JPH10333126A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability by realizing a large screen and miniaturization with a simple constitution and simplifying a manufacturing process by eliminating the coating film of the lead wire of a light source and directly embedding a conductor in the housing of back light part. SOLUTION: The coating film of the lead wire of a cathode fluorescent tube 50 and a groove for inserting and fixing the lead wire are eliminated, and the conductor 64a is embedded in the housing 40 of the back light part. The housing 40 is a resin molded product, and the conductor 64a is easily embedded by embedding molding. Thus, the width of the housing 40 of the back light part of the liquid crystal display device is made smaller by W(a space covered by the coating film of the lead wire) than that of a conventional housing. Also, the conductor 64a is embedded in the housing 40 and constitutes an integral part, so that the number of components is reduced and an assembling process is simplified. Since the conductor 64a is embedded in the housing 40, a movable part causing backlash or the like is eliminated, so that durability to excessive mechanical impact and vibration is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal display device. More specifically, the present invention relates to a liquid crystal display device in which the non-light emitting area of the backlight portion is reduced to reduce the external dimensions and improve the reliability.

[0002]

2. Description of the Related Art A liquid crystal display device is a notebook type personal computer.
It is used in a very wide range such as a computer, an electronic organizer, a portable information terminal or a monitor display of a video camera.

FIG. 2 is a cross-sectional view illustrating a schematic configuration of such a liquid crystal display device. That is, the liquid crystal display device 1
00 has a structure in which a liquid crystal panel 102 and a backlight unit 104 are stacked roughly. Backlight unit 1
04 serves as a planar light source. The liquid crystal panel 102 controls the transmittance of light from the backlight unit 104 to form a predetermined image.

The liquid crystal panel 102 has two opposing transparent substrates and a liquid crystal layer sandwiched between these substrates. An electrode is formed on the transparent substrate, and by applying a predetermined electric field to each pixel, the alignment state of the liquid crystal is changed to control the transmission amount of incident light. Then, a predetermined image is formed in this manner.

The schematic structure of the backlight unit 104 will be described. The backlight unit 104 has a structure in which a diffusion plate 110, a light guide plate 120 and a reflection plate 130 are stacked in this order. These members are supported and fixed by a casing (not shown). The light guide plate 108 is made of a transparent acrylic plate or the like, and a straight tube light source 110 is disposed at one end thereof. Light source 1
As 50, for example, a cathode fluorescent tube can be used.

[0006] Light emitted from the light source 110 is transmitted through the light guide plate 1.
08 and is released from the upper and lower surfaces. Light emitted from the lower surface of the light guide plate 108 is reflected by the reflection plate 110 and returns to the light guide plate 108 again. In addition, the light guide plate 10
The light emitted from the upper surface of the light source 8 is diffused by the diffusion plate 106 and is incident on the liquid crystal panel 102 with reduced luminance unevenness.

Next, the structure of the backlight unit 104 will be described in more detail.

FIG. 3 is an explanatory view of assembling the backlight unit 104 as viewed from the back side. That is, the backlight unit 1
04 is entirely supported by a housing 140. The housing 140 is made of resin and is formed by molding. The diffusion plate 110 and the light guide plate 12
0, the reflection sheet 125 and the reflection plate 130 are stacked in this order. The reflection plate 130 is made of an aluminum plate. These are adhered and fixed to each other by a double-sided tape 115.

On the other hand, a housing for a light source is formed at one end of the housing 140, and the cathode fluorescent tube 150 is connected to the lamp holder 1.
55 and 155 are fixed together. In addition, the cathode fluorescent tube 1
Lead wires 162 and 164 are respectively connected to the electrode portions at both ends of 50. The roots of the lead wires 162 and 164 are
It is fixed by the housing 160. Then, the cover 170 is fixed by the set screws 172.

Here, the lead wires 162 and 164 are inserted and fixed in a groove formed in the housing 140.

[0011]

The liquid crystal display device as described above is required in the market to have a large screen, a small size and light weight, and a further improvement in reliability. Among them, in order to meet the conflicting demands for a large screen and a small size, it is indispensable to narrow the frame portion, that is, the non-display area around the screen display section. For this purpose, it is necessary to make the width of each part of the housing 140 of the backlight part as small as possible.

However, as described above, in the conventional liquid crystal display device, a groove is formed in the housing 140 of the backlight portion so that the lead wire 164 is inserted and fixed.
There is a problem that the width of the housing 140 increases by the thickness of the lead wire 164.

Since the lead wire 164 is a non-light emitting body, it must be shielded from the light source. Therefore, for example, the reflection plate 1
It is conceivable that the liquid crystal display device is disposed on the back surface of the liquid crystal display device 30. However, in this case, the thickness of the liquid crystal display device is increased by the thickness of the lead wire 164.

