CN1466004A - Liquid crystal display device - Google Patents

Abstract

A liquid crystal display device is provided with a liquid crystal panel, a base, a side reflection mirror, a diffuser and a bottom reflection mirror. In the side reflector, a plurality of lamp holders arranged in a row in a direction parallel to the surface of the liquid crystal panel are provided. These sockets are arranged in such a way that they can respectively hold the low-voltage-side ends of the lamps. A return substrate extending along the arrangement direction of the lamps is mounted on the lamp socket opposite to the liquid crystal panel. In addition, lead wires are drawn from the low-voltage side end of the lamp toward the return substrate, and then passed through the lamp socket and connected to the return substrate. With this structure, it is possible to narrow the frame area.

Description

Liquid crystal display device

field of invention

The invention relates to a liquid crystal display device with a straight backlight component, especially a liquid crystal display device capable of narrowing the picture frame and making the brightness of the liquid crystal panel uniform.

Background technique

Liquid crystal display devices are used to constitute a monitor in a thin TV receiver, a stand-alone display, and a monitor in a notebook-sized personal computer. A conventional liquid crystal display is composed of a backlight unit, a liquid crystal panel, and a housing, wherein the panel allows the light projected from the backlight unit to selectively pass therethrough and form an image thereon, and the housing is used to accommodate the backlight components and LCD panels. As a backlight, there are edge backlight and straight backlight. The feature of edge backlight is that the light source such as fluorescent lamp is placed on the side of the housing, while the feature of straight backlight is that the light source is placed on the opposite side of the liquid crystal panel, and the light is guided to the LCD panel. The straight backlight unit can improve the brightness of the liquid crystal panel compared to the edge backlight light source, and thus can be used to form a monitor in a thin TV receiver, for example, of the high-definition type.

Liquid crystal panel refers to a panel that includes a transparent substrate with switching elements such as TFT (Thin Film Transistor), a transparent counter substrate opposite to the transparent substrate, and liquid crystal sealed between the two substrates. The display part is arranged in a matrix form, wherein a plurality of drivers are respectively connected to a scanning line and a signal line in each liquid crystal display device part, and a connection substrate is connected to each driver. The backlight light source includes a light source such as a fluorescent lamp, a bracket for holding the light source, and a diffuser for diffusing light emitted from the light source.

FIG. 1 is a partial sectional view showing the structure of a conventional liquid crystal display device. As shown in this figure, a conventional liquid crystal display device is provided with a liquid crystal display panel 22 for displaying images, and a frame 21 of an L-shaped member. 22 is supported and constitutes the side part of the entire liquid crystal display device. A frame-shaped spacer 38 is connected to the liquid crystal panel 22 , and the base 23 is connected to the spacer 38 . The gasket 38 is used to prevent the glass substrate of the liquid crystal display panel 22 from being damaged due to contact with the base 23 . Side reflector (side reflector) 24 is connected with base 23. At its end close to the liquid crystal panel 22 , the side mirror 24 supports one side portion of the diffuser 25 . The diffuser 25 is a white translucent plate, for example made of acrylic resin, which is placed parallel to the liquid crystal panel 22 .

A single side reflector 24 has a plurality of lamp sockets 26 arranged in a row in a direction parallel to the surface of the liquid crystal panel 22 . Each socket 26 holds a low-pressure-side end piece 27 of a lamp 27 as a cold-cathode discharge lamp. Several lamps 27 are provided and placed in parallel. The return substrate 28 extending in the direction in which the lamps 27 are arranged is connected to the end member of the lamp holder 26 on the side opposite to the side where the lamps 27 are arranged. The lead wire 29 is drawn out from the low voltage side end part 27a of the lamp 27 along the axial direction of the lamp 27, then passes through the lamp socket 26, reaches the return substrate 28, and is connected to the return substrate 28 through the solder joint 28b formed on the return substrate surface 28a superior. The surface 28 a is perpendicular to the display surface of the liquid crystal panel 22 . The return substrate 28 is interconnected with the lead wire 29 connected to the low-voltage side end piece 27a of the lamp 27.

