JPH03121417A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To allow the fixing and holding of a liquid crystal panel in a flat state without deforming the panel and to prevent the generation of disconnection by the deformation of liquid crystal substrates by providing the liquid crystal display panel which is formed by using polymer film substrates and rubber members on the front and rear surfaces of a heat sealing pat of a flexible connector and further compressing the rubber members. CONSTITUTION:The liquid crystal display panel 1 formed by using the polymer film substrates, a driving circuit substrate 6, and the flexible connector 4 which is connected at one end to the liquid crystal display panel 1 and at the other end to the driving circuit substrate 6, respectively, are pinched and fixed by a supporting frame body 7. The fixing is executed by providing the rubber members 5 on the front and rear surfaces of the heat sealing part of the liquid crystal display panel 1 and caulking a pawl-shaped body 8 provided on the supporting frame body 7 on the rear surface of the driving circuit substrate 6, thereby compressing the rubber members 5 with the supporting frame body 7. The liquid crystal display panel 1 formed by using the polymer film substrates is fixed and held in this way without deforming the panel. The connection of the liquid crystal display panel 1 and the driving circuit substrate 6 is thus assured with high reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a liquid crystal display device having a liquid crystal display panel using a polymer film substrate, and particularly to a method for fixing a liquid crystal display panel.

[Prior Art and Problems to be Solved by the Invention] In a liquid crystal display device, the lead electrodes of the liquid crystal panel and the drive circuit board are generally connected using a zebra connector or by a heat sealing method. Depending on the connection form, a structure for fixing and holding the liquid crystal display panel is required.

When using a zebra connector, it is necessary to compress the zebra connector by a certain amount in order to establish continuity between the lead electrodes of the liquid crystal display panel and the electrodes on the drive circuit board. This is done by caulking the metal support frame 24 and the drive circuit board 23 with claw-like bodies 25 provided on the support frame 24. Various forms of the claw-like bodies 25 can be considered. However, no special structure is required to securely hold the liquid crystal display panel 21.

Furthermore, in liquid crystal display devices using polymer film substrates, heat sealing is more often used than zebra connectors to connect the liquid crystal display panel and drive circuit board. Conventionally,
In the case of connection by the heat seal method, for example, the segment electrode 34 is connected to the heat seal connector 3 as shown in FIG.
It is common to connect directly to the drive circuit board 35 through the wire 6. In this case, the common electrode on the lower substrate 33 and the drive circuit board 35 are connected via a film connector (not shown) such as an FPC.
Since the segment portions are directly connected to the drive circuit board 35, a special structure for fixing the liquid crystal display panel 31 is not required.

On the other hand, in recent years, PE with a thickness of about 100 mm has been used as a substrate in order to make liquid crystal display devices thinner, lighter, and more impact resistant.
The use of polymer film substrates such as T, PES, and PC is attracting attention. A transparent conductive film is formed on one side of a polymer film substrate by vapor deposition or sputtering, but the peritoneal conditions are limited to some extent because the film material itself that serves as the substrate has lower thermal properties than glass. Therefore, the degree of adhesion of the formed film and the mechanical strength of the inner film are inferior to those formed on glass. Furthermore, since the substrate itself is flexible, external stresses such as excessive bending, twisting, and pulling can easily cause film peeling and cracking. Therefore, the connection form and fixation must be designed so that no stress is applied to the LCD panel itself. A method is needed. The influence of external stress on the film becomes greater as the electrode pitch becomes finer as the display capacity becomes higher and the size of the liquid crystal display panel becomes larger.

Although the connection form shown in FIG. 5 does not require any special means for fixing the liquid crystal display panel 31, there is a risk of damage to the film because the structure bends the substrate near the heat-sealed part. If a large EL backlight or the like is inserted between the liquid crystal display panel 31 and the drive circuit board 35, the difference in height between the heat-sealed part and the display part will be large, which will increase the bending rate and prevent damage to the film. The risks are even greater. In order to reduce the bending ratio near the electrode lead portion, it is necessary to increase the length of the electrode lead portion. On the other hand, in this connection form, since the heat from the heat seal connection is applied from the film substrate side during heat seal connection, there is a large risk of thermal damage to the transparent electrode.

