JP2008191531A - Rear projector - Google Patents

Abstract

To provide a rear projector having a dustproof structure effective for cooling and preventing condensation.
A rear projector (1) converts light emitted from a light source unit into single polarized light by an integrator illumination unit (41), modulates the polarized light according to image information by a modulation optical unit, and expands the light onto a screen (20). The cooling frame 63, the optical unit housing 49 and the sirocco fan 61, which are the first sealed spaces that form the sealed space including the integrator illumination unit 41, and the sealed space including the modulation optical unit are formed. And a cooling mechanism for cooling the integrator illumination unit 41 and the modulation optical unit by circulating cooling air in the sealed space formed by the first sealed space and the second sealed space, respectively. The heat insulation layer part 64 for making a heat insulation state between the 1st sealed space part and the 2nd sealed space part is provided.
[Selection] Figure 9

Description

  The present invention relates to a rear projector having a dustproof structure.

  2. Description of the Related Art Conventionally, a rear projector has a cooling mechanism that cools an optical device that is also a heat generating unit with cooling air taken from the outside. In this cooling mechanism, dust may enter the rear projector together with the cooling air. The intruding dust floats in the light path from the light source to the screen due to the flow of the cooling air, and is projected along with the image on the screen. It was sometimes done. Therefore, as a method for preventing the intrusion of dust, a rear projector having a dustproof structure in which cooling air is not taken in from the outside, the inside of the rear projector is made a sealed space, and the cooling air is circulated in the sealed space is disclosed ( For example, Patent Document 1).

JP 2006-72138 A

  However, with the conventional technology, as the brightness of the light source increases, the amount of heat generated by the optical device arranged along the light path increases, and simply circulating the cooling air in a sealed space for dust prevention purposes. It is difficult to sufficiently cool these optical devices. As a countermeasure, it is effective to cool more strongly by using a cooling mechanism having a heat exchange function or the like so that the optical device having a large amount of heat generation is sufficiently cooled. In this case, the cooling mechanism having the heat exchange function is effective for cooling the optical device, but the temperature difference between the inside and outside of the rear projector is caused by the circulation of the cooling air strongly cooled by the heat exchange function or the like. As a result, there is a problem that condensation tends to occur.

  In order to solve the above problems, an object of the present invention is to provide a rear projector having a dustproof structure that is effective for cooling and preventing condensation.

  A rear projector according to the present invention modulates a light beam emitted from a light source in accordance with image information and projects it on a screen in an enlarged manner, and includes a sealed space portion formed so as to include a heat generating portion therein, and a sealed space. A cooling mechanism section for circulating the cooling air of the section to cool the heat generating section, and a heat insulating section for heat-insulating at least a part of the sealed space section and its periphery. To do.

  According to this rear projector, the sealed space is provided so as to include the heat generating portion therein, and the cooling mechanism portion is configured to cool the heat generating portion by circulating the cooling air inside the sealed space. In this configuration, if clean cooling air that does not contain dust or the like is sealed in the sealed space first, this clean cooling air circulates and cools the heat generating part. The situation that it is projected to. In addition, even if the cooling mechanism has the function of dissipating the heat of the heated cooling air to the outside and cooling the heat generating part more effectively, only the heat exchange is performed, The cooling air does not mix with the outside air, and there is no risk of intrusion of dust. Further, the rear projector has a heat insulating portion for preventing the adjacent portion from being cooled more than necessary due to the influence of the cooling air in the sealed space. With this heat insulation part, it is possible to perform original cooling corresponding to the heat generating part of the sealed space without considering the influence on the adjacent part and prevent the occurrence of condensation due to the temperature difference with the adjacent part etc. Is possible. With such a configuration, the rear projector can cool the heat generating portion while maintaining the dustproof property, and can prevent condensation due to a temperature difference and provide a stable image.

  The rear projector of the present invention converts a light beam emitted from a light source into a single polarized light by an integrator illuminating unit, modulates the polarized light according to image information by a modulation optical unit, and enlarges and projects it onto a screen. The first sealed space portion formed so as to include the integrator illumination portion therein, the second sealed space portion formed so as to include the modulation optical portion therein, the first sealed space portion, and the second sealed space A cooling mechanism for cooling the integrator illuminating unit and the modulation optical unit, and a heat insulating unit for providing a heat insulating state between the first sealed space unit and the second sealed space unit. And.