One end of a single cable (not shown) is connected to the return substrate 28, while the other end is connected to the inverter substrate (not shown), which is connected to the high voltage side end piece (not shown) of the lamp 27 superior. In order to prevent the short circuit caused by the contact between the return substrate 28 and the frame 21, a gap 31 is formed between the return substrate 28 and the frame 21, and an insulating sheet 32 is pasted on the inner surface of the frame 21. Furthermore, a bottom reflector 30 is provided on the opposite side of the diffuser 25 with the lamp 27 therebetween. The bottom mirror 20 serves to reflect light from the lamp 27 toward the liquid crystal panel 22 .

At both ends of each of the lamps 27 as cold cathode discharge tubes, an ineffective light emitting portion 27b is provided, respectively. The part between the ineffective light emitting portions 27b at both ends is the effective light emitting portion 27c. The ineffective light emitting portion 27b of each lamp 27 is a part of a cold cathode discharge tube in which an electrode (not shown) is placed. The ineffective light emitting portion 27b also emits light, but the emitted light is very weak and uneven. Although the length of each ineffective light emitting portion 27b varies depending on the lamp manufacturer, it is generally around 7 mm. As shown in FIG. 1, in this conventional liquid crystal display device, the ineffective light emitting portion 27b is almost covered by the side mirror 24 and the lamp holder 26. As shown in FIG.

In a conventional liquid crystal display device, a frame area 34 where no image is displayed is formed around a display area 33 where an image is displayed through the liquid crystal panel 22 . The frame area 34 is defined by the ineffective light emitting portion 27b, the lamp socket 26, the return substrate 28, the gap 31, and the frame 21 with an insulating sheet 32 attached to its inner surface.

In recent years, for liquid crystal display devices, there has been a need to reduce their size and increase their display area. In order to meet this requirement, it is necessary to form the frame area as narrow as possible. However, as shown in FIG. 1, in conventional liquid crystal display devices, ineffective light emitting portions 27b appear at both ends of each lamp 27, and a lamp holder 26, return substrate 28 and The gap 31, in addition, has an insulating sheet 32 attached to the inner surface of the frame 21. Thus, limitations are encountered in making the frame narrower.

Fig. 2 is a partial sectional view showing the structure of another conventional liquid crystal display device. In the liquid crystal display device shown in FIG. 2, the length of each lamp 27 is set shorter than that of the liquid crystal display panel 22 so that the frame area 34 is as narrow as possible. In addition, the base 23 , the side reflector 24 and the lamp holder 26 used in FIG. 1 are discarded, and a base with a reflector 36 is used instead. Other structures of the conventional liquid crystal display device shown in FIG. 2 are the same as those of the liquid crystal display device shown in FIG. 1 .

However, such a conventional liquid crystal display device shown in FIG. 2 has the following problems. In the liquid crystal display device, the length of each lamp 27 is set shorter than the liquid crystal display panel 22 so as to make the frame area 34 as narrow as possible. As a result, although the frame area 34 of the liquid crystal display device shown in FIG. 2 is narrower than that of the liquid crystal display device shown in FIG. covered so as to protrude between the bases with reflectors 36 . Setting: In FIG. 2, the length of each ineffective light emitting portion 27b protruding from the base with the reflector 36 is A. As a result, when an image is displayed in the display area 33, the effective light-emitting portion 27c of each lamp 27 becomes farther away from the base with the reflector 36 by a distance A, so that a problem arises: the display area The sides of the 33 are partially darkened.

In addition, in the conventional liquid crystal display device shown in FIGS. 1 and 2, the surface 28a of the return substrate 28 is perpendicular to the display surface of the liquid crystal display panel 22. Therefore, when the liquid crystal display device is assembled, the vertical installation including the lamp 27, lamp At the same time as mounting 26 and side reflector 24, solder needs to be applied to return substrate surface 28a so that the axis of lamp 27 becomes vertical. In this way, not only the assembly work is exhausting and the work efficiency is low, but also the assembly work becomes more dangerous.

