JP2000019509A - Liquid crystal display - Google Patents

Abstract

(57) [Summary] [Problem] To suppress the occurrence of color unevenness due to heat. SOLUTION: The liquid crystal display monitor comprises a support base and a liquid crystal display monitor supported by the support base, and the liquid crystal display monitor has a liquid crystal display panel inside its outer frame and a liquid crystal display panel on the back of the liquid crystal display panel. A backlight unit to be disposed, the backlight unit comprising a plurality of cathode ray tubes arranged side by side facing the liquid crystal display panel, and a reflecting plate for guiding light from the cathode ray tube to the liquid crystal display panel side. In addition to the above, a cooling fan is provided on the outer frame, and the cooling fan is arranged at a position overlapping with an electrode of the cathode ray tube.

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, and more particularly to a liquid crystal display called a so-called liquid crystal display monitor.

[0002]

2. Description of the Related Art Since a so-called liquid crystal display monitor itself has a panel shape, it is configured with a support base and is used by being placed on a desk or the like.

[0003] The liquid crystal display monitor includes a liquid crystal display panel, a backlight unit disposed on the back of the liquid crystal display panel, and the like, which are built in a resin case as an outer frame.

In a liquid crystal display panel, transparent substrates disposed opposite to each other with a liquid crystal interposed therebetween are used as envelopes so as to control the light transmittance of the liquid crystal in a large number of pixel regions formed in the spreading direction of the liquid crystal. It is configured.

For this reason, a liquid crystal display panel is usually used with a backlight unit disposed on the back surface thereof.

[0006]

In a liquid crystal display device having such a structure, a backlight unit has been increased in size with the recent increase in size of a liquid crystal display panel (for example, a size of 18 inches). From the viewpoint of efficiency, the use of a so-called direct type is preferred.

Here, the direct-type backlight unit is composed of a plurality of cathode ray tubes arranged side by side facing the liquid crystal display panel and a reflector for guiding light from the cathode ray tube to the liquid crystal display panel side. Have been.

However, it has been pointed out that this backlight unit requires, for example, about eight cold cathode ray tubes, and the adverse effect of heat generation due to the cold cathode ray tube cannot be ignored.

The reason is that the liquid crystal in the liquid crystal display panel causes color unevenness due to the heat from the cathode ray tube.

The present invention has been made under such circumstances, and an object of the present invention is to provide a liquid crystal display device capable of suppressing the occurrence of color unevenness due to heat.

[0011]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the liquid crystal display monitor comprises a support base and a liquid crystal display monitor supported by the support base. The liquid crystal display monitor has a liquid crystal display panel and a back surface of the liquid crystal display panel in its outer frame. And a plurality of cathode ray tubes arranged side by side facing the liquid crystal display panel, and a reflector for guiding light from the cathode ray tube to the liquid crystal display panel side. And a cooling fan is provided on the outer frame,
The cooling fan is disposed at a position overlapping with the electrode of the cathode ray tube.

In the liquid crystal display device thus configured, since the heat generated from the cathode ray tube is cooled by the cooling fan, the heat does not adversely affect the liquid crystal in the liquid crystal display panel.

In this case, the cooling effect is improved by disposing the cooling fan at a position overlapping the electrode part of the cathode ray tube.

Since the cathode ray tube generates a large amount of heat at its electrode portion, if a cooling fan is mounted so as to be close to this portion, the cooling fan need not be mounted at other portions. .

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the liquid crystal display device according to the present invention will be described below with reference to the drawings. Embodiment 1 FIG. [Equivalent Circuit of Liquid Crystal Display] FIG. 1 is an equivalent circuit diagram showing an embodiment of the liquid crystal display according to the present invention. The figure shows
Although it is a circuit diagram, it is drawn corresponding to an actual geometric arrangement.

In this embodiment, the present invention is applied to a liquid crystal display device employing a so-called in-plane switching method known as having a wide viewing angle.

First, there is a liquid crystal display panel 1, and the liquid crystal display panel 1 has transparent substrates 1A and 1B opposed to each other via a liquid crystal as an envelope. In this case, one transparent substrate (lower substrate in the figure: matrix substrate 1A)
Is formed slightly larger than the other transparent substrate (upper substrate in the drawing: color filter substrate 1B), and the lower and right peripheral edges in the drawing are arranged substantially flush.

