JPH08202276A - Liquid crystal display device - Google Patents

Abstract

PURPOSE: To prevent resoldering after a power source introduction line is soldered with a power source supply line, to prevent a solder connection part between the power source introduction line and the power source supply line from projecting out of a bushing and to prevent the projected part from electrically short-circuiting with a metal frame. CONSTITUTION: A back light constituted of incorporating a fluorescent tube 2 and a light transmission plate 8 is arranged under a liquid crystal display panel, and respective power source introduction lines 3 are provided on both ends of the fluorescent tube 2, and the solder connection parts 5 connected to the connection parts 4' of the power source supply lines 4 are provided on the power source introduction lines 3 respectively, and the bushings 1a consisting of plastics covering no whole periphery of the fluorescent tube 2, the power source introduction lines 3 and the power source supply lines 4 are provided on both end parts of the fluorescent tube 2.

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 a backlight including a fluorescent tube is arranged below a liquid crystal display panel.

[0002]

2. Description of the Related Art In a liquid crystal display device, two transparent glass substrates are stacked so that the surfaces on which the transparent electrodes and the alignment film are laminated face each other, and the liquid crystal is sealed between the two substrates. A backlight for irradiating the liquid crystal display panel with light is arranged below the liquid crystal display panel (liquid crystal display element, liquid crystal cell) provided with a polarizing plate on the outside.

Incidentally, the backlight has a plurality of fluorescent tubes arranged in parallel immediately below the liquid crystal display panel (referred to as a direct type), or a light emitted from a light source below the liquid crystal display panel. A light guide plate made of a semi-transparent synthetic resin such as acrylic that guides the light away from the light source to the entire liquid crystal display panel, and the fluorescent light which is the light source is provided along one or two opposite side surfaces of the light guide plate. Arrange the tubes (called the light guide plate type). In addition, a diffusion plate (or diffusion sheet) for diffusing non-uniform light and irradiating the liquid crystal display panel with light uniformly is disposed between the liquid crystal display panel and the fluorescent tubes or light guide plates arranged in a plurality. Further, a reflection plate (or a reflection sheet) that reflects light toward the liquid crystal display panel is arranged under the fluorescent tubes or the light guide plate in which a plurality of fluorescent tubes are arranged.

Such a backlight is, for example, a flat panel display 19 manufactured by Nikkei BP.
94, p. 217.

[0005]

FIG. 4 is a cross-sectional view of a main part showing the vicinity of an end portion of a fluorescent tube of a conventional light guide plate type backlight.

Reference numeral 2 is a fluorescent tube (for example, a cold cathode discharge tube CFL:
Cold Cathode Fluorescent Lamp
e Fluorescent Lamp)), 3 is a power supply line (for example, Dumet wire) provided at the end of the fluorescent tube 2, 4 is a power supply line (that is, a lead wire, a lamp cable), and 4'is a power supply line 3. Connected parts of the connected power supply line 4, 5 are soldered connection parts of the power supply lead-in line 3 and the connection part 4'of the power supply line 4, and 10a are rubber bushes (one piece) provided at both ends of the fluorescent tube 2. (Only shown), 8 is a light guide plate, 6 is a mold case that accommodates a backlight composed of the fluorescent tube 2, the light guide plate 8 and the like, and 7 is a metal frame that covers the lower surface of the mold case 6. The backlight of FIG. 4 is drawn upside down, that is, with the lower surface side facing up. In addition, other members such as a liquid crystal display panel forming the liquid crystal display module are not shown.

The two rubber bushes 10a provided at both ends of the fluorescent tube 2 prevent an electrical short circuit between the solder connecting portion 5 and the metal frame 7 and protect the solder connecting portion 5, and at the same time, It holds both ends and serves to prevent displacement of the fluorescent tube 2 in the case 6.

5A to 5C show a rubber bush 10a.
FIG. 7 is a diagram showing a procedure for attaching the to the fluorescent tube 2. (A) shows the state before the rubber bush 10a is passed through the power supply line 4, (b) after passing it, and (c) shows the state where the rubber bush 10a is covered with the fluorescent tube 2.