Summary of the invention

An object of the present invention is to provide a liquid crystal display device having a narrow frame area, which is advantageous in uniform brightness in the display area and easy installation work.

And the liquid crystal display device of the present invention is provided with: a liquid crystal panel, a backlight member, and a frame for accommodating the liquid crystal panel and the backlight member. The backlight unit includes a plurality of cold cathode discharge tubes, lead wires, and a return substrate interconnected with the lead wires, and the lead wires are respectively drawn out directly from one end of the cold cathode discharge tubes in a direction intersecting the longitudinal direction of the tubes, or thereafter, drawn along the longitudinal direction of the pipe. The return substrate is located at a position deviated from an extension line in the longitudinal direction of the cold cathode discharge tube.

Thus, in the present invention, the lead wires are led out from one end face of the tube along a direction intersecting the longitudinal direction of the cold cathode discharge tube, and the return substrate is located at a position deviated from the longitudinal extension of the cold cathode discharge tube. . Thus, the frame area can be narrowed by an amount corresponding to the return substrate. In addition, since the return substrate is not located on the longitudinal extension of the cold cathode discharge tube, a gap for preventing the return substrate from contacting the frame and an insulating sheet are no longer required, thereby making it possible to make the figure The frame area is further narrowed.

In addition, since cold cathode discharge tubes longer than those of the prior art can be used with respect to the size of the liquid crystal display device, the length of the effective light emitting portion of each cold cathode discharge tube can be increased. Therefore, an ineffective light emitting portion in each cold cathode discharge tube can be located between the side mirror and the frame, whereby the uniformity of brightness in the display area of the liquid crystal panel can be improved.

In addition, the solder forming surface of the return substrate can be made parallel to the longitudinal direction of the cold cathode discharge tube, thereby allowing soldering of leads to the return substrate while the cold cathode discharge tube is lying down in an assembly operation of the liquid crystal display device. As a result, it is possible to improve the assembly operation of the liquid crystal display device.

Lead wires may be led out from one end face of the tube along the longitudinal direction of the cold cathode discharge tube, and then bent toward the liquid crystal panel. In this regard, the backlight unit has a bottom reflector on the opposite side of the liquid crystal panel, a cold cathode discharge tube between the liquid crystal panel and the bottom reflector, and a side reflector along one side of the bottom reflector. layout. Return substrates may be located between the side mirrors and the frame.

The lead wire can be drawn out from one end face of the tube along the longitudinal direction of the cold cathode discharge tube, and then bent to the side opposite to the liquid crystal display device. In this regard, the backlight unit may have a holder for accommodating one end of the cold cathode discharge tube, and the return substrate may be mounted on the holder. According to this configuration, the return substrate can be supported by the holder, and it is not necessary to provide any dedicated part for supporting the return substrate.

The cold cathode discharge tube may have electrodes respectively provided outside one end thereof, and lead wires may be respectively connected to the electrodes, and the lead wires may be extended in a direction intersecting the longitudinal direction of the cold cathode discharge tube. In this way, it is possible to prevent a load imposed on the lead wire by bending the lead wire. The return substrate may be an insulating board on which wiring patterns are formed. The return substrate can be made of metal or alloy in the shape of a plate, rod or cable etc. In this way, the return substrate can be formed in any desired shape. As a result, it is possible to smoothly insert the return substrate into the gap between the constituent elements of the liquid crystal display device, or to fit and fix it in such constituent elements.

The bottom reflector may be a metal plate or a white resin plate, or a metal plate or a resin plate having a reflective coating on its surface. In the present invention, the word "metal" is meant to include metals as well as alloys. The "reflector" mentioned in the text refers to a reflective layer made of resin film, paper sheet or vinyl film, etc. Coating refers to a coating or cling layer.

Thus, according to the present invention, it is possible to obtain a liquid crystal display device with a very narrow frame area, which is advantageous in the uniformity of brightness in the display area, and is easy to realize the installation operation.