  According to this rear projector, the sealed space is formed so that the integrator illuminating unit and the modulation optical unit that generate heat by the light flux from the light source are provided inside, and the cooling mechanism unit cools the cooling air inside the sealed space. In this configuration, the integrator illumination unit and the modulation optical unit are cooled by circulation. In this configuration, if clean cooling air that does not contain dust or the like is first sealed in the sealed space, the clean cooling air circulates to cool the integrator illumination unit and modulation optical unit. And the like will not enter and be projected onto the screen. Furthermore, the first and second sealed spaces forming the sealed space of the rear projector are such that one of the cooling air is cooled more than necessary due to the influence of the temperature difference between the cooling air. In order to prevent this, it has a heat insulating part. That is, even if there is a mutual temperature difference, the heat insulation state is not affected. With this heat insulation part, it is possible to perform cooling at a unique cooling temperature in each sealed space without considering the influence of the mutual temperature difference, etc., and prevent the occurrence of condensation due to the mutual temperature difference Is possible. With such a configuration, the rear projector can cool the integrator illuminating unit and the modulation optical unit while maintaining dustproofness, and can prevent condensation due to a temperature difference between the first sealed space and the second sealed space. Therefore, it is possible to provide a stable video.

  In this case, the integrator illuminating unit preferably has an opening for allowing the cooling air to flow and pass in a direction substantially perpendicular to the traveling direction of the light flux.

  According to this configuration, the integrator illuminating unit for converting the light beam from the light source into a single polarized light to obtain a substantially uniform illuminance distribution increases the luminance of the light beam from the light source when the light beam is converted and passed. In response to this, the amount of heat generation increases and the temperature rises. Therefore, it is necessary to cool the lenses constituting the integrator illumination unit. The first sealed space that forms a sealed space including the integrator illuminating unit supplies cooling air from an opening provided in the integrator illuminating unit in order to cool these lenses. The opening is provided so that the cooling air flows along the lenses in a direction substantially perpendicular to the traveling direction of the light beam. Therefore, the cooling air does not flow to the modulation optical unit and the light source unit along the traveling direction of the light beam. In addition, the integrator lighting section is mainly cooled and circulated. Thus, by supplying cooling air to the integrator illumination unit through the opening, the integrator illumination unit can be effectively cooled.

  In this case, it is preferable that the 1st sealed space part has a heat radiating part for radiating heat outside and forcibly cooling the cooling air.

  According to this structure, the 1st sealed space part has a heat radiating part, and heat is forced by a heat radiating part from the cooling air which cooled the integrator illumination part which becomes a high temperature state according to the brightness | luminance increase of a light beam. It is possible to cool the integrator illuminating section more effectively by depriving it and circulating it. As described above, even if the closed space of the first sealed space portion is brought into a lower temperature state than the sealed space of the second sealed space portion and the integrator illumination portion is cooled strongly, the heat insulating portion causes the sealed space of the second sealed space portion to Does not affect temperature. Therefore, it is possible to perform a powerful cooling by providing a heat radiating part in the first sealed space and setting the sealed space of the first sealed space to a unique temperature setting.

  In this case, it is preferable that the cooling air in the second sealed space is circulated along the exterior casing and the screen constituting the second sealed space after cooling the modulation optical unit.

  According to this configuration, the cooling air that has cooled the modulation optical unit flows along the second sealed space including the outer casing and the screen. At this time, the cooling air dissipates heat to the outside through the exterior casing and the screen. Since the outer casing and the screen have a large area, if the cooling air circulates along the second sealed space, the outer casing and the screen are cooled to a temperature sufficient to cool the modulation optical unit again. In this way, by forming a large sealed space, it is possible to cool the modulation optical unit simply by circulating the cooling air.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. The rear projector in the embodiment forms a color image from an optical image obtained by modulating light (light beam) emitted from a light source according to image information, and enlarges and projects the color image on a screen via a reflection mirror. This rear projector has a dustproof property that dust does not enter the light path of the rear projector and an effective cooling property that prevents condensation.
(Embodiment)

  FIG. 1 is a perspective view showing an appearance of a rear projector as seen from the front side, and FIG. 2 is a perspective view showing an appearance of the rear projector as seen from the back side. As shown in FIG. 1 and FIG. 2, the exterior casing 10 that forms the exterior of the rear projector 1 is sequentially positioned on the leg exterior 11 that is a floor-mounted installation portion of the rear projector 1 and on the upper side of the leg exterior 11. A lower exterior 13 and an upper exterior 12, and a front exterior 14 provided on the front side of the upper exterior 12 are provided.

