JPH0744579U - Liquid crystal display - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce the external dimensions of the frame. A liquid crystal display panel 1 having a display area substantially matching the display window of the frame and a drive circuit for driving the display panel 1 are formed in the space of the frame-shaped frames 8 and 9 having the display window. In the liquid crystal display device, a circuit board 2 having a shape substantially matching the frames 8 and 9 and a connecting means 3 for electrically connecting the board and the display panel are housed. Drive circuits are formed on both sides of
Further, by overlapping the panel 1 and the board 2 so that the outer peripheral portion of the display panel 1 overlaps with the drive circuit formed on at least one surface of the circuit board 2,
The outer dimensions of the circuit board are reduced, and as a result, the outer dimensions of the frame are reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device in which a liquid crystal display panel and a drive circuit for driving the display are modularized.

[0002]

[Prior art]

 In recent years, as an alternative to the CRT display device, a device using a liquid crystal display as disclosed in the article "Flat Panel Display for Document and Image Display" in the January 2, 1984 issue of Nikkei Electronics. Various display devices such as those using an electroluminescence display or those using a plasma display are under development, and currently liquid crystal displays are capable of achieving low power consumption and large capacity. The future potential of the device is highly evaluated.

By using such a liquid crystal display device, a small-sized 3-inch or 5-inch television receiver called a pocket television has been realized. However, the liquid crystal display device of the existing pocket television receiver is equipped with a liquid crystal display panel and a drive circuit board for displaying the liquid crystal display panel separately in the receiver, and these are connected by a flexible lead wire. There was almost everything. In this case, the assembly work of the liquid crystal display device such as the connection work of the flexible lead wire is complicated, and moreover, the drive circuit board is provided outside the liquid crystal display panel, and the dead space for assembling these parts. Due to the existence of, there was a limit to the miniaturization of the television receiver itself.

[0004]

[Problems to be solved by the device]

 The present invention has been made in view of the above points, and by forming the drive circuits on both surfaces of the circuit board, the area of the circuit board is reduced, and the outer peripheral portion of the liquid crystal display panel is formed on at least one surface of the circuit board. This is to reduce the outer dimensions of the frame by overlapping the panel and the board so as to be overlapped with the driven circuit, thereby reducing the outer dimensions of the circuit board.

[0005]

[Means for Solving the Problems]

 A liquid crystal display device according to the present invention comprises a liquid crystal display panel having a display area substantially matching the display window of the frame in a frame-like frame provided with a display window, and a drive circuit for driving the liquid crystal display panel. A liquid crystal display device comprising: a circuit board in which a circuit board is formed and which substantially matches the frame-like frame; and a connecting means for electrically connecting the circuit board and the liquid crystal display panel. The drive circuit is formed on both sides of the circuit board, and the outer peripheral portion of the liquid crystal display panel overlaps with the drive circuit of the circuit board.

[0006]

[Action]

 According to the liquid crystal display device of the present invention, a liquid crystal display panel having a display region substantially matching the display window of the frame in a space of a frame-like frame provided with a display window, and a drive for driving the liquid crystal display panel A drive circuit is housed on both sides of the circuit board, in which a circuit board having a circuit formed therein and substantially conforming to the frame-like frame and connection means for electrically connecting the circuit board and the liquid crystal display panel are housed. And the outer peripheral portion of the liquid crystal display panel is overlapped with the drive circuit of the circuit board, the external dimensions of the circuit board are reduced by overlapping the liquid crystal display panel and the circuit board. As a result, the outer dimensions of the frame are reduced.

[0007]

【Example】

 An exploded perspective view of an embodiment of the liquid crystal display device of the present invention is shown in FIG. 1, its sectional view is shown in FIG. 2, and its essential parts are shown in FIGS.

As shown in FIGS. 1 and 2, the liquid crystal display device according to the present embodiment is a liquid crystal display device panel that performs a pixel-by-pixel shutter action for natural light or light from a backlight to perform light-transmissive pixel display. 1, a circuit board 2 on which a drive circuit for driving the same is formed, and a zebra rubber 3 for electrically connecting the panel 1 and the circuit board 2 to each other. This is a module that is integrally housed in the provided frame-shaped metal frames 8 and 9 having two front and back surfaces.

