the same for the upper electrode 2. The upper substrate 1 and the upper electrode 2 are provided with a portion protruding from the lower substrate 1 'in the direction toward or behind the plane of FIG. The connection is made. Therefore, in FIG. 2, the same configuration is obtained even if an emulsion layer is provided on the upper substrate 1 side.

In the color liquid crystal display device having the above-mentioned structure, in the present invention, the emulsion layer 3 is formed only on a part (necessary part) of the substrate, or the unnecessary part of the emulsion layer 3 is removed. It is characterized by doing. Hereinafter, specific examples will be described.

(Embodiment 1) First, an embodiment corresponding to claim 1 or 2 will be described. FIG. 1 is a diagram showing a configuration example of a color liquid crystal display device according to the present invention, in which (A) is a plan view showing a coating range of an emulsion layer on a lower substrate of the color liquid crystal display device;
(B) is a schematic sectional view of a color liquid crystal display element. FIG.
A hatched portion 10 of the lower substrate 1 'shown in FIG. 2A is a portion where the emulsion layer 3 is not coated and where no emulsion layer is coated, and the portion 10 where the emulsion layer is not coated is a portion of the cell exterior 6 shown in FIG. Are provided substantially corresponding to FIG. 1B shows a cross section when a color liquid crystal display element is formed using a substrate provided with such an emulsion layer non-coating portion 10, and the portion 6 outside the cell is only the emulsion layer non-coating portion 10. Thus, the emulsion layer 3 is not exposed to the outside air outside the cell, and the connection with the driving circuit can be made in a portion where the emulsion layer 3 is not provided on the base.
In the example shown in FIG. 1B, the emulsion layer 3 on the lower substrate 1 '
Of the lower electrode 2 ′ is formed in a gentle taper shape to prevent disconnection of the lower electrode 2 ′.

(Embodiment 2) Next, another embodiment corresponding to claim 1 or 2 will be described. FIG. 3 is a schematic sectional view showing another configuration example of the color liquid crystal display element according to the present invention. FIG.
In the embodiment of (B), an example is shown in which the end of the emulsion layer 3 on the non-coating portion 10 side is tapered. However, when it is difficult to form such a tapered shape, As shown in FIG. 3, a treatment such as providing a flattening layer 12 (hatched portion in the figure) in advance on the surface of the non-emulsion layer-coated portion 10 of the lower substrate 1 'is possible. The flattening layer 12 can be formed by partial application of a resin, patterning of a photoresist, or the like.

(Embodiment 3) Next, an embodiment corresponding to claim 2 will be described. As an example of another method for forming a structure in which the emulsion layer 3 is not provided in an unnecessary portion as in the color liquid crystal display device shown in FIG. 1B or FIG. 3, as shown in FIG.
(A) First, the emulsion layer 3 is formed on the entire surface or almost the entire surface of the substrate.
(B) Then, a part of the emulsion layer 3 is removed to form an emulsion layer removed portion 13. According to this method, the step of coating the emulsion layer can be performed by a conventional method or apparatus, which has a merit in cost. Further, the quality and thickness of the emulsion layer can be easily controlled.

(Embodiment 4) Next, an embodiment corresponding to claim 3 will be described. In the color liquid crystal display device of each of the above embodiments, when the substrate on which the emulsion layer is provided is a polymer film, the emulsion layer is roll-coated by a film winding type emulsion coating apparatus as illustrated in FIG. And productivity is remarkably improved. The emulsion coating apparatus shown in FIG. 5 has a configuration in which the emulsion is applied while the polymer film substrate 20 wound around the substrate delivery roller 15 is wound up by the substrate winding roller 17 via the heating roller 16. Before reaching the heating roller 16, the emulsion solution flowing out from the emulsion outlet 18 of the emulsion container 19 is applied onto the emulsion-free polymer film substrate 20 sent from the substrate sending roller 15,
It is dried by heating with a heating roller 16 and wound up by a winding roller 17.

In order to fix the layer structure of the emulsion layer on the polymer film substrate 20 formed near the emulsion outlet 18 of the emulsion container 19, it is preferable to insert a cooling step before coating and heating. In some cases (for example, a cooling roller is provided between the substrate delivery roller 15 and the emulsion outlet 18). The shape and number of the rollers are described here as the most basic ones.
Such a process is the same as a general photographic film production process, except that the present invention does not apply or leave the emulsion layer on the entire surface of the substrate, but coats or removes a portion of the emulsion layer, thereby obtaining a liquid crystal film. It can be used as a substrate.