  The front exterior 14 has an opening formed in a rectangular shape, and a screen 20 is attached to the opening so as to close the opening. Further, the front exterior 14 has speaker boxes 22 on the left side and the right side, respectively.

  The lower exterior 13 has a woofer box 23 that accommodates a speaker that reproduces a low frequency range on the left and right sides of the front side, and a rear cover 10a cools a light source unit, which will be described later, as shown in FIG. The light source intake port 18 and the light source exhaust port 19 for sucking and exhausting the cooling air for cooling, and the rear heat radiating unit 21 for radiating the heat of the cooling air for cooling the integrator illuminating unit described later are included. These intake / exhaust ports will be described later with reference to FIG.

  The upper exterior 12 has a triangular shape when viewed from the side, a boundary surface portion 15 that forms a boundary with the lower exterior 13, and left and right side surface portions 16 that are triangular plates that are erected from both ends of the boundary surface portion 15, And a back surface portion 17 that is a slope straddling these left and right side surface portions 16.

  Next, the internal configuration of the rear projector 1 will be briefly described. FIG. 3 is a cross-sectional view showing the internal configuration of the rear projector as viewed from the side. As shown in FIG. 3, an optical unit 40 that emits light including an optical image provided on the leg exterior 11 side of the lower exterior 13 and an optical unit 40 are placed inside the rear projector 1. The adjusting mechanism 48 that adjusts the direction of light emitted from the optical unit 40 and the back surface of the upper exterior 12 so as to face the optical unit 40 and the screen 20, are emitted from the projection optical unit 45 of the optical unit 40. And a reflection mirror 25 for reflecting the reflected light to the screen 20 is accommodated.

  In this configuration, since the light emitted from the optical unit 40 to the reflection mirror 25 is in a wide angle state, it travels as indicated by the light path L, and is reflected by the reflection mirror 25 and reaches the screen 20. The image is enlarged and projected on the entire surface of the screen 20. In addition to the optical unit 40 and the adjustment mechanism unit 48, the lower exterior 13 includes a power supply unit (not shown), a control unit that controls the optical unit 40, and the interior of the rear projector 1 including the optical unit 40 by cooling air. The cooling mechanism part etc. which cool are accommodated.

  FIG. 4 is a perspective view showing the external appearance of the optical unit, and is a view of the optical unit viewed from obliquely above. The optical unit 40 optically processes light emitted from a light source lamp, which is a light source, to form an optical image corresponding to image information, and a color image obtained by synthesizing the optical image is reflected on the reflection mirror 25 shown in FIG. And a unit for enlarging and projecting to the screen 20. As shown in FIG. 4, the optical unit 40 includes a light source unit 46, an integrator illumination unit (heat generation unit) 41, a color separation optical unit 42, a relay optical unit 43, and a modulation optical unit (heat generation) in the order of traveling light. Part) 44 and a projection optical part 45. In this case, in the optical unit 40, light is emitted from the light source unit 46, bent, travels in the direction of the projection optical unit 45, and is emitted from the projection optical unit 45 toward the reflection mirror 25. Each part of the optical unit is integrally held by an optical unit housing 49.

  Further, the cooling of the optical unit 40 includes the modulation unit cooling flow A that is a flow of cooling air that mainly cools the modulation optical unit 44, the light source unit cooling flow B that mainly cools the light source unit 46, and the integrator illumination unit 41. This is performed by three cooling flows, namely, an integrator cooling flow C for cooling the air. The optical unit 40 is provided around the projection optical unit 45 and has an intake frame 50 having an opening for taking in cooling air from above, which is the light emission direction side, and the cooling air provided below the projection optical unit 45. And a sirocco fan 52 for sucking air into the intake frame 50. The cooling air sucked into the fan intake port 52a of the sirocco fan 52 cools the modulation optical unit 44 to form a modulation unit cooling flow A. In this case, the intake frame 50 and the sirocco fan 52 are cooling mechanisms. Details of the modulation unit cooling flow A will be described later with reference to FIG.

  The optical unit 40 has a sirocco fan 53 below the light source unit 46. The sirocco fan 53 sucks cooling air from the light source inlet 18 shown in FIG. 2 and blows it to the light source unit 46. Then, the light source part cooling flow B exhausted from the light source exhaust port 19 through the exhaust duct part 54 is formed. Details of the light source unit cooling flow B will be described later with reference to FIG.

