JPH06202137A - Liquid crystal device - Google Patents

Abstract

PURPOSE:To enable the lead coupling of TAB film resistant to temperature stress, impact, and vibration to be performed and to improve reliability for a liquid crystal device by connecting a liquid crystal driving substrate so as to be moved in the direction parallel with the panel surface. CONSTITUTION:A boss 3a with diameter smaller than that of a hole for substrate fixing provided at the liquid crystal driving substrate and a rib 3b to receive the liquid crystal driving substrate are provided at a part where the liquid crystal driving substrate of a panel fixing member 3 is fixed. Also, a screw 9 is screwed in the boss 3a in a shape to cover the hole for substrate fixing provided at the liquid crystal driving substrate. In such a case, it follows hat the liquid crystal driving substrate is connected so as to be moved by distance (x) for the fixing member 3 in the direction parallel with the plane of the panel 1, which prevents the liquid crystal driving substrate from being affected by the motion of the member 3 even when displacement between the panel 1 and the fixing member 3 occurs due to the change of environmental temperature and impact, and as a result, the lead destruction of the TAB film can be evaded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device using a ferroelectric liquid crystal, and more particularly to a method of mounting a liquid crystal drive substrate for supplying a drive signal to a panel.

[0002]

2. Description of the Related Art An example of a method of fixing a liquid crystal driving substrate to a panel fixing member in a conventional liquid crystal device will be described with reference to FIGS. In the figure, the panel 1 is adhesively fixed to the panel fixing member 3 via an adhesive such as a silicone rubber adhesive 4, and the liquid crystal drive substrate 2 is fixed to the panel fixing member 3 with screws 9 or the like.

Generally, in the panel 1, as shown in FIG. 7, a gap is provided between two glass substrates 1a and 1b having transparent electrodes, liquid crystal is sealed in the gaps, and a driving voltage is applied to the transparent electrodes. The liquid crystal is driven by. Further, a TAB-IC 5 for controlling drive signals and the like is mounted on the TAB film 6, and the liquid crystal drive substrate 2 and the panel 1 are called outer lead bonding (OLB) via the leads 7 of the TAB film 6 (flexible film). It is electrically connected by the method. Reference numeral 8 denotes a backlight that illuminates the panel from the back side, and the liquid crystal drive substrate 2 and the CPU substrate (not shown) that controls the entire liquid crystal device are flat cables 10.
Are electrically connected via.

[0004]

However, since the liquid crystal driving substrate 2 is integrally fixed to the panel fixing member 3 in the above conventional example, the liquid crystal driving substrate 2 is positioned between the panel 1 and the panel fixing member 3 by a mechanical external force or the like. When the slippage occurs, stress may be directly applied to the joint portion of the lead 7 of the TAB film 6, which may cause a defect such as breakage of the lead 7 of the TAB film 6.

FIG. 8 is an enlarged view of a joint portion of the TAB film 6, the panel 1 and the liquid crystal drive substrate 2. The pitch of the joint between the lead 7a of the TAB film 6 and the liquid crystal drive substrate 2 is usually 0.3 to 1 mm, and the pitch of the joint between the lead 7b of the TAB film 6 and the panel 1 is as narrow as 0.1 to 0.3 mm. In such a structure, the leads 7b of the TAB film 6 are particularly thin, so that they easily break with a small force.

Further, the material of the panel 1 is usually glass and the material of the panel fixing member 3 is often a plastic member, and there is a marked difference in the coefficient of thermal expansion between them.
For example, in FIG. 7, when the environmental temperature changes, the panel fixing member 3
Even if is stretched due to thermal influence, the panel 1 has a coefficient of thermal expansion significantly different from that of the panel fixing member 3, so that there is almost no extension, and the panel fixing member 3 moves in the direction of arrow A in the figure, and The position is equivalent to not moving. Since the liquid crystal drive substrate 2 is integrally fixed to the panel fixing member 3 with a screw, it moves with the extension of the panel fixing member 3. That is, the mechanical stress due to the difference between the moving liquid crystal drive substrate 2 and the non-moving panel 1 is concentrated on the mechanically weak portion of the lead 7 of the TAB film 6. In particular, with the recent trend toward larger liquid crystal devices, the above-mentioned fixing method also causes a situation in which dimensional changes due to differences in elongation due to environmental temperature changes cannot be coped with remarkably.

