JPH04155377A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To reduce the number of assembly processes and to realize a thin type display device of a low cost and furnishing a back light by including a power source circuit in a substrate for driving a scanning electrode, and crossing it with a substrate for driving a signal electrode in two levels. CONSTITUTION:An output signal from a controller is input to a YM substrate 6 through an input cable 1. To the YM substrate 6, ICs for driving a scanning electrode and for a power source are mounted. The output terminal of the substrate 6 is connected to the output terminal and the input terminal of an X substrate 4 to which an LSI to drive a signal electrode is loaded, by a flat cable 9. In this case, the mounting height of parts mounted to the substrate 6 is made up to the size A, and the allowable height of parts can be set higher than in a conventional structure. By such a constitution, the number of substrates is reduced, and low cost parts can be used.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to the structure of a liquid crystal display device.

[Conventional technology]

In recent years, space saving has been emphasized for personal use of office automation equipment, and as a result, there has been an increasing demand for space saving, especially thinner, liquid crystal display devices. Here, an example of making a conventional liquid crystal display device thinner will be explained with reference to FIGS. 4 and 5.

Signals from the controller for driving the liquid crystal panel 5 enter from an input cable 1 into a board 2 (hereinafter referred to as the M board) on which a power supply circuit for creating potential levels for the liquid crystal is mounted.
This X substrate 2 transmits necessary signals to the input substrate 3 (hereinafter referred to as the Y substrate) of the flexible substrate on which the LSI driven by the scanning electrode is mounted, and the LSI that drives the signal electrode.
Input board 4 (hereinafter referred to as X
It is separated into signals necessary for the circuit board (called a substrate). As shown in FIG. 5, the X board 4 is fixed to the light guide 7 so as to wrap around the light guide 7 of the backlight, and the Y board 3 is fixed to the backlight plastic case 8 on the same plane as the liquid crystal panel 5. placed on top. Also MJIFi,
2 is fixed to a plastic case 8 facing the Y board 3.

By covering the unit described above with a metal frame, a thin liquid crystal display device with a backlight having a total thickness of about 10 mm could be provided.

[Problem to be solved by the invention]

However, in the prior art described above, one X board, one
This requires a total of four boards, including one board and two X boards, which is one of the causes of high costs. Also, there is one connection between the M board and the Y board.
The M board to the This was caused by backlight failure due to the adverse effects of the heat. Furthermore, X
Since the board and the X board face each other, the height of the components mounted on the X board is restricted, making it difficult to use low-cost components.

SUMMARY OF THE INVENTION The present invention is intended to solve these problems, and its purpose is to provide a thin liquid crystal display and claw device with a backlight that requires fewer assembly steps and can be realized at low cost.

[Means to solve the problem]

The liquid crystal display device of the present invention has L for driving the scanning electrode.
The input circuit board of the flexible board on which the SI is mounted also includes an electric FArgJ path, and the input circuit board of the flexible board on which the LSI for driving the signal electrode is mounted also includes a circuit board for driving the scanning electrode. It is characterized by a three-dimensional intersection with the input board of the flexible board on which the LSI is mounted.

〔Example〕

FIGS. 1(a) to 1(b) are diagrams showing the structure of a liquid crystal display device of the present invention. Here, (a) is a view seen from the display surface side,
(b) is a diagram seen from the back side of the display surface. 1 is a cable for inputting signals from the controller, 4 is an X board, 5 is a liquid crystal panel, and 6 is a Y that serves as both an X board and an X board.
There is an MX board.

FIG. 2 is a sectional view taken along the line AA in FIG. 1. Here, 7 is a light guide for the backlight, 8 is a plastic case that serves as a light guide holder for the backlight and a liquid crystal panel holder, and 9 is a flat cable.

Here, the configuration of the liquid crystal display device of the present invention will be briefly described.

Input signals from the controller are input to the YMX board through input cable 1. The YMX board is equipped with many components such as a power IC, aluminum electrolytic capacitor, ceramic capacitor, and resistor for creating potential levels for the liquid crystal and for logic signals. This YMX board is X board 4
There are 21 terminals for outputting signals to the LCD panel 4, and by connecting them to the input terminals of the X board 4, all the signals necessary for displaying the liquid crystal panel 5 are supplied.

Here, the structure of the present invention will be explained in detail.

As shown in FIG. 2, the X substrate 4 intersects the upper side of the YMX substrate with a certain space. The connection between the YMX board and the X board 4 is such that the above-described YM board vi6 and the output terminal and input terminal of the X board 4 are connected by a flat cable 9.

Here, the YMX board will be explained in detail. The mounting height of components mounted on the YMX board is allowed up to the dimension A shown in Figure 2, excluding the parts that intersect with the X board 4, and the allowable component height of the components themselves is the total height. Thickness is 10mm
In the case of a liquid crystal display device of about 300 ft, it has become possible to set it higher by about 3 m+++ compared to a liquid crystal display device of a conventional structure. Note that there is a space of 8 dimensions at the point where it intersects with the X board 4, and by mounting a component whose height is smaller than 8 dimensions, such as a resistor, at the point where it intersects with the X board 4, the conventional structure can be improved. It is possible to secure a mounting area equivalent to that of a liquid crystal display device. Next, the setting of the length of the X substrate will be explained using FIG. 3.

3(a) is an enlarged view of the circle in FIG. 1 with the metal frame 10 attached, and FIG. 3(b) is a side view thereof. In the present invention, by setting the C dimension to about D/2, the input terminal of the X board 4 and the flat cable 9 can be connected by soldering to external parts (for example, the light guide 7 of the backlight). This can be realized without any adverse effects due to heat, and by setting the 8 dimensions to about 1 mm, the X substrate 4 can be fixed by the metal frame 10 of the liquid crystal display device.

With the structure described above, it is possible to provide a liquid crystal display device with specifications equal to or higher than those of conventional thin liquid crystal display devices.

In this example, the case where two X boards are used is described, but
Needless to say, this can be achieved even with just one.

〔Effect of the invention〕

As described above, according to the present invention, the number of substrates can be reduced and low-cost components can be used, which has a tremendous effect on cost reduction of liquid crystal display devices. Furthermore, the number of assembly steps can be reduced due to the reduction in the number of substrates, and the number of defects in the backlight can also be reduced.

[Brief explanation of drawings]

FIG. 1(a) and FIG. 1(b) are diagrams showing a liquid crystal display device in an embodiment of the present invention. FIG. 2 is a diagram showing a - sectional view of FIG. 1(b). FIG. 4(a) and FIG. 4(b) are diagrams showing a conventional liquid crystal display device. FIG. 5(a) and FIG. 5(b) are views showing the - cross section of FIG. 4(b). Applicant Seiko Epson Co., Ltd. Agent Patent Attorney Kizobe Suzuki and 1 other person (b) (a) (a) No. 3
Figure C 4th garden

Claims (1)

[Claims] In a liquid crystal display device with a backlight that uses a flexible substrate on which an LSI for driving a liquid crystal panel is mounted, the input circuit board of the flexible substrate on which an LSI for driving a scanning electrode is mounted is a power supply circuit. The input circuit board of the flexible board on which the LSI for driving the signal electrode is mounted is three-dimensionally intersected with the input circuit board of the flexible board on which the LSI for driving the scanning electrode is mounted. A liquid crystal display device characterized by: