JP2004072386A - Video display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video display device capable of efficiently suppressing temperature elevation inside a case body no matter which one of a normal installation state and a vertically inverted installation state it is used in. <P>SOLUTION: The video display device suppresses the temperature elevation inside the case body by ventilating the inside of the case body by using cooling fans 20, 30a and 30b. An up/down detection sensor 17 for detecting that the device is vertically inverted and installed is provided, and on the basis of the detection output of the up/down detection sensor 17, the drive of the cooling fans 20, 30a and 30b is controlled and a ventilating direction is varied. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a video display device such as a television receiver, and more particularly to a video display device capable of suppressing a rise in the temperature inside a housing when the housing is turned upside down.
[0002]
[Prior art]
A conventional video display device of this type will be described with reference to FIGS. 7 and 8 for a liquid crystal display device using, for example, a liquid crystal panel as a display device. Here, FIG. 7 shows a schematic configuration of a conventional image display device, (a) a side sectional view, (b) a rear view, and FIG. 8 (a) a state in which the image display device is normally installed, and (b) a vertically inverted installation. It is explanatory drawing which shows the external appearance of the state which carried out.
[0003]
As shown in FIG. 7, a conventional liquid crystal display device includes a liquid crystal panel 1 for displaying an image, a fluorescent lamp 2 for irradiating a backlight from the back of the liquid crystal panel 1, and a light for irradiating from the fluorescent lamp 2. The liquid crystal panel 1 includes a reflector (panel shield) 3 for reflecting light toward the liquid crystal panel 1 and an optical sheet 4 for uniformly diffusing irradiation light from the fluorescent lamp 2 and entering the liquid crystal panel 1.
[0004]
On the back side of the reflection plate (panel shield) 3 (on the opposite side of the liquid crystal panel 1), various circuit boards 5 including a liquid crystal panel 1, a driving circuit of the fluorescent lamp 2, and the like are arranged. The members 1 to 5 are housed in a housing including a front cabinet 6 and a back cabinet 7.
[0005]
An intake hole 8 is provided in a lower portion (lower end surface in the normal installation state) of the back cabinet 7, and an exhaust hole 9 is provided in an upper portion (upper end surface in the normal installation state). In the vicinity, a cooling fan (exhaust fan) 10 that exhausts the air inside the housing to suppress a rise in the temperature inside the housing is provided.
[0006]
That is, when the cooling fan 10 is rotationally driven, a ventilation passage is formed to pass from the intake hole 8 on the lower end surface to the exhaust hole 9 on the upper end surface, and is generated from the fluorescent lamp 2 and the power supply circuit unit on the circuit board 5. It is possible to release heat outside the housing. As described above, in the conventional video display device, the cooling fan 10 is used to ventilate the inside of the housing from bottom to top, thereby suppressing the temperature rise inside the housing.
[0007]
[Problems to be solved by the invention]
By the way, in this type of image display device, in addition to a normal installation state where the image display device is mounted on a support stand (stand) 11 as shown in FIG. 8A, for example, as shown in FIG. There is a demand for viewing a display image even in a vertically inverted installation state where the display image is suspended from the ceiling via the arm 12.
[0008]
In this case, since the common mounting portion 13 of the support base 11 and the mounting arm 12 is provided below the back cabinet 7, furthermore, in order to maintain the viewing angle characteristics of the liquid crystal panel 1 in any installation state. The mounting is performed such that the upper part in the normal installation state is the lower part in the upside-down installation state.
[0009]
Therefore, in the upside-down installation state, the intake hole 8 is located above and the exhaust hole 9 is located below, and the direction of air flow in the housing by the cooling fan 10 is reversed. That is, contrary to the action of the hot air flow, the air in the housing is forcibly sent from the top to the bottom, and the effect of releasing heat to the outside of the housing is reduced, and the inside of the housing cannot be cooled efficiently. .
[0010]
The present invention has been made in view of the above-described problems, and it is possible to efficiently suppress a temperature rise inside a housing even when used in any of a normal installation state and an upside-down installation state. An image display device is provided.
[0011]
[Means for Solving the Problems]
A first invention of the present application is a video display device that suppresses a rise in temperature inside a housing by ventilating the inside of the housing using a cooling fan, and detects that the device is installed upside down. And a control means for controlling the driving of the cooling fan based on the detection output of the detection means and changing the direction of the ventilation.
[0012]
The second invention of the present application is characterized in that the control means variably controls the rotation direction of the cooling fan.
[0013]
The third invention of the present application is characterized in that a plurality of the cooling fans are provided, and the control means variably controls the rotation direction of each of the plurality of cooling fans.