Therefore, the present invention provides a liquid crystal device in which damage to the leads is prevented by reducing the stress generated in the leads even if the panel and the panel fixing member are misaligned due to a difference in thermal expansion coefficient or the like. To aim for things.

[0008]

The present invention has been made in view of the circumstances, and a panel and a liquid crystal drive substrate for supplying a drive signal to the panel are connected by a liquid crystal drive TAB-IC. In a liquid crystal device in which a liquid crystal driving substrate is screwed and integrated with a supporting member of the panel, the supporting member has a boss portion slightly higher than the thickness of the liquid crystal driving substrate, and the liquid crystal driving substrate Has a fixing hole that is loosely fitted to the boss portion with a predetermined gap, and by screwing the liquid crystal drive substrate to the support member with the screw, the liquid crystal drive substrate can be moved by the predetermined gap. It is characterized by that.

[0009]

According to the above structure, the support member is provided with the boss portion slightly higher than the thickness of the liquid crystal drive substrate, and the liquid crystal drive substrate is provided with the fixing hole which is fitted with the boss portion with a predetermined gap. The liquid crystal driving substrate is movable by a predetermined gap.
Also, by providing a regulation means for regulating the tightening force of the screw,
The liquid crystal drive substrate and the support member are fixed without being fixed, and the liquid crystal drive substrate can be moved when a force is applied to the liquid crystal drive substrate.

[0010]

Embodiments of the present invention will be described with reference to the drawings. Figure 1
2 is a perspective view of the liquid crystal device, and FIG. 2 is a cross-sectional view showing a screwed portion of the panel. In the figure, 1 is a panel, 2
Is a liquid crystal drive substrate, 3 is a panel fixing member, 4 is a silicon adhesive, 5 is a TAB-IC, 6 is a TAB film 6, 7 is a lead of the TAB film 6, 8 is a backlight, 9 is a screw, 10 is a flat cable. Is.

In the above structure, the portion of the panel fixing member 3 for fixing the liquid crystal driving substrate 2 has a boss 3a having a diameter smaller than the diameter of the hole for fixing the substrate provided in the liquid crystal driving substrate 2.
Leave 3b for receiving the (boss portion) and the liquid crystal drive substrate 2
Is provided. Further, the screw 9 is screwed into the boss 3a so as to cover the substrate fixing hole provided in the liquid crystal drive substrate 2.

FIG. 3 is an exploded perspective view showing the liquid crystal drive substrate 2, the panel fixing member 3 and the screw 9 in the portion shown in FIG. In the figure, the lower surface of the liquid crystal drive substrate 2 rides on the ribs 3 b of the panel fixing member 3 and is fixed with screws 9. At this time, the height h from the upper surface of the rib 3b to the boss 3a is slightly larger than the thickness t of the liquid crystal drive substrate 2 by about 0.1 to 0.2 mm. Now, if the liquid crystal drive substrate 2 is sandwiched between the screw 9 and the panel fixing member 3 and the screw 9 is tightened, there is a relationship of t <h. Therefore, the screw 9 stops on the upper surface of the boss 3a and the liquid crystal drive substrate 2 is fixed. It is possible to regulate the vertical direction with a little play without tightening.

Further, when the diameter of the substrate fixing hole 2a of the liquid crystal driving substrate 2 is D and the diameter of the boss 3a is d, the substrate fixing hole 2 is formed.
When a (fixing hole) and the center of the boss 3a are aligned with each other, a (D−d) / 2 gap is formed between the boss 3a and the substrate fixing hole 2a. If this gap is defined as x, the liquid crystal drive substrate 2 is locked so as to be movable in the direction parallel to the surface of the panel 1 by the distance x with respect to the panel fixing member 3, so that the liquid crystal drive substrate 2 receives a change in environmental temperature or an impact. Even if a positional deviation y occurs between the panel 1 and the panel fixing member 3 when the liquid crystal is driven, if the value of the deviation amount y is in the range of xy> 0, the liquid crystal drive is driven by the movement of the panel fixing member 3. The substrate 2 is not affected, and as a result, lead breakage of the TAB film 6 can be avoided. In our experiment, the size of the panel 1 is 300 mm and the size of the panel fixing member 3 is 370 on one side of the liquid crystal device.
mm, when the ambient temperature changes from 25 ℃ to 60 ℃ T
Lead breakage of the AB film 6 occurred. At this time, the difference in elongation between the panel 1 and the panel fixing member 3 was about 0.6 mm, but if the elongation appears evenly at both ends, the positional deviation y between the panel 1 and the panel fixing member 3 is 1 Since it is / 2, the result is that it should be set so that x> 0.3 in the above dimension and temperature range.

