JPH0447740Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a liquid crystal display device, and particularly to a liquid crystal display device formed by modularizing a liquid crystal display panel and a drive circuit for driving the display.

(b) Conventional technology In recent years, as an alternative to CRT display devices, liquid crystal display devices have been used as an alternative to CRT display devices, as disclosed in the article “Flat panel display aimed at displaying documents and images” in the January 2, 1984 issue of Nikkei Electronics. Various display devices are being developed, such as those using displays, electroluminescence displays, and plasma displays, and are currently capable of achieving low power consumption and large capacity. The future potential of liquid crystal display devices has been highly evaluated.

By using such a liquid crystal display device, small 3-inch or 5-inch television receivers, which are called pocket televisions, have been realized. However, in the liquid crystal display devices of existing pocket television receivers, the liquid crystal display panel and the driving circuit board for displaying the panel are installed separately inside the receiver.
Most of these were connected by flexible lead wires. In this case, the assembly work of the liquid crystal display device, such as the work of connecting flexible lead wires, becomes complicated, and furthermore, the drive circuit board is provided outside the liquid crystal display panel, and there is a dead space for assembly. This placed a limit on the miniaturization of the television receiver itself.

(c) Problems to be solved by the invention The present invention has been developed in view of the above points, and by integrally modularizing the liquid crystal display panel and the drive circuit for driving the display, this invention can be made into a module. The present invention aims to simplify the assembly work and downsize the liquid crystal display device.

(d) Means for Solving the Problems The liquid crystal display device of the present invention includes a liquid crystal display panel having a display area in the center, and a display area of the panel having external dimensions substantially equal to the external dimensions of the panel. Laminated circuit boards with openings corresponding to
Both of these laminates are housed in a frame.

(E) Effect According to the liquid crystal display device of the present invention, the outer dimensions of the frame can be set to the extent that the liquid crystal display panel can be accommodated, that is, the outer dimensions are the minimum necessary for a display device, thereby eliminating the need for this type of display device. Enlargement can be avoided.

(F) Embodiment An exploded perspective view of an embodiment of the liquid crystal display device of the present invention is shown in FIG. 1, a sectional view thereof is shown in FIG. 2, and main parts thereof are shown in FIGS. 3 to 11.

As shown in FIGS. 1 and 2, the liquid crystal display device of this embodiment includes a liquid crystal display panel 1 that performs a shutter action on a pixel basis against natural light or light from a backlight to display a light-transmissive image; Circuit board 2 on which a drive circuit is formed to drive this
and a zebra rubber 3 for electrically connecting the panel 1 and the circuit board 2. These are integrated into a frame-shaped metal frame 8, 9 consisting of two front and back panels provided with a display window. It is made into a module by storing it in a modular manner.

Each component will be explained in detail below.

As shown in the plan view of FIG. 3A and the side view of FIG. Polarizing plates 1c and 1c are attached to the outer surfaces of the glass substrates 1a and 1b, respectively. This liquid crystal display panel 1 adopts an active matrix type in which a TFT is bonded to each pixel electrode as disclosed in Japanese Patent Laid-Open No. 58-25689, and the panel dimensions are
107mm x 129mm while the center dimension is 76mm x 100mm
is the image display area (indicated by a broken line in the figure). Of the two substrates 1a and 1b, the terminal-equipped substrate 1a provided with the TFT has a larger area than the other substrate 1b. That is, in the peripheral part of the terminal-equipped board 1a that further extends from the outer peripheral part of the other board 1b,
Timing signal input terminals (left and right sides) 1e, 1e and video signal input terminals (upper and lower sides) 1f, 1f for on/off control of the TFT are formed.

Therefore, the liquid crystal display panel 1 that is modularized
Since the external dimensions of the terminal-equipped substrate 1a are determined by the terminal-equipped substrate 1a, cross-shaped point marks 1d for positioning are formed at each corner of the terminal-equipped substrate 1a.

As shown in FIG. 4, the circuit board 2 is composed of a printed circuit board on which circuit elements are mounted and wired, and has a frame shape with approximately the same external dimensions as the liquid crystal display panel 1, and a rectangular window 2c in the center thereof is a frame-shaped board on which circuit elements are mounted and wired. It is set to coincide with or be wider than the effective image display area 1g in the center of the image display area 1g. The circuit elements of the substrate 2 include an IC 2b for generating timing signals or video signals for driving the liquid crystal display panel 1, and other chip components 2e such as resistors. For example, 15
IC2b... is placed, and on the back side, for example, 9
Chip parts 2e... are placed. and,
The liquid crystal display panel 1 is located around the substrate 2.
Timing signal output terminals (left and right sides) 2d, 2d and video signal output terminals (upper and lower sides) 2f, 2f are provided corresponding to each terminal. Furthermore, on the back side of this board 2, there are separated flexible flat lead wires 10 and 10'.
Two terminals are provided to which RGB image signals, IC control signals, etc. should be input.

