JP2003057754A - Cooler and projector provided with it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooler which cools optical elements with satisfactory efficiency and enables an optical device provided with the optical elements to be easily miniaturized, and to provide a projector provided with the cooler. SOLUTION: A cooler 70 provided with a heat pipe 712, a Peltier module 714, and an axial-flow fan 72 is provided for an optical device 44. Heat generated in the optical device 44 is absorbed by the Peltier module 714 through the heat pipe 712, and the Peltier module 714 is cooled by the axial-flow fan 72, and then the optical device 44 is cooled. Since the optical device 44 is cooled by migrating the heat of the optical device 44 to the Peltier module 714 through the heat pipe 712, the optical device 44 is surely cooled even when gaps between close optical elements are small, and the cooling efficiency is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device and a projector equipped with the cooling device.

[0002]

2. Description of the Related Art Conventionally, an optical device having a plurality of optical elements inside has a cooling device for cooling the optical elements because the temperature of the optical elements rises due to transmission or reflection of light. This cooling device normally performs cooling by air cooling, and includes an intake fan that sucks cooling air from the outside and an exhaust fan that discharges the cooling air that has finished cooling the optical element to the outside. Such a cooling device is generally provided with a duct for guiding the sucked cooling air to a predetermined optical element.

[0003]

However, in the cooling device as described above, cooling is performed by blowing cooling air to the optical element. Therefore, when the optical elements are close to each other and the gap between them is small, it is difficult for cooling air to enter the gap, so that there is a problem that the cooling efficiency is poor and the optical element is easily deteriorated.

In order to avoid such a problem, it is conceivable to increase the amount of cooling air passing through the optical device to improve the cooling efficiency, but this requires a larger intake fan or exhaust fan. Larger fans lead to larger optical devices, which is an obstacle to the downsizing of optical devices.
There is a problem. Further, it is possible to improve the cooling efficiency by blowing as fresh as possible the cooling air (cooling air having a low temperature) to the optical element to be cooled, but in order to blow the fresh cooling air to the optical element, It is necessary to install a fan near the optical element so that the air taken in from outside can be immediately blown to the optical element. However, a space for installing the fan has to be formed in the vicinity of the optical element, and the fan cannot be arranged by utilizing the empty space, so that the degree of freedom in design is reduced.

It is an object of the present invention to provide a cooling device which can improve the cooling efficiency of an optical element and facilitate downsizing of an optical device including the optical element, and a projector including the cooling device.

[0006]

The cooling device of the present invention is a cooling device for cooling an optical element, and in order to achieve the above object, a contact member that contacts the optical element and one end side of the contact member. And a cooling mechanism that forcibly cools the other end side of the heat conducting member.

The contact member may be either a point contact member or a surface contact member with respect to the object to be cooled. However, the larger the contact area between the object to be cooled and the contact member is, Since the amount of heat transfer to the surface becomes large, a surface contact is preferable. As the method of attaching the contact member to the cooling target, the method of attaching via an adhesive, the method of attaching them by fitting them together, the method of attaching via a fixing member such as a screw, or the direction of approaching each other with a clip etc. Various methods such as a method of attaching by force can be adopted. As the heat-conducting member, heat is transmitted through the heat-conducting member without movement of a substance, a heat-conducting member utilizing so-called heat conduction, and having a refrigerant inside to cause heat transfer with the movement of the refrigerant, so-called convection. Any of the heat conducting members utilizing heat transfer can be adopted. As a cooling mechanism,
Examples thereof include those that are provided with a coolant supply means such as a fan that blows a refrigerant to the other end side of the heat conducting member, and those that are provided with heat radiating means such as fins that are connected to the other end side of the heat conducting member to radiate heat.

