JPS647674B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a high-density information display device such as a matrix type liquid crystal display device having orthogonal strip-shaped electrodes, a so-called matrix electrode structure, and in particular, the present invention relates to a cell terminal connection structure. The drive of a matrix type liquid crystal display device, for example, a line sequential scanning method, is constructed as shown in FIG. That is, the main memory device 1 stores characters, symbols, figures, patterns, etc., and this stored data is converted into a display pattern by the character signal converter 2, and is sent to the buffer memory in the column drive circuit 3 for each row of the display screen. After storing the data in the column electrodes, the outputs thereof are supplied to the column electrodes Y ₁ , Y ₂ , . . . _Yo , respectively. Row electrodes X ₁ , X ₂ ,
..., X _n are sequentially driven by the row drive circuit 4,
The information stored in the buffer memory is displayed line by line. In the figure, numeral 5 is a control device for controlling the operations of the column drive circuit and row drive circuit, and 6 is a liquid crystal display device having matrix type electrodes. In this matrix type liquid crystal display device, the greater the number of lines, the higher the display density and the better the display accuracy.However, as the number of lines increases, the time for applying a signal to one line, that is, the duty, decreases, and crosstalk ( Problems such as cross effect) will occur. In particular, when a liquid crystal is used as a display element, sufficient contrast cannot be obtained because the characteristics of the liquid crystal are that the threshold value is not steep and the response is slow. In order to solve these problems, the following various measures have been devised. Development of liquid crystal materials with clearer threshold characteristics. The drive margin (α=Von/Voff) is increased by further optimizing the matrix addressing method. Improve the apparent resolution by improving the electrode structure. _{For example} , as _{shown in FIG} .
The row electrodes X ₁ , X ₂ , . . . _, X _n are made common to the upper and lower column electrodes. or Figure 2b
For one row electrode X _j , adjacent column electrodes Y _i and Y _j are interposed alternately in a comb shape, as shown in FIG. Although the above method does not require changing the structure of the liquid crystal cell, it cannot be expected to dramatically increase the number of lines that can be driven. Although this method complicates the structure of the liquid crystal cell, it can reliably increase the number of drivable lines by 2, 3, 4, etc. The present invention improves the complicated electrode structure and makes the structure simple and easy to implement. There are two possible structures for matrix liquid crystal cells that can produce the electrode structure shown in FIG. 2a. One is a structure in which the column electrodes are divided into upper and lower parts within the same cell (upper and lower division matrix method), and the other is a structure in which the column electrodes are divided into upper and lower parts.
There is a two-layer structure (two-layer matrix method) in which sets of liquid crystal cells are stacked one on top of the other. The present invention relates to the latter two-layer matrix method. 2
To explain the layer matrix method in more detail, as shown in Figure 3, the first layer is
a transparent substrate 11, a second transparent substrate 12, and a third transparent substrate 11;
The first substrate 1 is constructed by sequentially stacking substrates 13 of
1 is provided with column electrodes 14a, 14b, . . .
Row electrodes 15a, 15b, . . . are provided on the upper half of the surface of the substrate 12 facing the first substrate 11. Row electrodes 16a, 16b, . . . are provided on the lower half of the second substrate 12, which faces the third substrate.
Column electrodes 17a, 17b, . . . are provided on the third substrate. This two-layer matrix method has the advantage of being able to reliably double the duty compared to other methods. However, (a) since there are two layers of cells, parallax occurs, so to prevent this, the substrate located in the center of the three substrates must be made as thin as possible. Although glass plates are commonly used as substrates, thin glass plates are at high risk of being damaged during handling during the manufacturing process. (b) It is very difficult to draw out the electrodes from the row electrodes of such a thin glass plate for connection to the drive circuit, and there is a risk that the glass plate may be damaged. (c) When the electrodes of each electrode are alternately drawn from both ends of the glass plate, it is necessary to draw the electrodes from eight positions, and the electrode drawing positions overlap, making the structure of the electrode drawing complicated. Implementation problems such as these may occur. An object of the present invention is to provide a terminal processing structure for a multilayer liquid crystal display device that solves these problems. FIG. 4 is a plan view and a sectional view taken along the line A-B of an embodiment of the two-layer matrix system used in the present invention, and a cross-sectional view taken along the line C-D.
A line cross-sectional view is shown. When the display part (including the seal part 30) is made up of three transparent glass substrates 21, 22, and 23, the dimensions are a and b, and the width of the electrode extension part is c,
The dimensions of the three glass substrates are shown in Table 1 below. (However, c does not need to be all the same.)

