JPH0640181B2 - Liquid crystal display - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid crystal display device for connecting a large-sized full-dot liquid crystal display element in which a large number of extraction electrodes are arranged at an ultrafine pitch to an external circuit.

[Conventional technology and problems]

Conventionally, the following structure has been used for connecting a liquid crystal display element and an external circuit. FIG. 1 is a perspective view of a connection structure used when the electrode terminal pitch is wide in the prior art, and a liquid crystal display element 1 and an external circuit are connected by a metal wire 2. Although this structure enables accurate connection, it cannot be used in a liquid crystal display device having a fine pitch because the adjacent electrodes are likely to come into contact with each other.

FIG. 2 is a perspective view of a conductive rubber connector according to the prior art, and FIG. 3 is a perspective view showing a connection structure between a liquid crystal display device and an external circuit board with the conductive rubber connector of FIG. 2 interposed. is there. As shown in FIG. 3, a conductive rubber connector in which the conductive rubber portions 3 and the insulating rubber portions 4 are alternately combined at a fine pitch is used as an electrode 7 formed on the liquid crystal display element extraction electrode 5 and the circuit board 6. Are placed so as to intervene between the two electrodes, and a mechanical pressure is applied between the both electrodes to electrically connect the both electrodes. At present, the pitch of the conductive rubber portion 3 has become considerably fine, but when this structure is used in a large liquid crystal display element having an electrode pitch of about 0.4 mm and an ultrafine pitch of about 600 electrodes, The lead electrode 5 of the liquid crystal display element whose substrate material is glass and the electrode 7 formed on the circuit board whose substrate material is glass epoxy resin cause a slight pitch shift due to the difference in shrinkage due to heat, and the liquid crystal display element. It is difficult to make an electrical connection at the ends.

In this case, it is considered that the pitch deviation due to heat gradually increases toward the end of the array when the central part of the array of the extraction electrodes 5 is used as a reference. Therefore, the pitch between the respective extraction electrodes 5 and the electrodes 7 is increased. Based on the center
It is considered that it may be configured so that it gradually becomes larger toward the end. However, it is not realistic to change the pitch of a large number of electrodes respectively, because it is extremely difficult in actual work.

[Object of the Invention]

An object of the present invention is to solve the problems as described above and to increase the number of steps in a liquid crystal display device in which a large number of extraction electrodes arranged at an ultrafine pitch can be easily connected to an external circuit. There is no simple way to provide.

Example of Invention

Hereinafter, the present invention will be described in detail based on examples. Fourth
FIG. 1 is a perspective view of a liquid crystal display element according to an embodiment of the present invention. As shown in FIG. 4, the pitch of the lead-out electrodes 5 of the liquid crystal display element 1 is set near the center of the liquid crystal display element 1 and that of the liquid crystal display element 1. The electrode on the external circuit board is changed at the same pitch as that of the cell so that P ₂ is larger than P _{1 and} patterned at the end so that P ₂ is larger than P _1. . Then, as shown in FIG. 3, a conductive rubber connector having a fine pitch is interposed, and the cell and the external circuit board are connected to each other by mechanical pressure with reference to the cell center. In this case, since the electrode pitch is larger toward the edges, it is possible to connect the liquid crystal display element and the external circuit at the edge even if there is some misalignment, and the difference in heat shrinkage due to the material difference between the liquid crystal display element and the external circuit board. It was possible to eliminate the pitch deviation caused by. Therefore, it becomes possible to easily align the liquid crystal display element extraction electrode with the electrode on the external circuit board.
Also, instead of a conductive rubber connector as a connector,
Even when heat seal is used, by setting the heat seal pattern as shown in FIG. 4, the liquid crystal display element-heat seal connection and heat seal-external circuit board connection can be performed accurately without pitch deviation, as in the above result. I can do well.

As described above, it is not in the central portion of the liquid crystal display element that is difficult to make a reliable electrical connection due to thermal deformation, but in the end portion or the like, which is mainly apart from the central portion. Therefore, the electrodes may be arranged at a pitch different from that of the central portion only for a portion where electrical connection may be unstable.

In this case, the risk of unstable connection varies depending on the position of the electrode, but changing the pitch for each electrode having a different risk poses various difficulties not only in the design but also in other steps. Therefore, it is efficient to divide the arrangement of the electrodes into some blocks and arrange a plurality of electrodes at the same pitch in each block to reduce the number of different pitches as much as possible.

FIG. 4 is a simplest embodiment based on the above idea,
In the vicinity of the central portion, the electrodes are arranged in blocks having a constant pitch P1, and the electrodes are arranged in blocks having a pitch P2 at the ends. That is, in FIG. 4, by combining two types of blocks having different pitches, all electrodes are arranged in three blocks.

Of course, the number of blocks may be further increased if necessary.

〔The invention's effect〕

As described above, according to the liquid crystal display device of the present invention, the connection between the liquid crystal display element and the external circuit board is facilitated, and a large full-dot liquid crystal module in which a large number of lead electrodes are arranged at an ultrafine pitch can be used. It is possible to assemble in a short time, and since there is almost no increase in the load in the design and other processes in the implementation, it can be easily implemented in a wide variety of models, so it is reliable and inexpensive. It greatly contributes to the provision of liquid crystal display devices.

[Brief description of drawings]

FIG. 1 is a perspective view showing a conventional liquid crystal display device with a metal wire,
FIG. 2 is a perspective view showing a conventional conductive rubber connector, FIG. 3 is a perspective view showing a connection structure between a liquid crystal display element and an external circuit board with a conventional conductive rubber connector interposed, and FIG. 1 is a perspective view of a liquid crystal display device according to an exemplary embodiment of the present invention. 1 ... Liquid crystal display element, 2 ... Metal wire, 3 ... Conductive rubber part, 4 ... Insulating rubber part, 5 ... Extraction electrode of liquid crystal display element, 6 ... Circuit board, 7 ... Circuit board Electrodes formed on top.

Claims (1)

[Claims] 1. A liquid crystal display device configured such that the pitch in the arrangement direction of a plurality of extraction electrodes is larger at the end portion than at the central portion, at least near the central portion of the electrode arrangement. A liquid crystal display device characterized in that a portion in which the pitch of four or more adjacent electrodes is constant is provided.