JP3495573B2 - Liquid crystal display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device in which circuit boards are arranged so as to face each other on the back side of a liquid crystal display and they are connected by wiring such as a flat cable.

[0002]

2. Description of the Related Art In a conventional liquid crystal display device, a circuit board is connected to the periphery of a liquid crystal panel via driving elements called TAB and TCP, and they are arranged on the same plane. There is a problem that the area surrounding the effective display surface, that is, the so-called frame portion, is large. Therefore, in order to reduce the frame size, for example, the actual exploitation Sho 63-2452
As disclosed in Japanese Patent No. 9 and the like, it has been proposed that the drive element be configured to be bendable and the circuit board connected via the drive element be arranged on the back side of the liquid crystal panel. In such a configuration in which the circuit board is arranged on the back side of the liquid crystal panel, the circuit boards are arranged on opposite sides of the liquid crystal panel, and wiring such as a flat cable (hereinafter referred to as flat wiring) is used between these circuit boards. If you try to connect from the rear side of the panel, there are the following problems.

First, if the circuit board and the flat wiring are connected by soldering, there is a problem that workability at the time of repair or inspection is deteriorated. Further, in order to improve the workability of solder, the solder connection portion is When it is arranged on the back surface of the circuit board, there is a problem that a separate insulating member is required to insulate the solder connection portion. On the other hand, when the connector is used to connect the circuit board and the flat wiring, the problem of using solder can be improved, but the thickness of the connector increases the thickness of the display device.

Further, when the backlight is arranged on the back side of the liquid crystal panel, it is necessary to arrange the circuit board on the back side of the backlight. In such a case, the light source of the backlight is the liquid crystal panel and the circuit. Since it is sandwiched between the substrates, there is a problem that the workability of replacing the backlight light source is deteriorated.

[0005]

Therefore, the present invention has been made in consideration of the above points, and an object thereof is to provide a structure suitable for narrowing a frame of a liquid crystal display device. Another object is to simplify the structure of the liquid crystal display device.
Let's do it. Another object is to provide a structure with good workability for replacing the backlight light source. Another object is to reduce the thickness of the device.

[0006]

[0007]

[0008]

A liquid crystal display device according to the present invention is connected to a liquid crystal panel, a backlight disposed on the back surface thereof, and two opposite sides of the liquid crystal panel via foldable members. Two circuit boards respectively arranged on the back side of the backlight and wiring arranged on the back side of the backlight so as to connect between the circuit boards are provided, and at least one of the circuit boards is connected to the backlight. A liquid crystal display device arranged in the vicinity of a light source, characterized in that a surplus portion is provided in a length of the wiring to allow movement of the one circuit board when the light source is attached and detached.

In the liquid crystal display device according to the present invention, the frame arranged on the back side of the liquid crystal panel may be provided with an accommodating portion for accommodating the excess portion of the wiring by folding.

A liquid crystal display device of the present invention comprises a liquid crystal panel,
A backlight having a wedge-shaped cross-section, which is arranged on the back surface and has a thickness that decreases from one side of the liquid crystal panel toward the other side opposite to the liquid crystal panel, and is bent to one side of the liquid crystal panel and the other side opposite thereto. 2 connected to each other via flexible members and arranged on the back side of the backlight
Two circuit boards, and one end fixed to one of the circuit boards and the other end removably connected to the upper surface of the other circuit board via a connector and arranged on the back side of the backlight. A liquid crystal display device is characterized in that the connector is arranged in a surplus space portion formed between the backlight and the other circuit board due to the wedge shape of the backlight.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings, taking a transmissive liquid crystal display device as an example. FIG. 1 is a rear view of a main part of the liquid crystal display device 1, and FIG.
FIG. 3 and 4 show a state in the middle of assembling, and FIG. 5 shows a state in the middle of light source replacement, both of which are sectional views corresponding to FIG.

As shown in FIG. 1, the liquid crystal display device 1 has a rectangular flat plate shape. Then, as shown in FIG. 2, a flat plate-shaped liquid crystal panel 2 having a flat rectangular shape constituted by enclosing liquid crystal between a pair of transparent substrates is provided, and two opposing sides 21 and 22 of the liquid crystal panel 2 are provided. The two circuit boards 4 and 5 are connected through a plurality of bendable connecting members 3.

The plurality of connecting members 3 may be composed of only a flexible film-like circuit board, but normally, the film-like circuit board is provided with an LS for driving a liquid crystal.
It is configured by using a driving element called TAB or TCP on which I is mounted. The other end of the connecting member 3, one end of which is connected to the liquid crystal panel 2, is connected to the upper surfaces of the circuit boards 4 and 5 by using solder or the like.