Brief description of the drawings

Fig. 1 is a partial sectional view, which shows the structure of a conventional liquid crystal display device;

Fig. 2 is a partial sectional view showing the structure of another conventional liquid crystal display device;

3 is a partial sectional view showing the structure of a liquid crystal display device according to a first embodiment of the present invention;

Fig. 4 is an exploded view showing the structure of the liquid crystal display device of the first embodiment;

FIG. 5 is a partial sectional view showing the structure of a liquid crystal display device according to a second embodiment of the present invention; and

Fig. 6 is a partial sectional view showing the structure of a liquid crystal display device according to a modification of the second embodiment.

Detailed Description of the Preferred Embodiment

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. Now, a first embodiment of the present invention will be described. 3 is a partial sectional view showing the structure of a liquid crystal display device according to a first embodiment of the present invention, and FIG. 4 is an exploded view showing the structure of this liquid crystal display device. As shown in FIGS. 3 and 4, in this embodiment of the liquid crystal display device, a liquid crystal panel 2 for displaying images is provided, and a frame 1 of an L-shaped member is provided, and the frame 1 covers the side portion of the surface of the liquid crystal panel and While constituting the side portion of the entire liquid crystal display device, it also supports the liquid crystal panel 2 . A connection substrate 11 (see FIG. 4) for driving the liquid crystal panel 2 is added to the same board. The connection substrate 11 is bent almost at right angles to the liquid crystal display panel 2 and accommodated inside the frame 1 .

A frame-like spacer 18 (see FIG. 4 ) is attached to the liquid crystal panel 2 , and the base 3 is attached to the inner surface of the frame 1 and also to the spacer 18 . The gasket 18 is used to prevent the liquid crystal panel 2 from being damaged due to contact with the base 3 . The side reflector 4 is connected to one side of the base 3, and on the four corners of the base 3, on the side where the side reflector 4 is provided, fixing pieces 19 are respectively provided. A light sheet 12 for converging the transmitted light and a diffuser 5 for diffusing the transmitted light are placed between the base 3 and the side mirror 4 . The light sheet 12 and the diffuser 5 are supported by the base 3 , the side mirror 4 and the fixing 19 . The light sheet 12 and the diffuser 5 can be, for example, translucent white sheets made of acrylic resin, and can be stacked parallel to the liquid crystal panel 2 in sequence. The light sheet 12 is placed closer to the liquid crystal panel 2 than the diffuser 5 .

The side reflector 4 is provided with a plurality of lamp sockets 6 arranged in a row in a direction parallel to the surface of the liquid crystal panel 2 . Each lamp holder 6 holds the low-voltage-side end 7a of a lamp 7 serving as a cold-cathode discharge tube. Several lamps 7 are provided, and these lamps are arranged in parallel. On its side opposite to the liquid crystal panel 2 , a return substrate 8 extending in the arrangement direction of the lamps 7 is connected to the lamp holder 6 . The return substrate 8 includes an insulating substrate and wiring patterns formed thereon. However, the return substrate 8 is not what is called a circuit substrate on which elements such as transistors are printed. The lead wire 9 first protrudes from the low-voltage side end 7a along the axis of the lamp 7, and then bends toward the return substrate 8, passes through the lamp holder 6 and then reaches the return substrate 8, and is connected to one formed on the return substrate 8. On the solder joint 8b on the surface 8a, wherein the surface 8a is opposite to the liquid crystal panel 2. In this way, the low-voltage side end portions 7 a of the lamps 7 are connected to each other via the return substrate 8 .