The present invention has been made in view of such a point. That is, an object of the present invention is to provide a liquid crystal display device that can realize a large screen and a small size with a simple configuration, can simplify a manufacturing process, and can improve reliability.

[0015]

That is, the device according to the present invention comprises a backlight portion and a liquid crystal panel portion, and the backlight portion is a side light in which a lamp as a light source is disposed at an end of a light guide plate. In a liquid crystal display device having a mold configuration, at least a part of a lead wire for supplying power to a lamp is embedded in a casing supporting the lamp.

More specifically, the liquid crystal display device according to the present invention includes a backlight unit and a liquid crystal panel unit, and the backlight unit includes a light guide plate disposed on a back surface of an image display unit of the liquid crystal panel; A lamp as a light source that is disposed at an end of the light guide plate and outside the image display unit and supplies light to the light guide plate, and is formed of a light-shielding resin material; A housing that supports and fixes the light plate and the lamp and covers the lamp, and a lid that is fixed to a part of the housing and holds and fixes the lamp between the housing and the lid; , At least a part of a conducting wire for supplying power to the lamp is embedded therein.

Here, the conductor may be embedded not in the housing but in a lid fixed to the housing and supporting the lamp.

As described above, by embedding the conductive wire in the housing or the lid, the width of the backlight portion can be reduced as compared with the related art by the amount corresponding to the covering of the lead wire. As a result, a large screen and a small size of the liquid crystal display device can be realized, the assembling process can be simplified, and the reliability can be improved.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a compact and large screen by eliminating the coating of the lead wire of a cathode fluorescent tube and the groove for inserting and fixing the lead wire, and embedding the lead wire in the housing of the backlight unit. And simplification of the manufacturing process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1A is a schematic sectional view showing a main part of a light source accommodating portion of a backlight portion of a liquid crystal display device according to the present invention. FIG. 1B is a schematic cross-sectional view of the same portion of the conventional liquid crystal display device shown for comparison.

That is, in the present invention and in the related art, the cathode fluorescent tubes 50, 15
0 and its lamp holders 55, 155
It is held between 140 and lids 70 and 170. However, in the liquid crystal display device according to the present invention shown in FIG. 3A, the conducting wire 64a is embedded in the housing 40 and does not have a separate coating. The housing 40 is a resin molded product, and embedding the conductive wire 64a can be easily realized as so-called “embedding molding”.

On the other hand, in the conventional liquid crystal display device shown in FIG. 1B, the lead wire 164 is constituted by a conductor 164a which is a conductor and a coating 164b which insulates the periphery thereof. 164 is inserted and held in the groove 142 formed in the housing 140.

As is clear from the comparison between FIGS. 1A and 1B, the width of the housing 40 of the backlight portion of the liquid crystal display device according to the present invention is larger than the width of the conventional housing 140 by W. Only small. The width difference W corresponds to the space occupied by the lead wire coating 164b.

As described above, according to the present invention, the covering of the lead wire of the light source is abolished, and the conductor is directly embedded in the housing of the backlight portion. The external shape of the device can be reduced in size. Further, the display screen can be enlarged with the same external dimensions.

On the other hand, in the conventional liquid crystal display device as shown in FIG. 1B, since the lead wire 164 and the housing 140 are separate components, the number of parts is large, and A step of inserting a lead wire into the groove was required. Also, in this lead wire insertion step, assembly errors such as biting of the lead are likely to occur, and the manufacturing yield is easily reduced.

On the other hand, according to the present invention, the conductor 64
a is embedded in the housing 40 to form an integral part. Therefore, the number of parts is reduced and the assembly process is simplified. As a result, according to the present invention, the manufacturing yield can be improved and the manufacturing cost can be reduced.

Further, according to the present invention, the reliability of the liquid crystal display device can be improved. That is, conventionally,
Since the lead wire 164 was inserted and held in the groove of the housing 140, the lead wire 164 sometimes had a slight play. As a result, disconnection or poor contact may occur at the connection end of the lead wire 164 due to excessive mechanical shock or vibration during long-term use of the liquid crystal display device.

On the other hand, according to the present invention, the conductor 64
Since “a” is embedded in the housing 40, there is no movable part due to “play” or the like. As a result, the durability against excessive mechanical shock and vibration is significantly improved. Since liquid crystal display devices are often used in various portable electronic devices, the present invention improves the durability against mechanical shocks and the like more than before so that the liquid crystal display device is more user-friendly. The range of application is further expanded, and the reliability of electronic devices equipped with a liquid crystal display device is also improved.

In the above description, the case where the conducting wire 64a is embedded in the housing 40 of the backlight portion has been described, but the present invention is not limited to this. In addition, the same effect can be obtained by embedding the conducting wire 64a in the lid 70, for example.