In order to minimize external stress on the liquid crystal display panel, a film connector 44 having a rigidity equal to or less than that of the polymer film substrate is heated to both the segment and common electrode leads, as shown in FIG. A conceivable method is to connect the film connectors 44 with a seal and heat seal the other ends of the film connectors 44 to the drive circuit board 45. However, in a configuration connected by this method, the liquid crystal display panel 41 is suspended in the air as shown in the figure.
When modularizing, it becomes necessary to securely hold the liquid crystal display panel 41.

The present invention has been made in view of the actual state of the prior art, and is capable of fixing and holding a liquid crystal display panel using a polymer film substrate without causing deformation, and is capable of fixing the liquid crystal display panel and the drive circuit board. An object of the present invention is to provide a liquid crystal display device whose connection is guaranteed with high reliability.

[Means to solve the problem]

In order to achieve the above object, the invention according to claim 1 provides a liquid crystal display panel using a polymer film substrate, a drive circuit board, one end of which is attached to the liquid crystal display panel, and the other end of which is attached to the drive circuit board using a heat sealing method. In a liquid crystal display device in which a flexible connector to be connected by is sandwiched and fixed between support frames, the fixing is provided on the support frame by providing rubber members on the upper and lower surfaces of the heat seal part of the liquid crystal display panel. The rubber member is compressed between the support frame and the support frame by caulking the claw-like member onto the lower surface of the drive circuit board.

In the invention according to claim 2, in the above configuration.

A notch was formed at the bending position of the claw-like body.

According to a third aspect of the present invention, in the above structure, a stopper that comes into contact with the upper surface of the drive circuit board is provided on the support frame.

[Effect]

According to the invention set forth in claim 1, the liquid crystal display panel is fixedly held by compressing the rubber members provided on the upper and lower surfaces of the heat-sealed portion of the liquid crystal display panel, so that no stress that causes deformation is applied to the liquid crystal display panel. The LCD panel can be held flat, and there is no need to worry about wire breakage, improving connection reliability.

According to the invention as claimed in claim 2, in addition to the above-mentioned effect, since the notch is formed at the bending position of the claw-like body, the bending position is regulated and the compression ratio of the rubber member can be maintained at the set value, and the rubber member can be fixed. Holding can be performed more stably.

Further, according to the invention as claimed in claim 3, in addition to the above-mentioned effect, since the support frame is provided with a stopper that comes into contact with the upper surface of the drive circuit board, the compression ratio of the rubber member can be maintained at a set value, and the rubber member can be held fixed. can be performed more stably.

〔Example〕

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited only to these Examples.