According to the present invention, the heat generated in the object to be cooled (optical element) due to the transmission / reflection of light is moved to the contact member and the heat conducting member in order, and the heat is generated by the cooling mechanism on the other end side of the heat conducting member. Energy is taken away, which cools the object to be cooled. Since heat can be cooled by moving heat from the optical element to the contact member, it is possible to attach the contact member to at least one end of the optical element even if the gap between the optical elements adjacent to each other is small. Can be reliably cooled, and deterioration of the optical element can be prevented. Also, after guiding the heat generated by the optical element to a position away from the object to be cooled by the heat conducting member,
It is cooled by the cooling mechanism. Therefore, in a device equipped with an optical element (object to be cooled), the cooling mechanism is installed in an empty space, and the heat conducting member guides heat to the cooling mechanism, so that the installation space of the cooling mechanism is not created. I'm done. Therefore, the degree of freedom in designing the device is increased, and it is possible to prevent the cooling device according to the present invention from becoming an obstacle to downsizing of the device, which facilitates downsizing of the device.

In the cooling device of the present invention, as the cooling mechanism, a cooling mechanism including a Peltier module utilizing the Peltier effect, a fin connected to the other end of the heat conducting member and the cooling air are blown to the fin. Any cooling mechanism configured to include a turning fan can be employed.

When a cooling mechanism composed of a Peltier module is adopted as the cooling mechanism, the heat absorbing portion of the Peltier module is connected to the other end side of the heat conducting member. In such a case, when a direct current is applied to the Peltier module, a part that generates heat (heat generating part) and a part that absorbs heat (heat absorbing part) are generated in the Peltier module. By connecting to the other end of the member, heat can be taken from the heat conducting member. Thereby, the optical element which is the cooling target can be cooled via the heat conducting member. Especially, in the cooling mechanism consisting of Peltier module,
If a fan that blows cooling air is provided, the heat-generating portion can be cooled, so that it is possible to prevent the temperature of the heat-generating portion from rising when the Peltier module is used. Further, if fins are attached to the heat generating portion of the Peltier module, cooling efficiency can be improved.

On the other hand, when a cooling mechanism including fins and a fan is used as the cooling mechanism, the fins can radiatively cool the other end of the heat conducting member, and the fan can improve the cooling efficiency. Thereby, the optical element which is the cooling target can be cooled via the heat conducting member. The Peltier module or the fins may be arranged on the intake side of the fan or on the exhaust side of the fan, and cooling air can be blown by the fan regardless of the arrangement. Becomes

In the cooling device of the present invention, the heat conducting member is
It is preferable that the heat transfer member is formed in a tubular shape, and a refrigerant is contained in the tube, and the refrigerant circulates in the tube to perform heat transfer in the heat conducting member. In this way, if a heat-conducting member that uses the internal circulation of the refrigerant is adopted, compared to the case where a heat-conducting member that uses heat conduction is adopted,
Since heat is transferred quickly within the heat conducting member, cooling efficiency can be improved.

In the cooling device of the present invention, the contact member is
Being formed of a material having a higher thermal conductivity than the optical element In this way, if the contact member is formed of a material having a higher thermal conductivity than the optical element, the heat generated in the optical element is applied to the contact member. Since it can be quickly released, heat can be prevented from accumulating in the optical element and deterioration of the optical element can be prevented.

In the cooling device of the present invention, the optical element is
At least one of a liquid crystal panel, a polarizing plate, a polarizing beam splitter, and a light source device is desirable. Here, the light source device includes a light emitting body that emits light, and such a light source device includes, for example, a light emitting body and a reflector that reflects light from the light emitting body in substantially one direction. Also included is a light source device and the like. It is an optical element that generates a particularly high amount of heat due to the absorption of light.
Use of the cooling device according to the present invention having a high cooling efficiency for cooling the liquid crystal panel, the polarizing plate, the polarization beam splitter, and the light source device makes the present invention highly useful.

On the other hand, the projector of the present invention is characterized by being provided with any one of the above-mentioned cooling devices in order to achieve the above object. According to the present invention, it is possible to enjoy a projector that exhibits substantially the same actions and effects as the actions and effects of the cooling device described above. Further, by using the above-described cooling device, it is possible to easily reduce the size of the projector, and it is possible to reliably cool the optical element inside the projector and prolong the life of the projector.

