JPH0651318A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To ameliorate the nonuniformity of display occurring in the difference in the distance from a driving circuit. CONSTITUTION:The grain sizes of particulate spacers 11a, 11b, 11c for maintaining the spacing between a pair of transparent substrates 1 and 2 constituting the liquid crystal display element at a prescribed value by interposing between these substrates 1 and 2 are changed so that the spacing between the substrates 1 and 2 is smaller in the part where the distance from the driving circuit 8 is larger. As a result, the variations in impressed voltages and variations in display density by the difference in the distance from the driving circuit 8 are compensated and the optimum driving voltage within the display plane is equaled. The liquid crystal display element having the uniform display is thus obtd.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A liquid crystal display device has a structure in which a pair of transparent substrates are opposed to each other at a predetermined interval and a liquid crystal substance is enclosed between them, and a fine particle spacer is used to keep the interval between the substrates at a predetermined value. It is known to
-73152 gazette). FIG. 5 is a schematic diagram showing the structure. In the figure, 1 is a scanning substrate, 2 is a signal substrate, which is a transparent insulating substrate on which stripe-shaped scanning electrodes 3 and signal electrodes 4 are formed, respectively. A liquid crystal alignment film is also formed on these substrates 1 and 2, but it is not shown in the drawing. 5 is a liquid crystal substance, 6 is a spacer, and 7 is a sealing material. The liquid crystal substance 5 and the spacer 6 are sealed between the substrates 1 and 2 and the periphery of the substrate is sealed with the sealing material 7. The spacer 6 is in the form of fine particles and has a size of several μs corresponding to the substrate spacing.
The spacing between the substrates 1 and 2 is kept at a predetermined value by arranging the ones having an average diameter of m so that the distribution density becomes uniform.

By the way, when such a liquid crystal display device is used, a driving circuit 8 such as an IC device is connected to each of the electrodes 3 and 4 as shown in FIG. The liquid crystal substance 5 reacts, but as the distance from the drive circuit 8 increases, that is, in FIG.
In the case of (a), the applied voltage between the electrodes decreases from the upper right to the lower left due to the resistance of the electrodes 3 and 4, and the display density becomes uneven between the upper right and the lower left. Note that this is a problem similarly occurring in a liquid crystal display device that does not use the fine particle spacers 6. In order to solve this display nonuniformity, it is conceivable to increase the film thickness of the scanning electrode 3 and the signal electrode 4, for example. However, this lowers the transmittance of the electrodes, which lowers the brightness, and the film formation However, there is a demerit such as an increase in cost, which is a limit, and it is not sufficient as a measure for improving display unevenness.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve such a display nonuniformity problem, and pays attention to fine particles used as spacers to improve the display. I am trying to

[0005]

In order to solve the above-mentioned problems, according to the present invention, a liquid crystal display device having the above-mentioned structure, that is, a fine particle spacer between a pair of transparent substrates each having a transparent electrode. In the liquid crystal display device in which the two substrates are opposed to each other with a predetermined gap therebetween and the liquid crystal substance is sealed between the substrates, the transparent electrodes are connected to each other at a portion where the distance from the drive circuit is large. The particle size of the spacers is changed according to the distance from the drive circuit so that the distance between the two becomes smaller.

[0006]

The transparent substrates are arranged in a non-parallel arrangement such that the distance between the substrates is small in the portion where the distance from the drive circuit is large. Therefore, the thickness of the liquid crystal layer formed between the substrates changes, and variations in applied voltage and variations in display density due to differences in distance from the drive circuit are compensated for, and the optimum drive voltage can be made substantially equal. It becomes possible and the display becomes uniform.

[0007]

Next, an embodiment of the present invention will be described. The same parts as those of the conventional example shown in FIG. 5 are designated by the same reference numerals. First, the manufacturing procedure is described. About 1000 Å ITO as a transparent electrode is attached to a glass plate as a transparent substrate.
After forming a film with a thickness of 1, the stripe electrodes are formed by the photolithography and etching methods, and the liquid crystal alignment film made of polyimide is further formed to obtain the scanning substrate 1 and the signal substrate 2. Next, one of the substrates 1 or 2 is sprinkled with spacers from above with the alignment film side facing up. In the conventional example, one kind of spacer is sprinkled so that the in-plane distribution density becomes uniform. In contrast, spacers having different particle sizes are used in the present invention.

