JP2005345821A - projector - Google Patents

Abstract

A projector capable of sufficiently cooling an optical device without hindering downsizing is provided.
A projector including an optical device having a light modulation device that modulates a light beam emitted from a light source according to image information to form an optical image, and introducing cooling air from the outside. 511R, 511G, and 511B are arranged to face the fan, the other openings 512R, 512G, and 512B face the light modulator, and a duct 500 that guides the cooling air introduced from the fan to the light modulator, and the other of the duct 500 A heat radiating member 55 made of a heat conductive material is provided in the vicinity of the openings 512R, 512G, and 512B according to the arrangement of the light modulation device and connected to the optical device so as to be capable of heat conduction.
[Selection] Figure 5

Description

  The present invention relates to a projector including an optical device having a light modulation device that modulates a light beam emitted from a light source according to image information to form an optical image, and a fan that introduces cooling air from the outside.

2. Description of the Related Art Conventionally, a projector that modulates a light beam emitted from a light source in accordance with image information and enlarges and projects an optical image has been used.
Specifically, a color separation optical system that separates the light emitted from the light source lamp into red, green, and blue color light using a dichroic mirror, and the separated light according to image information for each color light An optical device having three liquid crystal panels (light modulation devices) to be modulated and a cross dichroic prism (color combining optical device) for combining light beams modulated by the liquid crystal panels, and a color optical image formed by the optical device A three-plate projector or the like having a projection lens for enlarging and projecting the image on a screen is known.
On the other hand, a single-plate projector that uses a color filter to form a color image with only one liquid crystal panel is also known.

In recent years, such projectors have been increasingly used for presentations at conferences, academic meetings, exhibitions, home theaters, and the like, and further miniaturization and higher brightness have been promoted. Along with this, the temperature of optical components such as liquid crystal panels of optical devices, polarizing plates, retardation plates, and various filters whose life greatly depends on heat is also increasing. In addition, how to cool the optical device is more important than ever.
Conventionally, as a cooling means of this optical device, an air cooling method has been adopted in which a fan and a duct are provided, and air sent from the fan is introduced into the optical device through the duct.

On the other hand, as in Patent Document 1, the light source lamp, the incident side polarizing plate, etc. are covered with a metal case having good thermal conductivity, and the heat generated by the lamp, the polarizing plate, etc. is radiated and cooled through this case. Some have improved cooling performance.
Further, as in Patent Document 2, an optical device including a liquid crystal panel, a polarizing plate, and the like is accommodated in a case, and the case, a fan, and a hollow member provided in the vicinity of a vent of the projector housing are provided with 3 Some hoses are connected to form a closed circulation system, and air is circulated in the system while cooling the heat from the hollow fins and the radiation fins formed on the surface of the hose.
Furthermore, as in Patent Document 3, a liquid crystal panel and a cross dichroic prism are sealed together with a liquid refrigerant in a case made of metal and glass, and a radiator and an electronic cooling element in which a plurality of fins are formed are provided in the case. Some cool the optical device by blowing air to the radiator and by the action of an electronic cooling element.

Japanese Utility Model Publication No. 7-23330 ([0009] [0011], FIG. 1) Japanese Patent Laid-Open No. 2001-42435 ([0017] to [0020], FIG. 3) JP-A-10-239774 ([0008], FIG. 1)

However, in the configuration as in Patent Document 1, the size of the case that accommodates the light source lamp and the incident-side polarizing plate is limited due to the miniaturization of the projector, and this case must be considerably small. Therefore, a sufficient cooling effect cannot be obtained if the heat of the light source lamp, the polarizing plate, etc. is radiated through this case, and the recent demand for higher brightness of the projector cannot be met.
On the other hand, in the configuration as in Patent Document 2, the number of parts such as a hollow member and a plurality of hoses is large, and the optical device and the projector are downsized due to the complexity of the structure in which the hose is connected to the case to form a sealed space. Is difficult.
Further, in the configuration as in Patent Document 3, a member dedicated to cooling such as an electronic cooling element or a radiator provided in the case of the optical device is used, and even though sufficient cooling performance corresponding to the cost can be obtained, Providing a radiator etc. will also hinder downsizing.

  In view of the above problems, an object of the present invention is to provide a projector capable of sufficiently cooling an optical device without hindering downsizing.

The present invention is a projector comprising an optical device having a light modulation device that modulates a light beam emitted from a light source according to image information to form an optical image, and a fan for introducing cooling air from the outside, One opening is disposed opposite to the fan, the other opening faces the light modulation device, and a duct that guides cooling air introduced from the fan to the light modulation device,
A heat dissipating member made of a heat conductive material provided near the other opening of the duct and in accordance with the arrangement of the light modulation device and connected to the optical device so as to be capable of heat conduction is provided. And

Here, an injection molded product made of a synthetic resin material or the like can be adopted as the duct. Further, the direction of the duct extending from the position of the fan to the optical device is not limited, and the direction may be bent and changed in the middle.
Further, as the heat radiating member, a plate member formed of aluminum, magnesium, titanium, copper, iron, an alloy thereof, or a heat conductive resin can be adopted, and the heat radiating member is an optical device side opening of the duct. It is provided at a position where the opening is secured.
Various fans, such as sirocco fans and axial fans, can be used.

According to the present invention, the cooling air is sent to the optical device through the duct to cool the optical device, and the heat of the optical device is conducted to the heat radiating member and radiated from the heat radiating member to the outside. . At this time, the heat radiating member serving as the heat sink of the optical device is exposed to the air led out from the opening of the duct and directly cooled, so that air cooling and heat radiative cooling are performed synergistically, and the optical modulation provided in the optical device The apparatus and the optical elements in the vicinity thereof can be sufficiently and efficiently cooled.
Furthermore, the size, position, and shape of the opening of the duct can be changed depending on the position and shape of the heat radiating member. The wind direction can be adjusted. For example, if the opening of the duct is narrowed by the heat radiating member, the wind speed is increased, and the optical components arranged in the vicinity of the opening can be intensively cooled. On the other hand, if the opening of the duct is widened, the wide area can be uniformly cooled.
On the other hand, since the heat radiating member constituting the heat radiating mechanism is provided in the duct constituting the air cooling mechanism, a space burden more than that of the duct occupying a certain range is not generated in the apparatus in which the optical device is incorporated. Further, the optical device can be supported and held by utilizing the arrangement of the duct, such as placing the optical device on the duct, and it is not necessary to separately prepare a support / holding member for the optical device.
Therefore, a projector having sufficient cooling performance can be provided without hindering downsizing. In addition, since the temperature of the optical device can be reduced, the reliability can be improved.