Furthermore, the optical unit 40 has an integrator cooling unit 60 for cooling the integrator illumination unit 41. The integrator cooling unit 60 includes a sirocco fan 61 that sucks cooling air from an upper opening (opening) 416 provided on the upper side of the optical unit housing 49 of the integrator lighting unit 41, and the integrator lighting unit 41 from the sirocco fan 61. The cooling frame 63 for guiding and circulating the cooling air to the lower opening (opening) 417 provided on the lower side of the cooling frame 63 and the heat of the cooling air circulating inside the cooling frame 63 And a heat insulating layer (heat insulating portion) 64 that covers the optical unit housing 49 of the integrator lighting unit 41, the outer periphery of the sirocco fan 61, and the cooling frame 63. is doing. The heat insulating layer portion 64 is a paint in which ceramic beads are mixed in an epoxy resin, and is applied to the optical unit casing 49, the outer periphery of the sirocco fan 61, and the cooling frame 63.
The cooling air inside the integrator cooling unit 60 forms an integrator cooling flow C that cools and circulates the integrator illumination unit 41. In this case, the sirocco fan 61, the Beltier element 62, and the cooling frame 63 are the cooling mechanism. Details of the integrator cooling flow C will be described later with reference to FIG.

  Next, the optical unit 40 that is the backbone of the rear projector 1 will be described in detail. FIG. 5 is a schematic view showing details of the inside of the optical unit. First, the light source unit 46 will be described in order. The light source unit 46 includes a light source lamp 462 that is a light source and a reflector 463 as the light source device 461, and a radial light beam emitted from the light source lamp 462 is reflected by the reflector 463 that is a parabolic mirror so as to be parallel. Ejected as light rays. In this case, a halogen lamp is used as the light source lamp 462. In addition to the halogen lamp, a metal halide lamp, a high-pressure mercury lamp, or the like may be employed.

  The integrator illumination unit 41 is for making the illuminance distribution of light from the light source substantially uniform. Specifically, the light source unit 46 is an optical system having lenses for illuminating an optical image forming region of the three liquid crystal panels 441 (441R, 441G, 441B) constituting the modulation optical unit 44 almost uniformly. A first lens array 412, a second lens array 413, a polarization conversion element 414, and a superimposing lens 415 are provided in this order from the side.

  Here, as shown in FIG. 5, the first lens array 412 and the superimposing lens 415 of the integrator illuminating unit 41 are attached to the optical unit housing 49 so as to separate the light from the light source unit 46. Although it is allowed to pass through the optical unit 42, the cooling air of the integrator cooling flow C is configured not to flow to the light source unit 46 or the color separation optical unit 42. Further, the optical unit housing 49 of the integrator illumination unit 41 is provided with a heat insulating layer part 64 similar to the heat insulating layer part 64 provided in the cooling frame 63 shown in FIG.

  Although not shown in detail, the first lens array 412 has a configuration in which small lenses having a substantially rectangular outline as viewed from the optical axis direction are arranged in a matrix. These small lenses are for dividing the light emitted from the light source device 461 into a plurality of partial lights, and the contour shape of each small lens is substantially similar to the shape of the optical image forming region of the liquid crystal panel 441. It is set to make. For example, if the aspect ratio of the optical image formation region of the liquid crystal panel 441 (the ratio between the horizontal and vertical dimensions) is 16: 9, the aspect ratio of each small lens is also set to 16: 9.

  The second lens array 413 has substantially the same configuration as the first lens array 412, and has a configuration in which small lenses are arranged in a matrix. The second lens array 413, together with the superimposing lens 415, functions to form an optical image of each small lens of the first lens array 412 on the liquid crystal panel 441.

  The polarization conversion element 414 is disposed between the second lens array 413 and the superimposing lens 415 and is unitized with the second lens array 413. Such a polarization conversion element 414 is for converting the light from the second lens array 413 into one kind of polarized light, and thus it is possible to increase the light use efficiency in the modulation optical unit 44. It is.

  More specifically, each partial light converted into one type of polarized light by the polarization conversion element 414 is finally superimposed on the liquid crystal panel 441 of the modulation optical unit 44 by the superimposing lens 415. In the rear projector 1 using the liquid crystal panel 441 of the type that modulates polarized light, only one type of polarized light can be used, so almost half of the light from the light source lamp 462 that emits other types of randomly polarized light is not used. For this reason, by using the polarization conversion element 414, all the light from the light source lamp 462 is converted into one type of polarized light, and the light use efficiency in the modulation optical unit 44 is enhanced.

  The polarized light converted by the integrator illumination unit 41 proceeds to the color separation optical unit 42. The color separation optical unit 42 includes two dichroic mirrors 421 and 422 and a reflection mirror 423. The dichroic mirrors 421 and 422 convert polarized light, which is a plurality of partial lights emitted from the integrator illumination unit 41, into red light. (R), green (G), and blue (B) have a function of separating into three color lights.

