JPS6023826A - Display device - Google Patents

Abstract

PURPOSE:To enable manufacture of a display device having high display quality by using the films formed by electrodepositing an electrodepositable high polymer on the conductive layers from a soln. prepd. by dispersing said high polymer in water for insulation between the patterns neighboring with each other of electrodes. CONSTITUTION:A display device is made into the construction in which the 1st base plate 2 and the 2nd base plate 4 respectively having electrode patterns are held at a specified space via spacer 5 and a display material 10 is sandwiched between said plates. Films 9 formed by electrodepositing an electrodepositable high polymer on conductive layers from a soln. prepd. by dispersing said high polymer in water are utilized for insulation between the patterns neighboring with each other of the electrodes 1, 1' in the above-mentioned constitution.

Description

[Detailed description of the invention] The present invention relates to a display device.

A display device based on the XY matrix method which is currently widely used is, as shown in FIG. 4, the striped pattern transparent electrodes 1 and 6 are maintained at a constant interval via a spacer 5 so as to be perpendicular to each other, and a display material 6 is sandwiched between them. However, in such an electrode structure, it is necessary to provide a certain amount of space between the stripes, and this gap remains as an area where no display can be performed, causing deterioration in display quality. As shown in Figure 2, the part corresponding to the gap in the electrode pattern appears as a gap between pixels,
The effective area of the display screen 7 becomes small.

Conventionally, in order to improve these points, as shown in FIG.
After forming every other striped electrode, a transparent iO2 film 8 is formed as an insulating film over the entire surface of these striped transparent electrodes by vacuum distillation or sputtering, and then on top of this transparent insulating film. In addition, by producing a new transparent electrode 1' to exactly fill in the area not covered by the pattern of the lower layer transparent electrode 1, a display device that can effectively utilize the entire display screen has been produced.

However, in these conventional methods, since the transparent insulating film used between adjacent transparent electrode patterns is 5i02, pinholes are created during film formation.9 - The film cracks due to the heat applied to the process element. This often results in poor insulation between patterns, and it is actually very difficult to obtain a display with no gaps between pixels.

In order to eliminate the above-mentioned drawbacks, the present invention provides a transparent insulating film that is formed by electrodepositing a conductive layer between adjacent transparent electrodes from a solution in which an electrodepositable polymer is dispersed in water. The purpose is to easily produce display devices with high display quality.

This polymer film is easy to produce, has a thin and uniform film thickness, has good transparency, and is dense and has no pinholes.
It is characterized by high insulation properties. Here, a method for forming an insulating layer by electrodeposition of a polymer, which is an important point of the present invention, will be described. As a method for electrodepositing a polymer on an electrode, there is a method in which the polymer is insolubilized and precipitated on the electrode from a polymer solution. As an example of this, a method called electrodeposition coating, in which a pigment is dispersed in an aqueous polymer solution, a metal is immersed, used as an electrode, and a colored layer is electrodeposited on the metal is known industrially. , used for pre-coating of automobile bodies, etc. The principle of this method is to introduce a hydrophilic group, such as a carboxyl group, into a polymer, and then neutralize the carboxyl group with an inorganic alkali, organic amine, etc. to make it water-soluble. Then, when the electrode is immersed in an aqueous solution of the polymer in a water bath and a voltage is applied, the carboxyl anions dissociated in the aqueous solution electrophores toward the anode and react with protons generated by electrolysis of water on the electrode. As a result, the polymer becomes insolubilized and precipitates out.

That is, the reaction shown in the following formula occurs on the anode, and polymer precipitation is observed.

2 H20-94H, + 02 ↑+4e-Also, if a basic group (e.g. polyamine) is used as the hydrophilic group and it is neutralized with acid and made water-solubilized, polymer precipitation can be observed on the cathode. It turns out.

If the electrodeposited polymer is electrically insulating, the current decreases as the electrode is coated with the polymer, and the increase in film thickness is expected to be negligible because the coating of more than 7L can be prevented.
In reality, the initial complete coating is avoided due to the bubbles of oxygen generated by the decomposition of water, and a certain degree of film thickness is obtained by the time it becomes an insulating layer. Normally, 100% for electrodeposition coating.
A film thickness of 10 to 20 .mu.m was obtained by applying a voltage of .about.200 V, but when the purpose is to obtain an insulating film with high accuracy and fineness as in the present invention, the thinner the insulating layer is, the desirably about 1 .mu.m. For this purpose, the resin concentration,
It is necessary to optimally set the voltage and solvent composition. The polymer membrane thus obtained has a low water content due to the effect of electroosmosis, and is a uniform membrane with good adhesion compared to membranes produced by coating methods or the like.

Examples of polymers for anionic electrodeposition include adducts of natural drying oil and maleic acid, alkyd resins with carboxyl groups introduced, adducts of epoxy resins with maleic acid, polybutadiene resins with carboxyl groups, acrylic acid or methacrylic acid, etc. A copolymer with the ester thereof is used, and depending on the characteristics of the electrodeposited film, other polymers or organic compounds having functional groups may be introduced into the molecular skeleton. Acrylic or polyester polymers are suitable when appearance, such as transparency and gloss, are important. In addition, the amount of hydrophilic functional groups such as carboxyl groups and hydroxyl groups in the polymer is important; if there are too many hydrophilic groups, the electrodeposition layer will not be sufficiently insolubilized, resulting in an uneven film, and if there is too little, it will be difficult to neutralize. water solubility becomes insufficient. Water is the main component as a solvent for polymers, but isopropanol, n-7'f alcohol, t-
Hydrophilic solvents such as polyalcohol, butyl cellosolve, ethyl cellosolve, inglovir cellosolve, butyl cellosolve, diethylene glycol methyl ether, diethylene glycol ethyl ether, and diacetone alcohol are included as solvents for polymerization of polymers. The type and amount of the hydrophilic solvent contained greatly influences the film thickness and uniformity of the electrodeposited layer.