The opening of the duct facing the optical device is preferably oriented in a direction substantially along the surface of the image forming area where the light modulation of the light modulation device is performed.
As a result, air derived from the opening of the duct can be blown in a direction substantially along the surface of the image forming area, and the entire image forming area can be uniformly cooled, and the color unevenness of the optical image formed by the light modulation device can be reduced. Can be prevented.

In this invention, it is preferable that the said heat sink extends along the side surface of the said duct.
Here, the opening on the optical device side of the duct may be an end surface opening when the duct is a cylindrical body, or may be an opening formed on the side surface of the duct. The heat radiating member extends along the side surface of the duct while ensuring the opening of the opening of the duct.
Further, when the heat radiating member is formed in a plate shape, the heat radiating member can be easily disposed along the side surface of the duct if the cross-sectional shape of the duct is rectangular or the like.
According to such a configuration, it is easy to ensure a large area of the heat radiating member along the side surface of the duct that occupies a certain range in the device in which the optical device is incorporated, and the heat radiating performance can be easily improved.

  In the present invention, a color separation optical system that separates a light beam emitted from the light source into a plurality of color lights is provided, and the optical device modulates each color light separated by the color separation optical system to form an optical image. A plurality of light modulation devices, and a color combining optical device that has a plurality of light beam incident end faces facing the light modulation devices and combines optical images formed by the light modulation devices, It is preferable that the light is branched inside according to a plurality of light modulation devices, and the other opening faces each of the light modulation devices.

Here, a cross dichroic prism or the like can be adopted as the color synthesis optical device.
According to this invention, similar to the above invention, the optical device can be efficiently and sufficiently cooled by the synergistic effect of the air cooling mechanism and the heat dissipation mechanism, and the heat dissipation mechanism is provided in the duct, so that downsizing is hindered. There is nothing to do.
In addition, the plurality of light modulators and the optical elements in the vicinity thereof are cooled by the branch of the duct, so the amount of air blown from the opening of the duct, the wind pressure, etc. depending on the temperature difference of each light modulator. By appropriately changing the above, it becomes possible to average the temperatures of the respective light modulation devices and sufficiently cool them.
In addition, since the duct branches according to a plurality of light modulation devices that can be cooled, the number of parts does not increase.

In the present invention, it is preferable that the duct extends in the vicinity of one end surface intersecting with the plurality of light beam incident end surfaces of the color combining optical device.
Here, when the color synthesizing optical device is a cross dichroic prism and the light modulation device is arranged on three side surfaces thereof, the “one end surface intersecting with the plurality of light beam incident end surfaces” is the upper and lower end surfaces. Has a plurality of ducts extending in the vicinity of one of the upper and lower end surfaces.
With such a configuration, the positions of the opening portions of the ducts facing the light modulation device are aligned according to the branching of the duct, and the air guided by the ducts flows out from these opening portions in substantially the same direction. Contributes to internal rectification.

In the present invention, it is preferable that a hole is formed in the heat dissipation member at a position corresponding to the other opening of the duct.
According to the present invention, the hole of the heat radiating member corresponds to the other opening of the duct, and by changing the shape, size, and position of the hole, the wind pressure, the air volume, and the wind direction of the air derived from the duct are appropriately adjusted. In addition, since the peripheral edge of the hole comes into contact with the air led out from the duct, the heat radiating member serving as the heat sink of the optical device is sufficiently cooled.

In the present invention, the light modulation device includes a light modulation element that performs light modulation, a peripheral edge of the light modulation element in a state of being thermally conductive with the light modulation element, and extending along the flow of the cooling air. Preferably, the heat dissipation member is connected to the holding frame so as to be capable of conducting heat.
According to the present invention, the heat of the light modulation element whose temperature has been increased by the light irradiation is quickly conducted to the heat radiating member through the holding frame, and the holding frame is exposed to the air flow, so that the heat of the light modulation element is directly The conductive holding frame is efficiently cooled. As a result, the life of the light modulation device can be extended.
The optical device includes an optical conversion element that performs optical conversion of the light beam modulated by the light modulation device, a peripheral edge of the optical conversion element in a state of being thermally conductive with the optical conversion element, and the cooling. It is preferable that the heat dissipation member is connected to the holding member so as to be capable of conducting heat.
Here, as the optical conversion element, a polarizing plate, a viewing angle correction plate, a retardation plate, or the like can be adopted.
According to the present invention, the heat of the optical conversion element whose temperature has been increased by the heat of absorption of light is quickly conducted to the heat dissipation member via the holding member, and the holding member is exposed to the air flow, so that the heat of the optical conversion element is The directly conducting holding member is efficiently cooled. As a result, the life of the optical conversion element can be extended.

In this invention, it is preferable that the said holding frame and / or the said holding member, and the said heat radiating member are connected by the connection member which has flexibility and heat conductivity.
According to the present invention, the connection member ensures the heat conductive connection between the heat radiating member and the light modulation device or the optical conversion element, and further improves the cooling efficiency with the light modulation device or the optical conversion element as the center. it can.

