JPH0650035U - Matrix type liquid crystal display device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a liquid crystal display device capable of easily and stably forming electrical conduction between a ground wiring of a printed wiring board 4 and a metal cover 6. [Structure] Large cross-section portion 5a of a coupling plug 5 made of conductive rubber
Protrusions 5b and 5c protruding from both end surfaces of the protrusion are provided on the printed wiring board 4 on the ground wiring thereof.
b, a hole 6a for fitting the projection 5c is provided in the metal cover 6 so as to face the hole 4a, and the projections 5b, 5c of the connecting wire 4 are respectively fitted to the hole 4a, 6a, and the printed wiring board 4
And, the metal cover 6 is coupled, and the metal cover 6 and the ground wiring of the printed wiring board 4 are electrically connected.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a liquid crystal display device, and more particularly to a matrix type liquid crystal display device.

[0002]

[Prior art]

 In recent years, regulations on electromagnetic noise standards and safety standards for matrix type liquid crystal display devices have become strict. As a measure against the above regulations, the electrical connection between the metal frame of the liquid crystal display and the ground wiring of the printed wiring board is established, the potential of the metal frame is fixed at the ground level, and the impedance of the ground wiring of the printed wiring board is fixed. The reduction is being implemented.

FIG. 3 is a sectional view showing a means for electrically connecting a conventional metal frame and a ground wiring of a printed wiring board. In this figure, 1 is a color filter substrate, 2 is an array substrate laminated with the color filter substrate, 3 is a plastic frame supporting the array substrate 2, and 4 is a plastic frame 3 supported by the plastic frame 3 to drive a liquid crystal panel. Printed circuit board for the purpose, 6 is a metal frame that presses and positions each constituent member against the plastic frame 3, 7 is a TAB-IC, and 8 is interposed between the metal frame 6 and the TAB-IC 7. Silicon rubber 9 is a screw for fixing the metal frame 6 to the plastic frame 3, and 10 is a spacer rubber interposed between the metal frame 6 and the TAB-IC 7.

In the conventional matrix type liquid crystal display device having the above-mentioned configuration, the electrical connection between the metal frame 6 and the ground wiring of the printed wiring board 4 is established as follows. That is, as shown in FIG. 3, it is assumed that the spacer rubber 10 is attached and fixed to the printed wiring board 4, and is fixed to the metal frame 6 together with the screw 9, or as shown in FIG. Instead, the metal frame 6 and the printed wiring board 4 are soldered to establish electrical continuity.

[0005]

[Problems to be solved by the device]

 The above conventional structure has the following problems. That is, as shown in FIG. 3, when the screws 9 are fastened together, the electrical resistance is likely to increase due to insufficient tightening of the screws 9. If the tightening is insufficient, the potential of the metal frame 6 becomes unstable and electromagnetic radiation noise increases. In addition, in the conductive formation by soldering shown in FIG. 4, defective soldering easily occurs on the metal frame 6 side, an increase in electrical connection resistance is seen, and the workability of soldering itself is poor, which is favorable for manufacturing. No

The present invention has been made based on the above circumstances, and provides a matrix type liquid crystal display device capable of ensuring electrical connection between a metal frame and a ground wiring of a printed wiring board.

[0007]

[Means for Solving the Problems]

 The matrix type liquid crystal display device of the present invention comprises a matrix type liquid crystal panel, a printed wiring board necessary for driving the liquid crystal panel, a metal frame for protecting the liquid crystal panel and the print wiring board, and the metal frame. Also, in the liquid crystal display device in which the ground wirings of the printed wiring board are electrically connected to each other, both end surfaces are provided with protrusions that are respectively inserted into the holes penetrating the ground wiring portion of the printed wiring board and the holes provided in the metal frame. In addition, the electrical continuity is formed by a coupling plug made of a conductive rubber.

[0008]

[Action]

 In the matrix type liquid crystal display device of the present invention having the above structure, the electrical connection between the printed wiring board ground wiring and the metal cover is formed by the projection printed wiring board and the metal provided on both end faces of the conductive rubber coupling plug. Since it is obtained by fitting the cover into the cover, it does not cause an increase in electrical resistance due to insufficient tightening of screws or various problems due to this.