As a result, the periphery of one transparent substrate 1A on the left side in the figure and the periphery on the upper side in the figure extend outward with respect to the other base transparent plate 1B. As will be described later in detail, this portion is a region where the gate drive circuit and the drain drive circuit are mounted.

Pixels 2 arranged in a matrix are formed in a region where the transparent substrates 1A and 1B overlap each other. The pixels 2 are scanning signal lines extending in the x direction in FIG. A switching element TFT formed in a region surrounded by a scanning signal line 3 and a video signal line 4 extending in the y direction and juxtaposed in the x direction; This switching element TF
And a pixel electrode to which a video signal supplied from one video signal line 4 via T is applied.

Here, as described above, each pixel 2
It employs a so-called lateral electric field system, and includes a counter electrode and an additional capacitance element in addition to the switching element TFT and the pixel electrode, as described in detail later.

Each scanning signal line 3 has one end (the left end in the figure) extending outside the transparent substrate 1B, and is connected to an output terminal of a gate drive circuit (IC) 5 mounted on the transparent substrate 1A. It is to be connected.

In this case, a plurality of gate driving circuits 5 are provided, and the scanning signal lines 3 are grouped together adjacent to each other. Each is connected to the circuit 5.

Similarly, one end (upper end in the drawing) of each video signal line 4 extends to outside the transparent substrate 1B.
Drain drive circuit (IC) 6 mounted on transparent substrate 1A
Output terminal.

In this case as well, a plurality of drain driving circuits 6 are provided, and the video signal lines 4 are grouped together adjacent to each other, and each of the grouped video signal lines 4 Each is connected to the drive circuit 6.

On the other hand, there is a printed circuit board 10 (control board 10) which is arranged close to the liquid crystal display panel 1 on which the gate drive circuit 5 and the drain drive circuit 6 are mounted. Circuit 11
And a control circuit 12 for supplying an input signal to the gate drive circuit 5 and the drain drive circuit 6.
Is installed.

The signal from the control circuit 12 is supplied to the gate drive circuit 5 and the drain drive circuit 6 via the flexible wiring board (gate circuit board 15, drain circuit board 16A, drain circuit board 16B). Has become.

That is, on the gate drive circuit 5 side, a flexible wiring board (gate circuit board 15) having terminals connected to the input-side terminals of the respective gate drive circuits 5 is disposed.

The gate circuit board 15 is formed such that a part thereof extends to the control board 10 side.
Connected through.

The output signal from the control circuit 12 mounted on the control board 10 is supplied to each gate drive circuit via the wiring layer on the control board 10, the connection section 18, and the wiring layer on the gate circuit board 15. 5 is input.

On the drain drive circuit 6 side, drain circuit boards 16A, 16A, 1B having terminals connected to the input side terminals of these drain drive circuits 6, respectively, are provided.
6B are arranged.

The drain circuit boards 16A and 16B are
A part thereof is formed to extend to the control board 10 side, and the control board 10
And the connection portions 19A and 19B.

The output signal from the control circuit 12 mounted on the control board 10 is transmitted through the wiring layer on the control board 10, the connecting portions 19A and 19B, and the wiring layers on the drain circuit boards 16A and 16B. The signals are input to the respective drain drive circuits 16A and 16B.

The drain circuit boards 16A and 16B on the side of the drain drive circuit 6 are provided in two parts as shown in the figure. This is for example, in order to prevent adverse effects due to thermal expansion due to an increase in the length of the drain circuit board in the x direction in the figure as the size of the liquid crystal display panel 1 increases.

The output from the control circuit 12 on the control board 10 is supplied to the drain circuit board 16A.
Are connected to the corresponding drain drive circuit 6 via the connection portion 19A of the drain circuit board 16B and the connection portion 19A of the drain circuit board 16B.

Further, a video signal is supplied from the video signal source 22 to the control board 10 via the interface board 24 by the cable 23 and is input to the control circuit 12 mounted on the control board 10. I have.

In this figure, the liquid crystal display panel 1, the gate circuit board 15, the drain circuit boards 16A and 16B,
Although the control board 10 and the control board 10 are drawn so as to be positioned substantially in the same plane, the control board 10 is actually a gate circuit board 15 and a drain circuit board 1.
It is bent at the portions 6A and 16B and positioned so as to be substantially perpendicular to the liquid crystal display panel 1.