In the present invention, at the end of the holding frame and / or the holding member on the heat radiating member side, a deformed portion that is deformed by a force toward the heat radiating member is formed, and the holding frame and / or the holding member are It is preferable that the deforming portion abuts on the heat radiating member while being urged.
Here, as the deformable portion, a leaf spring portion or the like integrally formed with the holding frame or the holding member can be adopted, and the number of parts does not increase by being integrally formed in this way.
According to the present invention, the deformable portion ensures the heat conductive connection between the heat radiating member and the light modulation device or the optical conversion element, as in the case of the connection member, and the cooling is mainly performed on the light modulation device or the optical conversion element. Efficiency can be further improved.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
[1. (Schematic configuration of projector)
FIG. 1 is a plan view of the interior of the projector 1 according to the present embodiment as viewed from above.
The projector 1 is provided with an outer case 2 made of a resin having a substantially rectangular parallelepiped shape as a whole, and FIG. 1 shows a state in which the upper case (upper case) of the outer case 2 is removed and the control board and the like are further removed. Yes.
In the exterior case 2, an optical unit 4 that is an optical engine of the projector 1 is arranged in an L shape in plan view from the light source device 411 to the projection lens 46.
In this optical unit 4, the optical components 41 to 44 are accommodated in an optical component casing 47, and as shown in FIG. 1, the optical components 41 to 43 are optical component casings. 47 is held in a groove 471 inside.

Here, the projector 1 according to the present invention is characterized in that the three sirocco fans 31R, 31G, and 31B, the duct 500, and the heat radiating plate 55 constitute a cooling mechanism for cooling the optical device 44.
Here, one end of the duct 500 branches into three duct portions 51R, 51G, and 51B, and these duct portions 51R, 51G, and 51B are connected to the sirocco fans 31R, 31G, and 31B, respectively. The air sucked from the outside by 31R, 31G, and 31B is introduced into the optical device 44 through the duct portions 51R, 51G, and 51B, whereby the optical device 44 is cooled.

The sirocco fans 31R, 31G, and 31B are erected on the lower case 21 so that the rotation axis of a rotor blade (not shown) is orthogonal to the optical axis of the projection lens 46, and the sirocco fans 31R and 31G are arranged on the side surfaces of the lower case 21. The sirocco fan 31B takes in air from the inlet 212 (FIG. 1) formed in the bottom surface 21A of the lower case 21.
The upper case 22 (FIG. 4) of the outer case 2 is formed with an exhaust port (not shown) for discharging the air inside the projector 1.

  The sirocco fans 31R, 31G, and 31B and the duct portions 51R, 51G, and 51B are aligned with the projection lens 46 and are well placed in the outer case 2. The duct portions 51R, 51G, and 51B extend along the lens barrel 461 of the projection lens 46, and the ends of the duct portions 51R, 51G, and 51B are coupled to each other below the optical device 44. The optical device 44 is placed on the coupling portion of the duct portions 51R, 51G, and 51B so as to face the end portion of the lens barrel 461.

  In addition to the above, the projector 1 includes a control board (not shown), a drive circuit / cooling device for the light source device 411, a power supply unit necessary for driving the optical unit 4 and the sirocco fans 31R, 31G, 31B, etc. However, the explanation and illustration are both omitted.

[2. Configuration of optical unit)
The optical system of the optical unit 4 will be described with reference to the schematic diagram of FIG.
The optical unit 4 includes an integrator illumination optical system 41, a color separation optical system 42, a relay optical system 43, an optical device 44, and a projection lens 46.
The integrator illumination optical system 41 substantially uniformly forms the image forming areas of the three light modulation devices 440 (respectively indicated as light modulation devices 440R, 440G, and 440B for red, green, and blue color lights) constituting the optical device 44, respectively. This is an optical system for illuminating, and includes a light source device 411, a first lens array 412, a second lens array 413, a polarization conversion optical element 414, and a superimposing lens 415.

The light source device 411 includes a light source lamp 416 that is a light source that emits a radial light beam, an elliptical reflector 417 that reflects radiation emitted from the light source lamp 416, and a light source lamp 416 that is emitted from the light source lamp 416 and reflected by the elliptical reflector 417. And a collimating concave lens 411A that converts light into parallel light.
As the light source lamp 416, an ultrahigh pressure mercury lamp is used in the present embodiment. A UV filter (not shown) is provided on the plane portion of the collimating concave lens 411A.
A parabolic mirror may be used instead of the elliptical reflector 417 and the collimating concave lens 411A.

  The first lens array 412 has a configuration in which small lenses having a substantially rectangular outline when viewed from the optical axis direction are arranged in a matrix. Each small lens splits the light beam emitted from the light source lamp 416 into a plurality of partial light beams. The contour shape of each small lens is set so as to be almost similar to the shape of the image forming area of the light modulation device 440.

  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 has a function of forming an image of each small lens of the first lens array 412 on the light modulation device 440 together with the superimposing lens 415.

  The polarization conversion optical 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 optical element 414 converts the light from the second lens array 413 into a single type of polarized light, thereby improving the light use efficiency in the optical device 44.

Specifically, each partial light converted into one type of polarized light by the polarization conversion optical element 414 is finally superimposed on the light modulation devices 440R, 440G, and 440B of the optical device 44 by the superimposing lens 415. In a projector using a liquid crystal panel of a type that modulates polarized light, only one type of polarized light can be used. Therefore, almost half of the light from the light source lamp 416 that emits randomly polarized light cannot be used.
Therefore, by using the polarization conversion optical element 414, the light emitted from the light source lamp 416 is converted into almost one type of polarized light, and the use efficiency of light in the optical device 44 is enhanced. Such a polarization conversion optical element 414 is introduced in, for example, Japanese Patent Application Laid-Open No. 8-304739.

  The color separation optical system 42 includes two dichroic mirrors 421 and 422 and a reflection mirror 423, and a plurality of partial light beams emitted from the integrator illumination optical system 41 by the dichroic mirrors 421 and 422 are red, green, and blue. It has a function of separating into three color lights.

  The relay optical system 43 includes an incident side lens 431, a relay lens 433, and reflection mirrors 432 and 434, and has a function of guiding the color light and red light separated by the color separation optical system 42 to the light modulation device 440R. .

  At this time, the dichroic mirror 421 of the color separation optical system 42 reflects the blue light component of the light beam emitted from the integrator illumination optical system 41 and transmits the red light component and the green light component. 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 light modulation device 440B. The field lens 418 converts each partial light beam emitted from the second lens array 413 into a light beam parallel to the central axis (principal ray). The same applies to the field lens 418 provided on the light incident side of the other light modulation devices 440G and 440R.