FIG. 1 is a cross-sectional view showing part of the structure of a liquid crystal display device according to a first embodiment of the present invention. In FIG. 1, 1 is a liquid crystal display panel using a polymer film substrate, 2 is an upper polarizing plate, and 3 Reference numeral denotes a lower polarizing plate (here, a polarizing plate with a reflection plate), 4 a film connector, 5 a rubber member, 6 a drive circuit board, 7 a metal support frame, and 8 a claw-like body. One end of the film connector 4 is heat-sealed to the electrode lead portion of the liquid crystal display panel 1, and the other end is heat-sealed to the drive circuit board 6. It is necessary to select a film connector 4 having lower rigidity than a polymer film substrate, and consideration must be given to the substrate material, thickness, electrode material, electrode thickness, etc. In addition, the film connector 4 and the liquid crystal display panel 1
When making a heat-seal connection to the electrode lead portion of the LCD panel, heat is applied from the connector side. This is to avoid damage to the transparent electrode due to heating from the liquid crystal substrate side. The rubber member 5 has an adhesive layer formed on one side, and after the electrode lead part of the liquid crystal display panel 1 and the film connector 4 are heat-sealed, the rubber member 5 is adhesively fixed to the upper and lower surfaces of the heat-sealed part as shown in the figure. . By caulking the claw-like bodies 8 provided on the metal support frame 7 to the lower surface of the parking circuit board 6, the rubber member 5 is compressed at a constant compression ratio. In this state, the liquid crystal display panel 1 can be fixedly held without being subjected to deformation such as bending due to stress. In addition, since the claw-like bodies 8 are bent and caulked onto the lower surface of the drive circuit board 6, a method of twisting the claw-like bodies provided on the conventional metal support frame on the lower face of the drive circuit board (Japanese Patent Application Laid-Open No. 62-11932) is also available. 210493, 63-179321, etc.) or a method using the elastic repulsive force of claw-like bodies provided on a metal support frame (Japanese Patent Application Laid-open No. 62-187379, 63-217392)
This makes it possible to solve the problem in which the claw-like bodies protrude above the lower surface of the drive circuit board and the thickness of the liquid crystal module itself increases. Furthermore, since there is no need for holes in the N-type circuit board through which the pawls are passed, there is an advantage that the manufacturing process can be reduced.

In Section 22, a specific example of manufacturing the liquid crystal display device according to the first embodiment will be described. A transparent conductive film with a thickness of approximately 800 mm was formed by low-temperature sputtering on a polyester film with a thickness of Loom as a polymer film substrate. The electrode pitch of the electrode lead part is 0.350 μs on the segment side and 0.35 μs on the common side.
．． 480pm, and the electrode widths are o and t'yspa, respectively.
, 0.240-, the film connector has a thickness of 25p.
A polyester film with carbon and Ag layered and printed was used, and an anisotropic conductive film was temporarily pressure-bonded to the heat-sealed portion. The thickness is 0 for the board material of the a-dynamic circuit board.
．． An 8+am glass epoxy plate was used. As the rubber member, a commercially available silicone rubber-based spacer rubber (thickness: 0.5 mm) with a single-sided adhesive was used. The metal support frame has a thickness of 0.
It was formed from a 4@m cold-rolled steel plate, and the rubber member was compressed by 10 to 20% by caulking the claw-like members. The rubber members were fixed at three locations: the segment, the common, and the opposing portion of the segment, and a total of six rubber members were used.

When the liquid crystal display device manufactured as described above was subjected to a drop impact test, no displacement of the liquid crystal display panel was observed even after the test, and the effect of fixing and holding the panel by the rubber member was obtained. In addition, since the liquid crystal display panel was fixed in a flat state without being subjected to deformation such as bending during mounting, the initial disconnection rate was 10%. Furthermore, since the rubber members are fixed to the upper and lower surfaces of the heat-sealed part, no wire breakage was observed even after long-term reliability tests, confirming the reinforcing effect of the heat-sealed part.

FIG. 2 is a perspective view showing a part of the structure of a liquid crystal display device according to a second embodiment of the present invention, in which the same elements as in FIG. 1 are designated by the same reference numerals. This embodiment is structurally different from the first embodiment in that a notch 9 is formed at the bending position of the claw-like body 8. The claw-shaped body 8 heat-seals the liquid crystal display panel 1 and the film connector 4, heat-seals the film connector 4 and the drive circuit board 6, and fixes the rubber member 5 with adhesive, and attaches the metal support frame 7 to these. After being covered, it is bent at the notch 9 and crimped onto the lower surface of the drive circuit board 6. At this time, by accurately determining the formation position of the notch 9 and further bending the claw-like body 8 at right angles, the distance between the support frame 7 and the claw-like body 8 is accurately defined, and the rubber member 5 compression can be controlled more precisely.