  The relay optical unit 43 includes an incident side lens 431, a pair of relay lenses 433, and reflection mirrors 432 and 434. In this case, red light that is color light separated by the color separation optical unit 42 is liquid crystal. It is for leading to the panel 441R.

  At this time, the dichroic mirror 421 of the color separation optical unit 42 transmits the red light and the green light emitted from the integrator illumination unit 41, and reflects the blue light. The blue light reflected by the dichroic mirror 421 is reflected by the reflection mirror 423, passes through the field lens 418, and reaches the blue liquid crystal panel 441B. The field lens 418 converts each partial light emitted from the second lens array 413 into light parallel to the central axis of the field lens 418. The field lenses 418 provided in the other liquid crystal panels 441G and 441R have the same function.

  Of the red light and green light transmitted through the dichroic mirror 421, the green light is reflected by the dichroic mirror 422, passes through the field lens 418, and reaches the liquid crystal panel 441G for green. On the other hand, the red light passes through the dichroic mirror 422, passes through the relay optical unit 43, passes through the field lens 418, and reaches the liquid crystal panel 441R for red light. The reason why the relay optical unit 43 is used for red light is to prevent light attenuation and the like because the optical path length of red light is longer than the optical path lengths of other color lights. In other words, the partial light incident on the incident side lens 431 is allowed to reach the field lens 418 as it is. It is also possible to use a configuration that guides blue light to the relay optical unit 43.

  Next, the modulation optical unit 44 modulates and synthesizes each incident color light according to image information to form a color image, and each color light separated by the color separation optical unit 42 enters 3 Two incident-side polarizing plates 442, liquid crystal panels 441R, 441G, 441B, which are light modulation devices disposed downstream of the respective incident-side polarizing plates 442, and emission sides disposed downstream of the respective liquid crystal panels 441R, 441G, 441B. A polarizing plate 443 and a cross dichroic prism 444 which is a color composition device are provided.

  In this case, the liquid crystal panel 441 is of a transmission type using a polysilicon TFT as a switching element. The incident-side polarizing plate 442 transmits only polarized light in a certain direction and absorbs other light out of each color light separated by the color separation optical unit 42, and is applied to a polarizing film on a substrate such as sapphire glass. Is affixed. The exit-side polarizing plate 443 is configured in substantially the same manner as the incident-side polarizing plate 442, and transmits only polarized light in a predetermined direction and absorbs other light out of the light emitted from the liquid crystal panel 441. In the liquid crystal panel 441, since the incident polarized light is twisted and emitted at a right angle, the incident-side polarizing plate 442 and the emission-side polarizing plate 443 are set so that the directions of the polarization axes thereof are orthogonal to each other.

  The cross dichroic prism 444 combines the optical images emitted from the emission-side polarizing plate 443 and modulated for each color light to form a color image. The cross dichroic prism 444 is provided with a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light in a substantially X shape along the interface of four right-angle prisms. The three color lights are combined by the multilayer film to form a color image.

  Next, the color image formed by the modulation optical unit 44 is emitted to the reflection mirror 25 shown in FIG. The projection optical unit 45 includes a projection lens unit 451 and a right-angle prism 452. The right-angle prism 452 is disposed on the light emission side of the cross dichroic prism 444 of the modulation optical unit 44, and reflects the color image synthesized by the cross dichroic prism 444 by bending it toward the projection lens unit 451. The projection lens unit 451 includes a plurality of optical lenses, and emits the color image reflected by the right-angle prism 452 to the reflection mirror 25 so as to be enlarged.

  Next, the arrangement of the optical unit 40 in the outer casing 10 and the modulation unit cooling flow A, the light source unit cooling flow B, and the integrator cooling flow C for cooling the optical unit 40 will be described. FIG. 6 is a perspective view showing a flow of cooling air for cooling the optical unit. When viewed from the side, the optical unit 40 is accommodated in the lower portion of the lower exterior 13 as shown in FIG. Further, when viewed from the back side of the lower exterior 13, as shown in FIG. 6, the light source portion 46 is positioned on one side of the side surface portion 16, and the intake frame 50 is positioned at a substantially central portion of the lower exterior 13. So that it is housed.

