JPS5912483A - Terminal processing system for matrix display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a matrix terminal connection system comprising a group of orthogonal strip-shaped electrodes.

In a matrix type liquid crystal display device, the larger the number of lines, the higher the display density and the better the display quality, but as the number of lines (number of scanning lines) increases, the time for applying a signal to one line, that is, the duty, decreases. Also, the margin for crosstalk decreases. In particular, it is difficult to obtain sufficient contrast because the transmittance-voltage characteristics of the liquid crystal used as the display medium are not steep and the response (response speed) is slow. The following measures have been proposed to solve these problems. Development of a liquid crystal material with a clear applied voltage lamp light transmittance characteristic of f1+threshold. (2) Drive margin (α) by optimizing the matrix addressing method
=Von/voff).

(3) Improve the apparent resolution by improving the electrode structure.

For example, as shown in FIG. 1(A), the signal side electrode is
'+ Y2. ”'+Yn and lower side Y'1. Y'2 , -
, Y'n, and scanning side electrodes x, , x2 . ...,
Either make Xm common to the upper signal side electrode and the lower signal side electrode, or use one scanning side type as shown in FIG. 1(B)y!
The signal side electrodes Yj and Yj+1 in @ contact with Xi are inserted in a comb shape. Alternatively, as shown in FIG. 2, there is a method in which a plurality of liquid crystal panels are stacked one on top of the other, row electrodes 2 and column electrodes 3 are arranged on the inner surface of the cells of the glass substrate 1 in a vertically divided manner for each cell, and each is driven individually. (1) and (2) above
) method does not require changing the structure of the liquid crystal panel, but it cannot be expected to dramatically increase the number of lines that can be driven. On the other hand, method (3) makes the structure of the liquid crystal panel more complicated, but it also ensures that the number of lines that can be driven is doubled.
It can be increased by 2 times... Method (3) can greatly increase the number of lines that can be driven, but
The number of terminal electrodes on the signal side electrodes also increases by 2 times, 22 times, and so on. If method (3) is adopted, the number of terminals will increase dramatically, but as an example of this terminal processing method, the edge of the wiring board on which the liquid crystal drive circuit element is mounted is bent and anisotropically conductive rubber is used to terminal the terminal. There is a method for making electrical connection with a liquid crystal panel that is connected in series. In this method, as shown in FIG. 3, a liquid crystal cell is constructed using a glass substrate 1, and a signal side electrode 4 and a scanning side electrode 5 are arranged on the inner surface of the cell, and a liquid crystal 6 is connected to both electrodes 4.
A liquid crystal panel is formed by interposing between the electrodes 4 and 5 and sealing the cell periphery with a sealing material 7, and terminals of both electrodes 4 and 5 are extended to one surface of the glass substrate outside the liquid crystal panel to form an anisotropic A conductive rubber (elastomer) 8 is interposed and a connector 9 electrically and mechanically connects the ends of a wiring board 10 on which a drive circuit is attached. In this method, circuit element 1
The scanning side electrode 5 connected to the wiring board 10 on which the LCD panel 1 is mounted is provided under the wiring board 10, and it is very important to insert the anisotropically conductive rubber 8 between the liquid crystal panel 1 and the wiring board 10. It was troublesome. In addition, in a matrix liquid crystal panel consisting of multiple lines, it is difficult to transfer electrodes to one substrate using a transfer material, and terminal electrodes are provided on opposing surfaces of separate substrates, so this method is difficult. This makes it difficult to mechanically fix the liquid crystal panel and the wiring board using the scanning side electrode 5. The present invention aims to provide a new and useful terminal processing method for a matrix display device that solves the above-mentioned problems.The present invention will be described in detail according to embodiments with reference to the drawings. FIGS. 4 to 7 are configuration diagrams of a terminal connection system between a liquid crystal panel and a wiring board, each showing an embodiment of the present invention. In the figure, the same reference numerals as in Figure 3 indicate the same contents.0 Either the scanning side electrode or the signal side electrode is made of conductive rubber with anisotropic conductivity, as in the conventional case, to connect the liquid crystal panel and the wiring board electrically. However, the remaining terminal is electrically connected using a flexible wiring sheet.

In each embodiment, a case will be described in particular in which a flexible wiring sheet is used for terminal processing of scanning side electrodes.