Of the red light and green light transmitted through the dichroic mirror 421, the green light is reflected by the dichroic mirror 422 and passes through the field lens 418 to reach the green light modulation device 440G. On the other hand, the red light passes through the dichroic mirror 422, passes through the relay optical system 43, and further passes through the field lens 418 to reach the light modulation device 440R for red light. The relay optical system 43 is used for red light because the optical path length of the red light is longer than the optical path lengths of the other color lights, thereby preventing a decrease in light use efficiency due to light divergence or the like. Because. That is, the partial light beam incident on the incident side lens 431 is passed on to the field lens 418 as it is.
The relay optical system 43 is configured to pass red light out of the three color lights, but is not limited thereto, and may be configured to pass blue light, for example.

  The optical device 44 includes three incident-side polarizing plates 442 to which the respective color lights separated by the color separation optical system 42 are incident, and light modulation devices 440R, 440G, and 440B disposed at the subsequent stage of the respective incident-side polarizing plates 442. , An emission-side polarizing plate 443 disposed downstream of each of the light modulation devices 440R, 440G, and 440B, and a cross dichroic prism 444 as a color synthesis optical device. These optical components 440, 443, 444 are integrally formed to constitute the optical device main body 45.

The incident-side polarizing plate 442 is an optical conversion element configured separately from the optical device main body 45, and transmits only polarized light in a certain direction among the light beams separated by the color separation optical system 42. It absorbs the luminous flux in the direction.
The incident-side polarizing plate 442 includes a polarizing film in which a polyvinyl alcohol (PVA) film and an acetate cellulose-based rectangular film are laminated, and a sapphire glass substrate on which the polarizing film is attached.

[3. Configuration of optical device main body]
FIG. 3 shows the optical device main body 45.
The optical device main body 45 includes a cross dichroic prism 444, a pedestal 445 fixed to an upper end surface orthogonal to a plurality of light incident end surfaces of the cross dichroic prism 444, and three holders 480 as holding members attached to the pedestal 445. And light modulation devices 440R, 440G, and 440B attached to these holders 480.

  The cross dichroic prism 444 combines the images emitted from the light modulation devices 440R, 440G, and 440B and modulates each color light to form a color image, and is a hexahedron having a substantially cubic appearance. In the cross dichroic prism 444, a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in an approximately X shape along the interfaces of four right-angle prisms. Three color lights are synthesized by the multilayer film. The color image synthesized by the cross dichroic prism 444 is emitted from the projection lens 46 (FIG. 2) and enlarged and projected on the screen.

  The pedestal 445 is a member made of an alloy such as aluminum or magnesium having a heat conductivity, to which the holder 480 is joined, while holding the cross dichroic prism 444. The base 445 is formed according to the shape of the upper end face of the cross dichroic prism 444, and arm portions 445A extending outward are formed at the four corners. With this arm portion 445A, the optical device main body 45 is screwed to the inner surface of the optical component casing 47.

  The light modulation devices 440R, 440G, and 440B include liquid crystal panels 441R, 441G, and 441B as light modulation elements, and a panel holding frame 490 that holds the liquid crystal panels 441R, 441G, and 441B and enables heat conduction. The whole is formed in a substantially rectangular plate shape.

Although not specifically shown, the liquid crystal panels 441R, 441G, and 441B include a glass driving substrate and a counter substrate, and a TN (twisted nematic) type liquid crystal injected between these substrates, and the incident side. A light beam incident through the polarizing plate 442 is modulated according to image information and emitted.
Inside the driving substrate, there are provided pixel electrodes made of a transparent conductor such as ITO (Indium Tin Oxide), switching elements such as TFT elements corresponding to each pixel electrode, wiring, alignment films for arranging liquid crystal molecules, and the like. Yes. Further, on the inner surface of the counter substrate, a counter electrode corresponding to the pixel electrode, an alignment film whose direction is substantially orthogonal to the alignment film of the driving substrate, and the like are provided. Thereby, an active matrix type liquid crystal panel is formed.
Further, a control cable 447 extends from between the drive substrate and the counter substrate.

The panel holding frame 490 has a rectangular opening 491 corresponding to the image forming area of the liquid crystal panels 441R, 441G, 441B, and has a rectangular container shape that holds the liquid crystal panels 441R, 441G, 441B in a thermally conductive state. The frame member is made of a material having good thermal conductivity, such as magnesium, aluminum, titanium, or an alloy containing these.
A hole 492 is formed in the peripheral portion of the panel holding frame 490, and fins 493 are formed on the upper surface in consideration of heat dissipation.

The holder 480 is fixed to the pedestal 445 along the light beam incident end face of the cross dichroic prism 444, and the lower end protrudes from the lower end of the cross dichroic prism 444.
The holder 480 is constituted by two channel-shaped members having a substantially C-shaped cross section of the outer holder 481 and the inner holder 485. The outer holder 481 and the inner holder 485 are made of a material having good thermal conductivity such as aluminum, magnesium, titanium, or an alloy thereof, and are bonded and fixed face-to-face and nested, and are used as an output side polarization as an optical conversion element. The plate 443 is held in a state where it can conduct heat with the exit-side polarizing plate 443. With the structure of the outer holder 481 and the inner holder 485 as described above, the heat capacity and heat conduction efficiency of the entire holder 480 are improved.

The outer holder 481 includes a rectangular flat plate-shaped base portion 482 and a pair of upright pieces 483 that stand up from the left and right ends of the base portion 482 in the out-of-plane direction (optical axis direction).
The base 482 has a rectangular opening for light beam transmission formed substantially at the center, and the base 482 has an upper end bonded and fixed to the pedestal 445 along the light beam incident end face of the cross dichroic prism 444.

On the other hand, the inner holder 485 includes a base portion 486 having an opening and a pair of upright pieces 487, and the front end side of the upright pieces 487 is a bent piece 488 bent in a direction approaching each other. The standing pieces 487 and 483 are arranged inside the holder 481 so as to overlap each other.
The base portion 486 has four female screw holes (not shown) at the four corners, and metal screws are inserted into the female screw holes through the holes 492 of the panel holding frame 490, whereby the panel holding frame. 490 is interchangeably fixed to the inner holder 485.