This is for the purpose of reducing the so-called frame area. Here, the frame refers to a region between the outline of the outer frame of the liquid crystal display device and the outline of the display unit. By reducing this region, an effect of increasing the area of the display unit with respect to the outer frame is obtained. be able to.

[Module of Liquid Crystal Display] FIG. 2 is an exploded perspective view showing an embodiment of the module of the liquid crystal display according to the present invention.

The liquid crystal display device shown in the figure is roughly divided into a liquid crystal display panel module 400 and a backlight unit 30.
0, resin frame 500, middle frame 700, upper frame 8
00, etc., which are modularized. Hereinafter, these members will be sequentially described.

[Liquid Crystal Display Panel Module] The liquid crystal display panel module 400 includes a liquid crystal display panel 1 and a plurality of semiconductors I mounted around the liquid crystal display panel 1.
C, a gate drive IC 5 and a drain drive IC 6, and flexible gate circuit boards 15 and drain circuit boards 16 (1
6A, 16B).

That is, the output from the control board 10 described later is input to the gate drive IC 5 and the drain drive IC 6 on the liquid crystal display panel 100 via the gate circuit board 15 and the drain circuit boards 16A and 16B.
The output of each drive IC is input to the scanning signal line 2 and the video signal line 3 of the liquid crystal display panel 1.

Here, as described above, the liquid crystal display panel 1 has a display area composed of a number of pixels arranged in a matrix, and one of the pixels is configured as shown in FIG. Has become.

In the figure, a scanning signal line 3 and a counter voltage signal line 50 extending in the x direction are formed on the main surface of a matrix substrate 1A. Then, a region surrounded by each of the signal lines 3 and 50 and a video signal line 2 extending in the y direction described later is formed as a pixel region.

That is, in this embodiment, the scanning signal line 3
And the counter voltage signal line 50 is formed by running, and a pixel region is formed in each of the ± y directions with the counter voltage signal line 50 as a boundary.

By doing so, the number of the counter voltage signal lines 50 arranged in parallel in the y direction can be reduced to about half of the conventional voltage signal line, whereby the closed area can be shared with the pixel area side. As a result, the area of the pixel region can be increased.

In each pixel region, the counter voltage signal line 50 is formed with counter electrodes 50A extending in the y direction integrally therewith, for example, at three intervals. Each of these counter electrodes 50A extends close to each other without being connected to the scanning signal line 3, two of which are arranged adjacent to the video signal line 3, and the other one is positioned at the center. Have been.

Further, the main surface of the transparent substrate 1A on which the scanning signal lines 3, the counter voltage signal lines 50, and the counter electrodes 50A are formed is covered with the scanning signal lines 3 and the like, for example, by a silicon nitride film. Is formed. This insulating film serves as an interlayer insulating film for insulating the video signal line 2 to be described later from the scanning signal line 3 and the counter voltage signal line 50, as a gate insulating film for the thin film transistor TFT, and a storage capacitor Cstg. Function as a dielectric film.

On the surface of this insulating film, first, a semiconductor layer 51 is formed in a region where the thin film transistor TFT is formed. The semiconductor layer 51 is made of, for example, amorphous Si, and is formed on the scanning signal line 3 so as to overlap with a portion adjacent to the video signal line 2 described later. Thus, a part of the scanning signal line 3 also serves as a gate electrode of the thin film transistor TFT.

The video signal lines 2 extending in the y direction and juxtaposed in the x direction are formed on the surface of the insulating film. This video signal line 2 is connected to a thin film transistor TF
A drain electrode 2A extending to a part of the surface of the semiconductor layer 51 constituting T is integrally provided.

Further, a pixel electrode 53 connected to the source electrode 53A of the thin film transistor TFT is formed on the surface of the insulating film in the pixel region. This pixel electrode 53
Are formed so that the center of each of the opposed electrodes 50A extends in the y direction. That is, one end of the pixel electrode 53 also serves as the source electrode 53A of the thin film transistor TFT, extends in the y direction as it is, extends over the counter voltage signal line 50 in the x direction, and then extends in the y direction. It is shaped like a letter.

Here, the counter voltage signal line 5 of the pixel electrode 53
The portion superimposed on 0 constitutes a storage capacitor Cstg between the counter voltage signal line 50 and the insulating film as a dielectric film. The storage capacitance Cstg has an effect of storing video information in the pixel electrode 53 for a long time when the thin film transistor TFT is turned off, for example.

