JPS6016899Y2 - liquid crystal display device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a liquid crystal display device in which a liquid crystal display panel and a circuit board are integrated by connecting means such as conductive rubber.

The purpose of the present invention is to provide an extremely compact liquid crystal display device by using a circuit board that is bonded or adhered by wrapping one flexible board around both sides of a hard board such as glass epoxy.

Another object of the present invention is to realize an inexpensive liquid crystal display device by reducing the size of the substrate and by using inexpensive materials such as paper phenol, Bakelite, and plastic for the hard plate.

A cross-sectional view of an embodiment of a conventional liquid crystal display device is shown in FIG.
The driving circuits 2 and 3 of the liquid crystal panel are soldered, the liquid crystal panel 4 is connected to the circuit board 1 with conductive rubber 5 and 6, and the whole is integrated with a case 7 to form a module.

In this case, especially in display devices with a large display capacity such as bar graphs and dot matrices, the number of output lines is large, so it is necessary to use a particularly large number of ICs characterized by a large area for wiring on the circuit board. If this is not the case, the size of the substrate will have to be further increased, resulting in a module that is considerably larger than the size of the liquid crystal display panel, which poses a very serious problem when mounting the module.

Another disadvantage is that the price of the module becomes relatively high due to the use of a large circuit board.

The present invention seeks to eliminate such drawbacks.

FIG. 2 is a cross-sectional view showing one embodiment of the present invention, in which one flexible substrate 9 is glued or adhered to both sides of a hard plate 8 made of a material such as glass epoxy, paper phenol, or plastic, and a drive circuit is mounted on the circuit board. 14 and 15 are soldered and the liquid crystal display panel 10 and conductive rubber 11 and 12 are held together by a case 13 to form a module.

As the electrical connection means, it is possible to use not only conductive rubber but also heat-sealable conductive films and conductive adhesives.

In this embodiment, in particular, if a double-sided flexible board is used, the circuit board will essentially have four layers, the wiring density will increase, and the module can be made extremely compact.

In addition, since the front and back sides of the circuit board can be connected through the wrapped portion of the flexible board, there is no need to make complicated through-holes, which is required for multilayer wiring on ordinary printed circuit boards such as glass epoxy or ceramic boards. This eliminates the need for wiring space, resulting in a more compact and inexpensive board.

On the other hand, flexible substrates can be manufactured in large quantities at low cost by processing them in the form of roll films, and since there are no wiring patterns on rigid boards, it is possible to use inexpensive paper phenol, Bakelite, plastic, etc.

For these reasons, a very inexpensive circuit board can be provided.

Furthermore, if necessary, by treating the surface of the flexible substrate with a resist or a protective layer (overlay), it is possible to make the flexible substrate extremely reliable.

As shown in Figure 2, if the terminals of the liquid crystal display panel are shaped on both sides of the panel and the flexible board is bent in a direction almost parallel to the terminals of the panel, the circuit board will essentially have four layers. good.

This is true not only for liquid crystal display panels for calculators, but especially for dot-type rectangular panels that display alphanumeric displays, graphic displays, etc. This is because it is easier to wire flexible substrates because the wires are generally longer than the non-wired sides and the pitch between wires can be larger.

Also, as shown in FIG. 2, each of the laminated portions of the liquid crystal display panel of the bent flexible substrate 9 between both terminals of the liquid crystal display panel of the bent flexible substrate 9 is A drive circuit 14, 15 may be mounted in the region sandwiched between the conductive rubber 11, 12 on the opposite side.

In dot matrix type liquid crystal display panels, the terminal pitch is increased.

In order to maximize the display capacity in accordance with the drive duty, terminals are formed on both sides of the panel and each is driven by a separate integrated circuit.

In such a case, if the drive section and the panel terminal section are connected through through holes as shown in Fig. 1, a large number of through holes will be required, which will not only make the wiring complicated and difficult, but also make it easier to mount the integrated circuit. Instead, the equipment becomes larger.

However, if it is mounted as shown in FIG. 2, it is sufficient to wire the outside (or inside) of the flexible substrate 9 from the drive circuit 15 to the terminal portion of the conductive rubber 12 portion.

Further, the drive circuit section 14 and the terminal section may be directly connected to the terminal section of the conductive rubber 11 section.

Therefore, the difficulty of wiring a large number of wires from the drive circuit to the terminal portions is eliminated, and the drive circuit can be easily mounted, making the entire device smaller.

Furthermore, although the flexible board 9 is bent, it is one continuous board, so signals such as the power supply section of both drive circuits 14 and 15, drive signal data shift, latch, etc. can be connected via the bent part. The number of interface signal terminals between the present liquid crystal display device and external circuits can be reduced.

As explained above, the present invention provides a liquid crystal display device that is inexpensive, has a high packaging density, and is highly reliable.Due to the high display density of bar graphs, alphanumeric displays, graphic displays, etc., the drive circuit is Particularly great effects can be expected in complex and large-scale cases.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of a conventional liquid crystal display device, in which 1 is a circuit board, 2 and 3 are drive circuits, 4 is a liquid crystal display panel, 5 and 6 are conductive rubber, and 7 is a case. FIG. 2 is a sectional view of an embodiment according to the present invention, in which 8 is a hard plate, 9 is a flexible substrate, 10 is a liquid crystal display panel, 1
1.12 is a conductive rubber, 13 is a case, and 14.15 is a drive circuit.

Claims (1)

[Claims for Utility Model Registration] 1. In a liquid crystal display device formed by integrating a liquid crystal display panel and a circuit board on which a driving circuit for driving the liquid crystal display panel is mounted in a laminated manner, the liquid crystal panel and the circuit board are connected electrically. A liquid crystal display device characterized in that the circuit board is connected to a hard board and a double-sided flexible board is wrapped around both sides of a hard board and integrated by adhesion and adhesion to form a substantially four-layered circuit board. 2 Utility Model Registration Scope of Claim 1 In the liquid crystal display device according to claim 1, terminal portions of the liquid crystal display panel are formed on both sides, and the flexible substrate is bent in a direction substantially parallel to the terminal portions,
A liquid crystal display device characterized by a circuit board having substantially four layers. 3. The liquid crystal display device set forth in Clause 2 of the request for utility model registration is characterized in that a drive circuit portion is formed in each of the laminated portions between both terminals of the liquid crystal display panel made of flexible substrates bent into a laminated state. A liquid crystal display device.