  In the exterior casing 10, when the optical unit 40 is accommodated in the lower exterior 13 and the attachment / detachment cover 13 a is attached, the internal space other than the flow path of the light source unit cooling flow B becomes a sealed space. Further, in the internal space, the modulation unit cooling flow A and the integrator cooling flow C are separate sealed spaces. In each of the sealed spaces, the cooling air cools the integrator illumination unit 41 and the modulation optical unit 44 of the optical unit 40 along the light path L. Further, the Beltier element 62 of the integrator cooling unit 60 is positioned to face the rear heat radiation unit 21 of the attachment / detachment cover 13a.

  Of these three cooling flows, the modulation unit cooling flow A for cooling the modulation optical unit 44 will be described first. FIG. 7 is a cross-sectional view showing a flow of cooling air for cooling the modulation optical unit. The interior of the exterior housing 10 is partitioned from the lower exterior 13 by a boundary surface portion 15 of the upper exterior 12, and the boundary surface 15 circulates with a circulation inlet 15 a for circulating cooling air between the upper exterior 12 and the lower exterior 13. And an outlet 15b.

  The circulation inlet 15a is provided so as to coincide with the opening of the upper part of the intake frame 50 of the optical unit 40, and the cooling air in the upper exterior 12 sequentially passes through the circulation inlet 15a and the intake frame 50. Passed through and sucked into the sirocco fan 52. The cooling air sucked into the sirocco fan 52 flows under the optical unit 40, mainly cools the modulation optical unit 44 and is discharged from the optical unit 40 into the lower exterior 13. The discharged cooling air flows to the inside of the upper exterior 12 through the circulation outlet 15 b of the boundary surface portion 15. The interior of the upper exterior 12 is a wide space that is surrounded by each surface portion of the screen 20 and the upper exterior 12 and is also a light path L. Cooling air that has been warmed by cooling the optical unit 40 flows through this space, Heat is released to the outside through the surface portions 20 and the upper exterior 12. And it again circulates from the circulation inlet 15a to the lower exterior 13 side.

  In this case, it is preferable that the cooling air circulates through the upper exterior 12 without any problem. For this reason, the cooling air sucked from the circulation inlet 15a located in the substantially central part is a duct (not shown) extending from the circulation inlet 15a to the one side part 16 so as to be taken in from the vicinity of the one side part 16. Led by. The circulation inlet 15a and the sirocco fan 52 are also connected by a dedicated duct 15c (not shown). The modulation optical unit 44 and the circulation outlet 15b are also connected by a duct 15d. Thereby, the modulation | alteration part cooling flow A circulates through the inside of the upper exterior 12 to every corner.

  Such a modulation unit cooling flow A is a flow of cooling air that circulates in the sealed space formed by the inner surface of the exterior casing 10 as the second sealed space portion and the screen 20. Therefore, by first assembling the exterior housing 10 in a clean room and removing dust from the cooling air, it is possible to prevent the color image of the screen 20 from being affected by dust thereafter.

  Next, the light source part cooling flow B for cooling the light source part 46 will be described. FIG. 8 is a cross-sectional view showing a flow of cooling air for cooling the light source unit. As shown in FIG. 8, the sirocco fan 53 located at the lower part of the light source part 46 is connected to the light source inlet 18 provided in the attachment / detachment cover 13a, and the exhaust duct part 54 provided at the upper part of the light source part 46 is The light source exhaust port 19 provided in the attachment / detachment cover 13a is connected. With such a configuration, the cooling air that cools the light source unit 46 is sucked into the sirocco fan 53 from the outside of the exterior housing 10 through the light source inlet 18, and from the sirocco fan 53 to the light source device 461 of the exhaust light source unit 46. Supplied. The cooling air that has cooled the light source device 461 and exchanged heat is exhausted from the light source exhaust port 19 through the exhaust duct portion 54.

  Unlike the flow of the modulation unit cooling flow A that circulates inside the exterior housing 10, such a light source unit cooling flow B flows in communication with the outside via the light source intake port 18 and the light source exhaust port 19. In the rear projector 1, only the light source unit 46 that generates the largest amount of heat is strongly cooled. Since the light source unit 46 is less affected by dust and the like than the integrator illumination unit 41 and the modulation optical unit 44, the cooling effect can be given priority by introducing cooling air from the outside. Although not shown, the light source inlet 18 is provided with an air filter and takes in cooling air from which dust and the like are substantially eliminated.

  Next, an integrator cooling flow C for cooling the integrator illumination unit 41 will be described. FIG. 9 is a cross-sectional view showing a flow of cooling air for cooling the integrator illumination unit. As shown in FIG. 9, the integrator cooling flow C is a cooling air that circulates in the sealed space formed by the optical unit housing 49, the sirocco fan 61, and the cooling frame 63 of the integrator illumination unit 41 as the first sealed space. It is the flow of.