In the projector according to the present invention, it is desirable that the cooling mechanism is arranged laterally of the projection lens. In a projection lens that projects an optical image from the rear to the front, a plurality of optical elements that guide light to the projection lens are usually arranged on the rear side of the projection lens. Since elements and the like are not arranged, a relatively vacant space is likely to occur. By arranging the cooling mechanism by utilizing such an empty space beside the projection lens, when the cooling device according to the present invention is adopted in the projector, it is possible to eliminate a large design change inside the projector.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. First Embodiment [1. Main Configuration of Projector] FIG. 1 shows a first embodiment of the present invention.
2 is an overall perspective view of the projector 1 according to the embodiment as seen from above, FIG. 2 is an overall perspective view of the projector 1 as seen from below, and FIGS. 3 to 5 are perspective views showing the inside of the projector 1. Specifically, FIG. 3 is a diagram in which the upper case 21 of the projector 1 is removed from the state of FIG. 1, and FIG.
From the state of the upper shield plate 81, driver board 9
0 and the view seen from the rear side with the upper light guide 472 removed, and FIG. 5 is a view with the optical unit 4 removed from the state of FIG. These parts 4, 2 that make up the projector
1, 81, 90 and 472 will be described in detail below.

In FIG. 1 and FIG. 2, the projector 1
Is provided with an outer case 2 having a substantially rectangular parallelepiped shape as a whole. The outer case 2 includes an upper case 21, a lower case 23, and an interface cover 22, which are made of resin. Interface cover 22
Are arranged on the back side of the projector 1.

The upper case 21 is a top surface portion 21 which constitutes the top surface, front surface, and side surface of the projector 1, respectively.
1, the front surface part 214 and the side surface part 212 are comprised. On the front side of the upper surface portion 211, a lamp cover 24 as a lid portion is provided so as to be fitted and detachable, and at a position apart from the lamp cover 24, as an operation switch for unlocking the lamp cover 24 by operation. The operation switch section 24A is provided. Further, in the upper case 21, a cutout portion 21A is formed on the side of the lamp cover 24 from the upper surface portion 211 to the front surface portion 214. From the cutout portion 21A, a part of the projection lens 46 arranged inside the outer case 2 is
It is exposed to the outside. Here, the projection lens 46 is disposed in the cutout portion 21A in a state where the upper surface portion thereof is exposed, and zoom operation and focus operation of the projection lens 46 can be manually performed via a lever. Further, in the upper surface portion 211 of the upper case 21, an operation panel 25 is provided on the rear side of the cutout portion 21A.

The lower case 23 is a bottom surface portion 23 which constitutes the bottom surface, the side surface, and the back surface of the projector 1, respectively.
1, the side surface portion 232, and the back surface portion 233 are included. A first attitude adjusting mechanism 27 that adjusts the tilt of the projector 1 in the front-rear direction to position the projected image is provided on the front side of the bottom surface portion 231. Also,
A second attitude adjusting mechanism 28 that adjusts the inclination of the projector 1 in the left-right direction that is substantially orthogonal to the front-rear direction is provided in one corner on the rear side of the bottom surface 231, and the position is adjusted in the other corner. Although not possible, a rear foot 231A corresponding to the second posture adjusting mechanism 28 is provided. Further, the bottom surface portion 231 is provided with a cooling air intake port 231B. An attachment portion 232A for rotatably attaching the U-shaped handle 29 is provided on the one side surface portion 232.