The surface of the semiconductor layer 51 corresponding to the interface between the drain electrode 2A and the source electrode 53A of the thin-film transistor TFT is doped with phosphorus (P) to form a high concentration layer. Ohmic contact at the electrode is achieved. In this case, the high concentration layer is formed over the entire surface of the semiconductor layer 51,
After each of the electrodes is formed, the above structure can be obtained by etching the high-concentration layer other than the electrode formation region using the electrodes as a mask.

Then, as described above, the thin film transistor TF
T, video signal line 2, pixel electrode 53, and storage capacitor Cs
A protective film made of, for example, a silicon nitride film is formed on the upper surface of the insulating film on which the tg is formed, and an alignment film is formed on the upper surface of the protective film to form a so-called lower substrate of the liquid crystal display panel 1. I have.

Although not shown, a portion of the transparent substrate (color filter substrate) 1B, which is a so-called upper substrate, on the liquid crystal side has a black matrix (FIG. 3) having an opening at a portion corresponding to each pixel region. (Corresponding to code 54)
Are formed.

Further, a color filter is formed so as to cover an opening formed in a portion corresponding to the pixel area of the black matrix 54. This color filter has a different color from that in the pixel region adjacent in the x direction, and each has a black matrix 54.
It has a border at the top.

Further, as described above, a black matrix,
A flat film made of a resin film or the like is formed on the surface on which the color filters are formed, and an alignment film is formed on the surface of the flat film.

[Backlight] A backlight unit 300 is arranged on the back of the liquid crystal display panel module 400.

The backlight unit 300 is of a so-called direct type, and a plurality (eight in the figure) of cold cathode lines extending in the x direction and juxtaposed in the y direction in FIG. It comprises a tube 35 and a reflector 36 for irradiating the light from the cold cathode ray tube 35 to the liquid crystal display panel module 400 side.

The reflecting plate 36 is, for example, a cold cathode ray tube 3
5 are formed in a wave shape in the juxtaposition direction (y direction). That is, each cold cathode ray tube 35 has an arcuate concave portion at a place where the cold cathode ray tube 35 is disposed, and has a shape having a sharp convex portion between each cold cathode ray tube. It is an efficient shape to irradiate the display panel module side.

[Resin Frame] The resin frame 500 constitutes a part of an outer frame of a modularized liquid crystal display device, and accommodates the backlight unit 300.

Here, the resin frame 500 has a box shape having a bottom surface and side surfaces, and a diffusion plate (not shown) disposed over the backlight unit 300 can be placed on the upper end surface of the side surface. It has become.

This diffusion plate is used for the backlight unit 300.
Having a function of diffusing light from each cold cathode ray tube 35,
Thereby, it is possible to irradiate the liquid crystal display panel module 400 side with uniform light without uneven brightness.

In this case, the resin frame 500 has a relatively small thickness. This is because the decrease in mechanical strength can be reinforced by the middle frame 700 described later.

The DC / AC inverter board 40, which is one of the power supply circuits 11, is mounted on the back of the resin frame 500.

The DC / AC inverter board 40 constitutes a part of a power supply for supplying power to each of the cold cathode ray tubes 35 of the backlight unit 300.
The connection from the inverter board 40 is connected to terminals at both ends of each cold cathode ray tube 35.

FIG. 4 is a view of the resin frame 500 viewed from its back surface, that is, the surface opposite to the side on which the backlight unit 300 is disposed.

As is apparent from FIG.
0 is formed with a protrusion 500A in which each side parallel to the x direction protrudes along each side.

That is, the resin frame 500 has a side surface portion 50 in which a pair of sides (each side parallel to the x direction) corresponding to the outer shape viewed from the viewing side of the liquid crystal display device extend to the back side.
0B.

The reason for this construction is that the resin frame 50
0 also has the effect of giving strength to twisting due to the opposite rotational force on its diagonal, but the strength of the housing composed of a combination of this resin frame 500 and a later-described middle frame 700 is reduced. By making it sufficient.

The side portion 500 of the resin frame 500
The height of B is DC / A, as will be apparent from the following description.
The height is made higher than the height of the C inverter board 40, so that it is relatively large. However, this side portion 50
0B, as described above, is opposed to the control board 10 (actually via the middle frame 700).
Are arranged close to each other.

Therefore, there is an effect that the control board 10 having a complicated circuit configuration can be configured to be large.

In this case, the control board 10
Since the middle frame 700 exists between the liquid crystal display panel module 400 and the liquid crystal display panel module 400, an effect of having a function of shielding electromagnetic waves is also achieved.