The spacers can be dispersed by the method shown in FIG. For example, when using three types of spacers having a particle size of spacer 11a <spacer 11b <spacer 11c, each nozzle 12a for supplying them is used.
As shown in FIG. 3, 12b and 12c are arranged along the diagonal line of the substrate 1 or 2 in order from the farthest distance from the drive circuit 8, and the spacers 11a, 11b and 11c are dispersed in appropriate amounts. The arrangement of each nozzle and the supply amount of each spacer are selected so that each spacer 11a, 11b, 11c has a density distribution as shown in FIG. 4, and after spraying, the other substrate 2 or 1 is bonded with a sealing material 7. The liquid crystal substance 5 is injected and sealed. As a material for the spacer, any insulating material having a small variation in particle diameter and having an average particle diameter corresponding to the target thickness of the liquid crystal layer can be used. The spherical polymer resin material sold by Sekisui Fine Chemical Co., Ltd. is particularly suitable, and is also a preferable material as a spacer for a liquid crystal display element in the present invention because it is transparent.

FIG. 1 is a schematic sectional view of the liquid crystal display device obtained by the above procedure, and FIG. 2 is a plan view thereof, but the basic structure is the same as that of the conventional example of FIG. This is different from the conventional example in that the scanning substrate 1 and the signal substrate 2 are not perfectly parallel but are slightly inclined because the particle diameters of the spacers 11a, 11b, and 11c differ depending on the distance from. That is, since the distance between the substrates 1 and 2 becomes smaller as the distance from the drive circuit 8 increases, even if the applied voltage between the electrodes 3 and 4 at the time of operation becomes lower in the part farther from the drive circuit 8 due to the resistance of the electrodes, The gap between the electrodes 3 and 4 is reduced to compensate for the decrease in applied voltage, and the display on the entire display surface is made uniform.

The combination of the particle diameters of the spacers used is determined by the resistance of the electrodes, the size of the display surface, the type of liquid crystal material, and the like.
b and 11c have particle sizes of 6.5, 6.75 and 7.0.
μm is used, and its distribution density is, for example, 1 mm ²
It is selected to be 65 to 95 pieces. When the thickness of the liquid crystal layer is different, the display density becomes uneven when no voltage is applied.
If it is 0.6 μm or less, there is no problem in practical use, and if the particle size difference is within the above range, there is no problem.

In FIG. 3A, an example in which a partition plate 13 is provided between the nozzles is shown, and in FIG. 3B, a film 14 having a slit 14a is provided between the nozzle and the substrate and the slit 14a is provided. An example is shown in which the spacers 11a, 11b, 11c are sequentially sprayed while the position is moved in the arrow direction. By providing the partition plate 13 or the film 14 in this way, the distribution density of the spacers can be easily adjusted. Further, in the above-mentioned embodiment, the case where the spacer has three kinds of particle diameters has been explained, but the particle diameter may be two kinds or four kinds or more, and these can be used in an appropriate combination.

[0012]

As is apparent from the above-described embodiments, the present invention is interposed between a pair of transparent substrates constituting a liquid crystal display device and is used for keeping a distance between the substrates at a predetermined value. The particle size of the fine-particle spacers is changed so that the distance between the substrates is reduced in the portion where the distance from the drive circuit is large. Therefore, the thickness of the liquid crystal layer formed between the substrates is changed according to the distance from the drive circuit, and variations in applied voltage and display density due to different distances are compensated for and the optimum drive voltage in the display surface is adjusted. Can be made equal. Therefore, it becomes easy to obtain a liquid crystal display element having a uniform display, and it is effective in improving the display nonuniformity particularly in a liquid crystal display element having a large display surface size.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an embodiment of the present invention.

FIG. 2 is a schematic plan view of the same embodiment.

FIG. 3 is a diagram showing an example of a spacer spraying method in the embodiment.

FIG. 4 is a diagram showing an example of a distribution density of dispersed spacers.

5A and 5B are a schematic plan view and a schematic sectional view of a conventional example.

[Explanation of symbols]

 1 Scanning Substrate 2 Signal Substrate 3 Scanning Electrode 4 Signaling Electrode 5 Liquid Crystal Material 7 Sealing Material 8 Driving Circuit 11a, 11b, 11c Spacer 12a, 12b, 12c Nozzle

Claims (1)

[Claims] 1. A liquid crystal comprising a pair of transparent substrates each having a transparent electrode, and a fine particle spacer interposed between the substrates so that the substrates are opposed to each other with a predetermined gap therebetween, and a liquid crystal substance is sealed between the substrates. In the display element, the particle diameter of the spacer is changed according to the distance from the drive circuit so that the distance between the substrates is small in the portion where the distance from the drive circuit to which each transparent electrode is connected is large. Liquid crystal display device.