The electrical connection between the circuit board 2 and the liquid crystal display panel 1 is made using a sebra rubber 3 compressed between the terminals of both.
..., but at this time, the corresponding terminals of both must be exactly vertically opposed. For this reason, each corner of the circuit board 2 is also provided with point marks 2a, similar to the liquid crystal display panel 1.
are formed, and these marks 1d..., 2a
Due to the alignment, the corresponding terminals of the circuit board 2 and the liquid crystal display panel 1 face each other vertically, and accurate connection with the zebra rubber 3 becomes possible. The zebra rubber 3 has a sandwich structure in which an anisotropic conductive part 3a is sandwiched between two insulating parts 3b, and is maintained at an appropriate compression ratio (around 15%).
A good electrical connection is made. An example of such zebra rubber 3 is the product name "SR" manufactured by Shin-Etsu Polymer Co., Ltd.
connector" can be used.

The combination of the above liquid crystal display panel 1, circuit board 2, and zebra rubber 3 basically forms a metal frame 8, 9.
The circuit board 2 includes ICs 2b... and chip parts 2e mounted on the front and back surfaces of the circuit board 2.
Frame-shaped mold plates 4, 5 and a spacer 6 for protecting ... are joined with adhesive or double-sided tape.

As shown in the plan view of FIG. 5A and the side view of FIG.
Escape holes 4a for resin potting are formed at locations corresponding to b. That is, instead of separately providing a frame for resin potting for each IC 2b bonded to the circuit board 2 by die bonding, wire bonding, etc., Relief hole 4a
By ..., frames for resin potting for all IC2b... are formed at once. Therefore, by potting (dropping) resin onto the IC2b exposed from the escape hole 4a and allowing it to solidify naturally, a resin mold of the IC2b can be made. However, at this time, if there is a gap between the circuit board 2 and the first mold board 4, the potting resin flows out from this gap and insulates the terminals 2d, 2d, 2f, 2f. In particular, it is necessary to prevent steps from forming around IC2b of the circuit board 2, as there is a risk of an accident. Therefore, in the circuit board 2 of this embodiment, as shown in FIG. 6, the solder resist 2g (indicated by hatching), which is the surface insulating film of the printed circuit board on which the metal wiring pattern forming the circuit board 2 is formed, is used as the electrode for the IC 2b. By applying the coating to surround the IC2b... area, the area around it is flattened and the level difference therein is eliminated. in this way,
IC2b... Since there is no gap between the circuit board 2 and the first molded plate 4 in the surrounding areas, there is no need to apply adhesive to the entire joint surface of both 2 and 4 at several locations. Both 2 and 4 may be bonded together with a single adhesive.

As mentioned above, the first mold plate 4 has IC2b...
In addition to acting for the mold of..., the second mold plate 5 as shown in the plan view of FIG. Cutouts 4c..., 5b... are provided in the cutouts 4c..., 5b... and the zebra rubber 3... is inserted into the cutouts 4c..., 5b... to position the rubber 3.... Further, the first and second mold plates 4 and 5 are used for the liquid crystal display panel 1 and the circuit board 2.
Therefore, the first and second mold plates 4, 5 are placed so that the point marks 1d..., 2a... for alignment of these 1, 2 are visible.
Through holes 4b..., 5a... are formed at each corner. In addition, these through holes 4b..., 5a...
A notch may be formed instead. These frame-shaped first and second mold plates 4 and 5 have substantially the same outer dimensions, but the inner dimensions of the second mold plate 5 are larger than those of the first mold plate 4. On the other hand, the second
The inner dimension (opening dimension) of the mold plate 5 is the lower glass substrate 1 of the liquid crystal display panel 1 adjacent thereto.
It is larger than the outside dimension of b, and prevents these from coming into contact. These first and second mold plates 4 and 5 are made of an insulating material such as epoxy resin or silicone resin, and it is also possible to integrally mold them.

As shown in the plan view of FIG. 8A and the side view of FIG.
A protective relief hole 6a... is formed. The material of this spacer 6 may be the same as that of the mold plates 4 and 5 described above. Furthermore, this spacer 6 has escape holes 6a' and 6a'' for the soldered parts of the input terminals for the two flexible flat lead wires provided at two places on the back side of the circuit board 2, and
Two flexible flat lead wires 1 as shown in the plan view of FIG.
Concave grooves 6b having the minimum necessary depth to escape the thickness of 0.10' are formed on the surface facing the circuit board 2 in a pattern as shown by hatching in FIG. That is, the longer lead wire 10 is connected to the upper hole 6.
The lead wire 10' is pulled out downward from the position a' in the concave groove 6b, and is overlapped with the shorter lead wire 10' pulled out further downward from the position 6a'' in the lower hole.
Soldering portions 10a, 10b, 10a', 10b' are provided at both ends of each lead wire 10, 10'. Therefore, no gap is created between the circuit board 2 and the spacer 6 due to the presence of the lead wire 10. This is important in terms of preventing compressive strain on the zebra rubber 3 mentioned above.
This avoids conduction defects.

