JPH0324523A - Electrooptical display cell - Google Patents

Abstract

PURPOSE:To prevent unequal colors and unequal contrasts by conducting and connecting the dummy electrodes of one substrate to the electrode or dummy electrodes facing thereto another substrate. CONSTITUTION:The one substrate 1 is constituted by having the parts formed with the dummy electrodes 7, 7a which do not contribute to a display. The other substrate 3 has the electrode 4 or dummy electrodes 7b facing at least partly the dummy electrodes 7, 7a. Conductive particles 8 are incorporated into a seal 5 and the dummy electrodes 7, 7a, 7b and the counter electrodes 2, 4 thereof are extended to the region of the seal 5. The dummy electrodes and the counter electrodes thereof are conducted and connected via the conductive particles 8 incorporated into the seal 5. The same potential is maintained in the dummy electrodes and the counter electrodes facing thereto. The electrooptical display cell which obviates the unequal thickness of the inter- substrate spacing and the change in the inter-substrate spacing by the force of static electricity and is free from the unequal colors and unequal contrast is obtd.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to electro-optic display cells.

[Background Art] In recent years, electro-optical devices such as liquid crystal display devices have been viewed as promising as display devices capable of displaying large screens with low power consumption.

The above-mentioned liquid crystal display element is a typical example, but especially recently, with the demand for higher display speeds, it has become necessary to obtain devices with narrower spacing between substrates than before. is now needed. Control of such narrow substrate spacing is especially important because if the thickness unevenness of the substrate spacing is large, color unevenness etc. will become noticeable and will likely cause product defects.

One of the causes of thickness unevenness in the spacing between substrates that often becomes a problem is thickness unevenness caused by the thickness of electrodes between areas where electrodes are present and areas where electrodes are not present on the substrate.

In order to prevent such thickness unevenness from occurring, conventionally, dummy electrodes made of the same conductive film as the electrodes are provided even in parts of the substrate where no electrodes are present, to prevent thickness unevenness between the substrates caused by the presence or absence of electrodes. It was being prevented.

[Problems to be Solved by the Invention] By the method described above, it is possible to suppress thickness unevenness in the substrate spacing due to the presence or absence of electrodes. However, due to the use of an electro-optical display element, a substrate made of an insulator is easily charged with static electricity, and this force often causes thickness unevenness.

[Means for Solving the Problem] The present invention has been made to solve the problem, and includes an electro-optic medium sandwiched between a pair of substrates provided with electrodes, and the periphery of which is sealed with a sealing material. In the electro-optical display cell, one of the substrates has a portion formed with a dummy electrode that does not participate in display, and the other substrate has an electrode or a portion at least partially opposed to the dummy electrode. The present invention provides an electro-optical display cell characterized in that it has a dummy electrode, and the dummy electrode on one substrate is electrically connected to the opposing electrode or dummy electrode on the other substrate.

Hereinafter, the configuration of the present invention will be explained using an example in which the present invention is applied to a liquid crystal display cell.

FIG. 1 is a top view of the arrangement of electrodes on a pair of substrates when the present invention is applied to a liquid crystal display cell, viewed from the same direction, with (A) being the upper substrate and (B) being the lower substrate. This is the side board. Further, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, showing the pair of substrates laminated and pressure-bonded via a sealing material. In the figure, 1 and 3 are substrates, 2 and 4 are display electrodes, 5 is a peripheral seal, 6 is a liquid crystal layer, and 7, 7a, and 7b are dummy electrodes.

In the present invention, it is preferable that an electrode be provided so as to cover almost the entire surface of the substrate as shown in FIG. 1, or a lead wire or a dummy electrode for taking the electrode out of the cell. That is, it is preferable that a dummy electrode be provided also in a portion of the substrate opposite to the lead wire, and further, a dummy electrode and a dummy electrode opposite thereto be provided also in a portion where no electrode is required for display. In addition, the dummy electrodes are provided not only within the display surface where the display is actually performed, but also in the periphery as shown in Figure 1, so that the substrate is almost covered with the electrodes, their lead wires, and the dummy electrodes. It is preferable to do this because the spacing between the cell substrates becomes more constant as a whole.

In FIG. 1, 7 indicates a dummy electrode facing the display electrode 2 or 4, and 7a and 7b indicate a pair of dummy electrodes facing each other. As can be seen from FIG. 1, the dummy electrode always has a counter electrode at least partially opposite it. The opposing electrode may be a display electrode or its lead wire, or may be a dummy electrode, but in any case, the dummy electrode is configured to have opposing north poles.