The method shown in FIG. 4 uses a flexible wiring sheet 12 with through-holes on both sides, since the terminal electrodes on the liquid crystal panel side are exposed on the top surface of the glass substrate, and the terminal electrodes on the wiring board side are exposed on the top surface of the substrate. It is. This system has the disadvantage that the flexible wiring sheet (12) provided with through holes on both sides is expensive, which increases the cost. Further, if the terminal pitch of the scanning side electrodes becomes very fine, a problem arises in that through holes cannot be formed in the flexible wiring sheet 12. For this reason, the connection method shown in FIG. 5 is an embodiment in which the connection between the liquid crystal panel and the wiring board is improved by using a relatively inexpensive flexible wiring sheet 13 having electrodes formed on only one side. In the embodiment shown in Figure 6, the edge of the wiring board where the scanning side electrodes are provided is bent in the direction closer to the liquid crystal panel in the same way as the signal side, so that it is at almost the same height as the scanning side electrodes of the liquid crystal panel. Then, the flexible wiring sheet 13 is bent outward again and the edge of the wiring board is connected to the liquid crystal panel using a flexible wiring sheet 13. The embodiment shown in FIG. 7 is a method in which the edge of the wiring board is bent in the direction closer to the liquid crystal panel and then connected to the flexible wiring sheet 13.

The material for the flexible wiring sheet 12.18 is a conductive material containing carbon or silver in a thermoplastic resin such as phenol resin, and a wiring sheet (hereinafter referred to as a thermal wiring sheet) printed on a polyester film using a screen printing method. (referred to as crimp wiring sheet). Since this wiring sheet is made of thermoplastic resin, it can be easily adhered to a glass substrate or a wiring board by heating the part to be adhered to a temperature of about 180°C and applying pressure at the same time. Another material is a wiring sheet (hereinafter referred to as polyimide wiring sheet) which is made by photo-etching a copper foil on a polyimide film that has excellent heat resistance. It can be connected to a board and a wiring board. A specific method of connecting the above two types of flexible wiring sheets to the glass substrate and the wiring board will be explained. First, in the case of a thermocompression bonded tile distribution sheet, the heated head 1
4 is pressed down with compressed air, and the part to be thermocompressed is heated and pressurized. First, the connection with the liquid crystal panel is made, and then the connection with the wiring board is made. It is also possible to connect both at the same time by providing a spacer with an appropriate thickness. Next, in the case of a polyimide wiring sheet, as shown in Figure 9, the light source 1
From step 5, first connect the liquid crystal panel and the polyimide wiring sheet. After that, connection to the wiring board is made.

As explained in detail above, by bending the edge of the wiring board on which the circuit section for driving the liquid crystal panel is constructed toward the liquid crystal panel side and using conductive rubber having conductive anisotropy and a flexible wiring sheet, the liquid crystal panel and the wiring can be connected. Since the substrates are integrally bonded, it is possible to obtain a small and thin matrix display device that makes full use of space without requiring particularly difficult manufacturing techniques.

[Brief explanation of drawings]

FIGS. 1A and 2B are electrode configuration diagrams of a conventional matrix electrode structure liquid crystal display device. FIG. 3 is a configuration diagram illustrating a connection structure between a liquid crystal panel and a wiring board. FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are configuration diagrams of a terminal connecting portion each showing one embodiment of the present invention. FIG. 8 is an explanatory diagram illustrating a method of connecting thermocompression wiring sheets. Figure 9 shows polyimide electrodes, 6...liquid crystal layer, 8...conductive anisotropic comb, 9...connector, 10...wiring board,
12.18...Flexible wiring sheet. Agent Patent attorney Aihiko Fukushi (and 2 others) 3 Figure 2 Figure 4 / (,1 Figure 5 Iυ Figure 6

Claims (1)

[Claims] 1. In a matrix display device consisting of a matrix type display panel having a matrix electrode structure and a wiring board on which a driving circuit for driving the display panel is provided, the edge of the wiring board is arranged in a direction in which the edge of the wiring board approaches the display panel. The connection wiring of the drive circuit is extended to the edge and electrically connected to the terminal electrode of one electrode group of the matrix electrode using conductive rubber having anisotropic conductivity. A terminal processing method for a matrix display device, characterized in that the terminal electrodes of the other electrode group of the matrix electrodes and the connection wiring are electrically connected by a flexible wiring sheet.