By this method, a film that is thin and uniform in thickness, has good transparency, and has high insulation properties can be easily produced.

Hereinafter, the present invention will be explained in detail based on Examples.

1) As shown in FIG. 4(a), a 5n02 film is formed as a transparent electrode on a transparent substrate 2 by an OVD method or a sputtering method, and then a striped transparent electrode 1 is produced by chemical etching.

At this time, if the stripe width of the transparent electrode 1 and the stripe interval are made equal, the shape of the purple image displayed will be a square when the XY matrix display device is finally assembled. Next, on the transparent substrate 2 having the striped transparent electrodes 1, as shown in FIG. It was formed on the transparent electrode 1 by electrodeposition from a bath in which it was dispersed in water.

Coating Composition Butyl Cellosolve 1 A platinum plate was used as the counter electrode, and a voltage of 20 V was applied for 3 minutes. When this is cured at 175° C. for 30 minutes, a transparent insulating film is formed. Next, the polymer transparent insulating film created as above? a transparent substrate 2 having a transparent electrode 1 covered with
A 5n02 film is formed over the entire surface by OVD or sputtering, and the Sn02 film in the portion of the display screen covered with the transparent electrode 1 is removed by chemical etching. As shown in FIG. 4(C), a striped transparent electrode 1' can be obtained. Through the steps described above, as shown in FIG. 4(c),
We were able to fabricate striped transparent electrodes with seemingly no gaps between the electrodes. After going through the same process as above, using an electrodeposited polymer film as a transparent insulating film, as shown in Fig. 4 (0).
Striped transparent electrode 3 with no gaps between the electrodes shown in
After fabricating the striped transparent electrode 1 on the transparent substrate 2
1' and the striped transparent electrodes 5 on the substrate 4 are kept at a constant distance via a spacer 5 so that they are perpendicular to each other, and a nematic liquid crystal Kj10 is sandwiched between them, as shown in FIG. 4(d). A TN type liquid crystal display device as shown was completed. By applying an appropriate voltage between the transparent electrodes 1 and 1' on the transparent substrate 2 of this liquid crystal display device and the transparent electrode 3 on the substrate 4 to display a certain figure, as shown in FIG. A beautiful display with no visible gaps between the electrodes could be obtained on the display screen 7.

In the above process, the etching of 5n02N may be dry etching such as reverse sputtering.

ll) Conventionally, numbers have been displayed using the 7 shown in Figure 6.
Segment electrodes are used. However, in this electrode structure, there are gaps between segments.
It can be said that there is still room for improvement in display quality. Therefore, it is possible to adopt the present invention in which an electrodeposited polymer film is used as a transparent insulating film. First, as shown in FIG. 7, segments a(11), g(17), d(14
) is made of a 5n02 film, and then an electrodeposited polymer film is formed as an insulating film in the same manner as in Example 1). Subsequently, segments b(12), C(13), e(15), f
(16) When a liquid crystal cell was assembled using the i5nn2 film, a beautiful display with no visible gaps between segments was obtained as shown in FIG.

As described above in Example 1) and 0, the electrodeposited polymer film used as the transparent insulating film in the present invention has the conventional B j, 0
Compared to two-layer films, it has the advantage of creating a dense layer without pinholes during film formation, and the trench manufacturing process is simple, resulting in a high-quality display that eliminates gaps between display electrodes. It is extremely effective in producing devices.

[Brief explanation of drawings]

FIG. 1 shows a 1° cross section of a conventionally known XY matrix type display device, and FIG. 2 shows a plan view thereof. FIG. 3 shows a sectional view of another conventionally known XY matrix type display device. FIG. 4 is a process diagram showing a method for manufacturing a display device according to the present invention. Figure 85 shows a plan view of the tampering device according to the present invention. Figure 6 shows the conventional 7-segment type display! S:
Government. 7 and 8 show a seven segment type display device K according to the present invention. 1.1', 3... Transparent electrode 2... Death, 5 pieces 14... Substrate 5... Sube length -6... ... Display material 7 ... Display 1 to surface 8 ... 5nO1 film 9 ... Electricity 7+
"j Polymer film 10... Nematic liquid crystal layer 11... Segment a 12... Middle segment:
/ G1) 13...Segment c 14...
...Segment d15...Segment θ 1
6...Segment f17...Segment g Fig. 2 Fig. 4iJl (Q) Fig. 4 (Fig. 4 (C) Fig. 4 (d) 1 1°58 Fig. 1,! 13-

Claims (1)

[Claims] In a display device in which a first substrate and a second substrate each having an electrode pattern are maintained at a constant distance via a spacer, and a display material is sandwiched between them, insulation between adjacent patterns of the electrodes is provided. A display device characterized by using a film formed by electrodepositing an electrodepositable polymer on a conductive layer from a solution in which it is dispersed in water.