WO1997034189A1

WO1997034189A1 - Liquid crystal display

Info

Publication number: WO1997034189A1
Application number: PCT/JP1996/000594
Authority: WO
Inventors: Hirofumi Fukumoto; Hiroyuki Takahashi; Takayuki Iura; Yoshio Sugaya
Original assignee: Hitachi, Ltd.; Hitachi Device Engineering Co., Ltd.
Priority date: 1996-03-11
Filing date: 1996-03-11
Publication date: 1997-09-18
Also published as: JP3599348B2

Abstract

A liquid crystal display provided with a liquid crystal element, circuit boards on which are mounted electronic parts used for driving the element and which are arranged along at least the adjacent two sides of the element, a case which houses the element and the boards, and a connecting wiring board which electrically connects the circuit boards to each other at a corner between the above-mentioned two sides of the element. The connecting wiring board is superposed on the element. Thus, the width of the so-called picture frame is reduced and the corner of the liquid crystal display is effectively utilized.

Description

Specification

Liquid crystal display

〔Technical field〕

The present invention relates to a liquid crystal display device used for a display unit that outputs information and an image of an information processing device and a display unit that displays information and an image of a device that transmits information. In particular, the present invention relates to a liquid crystal display device having a region where a driving circuit for driving a liquid crystal display element is provided in a display region of the liquid crystal display device.

(Background technology)

With the dawn of the mobile and computing era, thinner and lighter display devices and lower power consumption are expected to achieve practically portable performance o

In recent years, liquid crystal display devices have been frequently used as such thin and lightweight display devices with low power consumption.

FIG. 1 is a plan view illustrating a configuration example of a liquid crystal display device, and 100 is a liquid crystal display element. The liquid crystal display element 100 has a substantially rectangular shape, and a driving circuit for driving the liquid crystal display element is provided along the side of the liquid crystal display element. Reference numeral 600 denotes a circuit board in which an electronic circuit is formed on a printed wiring board. The output from the circuit board 600 is transmitted to each of the crystal display elements via a semiconductor IC 200 formed in a tape carrier system. Input to terminal. The circuit board is divided for each side of the liquid crystal display element, and a connection wiring board for electrically connecting the circuit board to the circuit board is provided at a corner formed by two substantially orthogonal sides of the liquid crystal display element. Is provided ^.

A liquid crystal display device on which such a drive circuit is mounted has a substantially rectangular case. Can be stored. A display window is opened in the case, and the display area of the liquid crystal display element can be observed through the display window. The area extending from the display window to the periphery of the case is usually called a picture frame. The area occupied by the frame accommodates the circuit board, the semiconductor Ic, and the connection wiring board described above.

Fig. 2 shows a personal computer with a conventional liquid crystal display device 900 mounted on it. In the conventional liquid crystal display device, a frame portion 920 around the display area and a mounting portion 910 for attaching the liquid crystal display device to a personal computer are used for display. .

However, there is a demand for a liquid crystal display device mounted on such a personal computer to make the width of the frame as small as possible. Eliminating wasted space and creating an aesthetic appearance as a display device

Around the corner of the liquid crystal display element, a connection wiring board for electrically connecting the circuit boards is arranged, which prevents the width of the frame around the corner of the liquid crystal display element from being reduced, Further, components other than the connection wiring board, for example, the mounting portion 9100 could not be arranged around the corner of the liquid crystal display element.

Therefore, the present invention has been made based on such circumstances, and one object of the present invention is to provide a liquid crystal display device that can reduce the area of the frame, that is, t. Another object of the present invention is to provide a liquid crystal display device capable of effectively utilizing a region around a corner of a liquid crystal display element.