Ineffective light emitting portions 7b are respectively provided at both ends of each lamp 7 which is a cold cathode discharge tube. A portion between the ineffective light emitting parts 7b at both ends is an effective light emitting part 7c. The ineffective light emitting portion 7b of each lamp 7 is a portion in which electrodes are placed in the cold cathode discharge tube. The ineffective light emitting portion 7b located on the side of the side mirror 4 is hidden from the outside of the side mirror 4 . In this embodiment of the liquid crystal display device, a picture frame area 14 that does not display an image is formed around the display area 13, and the display area displays an image on the image display surface of the liquid crystal display device through the liquid crystal panel 2. , the ineffective light emitting portion 7b of the lamp 7 and the lamp holder 6 are located within the frame area 14 . The bottom reflector 10 is located on the side opposite to the liquid crystal panel 2 when viewed from the lamp 7 side. The bottom mirror 10, which reflects the light from the lamp 7 toward the liquid crystal display panel 2, is made of a metal member having a high light reflection coefficient, or is formed by coating or pasting a reflective material such as white resin on aluminum or Formed on metals such as aluminum alloys. The surface of the central portion of the bottom reflector 10 and its adjoining portion is parallel to the axial direction of the lamp 7 and also parallel to the surfaces of the diffuser 5 , the light sheet 12 and the liquid crystal panel 2 . Three side portions of the bottom mirror 10 that are not in contact with the side mirror 4 are bent obliquely so as to surround the lamp 7 while also surrounding the side mirror 4 .

As shown in Figure 4, one end of the cable 15 is connected to the return substrate 8, and at the same time, the other end on the opposite side is connected to the inverter substrate 17, and the inverter substrate 17 is connected to the high voltage terminal 7d located at the lamp 7 The electrode part (not shown) on the high voltage side. Using screws 29, the bottom reflector 10 is fixed to the frame 1, whereby frame 1, liquid crystal panel 2, base 3, side reflector 4, light sheet 12, diffuser 5, lamp 7, lamp holder 6, bottom The reflector 10, the cable 15 and the inverter substrate 17 are all integrally mounted together to constitute a liquid crystal display device.

Now, the operation of the liquid crystal display device of this embodiment will be described. When the voltage of 10 to 24 V is supplied to the inverter substrate 17 by an external power source (not shown), the inverter substrate 17 boosts this voltage to the 500 to 1000 V and supplies it to the The high-voltage side electrode portion of the high-voltage side end 7d of the lamp 7 makes the lamp 7 emit light. The light emitted by the lamp 7 is transmitted directly to the diffuser 5, or after being reflected by the bottom reflector 10 or the side reflector 4, passes through the diffuser 5 to be diffused, and then passes through the light sheet 12 and condensed by it, the condensed light is fed to the liquid crystal panel 2 . The liquid crystal panel 2 driven by the connection plate 11 allows the light fed from the light sheet 12 to pass selectively and generate colors to form an image in the display area 13 of the liquid crystal panel 2 .

In this embodiment of the liquid crystal display device, the lead wire 9 is led from the low voltage side end 7a of the lamp 7 to the liquid crystal panel 2, and the return substrate 8 is placed on the lamp holder 6 on the opposite side of the liquid crystal panel 2 thereof. Therefore, unlike conventional liquid crystal display devices, in this embodiment of the liquid crystal display device, there is neither a return substrate nor an insulating sheet between the lamp holder 6 and the frame 1 (see FIG. 1 ). As a result, compared with the conventional liquid crystal display device, in this embodiment of the liquid crystal display device, the frame area 14 can be narrowed by an amount corresponding to the return substrate 28 and the insulating sheet 32, as shown by FIG. As can be seen from the comparison between the frame area 34 in the conventional liquid crystal display device and the frame area 14 shown in FIG. 3 . In this embodiment, the frame area 14 can be made narrower by about 2 mm compared to conventional liquid crystal display devices. At present, in liquid crystal display devices, reducing the volume and increasing the screen size are very important goals to be achieved. Therefore, the picture frame area 14 can be made narrower by about 2 mm than in the prior art, which is a very excellent effect.

Besides, unlike the conventional liquid crystal display device shown in FIG. 2, this embodiment does not need to shorten the lamp 7 in order to narrow the frame area 14. Therefore, as can be seen by comparing the length A in the conventional liquid crystal display device shown in FIG. 2 with the length A in the liquid crystal display device of this embodiment shown in FIG. 3, the ineffective light of the lamp 7 Most of the emitting portion 7b can be covered by the side reflector 4, thereby making the brightness of the liquid crystal display panel 2 uniform.

