JP2009288687A - Image projection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable sufficient cooling of another cooling object part without increasing the rotation speed of a fan when using air used in cooling of a cooling object part in cooling of the other cooling object part. <P>SOLUTION: An image projection apparatus includes a first cooling object part 17, a second cooling object part 9, and a cooling structure for supplying air cooling the first cooling object part to the second cooling object part with the fan 12 to cool the second cooling object part. The cooling structure includes a heat absorption part 16A formed of a metal and for absorbing heat from the air supplied to the second cooling object part with the fan and a heat radiation part 16B formed of the metal and thermally connected to the heat absorption part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image projection apparatus such as a projector, and more particularly to a cooling structure in an image projection apparatus.

  In projectors, high brightness and low noise are important, and from the viewpoint of recycling and ecology, disassembly is easy and low power consumption is also desired.

In order to realize low noise and low power consumption, there is a method of reducing the number of fans for cooling a cooling target part such as a heat generating part inside the projector. Patent Document 1 discloses a configuration in which two cooling target parts are cooled by one fan. Specifically, a cooling fan is disposed between the color separation / synthesis system and the light source unit, and air that has cooled the color separation / synthesis system is sent to the light source unit to be used for cooling the light source unit.
JP 2004-61569 A

  However, the temperature of the air used for cooling one of the two objects to be cooled has risen to some extent, and in order to sufficiently cool the other object to be cooled by this air, it is necessary to increase the air volume. For this reason, even if the number of fans is reduced, the number of rotations of the fan must be increased, and as a result, it is difficult to realize low noise and low power consumption.

  In the present invention, when the air used for cooling the cooling target part is also used for cooling the other cooling target part, sufficient cooling of the other cooling target part can be performed without increasing the number of rotations of the fan. A possible image projection apparatus is provided.

  An image projection apparatus according to one aspect of the present invention sends a first cooling target part, a second cooling target part, and air that has cooled the first cooling target part to the second cooling target part by a fan, And a cooling structure for cooling the second cooling target portion. The cooling structure includes a heat absorbing portion that is formed of metal and absorbs heat from the air sent to the second cooling target portion by the fan, and a heat radiating portion that is thermally connected to the heat absorbing portion. Features.

  According to the present invention, the heat absorption part can absorb the heat from the air whose temperature has increased by cooling the first cooling target part, and can reduce the temperature of the air. Moreover, the heat absorbing action at the heat absorbing portion can be maintained by the heat radiation at the heat radiating portion. Therefore, it is possible to sufficiently cool the first and second cooling target parts without increasing the number of rotations of the fan, and it is possible to realize low noise and low power consumption of the image projection apparatus.

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

  FIG. 1 shows the appearance of a projector (image projection apparatus) that is an embodiment of the present invention.

  In FIG. 1, 1 is an upper casing (exterior member) of the projector, and 2 is a lower casing (exterior member). Reference numeral 3 denotes a side plate (exterior member) in which an opening for discharging heat generated in the housings 1 and 2 together with air (cooling air) is formed.

  Although not shown, the side plate opposite to the side plate 3 is provided with an opening for taking in outside air and an interface connector section for inputting and outputting video signals.

  Reference numeral 4 denotes a projection lens unit for enlarging and projecting light from an image display element (not shown) such as a liquid crystal panel onto a projection surface such as a screen.

  FIG. 2 shows the internal structure of the projector. Most of the components inside the projector are held by the lower housing 2.

  5 is an optical box containing a color separation / synthesis optical system for color-separating illumination light from a light source lamp (not shown) and guiding it to a plurality of image display elements and synthesizing image lights modulated by the plurality of image display elements. It is. The color separation / synthesis optical system includes various optical elements such as a dichroic mirror, a polarizing beam splitter, a polarizing plate, and a phase plate. The plurality of image display elements are housed in the optical box 5 together with the color separation / synthesis optical system.

  The portion indicated by reference numeral 6 in the optical box 5 converts the illumination light (diverging light) from the light source lamp into a parallel light beam, aligns the polarization direction of the illumination light, or converts the illumination light into a plurality of light beams. An illumination optical system having a function of superimposing on the image forming element after being disassembled is accommodated.

