JP2948466B2 - Liquid crystal display device - Google Patents

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.
More specifically, the signal processing provided in the middle of the flexible film foil lead wire due to static electricity generated in the flexible film having the foil lead wire connected to the liquid crystal display panel or the electrode terminal of the liquid crystal display panel. The present invention relates to a liquid crystal display element in which a use IC is protected.

[0002]

2. Description of the Related Art An electrode of each pixel of a liquid crystal display element is led to one end of a liquid crystal display panel and connected to a terminal of a circuit board on which a drive circuit is formed. The liquid crystal display panel and the circuit board need to be provided in a narrow place due to the demand for miniaturization of electronic equipment, and the circuit board is provided on the back side of the liquid crystal display panel and connected between the liquid crystal display panel and the circuit board. The lead wire to be formed needs to be bent. Therefore, a flexible film having thin foil-like lead wires, T
AB and FPC are used. Here, TAB refers to one having a signal processing IC in the middle of the foil-shaped lead wire among those having a large number of foil-shaped lead wires and having flexibility held by an electrically insulating flexible film. The FPC has no IC, and has only a foil-like lead wire held by a flexible film.

When the number of electrode terminals provided at the end of the liquid crystal display panel is very large, for example, when the number of lead wires to be connected is as large as about 30 per cm, for example, connection is made without short-circuiting to a circuit board. Since it is difficult to do so, a TAB that reduces the number of lead wires by inserting a signal processing IC in the middle of the wiring is first connected to the liquid crystal display panel, and then connected to the circuit board via the FPC. ing. FIG. 4 is an exploded explanatory view of the same.

In FIG. 4, reference numeral 41 denotes a liquid crystal display panel;
AB and 50 are FPCs. In the liquid crystal display panel 41, the electrode terminals for each pixel are led to one end C of one transparent substrate (not shown) and connected to one end (not shown) of the foil lead wire of the TAB 42. Has become.

[0005] TAB 42 is a flexible film 43 in which a foil-like lead wire (not shown but on the back side of the figure) is provided. An IC 44 is provided in the middle of the foil-like lead wire. Are provided with positioning guide holes 46, 47 for aligning and connecting the other end 45 of the FPC 50 to one end 51 of the foil lead wire of the FPC 50. The FPC 50 is connected to the TAB 42 at one end 51 of a foil lead wire (not shown) provided on the flexible film 55, and the other end 52 is connected to the set-side circuit board. In addition, TAB42
Guide portions 53 and 54, which are designated as positioning guide holes 46 and 47 of the TAB 42, are provided so that the respective lead wire terminals of the FPC 50 and the FPC 50 can be accurately positioned. That is, the conventional TAB 42 or FPC 50 is provided with a foil-like lead wire on one surface side of the flexible films 43 and 55, and a cover film is provided thereon to prevent the flexibility from being hindered. Therefore, no shielding foil or the like is attached.

[0006]

As described above, the conventional liquid crystal display element mainly comprises an electrically insulating substrate made of a glass plate or the like constituting a liquid crystal display panel and a flexible organic film made of polyimide or the like. And is easily charged with static electricity. In the past, liquid crystal display panels were often mounted on a metal chassis on the set side with metal bands, etc., and static electricity generated on the liquid crystal display panel etc. was discharged when mounting to the set, and there was no particular problem,
With the recent plasticization of electronic devices, static discharge is unlikely to occur even when mounted on a set. Therefore, the accumulated static electricity is provided in the TAB IC
Has a problem of destroying it.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a liquid crystal display element which releases static electricity even if static electricity is generated on a liquid crystal display panel or the like and does not damage the IC. And

[0008]

According to the present invention, there is provided a liquid crystal display element comprising: (a) a liquid crystal display panel having a liquid crystal layer sandwiched therein and provided with respective electrode terminals; and (b) a liquid crystal display panel provided with the electrode terminals. A first flexible film having a foil-like lead wire to which one end is connected and to which an IC is connected in the middle, and a portion of the first flexible film adjacent to the IC. Or
In addition, a grounding pattern is provided at a portion where the foil-like lead wire is not provided.

[0009] The ground pattern is provided on the periphery of the IC.
When it is provided around the positioning guide hole provided,
In further comprising a second flexible film with foil leads that may be connected to between the terminal part of the other end portion and the circuit board foil lead of the first flexible film, The fact that the second flexible film is provided with a ground wire that is connected to the ground pattern and that can be connected to a ground terminal of the circuit board is that the distance between the liquid crystal display panel and the circuit board is long. In such a case, it is preferable because static electricity can be reliably discharged to protect the IC.

[0010]

According to the present invention, a ground pattern is provided around a TAB IC, and the ground pattern is connected to a ground terminal provided on an FPC connected to the TAB or directly to a ground terminal provided on a circuit board. Statically, static electricity generated on the liquid crystal display panel or the flexible film can be easily discharged via the ground pattern. As a result, the IC mounted on the TAB is not destroyed.

Further, since the grounding pattern is provided on the periphery of the IC which covers the gap between the foil-like lead wires, for example, around the positioning guide hole, the lead wire is independent of the bent portion of the foil-like lead wire. And no adverse effect on the bending of the flexible film.

[0012]

Next, the liquid crystal display device of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a main part of an embodiment of the liquid crystal display element of the present invention, FIG. 2 is an enlarged view of a ground pattern part of TAB, and FIG. 3 is a view showing a state where the main part of FIG. It is.