  In the sealed space formed by the first sealed space, the cooling air is sucked by the sirocco fan 61 from the upper opening 416 provided in the optical unit housing 49 of the integrator illumination unit 41. The sucked cooling air is in a state in which the lenses of the integrator lighting unit 41 are cooled and warmed, and is discharged through the sirocco fan 61 toward the Beltier element 62 of the cooling frame 63. At this time, the Beltier element 62 takes heat from the cooling air and dissipates the heat to the outside through the rear heat radiation portion 21 of the attachment / detachment cover 13a. Therefore, the integrator cooling flow C is cooled to a low temperature by the action of the Beltier element 62. Cooling air cooled by the Bercher element 62 is supplied to the integrator illumination unit 41 from the lower opening 417. As described above, in the first sealed space, even the lenses of the integrator illumination unit 41 that is close to the light source unit 46 and has a high temperature can be sufficiently cooled by the sufficiently cooled cooling air.

  Here, the Beltier element 62 will be briefly described. The Beltier element 62 is obtained by joining two kinds of metals, and applies a so-called Beltier effect in which heat is transferred from one metal to the other when an electric current is passed through the junction. In order to remove the heat from the cooling air, the Bertier element 62 is attached to the cooling frame 63 by arranging one heat absorption side metal on the closed space side and the other heat radiation side metal on the rear heat radiation part 21 side. To place. The rear heat radiation portion 21 serves as a heat sink, and is provided to efficiently dissipate the heat taken by the Belletier element 62 from the cooling air to the outside of the rear projector 1.

  Thus, the integrator cooling flow C in the first sealed space portion flows through the cooling air sufficiently cooled by the Beltier element 62. Therefore, when there is no heat insulation layer portion 64, the optical unit housing 49 that forms the sealed space, Through the sirocco fan 61 and the cooling frame body 63, the temperature of the cooling air of the modulation section cooling flow A flowing around the cooling frame body 63 and the like is affected. When the modulation part cooling flow A is mixed with cooling air having a temperature difference, condensation easily occurs in the sealed space formed by the second sealed space. Further, also in the exterior casing 10 and the screen 20 which are the second sealed space portion, the temperature difference between the inside and outside is enlarged, and condensation is likely to occur.

  In the rear projector 1, the heat insulating layer 64 is provided so as to cover the optical unit housing 49, the sirocco fan 61, and the cooling frame 63 in the first sealed space, thereby affecting the temperature of the air around the cooling frame 63. Has a setting that does not reach the sealed space. Further, the cooling air of the integrator cooling flow C is not heated by the air around the optical unit housing 49, the sirocco fan 61, and the cooling frame 63 by providing the heat insulating layer portion 64. The cooling efficiency can be increased, and the integrator illumination unit 41 can be cooled more powerfully.

  The effects in the embodiment described above will be described together.

  The rear projector 1 includes two sealed spaces for circulating the modulation unit cooling flow A and the integrator cooling flow C for cooling the modulation optical unit 44 and the integrator illumination unit 41, which are heat generation units, and maintains dust resistance. However, it is possible to optimally cool the modulation optical unit 44 and the integrator illumination unit 41, respectively.

  Moreover, the 1st sealed space part which forms the sealed space for the integrator cooling flow C to circulate has the Bertier element 62, and cools the cooling air of the integrator cooling flow C strongly. The Beltier element 62 can efficiently cool the integrator illumination unit 41 that is close to the light source unit 46 and generates a large amount of heat.

  In addition, the first sealed space is covered with the heat insulating layer 64 and prevents the sufficiently cooled integrator cooling flow C from affecting the modulation unit cooling flow A, and thus is caused by a temperature difference. It is possible to prevent the occurrence of easy condensation. As a result, the rear projector 1 can prevent condensation in addition to excellent dustproof and cooling properties, can provide a clear image for a long period of time, and can extend the product life.

  Further, the present invention is not limited to the above-described embodiment, and the same effects as those of the embodiment can be obtained even in the form of the following modification.

  The first sealed space portion and the second sealed space portion form a sealed space in which the first sealed space portion includes the modulation optical unit 44, and the second sealed space portion forms a sealed space including the integrator illumination unit 41. The setting may be different from the embodiment in which the optical unit 44 and the integrator illumination unit 41 are optimally cooled.