As shown in (b), a rubber bush 10a is passed through a power supply line 4 having a connecting portion 4'at its tip, and a power supply line 3 is drawn out to the end of the fluorescent tube 2 and a power supply line. After twisting and twisting the connection portion 4'of 4, the twisted portion is soldered to connect the two. Next, the rubber bush 10a is covered so as to cover the end portion of the fluorescent tube 2 and the solder connection portion 5 as shown in (c). After that, the fluorescent tube 2 held by the two rubber bushes 10a is housed in the housing part of the mold case 6, and the metal frame 7 is covered on the lower surface of the mold case 6 (a perspective view of the backlight according to the present invention). See FIG. 2).

As shown in FIG. 5B, the power supply line 4
When the rubber bush 10a is not passed through the power supply line 4 in order to solder the connection portion 4'of the power supply line 4 and the power supply introduction line 3 after passing the rubber bush 10a through , Soldered connection 4'and power supply lead 3
Then, the rubber bush 10a is again passed through the power supply line 4, and the soldering is performed again.

Further, normally, as shown in FIGS. 4 and 5,
The solder connection portion 5 is formed to be short so that it can be normally accommodated in the rubber bush 10a. However, as shown in FIG.
When the rubber bush 10a is formed to be long, since the rubber bush 10a is soft, a hole is formed in the rubber bush 10a by the solder connection portion 5, and the rubber bush 10a projects outside and the projected portion faces the metal frame 7 side. However, there is a problem that the metal frame 7 is electrically short-circuited. When replacing the rubber bush 10a having a hole, the rubber bush 10a must be passed through the power supply line 4, so the soldered connection part 4'and the power supply lead-in line 3 are removed, and the rubber bush 10a is supplied with power. After passing through the wire 4, the soldering will be redone. Also, after assembling the liquid crystal display module,
If this electrical short circuit occurs, it is troublesome to redo the work. As described above, the conventional configuration increases manufacturing time and cost.

FIG. 7 is a cross-sectional view of a main part (viewed from the direction of arrow C in FIG. 4) showing an example of the rubber bush 10b having a shape different from that in FIG. Also in this conventional example, the bush 10b
Since it is made of rubber and has an annular shape, it has the above problems.

An object of the present invention is to prevent re-soldering of a power supply lead-in wire and a power supply wire after soldering.

Another object of the present invention is to prevent the solder connection portion between the power supply lead-in wire and the power supply wire from protruding outside the bush, and the protruding portion is electrically short-circuited with the metal frame. To prevent this.

[0015]

In order to solve the above-mentioned problems, a liquid crystal display device of the present invention is provided below a liquid crystal display panel.
In a liquid crystal display device in which a backlight configured to include a fluorescent tube is disposed, power supply lines are provided at both ends of the fluorescent tube, and power supply lines are connected to the power supply lines, both ends of the fluorescent tube are provided. Insulator that does not cover the entire circumference of the fluorescent tube, the power supply lead-in wire, and the power supply wire in the vicinity of the portion (that is, it is not annular. Does not pass through the fluorescent tube, the power supply lead-in wire, and the power supply wire) It is characterized in that a bush is provided.

Also, the bush is of a type that is fitted into a recess of a case accommodating the fluorescent tube.

Further, the bush is made of a hard material, such as plastic, to the extent that there is no hole at the connecting portion between the power supply lead wire and the power supply wire.

Further, in a liquid crystal display device in which a case accommodating the fluorescent tube is covered with a metal frame, the bush is provided between the fluorescent tube and the metal frame.

Further, the backlight includes a light guide plate arranged under the liquid crystal display panel, and the fluorescent tube arranged in the vicinity of at least one side surface of the light guide plate along the side surface. It is characterized by

Further, the power supply lead wire and the power supply wire are connected by soldering.

[0021]

According to the present invention, the bush for holding both ends of the fluorescent tube to prevent and protect an electric short circuit of the solder connection portion between the power supply line and the power supply line of the fluorescent tube is the power supply line and the power supply line. , Because it does not cover the entire circumference of the fluorescent tube and does not let these pass through,
Even if there is a work mistake such as forgetting to insert the bush as in the past, it is not necessary to re-solder, and workability is improved.

Further, in the present invention, since the bush is formed of a hard material such as plastic so that there is no hole in the bush due to the solder connecting portion, an electrical short circuit occurs between the solder connecting portion and the metal frame or the like. Can be prevented.