  In the present embodiment, the exit-side polarizing plate 443 includes a first polarizing plate (pre-polarizer) 443P and a second polarizing plate (analyzer) 443A that have substantially the same configuration as the incident-side polarizing plate 442. The incident side polarizing plate 442 and the polarization axis are arranged so as to be orthogonal to each other. This is because the emission-side polarizing plate 443 has a relationship of realizing the gradation characteristics of the color of the optical image by changing the transmittance of the emission-side polarizing plate 443 according to the applied voltage of the liquid crystal panels 441R, 441G, 441B. Since the temperature easily rises due to the heat of absorption of light, the polarized light flux incident through the incident side polarizing plate 442 is divided and absorbed by the first polarizing plate 443P and the second polarizing plate 443A, thereby absorbing light. This is because the heat is apportioned by both polarizing plates 443P and 443A to suppress overheating.

A silicone-based heat conductive adhesive is used to attach the first polarizing plate 443P and the second polarizing plate 443A to the holder 480, and the first polarizing plate 443P is the back side of the bent piece 488 of the inner holder 485. The second polarizing plate 443A is adhered around the opening of the outer holder 481. However, the present invention is not limited to this, and it is adhered to the front surface side of the bent piece 488, the periphery of the opening portions of the outer holder 481 and the inner holder 485 (front surface side / rear surface side), or the first polarizing plate 443P and the second polarized light. A protrusion for holding the plate 443A or the like may be formed. These polarizing plates 443P and 443A can be exchanged together with the holders 481 and 485.
In addition to the polarizing plates 443A and 443B, optical conversion elements such as a viewing angle correction plate and a retardation plate can be attached to the outer holder 481 and the inner holder 485.

[4. (Configuration of duct and heat sink)
Next, a configuration for cooling the optical device 44 will be described focusing on the duct 500 and the heat radiating plate 55.
FIG. 4 shows the optical device main body 45, the sirocco fans 31R, 31G, and 31B, the duct 500, the heat radiating plate 55, and the like arranged in the outer case 2 with the outer case 2 cut away. In FIG. 4, the optical component casing 47 (FIG. 1), the incident side polarizing plate 442 (FIG. 2), and the like are not shown. FIG. 5 is a partial perspective view of the duct 500.
In the present embodiment, the cooling air sucked from the sirocco fans 31R, 31G, and 31B is led to the optical device 44 through the duct 500 branched into the duct portions 51R, 51G, and 51B, and is cooled. The heat dissipation plate 55 is provided in the duct 500.

Here, with respect to the branching shape of the duct 500, the duct portions 51R, 51G, and 51B correspond to the optical paths of the respective color lights incident on the liquid crystal panels 441R, 441G, and 441B, respectively, and these three duct portions 51R, 51G, 51B extends from a position where the sirocco fans 31R, 31G, 31B are provided to a position facing each of the light modulation devices 440R, 440G, 440B, and as shown in FIGS. 4 and 5, a cross dichroic prism 444 (FIG. 3). The shape is aligned with the branching portion 501 in the vicinity of the lower end surface orthogonal to the plurality of light beam incident end surfaces.
This duct 500 is a two-body synthetic resin injection molded product divided along the extending direction (air flow direction) of the duct portions 51R, 51G, 51B. FIG. Of these, a channel-shaped upper duct 500A in which a heat radiating plate 55 is disposed is shown. The lower duct (not shown) constituting the lower half of the duct portions 51R, 51G, 51B has substantially the same shape as the upper duct 500A, and the lower duct and the upper duct 500A are formed in the vicinity of the mating surfaces of each other. The fixed portion 500A1 is screwed.

  Each of the duct portions 51R, 51G, and 51B is a substantially cylindrical body having a rectangular cross section. In these duct portions 51R, 51G, 51B, introduction portions 511R, 511G, 511B, which are one opening portion, are respectively arranged opposite to the outlets of the sirocco fans 31R, 31G, 31B, and from these introduction portions 511R, 511G, 511B, respectively. The lower half of the lower duct (not shown) extends along the bottom surface 21A (FIG. 1) of the lower case 21 and extends to the lead-out portions 512R, 512G, and 512B that are the other openings facing the optical device 44. The upper half constituting the duct 500A has a shape that gradually decreases in diameter. Further, the side surfaces of the duct portions 51R, 51G, and 51B are combined at the branch portion 501, and the surface of the branch portion 501 is planar.

  When this bifurcated portion 501 is viewed in plan, as shown in FIG. 5, the end portions of the duct portion 51R and the duct portion 51B face each other, and the end portion of the duct portion 51G is positioned with the end portion of the duct portion 51R. Are arranged in an L-shape when the end portions of these duct portions 51R, 51G, 51B are traced. This L-shaped portion is a notch 502 in the upper duct 500A. The notch 502 is opened laterally at the periphery from the duct portion 51R side to the duct portion 51B side, and the periphery of the heat sink 55 Is formed.

FIG. 6 is an exploded perspective view of the upper duct 500 </ b> A with the heat dissipation plate 55 removed from the groove 503. Inside the branch portion 501, partitions 504R, 504G, and 504B extending orthogonally to the air flow guided by the duct portions 51R, 51G, and 51B are disposed around the ribs 505 that are lattice-like in plan view. .
The rib 505 reinforces the branch portion 501, and a female screw hole 505 </ b> A into which the heat radiating plate 55 is screwed is formed at the center of the lattice. Therefore, the upper duct 500A can be easily assembled by inserting the heat sink 55 into the groove 503 and screwing it into the female screw hole 505A.
Due to the presence of these partitions 504R, 504G, 504B, the air inside the duct portions 51R, 51G, 51B does not mix with each other, and the light modulation devices 440R, 440G, 440B, etc. are provided for each of the duct portions 51R, 51G, 51B. Each can be reliably cooled.