FIG. 3 is a perspective view showing a part of the structure of a liquid crystal display device according to a third embodiment of the present invention, in which the same elements as in FIG. 1 are designated by the same reference numerals. This embodiment is structurally different from the first embodiment in that a stopper l is provided on the metal support frame 7.
This is due to the fact that O is provided. - This stopper IO has the following roles. LCD display panel l and finem connector 4
Heat seal with.

After the film connector 4 and the drive circuit board 6 are heat-sealed and the rubber member 5 is fixed with adhesive, and the metal support frame 7 is placed over them, the claw-shaped body 8 is bent at a predetermined position, and the m-drive circuit board 6 is attached. At this time, the claw-shaped body 8 is bent until the end of the stopper 10 comes into contact with the upper surface of the drive circuit board 6. That is, the stopper 10 makes the amount of bending of the claw-like body 8 constant. Therefore, by appropriately setting the height of the stopper 10, the compression of the rubber member 5 can be controlled more accurately as in the second embodiment.

〔Effect of the invention〕

As described in detail above, according to the invention as claimed in claim 1, rubber members are provided on the upper and lower surfaces of the heat seal portion of the liquid crystal display panel and flexible connector using a polymer film substrate, and the rubber members are further compressed. As a result, the liquid crystal display panel can be fixedly held in a flat state without being deformed, and the occurrence of wire breakage due to deformation of the liquid crystal substrate can be avoided.

Furthermore, since the claw-like bodies provided on the support frame are caulked by bending them onto the lower surface of the drive circuit board, the liquid crystal module can be made thinner without the claw-like bodies protruding.

Furthermore, by fixing the rubber member at the heat-sealed portion of the liquid crystal display panel and the flexible connector, the heat-sealed portion is reinforced, and the reliability of the connection is improved.

According to the invention as set forth in claim 2, the notch is formed at the bending position of the claw-like body, which provides the above advantages.

There is an advantage that the compression of the rubber member can be controlled more accurately, and the reliability of fixation and holding is further improved.

According to the third aspect of the invention, the support frame is provided with a stopper that comes into contact with the upper surface of the drive circuit board.

Similar to the invention described in claim 2, there is an advantage that the compression of the rubber member can be controlled more accurately, and the reliability of fixation and holding is further improved.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a part of the structure of a liquid crystal display device according to a first embodiment of the present invention, and FIG.
FIG. 3 is a perspective view showing a part of the structure of a liquid crystal display device according to a third embodiment of the present invention, and FIG. 4 is a perspective view showing a part of the structure of a liquid crystal display device according to a third embodiment of the present invention. 5 is a sectional view illustrating a connection method using a connector, FIG. 5 is a sectional view illustrating a connection method using a heat seal method, and FIG. FIG. 2 is a cross-sectional view showing a structure for suppressing stress. l...Liquid crystal display panel 4...Film connector 5...Rubber member 6...Drive circuit board 7...Support frame 8...Claw-shaped body 9...Notch 10...Stopper

Claims (3)

[Claims] (1) A liquid crystal display panel using a polymer film substrate, a drive circuit board, and a flexible connector whose one end is connected to the liquid crystal display panel and the other end is connected to the drive circuit board by a heat sealing method using a support frame. In the liquid crystal display device which is fixed by sandwiching, the fixing is performed by providing rubber members on the upper and lower surfaces of the heat-sealed portion of the liquid crystal display panel, and using claw-like bodies provided on the support frame body on the lower surface of the drive circuit board. A liquid crystal display device characterized in that the rubber member is compressed between the support frame and the support frame by crimping. (2) a notch is formed at the bending position of the claw-like body;
2. The liquid crystal display device according to claim 1, wherein the claw-like body is bent at this position and caulked to the lower surface of the drive circuit board. (3) The liquid crystal display device according to claim 1 or 2, wherein the support frame is provided with a stopper that comes into contact with the upper surface of the drive circuit board.