Alternatively, it is also possible to make the lamp 7 longer than that of a conventional liquid crystal display device while making the width of the frame area 14 almost the same as that in a conventional liquid crystal display device. In this way, the ineffective light emitting portion 7b of the lamp 7 can be completely covered by the side reflector 4 . That is, the length A shown in FIG. 3 may be set to zero. As a result, the brightness of the liquid crystal panel 2 can be made more uniform. Thus, in this embodiment, the frame can be narrowed at a high level while obtaining uniformity of brightness at a high level.

Furthermore, in this embodiment, the solder-formed face 8 a of the return substrate 8 is parallel to the bottom mirror 10 . Therefore, when assembling the liquid crystal display device, the liquid crystal display device can be placed on the workbench so that the bottom mirror 10 becomes parallel to the upper surface of the workbench, and welding can be performed in this state. Therefore, not only the assembly work is made easier, the work efficiency is improved, but also the safety is improved.

The lamp holder 6 can be brought into contact with the inner surface of the frame 1, thereby not only it is possible to eliminate the gap between the lamp holder 6 and the frame 1, thereby making the picture frame area 14 narrower, but it is also possible to improve the overall liquid crystal display. device stiffness. The bottom reflector 10 used in this embodiment is made of a metal member having a high light reflection coefficient, or is formed by applying a white resin to a metal sheet such as aluminum or an aluminum alloy sheet. . However, this does not constitute a limitation of the present invention. For example, the bottom mirror may be formed of white resin, or of a metal sheet such as a mirror surface having a high reflectance. A highly reflective reflective material such as paper or vinyl can be formed inside (reflective surface side) of the bottom mirror by coating or pasting. Furthermore, although it is formed on the return substrate 8 used in this embodiment by forming a wiring pattern on an insulating substrate, the return substrate is not limited to this structure. For example, the return substrate may be in the shape of a sheet, rod or cable formed of metal or alloy.

Next, a second embodiment of the present invention will be described. Fig. 5 is a partial sectional view showing the structure of a liquid crystal display device according to a second embodiment of the present invention. In this embodiment of the liquid crystal display device, a lamp holder 16 supporting the low-voltage side end 7a of the lamp 7 and a lead wire 9 are provided, which lead from the low-voltage side end 7a of the lamp 7 first along the longitudinal direction of the lamp 7 Extend out, and then draw out along the direction away from the liquid crystal panel 2. The return substrate 8 is connected to the lamp socket 16 by its side farther away from the liquid crystal panel 2 . The lead wire 9 is led out from the low-voltage side end 7a of the lamp 7, passes through the interior of the lamp socket 16, and is connected to a solder joint 8b formed on the surface 8a of the return substrate 8. In this embodiment of the liquid crystal display device, a base with a reflector 20 having the overall shape of the base 3 and side reflector 4 used in the previous first embodiment is provided instead of the base 3 and the side reflector 4 . Also, in this embodiment of the liquid crystal display device, the use of light sheets is omitted. The other structures and effective points in this embodiment are the same as those of the liquid crystal display device in the first embodiment.

Also in this embodiment of the liquid crystal display device, the same effects as in the previous first embodiment are obtained. That is, the frame area 14 of the liquid crystal display device in this embodiment can be narrowed by a amount corresponding to the return substrate 28 and the insulating sheet 32 (see FIG. 1 ) used in the conventional liquid crystal display device, as shown in FIG. 1 As can be seen from the comparison between the frame area 34 in the conventional liquid crystal display device shown in FIG. 5 and the frame area 14 in the liquid crystal display device in this embodiment shown in FIG. 5 . In addition, since most of the ineffective light emitting portion 7b of the lamp 7 is covered by the base having the reflective mirror 20, it is possible to ensure uniform brightness of the liquid crystal panel 2, as can be obtained from the conventional liquid crystal display device of FIG. As can be seen from the comparison between the length A of , and the length A in the liquid crystal display device of this embodiment shown in FIG. 5 .