The circuit boards 4 and 5 are the long sides 2 of the liquid crystal panel 2.
1 and 22 are formed by forming a circuit pattern on an insulating substrate having a length similar to that of the first and second parts, and the central portions of the parts are electrically connected to each other via a flat wiring 6 formed by a bendable flat cable or the like. To be done. One end 61 of the flat wiring 6 is connected and fixed to the upper surface of the circuit board 4 by soldering or the like. A connector 63 for detachably connecting the other end 62 of the flat wiring 6 to the upper surface of the circuit board 5.
Is attached. The flat wiring 6 is the circuit board 4
And has a length sufficiently longer than the distance between the circuit boards 5.

On the back surface of the liquid crystal panel 2, a side-edge type backlight 7 having the same plane shape as the liquid crystal panel 2 is formed.
Are placed one on top of the other. The backlight 7 has a wedge-shaped cross section in which the thickness gradually decreases from one end 71 side corresponding to one side 21 of the liquid crystal panel 2 to the other end 72 side corresponding to one side 22 of the liquid crystal panel 2. The backlight 7 is provided with a detachable light source by arranging a linear light source 74 such as a cold cathode tube detachably so as to face one end 71 of the wedge-shaped light guide plate 73 having a large thickness. It constitutes a side edge type surface light source.

By arranging the upper surface of the wedge-shaped backlight 7 so as to face the rear surface of the liquid crystal panel 2 at a constant interval, the rear surface of the backlight 7 on the other end 72 side has a difference in thickness from the one end 71. The surplus space 75 can be secured.

The light source 74 is constructed so that the circuit board 4 located in the vicinity thereof can be detached from the back side of the backlight 7 by moving it to a predetermined position. A lid 76 that covers the light source 74 from the back side is detachable at the time of attachment / detachment.

The liquid crystal display device 1 is provided with a frame body 8 for supporting the liquid crystal panel 2, the backlight 7 and the like at predetermined positions. The frame body 8 is composed of a front frame 81 made of metal, a middle frame 82 made of resin, a back plate (not shown) made of metal, which is provided as necessary. A part of the middle frame 82 is shown in FIG.
As shown in FIG. 5, a wiring housing portion 83 for housing the flat wiring 6 is formed in a portion located on the back surface side of the backlight 7. The wiring accommodating portion 83 has a flat wiring 6
It is formed in the shape of a tunnel that is wider than the width of, and the shape is such that a part (roof part) of the tunnel is cut out.
The cutout portion 84 of the tunnel is provided with guide portions 85 arranged at intervals slightly narrower than the width of the flat wiring 6. And the first and second located at the entrance of the tunnel
The connecting portions 86, 87 and the guide portion 85 serve to accommodate and hold the flat wiring 6.

Next, the procedure for assembling the liquid crystal display device 1 will be described with reference to FIGS. The liquid crystal panel 2 and the circuit boards 4 and 5 and other circuit boards assembled via the connecting member 3 are prepared in an upside down state. Here, one end 61 of the flat wiring 6 is connected to the circuit board 4 in advance by soldering or the like. Then, the backlight 7, the middle frame 82 and the like are sequentially positioned and arranged on the back surface of the liquid crystal panel 2. These are housed in the front frame 81 that has been turned upside down in advance. Then, the other end 62 of the flat wiring 6 is passed through the wiring housing portion 83 and connected to the connector 63. Figure 3
Indicates these states.

Next, the connecting member 3 is bent, and the circuit boards 4 and 5 are moved to the back side of the liquid crystal panel 2. And
The remaining flat wiring 6 is pulled toward the center by using the cutout portion 84 and folded. FIG. 4 shows this state. Here, the connection portion between the flat wiring 6 and the circuit boards 4 and 5, especially the end portion 61 to which the wiring 6 is soldered, is the middle frame 8
Since it is located in the space formed by 2 and is covered by a member having high electric insulation such as the backlight 7 arranged on the back surface of the liquid crystal panel 2, it is not necessary to separately provide a member for insulation, Can be simplified. Since the connector 63 for connecting the flat wiring 6 and the circuit board 5 is arranged in the extra space portion 75 formed by the wedge-shaped light guide plate, it is possible to effectively prevent the thickness increase of the liquid crystal display device 1 by the connector 63. .

The excess portion of the folded flat wiring 6 is inserted into the guide portion 85 and the second connecting portion 87 so that it is integrated with the middle frame 82 as shown by the arrow in the folding range in FIG. Can be held at. FIG. 2 shows this state. By folding and accommodating the excess portion of the flat wiring 6 in this manner, the flat wiring 6 can be reliably held without play. Since the wiring accommodating portion 83 has a guide portion 85 formed by a notch having a width narrower than that of the wiring 6, this portion can effectively function as a function of accommodating the wiring 6 and an operation portion when moving the wiring. . After that, back cover (not shown)
By positioning and mounting as necessary,
The liquid crystal display device 1 is completed.