[Disclosure of the Invention]

A liquid crystal display element, a circuit board on which electronic components for driving the liquid crystal display element are mounted, a case accommodating the liquid crystal display element and the circuit board, and at least two sides adjacent to the liquid crystal display element Each is placed And a connection wiring board for electrically connecting the circuit board at a corner formed by the two sides of the liquid crystal display element. The liquid crystal display element so that it overlaps o

A liquid crystal display element, an upper case and a lower case for sandwiching and housing the liquid crystal display element between them, and a print for driving the liquid crystal display element and arranged along at least two adjacent sides of the liquid crystal display element A substrate, a flexible wiring board for electrically connecting the printed circuit board at a corner formed by two sides of the liquid crystal display element, and an upper case and a lower case fixed at the corner of the liquid crystal display element. Having a fixed part,

The flexible wiring board is provided between the fixing portion and the liquid crystal display element.

A liquid crystal display element, a circuit board on which electronic components for driving the liquid crystal display element are mounted, a case for housing the liquid crystal display element and the circuit board, and at least two sides adjacent to the liquid crystal display element. At least at a corner formed by the two sides of the liquid crystal display element, and at least a connection wiring board for electrically connecting the circuit board. The connection wiring board is disposed so as to overlap the liquid crystal display element, and a mounting portion for an external device is provided at the corner.

[Brief description of drawings]

FIG. 1 is a plan view showing a conventional example of a liquid crystal display device.

FIG. 2 is an external view showing a conventional example of a personal computer equipped with a liquid crystal display device.

FIG. 3 is a perspective view of the liquid crystal display device according to the present invention. FIG. 4 is a schematic perspective view showing a liquid crystal display device according to the present invention.

FIG. 5 is a diagram showing the surface of the flexible wiring board according to the present invention. FIG. 6 is a diagram showing the back surface of the flexible wiring board according to the present invention. FIG. 7 is a cross-sectional view of the flexible wiring board according to the present invention.

FIG. 8 is a schematic assembly view of the liquid crystal display device according to the present invention.

FIG. 9 is a schematic view showing a corner of the liquid crystal display device according to the present invention.

FIG. 10 is an outline view showing a personal computer equipped with the liquid crystal display device of the present invention.

FIG. 11 is a plan view of a mold according to the present invention.

FIG. 12 is a diagram showing an embodiment of a mold according to the present invention.

FIG. 13 shows a conventional example of a mold.

[Best mode for carrying out the invention]

FIG. 3 is a perspective view of an embodiment of the liquid crystal display device according to the present invention. Printed circuit boards 600A, 600B and 6100 are arranged around the liquid crystal display element 100, and the printed circuit board and the liquid crystal display element are semiconductor ICs formed by a tape carrier method. Connected via 200 A, 200 OB.250. The liquid crystal display element to which the printed wiring board is connected is held by a frame-shaped mold 800 and held between the upper case 350 and the lower case 300. In order to fix the upper case 350 and the lower case 300, fixed portions 360 and 310 are provided, respectively. A backlight 400 serving as a light source of the liquid product display device is provided below the liquid crystal display element 100. This backlight is formed by applying a cold paint to a cold cathode fluorescent tube 430, a light guide plate 440 made of an acryl plate for uniformly irradiating the light from the cold cathode fluorescent tube to a liquid crystal display element, and a metal plate. Reflector 450 formed by diffusion, diffuses light from light guide plate Milky-white diffuser composed of 450 powers. At a corner A of the liquid crystal display element, a flexible wiring board 700 for electrically connecting the printed wiring boards 600B and 6100 is provided.

FIG. 4 is a perspective view showing a schematic configuration of a liquid crystal display element used in the liquid crystal display device according to the present invention. In FIG. 4, 120 is a segment electrode substrate, 110 is a common electrode substrate, 140 is a segment electrode, and 130 is a common electrode 170 is a sealing material. The common electrode substrate 110 is formed of a substantially rectangular transparent substrate made of glass or the like, and a plurality of common electrodes 130 formed of strip-shaped transparent electrodes are formed.

The segment electrode substrate 120 is also formed of a transparent substrate made of glass or the like, which is also substantially rectangular, and the segment electrode 140 made of a strip-shaped transparent electrode is formed on the segment electrode substrate.

