JPH05142562A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To shorten the width of a power source circuit substrate. CONSTITUTION:As to the liquid crystal display device constituted of a liquid crystal display substrate, a power source circuit substrate 22 arranged so as to be positioned around the liquid crystal display substrate and a liquid crystal display driving circuit substrate 23 positioned between the liquid crystal display substrate and the power source circuit substrate 22 and arranged so as to be provided with the group of electrodes respectively connected with the group of electrodes on each substrate surface, a capacitor 8 for absorbing a noise out of the power source circuit mounted on the power source circuit substrate 22 is mounted on the liquid crystal display driving circuit substrate 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device,
In particular, the present invention relates to a liquid crystal display device in which a liquid crystal display board, a liquid crystal display drive circuit board for driving the liquid crystal display board, and a power supply circuit board for driving the liquid crystal display drive circuit board are modularized.

[0002]

2. Description of the Related Art A liquid crystal display substrate having such a structure is conventionally structured as shown below.

That is, there is a liquid crystal display board, and a power supply circuit board formed by mounting a power supply circuit on a printed board, for example, is positioned around the liquid crystal display board. A liquid crystal display drive circuit board is arranged between the power supply circuit board and the liquid crystal display board.

In this liquid crystal display drive circuit board, a liquid crystal display drive LSI is mounted on a film-like flexible board, and the input terminals and output terminals of this LSI are drawn out as electrode groups through a wiring layer. ing. The flexible substrate is used to facilitate manufacturing.

The liquid crystal display drive circuit board is composed of a plurality of electrodes, the electrode groups corresponding to the input terminals are connected to the electrode groups on the surface of the power supply circuit board, and the electrode groups corresponding to the output terminals are the liquid crystal display. It is arranged so as to be connected to the electrode group on the substrate surface (Japanese Utility Model Publication No. 1-23164).

[0006]

In the liquid crystal display device having such a structure, in recent years, the width of the power supply circuit board, that is, the length of the power supply circuit board matched in the direction orthogonal to the periphery of the liquid crystal display board. There is a growing tendency to reduce

This is because when the liquid crystal display device is incorporated in a panel, the width of the edge portion (usually called a frame) around the liquid crystal display substrate becomes small, which is aesthetically very good.

However, it goes without saying that all the electronic components of the power supply circuit mounted on the power supply circuit board are required, and the arrangement of them is so space-saving. Therefore, it has been extremely difficult to make the width of the power supply circuit board smaller than ever.

Therefore, the present invention has been made under such circumstances, and an object thereof is to provide a liquid crystal display device capable of reducing the width of a power supply circuit board. It is in.

[0010]

In order to achieve such an object, the present invention basically comprises a liquid crystal display substrate and a power supply circuit substrate positioned around the liquid crystal display substrate. A liquid crystal display device including a liquid crystal display drive circuit board positioned between the liquid crystal display board and a power supply circuit board, the liquid crystal display drive circuit board being provided with an electrode group connected to an electrode group on each board surface. In the power supply circuit mounted on the substrate, a capacitor for absorbing noise is mounted on the liquid crystal display drive circuit substrate.

[0011]

The liquid crystal display device constructed as described above is
In the power supply circuit mounted on the power supply circuit board, a capacitor for absorbing noise is mounted on the liquid crystal display drive circuit board.

Such a capacitor has, for example, a width of 1.
It consists of 0 mm to 1.5 mm, length 4 mm, and height 1.5 mm, and is arranged on the power supply circuit board in an amount corresponding to the number of liquid crystal display drive circuit boards (for example, about 15). is there. Therefore, the area occupied by the capacitors in the power supply circuit board has a large ratio.

On the other hand, in the liquid crystal display drive circuit board, only the liquid crystal display drive LSI is mounted and only the wiring layer is formed. For example, about one of the capacitors is sufficiently mounted. It has something to do.

Therefore, since the above-mentioned capacitor is not mounted on the power supply circuit board, the area occupied by other electronic components on the power supply circuit board can be reduced. Therefore, the width of the power supply circuit board can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a schematic development block diagram showing an embodiment of a liquid crystal display device according to the present invention.

In FIG. 1, first, there is a liquid crystal display substrate 21. As is well known, the liquid crystal display substrate 21 is made of a glass substrate having a liquid crystal layer sandwiched between the liquid crystal display substrate 21 and an electrode group formed around the glass substrate.

A power supply circuit board 22 having a power supply circuit mounted on a printed circuit board is positioned around the liquid crystal display board 21.

A liquid crystal display drive circuit board 23 is arranged between the power supply circuit board 22 and the liquid crystal display board 21. In this liquid crystal display drive circuit board 23, a liquid crystal display drive LSI is mounted on a film-shaped flexible board, and the input terminals and output terminals of this LSI are drawn out as electrode groups via wiring layers. .. The flexible substrate is used for the purpose of facilitating the manufacture by adopting the so-called tape carrier method.
It is called AB.

The liquid crystal display drive circuit board 23
Is composed of a plurality of electrodes, the electrode group corresponding to the input terminal thereof is connected to the electrode group on the surface of the power circuit board 22, and the electrode group corresponding to the output terminal is connected to the electrode group on the surface of the liquid crystal display substrate 21. It has been arranged.

The structure of the liquid crystal display drive circuit board 23 will be described in detail again with reference to FIG.

Further, a light guide plate 25 is arranged on the back side of the liquid crystal display substrate 21 via a diffusion plate 24, and a cold cathode fluorescent tube 26 is provided on a pair of side end faces of the light guide plate 25. It is arranged. That is, the cold cathode fluorescent tube 26
Light is guided into the light guide plate 25 through the side end face, diffused and emitted from the main surface side through the diffusion plate 24, and illuminates the back surface of the liquid crystal display substrate 21.

