JPH09307257A - Image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leaking of an unusual sound caused by the plasma discharge of a PDP at low voltage to the outside of a housing, to suppress temperature rise by cooling the PDP, and to exhibit full performance. SOLUTION: A housing 1 is formed in required film thickness of synthetic resin, etc., the front of the housing 1 is formed by double reinforced glass 2, a void 3 is provided, and the dew concentration generated by the cooling of the housing is prevented. Ventilating space is provided on the front side of the PDP 4, refrigeration cycle cooling unit 6 is provided behind a circuit board, and a ventilating fan 7 is provided on the lower part. The cooling unit is connected to a heat dissipating unit 8 by two refrigerant pipes 11 and 12, the heated refrigerant is compressed by a compressor 9, heat is radiated by a heat radiator 10, and cooled refrigerant is sent to the cooler by a refrigerant pipe 12. The air cooled by the cooling unit is circulated in the housing by an air blasting fan as shown by the arrows, and the PDP and the circuit board are cooled. A temperature sensor 13 is provided in the housing, and the refrigerant cycle and the air blasting fan are operated when air is in the temperature higher than required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device using a plasma display panel (PDP), which is provided with a cooling device to cool the inside of a housing to suppress deterioration of PDP performance and improve brightness and contrast. Regarding what you do.

[0002]

2. Description of the Related Art Since a PDP has a smaller depth than a cathode ray tube having the same screen size, the depth of the housing can be greatly reduced by mounting a circuit board on which a driving circuit and the like are mounted on the back surface of the PDP. However, the PDP generates heat by plasma discharge, and the temperature of the PDP itself rises due to this heat, and at the same time, the circuit board is warmed. The PDP has a problem that the luminous efficiency of the phosphor is lowered due to the temperature rise, the luminance is lowered, and the luminance is further lowered if the lighting time is limited to suppress the temperature rise. Further, the temperature rise of the circuit board causes the driving circuit to have a problem. Since the reliability of the parts deteriorates, there is a problem that parts having a sufficient temperature rating must be used.

Therefore, in the image display device using the PDP, the heat radiation of the PDP is emphasized. For example, as shown in FIG. 2, the axial fan 21 is provided behind the circuit board 5 on the back surface of the PDP 4.
Etc. are provided, and the outside air is sucked in from the bottom of the housing 22 or the like, and the PDP 4
And between the circuit board 5 and the back of the circuit board 5, and the air is discharged to the outside of the housing from the ventilation holes 23 on the back surface of the housing.
Also, the circuit board 5 is cooled. Note that P
An optical filter is provided on the front surface of DP4 to prevent reflection of external light.
Since 24 is provided, it is effective to dissipate the optical filter 24 by using a material with good heat conduction, but it is necessary to prevent it from feeling hot when touched by human hands. For some reason, the optical filter 24 is currently made of a plastic material having poor heat conduction, and the heat dissipation effect of the optical filter 24 cannot be expected.

The PDP 4 encloses xenon gas or the like in a space hermetically sealed by two glass substrates, excites molecules such as xenon gas by the discharge between the electrodes to generate ultraviolet rays, and the inside is coated with the ultraviolet rays. The fluorescent substance is excited to emit light in the visible light region. Due to this discharge (plasma discharge), the volume of xenon gas or the like expands, the glass substrate vibrates, and abnormal noise is generated. The air pressure in the sealed space between the glass substrates is about several tens of atmospheres, and in the lowlands, the two glass substrates are pressed by the atmospheric pressure, so that the vibration is suppressed and the abnormal noise is a level that is not so noticeable. But PDP
When the air pressure is low, for example, when operating in an airplane in flight or at high altitude, the glass substrate is apt to vibrate because the pressing force from outside the glass substrate is relatively reduced, and the level of abnormal noise is reduced. Get higher

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a closed casing for the image display device to reduce the leakage level of abnormal noise, and to provide a cooler and a blower fan for the refrigeration cycle in the casing. Provided, the radiator of the refrigeration cycle is arranged outside the housing, and the air cooled by the cooler is circulated in the housing by the blower fan to cool the PDP and to maximize the performance of the PDP. is there.