The circuit board 2 to which the liquid crystal display panel 1, the mold plates 4 and 5, and the spacer 6 are bonded, and the zebra rubber 3 between these two 1 and 2 are formed into a frame formed by press-molding an iron plate as shown in FIG. It is elastically held between a back side metal frame 8 having a shape of a shape and a front side metal frame 9 having a frame shape formed by press forming an iron plate as shown in FIG. In both FIGS. 10 and 11, A shows a plan view, Ro to C show side views, and F shows an enlarged sectional view. That is, the elastic locking pieces 8a on the outer circumferential wall of the back side metal frame 8 are fitted into locking holes 9a formed at the tongue pieces on the outer circumferential wall of the front side metal frame 9, and are thereby connected. The zebra rubber 3... is moderately compressed between the two frames 8 and 9. Therefore, the liquid crystal display panel 1
Since the surrounding area of the surface of the panel 1 will be crimped to the inner surface of the metal frame 9 on the front side, in this embodiment, in order to prevent the glass substrate 1a of the panel 1 from breaking, the strip-shaped 4 A cushion material 7 made of a sheet of Teflon is interposed between these 1 and 9. It is also possible to use this cushion material 7 integrally in the shape of a frame, but in any case, it is necessary to exclude the point marks 1d of the liquid crystal display panel 1 at each corner. In connection with this, window holes 9c are formed in each corner of the front metal frame 9 so that the point marks 1d..., 2d... of the liquid crystal display panel 1 and the circuit board 2 can be visually seen. There is.

In addition, screw holes 8b..., 9b... are provided in the respective peripheral walls of these two metal frames 8, 9 for finally fixing these two metal frames 8, 9 with screws. 2 on the surrounding wall of frame 8
A slit 8c is formed through which the stacked flexible flat lead wires 10, 10' are both pulled out to the outside.

Next, the assembly of each component as described above will be briefly described.

First, the circuit board 2 to which the spacer 6 mold plates 4 and 5 are bonded is placed in the back metal frame 8 fixed to a jig. At this time, the flexible flat lead wires 10, 10' are drawn out from the slit 8c.

In this state, the notches 4c of the mold plates 4 and 5...
Terminals 2b, 2b, 2 exposed from 5b...
f, 2f are surrounded by the mold plates 4, 5 and the peripheral wall of the back metal frame 8, and zebra rubber 3... are inserted into these positions, respectively. That is, these mold plates 4 and 5 and the back metal frame 8 are used as the zebra rubber position determining material.

Thereafter, the terminals 1e, 1e, 1f, 1f of the liquid crystal display panel 1 are placed on the four sheets of zebra rubber 3.... At this time, the point marks 1d at the four corners of the liquid crystal display panel 1 are precisely aligned with the point marks 2a at the four corners of the circuit board 2. In this state, the cushion material 7...
By placing the front side metal frame 9 through the frame and pressing it downward, both frames 8 and 9 are elastically connected. Finally, once you have reconfirmed that the above point marks 1d..., 2a... that are visible from the window holes 9c... at the four corners of the front metal frame 9 match, connect both metal frames 8, 9 to the screw holes 8b... ...,
Fix with screws using 9b... In this way, a modularized liquid crystal display device is completed.

As mentioned above, such a module has frames 8 and 9.
Since each plate-shaped component is crimped by the elastic force of the zebra rubber 3 within the compressed state, if there is a gap or step between the components, the zebra rubber 3 in the compressed state
. . . compressive strain occurs, leading to poor conduction between the liquid crystal display panel 1 and the circuit board 2, but this problem is solved in the device of this embodiment. That is, even if the flexible flat lead wire is partially interposed, by forming the groove for relief in the spacer 6 as described above, gaps and steps can be eliminated, and the zebra rubber 3... The compression state of is made uniform.

(G) Effects of the invention The liquid crystal display device of the present invention can be set to the minimum necessary size, which is close to the area size of only the liquid crystal display panel that dominates the display area, so the entire device can be miniaturized. Structural reliability is improved because the outer peripheries of the liquid crystal display panel and the circuit board can be housed in the frame at the same time.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of an embodiment of the liquid crystal display device of the present invention, FIG. 2 is a sectional view of the device of the present invention, and FIGS. 3 to 11 are views showing the constituent parts of the device of the present invention, respectively. . 1...Liquid crystal display panel, 2...Circuit board, 3...
...Zebra rubber, 4, 5...Mold plate, 6...Spacer, 7...Cushion material, 8, 9...Metal frame.

Claims (1)

[Scope of utility model registration request] A liquid crystal display panel having a display area in the center and a circuit board having external dimensions substantially equal to the external dimensions of the panel and having an opening corresponding to the display area of the panel are stacked, and a laminate of these two is arranged. A liquid crystal display device that is characterized by being housed within a frame.