[0014]
A fourth invention of the present application is characterized in that a plurality of the cooling fans are provided, and the control means variably controls the drive / stop of each of the plurality of cooling fans.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of a video display device of the present invention will be described in detail with reference to FIGS. 1 to 3 for a television receiver using, for example, a liquid crystal display panel. The reference numerals are used, and the description is omitted.
[0016]
Here, FIG. 1 is a side sectional view showing a normal installation state in the television receiver of the present embodiment, (b) a rear view, and FIG. 2 is a vertically inverted installation state of the television receiver of the embodiment. FIG. 3A is a side sectional view, FIG. 3B is a rear view, and FIG. 3 is a block diagram illustrating a schematic configuration of a main part of the television receiver of the present embodiment.
[0017]
As shown in FIGS. 1 and 2, the television receiver of the present embodiment is provided with an up / down detection sensor 17, which can determine whether the device is in a normal installation state or in a vertically inverted installation state. It is possible. In addition, as the vertical sensor 17, various sensors such as a gravitational switch that outputs a detection signal when the device is placed upside down and a gyro sensor can be used.
[0018]
Further, ventilation holes 18 and 19 are provided above (upper end surface) and below (lower end surface) the back cabinet 7, and a reversible fan 20 is provided near one of the ventilation holes 19. The reversible fan 20 can be driven to rotate in the normal direction or the reverse direction depending on the polarity of the applied voltage, and can reverse the air blowing direction based on the detection result of the vertical sensor 17.
[0019]
That is, when the reversible fan 20 is determined to be in the normal installation state by the detection result of the vertical detection sensor 17, it functions as an exhaust fan (FIG. 1) and is determined to be in the upside down installation state. In this case, it works with the intake fan (FIG. 2). This allows the reversible fan 20 to constantly ventilate the inside of the housing from bottom to top, regardless of whether the device is used in the normal installation state or in the upside-down state, and thus the inside of the housing can be efficiently used. Temperature rise can be suppressed.
[0020]
In FIG. 3 showing the television receiver of the present embodiment, reference numeral 31 denotes a tuner for outputting a video signal of a specified channel from a television broadcast wave received from an antenna (not shown), and 32 denotes a tuner selected by the tuner 31. An image processing unit 33 for performing various image processing on the video signal is a panel driving unit that drives a voltage application electrode of the liquid crystal panel 1 based on an output signal of the image processing unit 32.
[0021]
35 controls the panel drive unit 33 so that the image displayed on the liquid crystal panel 1 is inverted up and down and left and right based on the detection result of the up and down detection sensor 17, and reverses the rotation direction of the reversible fan 20. And a microcomputer that controls the fan power supply unit 36. The fan power supply unit 36 switches the polarity of the power supply voltage supplied to the reversible fan 20 in response to an instruction from the microcomputer 35. The rotation direction of the reversible fan 20 is reversed by the polarity switching of the supply power supply voltage.
[0022]
As described above, the television receiver of the present embodiment always changes the direction of air flow inside the housing from bottom to top by changing the rotation direction of the reversible fan 20 between the normal installation state and the upside-down installation state. It is possible to efficiently suppress the temperature rise inside the housing.
[0023]
Next, a video display apparatus according to a second embodiment of the present invention will be described with reference to FIGS. 4 to 6 for a television receiver using a liquid crystal panel, for example. And a description thereof will be omitted.
[0024]
Here, FIG. 4A is a side sectional view showing a normal installation state in the television receiver of the present embodiment, FIG. 4B is a rear view, and FIG. 5 is a vertically inverted installation state of the television receiver of the embodiment. FIG. 6A is a side sectional view, FIG. 6B is a rear view, and FIG. 6 is a block diagram illustrating a schematic configuration of a main part of the television receiver of the present embodiment.
[0025]
As shown in FIGS. 4 and 5, the television receiver of the present embodiment is provided with reversible fans 30a and 30b in each of the ventilation holes 18 and 19, and uses two reversible fans 30a and 30b to form a housing. This is to form the internal ventilation direction. Here, each of the reversible fans 30a and 30b is set so that the power supply polarity is opposite to each other, and further, each of the reversible fans 30a and 30b reverses the blowing direction based on the detection result of the up-down detection sensor 17. be able to.
[0026]
That is, when the apparatus is determined to be in the normal installation state based on the detection result of the up-down detection sensor 17, the reversible fan 30a acts as an exhaust fan and the reversible fan 30b acts as an intake fan (FIG. 4). When it is determined that the state is the state, the reversible fan 30a acts as an intake fan and the reversible fan 30b acts as an exhaust fan (FIG. 5).