[0009]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. 1 in which the same parts as those in FIGS. 3 and 4 are denoted by the same reference numerals is a cross-sectional view showing a main part of an embodiment of the present invention. In this figure, the printed wiring board 4 is arranged on the plastic substrate 3 as in the conventional liquid crystal display device. Then, a hole 4a into which the coupling plug 5 made of a conductive rubber is fitted is provided so as to penetrate a part of the ground wiring of the printed wiring board 4, and the same applies to a position of the metal frame 6 facing the hole 4a. The hole 6a for the purpose of is provided. Similar to the spacer rubber 10 in the conventional liquid crystal display device shown in FIGS. 3 and 4, the coupling plug 5 has a rectangular large cross section having a function of maintaining a space between the metal frame 6 and the TAB-IC 7. It has a portion 5a, a protrusion 5b having a shape protruding from one end surface thereof and fitted into the hole 4a, and a protrusion 5c having a shape protruding from the other end surface and fitting into the hole 6a. The protrusions 5b and 5c have a function of determining the relative position between the metal frame 6 and the printed wiring board 4, respectively.

FIG. 2A is a perspective view showing details of the coupling plug. In this figure, the large cross-section 5a of the connecting line 5 and the projections 5b and 5c are made of conductive rubber, and an insulating silicon rubber coating 11 is provided on the outer periphery of the large cross-section 5a.

In the coupling plug 5, the projection 5b is fitted into the hole 4a of the printed wiring board 4, the hole 6a is engaged with the projection 5c, and the printed wiring board 4 is covered with the metal cover 6. A caulking portion (not shown) is provided around the hole 6a of the metal cover 6, and by caulking the caulking portion, the connecting wire 5 and the metal frame 6 form an electrical contact, Electrical connection is established between the metal cover 6 and the ground wiring of the printed wiring board 4.

In the liquid crystal display device of the present invention having the above-mentioned configuration, the formation of electrical continuity between the printed wiring board ground wiring and the metal cover is not obtained by joint tightening with a coupling screw, but is made of a conductive rubber. Since the projections provided on both end surfaces of the coupling plug are obtained by fitting the printed wiring board and the metal cover, the electrical resistance increases due to insufficient tightening of screws, the potential of the metal frame becomes unstable, and the electromagnetic radiation It does not cause an increase in noise.

FIG. 2B is a perspective view of a modified example of the main part. In this modification, the conductive rubber portion of the coupling plug 5 has a large number of thin metal wires 5e whose surfaces are gold-plated in the insulating silicon rubber material 5d, and the ends thereof are aligned. Each part is exposed and embedded in both end faces of the above-mentioned coupling plug 5. With the coupling plug 5 having this structure, the same operation and effect as those of the embodiment shown in FIG. 1 can be obtained.

[0014]

[Effect of device]

 As is apparent from the above, in the liquid crystal display device of the present invention, the electrical connection between the metal frame and the ground wiring of the printed wiring board does not need to be co-tightened with the screw, and the coupling plug protrusion made of conductive rubber is Since it is obtained by fitting into both, the electrical conduction can be easily formed. Further, the protrusion not only determines the relative position between the metal frame and the printed wiring board, but also prevents the coupling stopper itself from being displaced. Further, since the coupling plug in the present invention also serves as the spacer rubber in the conventional liquid crystal display device, the number of parts can be reduced and the structure of the device can be simplified.

[Brief description of drawings]

FIG. 1 is a sectional view showing an essential part of an embodiment of the present invention.

FIG. 2A is an enlarged perspective view of the essential part of the embodiment, and FIG.
FIG. 4 is an enlarged perspective view of a modified example of the main part.

FIG. 3 is a cross-sectional view showing a means for electrically connecting a conventional metal frame and a ground wiring of a printed wiring board.

FIG. 4 is a cross-sectional view showing a modified example of the electrical conduction means.

Claims (2)

[Scope of utility model registration request] 1. A matrix type liquid crystal panel, a printed wiring board necessary for driving the liquid crystal panel, a metal frame for protecting the liquid crystal panel and the printed wiring board, and the metal frame and the ground of the printed wiring board. In a liquid crystal display device in which wirings are electrically connected to each other, a projection penetrating into a hole penetrating a ground wiring portion of the printed wiring board and a projection fitted into a hole provided in the metal frame are provided on both end surfaces, and are made of conductive rubber. A matrix type liquid crystal display device characterized in that the electrical conduction is formed by a coupling plug. 2. A plurality of fine wires, the surfaces of which are plated with gold, are aligned in the insulating silicone rubber, and both ends thereof are buried so that both ends thereof are exposed at both end faces of the insulating silicone rubber. 2. The matrix type liquid crystal display device according to claim 1, wherein the coupling plug is formed by using a conductive rubber.