Although not shown, a polarizing plate is provided outside the common electrode substrate 110 and the segment electrode substrate 120. 195 shows a region on the common electrode substrate 110 where the polarizing plate is provided.

In the liquid crystal display element shown in FIG. 4, the segment electrode substrate 120 and the common electrode substrate 110 are overlapped with a fixed gap therebetween via a sealing material 170, and the sealing material is a segment electrode. A frame is provided at the edge of each substrate between the substrate and the common electrode substrate, and the sealing material, the segment electrode substrate, and the common electrode substrate form a container in which the two substrates are bonded together with the above gap kept. The liquid crystal is sealed inside and assembled.

F ig. As shown in 4, the common electrode and the segment electrode, which interlink with straight mutually, and the common electrode, _c the common electrode 1 3 0 intersection of the segment Bok electrodes constitute one pixel, the segment electrode 1 20 extend to the sides of the common electrode substrate 110 and the segment electrode substrate 120, respectively. The external connection terminals 150 and 160 for electrically connecting the terminals are formed.

As described above, the liquid crystal display element 100 has a substantially rectangular common electrode substrate 110 and a segment electrode substrate 120 overlapped with each other so that the common electrode 130 and the segment electrode 120 intersect, and each of the common electrode and the segment electrode is extended. Since the external connection electrodes 150 and 160 are provided at the positions where they exist, as shown in FIG. 3, the driving ICs 200 A, 200 B and 250 for driving the liquid crystal display element, the printed wiring boards 600 A and 600 B and 610 are provided around at least two sides of the liquid crystal display element. A flexible substrate 700 is used to electrically connect the printed wiring boards provided on these two sides.

FIG. 5 is a plan view of the flexible wiring board according to the present invention as viewed from the front, and FIG. 6 is a plan view of the flexible wiring board according to the present invention as viewed from the back. The flexible wiring board 700 is formed by forming wiring with a conductor on a flexible board, and FIG. 5 and FIG. 6 include two front and back sides of the flexible board 760. Layer wiring 710 is formed. FIG. 7 shows a cross-sectional view taken along line BB ′ in FIG. The two-layer wiring 710 is electrically connected between the two layers of wiring at the terminal part 720, and is connected to the printed wiring board by soldering at the terminal part 720. In the two-layer wiring, if the signal wiring 730 having a high frequency is arranged to be surrounded by the GND wiring 740, there is an effect of preventing leakage of high-frequency noise and the like.

In addition, the power supply wiring 750 and the GND wiring 740 are wide to reduce the impedance of the wiring and allow a large amount of current to flow.

Fig. 8 shows an enlarged perspective view of the corners formed by two adjacent sides of the liquid crystal display device of Fig. 3. Fig. 8 is a liquid crystal display element 100 with a drive IC 200 B, 250 mounted in a tape carrier system, and a drive IC 200 B, Connect 250 to printed circuit board 600B and 610, connect the backside of printed circuit board 600B and 610 with flexible printed circuit board 700, and Reference numeral 0 denotes a state in which the liquid crystal display element on which the drive circuit is mounted is held and stored in the upper case 360 and the lower case 300.

In FIG. 8, first, there is a lower case 300 which forms a part of the outer frame of the liquid crystal display device. The lower case 300 has a box shape provided with a fixing portion 310 at a corner thereof for fixing to a later-described upper case.

Further, a common electrode drive circuit 250 made of, for example, a semiconductor IC formed by a tape carrier method is arranged between the printed wiring board 6100 and the liquid crystal display element 100, and the common electrode drive circuit is provided. The electrode terminal of 250 is connected to the external connection terminal 150 of the common substrate 110 on one side, and to the electrode terminal on the common-side printed wiring board 61 0 on the other side. Have been.

In addition, a segment-side printed wiring board 600B is arranged on the side of the segment substrate of the liquid crystal display element 100 on the side of the external connection terminal. Further, a segment electrode driving circuit 200B made of a semiconductor IC formed by, for example, a tape carrier method is arranged between the segment side printed wiring board 600B and the liquid crystal display element 100B. The electrode terminal of the segment electrode driving circuit 200 B is connected at one end to an external connection terminal 160 of the segment substrate 120.