In this embodiment, the protrusion 500
A is provided on each side parallel to the x direction, but is not limited to this. Needless to say, the same effect can be obtained even if provided on each side parallel to the y direction. .

[DC / AC Inverter Board] FIG. 5 is a view showing the DC / AC inverter board 40 disposed on the back surface of the resin frame 500.

The DC / AC inverter board 40 includes
Transformers 71 corresponding to the number of cold cathode ray tubes 35 of the backlight unit 300 (eight in this embodiment) are mounted, and each of these transformers 71 is connected to one end side (high voltage side) of each cold cathode ray tube 35. They are arranged so as to substantially overlap.

This is because, when power is supplied to each cold cathode ray tube 35, the length of the wiring can be made as short as possible.

The DC / AC inverter substrate 40
Are arranged via a shield plate 72 made of metal and attached to the back surface of the resin frame 500. A part of the shield plate 72 (the DC / AC inverter board 4
An opening 72A is provided in the “mounting portion of the“ 0 ”).
This is to avoid generating an eddy current in the shield plate 72 by the transformer 71.

Then, the DC /
The AC inverter board 40, including its mounted components,
The height is such that it does not protrude from the protrusion 500B of the resin frame 500.

In other words, the protrusion 50 of the resin frame 500
0B is a DC / AC inverter board 40 including mounted components.
Is set high enough not to protrude.

[Middle Frame] A middle frame 700 is arranged between the liquid crystal display panel module 400 and the diffusion plate.

The middle frame 700 has an opening 42 at a portion corresponding to the display area of the liquid crystal display panel module 400.
Is formed from a relatively thin metal plate on which is formed.

The middle frame 700 has a function of pressing the diffusion plate against the resin frame 500 and a function of mounting the liquid crystal display panel module 400.

Therefore, the liquid crystal display panel module 40
A spacer 44 for positioning the liquid crystal display panel 100 is attached to a part of the upper surface of the middle frame 700 on which 0 is placed. Thereby, the liquid crystal display panel 10
“0” enables accurate positioning with respect to the middle frame 700.

Then, the side face 4 is attached to the middle frame 700.
6 has an integrally formed shape, in other words, a shape in which the opening 42 is formed on the bottom surface of a substantially box-shaped metal plate.

[0086] The middle frame 700 having such a shape is formed by the resin frame 50 with the diffusion plate 600 interposed therebetween.
0 is fitted. In other words, the middle frame 700 is attached to the side surface 46 with respect to the resin frame 500.
Are mounted so that the inner wall faces the outer wall on the side surface of the resin frame 500.

The middle frame 700 of the metal plate configured as described above, together with the resin frame 500, forms one frame (housing).
Therefore, the mechanical strength of the resin frame 500 can be improved without increasing its thickness.

That is, even if the middle frame 700 and the resin frame 500 do not have sufficient mechanical strength, they are fitted together as described above to improve the mechanical strength. It becomes resistant to twisting around the diagonal of the body.

The protrusions 500A formed on the resin frame 500 also increase the strength against twisting around the diagonal line of the box.

Therefore, there is an effect that a sufficient strength can be secured without increasing the so-called frame in the module of the liquid crystal display device.

Also, the middle frame 700 itself has an effect that the mechanical strength is increased as compared with a substantially planar one having no side surface, and the handling in the stage before assembly of the module is facilitated.

In this embodiment, the middle frame 700
Control board 10 and DC / DC
The converter board 11 and the converter board 11 are arranged to face each other. In other words, the frame is arranged perpendicular to the liquid crystal display panel module 400, thereby reducing the size of the frame.

In this case, the control board 10 comprises a flexible gate circuit board 15 and a drain circuit board 16 attached to the liquid crystal display panel module 400.
A and 16B are connected via connection portions 18, 19A and 19B, respectively, and the above-described arrangement is obtained by bending the drain substrate 31.

As described above, the influence of the electromagnetic waves generated from the control board 10 on other members can be avoided by the side surface 46 of the middle frame 700 as described above.

In the above-described embodiment, the box-shaped middle frame 700 has been described. However, the middle frame 700 does not need to be completely box-shaped, and may have a side surface formed on at least one side. Good.

[0096] This is because such a middle frame 700 is not planar but has a bent portion, and thereby has a structure in which mechanical strength is improved.