When replacing the light source 74 of the backlight 7, the back cover (not shown) is removed and the flat wiring 6 is used.
4 is taken out from the wiring accommodating portion 83 and brought into a state as shown in FIG. Next, the excess portion of the wiring 6 is moved to the circuit board 4 side by utilizing the cutout portion 84 of the wiring housing portion 83. As a result, only the circuit board 4 on the side where the light source 74 is arranged in the vicinity can be moved to the state perpendicular to the panel 2 as shown in FIG. As a result, the circuit board 4 and the wiring 6 can be moved to a range that does not hinder the attachment and detachment of the light source 74 and the lid 76 thereof, and the workability of attaching and detaching the light source 74 can be improved. After removing the lid 76, exchanging the old and new light sources 74, and closing the lid 76, the apparatus is assembled according to the same procedure as the assembly.

Although the above embodiments have been described by taking a transmission type liquid crystal display device as an example, the present invention is not limited to this, and the present invention can be applied to, for example, a reflection type liquid crystal display device. You can also When applied to a reflective liquid crystal display device, the backlight 7 in the above embodiment is not necessary,
Instead, the structure for reflection may be arranged inside the liquid crystal panel 2 or on the back side of the liquid crystal panel 2.

Since the circuit boards 4 and 5 are arranged on the back side of the liquid crystal panel 2 as described above, a structure suitable for narrowing the frame of the liquid crystal display device 1 can be provided. Also, the wiring 6
By providing the connecting portion between the circuit board 4 and the circuit board 4 and 5 between the circuit board 4 and 5 and the liquid crystal panel 2 or the backlight 7, the liquid crystal panel 2 or the backlight 7 functions as an insulating material to simplify the structure. Can be planned. In addition, since the wiring 6 connecting the circuit boards 4 and 5 is provided with the surplus portion, the circuit board 4 covering the light source portion 74 of the backlight 7 can be easily moved, and the light source replacement workability of the backlight 7 is excellent. Can be Since the frame 8 is provided with the portion 83 for accommodating the surplus portion of the wiring 6, the surplus wiring can be accommodated reliably and compactly. Further, since the connector 63 is arranged by effectively utilizing the surplus space portion 75 of the wedge-shaped backlight 7, it is possible to suppress an increase in thickness due to the connector 63.

[0025]

As described above, according to the present invention, since the wiring for connecting the circuit boards is provided with the surplus portion, the light source replacement workability of the backlight can be improved. Since the frame is provided with the portion for accommodating the excess portion of the wiring, the excess wiring can be reliably accommodated. By arranging the connector in the surplus space of the wedge-shaped backlight, the device can be made thin. As a result, a structure suitable for narrowing the frame of the liquid crystal display device can be provided.

[Brief description of drawings]

FIG. 1 is a rear view of an essential part showing an embodiment of a liquid crystal display device of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a cross-sectional view of essential parts showing an assembled state of the embodiment.

FIG. 4 is a cross-sectional view of essential parts showing an assembled state of the same embodiment.

FIG. 5 is a cross-sectional view of essential parts showing a light source exchange state of the same embodiment.

[Explanation of symbols]

1 Liquid crystal display 2 LCD panel 3 connection members 4 circuit board 5 circuit board 6 flat wiring 63 connector 7 Backlight 74 Light source 8 frame 82 Middle frame 83 Wiring housing

   ─────────────────────────────────────────────────── ─── Continued front page       (56) Reference JP-A-4-296818 (JP, A)                 JP-A-8-122806 (JP, A)                 JP-A-2-306219 (JP, A)                 JP-A-63-302666 (JP, A)                 JP-A-6-3688 (JP, A)                 Actual Development Sho 61-42578 (JP, U)

Claims (3)

(57) [Claims] 1. A liquid crystal panel and a back panel arranged on the back surface thereof.
Clyde and the two sides of the LCD panel that face each other
Connected via a bendable member,
Two circuit boards respectively arranged on the back side, and the circuit
Arranged on the back side of the backlight so as to connect the boards.
At least one of the circuit board,
Liquid crystal display device arranged near the light source of the backlight
And the transfer of the one circuit board when the light source is attached or detached.
The length of the wiring has an extra part to allow the movement.
A liquid crystal display device characterized by the above. 2. A frame arranged on the back side of the liquid crystal panel.
In order to fold and accommodate the excess part of the wiring,
The liquid crystal display according to claim 1, further comprising a container portion.
apparatus. 3. A liquid crystal panel and a liquid crystal disposed on the back surface thereof.
Thickness from one side of the crystal panel to the other side opposite
A backlight with a wedge-shaped cross section that reduces
Fold it along one side of the LCD panel and the opposite side.
Each of them is connected through a bendable member,
Two circuit boards placed on the back side of the light and one end
Fixed to one of the circuit boards, the other end is the other circuit board
It is detachably connected to the upper surface of the
LCD display with wiring arranged on the back side of the backlight
The device is caused by the wedge shape of the backlight.
Excessive space formed between the backlight and the other circuit board
A liquid characterized by arranging the connector in the space
Crystal display device.