[0006]

In order to solve the above-mentioned problems, the present invention provides a PDP, a refrigerating cycle cooler composed of a cooler and a radiator, and a blower fan in a sealed housing. And a radiator of the refrigeration cycle is provided outside the housing, and the PDP is cooled by the cool air from the cooler.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a video display device according to the present invention,
The housing is made of a synthetic resin material with heat insulation to form a closed structure,
A PDP, a cooler, and a blower fan are arranged inside, and a radiator that constitutes a refrigeration cycle with this cooler is arranged outside the housing. The cooler is arranged on the back side of the PDP to cool the blower fan. Placed below the container, the part of the front of the housing facing the image display surface of the PDP has a double structure of tempered glass, and a ventilation space is provided between the front part of the housing including the glass part and the PDP to rotate the blower fan. The air cooled by the cooler is blown toward the lower end of the ventilation space so that the air passing through the ventilation space forms a circulation path from the upper end of the ventilation space toward the cooler, and the temperature sensor is provided in the housing. When the temperature inside the housing rises above the required temperature, the refrigeration cycle and the blower fan are operated to lower the temperature of the PDP so that the PDP operates in the best condition.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a video display apparatus according to the present invention. FIG. 1 is a side sectional view of an essential part of an embodiment of an image display device according to the present invention. In the figure, reference numeral 1 denotes a housing, which is made of a synthetic resin material or the like. Reference numeral 2 is a tempered glass, which has a double structure and a void 3 is provided in the middle. 4 is PD
P and 5 are circuit boards on which a driving circuit of the PDP 4 and the like are arranged,
It is attached to the back of PDP4. 6 is a cooler, 7 is a blower fan, 8 is a heat exhaust unit, 9 is a compressor in the heat exhaust unit 8, 10 is a radiator, 11 and 12 are refrigerant pipes, and these cooler 6, compressor 9, radiator 10 , Refrigerant pipe 11
And 12 constitute a refrigeration cycle. A temperature sensor 13 detects the temperature inside the housing 1.

Next, the operation of the image display device according to the present invention will be described. The PDP 4 is driven by a signal from the circuit board 5 based on the video signal, and excites molecules such as xenon gas enclosed in the glass substrate by plasma discharge to generate ultraviolet rays and excite the fluorescent substance coated inside. Then, light in the visible light region is emitted to display an image. The housing 1 is made of a synthetic resin material to a required thickness, and a tempered glass 2 is formed on the front surface.
(Double structure) is used to form a closed structure, and the strength necessary for holding the PDP 4 and the like is obtained and at the same time, the heat insulating property is provided. The reason why the tempered glass 2 is used is to prevent the glass from being broken and the fragments not to be scattered when a strong impact is applied from the outside. This is to prevent deformation (expansion) due to the difference between the external pressure and the atmospheric pressure inside the housing when installed inside the aircraft or in a place with high altitude. In addition, the reason why the void 3 is formed by using the two tempered glasses 2 is to prevent dew condensation on the glass due to the temperature difference from the outside air due to the cooling inside the housing 1.

The PDP 4 is attached by providing a ventilation space having an appropriate width between the housing 1 and the tempered glass 2. Cooler 6
Is disposed behind the circuit board 5 and is connected to the heat exhausting unit 8 through the refrigerant pipes 11 and 12. Then, the compressor 9 in the exhaust heat unit 8 compresses the refrigerant into high temperature and high pressure, sends it to the radiator 10, condenses and liquefies it by heat exchange with the outside air (exhaust heat), and sends it into the housing 1 through the refrigerant pipe 12, After decompressing with a capillary tube or the like, the cooler 6 exchanges heat (absorbs heat) with the air inside the housing 1 to cool the air inside the housing 1. The refrigerant that has become low-pressure gas due to heat exchange returns to the compressor 9 through the refrigerant pipe 11. The air cooled by the cooler 6 is blown by the blower fan 7 in the direction of the arrow, passes through the ventilation space in front of the PDP 4, and is heated by the heat generated by the PDP 4 (PDP).
4) and then enters the cooler 6 through the upper end of the PDP 4. Then, a circulation path is formed in which the air is cooled by the cooler 6 again and is blown by the blower fan 7. For the blower fan 7, for example, a cross flow fan is used, and P
Make sure to send cold air evenly over the entire width of DP4.