[Upper Frame] This upper frame 800
Liquid crystal display panel module 400, middle frame 700,
In addition to having a function of pressing the diffusion plate toward the resin frame 500, the resin frame 500 and the resin frame 500 constitute an outer frame of the module of the liquid crystal display device.

The upper frame 500 has an opening (display window) 48 at a portion corresponding to the display area of the liquid crystal display panel module 400 on a metal plate having a substantially box shape.
For example, it is attached to the resin frame 500 by being locked.

The upper frame 800 also has a function as a shielding material.

[Assembly of the above components] FIG. 6 is a view showing an assembly of the components shown in FIG.
The plan view and the right, left, top and bottom views as viewed from the 0 side show side views as viewed from that direction.

Here, from each of the left and right figures in the figure, the resin frame 5
00 / DC / AC inverter board 40
Are located without protruding from the side surface of the upper frame 800 (in other words, in a state where observation is not possible).

Also, from the left and right figures in the figure, the resin frame 50
0 indicates that the cross section has a U-shape due to the protrusion 500A.

The resin frame 500 having such a shape
As described above, a large opposing force against twisting due to a rotational force in the opposite direction on the diagonal line.

FIG. 7 shows a configuration in which cooling means and a power supply circuit connected to the DC / AC inverter board 40 are mounted on the assembly shown in FIG. It is a perspective view.

In the figure, a shield member 100 is arranged so as to cover the back side of the resin frame 500, and a pair of cooling fans 102A, 1
02B is attached.

Of the pair of cooling fans 102A and 102B, one of the cooling fans 102A is disposed so as to overlap the lower portion of the DC / AC inverter board 40, and the portion of the shield member 100 to which the cooling fan is attached is air. An opening is provided as a distribution channel.

Thus, the air flowing in by the cooling fan 102A cools the lower part of the DC / AC inverter board 40, and the air slightly warmed by the cooling rises. Cooling can be achieved up to.

For this reason, a hole 104 for releasing the air is formed in the upper portion of the shield member 100, so that the air can be sufficiently circulated.

In FIG. 7, the holes 104 are formed in the upper part of the frame so as to be juxtaposed in the x direction. However, it goes without saying that at least both ends of the electrode portion of the cold cathode ray tube 35 may be formed so as to substantially overlap each other, and the diameter of the hole may be increased.

In this case, not only the DC / AC inverter board 40 but also the cold cathode ray tube 35 arranged via the resin frame 500 can be cooled at the same time.

Here, it is known that the cold cathode ray tube 35 is not heated over its entirety, but is particularly heated at the electrode portions at both ends thereof.

For this reason, the one cooling fan 102A
Is disposed so as to overlap with one end of the cold cathode ray tube 35, so that one end of each cold cathode ray tube 35 can be sufficiently cooled.

For this reason, a pair of cooling fans 1
02A and 102B, the other cooling fan 102A
Are arranged so as to overlap with the other end of the cold cathode ray tube 35.

From the above, each cold cathode ray tube 35 is
At each of the two ends (electrode portions), the cooling fans 10A and 102B sufficiently cool the heat so that it does not heat.

This prevents the liquid crystal in the liquid crystal display panel 1 from deteriorating its characteristics due to the heating, and thus has the effect of ensuring long-term quality.

Further, the pair of cooling fans 102A,
Since a relatively large area is formed between the power supply circuits 102B, the space can be effectively used by arranging the power supply circuit 106 connected to the DC / AC inverter board 40.

The shield member 100 is provided to further reinforce the twisting of the assembly shown in FIG.
It is configured to have a side surface 100A bent so as to abut on the side surface of the assembly.

FIG. 8 is a structural view as viewed from the display surface side, and it is clear that the side surface 100A of the shield member 100 is bent so as to abut against the four side surfaces of the assembly.

The shield member 100 has a structure in which the power supply circuit 106 is mounted on the upper surface thereof.
However, the power supply circuit 106 is connected to the shield plate 7 shown in FIG.
It goes without saying that it may be mounted on the second.

In this case, the shield material 100 is formed in such a manner that the corresponding region has a swelling shape,
6 can be shielded, and the propagation of electromagnetic waves to the outside of the liquid crystal display device can be prevented.

In FIGS. 7 and 8, a support is attached below the support, and the liquid crystal display device described in this embodiment can be used as a so-called liquid crystal display monitor.