A spacer 27 is arranged between the liquid crystal display substrate 21 and the diffusion plate 24, and a resin case 28 for arranging the light guide plate 25 and the cold cathode fluorescent tube 2 is also provided. A reflection plate 29 is arranged on the back surface of the light guide plate 25.

A frame 31 is arranged in front of the liquid crystal display substrate 21 via a spacer 30, and the frame 31 is caulked to the reflection plate 29 to fix the above-mentioned members.

Next, FIG. 1 is a perspective view showing the details of the liquid crystal display drive circuit board 23.

In FIG. 1, first, there is a liquid crystal display drive circuit board 23. The liquid crystal display drive circuit board 23 is a circuit board formed by a so-called tape carrier method.
The insulating substrate is a film-shaped resin substrate. A liquid crystal display driving LSI 2 is so-called face-down bonded on the upper surface of the film-shaped resin substrate 1. The electrodes (not shown) of the liquid crystal display driving LSI 2 are taken out to the respective leads via the wiring layer 3 formed on the back surface of the film-shaped resin substrate 1.

Of these leads, the lead on the side of the power supply circuit board 22 is referred to as the outer lead 4, and is formed so as to extend from the end side of the film-shaped resin substrate 1 so as to project.

On the other hand, the power supply circuit board 22 is formed with an electrode group consisting of the respective electrodes 5 so as to be connected to the outer leads 4 of the liquid crystal display drive circuit board 23. A solder resist film 6 is deposited on the power supply circuit board 22 so as to expose the electrode group as a unit and cover the other area (wiring layer formation area).

Of the leads, the lead on the liquid crystal display substrate 21 side is called the inner lead 7, and is formed by being attached to the edge of the film-like resin substrate 1.

The inner leads 7 are used for the liquid crystal display substrate 2
It is connected to the electrode group on one surface, and is connected via, for example, an anisotropic conductive film (not shown).

Further, in this embodiment, in addition to the liquid crystal display driving LSI 2, the capacitor 8 is mounted on the film-shaped resin substrate 1. Each electrode of the capacitor 8 is led out to the outer lead 4 via the wiring layer 3 and connected to a predetermined portion of the power circuit on the power circuit board 22.

Next, FIG. 3 is a circuit diagram showing the connection points of the capacitors in the relationship between the power supply circuit and the liquid crystal display drive circuit. That is, the capacitors 8 (C1 to C1) are provided only at the connection portions between the power supply circuit 22A on the power supply circuit board 22 and the respective liquid crystal display drive circuit boards 22.
4) is connected. In this case, the number of the capacitors 8 is almost the same as the number of the liquid crystal display drive circuits 23, and by mounting one capacitor 8 for each liquid crystal display drive circuit 23, the power source circuit board 22 is provided with the capacitors 8 at all. It will not have to be installed.

The capacitors C1 to C14 do not necessarily have to be mounted on the power supply circuit board 22 side due to the connection form, and can be mounted on the liquid crystal display drive circuit board 23 side. And, this does not cause the wiring to be complicated.

As described above, particularly in the above-described embodiment, the liquid crystal display drive circuit board 23 includes the capacitor 8 for absorbing noise in the power supply circuit mounted on the power supply circuit board 22.
It is designed to be mounted on top.

Such a capacitor 8 has, for example, a width of 1.0 mm to 1.5 mm, a length of 4 mm and a height of 1.5 mm.
The liquid crystal display drive circuit boards 23 are arranged on the power supply circuit board 22 in an amount corresponding to the number (for example, about 15) of the liquid crystal display drive circuit boards 23. Therefore, the area occupied by the capacitor 8 on the power supply circuit board 22 has a large ratio.

On the other hand, the liquid crystal display drive circuit board 23
In, only the liquid crystal display drive LSI 2 is mounted,
Further, only the wiring layer 3 is formed, and for example, one or more of the capacitors 8 have a sufficient margin for mounting.

For this reason, since the above-mentioned capacitor 8 is not mounted on the power supply circuit board 22, the area occupied by other electronic components on the power supply circuit board 22 can be made small. Therefore, the width of the power supply circuit board 22 can be reduced.

In the above-mentioned embodiments, one liquid crystal display drive circuit board is provided with one capacitor, but the present invention is not limited to this, and two or three capacitors are provided. Of course, you can.

[0038]

As is clear from the above description,
According to the liquid crystal display device of the present invention, the width of the power supply circuit board can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective configuration diagram showing an embodiment of a liquid crystal display drive circuit board in a liquid crystal display device according to the present invention.

FIG. 2 is a schematic perspective view showing an embodiment of a liquid crystal display device according to the present invention.

FIG. 3 is a circuit diagram showing connection points of capacitors for absorbing noise in a power supply circuit and a liquid crystal display drive circuit.

[Explanation of symbols]

1 ... Film-shaped resin substrate, 2 ... LSI for driving liquid crystal display,
3 ... Wiring layer, 4 ... Outer lead, 7 ... Inner lead, 8 ... Capacitor, 21 ... Liquid crystal display board, 22 ... Power supply circuit board, 23 ... Liquid crystal display drive circuit board.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takao Higashi 3300 Hayano, Mobara-shi, Chiba Hitachi Ltd. Mobara factory

Claims (1)

[Claims] 1. A liquid crystal display substrate, a power supply circuit substrate positioned around the liquid crystal display substrate, and an electrode group on each substrate surface positioned between the liquid crystal display substrate and the power supply circuit substrate. In a liquid crystal display device comprising a liquid crystal display drive circuit board arranged with an electrode group connected thereto, a capacitor for absorbing noise in a power supply circuit mounted on the power supply circuit board is the liquid crystal display drive circuit board. A liquid crystal display device characterized by being mounted on top.