[0027]
Thus, even when the device is used in either the normal installation state or the upside-down state, the inside of the housing can always be ventilated from the bottom to the top by the reversible fans 30a and 30b, and the housing can be efficiently used. The temperature rise inside the body can be suppressed. Further, since the two reversible fans 30a and 30b are used, not only can the cooling effect be further enhanced, but also the reversible fans 30a and 30b with less noise can be employed.
[0028]
In FIG. 6 showing the television receiver of the present embodiment, reference numeral 46 denotes a fan power supply that switches the polarity of the power supply voltage supplied to the reversible fans 30a and 30b in response to an instruction from the microcomputer 35. The rotation direction of the reversible fans 30a and 30b is reversed by the polarity switching of the supply power supply voltage.
[0029]
As described above, the television receiver of the present embodiment always changes the direction of air flow inside the housing by changing the rotation direction of the two reversible fans 30a and 30b between the normal installation state and the upside-down installation state. The temperature can be increased from the bottom to the top, so that the temperature inside the housing can be efficiently prevented from rising.
[0030]
In the above-described second embodiment, a description has been given of a case where two reversible fans are provided, each of which is set to rotate in the reverse direction. However, three or more reversible fans are provided at appropriate locations in the device housing. Needless to say, the cooling efficiency may be further increased.
[0031]
Also, in the above-described embodiment of the present invention, the case where the ventilation direction inside the housing is variably formed using the reversible fan has been described. However, a unidirectional irreversible fan is provided at a plurality of appropriate locations inside the device housing. Alternatively, the rotation driving / stopping may be variably controlled according to the installation state.
[0032]
That is, by detecting whether the device is in the normal installation state or the upside-down installation state and controlling the rotation / stop of the plurality of cooling fans, the ventilation direction inside the housing is always changed from bottom to top. It is possible to efficiently suppress the temperature rise inside the housing.
[0033]
Furthermore, in the above-described embodiment of the present invention, a television receiver using a liquid crystal panel as a display device has been described. However, the present invention is not limited to this, and it is possible to view an installation state upside down. It is obvious that the present invention may be applied to all video equipment that requires cooling inside the device housing.
[0034]
【The invention's effect】
Since the liquid crystal display device of the present invention is configured as described above, it is possible to always obtain an efficient cooling effect by changing the ventilation direction inside the housing according to the installation state.
[Brief description of the drawings]
FIG. 1A is a side sectional view showing a normal installation state of a video display device according to a first embodiment of the present invention, and FIG.
FIGS. 2A and 2B are a side sectional view and a rear view, respectively, showing a vertically inverted installation state of the liquid crystal display device according to the first embodiment of the present invention.
FIG. 3 is a block diagram illustrating a schematic configuration of a main part of the liquid crystal display device according to the first embodiment of the present invention.
4A is a side sectional view and FIG. 4B is a rear view showing a normal installation state of a video display device according to a second embodiment of the present invention.
FIGS. 5A and 5B are a side sectional view and a rear view, respectively, showing a vertically inverted installation state of a liquid crystal display device according to a second embodiment of the present invention.
FIG. 6 is a block diagram illustrating a schematic configuration of a main part of a liquid crystal display device according to a second embodiment of the present invention.
7A is a side sectional view showing a schematic configuration of a conventional video display device, and FIG.
FIGS. 8A and 8B are explanatory views showing appearances of the image display device in a state where it is normally installed, and FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2 Fluorescent lamp 3 Reflector 4 Optical sheet 5 Circuit board 6 Front cabinet 7 Back cabinet 17 Vertical detection sensor 18, 19 Vent hole 20 Reversible fan 30a, 30b Reversible fan 31 Tuner 32 Video processing unit 33 Panel driving unit 35 Microcomputer 36 Fan power supply unit 46 Fan power supply unit

Claims (4)

A video display device that suppresses a temperature rise inside the housing by ventilating the inside of the housing using a cooling fan,
Detecting means for detecting that the device is installed upside down,
A video display device comprising: a control unit that controls driving of the cooling fan based on a detection output of the detection unit and changes the ventilation direction. The video display device according to claim 1,
The image display device, wherein the control means variably controls a rotation direction of the cooling fan. The video display device according to claim 2,
A plurality of cooling fans,
The image display device, wherein the control means variably controls the rotation direction of each of the plurality of cooling fans. The video display device according to claim 1,
A plurality of cooling fans,
The image display device, wherein the control means variably controls the drive / stop of each of the plurality of cooling fans.

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