A temperature sensor 13 is attached to a ceiling portion or the like inside the housing 1 to detect the temperature inside the housing 1, and when the temperature exceeds a required temperature, the refrigeration cycle and the blower fan 7 are operated. In the above description, the refrigeration cycle is described as an example of a refrigerant compression type that is configured by the cooler 6, the compressor 9, the radiator 10, etc., but liquid ammonia or the like is heated under high pressure and sent to the cooler to evaporate. An absorption type refrigeration cycle in which the air inside the housing 1 is cooled by the heat of evaporation may be used.
Since this method does not use the compressor 9, there is an advantage that no noise countermeasure is required due to the operation of the compressor.

In the above description, an example in which the cooler of the refrigeration cycle is arranged inside the housing has been described. However, the cooler is installed outside the housing together with the compressor and the radiator, and two cooling devices are provided between the housing and the housing. Connect with a ventilation pipe, send cool air from the cooling device into the housing with one ventilation pipe, circulate this cold air inside the housing with a blower fan, and return warmed air to the cooling device with the other ventilation pipe Good.

As described above, by providing the refrigeration cycle to cool the inside of the housing, the temperature rise of the PDP 4 is suppressed and the luminous efficiency of the phosphor is not lowered, so that a high-luminance image can be displayed and the circuit board Since the temperature rise is suppressed, the reliability of components such as the drive circuit is improved. Further, by making the casing 1 have a closed structure, the level of leakage of abnormal noise generated by plasma discharge of the PDP 4 to the outside of the casing is reduced,
Even when the atmospheric pressure is lower than that on a flat ground, for example, when installed in an airplane in flight or at a high altitude, the abnormal noise of the PDP is hardly noticeable.

[0014]

As described above, according to the image display device of the present invention, the refrigeration cycle is provided to cool the inside of the housing, so that the temperature rise of the PDP is suppressed and the luminous efficiency of the phosphor is not lowered. Therefore, a high-luminance image can be displayed, and the temperature rise of the circuit board is suppressed, so that the reliability of components such as the drive circuit is improved. In addition, since the housing has a closed structure, PD
The leakage level of abnormal noise due to the plasma discharge of P to the outside of the housing is reduced, and the atmospheric pressure is lower than that on a flat ground, for example,
P even when installed in a flying aircraft or at high altitude
The abnormal noise of DP is almost unnoticeable.

[Brief description of drawings]

FIG. 1 is a side sectional view of an essential part of an embodiment of an image display device according to the present invention.

FIG. 2 is a side sectional view of an essential part of an example of a conventional image display device.

[Explanation of symbols]

 1 Housing 2 Reinforced Double-Glass 4 Plasma Display Panel (PDP) 5 Circuit Board 6 Cooler 7 Blower Fan (Cross Flow Fan) 9 Compressor 10 Radiator

Claims (5)

[Claims] 1. A plasma display panel, a cooler of a refrigeration cycle including a cooler and a radiator, and a blower fan are arranged in a closed housing, and the radiator of the refrigeration cycle is housed in the enclosure. An image display device arranged outside to cool a plasma display panel by cooling air from the cooler. 2. The cooler is arranged on the back side of the plasma display panel, the blower fan is arranged below the cooler, and a ventilation space is provided between the housing and the front surface of the plasma display panel. By the rotation of the blower fan, the air cooled by the cooler is blown toward the lower end of the ventilation space, and the air passing through the ventilation space forms a circulation path from the upper end of the ventilation space toward the cooler. The image display device according to item 1. 3. The housing is formed of a synthetic resin material having a heat insulating property, and a portion facing the image display surface of the plasma display panel has a double structure of tempered glass, and a void is provided between the tempered glass. Claim 1 or Claim 2 which is configured to prevent dew condensation on the glass surface due to cooling of the inside.
The image display device according to the above. 4. The refrigeration cycle and the blower fan are operated when a temperature sensor is provided in the housing and the temperature in the housing is equal to or higher than a required temperature. 3. The image display device according to item 3. 5. A plasma display panel and a blower fan are arranged in a closed casing, a refrigerating device is attached outside the casing, and the casing and the refrigerating device are connected by two ventilation pipes. The air cooled by the ventilation device is sent to the inside of the housing by the ventilation pipe, the air is circulated in the housing by the air blowing fan, and the air warmed inside the housing is returned to the cooling device by the other ventilation pipe, and the plasma display panel A video display device designed to cool down.