  Further, in the light source unit cooling flow B for cooling the light source unit 46, the cooling air is circulated in the sealed space in the same manner as the modulation unit cooling flow A and the integrator cooling flow C without taking in cooling air from the outside. Also good. Although the light source unit 46 is hardly affected by dust or the like, it is possible to make the dustproof property of the optical unit 40 almost perfect.

  The modulation portion cooling flow A is sucked into the sirocco fan 52 from the circulation inlet 15a of the boundary surface portion 15 via the intake frame 50. However, the configuration may be such that the intake frame 50 is omitted. . However, if the intake frame 50 is used as in the embodiment, the modulation portion cooling flow A is circulated to every corner of the upper exterior 12 and the temperature of the cooling air in the exterior housing 10 is prevented from being uneven. From the viewpoint of preventing condensation.

  Furthermore, it is not limited to using the Beltier element 62 as a heat radiating part, and a compressor system or the like may be used. If the Beltier element 62 is used as in the embodiment, more excellent effects can be obtained in terms of space saving and power saving.

  In the rear projector 1, the modulation optical unit 44 uses a transmissive liquid crystal panel 441 having a light incident surface and a light exit surface different from each other, but a reflection type liquid crystal panel having the same light incident surface and the light exit surface. May be used. Furthermore, the present invention is not limited to using the liquid crystal panel 441, and a light modulation element other than liquid crystal such as a device using a micromirror may be used. Thus, the present invention can be applied to various types of rear projectors, and the application range can be expanded.

The perspective view which shows the external appearance which looked at the rear projector from the front side. The perspective view which shows the external appearance which looked at the rear projector from the back side. Sectional drawing which shows the internal structure which looked at the rear projector from the side surface side. The perspective view which shows the external appearance of an optical unit. The schematic diagram which shows the detail inside an optical unit. The perspective view which shows the flow of the cooling air which cools an optical unit. Sectional drawing which shows the flow of the cooling air which cools a modulation optical part. Sectional drawing which shows the flow of the cooling air which cools a light source part. Sectional drawing which shows the flow of the cooling air which cools an integrator illumination part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Rear projector, 10 ... Exterior housing, 11 ... Leg exterior, 12 ... Upper exterior, 13 ... Lower exterior, 14 ... Front exterior, 15 ... Boundary surface part, 15a ... Circulation inlet, 15b ... Circulation outlet, 18 DESCRIPTION OF SYMBOLS ... Intake port for light sources, 19 ... Exhaust port for light sources, 20 ... Screen, 21 ... Back surface heat radiation part, 25 ... Reflection mirror, 40 ... Optical unit, 41 ... Integrator illumination part as a heating part, 44 ... Modulation as a heating part Optical part 49 ... Optical unit housing 50 ... Intake frame 52,53 ... Sirocco fan 52a ... Fan air inlet 54 ... Exhaust duct part 60 ... Integrator cooling part 61 ... Sirocco fan 62 ... Heat radiation ,..., A cooling frame, 64... Heat insulating layer, 416... Upper opening, 417... Lower opening, A. Integrator cooling flow.

Claims (5)

A rear projector that modulates a light beam emitted from a light source according to image information and projects an enlarged image onto a screen,
A sealed space formed so as to include the heat generating portion therein;
A cooling mechanism for cooling the heat generating part by circulating cooling air in the sealed space,
A rear projector, comprising: a heat insulating portion for making at least a part of the sealed space portion and its periphery a heat insulating state. A rear projector that converts a light beam emitted from a light source into a single polarized light by an integrator illumination unit, modulates the polarized light according to image information by a modulation optical unit, and projects an enlarged image onto a screen,
A first sealed space formed so as to include the integrator illumination unit therein;
A second sealed space formed so as to include the modulation optical unit therein;
A cooling mechanism for cooling the integrator illumination unit and the modulation optical unit by circulating cooling air of the first sealed space and the second sealed space, respectively;
A rear projector, comprising: a heat insulating portion for providing a heat insulating state between the first sealed space portion and the second sealed space portion. The rear projector according to claim 2,
The rear projector, wherein the integrator illuminating unit has an opening for allowing the cooling air to flow and pass in a direction substantially perpendicular to the traveling direction of the light beam. The rear projector according to claim 2 or 3,
The rear projector according to claim 1, wherein the first sealed space has a heat radiating portion for radiating heat to the outside and forcibly cooling the cooling air. The rear projector according to any one of claims 2 to 4,
The rear projector, wherein the cooling air in the second sealed space part circulates along the exterior casing and the screen constituting the second sealed space part after cooling the modulation optical part.

Images