Ribs or the like can be appropriately formed in the branch portion 501 in order to adjust the wind pressure and the direction of the air blown from the lead-out portions 512R, 512G, and 512B (FIG. 5).
Here, by forming a pair of rectifying plates 506 along the air flow at a position corresponding to the lead-out part 512R, the opening of the lead-out part 512R is narrowed, and the derived wind speed is increased. .
Note that the lower duct (not shown) constituting the lower half of the duct portions 51R, 51G, and 51B is also formed with partitions, ribs, and rectifying plates in the same manner as the upper duct 500A.

As shown in FIGS. 5 and 6, the heat dissipation plate 55 is disposed in the branch portion 501 so as to cover the notch 502, and aluminum, magnesium, titanium, iron, copper, an alloy thereof, a heat conductive resin, or the like, Here, it is press-molded as an L-shaped plate having a thickness of 1 mm with a material having good thermal conductivity.
The heat radiating plate 55 is formed with three holes 551R, 551G, and 551B that communicate with the inside of the duct portions 51R, 51G, and 51B and constitute the lead-out portions 512R, 512G, and 512B (FIG. 4). The air guided to the ducts 51R, 51G, 51B changes its direction at the position of the optical device 44, and substantially follows the image forming area surface of the liquid crystal panels 441R, 441G, 441B from these holes 551R, 551G, 551B. Derived in each direction. As a result, air is supplied to the entire surface of the image forming area of the liquid crystal panels 441R, 441G, and 441B, so that color unevenness of the projected image does not occur.

Here, the shapes and positions of the holes 551R, 551G, and 551B of the heat radiating plate 55 take into consideration the shapes and temperatures of the light modulators 440R, 440G, and 440B (FIG. 4) and the emission-side polarizing plate 443 (FIG. 3). Thus, it is appropriately determined so as to obtain a desired wind direction, wind pressure, and air volume. As a result, the temperatures of the light modulation devices 440R, 440G, and 440B can be averaged.
For example, the hole 551G is formed to have a smaller size in the direction of airflow than the other holes 551R and 551B, and increases the wind pressure and the wind speed to focus on the light modulation device 440G. ing. Further, the hole 551G is formed at a position shifted from the position facing the light modulation device 440G to the windward side of the air flow in the duct portion 51G. This is because the air in the duct portion 51G flows in the lateral direction along the extending direction of the duct portion 51G. This is because wind noise at 551G is also reduced, and air is easily supplied to the entire light modulation device 440G.
On the other hand, the hole 551B is formed larger than the other holes 551R and 551G, and uniformly blows air in the vicinity of the light modulation device 440B, that is, the light modulation device 440B, the incident side polarizing plate 442, the emission side polarizing plate 443, and the like. It has become.

  Further, the shape of the heat dissipation plate 55 itself including the shapes of the holes 551R, 551G, and 551B of the heat dissipation plate 55, and the position, size, material, and the like of the heat dissipation plate 55 are appropriately determined in consideration of the heat dissipation performance. . Here, the heat radiating plate 55 is provided along the side surface of the duct 500 so as to cover the notch 502, and the area of the heat radiating plate 55 can be easily expanded along the side surface of the duct 500. For example, the heat dissipation performance of the heat dissipation plate 55 can be improved by extending outside the notch 502 to increase the area of the heat dissipation plate 55.

As shown in FIG. 4, the optical device main body 45 is placed on the branch portion 501 of the duct 500 described above. Therefore, taking advantage of the layout of the duct 500 arranged on the bottom surface 21 </ b> A of the lower case 21, the optical device body 45 is supported by the duct 500, and other members that support the optical device body 45 on the lower case 21 are used. Can be unnecessary.
Specifically, the optical device main body 45 is placed at substantially the center of the heat radiating plate 55 surrounded by the holes 551R, 551G, and 551B, and the heat radiating plate 55 is supported by the ribs 505 (FIG. 6) inside the branch portion 501. Has been. In FIG. 4, the optical component casing 47 is not shown, but the optical device main body 45 is actually placed on the duct 500 via the optical component casing 47 (FIG. 1). . In the optical component casing 47, openings (not shown) are formed at positions corresponding to the holes 551R, 551G, and 551B of the heat radiating plate 55, and the air in the duct portions 51R, 51G, and 51B is radiated from the heat radiating plate. 55 and the optical device casing 47 are supplied to the optical device main body 45 through the optical component casing 47. Further, an opening corresponding to the exhaust port (not shown) of the upper case 22 of the outer case 2 is formed in the optical component casing 47, and the air inside the optical component casing 47 is discharged through this opening. The

  The optical device main body 45 and the heat radiating plate 55 are connected to each other on the three side surfaces of the cross dichroic prism 444 via a tape TP as a connecting member made of a heat conductive resin material so as to be able to conduct heat. This tape TP has flexibility, one end is bonded to the lower end of the upright piece 483 (FIG. 3) of the outer holder 481, bent in an L shape, and the other end is a heat sink. It is adhered to the surface of 55. In addition, this tape TP may connect not only between the holder 480 and the heat sink 55 but between the panel holding frame 490 and the heat sink 55 so that heat conduction is possible.

Next, the operation of cooling the optical device 44 by the sirocco fans 31R, 31G, 31B, the duct 500, and the heat radiating plate 55 will be described with reference to FIGS.
The incident-side polarizing plate 442, the light modulation devices 440R, 440G, and 440G, the first polarizing plate 443P, the second polarizing plate 443A, and the like (see FIGS. 2 and 3) of the optical device 44 increase in temperature when irradiated with incident light. To do. In particular, the first polarizing plate 443P and the second polarizing plate 443A become very hot due to the absorption of light, but the heat is first conducted to the holder 480, and from the holder 480 via the tape TP (FIG. 4). Conducted to the heat sink 55. Thereby, the heat generated in the first polarizing plate 443P and the second polarizing plate 443A is dispersed in the heat radiating plate 55, and the entire temperature is made uniform and the temperature is lowered. The heat of the holder 480 is also conducted to the optical component casing 47 (FIG. 1) via the base 445. The heat conducted to the heat radiating plate 55 and the optical component casing 47 is finally released to the outside through the exterior case 2.
In addition, the heat of the liquid crystal panels 441R, 441G, and 441B is first conducted to the panel holding frame 490, then to the holder 480 through the screw inserted in the hole 492, and further generated in the exit side polarizing plate 443. Like heat, it is conducted from the holder 480 to the heat radiating plate 55 and released to the outside.