Therefore, based on this result, the value of x can be calculated by calculation even when the panel fixing member 3 having a different thermal expansion coefficient is used or the size is different, and the present invention can be easily applied. It is possible to

In this embodiment, the contact between the liquid crystal drive substrate 2 and the panel fixing member 3 is in contact with the rib 3b in order to make the liquid crystal drive substrate 2 easily movable. 2 lower surface and panel fixing member 3 upper surface 3
Almost the same effect can be obtained even if c is in contact. <Other Embodiments> (1) In the embodiment, the panel fixing member 3 is provided with the boss 3a to movably lock the liquid crystal drive substrate 2, but the screw 9 is stepped (regulating means) as shown in FIG. If the diameters d'and H'of the stepped portion of the screw are made the same as the diameters and heights of the boss 3a d'and H ', the same effect can be obtained even if the boss 3a is eliminated. Is. (2) In the embodiment, the panel fixing member 3 is provided with the boss 3a to movably lock the liquid crystal drive substrate 2, but as shown in FIG. 5, the insert metal 11 (regulating means) is used instead of the boss 3a for the panel. It is also possible to substitute the embedded boss 3a in the fixing member 3 and to obtain the same effect as in the embodiment, which has a higher screw attachment / detachment durability than the case where the screw 9 is directly screwed into the panel fixing member 3 which is a plastic part. Is possible. (3) In the embodiments described so far, the pressing from the top of the liquid crystal drive substrate 2 is performed by the diameter of the head of the screw 9. However, when the movement amount x is set to a large value, it is difficult to machine the screw head. In this case, the same effect can be obtained by disposing the washer 12 between the liquid crystal drive substrate 2 and the head of the screw 9 as shown in FIG.

[0016]

As described above, according to the present invention, the liquid crystal drive substrate is not fixed integrally with the panel fixing member but is locked so as to be movable in the direction parallel to the surface of the panel. The TAB film, which is resistant to stress, shock and vibration, can be lead-bonded, which has the effect of improving the reliability of the liquid crystal device.

[Brief description of drawings]

FIG. 1 is a top view of a liquid crystal device applied to the description of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a liquid crystal drive substrate mounting portion applied to the description of an embodiment of the present invention.

FIG. 3 is an assembly diagram of a liquid crystal drive substrate mounting portion applied to the description of the embodiment of the present invention.

FIG. 4 is a cross-sectional view of a liquid crystal drive substrate mounting portion applied to the description of another embodiment of the present invention.

FIG. 5 is a cross-sectional view of a liquid crystal drive substrate mounting portion applied to the description of another embodiment of the present invention.

FIG. 6 is a cross-sectional view of a liquid crystal drive substrate mounting portion applied to the description of another embodiment of the present invention.

FIG. 7 is a cross-sectional view of a liquid crystal drive substrate mounting portion applied to the description of the conventional technique.

FIG. 8 is a top view of a liquid crystal drive substrate mounting portion applied to the description of the conventional technique.

[Explanation of symbols]

 1 panel 2 liquid crystal drive substrate 2a substrate fixing hole (fixing hole) 3 panel fixing member (supporting member) 3a boss (boss portion) 6 flexible film 9 screw 11 insert metal (regulating means)

Front Page Continuation (72) Inventor Nao Tajima 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Kenji Shinbori 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Hiroshi Takabayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (1)

[Claims] 1. A liquid crystal panel and a liquid crystal driving substrate for supplying a driving signal to the liquid crystal panel are connected by a liquid crystal driving TAB-IC, and the liquid crystal driving substrate is screwed to a supporting member of the liquid crystal panel with a screw. In the integrated liquid crystal device, the support member has a boss portion slightly higher than the thickness of the liquid crystal drive substrate, and the liquid crystal drive substrate has a fixing hole for loosely engaging the boss portion with a predetermined gap. A liquid crystal device, wherein the liquid crystal drive substrate is movable by the predetermined gap by screwing the liquid crystal drive substrate to the support member with the screw.