An exhaust port 2E is provided on the front side of such an outer case 2 on the side opposite to the side where the projection lens 46 (notch 21A) is provided. The exhaust port 2E is formed by notching the upper case 21 and the lower case 23, respectively.
A safety cover 26 is attached to E. The safety cover 26 is provided with a plurality of blade plates 261 so that the exhaust gas discharged from the exhaust port 2E flows from the right side in FIG. 1 to the left direction (the direction away from the projection lens 46) by these blade plates 261. It has become. One side surface side of the outer case 2 (side surface side near which the projection lens 46 is arranged)
The exhaust port 2 at a position corresponding to the side of the projection lens 46 across the upper case 21 and the lower case 23.
F is provided. The exhaust port 2F is formed by notching the side surface portion 212 of the upper case 21 and the side surface portion 232 of the lower case 23, and the safety cover 60 is attached to the exhaust port 2F. The safety cover 60 is provided with a plurality of vane plates 61, and these vane plates 61 allow exhaust air discharged from the exhaust port 2F to flow from the back side to the front side in FIG. As a result, exhaust gas can be prevented from hitting a person on the side of the projector 1.

The other side of the outer case 2 (handle 2
9 is not provided on the side), the upper case 2
Each of the side surfaces 212 and 232 of the lower case 1 and the lower case 23 is provided with a side foot 2A (FIG. 2) that serves as a foot when the projector 1 is set up with the handle 29 facing upward. In addition, on the back side of the outer case 2, the back surface 233 of the interface cover 22 and the lower case 23 is provided.
An interface portion 2B formed of a recess extending over the interface portion 2B is provided, and an interface board (not shown) on which various connectors are mounted is arranged inside the interface portion 2B. A speaker hole 2C and an intake port 2D are provided on both left and right sides of the interface section 2B so as to straddle the interface cover 22 and the rear section 233 of the lower case 23.

On the other hand, inside the outer case 2, as shown in FIG. 4, a power supply unit 3 arranged on the right side in the figure and an optical unit 4 having a substantially U-shaped plane arranged from the substantially center to the left side in the figure. Is housed. The power supply unit 3 is
It is composed of a power supply 31 and a lamp drive circuit (ballast) 32 arranged on the side of the power supply 31. The power supply 31 is
The power supplied through the power cable is supplied to the lamp drive circuit 32, the driver board 90 (FIG. 3) and the like, and is provided with an inlet connector 33 (FIG. 2) into which the power cable is inserted. Lamp drive circuit 32
Supplies electric power to the light source lamp 411 of the optical unit 4, and is arranged near the light source device 413 of the optical unit 4 and electrically connected to the light source lamp 411.
Such a lamp drive circuit 32 is wired, for example, on a substrate (not shown). The power supply 31 and the lamp drive circuit 32 are arranged substantially parallel to each other, and their occupied space extends from the front of the projector 1 to the rear. Further, the power supply 31 and the lamp drive circuit 32 are
They are covered with a power supply shield plate 82 and a lamp drive circuit shield plate 83, each of which is a metal plate.
This prevents leakage of electromagnetic noise from the power supply 31 and the lamp drive circuit 32 to the outside.

As shown in FIGS. 4, 6 and 7, the optical unit 4 is a unit for optically processing the light flux emitted from the light source lamp 411 to form an optical image corresponding to image information. , 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 as a projection optical system.

The power supply unit 3 and the optical unit 4 are composed of an upper shield plate 81 (FIG. 3) arranged above the units 3 and 4, and a lower shield plate 84 arranged below the units 3 and 4 (FIG. 5). ) Is covered by. This prevents leakage of electromagnetic noise from the power supply unit 3 and the driver board 90 to the outside.

[2. Detailed Configuration of Optical System] In FIGS. 4 and 7, the integrator illumination optical system 41 is the optical device 4
4 liquid crystal panels 441 (liquid crystal panels 441R, 441G, 441 respectively for red, green, and blue color lights)
(Shown as B) is an optical system for illuminating the image forming area of the first lens array 4 and the light source device 413.
18, the second lens array 414, and the polarization conversion element 41.
5, the first condenser lens 416, and the reflection mirror 42
4 and a second condenser lens 419.