Each component will be described in detail below. As shown in the plan view of FIG. 3 (a) and the side view of the same surface (b), the liquid crystal display panel 1 has a liquid crystal substance interposed between two glass substrates 1a and 1b provided with electrodes. Polarizing plates 1c and 1c are attached to the outer surfaces of the two glass substrates 1a and 1b, respectively. As the liquid crystal display panel 1, an active matrix type in which a TFT is connected to each pixel electrode as disclosed in Japanese Patent Laid-Open No. 58-25689 is adopted, and the size of the central portion is 76 mm × the size of the panel is 105 mm × 127 mm. 100 mm is the image display area (shown by the broken line in the figure). Note that the terminal-equipped substrate 1a of the two substrates 1a and 1b on which the TFT is provided has a larger area than the other substrate 1b. That is, in the peripheral part of the substrate with terminal 1a extending further from the outer peripheral part of the other substrate 1b, timing signal input terminals (left and right sides) 1e and 1e and video signal input terminals are provided for the on / off control of the TFT. (Upper and lower sides) 1f and 1f are formed.

Therefore, since the external dimensions of the liquid crystal display panel 1 to be modularized are determined by the board with terminals 1a, cross-shaped point marks 1d ... Are formed at each corner of the board with terminals 1a. Has been done.

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 whose outer dimensions are almost the same as those of the liquid crystal display panel 1. It is set to match or be wider than the effective image display area 1g at the center of the display panel 1. The circuit elements of the substrate 2 include an IC 2b for producing a timing signal or a video signal for driving the liquid crystal display panel 1 and a chip portion 2e such as a resistor, and the surface of the substrate 2 (the liquid crystal surface). For example, fifteen ICs 2b ... Are mounted on the side facing the display panel 1) and, for example, nine chip portions 2e are mounted on the back side thereof. In the peripheral portion of the substrate 2, timing signal output terminals (left and right sides) 2d and 2d and video signal output terminals (upper and lower sides) 2f and 2f are provided corresponding to the terminals of the liquid crystal display panel 1. Is provided. Furthermore, on the back side of this substrate 2, two flexible flat lead wires 10 and 10 'are separated, and the R. G. Two terminals are provided to which the B image signal, the IC control signal, and the like are to be input.

The circuit board 2 and the liquid crystal display panel 1 are electrically connected by the zebra rubber 3 which is compressed between the terminals of the circuit board 2. At this time, the corresponding terminals of the two are exactly facing each other vertically. There must be. For this reason, point marks 2a are formed at the respective corners of the circuit board 2 as in the case of the liquid crystal display panel 1 described above. By aligning the marks 1d ..., 2a. Corresponding terminals of the display panel 1 correspond to the upper and lower sides, enabling accurate connection with the zebra rubber 3 ... The zebra rubber 3 has a sandwich structure in which the anisotropic conductive portion 3a is sandwiched between the two insulating portions 3b and 3b, and is maintained at an appropriate compression rate (around 15%) for good electrical conductivity. The connection is made. As such a zebra rubber 3, for example, the product name "SR connector" manufactured by Shin-Etsu Polymer Co., Ltd. can be used.

The combination of the liquid crystal display panel 1, the circuit board 2 and the zebra rubber 3 described above is basically housed in the metal frames 8 and 9, but the circuit board 2 is mounted on the front and back surfaces thereof. Frame-shaped mold plates 4 and 5 and spacers 6 for protecting the ICs 2b ... And chip products 2e ... Are joined by an adhesive or a double-sided tape.

As shown in the plan view of FIG. 5A and the side view of FIG. 5B, the first mold plate 4 has a frame shape that substantially matches the circuit board 2. Relief holes 4a for resin potting are formed at locations corresponding to ICs 2b on the surface. That is, a frame for resin potting is not separately provided for each of the ICs 2b ... Which are bonded to the circuit board 2 by die bonding, wire bonding, etc. The escape holes 4a ... Form the resin potting frame for all the ICs 2b. Therefore, resin molding of IC2b ... can be made by potting (dripping) resin onto IC2b ... Exposed from the escape holes 4a. However, at this time, if the resin at the time of potting has a gap between the circuit board 2 and the first mold plate 4, the potting resin flows out from this gap and insulates the terminals 2d, 2d, 2f, 2f. Since there is a risk of accidents that occur, it is necessary to make sure that there are no steps in the IC 2b ... Surrounding portion of the circuit board 2. Therefore, in the circuit board 2 of this embodiment, as shown in FIG. 6, the solder resist 2g (shown 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 for the IC (2b). By coating the electrode portion so as to surround it, the IC2b ... Surrounding portion is flattened and the step is eliminated. In this way, since there is no gap between the circuit board 2 and the first mold plate 4 at the IC2b ... Surrounding portion, it is necessary to apply an adhesive to the entire bonding surface of these two and two. Alternatively, the adhesives 2 and 4 may be adhered to each other with an adhesive at only a few places.