A color liquid crystal display device manufactured using a color filter using a polymer film as a substrate in this way is thin, lightweight, and has improved portability. Even when broken, there is no danger like glass, and from this point, it is particularly preferable for portable use.

(Embodiment 5) Next, an embodiment corresponding to claim 4 will be described. In the color liquid crystal display device of each of the above embodiments, since the material of the emulsion layer applied to the substrate is hydrophilic gelatin, the application of the emulsion layer is generally performed as an aqueous gelatin solution. For this reason, when the substrate surface is hydrophobic, an emulsion layer is not easily formed in that portion. Therefore, a method in which an emulsion layer is unnecessary, such as the non-emulsion layer coating portion 10 in FIG. 1 or the emulsion layer removal portion 13 in FIG. Can be used. If the original substrate surface is not hydrophilic, the entire surface of the substrate may be previously subjected to a hydrophilic treatment, and then unnecessary portions of the emulsion layer may be subjected to a hydrophobic treatment. In order to make the surface of the substrate hydrophobic, treatment or application with a coupling agent, application of a hydrophobic resin or oil or the like is performed.

(Embodiment 6) Next, an embodiment corresponding to claim 5 will be described. Contrary to Example 5, when the surface of the substrate is not very hydrophilic, a method of subjecting a portion to be coated with an emulsion layer to a hydrophilic treatment can be used. When the hydrophobicity of the original substrate surface is insufficient, it is also possible to previously hydrophobize the entire surface of the substrate and then hydrophilize the portion to which the emulsion layer is to be applied. In order to make the substrate surface hydrophilic, treatment or application with a coupling agent, application of a hydrophilic resin, corona discharge treatment, treatment with an acid or alkali solution, ultraviolet irradiation, or the like is performed.

(Embodiment 7) Next, an embodiment corresponding to claim 6 will be described. In producing a color liquid crystal display device according to the present invention, as a method of coating an emulsion layer only on a part of a substrate, there is a method of masking a portion not requiring an emulsion layer. The masking material is preferably a material that can be easily peeled off later, and a release film with a thin adhesive is preferred. A film substrate maker attaches such a release film as a protective film and partially supplies it as a protective film, and materials used for these can be used.

Incidentally, a masking film (release film)
Depending on at which stage of the process, the material that can be used is restricted, but if a high-temperature process up to about 120 ° C. is entered before peeling, the material that can be used as a masking film material is It has a certain degree of heat resistance, such as polyethylene terephthalate, polypropylene, polyimide and polyetherimide.

As one of the simplest methods, there is a method in which a part of a protective film of a substrate supplied with a protective film is peeled, and an emulsion layer is applied to the peeled part.

(Embodiment 8) Next, an embodiment corresponding to claim 7 will be described. Gelatin used for the material of the emulsion layer is easily dissolved in warm water unless particularly subjected to a hardening treatment. Therefore, as shown in FIG. 4, a method for removing an unnecessary portion of the emulsion layer of the substrate is to form the emulsion layer 3 on the substrate 1 'and then wash the portion 13 not requiring the emulsion layer with warm water. Part of the emulsion layer can be partially removed. Further, it is easily dissolved in an aqueous solution of an oxidizing agent such as sodium perchlorate, and by using such a solution as an etchant, an unnecessary portion of the emulsion layer can be removed.

[0032]

As described above, in the color liquid crystal display device according to the first aspect, since the silver salt emulsion layer made of gelatin is formed only on a part (necessary part) of the substrate, the silver salt method is used. Process resistance and reliability of a color liquid crystal display device having a color filter can be improved.

In the color liquid crystal display device according to the present invention, since unnecessary portions of the silver salt emulsion layer made of gelatin are removed, the process resistance and reliability of the color liquid crystal display device having the silver salt method color filter are removed. Can be improved.

In the color liquid crystal display device according to the third aspect, even when a polymer film is used as the substrate,
By forming or leaving a silver salt emulsion layer only on a part of the polymer film, it is possible to improve the process resistance and reliability of a color liquid crystal display device having a silver salt color filter, and to improve productivity and A color liquid crystal display element having excellent portability can be provided.