Of these, the light source device 413 is a light source lamp 411 as a radiation light source for emitting radial rays.
And a reflector 412 that reflects the radiated light emitted from the light source lamp 411. A halogen lamp, a metal halide lamp, or a high-pressure mercury lamp is often used as the light source lamp 411. A parabolic mirror is used as the reflector 412. In addition to a parabolic mirror, an ellipsoidal mirror may be used together with a collimating lens (concave lens).

The first lens array 418 has a structure in which small lenses having a substantially rectangular contour when viewed in the optical axis direction are arranged in a matrix. Each small lens splits the light flux emitted from the light source lamp 411 into a plurality of partial light fluxes. The contour shape of each small lens is the liquid crystal panel 44.
It is set so as to be substantially similar to the shape of the first image forming area. For example, if the aspect ratio (ratio of horizontal and vertical dimensions) of the image forming area of the liquid crystal panel 441 is 4: 3, the aspect ratio of each small lens is also set to 4: 3.

The second lens array 414 has substantially the same structure as the first lens array 418, and has a structure in which small lenses are arranged in a matrix. The second lens array 414, together with the first condenser lens 416 and the second condenser lens 419, has a function of forming an image of each small lens of the first lens array 418 on the liquid crystal panel 441.

The polarization conversion element 415 is arranged between the second lens array 414 and the first condenser lens 416 and is unitized with the second lens array 414. Such a polarization conversion element 415 has a second
The light from the lens array 414 is converted into one type of polarized light, which improves the light utilization efficiency of the optical device 44.

Specifically, the polarization conversion element 415 sets 1
The respective partial lights converted into the polarized light of the types are finally passed through the first condenser lens 416 and the second condenser lens 419, and finally the liquid crystal panels 441R and 441 of the optical device 44.
It is almost superimposed on G, 441B. In the projector 1 (optical device 44) of the present embodiment using the liquid crystal panel 441 that modulates polarized light, since only one type of polarized light can be used, the light source lamp 411 that emits another type of randomly polarized light is used. Almost half of the light is unused. Therefore, by using the polarization conversion element 415, all the emitted light from the light source lamp 411 is converted into one type of polarized light,
The use efficiency of light in the optical device 44 is improved. Note that such a polarization conversion element 415 is disclosed in, for example, Japanese Patent Laid-Open No. 8-3.
No. 04739.

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

The relay optical system 43 includes an incident side lens 43.
1, relay lens 433, and reflection mirrors 432, 4
34, and has a function of guiding the color light and blue light separated by the color separation optical system 42 to the liquid crystal panel 441B.

At this time, in the dichroic mirror 421 of the color separation optical system 42, the blue light component and the green light component of the luminous flux emitted from the integrator illumination optical system 41 are transmitted and the red light component is reflected. The red light reflected by the dichroic mirror 421 is reflected by the reflection mirror 42.
The light is reflected at 3 and passes through the field lens 417 to reach the red liquid crystal panel 441R. This field lens 4
Reference numeral 17 converts each partial light flux emitted from the second lens array 414 into a light flux parallel to the central axis (chief ray) thereof. The same applies to the field lens 417 provided on the light incident side of the other liquid crystal panels 441G and 441B.

Of the blue light and the green light transmitted through the dichroic mirror 421, the green light is reflected by the dichroic mirror 422, passes through the field lens 417, and reaches the liquid crystal panel 441G for green. On the other hand, the blue light passes through the dichroic mirror 422, passes through the relay optical system 43, and further passes through the field lens 417 to reach the liquid crystal panel 441B for blue light. The reason why the relay optical system 43 is used for blue light is that the optical path length of blue light is longer than the optical path lengths of other color lights, so that reduction in light utilization efficiency due to light diffusion or the like is prevented. This is because. That is, the partial light flux that has entered the incident side lens 431 is directly transmitted to the field lens 417.