  Reference numeral 7 denotes a lamp box containing a light source lamp. Reference numeral 8 denotes a lamp exhaust fan for discharging the air that has cooled the light source lamp to the outside of the casings 1 and 2.

  Reference numeral 9 denotes a power supply board unit, in which a power supply board for supplying power to each part other than the lamp in the projector and a ballast power supply board for supplying power to the lamp are accommodated.

  Reference numeral 10 denotes a power supply exhaust fan for mainly discharging the air that has cooled the power supply board unit 9 to the outside of the casings 1 and 2.

  A signal board unit 11 performs various processes and controls for driving the image display element based on the video signal input from the outside through the interface connector unit described above.

  Reference numeral 12 denotes a panel cooling fan for cooling components constituting an optical system such as an image display element housed in the optical box 5.

  A lamp duct 13 guides cooling air into the lamp box 7 in order to control the lamp temperature.

  Reference numeral 14 denotes a lamp cooling fan for sending wind (air) to the lamp duct 13. An exhaust box plate 15 closes the upper surface of the exhaust box that guides the air that has cooled the lamp to the lamp exhaust fan 8.

  FIG. 3 shows a state in which some of the components shown in FIG. 2 are removed. In FIG. 3, components on the lower housing 2 are shown in a different direction from that in FIG. 2.

  Reference numeral 16 denotes a ground connection sheet metal for connecting the power supply board unit 9 and the signal board unit 11 to the ground. The ground connection sheet metal 16 is disposed along the inner surface (bottom surface) of the lower housing 2 and also functions as an electromagnetic shield member that shields electromagnetic waves generated from the power supply board unit 9 and the signal board unit 11. 9B is the aforementioned ballast substrate, and 9D is the aforementioned power supply substrate.

  Reference numeral 17 denotes a panel prism unit (first cooling target portion or first heat generating portion) in which the above-described color separation / synthesis optical system and image display element are unitized. The panel prism unit (particularly, the image display element) 17 is cooled by generating air flow in the optical box 5 by sucking air with the panel cooling fan 12. The air sucked by the panel cooling fan 12 is outside air taken in from the outside air inlet 2A formed on the upstream side of the panel prism unit 17 in the lower housing 2, so that the panel prism unit 17 is efficiently cooled. Can do.

  On the other hand, the air discharged from the panel cooling fan 12 is used for cooling the power supply board unit (second cooling target part or second heat generating part) 9 including the ballast board 9B and the power supply board 9D. In other words, this embodiment has a cooling structure in which the panel cooling fan 12 is disposed between the panel prism unit 17 and the power supply board unit 9. The cooling structure sends the air that has cooled the panel prism unit 17 to the power supply board unit 9 by the panel cooling fan 12 to cool the power supply board unit 9.

  However, the air discharged from the panel cooling fan 12 is air used for cooling the panel prism unit 17. For this reason, immediately after being discharged from the panel cooling fan 12, the temperature of the air is higher than the temperature of the outside air.

  If the air discharged from the panel cooling fan 12 is used for cooling the power supply board unit 9 while the temperature is high, the cooling efficiency of the power supply board unit 9 is lowered.

  Therefore, in this embodiment, a part of the duct 20 that guides the air discharged from the panel cooling fan 12 to the power supply board unit 9 from the panel cooling fan 12 is constituted by a heat absorbing portion 16A formed of metal (sheet metal). is doing. As shown in FIG. 4, the heat absorbing portion 16 </ b> A is formed by processing a part of the ground connection sheet metal 16. That is, the heat absorbing portion 16 </ b> A is manufactured as a member integrated with the ground connection sheet metal 16.

  As the air discharged from the panel cooling fan 12 and guided to the power supply board unit 9 through the duct 20 flows while contacting the heat absorbing portion 16A, the heat absorbing portion 16A absorbs heat from the air. As a result, the temperature of the air is lower than the temperature immediately after being discharged from the panel cooling fan 12, and air having a relatively low temperature is supplied to the power supply board unit 9. Thereby, the power supply board unit 9 can be efficiently cooled.