In addition to the above-mentioned effects, this embodiment brings the following effects. Since the welding spot 8b on the return substrate 8 is exposed on the back side of the liquid crystal display device, that is, the side where the liquid crystal panel 2 is not provided, even if the liquid crystal panel 2, the diffuser 5, and the mirror 20 are provided by the frame 1 After the base, lamp holder 16, lamp 7 and bottom reflector 10 are combined into one, welding can still be carried out. Therefore, the working efficiency in assembling the liquid crystal display device is further improved. In addition, since the functions of the base 3 and the side reflector 4 (see FIG. 3 ) used in the first embodiment are replaced by the base with the reflector 20, it is possible to reduce the number of used mirrors compared with the first embodiment. number of devices.

Although in this embodiment, the return substrate 8 is attached to the lamp holder 16, it may also be mounted on the bottom reflector 10 on its side where the lamp 7 is not placed.

Now, a modification of this embodiment will be described. Fig. 6 is a partial sectional view showing the structure of a liquid crystal display device according to this modification. In this modification, a metal external electrode 35 is formed on the low-voltage side end portion 7 a of the lamp 7 , and the lead wire 9 is led from the external electrode 35 to the return substrate 8 . The other configurations and effective points of the liquid crystal display device according to this modification are the same as those of the previous liquid crystal display device of the second embodiment. In the above-mentioned first and second embodiments, the lead wire 9 first protrudes from the low-voltage side end 7a of the lamp 7 along the axial direction of the lamp 7, and then bends toward the return substrate 8, so that the lead wire 9 is applied some kind of burden. On the other hand, in this modification, since the external electrodes are provided, such a burden can be eliminated. Therefore, it is possible to improve the reliability of the liquid crystal display device.

Claims (10)

1. liquid crystal display device comprises:

Liquid crystal board;

Part backlight, described back light part branch comprises:

Some cold cathode discharge tubes;

Directly along the direction that intersects with described pipe longitudinal direction respectively from a lead-in wire that end face is drawn of described cold cathode discharge tube, or afterwards, the lead-in wire of vertically drawing from pipe; And

Return substrate, it and described lead-in wire are connected to each other, and are positioned on the position of the longitudinal direction extended line that departs from described cold cathode discharge tube; And

Frame is used for fixing described liquid crystal board and described part backlight.

2. according to the liquid crystal display device of claim 1, it is characterized in that, described lead-in wire by along the longitudinal direction of described cold cathode discharge tube after an end face of pipe is drawn, bent towards described liquid crystal board.

3. according to the liquid crystal display device of claim 1, it is characterized in that, described lead-in wire by along the longitudinal direction of described cold cathode discharge tube after an end face of pipe is drawn, bent towards a side opposite with described liquid crystal board.

4. according to the liquid crystal display device of claim 1, it is characterized in that the described substrate that returns forms by form wiring pattern on an insulated substrate, also can be the shape for plate, bar or the cable that is formed by metal or alloy.

5. according to the liquid crystal display device of claim 1, it is characterized in that described part backlight also comprises:

Bottom viewfinder on described liquid crystal board opposite, has described cold cathode discharge tube between the two; And

Described reflective mirror is placed on the lateral edges of described bottom viewfinder.

6. according to the liquid crystal display device of claim 5, it is characterized in that described reflection substrate is placed between described side reflective mirror and the described frame.

7. according to a kind of liquid crystal display device of claim 1, it is characterized in that described part backlight also comprises supports seat, is used for fixing an end of described cold cathode discharge tube, the described substrate that returns is installed on the described support seat.

8. according to a kind of liquid crystal display device of claim 1, it is characterized in that described cold cathode discharge tube, outside at an one end face, be respectively equipped with electrode, described lead-in wire is connected respectively to described electrode, and extends along the direction that the longitudinal direction with cold cathode discharge tube intersects.

9. according to a kind of liquid crystal display device of claim 5, it is characterized in that each described cold cathode discharge tube all comprises:

Invalid smooth radiating portion is formed at two ends longitudinally respectively, and between described side reflective mirror and described frame; And

Effective light radiating portion is between two invalid smooth radiating portions.

10. according to a kind of liquid crystal display device of claim 5, it is characterized in that described bottom viewfinder is made of sheet metal or white resin sheet, or be covered with by its surface that a kind of metal of reflecting material or resin sheet constitute.

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