Here, the printed wiring boards 6100 and 600B are separate from each other, and their ends in the longitudinal direction extend to such an extent that they come into contact with the fixing portions 310 of the lower case 300. It is formed in. While ensuring that the area of each wiring board 610, 600B is equal to or greater than a predetermined value, If the length is to be made as small as possible, the length will be such that it comes into contact with the fixed part 310.

These printed wiring boards 6100 and 600B need to be electrically connected, and the connection is made via a flexible wiring board 700. FIG. 8 shows the positional relationship before the flexible wiring board 700 is connected to the back surfaces of the wiring boards 6100 and 600B for easy understanding. Actually, the flexible wiring board 700 is directly connected to the back surfaces of the wiring boards 6100 and 600B.

Fig. 9 shows a schematic enlarged view showing the arrangement of each part in Fig. 3A. In order to make it easy to understand the positional relationship between the flexible wiring board 700 and other parts, the back side of the wiring boards 6100 and 600B is shown from the side opposite to FIG. . The flexible wiring board 700 is a force arranged so as not to abut on the fixing portion 310, and the flexible wiring board 700 is bent along the corner formed by the two sides of the liquid crystal display element 100. And a part thereof overlaps the non-display portion 180 of the liquid crystal display element 100.

The reason why the wiring of the flexible wiring board 700 is arranged so as to overlap with the liquid crystal display element is that the fixed part 360 of the upper case 350 and the liquid crystal display element 100 adjacent to the fixed part 360 are fixed. This is because the above-described arrangement of the flexible wiring board 700 is most effective to effectively use the limited space of 0. However, the liquid crystal display element 100 has a display area 190, and if the flexible wiring board 700 overlaps the display area 190, the aesthetic appearance of the display device is impaired. It is necessary not to overlap the display area 190. In addition, there is a region 195 on which a polarizing plate is provided, and when the flexible wiring substrate 700 overlaps with the region 195 on which the polarizing plate is provided, the thickness of the liquid crystal display device increases. It is also necessary that the wiring substrate 700 does not overlap the region 195 where the polarizing plate is provided. For this reason, the width of the flexible wiring board 700 is limited, and the flexible wiring board 700 has a multilayer structure so that a large number of wirings with a narrow I and a width can be provided.

In addition, a flexible wiring board 700, a fixing portion 360 of the upper case 350, and the like are provided at a corner 950, which is located on an extension of the wiring boards 6100 and 600B. Instead, as shown in FIG. 10, a liquid crystal display device mounting portion 910 of a personal computer can be provided.

Also, the mold 800 holding the liquid crystal display element is one of the molds 800 on which the flexible wiring board 700 is disposed because the flexible wiring board 700 and the liquid crystal display element are arranged to overlap. The part 8 10 has been deleted by the thickness of the flexible wiring board. FIG. 11 shows the mold 800 used in the present invention. Fig. 12 shows an enlarged view of the C portion of Fig. 11, and Fig. 13 shows a conventional example of the same C portion. The portion indicated by reference numeral 8100 in FIG. 12 is removed from the conventional mold 8300, and the thickness of the flexible wiring board 700 arranged over the liquid crystal display element is reduced by the thickness of the mold. The thickness is reduced.

As is clear from the above description, according to the liquid crystal display device of the present invention, the flexible wiring board is disposed so as to overlap the liquid crystal display element. Therefore, the limited space between the fixed portion of the lower case and the liquid crystal display substrate adjacent to the fixed portion can be effectively used.

For this reason, it is not necessary to increase the space (width) between the liquid crystal display substrate and the frame wall of the lower case, so that the width can be made smaller than before. Become. [Industrial applicability]

According to the liquid crystal display device configured as described above, the connection wiring board is arranged at the corner of the liquid crystal display element so that the wiring at the corner of the liquid product display element is overlapped with the liquid crystal display element. Other members can be provided. Therefore, the limited space between the liquid crystal display element and the liquid crystal display element near the corner of the liquid crystal display element can be effectively used.