In the above description, a liquid crystal display device having only one cathode fluorescent tube in the backlight portion has been described, but the present invention is not limited to this. In addition, for example, a backlight unit having one cathode fluorescent tube on each of the left and right sides of the light guide plate and a liquid crystal display device having a backlight unit having more cathode fluorescent tubes are also available. The present invention can be similarly applied.

[0032]

The present invention is embodied in the form described above, and has the following effects.

First, according to the present invention, the covering of the lead wire of the light source is eliminated and the conducting wire is directly buried in the housing of the backlight part. The outer shape can be reduced. Further, the display screen can be enlarged with the same external dimensions.

Further, according to the present invention, the conductor is embedded in the housing to form an integral part. Therefore, the number of parts is reduced and the assembly process is simplified. As a result, according to the present invention, the manufacturing yield can be improved and the manufacturing cost can be reduced.

Further, according to the present invention, the reliability of the liquid crystal display device can be improved. That is, the conductor 64
Since “a” is embedded in the housing 40, there is no movable part due to “play” or the like. As a result, the durability against excessive mechanical shock and vibration is significantly improved. Since liquid crystal display devices are often used in various portable electronic devices, the present invention improves the durability against mechanical shocks and the like more than before so that the liquid crystal display device is more user-friendly. The range of application is further expanded, and the reliability of electronic devices equipped with a liquid crystal display device is also improved.

That is, according to the present invention, there is provided a liquid crystal display device capable of realizing a large screen and a small size with a simple configuration, simplifying a manufacturing process, and improving reliability. And the industrial benefits are enormous.

[Brief description of the drawings]

FIG. 1A is a schematic cross-sectional view illustrating a main part of a light source accommodating section of a backlight section of a liquid crystal display device according to the present invention.
(B) is a schematic cross-sectional view of the same portion of the conventional liquid crystal display device shown for comparison.

FIG. 2 is a cross-sectional view illustrating a schematic configuration of a liquid crystal display device.

FIG. 3 is an assembly explanatory diagram illustrating a configuration of a backlight unit 104.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 liquid crystal display device 102 liquid crystal panel 104 backlight unit 110 diffusion plate 115 double-sided tape 120 light guide plate 125 reflection sheet 130 reflection plate 140, 40 housing 150, 50 cathode fluorescent tube 155, 55 lamp holder 160 housing 162 lead wire 164 lead wire 164a, 64a Conductor 164b Coating 170, 70 Lid 172 Set screw

Claims (5)

[Claims] A backlight unit and a liquid crystal panel unit, the backlight unit supporting and fixing a lamp as a light source, a light guide plate for guiding light from the lamp, and the lamp and the light guide plate; A liquid crystal display device comprising: a housing serving as a frame of a backlight unit; and at least a part of a lead wire for supplying power to the lamp is embedded in the housing. 2. A liquid crystal display comprising a backlight unit and a liquid crystal panel unit, wherein the backlight unit is disposed on a back surface of the liquid crystal panel, disposed on an end of the light guide plate, and provided with light on the light guide plate. A lamp serving as a light source for supplying light; a housing formed of a light-shielding material and serving as a frame of the backlight unit; and a lamp fixed to a part of the housing and holding the lamp between the housing and the housing. A liquid crystal display device comprising: a lid for fixing; and at least a part of a lead wire for supplying power to the lamp is embedded in the housing. 3. A light guide plate provided on a back surface of an image display unit of the liquid crystal panel, comprising: a backlight unit and a liquid crystal panel unit; A lamp as a light source for supplying light to the light guide plate, which is disposed outside a display unit, and formed of a light-shielding resin material, supporting and fixing the light guide plate and the lamp as a frame of the backlight unit, A liquid crystal display device, comprising: a housing that covers the lamp; at least a part of a conductive wire for supplying power to the lamp is embedded in the housing. 4. A light guide plate provided on a back surface of an image display unit of the liquid crystal panel, comprising: a backlight unit and a liquid crystal panel unit; A lamp as a light source for supplying light to the light guide plate, which is disposed outside a display unit, and formed of a light-shielding resin material, supporting and fixing the light guide plate and the lamp as a frame of the backlight unit, A conductor for supplying power to the lamp, comprising: a housing covering the lamp; and a lid fixed to a part of the housing and holding and fixing the lamp between the housing and the housing. Wherein at least a part of the liquid crystal display device is embedded in the lid. 5. A backlight unit comprising a backlight unit and a liquid crystal panel unit, wherein the backlight unit has a sidelight type configuration in which a lamp as a light source is disposed at an end of a light guide plate, and supplies power to the lamp. A liquid crystal display device, wherein at least a part of a supply wire for supply is embedded in a housing supporting the lamp.