As described above, the first mold plate 4 acts not only to mold the ICs 2b, but also to be joined to the first mold plate 4, the plan view of FIG. 7A and the same FIG. As shown in the side view of the second mold plate 5, notches 4c, 5b ... Are provided on the outer side of the second mold plate 5, and zebra rubber 3 is inserted into the notches 4c, 5b. Is done. Further, since the first and second mold plates 4 and 5 are present between the liquid crystal display panel 1 and the circuit board 2, point marks 1d ..., 2a ... for aligning these 1 and 2 are provided. Through holes 4b ..., 5a ... Are formed in the respective corners of the first and second mold plates 4 and 5 so as to be visible. Note that notches may be formed instead of the through holes 4b ..., 5a. The outer dimensions of the frame-shaped first and second mold plates 4 and 5 are substantially the same, but the inner dimension of the second mold plate 5 is larger than that of the first mold plate 4. On the other hand, the inner dimension (opening dimension) of the second mold plate 5 is larger than the outer dimension of the glass substrate 1b below the liquid crystal display panel 1 which is close to the second mold plate 5 and prevents these from contacting each other. The first and second mold plates 4 and 5 can be formed integrally with, for example, an insulating material such as epoxy resin or silicon resin, or these materials.

As shown in the plan view of FIG. 8A and the side view of FIG. 8B, the spacer 6 is provided on the back surface of the circuit board 2 at a position corresponding to each chip portion 2e. The holes 6a ... Are formed. The material of the spacer 6 may be the same as that of the mold plates 4 and 5. Further, the spacer 6 is provided with escape holes 6a 'and 6a' 'for the soldering portions of the two flexible flat lead wire input terminals provided at two positions on the back side of the circuit board 2 and these holes 6a' and 6a. '' To remove the thickness of the two flexible flat lead wires 10 and 10 'as shown in the plan view of FIGS. 9 (a) and 9 (b), which are pulled out in the same direction (downward in the figure) from the soldering portions. The concave groove 6b having the minimum necessary depth is 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 pulled out downward from the upper hole 6a 'position in the groove 6b, and is overlapped with the shorter lead wire 10' pulled further downward from the lower hole 6a '' position. Has been. In addition, soldering portions 10a, 10b, 10a ', 10b' are provided at both ends of each lead wire 10, 10 '. Therefore, there is no gap between the circuit board 2 and the spacer 6 due to the presence of the lead wire 10. This is important in preventing the compressive strain on the zebra rubber 3 described above, and avoids a poor conduction of the zebra rubber 3.

The above-mentioned liquid crystal display panel 1, the mold plates 4, 5 and the circuit board 2 to which the spacers 6 are joined, and the zebra rubber 3 ... Between these two 1, 2 are press-formed with an iron plate as shown in FIG. It is elastically sandwiched by a frame-shaped back side metal frame 8 and a frame-shaped front side metal frame 9 formed by press forming an iron plate as shown in FIG. 10 and 11, (A) is a plan view, (B) to (C) are side views, and (F) is an enlarged cross-sectional view. That is, the elastic locking pieces 8a of the outer peripheral wall portion of the back side metal frame 8 are fitted into the engaging holes 9a formed in the tongue pieces of the outer peripheral wall portion of the front side metal frame 9, and are joined by this. The zebra rubber 3 is appropriately compressed between the two frames 8 and 9. Therefore, since the peripheral portion of the surface of the liquid crystal display panel 1 is pressure-bonded to the inner surface of the metal frame 9 on the surface, in the present embodiment, the glass substrate 1a of the panel 1 is prevented from cracking. Therefore, a cushion material 7 made of four strip-shaped Teflon is interposed between these 1 and 9. It should be noted that this cushion material 7 can also be used by being integrated in a frame shape, but in any case, it is necessary to exclude the point marks 1d ... Locations of the liquid crystal display panel 1 at each corner. In relation to this, window holes 9c ... Are formed in the respective corners 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 seen.