Further, it is not necessary to increase the width of the frame of the liquid crystal display element and the case accommodating the liquid crystal display element, so that the width can be made smaller than before.

Also, a mounting portion for mounting the liquid crystal display device can be provided at a corner of the liquid crystal display device on another external device on which the liquid crystal display device is mounted, so that the width of the mounting portion can be made smaller than before. Become.

Claims

The scope of the claims

1. Electrical connection between the liquid crystal display element, the first circuit board, the second circuit board, and the first circuit board and the second circuit board respectively arranged along the sides of the liquid crystal display element. A wiring board to be connected to the

The liquid crystal display device, wherein the wiring substrate is provided so as to overlap the liquid crystal display element.

2. A liquid crystal display element, a first circuit board and a second circuit board respectively arranged along at least two sides adjacent to the liquid crystal display element, and an angle formed by the two sides of the liquid crystal display element A wiring board for electrically connecting the first circuit board and the second circuit board to each other;

3. A liquid crystal display element, an upper case and a lower case for sandwiching and housing the liquid crystal display element between them, and each being arranged along at least two adjacent sides of the liquid crystal display element by driving the liquid crystal display element. A flexible printed circuit board for electrically connecting the printed circuit board at a corner formed by the two sides of the liquid crystal display element, and the upper case at a corner of the liquid crystal display element. A fixing portion for fixing the lower case and

The liquid crystal display device, wherein the flexible wiring board is provided between the fixing portion and the liquid crystal display element.

4. The liquid display element, a printed circuit board that is disposed along at least two sides that are adjacent to and substantially orthogonal to the liquid crystal display element and drives the liquid crystal display element, and the two sides that are substantially orthogonal to the liquid crystal display element are A flexible wiring board for electrically connecting the printed circuit board at a corner to be made;

The flexible wiring board is provided on two sides substantially orthogonal to the liquid crystal display element. A liquid crystal display device, wherein the liquid crystal display device is disposed so as to be substantially orthogonal to and along the liquid crystal display element.

5. A liquid crystal display element, a printed circuit board that is arranged along at least two sides that are adjacent to and substantially orthogonal to the liquid crystal display element, and drives the liquid crystal display element, and two substantially orthogonal sides of the liquid crystal display element are formed. A flexible wiring board for electrically connecting the printed boards at the corners,

The liquid crystal display device, wherein the flexible wiring board is provided so as to overlap with the liquid crystal display element, and the flexible wiring board is provided with wiring in multiple layers.

6. The multilayer flexible wiring board for electrically connecting the printed circuit boards has a signal and power supply wiring used for driving the liquid crystal display element, and the wiring surrounds the signal line with a power supply line. The liquid crystal according to claim 6,

7. A liquid crystal display element, a printed circuit board that is arranged along at least two sides that are adjacent to and substantially orthogonal to the liquid crystal display element and that drives the liquid crystal display element, and two substantially orthogonal sides of the liquid crystal display element are formed. A flexible wiring board that electrically connects the printed boards at the corners, and a mold that holds the liquid crystal display element, the print board, and the flexible wiring board,

The flexible wiring board is disposed so as to overlap with the liquid crystal display element, and the mold is configured such that a portion where the flexible wiring board and the liquid crystal display element overlap with each other is removed by at least the thickness of the flexible wiring board. Liquid crystal display device.

8. A liquid crystal display element, a first circuit board and a second circuit board respectively arranged along at least two sides adjacent to the liquid crystal display element, A wiring board for electrically connecting the first circuit board and the second circuit board at corners formed by two sides of the display element;

The liquid crystal display device, wherein the wiring substrate is disposed so as to overlap the liquid crystal display element, and a mounting portion for attaching another device is provided at the corner.