In FIG. 1, a liquid crystal display panel 1 is the same as a conventional liquid crystal display panel. A liquid crystal layer is sandwiched between two transparent substrates 11 and 12 on which an electrode pattern and the like are formed. Of the transparent substrate 11 (not shown).

The TAB 2 has a foil-like lead wire (not shown) provided on the back side of a first flexible film 21 of polyester, polyimide or the like, and an IC 23 provided in the middle thereof. The foil lead wire is further provided with a cover film except for a terminal portion and a particularly bendable portion to be protected. One end (not shown) of each of the foil leads is aligned so as to be connected to an electrode terminal of the liquid crystal display panel 1 by an anisotropic conductive adhesive or the like, and the other end of each of the foil leads is provided. The part 22 is connected to one end of each of the foil lead wires of the FPC 3 by soldering or the like. There are a large number of electrode terminals of the liquid crystal display panel 1 at a pitch of, for example, about 0.3 mm, and one end of the foil-like lead wire provided on the TAB 2 has a corresponding number. Connected to the other end of the foil lead
22 is the number that can be connected to the circuit board. Positioning guide holes 24 and 25 are provided on both sides of the IC 23 for positioning the other end 22 of the foil lead wire with a terminal such as the FPC 3. These positioning guide holes 24 and 25 are IC
The reason why it is provided beside the IC 23 is that lead wires are attached to the upper and lower sides of the IC 23, but there is a space without wiring next to the IC 23. The present invention is characterized in that a ground pattern 26 is provided on the periphery of the IC 23 of the TAB 2, for example, around the positioning guide holes 24 and 25. The ground pattern 26 is electrically connected to the ground wiring of the FPC 3 when the TAB 2 and the FPC 3 are connected.

As described above, the positioning guide holes 24 and 25 are provided in portions where there is no foil-like lead wire, and the grounding pattern 26 is provided next to the IC because the TAB 2 is not bent. However, the function as TAB2 is not impaired at all. On the other hand, the earth pattern 26 is IC23
, The liquid crystal display panel 1 and the first
When the static electricity generated on the flexible film 21 attempts to discharge to the IC 23 side, it flows into the ground pattern 26 connected to the ground line and does not discharge to the IC 23. Therefore, the IC 23 which is easily broken by static electricity can be effectively protected.

The FPC 3 is a group of bendable leads in which a foil-like lead (not shown) and a cover film are provided on a second flexible film 31 like the TAB 2. One end 32 is electrically connected to the other end 22 of the TAB2 foil lead wire by soldering or the like, and the other end 33 is connected to a set of circuit terminals such as a circuit board.

The FPC 3 of this embodiment is provided with a ground wire 36 passing through positioning portions 34, 35 corresponding to the positioning guide holes 24, 25 of the TAB 2, and one end of the ground wire is connected to the other end 33 of the foil lead wire. It is characterized in that it is provided as a ground terminal 37 at the same place and is connected to the ground wire of the set. The flexible film is bonded to the TAB 2 and the FPC 3 at the positioning guide holes so that the ends of the foil lead wires are electrically connected to each other by solder or the like and maintain mechanical strength. Therefore, by performing this bonding using a conductive adhesive or soldering, the ground pattern 26 of the TAB 2 and the ground wiring 36 of the FPC 3 are electrically connected, and the first flexible film 21 is formed.
Static electricity generated in the set can be released to the ground wire on the set side.

In the above embodiment, the connection between the other end 22 of the foil-like lead wire of the TAB 2 and the circuit board on the set side via the FPC 3 has been described. However, due to the space on the set side, the TAB 2 If it is possible to directly connect the TAB 2 to the circuit board,
Provide a ground wire on the circuit board portion aligned with 4, 25, or provide a ground wire connected to the ground pattern of TAB2 on TAB2 and connect it to the ground wire together with the other end 22 of the foil lead wire. Terminals may be provided.

[0019]

According to the present invention, a TAB provided with an IC is provided.
A ground pattern is provided around the IC and connected to the ground wire on the set side, so that the static electricity generated on the liquid crystal display panel and the flexible film is discharged to the ground and the IC is destroyed. Is prevented. As a result, the IC does not break down when the liquid crystal display element is assembled or used, and the reliability is greatly improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a main part of one embodiment of a liquid crystal display device of the present invention.

FIG. 2 is an enlarged explanatory view of a ground pattern portion provided in the TAB of FIG. 1;

FIG. 3 is a diagram showing a state in which the members of FIG. 1 are connected.

FIG. 4 is an exploded perspective view of a main part of a conventional liquid crystal display element.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 liquid crystal display panel 2 TAB 3 FPC 21 first flexible film 23 IC 26 ground pattern 31 second flexible film 36 ground wiring

Claims (2)

(57) [Claims] (A) a liquid crystal display panel in which a liquid crystal layer is sandwiched and electrode terminals are provided; and (b) one end is connected to the electrode terminals of the liquid crystal display panel, and an IC is provided in the middle. A first flexible film having a connected foil-like lead wire, at least in a portion of the first flexible film adjacent to the IC .
First, a liquid crystal display element in which a grounding pattern is provided on a portion without the foil-like lead wire . 2. The method according to claim 1, wherein the ground pattern is a periphery of the IC.
When it is provided around the positioning guide hole provided in
Both further include a second flexible film having a foil-like lead wire that can be connected between the other end of the foil-like lead wire of the first flexible film and the terminal portion of the circuit board, 2. The liquid crystal display element according to claim 1, wherein said second flexible film is provided with a ground wiring which is connected to said ground pattern and can be connected to a ground terminal of said circuit board.