[Assembly to which the cooling means is attached] FIG.
7 is a diagram showing the configuration shown in FIG. 7 (and FIG. 8), the center of which is a plan view as viewed from the upper frame 800 side, and the left, right, upper and lower views are side views as viewed from that direction.

As is clear from this figure, even when all the components necessary for the liquid crystal display monitor are attached, the thickness can be reduced, and the most important advantage of the liquid crystal display monitor can be maintained. become able to.

[Other Embodiments] In the above-described embodiments, a so-called lateral electric field type liquid crystal display device has been described.

However, it is needless to say that the present invention can be applied to other types of liquid crystal display devices such as a vertical electric field type.

This is because there is only a main difference in the structure of the pixel for controlling the light transmittance of the liquid crystal, and other structures except for the difference are almost the same.

[0127]

As is apparent from the above description,
According to the liquid crystal display device of the present invention, it is possible to suppress the occurrence of color unevenness due to heat.

[Brief description of the drawings]

FIG. 1 is an equivalent circuit diagram showing one embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is an exploded perspective view showing one embodiment of the liquid crystal display device according to the present invention.

FIG. 3 is a plan view showing one embodiment of a configuration of a pixel of the liquid crystal display device according to the present invention.

FIG. 4 is a (back) perspective view showing one embodiment of a resin frame used in the liquid crystal display device according to the present invention.

FIG. 5 shows a DC / DC used in the liquid crystal display device according to the present invention.
FIG. 3 is a plan view showing an example of an arrangement of an AC inverter board.

FIG. 6 is a view showing an assembly of the parts shown in FIG. 2; the center is a plan view as viewed from the observation side;

FIG. 7 is a perspective view showing one embodiment of an arrangement of a cooling fan used in the liquid crystal display device according to the present invention.

FIG. 8 is a perspective view showing a configuration when the configuration shown in FIG. 7 is viewed from the opposite side.

FIG. 9 is a diagram showing the configuration shown in FIG. 7 (and FIG. 8);
The center is a plan view as viewed from the observation side, and the left, right, upper and lower views are side views as viewed from that direction.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display panel, 10 ... Control board, 40 ...
DC / AC inverter board, 71 transformer, 72 shield plate, 300 backlight unit, 500 resin frame, 500A projecting portion, 500B side surface portion, 102
A, 102B: cooling fan, 106: power supply circuit. 400
... Liquid crystal display panel module, 700 ... Medium frame, 8
00 ... upper frame.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yoshinori Tanaka 3300 Hayano, Mobara-shi, Chiba F-term in the Electronic Devices Division, Hitachi, Ltd. (Reference) 2H091 FA14Z FA42Z GA13 LA04 LA18 2H092 JA24 NA25 PA13 2H093 NA16 NC80 ND09 NE10

Claims (6)

[Claims] 1. A liquid crystal display monitor comprising a support base and a liquid crystal display monitor supported by the support base, wherein the liquid crystal display monitor has a liquid crystal display panel,
A backlight unit disposed on the back side of the liquid crystal display panel, the backlight unit comprising a plurality of cathode ray tubes arranged in parallel to face the liquid crystal display panel; A liquid crystal display device comprising: a reflection plate for guiding the light source to a side; and a cooling fan provided on the outer frame, wherein the cooling fan is arranged at a position overlapping with an electrode of the cathode ray tube. 2. The liquid crystal display device according to claim 1, wherein the cooling fan is arranged at a position overlapping with an electrode of the cathode ray tube arranged close to the support table. 3. A cooling fan comprising two cooling fans, one of which is superimposed on one of the electrodes at both ends of the cathode ray tube, and the other is superposed on the other electrode. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is arranged. 4. The two cooling fans are arranged close to the support base, one of the cooling fans is arranged so as to overlap one electrode of the cathode ray tube, and the other cooling fan is arranged on the other side of the cathode ray tube. The liquid crystal display device according to claim 3, wherein the liquid crystal display device is arranged so as to overlap with the electrodes. 5. A liquid crystal display monitor includes, in its outer frame, a liquid crystal display panel, a backlight unit disposed on the back of the liquid crystal display panel, and a shield plate disposed on the entire rear surface of the backlight unit. 2. The liquid crystal display device according to claim 1, wherein a ventilation hole is formed in the shield plate. 6. The liquid crystal display device according to claim 5, wherein the ventilation holes are formed at positions overlapping the electrodes of the cathode ray tube.