[0023]

【Example】

Example 1 FIG. 1 is a cross-sectional view of a main part (cross-sectional view taken along the line AA of FIG. 2) showing the vicinity of an end portion of a fluorescent tube of a light guide plate type backlight of Example 1 of the present invention, and FIG. It is the whole perspective view seen from the lower surface side of the back light of No. 1.

Reference numeral 2 is a fluorescent tube such as a cold cathode discharge tube, 3 is a power supply lead wire such as a Dumet wire provided at an end of the fluorescent tube 2, 4 is a power supply wire (lead wire, lamp cable), 4 ′ Is a connection portion of the power supply line 4 connected to the power supply line 3 and 5 is a connection portion 4 ′ of the power supply line 3 and the power supply line 4.
1a is a plastic bush provided on each end of the fluorescent tube 2, 8 is a light guide plate, 6 is a fluorescent tube 2, a light guide plate 8, a diffusion sheet (not shown), a reflection sheet, a lamp reflection sheet, etc. A molded case for accommodating the backlight constituted by 7 is a metal frame for covering the lower surface of the molded case 6. In FIG. 2, 9 is a connector connected to an inverter for driving a fluorescent tube (not shown). The backlights of FIGS. 1 and 2 are drawn upside down, that is, with the lower surface side facing up. Also,
Other members such as a liquid crystal display panel forming the liquid crystal display module are not shown.

In the present embodiment, since the bush 1a does not form an annular shape, the fluorescent tube 2 in which the power supply lead-in wire 3 and the connecting portion 4'of the power supply wire 4 at both ends are soldered to each other is provided in the mold case 6. After being housed in a predetermined housing part, the two bushes 1a are fitted into a predetermined housing part provided corresponding to the shape of the bush 1a of the mold case 6.

The two bushes 1a made of an insulating material provided at both ends of the fluorescent tube 2 prevent an electrical short circuit between the solder connection portion 5 and the metal frame 7 and protect the solder connection portion 5. The both ends of the fluorescent tube 2 are held to prevent the fluorescent tube 2 from being displaced within the case 6.

The two power supply lines 4 of the fluorescent tube 2 are
It is housed in a groove formed in the mold case 6 so as to fit the shape of the power supply line 4 almost exactly.

Conventionally, as shown in FIG. 5 and the like, since the bush was passed through the power supply line, it was necessary to insert the bush into the power supply line before solder connection was made. Means that the bush 1a does not cover the entire circumference of the fluorescent tube 2, the power supply lead wire 3, and the power supply wire 4, and
Since the mold case 6 is fitted in a predetermined storage portion, it can be detached even after the solder connection between the power supply lead-in wire 3 and the connection portion 4'of the power supply wire 4, and as described in the prior art, the bushing There is no need to re-soldering even if you make a mistake and forget to put it in. Therefore, workability and assemblability can be improved, and manufacturing time and manufacturing cost can be reduced. In addition, in this embodiment, both ends of the fluorescent tube 2 are held to protect the solder connection portion 5 between the power supply lead-in line 3 of the fluorescent tube 2 and the connection portion 4 ′ of the power supply line 4, and the solder connection portion 5 and the metal. Since the two bushes 1a for preventing an electrical short circuit with the frame 7 made of plastic are made of plastic (see FIG.
Even if the solder connecting portion 5 is formed long, the solder connecting portion 5 can prevent the bush 1a from having a hole, and the solder connecting portion 5 can
Since it does not protrude from a, it is possible to prevent an electrical short circuit between the solder connection portion 5 and the metal frame 7 or the like. Therefore, safety and reliability can be improved.

Embodiments 2 to 4 FIGS. 3A to 3C show examples of bushes 1b to 1d having shapes different from those of FIG. 1 showing Embodiments 2 to 4 of the present invention, respectively, from the direction of arrow C in FIG. FIG. 3 is a main-part cross-sectional view (cross-sectional view corresponding to the BB cutting line in FIG. 2). Also in these embodiments, since the bushes 1b to 1d are made of plastic and can be fitted into the mold case 6, the bushes 1b to 1d have the same effects as those of the first embodiment. The power supply line 4 may be housed in a groove provided in the mold case 6 as shown in (a) or the bushes 1c, 1 as shown in (b) and (c).
It may be placed on d.

Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and it is needless to say that various modifications can be made without departing from the scope of the invention. . For example, in the above embodiment, an example in which the present invention is applied to a light guide plate type backlight is shown. However, in a direct type backlight in which a plurality of fluorescent tubes are arranged directly below a liquid crystal display panel via a diffusion plate. Is also applicable.
Further, the backlight is not limited to the type illustrated in FIG.
The concept of the present invention can be applied to various types of backlights and liquid crystal display modules. Further, since the bush according to the present invention does not cover the entire circumference of the fluorescent tube, the bush is not limited to both ends of the fluorescent tube and may be provided in the middle of the fluorescent tube. Furthermore, two bushes are provided at both ends of the fluorescent tube. Alternatively, one bush extending from both ends to both ends may be provided. It may also be provided above and below the fluorescent tube. In addition, (b) and (c) of FIG.
As illustrated in, the bush may be provided with a storage portion for the power supply line.

[0031]

As described above, according to the present invention,
Since the fluorescent-tube-holding bush is not annular, it can be freely removed, workability and assemblability are improved, and manufacturing time and manufacturing cost can be reduced. Also, by forming the bush with a hard material, the bush is less likely to be damaged by the solder connection portion, and it is possible to prevent the occurrence of an electrical short circuit between the solder connection portion and the metal frame, etc., and to improve safety and reliability. Can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a main part (cross-sectional view taken along the line AA of FIG. 2) showing the vicinity of an end portion of a fluorescent tube of a light guide plate type backlight according to a first embodiment of the present invention.

FIG. 2 is an overall perspective view of the backlight of Example 1 viewed from the lower surface side.

3 (a) to (c) are examples 2 to 2 of the present invention.
4 is an essential part cross-sectional view (cross-sectional view corresponding to the BB cutting line of FIG. 2) viewed from the arrow C direction of FIG. 1 showing an example of a bush having a different shape from FIG.

FIG. 4 is a cross-sectional view of an essential part showing the vicinity of an end portion of a fluorescent tube of a conventional light guide plate type backlight.

5 (a) to 5 (c) are views showing a procedure of attaching a rubber bush to a fluorescent tube by soldering the power supply introduction line and the power supply line of the fluorescent tube in the prior art.

FIG. 6 is a sectional view similar to FIG. 4, showing a state in which a solder connection portion which is formed long and protrudes out of a rubber bush is electrically short-circuited with a metal frame in the prior art.

FIG. 7 is a cross-sectional view of a main part viewed from the direction of arrow C in FIG. 4 showing an example of a rubber bush having a shape different from that of FIG.

[Explanation of symbols]

1a, 1b, 1c ... Plastic bush, 2 ... Fluorescent tube, 3 ... Power supply wire (Dumet wire), 4 ... Power supply wire (lead wire, lamp cable), 4 '... Power supply wire connection part, 5 ... Solder connection part, 6 ... Mold case, 7 ... Metal frame, 8 ... Light guide plate, 9 ... Connector, 10a, 10
b ... Rubber bush.

Claims (7)

[Claims] 1. A backlight including a fluorescent tube is arranged under a liquid crystal display panel, and power supply lines are provided at both ends of the fluorescent tube, and power supply lines are provided to the power supply lines. In the connected liquid crystal display device, a bush made of an insulating material that does not cover the entire circumference of the fluorescent tube, the power supply introduction line, and the power supply line is provided near both ends of the fluorescent tube. apparatus. 2. The liquid crystal display device according to claim 1, wherein the bush is fitted in a recess of a case accommodating the fluorescent tube. 3. The liquid crystal display device according to claim 1, wherein the bush is made of a hard material that does not have a hole due to a connecting portion between the power supply lead wire and the power supply wire. 4. The liquid crystal display device according to claim 1, wherein the bush is made of plastic. 5. A liquid crystal display device in which a case containing the fluorescent tube is covered with a metal frame, wherein the bush is provided between the fluorescent tube and the metal frame. Liquid crystal display device. 6. The backlight includes a light guide plate arranged under the liquid crystal display panel, and the fluorescent tube arranged near at least one side surface of the light guide plate along the side surface. The liquid crystal display device according to claim 1, wherein: 7. The liquid crystal display device according to claim 1, wherein the power supply lead wire and the power supply wire are connected by soldering.