In the color liquid crystal display device according to the fourth aspect, before applying the silver salt emulsion layer, a portion of the substrate surface where the silver salt emulsion layer is unnecessary is subjected to a hydrophobic treatment, and the portion is coated with silver. By not coating a salt emulsion layer, the process resistance and reliability of a color liquid crystal display device having a silver salt color filter can be improved.

In the color liquid crystal display device according to the present invention, before the silver salt emulsion layer is coated, a portion of the substrate surface where the silver salt emulsion layer is required is subjected to a hydrophilic treatment, and the silver salt emulsion layer is partially formed. By coating the emulsion layer, the process resistance and reliability of a color liquid crystal display device having a silver salt color filter can be improved.

In the color liquid crystal display device according to the present invention, before coating the silver salt emulsion layer, a portion of the substrate surface where the silver salt emulsion layer is unnecessary is masked, and the silver salt emulsion layer is applied to the portion. By not applying a layer, the process resistance and reliability of a liquid crystal display device having a silver salt color filter can be improved.

In the color liquid crystal display device according to the present invention, after forming a silver salt emulsion layer on a substrate, an unnecessary part of the silver salt emulsion layer on the substrate is removed by an etchant, so that a silver salt method color liquid crystal display device. The process resistance and reliability of a liquid crystal display device having a filter can be improved.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing a configuration example of a color liquid crystal display device according to the present invention, wherein FIG. 1A is a plan view showing a coating range of an emulsion layer on a lower substrate of the color liquid crystal display device, and FIG. It is a schematic sectional drawing of a display element.

FIG. 2 is a schematic sectional view showing a configuration example of a general color liquid crystal display element.

FIG. 3 is a schematic sectional view showing another configuration example of the color liquid crystal display element according to the present invention.

FIG. 4 is an explanatory diagram of a case where an emulsion layer is formed on a substrate and then partially removed.

FIG. 5 is a schematic diagram illustrating an example of a film winding type emulsion coating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper substrate 1 'Lower substrate 2 Upper electrode 2' Lower electrode 3 Silver salt emulsion layer 4 Sealant 5 Liquid crystal layer 6 Cell exterior 7 Overcoat layer 10 No emulsion layer coating part 11 Emulsion layer taper part 12 Flattening layer 13 Emulsion layer Removal unit 15 Substrate feeding roller 16 Heating roller 17 Substrate winding roller 18 Emulsion outlet 19 Emulsion container 20 Polymer film substrate

Continuation of front page (72) Inventor Yasuyuki Takiguchi 1-3-6 Nakamagome, Ota-ku, Tokyo, Ricoh Co., Ltd.

Claims (7)

[Claims] 1. A color liquid crystal display device having a substrate, a liquid crystal layer and a color filter layer, wherein the color filter layer includes a silver salt emulsion layer, and the silver salt emulsion layer is partially formed on the substrate. Necessary part)
A color liquid crystal display device characterized by being formed only on a liquid crystal display device. 2. A color liquid crystal display device having a substrate, a liquid crystal layer and a color filter layer, wherein the color filter layer includes a silver salt emulsion layer, and unnecessary portions of the silver salt emulsion layer are removed. A color liquid crystal display device characterized by the above-mentioned. 3. A color liquid crystal display device according to claim 1, wherein a polymer film is used as said substrate. 4. The color liquid crystal display device according to claim 1, wherein before the silver salt emulsion layer is formed,
A color liquid crystal display device, wherein a silver salt emulsion layer is provided only on a part of the substrate by subjecting a part of the substrate to a hydrophobic treatment. 5. The color liquid crystal display device according to claim 1, wherein before the silver salt emulsion layer is formed,
A color liquid crystal display device, characterized in that a silver salt emulsion layer is provided only on a part of the substrate by subjecting a part of the substrate to a hydrophilic treatment. 6. The color liquid crystal display device according to claim 1, wherein before the silver salt emulsion layer is formed,
A color liquid crystal display device, wherein a silver salt emulsion layer is provided only on a part of the substrate by masking a part of the substrate. 7. A color liquid crystal display device according to claim 2, wherein after forming said silver salt emulsion layer on said substrate, a part of said silver salt emulsion layer is removed by an etchant. Liquid crystal display element.