[Table] And only the lower half of the glass substrate 21 has row electrodes 2.
4a, 24b, . . . are provided. Glass substrate 22
Column electrodes 25a, 25b, ... are provided on the display surface side, and row electrodes 26a, 26 are provided only in the upper half on the opposite side.
b,... are provided. Column electrodes 27 are provided on the substrate 23.
a, 27b, . . . are provided. The electrode extension parts 28, 28 of the electrode 24 are formed in the lower half of both sides of the substrate 21. Electrode extension part 2 of electrode 25
9 and 29 are formed on both vertical parts of the display surface side of the substrate 22, and electrode extension parts 31 and 31 of the electrode 26 are formed on the upper halves of both horizontal parts of the substrate 22. Electrode extension parts 32, 32 of the electrode 27 are formed on both vertical parts of the substrate 23. A liquid crystal 33 is filled between the substrates 21 and 22 to form a first liquid crystal cell, and a liquid crystal 34 is filled between the substrates 22 and 23 to form a second liquid crystal cell. With the above structure, the liquid crystal display device used in the present invention has the electrode structure shown in FIG. 2a in plan view, and the two-layer matrix display cell shown in FIG. 3 in cross section is completed. In this way, the liquid crystal display device used in the present invention is made by sequentially stacking substrates with increasing vertical (or horizontal) widths and decreasing horizontal (or vertical) widths. The electrode extension part 29 of the thin glass substrate 22 which is sandwiched between the substrates is in contact with the rear substrate 23, and the electrode extension part 31 is supported in contact with the front substrate 21, and as shown in FIG. 30 to below the electrode extension part 31, the substrate 22
The strength equivalent to that of the substrates 21 and 23 can be obtained. Therefore, even if the electrodes are drawn out from the electrode extension parts 29 and 31 of the substrate 22 using a flexible sheet or an electrode bottle, the glass will not be damaged. 8 again
The multiple electrode extensions do not overlap.
In this way, multi-layer liquid crystal display elements can increase the number of display pixels compared to the same multiplex, but on the other hand, there are still problems such as differences in level at the terminals and contact during connection. . The present invention has been made in this regard, and provides effective terminal connection by making the shape of the circuit board (glass epoxy board or ceramic board) complementary to the shape of the terminal portion of the display element. This is a proposal for technology that can be used. An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 6 shows one embodiment of the present invention using a multilayer liquid crystal display device using a twisted nematic liquid crystal display mode, in which numerals 45 and 35 are polarizing filters, and numeral 36 is a reflecting plate. . Note that the reflective plate may be formed directly on the circuit board 37. The circuit board is a multilayer printed circuit board made of the following materials:
Ceramic boards with high-resolution wiring capabilities are suitable. Reference numeral 38 denotes a contact pad installed in correspondence with the liquid crystal display element terminal of the circuit board, and may be made of any material with good conductivity such as Au. 39 is
This is a through-hole wiring, and is used to connect the signal from the pad 38 to the drive element (IC) 41 on the other side. Note that 40 is wiring, 47 is wire bonding, and 48 is a protective sealing material. 42 is an elastic connector;
Examples include anisotropic conductive rubber sheets such as Comerix Type 1705, Oki Electric Cable H Grade, Shin-Etsu Polymer Polymer AF Type, and Toray Elastic Connector. 43 indicates a conductor portion formed in the elastic connector 42. 44 is a band for fixing the display element section and the circuit section. Fig. 7 is a view of Fig. 6 from the direction A, and 38'' and 38 are pads, but any material that can be soldered may be used, and they do not necessarily have to be Au, but may be Ni, Cu, etc. etc. 49 is
This is solder that connects the pad and the flexible sheet 50, and is connected to the liquid crystal element through the conductor 51 glued to the flexible sheet 50. Since 38" and 38 are not on the same plane, they do not affect each other electrically or mechanically. Also, in FIG. 6, since the distance between their connecting surfaces is the same, 38" Another feature is that the same type of conductive elastic connector can be used for the terminal processing section 3 on the circuit board 37 side.
Glass substrates 21, 2 on 8, 38', 38'', 38
By forming complementary steps corresponding to the steps of the electrode extension portions formed sequentially at the ends of 2 and 23, terminal processing of a multilayer liquid crystal display element can be performed effectively and reliably, and the display It becomes possible to downsize the entire device. Furthermore, the same connection member can be used between each connection portion for electrical connection between the circuit board and the liquid crystal display cell, and there is no need to perform special forming processes such as bending the connection member.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic structure of a conventional matrix type liquid crystal display device. Figure 2a,
FIG. 1b is a diagram showing an improved structure of the matrix electrode. FIG. 3 is a perspective view showing the structure of a two-layer matrix type liquid crystal display device. Fourth
Figures a, b, and c are a plan view, an AB sectional view, and a CD sectional view of a two-layer matrix system according to an embodiment of the present invention. FIG. 5 is a sectional view of a main part showing the configuration of the seal portion in FIG. 4. FIG. 6 is a sectional view of essential parts of a multilayer liquid crystal display device showing one embodiment of the present invention. FIG. 7 is a sectional view of the main part viewed from direction A in FIG. 6. 38...Compact pad, 39...Through hole wiring, 41...Drive element, 42...Elastic connector, 43...Band.

Claims (1)

[Claims] 1. A plurality of glass substrates are stacked so that the vertical width becomes sequentially larger and the horizontal width becomes smaller sequentially, and the gap between the glass substrates is filled with a liquid crystal layer, and the glass substrate has a row on the lower surface in the vertical direction for applying a voltage to the liquid crystal layer. and one of the column electrodes are arranged, and external connection lead terminals are successively exposed to the outside for each glass substrate near the end in the vertical direction, and the other of the row and column electrodes is arranged on the upper surface in the horizontal direction, and the other one of the row and column electrodes is arranged in the horizontal direction. In a terminal structure of a multilayer liquid crystal display device in which external connection lead-out terminals are sequentially exposed outward for each glass substrate near an end, a power supply circuit board for the row and column electrodes is arranged to overlap with the glass substrate. A step difference corresponding to a step difference between the lead terminals of each glass substrate provided and formed by both the row and column electrodes is formed complementary to the step difference,
A power supply pad surface facing and electrically connected to the lead-out terminal located near the lower end of each of the glass substrates is formed at each step of the circuit board, and is sequentially arranged at substantially equal intervals with the lead-out terminal. A power supply pad surface electrically connected to the lead-out terminal located near the upper end of each of the glass substrates is formed at each step of the circuit board and is approximately at the same level as each of the corresponding lead-out terminals. A terminal structure for a multilayer liquid crystal display device, characterized in that the terminal structure is arranged at a height at which an electrical connection can be made.