On the other hand, air introduced from the sirocco fans 31R, 31G, and 31B to the ducts 51R, 51G, and 51B via the introduction portions 511R, 511G, and 511B is supplied from the lead-out portions 512R, 512G, and 512B to the liquid crystal panels 441R, 441G, The light is blown in a direction substantially along the surface of the image forming area 441B and supplied to the incident-side polarizing plate 442, the light modulation devices 440R, 440G, and 440B, the emission-side polarizing plate 443, and the like. Thus, the incident-side polarizing plate 442, the light modulation devices 440R, 440G, and 440B, the emission-side polarizing plate 443 and the like are cooled by heat absorption by the air, and the air warmed by the heat absorption is an optical component. It is discharged through the opening of the housing 47 and the opening (both not shown) of the upper case 22 (FIG. 4) of the outer case 2.
Here, when air is led out from the lead-out portions 512R, 512G, and 512B, as can be seen from FIGS. 5 and 6, this air flow passes through the holes 551R, 551G, and 551B of the heat radiating plate 55 and the holes 551R. , 551G and 551B, the heat radiating plate 55 is exposed to this air flow. That is, the heat radiating plate 55 serving as the heat sink of the optical device 44 is directly cooled by the external air. As described above, the cooling of the optical device 44 is efficiently performed by the synergistic action of the air cooling and the heat radiation cooling, so that the life of the liquid crystal panels 441R, 441G, 441B, the emission side polarizing plate 443, and the like is extended. Can be connected.
On the other hand, since the duct portions 51R, 51G, and 51B, which are indispensable components for blowing air to the optical device 44, have the heat radiation plate 55, the space beyond the duct portions 51R, 51G, and 51B becomes unnecessary, and thus downsizing is impeded. It is never done.

Here, in the present embodiment, a test example in which the following conditions are set is shown below.
(Condition 1)
The heat radiating plate 55 was connected to the holder 480 by the tape TP (similar to the configuration described above).
(Condition 2)
Do not use tape TP.

[Test example]
The projector 1 was operated, and the temperatures of the first polarizing plate 443P and the second polarizing plate 443A facing the liquid crystal panel 441G were measured for each of the above conditions 1 and 2. Note that air blowing to the optical device 44 by the duct 500 is performed in both cases of Conditions 1 and 2.
〔result〕

  As shown in Table 1, in both the first polarizing plate 443P and the second polarizing plate 443A, the temperature is lower in the condition 2 than in the condition 1, and the temperature difference is around 2 ° C. From this test result, it was confirmed that the cooling performance of the optical device 44 is improved by adding heat dissipation of the heat dissipation plate 55 to the air blown by the duct 500.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
In the following description, the same reference numerals are given to the same configurations as those in the embodiment described above, and the description is omitted or simplified.
In 1st Embodiment, the heat sink 55 was connected to the holder 480 so that heat conduction was possible by using tape TP (FIG. 4).
On the other hand, the second embodiment is different in that the holder 480 has a deformed portion instead of using the tape TP. This will be specifically described below.

FIG. 7 shows the optical device main body 75 and the like of the present embodiment disposed in the exterior case 2. In FIG. 7, the optical component casing 47 (FIG. 1), the incident side polarizing plate 442 (FIG. 2), and the like are not shown.
FIG. 8 shows the optical device main body 75. The optical device main body 75 is different from the optical device main body 45 of the above-described embodiment in the shape of the outer holder 781. That is, the lower end portion of the upright piece 783 of the outer holder 781 is a leaf spring portion 783A having a substantially square cross section extending to the heat radiating plate 55 as a deformed portion. Further, a grounding portion 783B extending from the lower end of the heat sink 55 substantially in parallel with the surface of the heat radiating plate 55 (FIG. 7) is formed. When the optical device main body 75 is placed in the same duct 500 as in the above-described embodiment, the grounding portion 783 </ b> B protrudes from the opening of the optical component casing 47 (not shown) and comes into contact with the heat radiating plate 55. Here, the leaf spring portion 783A is compressed by the dead weight of the optical device main body 75, and the grounding portion 783B comes into contact with the heat radiating plate 55 in an urged state, so that the heat radiating plate 55 is interposed via the leaf spring portion 783A. Is securely connected to the optical device main body 75 so as to be able to conduct heat. Here, since the leaf spring portion 783A is integrally formed with the outer holder 781, heat conduction between the heat radiating plate 55 and the optical device main body 75 can be achieved without increasing the number of components.

  In this embodiment, the cooling action and effect of the optical device 44 (FIG. 2) by the sirocco fans 31R, 31G, 31B, the duct 500 and the heat radiating plate 55 are substantially the same as those in the above embodiment. That is, the optical device 44 is sufficiently and efficiently cooled by the two systems of air cooling through the duct 500 and heat radiation cooling by the heat radiation plate 55 through the leaf spring portion 783A of the holder 480, and the duct 500 is cooled. The provision of the heat dissipation plate 55 does not hinder downsizing.

The present invention is not limited to the above-described embodiments, and includes the following improvements and modifications.
The shape, position, number, and the like of the duct and the heat sink are not limited to the above embodiments.
In the present invention, the minimum configuration for cooling the optical device is a fan, one duct, and a heat sink. As described above, the configuration of the present invention can also be applied to a single-plate optical device in which one light modulation device is used by the configuration including one duct. However, the number of light modulation devices may not correspond to the number of ducts, and a configuration including one duct allows a three-plate optical device including three light modulation devices as in the above-described embodiment, It can be set as the structure which cools an optical apparatus provided with a light modulation apparatus or four or more light modulation apparatuses. Moreover, the structure which guides with respect to one light modulation apparatus from several ducts may be sufficient.
In each of the above embodiments, the duct 500 is branched into the duct portions 51R, 51G, and 51B. However, the duct portions 51R, 51G, and 51B may be independent ducts.