In the present invention, the dummy electrode is electrically connected to its counter electrode. To explain the conductive connection method using the example shown in FIGS. 1 and 2, conductive particles 8 are mixed into the seal 5, and a dummy electrode and its counter electrode are extended to the area of the seal 5. It depends on what you do. That is, the dummy electrode and its counter electrode are electrically connected via the conductive particles 8 mixed in the seal 5.

This conductive connection does not necessarily have to be made within the seal; it is also possible to extend the dummy electrode and its counter electrode to the outside of the cell using lead wires, and to make conductive connection to each other outside the cell. However, if the conductive connection is made within the seal as in this embodiment, the conductive connection can be easily made even when the pitch of the electrode pattern becomes fine, and the reliability is also high, which is preferable. In addition, when making a conductive connection in this way using conductive particles in the seal, the size of the conductive particles should be approximately the same as the diameter of the spacer that is normally mixed into the sealing material. This is more preferable since it can also serve the same role.

It should be noted that conventional methods can be applied to the manufacturing method of the above-mentioned liquid crystal display element, and various changes can be made as long as the effects of the present invention are not impaired.

[Example] Similar to FIG. 1, electrodes made of indium tin oxide were patterned on two substrates (one substrate had 400 row electrodes, and the other substrate had 400 row electrodes perpendicular to the row electrodes). 640 column electrodes) were provided in the direction. At this time, dummy electrodes were provided even in areas unnecessary for display in order to maintain a constant thickness between the substrates. From above, the film thickness is 0.
．． A 1 um thick polyimide film was formed and rubbed to form an alignment film. After that, a sealing material mixed with a spacer is applied to one substrate by screen printing, and a sealing material mixed with conductive particles is applied to the other substrate by screen printing at a position where the above dummy electrode and its counter electrode are conductively connected. Formed by printing. Thereafter, the above-mentioned electrode substrates were bonded by thermocompression via the above-mentioned sealing material to form an empty cell, and liquid crystal was sealed in the cell to form a liquid crystal cell. The liquid crystal display device using the obtained liquid crystal cell had an extremely good appearance without color unevenness due to uneven thickness of the substrate spacing.

[Effects of the Invention] According to the present invention, since the electrodes and dummy electrodes are provided on the entire surface of the substrate, it is possible to eliminate thickness unevenness in the distance between the substrates caused by the presence or absence of electrodes. Since they are conductively connected, they have the same potential, and there is no thickness unevenness or change in substrate spacing due to electrostatic force, and an electro-optical display cell without color unevenness or contrast unevenness can be obtained.

Further, according to the invention according to claim 2, since the electrodes and dummy electrodes are provided on the entire surface of the substrate, the color of the electrodes provided on the substrate can be seen uniformly, and the appearance of the electro-optic display cell is improved. do.

Furthermore, according to the invention according to claim 3, it is possible to easily establish a conductive connection between the dummy electrode and the electrode facing it even with a very fine electrode pattern, and it is also possible to obtain a highly reliable connection. .

[Brief explanation of drawings]

FIG. 1 is a top view of the arrangement of electrodes on a pair of substrates when the present invention is applied to a liquid crystal display cell, viewed from the same direction, with (A) being the upper substrate and (B) being the lower substrate. This is the side board. Further, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, showing the pair of substrates laminated and pressure-bonded via a sealing material. 1, 3... Substrate 2, 4... Electrode 5... Seal 6... Liquid crystal layer 7... Dummy electrode 8... Conductive particles 8 1 Mother name 2 Diagram

Claims (3)

[Claims] (1) In an electro-optic display cell in which an electro-optic medium is sandwiched between a pair of substrates provided with electrodes and the periphery is sealed with a sealing material, one of the substrates is not used for display. The other substrate has an electrode or dummy electrode at least partially opposite to the dummy electrode, and the dummy electrode of one substrate has a portion on which a dummy electrode is formed.
An electro-optical display cell characterized in that it is electrically connected to the electrode or dummy electrode on the other substrate opposite thereto. (2) The electro-optical display cell according to claim 1, wherein opposing surfaces of the pair of substrates are substantially covered with electrodes, their lead wires, and dummy electrodes. (3) The dummy electrode on one substrate and the opposing electrode or dummy electrode on the other substrate are electrically connected to each other by conductive particles mixed in a sealing material. The electro-optic display cell according to claim 2.