The optical device 44 is provided with three liquid crystal panels 441R, 441G and 441B as light modulators and a cross dichroic prism 443 as a color synthesizing optical system. Liquid crystal panels 441R, 441G, 441B
Is a device using, for example, a polysilicon TFT as a switching element, and each color light separated by the color separation optical system 42 is generated by these three liquid crystal panels 441R and 441.
The G, 441B and the polarizing plates 442 on the light incident side and the light emitting side of these G and 441B are modulated according to image information to form an optical image.

The cross dichroic prism 443 is
A color image is formed by synthesizing images modulated for each color light emitted from the three liquid crystal panels 441R, 441G, and 441B. In the cross dichroic prism 443, a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a substantially X shape along the interfaces of the four rectangular prisms. Three color lights are combined by the dielectric multilayer film. Then, the color image combined by the prism 443 is the projection lens 4
It is emitted from 6 and is enlarged and projected on the screen.

Each of the optical systems 41 to 44 described above is housed in a light guide 47 as a housing made of synthetic resin, as shown in FIGS. This light guide 4
7 is each of the above-mentioned optical components 414 to 419, 421 to 42
Each of the lower light guides 471 is provided with a groove portion into which the 3,431 to 434 are slidably fitted from above, and a lid-shaped upper light guide 472 that closes the upper opening side of the lower light guide 471. . Also, the plane is approximately U
The light source device 413 is provided at one end of the character light guide 47.
And a projection lens 46 is fixed to the other end side via a head section 49. In addition, in the head portion 49,
In addition to the projection lens 46, liquid crystal panels 441R and 441
G, 441B and cross dichroic prism 44
The optical device 44 composed of 3 is fixed.

[3. Structure of Optical Device and Attachment Structure to Light Guide] The structure of the optical device 44 will be described below. 8 and 9, the optical device 44 is fixed to the liquid crystal panels 441R, 441G and 441B, the cross dichroic prism 443, and the upper and lower surfaces of the cross dichroic prism 443 (a pair of end surfaces that are substantially orthogonal to the light flux incident end surface). Upper pedestal 444 and lower pedestal 445, and each liquid crystal panel 441R, 441G, 4
A holding frame 446 for holding 41B in the frame, and an upper pedestal 44
4 and the lower pedestal 445 are attached to the holding frame 446.
And a holding member 447 for holding.
Note that in FIG. 8 and FIG. 9, three liquid crystal panels 441 are provided.
Of (441R, 441G, 441B), only the liquid crystal panel 441G is shown as a representative and the other liquid crystal panels 441 are shown.
Illustration of R and 441B is omitted. Where the upper pedestal 44
4, lower pedestal 445, holding frame 446, and holding member 4
47 is formed of a material having a high thermal conductivity such as magnesium alloy, aluminum, or copper.

The upper pedestal 444 and the lower pedestal 445 are
The cross dichroic prism 443 is fixed to both upper and lower surfaces, the outer peripheral shape thereof is slightly larger than that of the cross dichroic prism 443, and the side surface thereof protrudes from the side surface of the cross dichroic prism 443. In addition, recesses 444A and 445A are formed on the side surfaces of the upper pedestal 444 and the lower pedestal 445 over the opposite upper and lower edges, and a driver or the like is provided between the holding member 447 that is adhesively fixed and the upper pedestal 444 and the lower pedestal 445. You can insert the tool. Further, integrated optical devices 44 are provided at the four corners of the upper pedestal 444 to the lower light guide 4.
Four mounting portions 444B for fixing to 71 are provided respectively, and each mounting portion 444B projects laterally from the upper pedestal 444.

Holding members 447 are provided at the four corners of the holding frame 446.
Four mounting holes 446A for mounting on the are formed. A light-shielding film (not shown) is provided on the surface of the holding frame 446 on the light flux emission side, which prevents the reflected light from the cross dichroic prism 443 from being further reflected to the cross dichroic prism 443 side and causes stray light. I try to prevent the contrast from decreasing.