Further, screw holes 8b ..., 9b ... for finally screwing and fixing the two metal frames 8 and 9 are provided on the peripheral wall portions of the two metal frames 8 and 9, respectively, and A slit 8c is formed in the peripheral wall of the back metal frame 8 so that two of the flexible flat lead wires 10 and 10 'in a superposed state can be pulled out to the outside.

Next, a brief description will be given to the assembly of the above-mentioned components. First, the circuit board 2 to which the spacer 6 and the mold plates 4 and 5 are joined is arranged in the back side metal frame 8 fixed to the jig. At this time, the flexible flat lead wires 10 and 10 'are pulled out from the slit 8c to the outside. In this state, the terminals 2b, 2b, 2f, 2f exposed from the notches 4c, 5b of the mold plates 4, 5 are surrounded by the peripheral walls of the mold plates 4, 5 and the back metal frame 8, The zebra rubber 3 ... Is inserted into this position, respectively. That is, these mold plates 4 and 5 and the back side metal frame 8 are used as a zebra rubber position defining material.

Then, the terminals 1e, 1e, 1f, 1f of the liquid crystal display panel 1 are placed on the four zebra rubbers 3 ... At this time, the point marks 1d at the four corners of the liquid crystal display panel 1 are accurately aligned with the point marks 2a at the four corners of the circuit board 2. Then, in this state, the front surface metal frame 9 is placed via the cushioning material 7 ... And crimped downward, so that both frames 8 and 9 are elastically coupled. Finally, if we could reconfirm the above-mentioned point marks 1d ..., 2a ... that can be seen through the window holes 9c ... at the four corners of the surface metal frame 9, we could screw both metal frames 8, 9 into the screw holes 8b. Secure with screws using 9b. Thus, the modularized liquid crystal display device is completed.

As described above, in this module, since each plate-shaped component is crimped by the elastic force of the zebra rubber 3 in the frames 8 and 9, if each component has a gap or a step, The zebra rubber 3 in the compressed state has a compressive strain, which causes a defective conduction between the liquid crystal display panel 1 and the circuit board 2. However, this apparatus solves this problem. That is, even if the flexible flat lead wire is partially interposed, as described above, by forming the recess groove for escape in the spacer 6, the gap or step is eliminated, and the compressed state of the zebra rubber 3 ... It is assumed to be equal.

[0022]

[Effect of device]

 By forming the drive circuit on both sides of the circuit board, the area of the circuit board can be reduced, and the outer peripheral portion of the liquid crystal display panel can be overlapped with the drive circuit formed on at least one side of the circuit board. Since the outer dimensions of the circuit board are reduced by overlapping the panel and the board, the outer dimensions of the frame can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment of a liquid crystal display device of the present invention.

FIG. 2 is a sectional view of the device of the present invention.

FIG. 3 is a view showing components of the device of the present invention.

FIG. 4 is a diagram showing the components of the device of the present invention.

FIG. 5 is a view showing components of the device of the present invention.

FIG. 6 is a view showing components of the device of the present invention.

FIG. 7 is a view showing components of the device of the present invention.

FIG. 8 is a view showing components of the device of the present invention.

FIG. 9 is a view showing components of the device of the present invention.

FIG. 10 is a view showing components of the device of the present invention.

FIG. 11 is a view showing components of the device of the present invention.

[Explanation of symbols]

 1 Liquid crystal display panel 2 Circuit board 3 Zebra rubber 4 Mold plate 5 Mold plate 6 Spacer 7 Cushion material 8 Metal frame 9 Metal frame 9 Flexible flat lead wire 10 'Flexible flat lead wire

Claims (1)

[Scope of utility model registration request] 1. A liquid crystal display panel having a display area substantially matching the display window of the frame and a drive circuit for driving the liquid crystal display panel are formed in a space of a frame-like frame provided with a display window. In a liquid crystal display device comprising a circuit board having a shape substantially matching the frame-like frame and a connecting means for electrically connecting the circuit board and the liquid crystal display panel, the circuit board is provided on both sides. A liquid crystal display device comprising a drive circuit, wherein an outer peripheral portion of the liquid crystal display panel overlaps with a drive circuit formed on at least one surface of the circuit board.