And the fan which one opening part of a duct opposes was provided with one sirocco fan 31R, 31G, 31B for each duct part 51R, 51G, 51B in the said embodiment, However, It is not restricted to this, For example, it is good also as a structure which ventilates several ducts from one fan. Conversely, air may be blown from two or more fans to one duct. It is preferable to use a plurality of fans in terms of suppressing the bulkiness of the fans in the radial direction.
The type of fan is not limited to a sirocco fan, and an axial fan or the like can also be employed.

  In the present invention, when the optical device includes an optical conversion element such as a polarizing plate, a viewing angle correction plate, a retardation plate, a color filter, etc. in addition to the light modulation device, these optical conversion elements are also to be cooled. To do. Therefore, what is necessary is just to set it as the structure which aims at the forced cooling by introduction of external air, and the thermal radiation by a heat sink suitably according to the form of these cooling object.

In the embodiment, the optical device main body 45 is placed on the duct 500, but the configuration is not limited thereto. For example, in the above-described embodiment, the duct 500 may be disposed above the optical device 44, and the air flow may be blown down to the optical device 44 through the lead-out portions 512R, 512G, and 512B.
In addition, the duct and the optical device are not arranged so as to overlap each other in this manner, but the duct and the optical device are arranged side by side, and air is introduced from the side along the image forming region surface of the light modulation device. You can also

The type of the light modulation element is not limited to the above embodiment, and a micro device mirror or the like can be adopted as the light modulation element.
Further, in addition to the transmission type light modulation element using a transparent electrode as in the above-described embodiment, a reflection type light modulation element using a reflection electrode can also be employed.

  The present invention is also applicable to a rear type projector that projects from the rear side of the screen viewing direction, in addition to the front type projector 1 that projects from the screen viewing direction as in the above embodiments. it can.

  The present invention can be widely used as various projectors for presentation use and home theater use that require high brightness and downsizing due to its excellent cooling performance.

FIG. 2 is a plan view illustrating a schematic configuration of the projector according to the first embodiment. The schematic diagram of the optical unit in the said embodiment. The perspective view of the optical apparatus main body in the said embodiment. The perspective view of the optical apparatus main body in the said embodiment, a fan, a duct, and a heat sink. The partial perspective view of the duct and the heat sink in the said embodiment. FIG. 6 is an exploded perspective view of FIG. 5. The perspective view of the optical apparatus main body, a fan, a duct, and a heat sink in 2nd Embodiment. The perspective view of the optical apparatus main body in the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Projector, 31R, 31G, 31B ... Sirocco fan (fan), 44 ... Optical apparatus, 45, 75 ... Optical apparatus main body, 51R, 51G, 51B ... Duct part, 55 ... Radiating plate (heat radiating member), 440R, 440G , 440B: Light modulation device, 441R, 441G, 441B ... Liquid crystal panel (light modulation element), 442 ... Incident side polarizing plate (optical conversion element), 443 ... Emission side polarizing plate (optical conversion element), 444 ... Cross dichroic prism (Color synthesizing optical device) 480 ... Holder (holding member), 481, 781 ... Outer holder, 485 ... Inner holder, 490 ... Panel holding frame (holding frame), 500 ... Duct, 501 ... Branch, 511R, 511G, 511B ... Introducing section (one opening), 512R, 512G, 512B ... Deriving section (other opening), 551R, 551G, 51B ... hole, 783A ... plate spring portion (deformed portion), TP ... tape (connecting member).

Claims (9)

A projector comprising an optical device having a light modulation device that modulates a light beam emitted from a light source according to image information to form an optical image, and a fan for introducing cooling air from the outside,
One opening is disposed opposite to the fan, the other opening faces the light modulation device, and a duct that guides cooling air introduced from the fan to the light modulation device,
It is provided in the vicinity of the other opening of the duct and according to the arrangement of the light modulation device, and includes a heat radiating member made of a heat conductive material connected to the optical device so as to be capable of heat conduction. projector. The projector according to claim 1, wherein
The projector, wherein the heat radiating plate extends along a side surface of the duct. In the projector according to claim 1 or 2,
A color separation optical system for separating a light beam emitted from the light source into a plurality of color lights;
The optical device includes a plurality of light modulation devices that form an optical image by modulating each color light separated by the color separation optical system, and a plurality of light beam incident end faces that face the light modulation devices, A color synthesizing optical device for synthesizing an optical image formed by the light modulation device,
The projector is characterized in that the duct branches inside according to the plurality of light modulation devices, and the other opening faces each of the light modulation devices. The projector according to claim 3, wherein
The projector is characterized in that the duct extends in the vicinity of one end surface intersecting with a plurality of light beam incident end surfaces of the color combining optical device. The projector according to any one of claims 1 to 4,
The projector is characterized in that a hole is formed in the heat radiating member at a position corresponding to the other opening of the duct. The projector according to any one of claims 1 to 5,
The light modulation device includes a light modulation element that performs light modulation, and a heat conduction member that holds the periphery of the light modulation element in a state in which heat modulation is possible with the light modulation element and extends along the flow of the cooling air. A holding frame made of a functional material,
The projector is characterized in that the heat radiating member is connected to the holding frame so as to conduct heat. The projector according to any one of claims 1 to 6,
The optical device includes an optical conversion element that optically converts the light beam modulated by the light modulation device, a peripheral edge of the optical conversion element in a state of being thermally conductive with the optical conversion element, and the cooling air. A holding member made of a thermally conductive material extending along the flow,
The projector is characterized in that the heat radiating member is connected to the holding member so as to conduct heat. The projector according to claim 6 or 7,
The projector, wherein the holding frame and / or the holding member and the heat radiating member are connected by a connecting member having flexibility and thermal conductivity. The projector according to claim 6 or 7,
At the end of the holding frame and / or the holding member on the heat radiating member side, a deformed portion that is deformed by a force toward the heat radiating member is formed,
The projector according to claim 1, wherein the holding frame and / or the holding member abuts on the heat radiating member at the deforming portion.

Images