  The heat absorbing portion 16A is thermally connected to a portion 16B of the ground connection sheet metal 16 other than the heat absorbing portion 16A. Since the ground connection sheet metal 16 is made of metal, it has higher thermal conductivity than the resin. Moreover, it has a larger area than the heat absorbing portion 16A. Accordingly, the portion 16B functions as a heat radiating portion that dissipates (that is, radiates) heat absorbed by the heat absorbing portion 16A.

  Since there is a heat radiating part 16B thermally connected to the heat absorbing part 16A, the heat absorbed by the heat absorbing part 16A is efficiently dissipated, and the temperature of the heat absorbing part 16A itself that absorbs heat from the air from the panel cooling fan 12 Suppresses the rise. For this reason, even if the projector is used for a long time, the endothermic action by the endothermic portion 16A can be maintained, and the decrease in the cooling efficiency of the power supply board unit 9 can be suppressed.

  According to the inventor's experiment, when a part of the duct 20 is made of a metal heat-absorbing part 16A as in the present embodiment, the FET mounted on the ballast substrate is compared with the case where the duct 20 is formed of only resin. The effect which reduces the temperature of components, such as 3-4 degreeC, has been confirmed. Since the power supply board and the ballast board are equipped with many elements that become high in temperature, the cooling efficiency of the present embodiment can be greatly improved by adopting the cooling structure of this embodiment.

  By reducing the temperature of the air sent from the panel cooling fan 12 to the power supply board unit 9 by providing the heat absorbing portion 16A, the number of rotations of the panel cooling fan 12 is reduced as compared with the case where the duct 20 is formed of only resin. be able to. Therefore, it is possible to realize low noise and low power consumption of the projector.

  Further, as described above, since the ground connection sheet metal 16 also has an electromagnetic shielding effect, it is not necessary to give the casing an electromagnetic shielding effect by applying a conductive coating to the inner surface of the casing. For this reason, the disassembling process of the projector is facilitated, and the recyclability is improved.

  The embodiments described above are merely representative examples, and various modifications and changes can be made to the embodiments when the present invention is implemented.

  For example, in the above embodiment, the case where the heat absorbing portion 16A is integrally formed with the ground connection sheet metal 16 has been described. However, a member corresponding to the heat absorption portion 16A is manufactured as a separate member from the ground connection sheet metal 16, and both are heated. May be connected to each other. The thermal connection may be a direct connection between the two or a connection in which a member having high thermal conductivity is interposed between the two.

  Moreover, although the said Example demonstrated the case where a part of duct 20 was comprised by 16 A of heat absorption parts, you may comprise the whole duct as a metal heat absorption part.

  Furthermore, in the above-described embodiment, the case where the first cooling target portion is the panel prism unit 17 and the second cooling target portion is the power supply board unit 9 has been described. However, the first and second cooling target portions are It is not limited to these.

1 is a diagram showing an external appearance of a projector that is an embodiment of the present invention. The figure which shows the internal structure of the projector of an Example. FIG. 2 is a diagram showing a part of the internal structure of the projector according to the embodiment. The figure which shows the metal plate for ground connection used for the projector of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper housing | casing 2 Lower housing | casing 4 Projection lens unit 5 Optical box 8 Lamp exhaust fan 9 Power supply board unit 10 Power supply exhaust fan 11 Signal board unit 12 Panel cooling fan 14 Lamp cooling fan 16 Sheet metal plate 16A Heat absorption part 16B Heat radiation part 17 Panel prism unit

Claims (4)

A first cooling target part;
A second cooling target part;
A cooling structure that cools the second cooling target part by sending air that has cooled the first cooling target part to the second cooling target part by a fan;
The cooling structure is
Each of the heat sinks is made of metal and absorbs heat from the air sent to the second cooling target by the fan, and a heat dissipator thermally connected to the heat absorber. Image projection device.   The image projection apparatus according to claim 1, wherein the heat absorption part and the heat radiation part are formed as an integral member.   The image projection apparatus according to claim 1, wherein the heat absorption unit constitutes at least a part of a duct that guides the air from the fan to the second cooling target unit. 4. The image projection apparatus according to claim 1, wherein the heat radiating unit is disposed along an inner surface of a housing of the image projection apparatus and functions as an electromagnetic shield member. 5.