The holding member 447 holds and fixes the holding frame 446 to the cross dichroic prism 443, and includes a frame body 447A and four pins 447B projecting from four corners of the frame body 447A. There is. Holding member 4
A concave portion 447C is formed so as to surround the opening of the frame body 447A on the surface opposite to the surface on which the pin 447B of 47 is protruded, or on the same surface, and the polarized light is polarized to engage with the concave portion 447C. The plate 442 is adhered and fixed. Frame 4
A light-shielding film (not shown) is provided on the surface of 47 A on the light beam exit side, as with the holding frame 446. Such a holding member 447 holds the holding frame 446 by inserting the tip of the pin 447B into the mounting hole 446A of the holding frame 446. Further, the holding member 447 is in a state of straddling the upper pedestal 444 and the lower pedestal 445, and each recess 444A of the upper pedestal 444 and the lower pedestal 445,
It is adhered and fixed to the upper pedestal 444 and the lower pedestal 445 while straddling 445A.

In FIG. 10, such a liquid crystal panel 4 is used.
41 and the cross dichroic prism 443. The optical device 44 includes four mounting portions 44 of the upper pedestal 444.
4B are fixed to the four mounting portions 473 of the lower light guide 471, so that they are mounted to the lower light guide 471. The four mounting portions 473 of the lower light guide 471 are provided on the upper portions of four boss portions 476 each having a substantially columnar shape and continuous in the substantially vertical direction of the lower light guide 471. In addition, these four bosses 476
Are arranged corresponding to the arrangement of the four mounting portions 473 of the optical device 44. Of the four mounting portions 444B of the optical device 44, the two mounting portions 444B arranged on a substantially diagonal line are mounted by being fitted to the mounting portion 473 of the lower light guide 471. The remaining two mounting portions 444B of the optical device 44 are attached to the lower light guide 471.
It is attached by being screwed to the attachment portion 473 of. As described above, when the mounting portion 444B of the upper pedestal 444 is mounted on the mounting portion 473 of the lower light guide 471, the liquid crystal panels 441R, 441G, 441B and the cross dichroic prism 443 are suspended below the upper pedestal 444. The lower light guide 471 is accommodated in the light guide 47 in a state of being slightly floated from the bottom surface of the lower light guide 471.

Here, in the upper light guide 472,
As shown in FIG. 11, an opening 472A is formed in a portion corresponding to above the installation position of the optical device 44. The mounting portion 473 of the lower light guide 471 is exposed to the outside through the opening 472A. As a result, the optical device 44 includes the lower light guide 471 and the upper light guide 47.
Even when the two are fixed to each other, the optical device 44
Mounting portion 444B of the lower light guide 471
It can be attached to and detached from 3. That is, the optical device 44 can be attached to and detached from the light guide 47.

[4. Cooling Structure] In the projector 1 of the present embodiment, the panel cooling system A that mainly cools the liquid crystal panels 441R, 441G, and 441B, the light source cooling system B that mainly cools the light source device 413, and the power source 31 are mainly cooled. A power supply cooling system C and a panel / prism cooling system D having a cooling device 70 are provided.

2, 4, and 5, in the panel cooling system A, a sirocco fan 51 arranged on the right side of the projection lens 46 in FIG. 4 is used. Sirocco fan 51
The cooling air sucked from the intake port 231B on the lower surface is guided to below the optical device 44 through the duct 56 (FIG. 5). Here, in the bottom surface of the lower light guide 471 and the duct 56, the openings 47 are respectively provided at positions corresponding to the lower sides of the liquid crystal panels 441 of the optical device 44.
1C and 56A are formed. Thereby, the cooling air sucked by the sirocco fan 51 is used to cool the liquid crystal panel 441.
The R, 441G, 441B and the polarizing plates 442 arranged on the light incident side and the light emitting side are cooled. In addition, on the lower surface of the lower light guide 471, a plate-shaped straightening plate 478 having a substantially planar shape is provided, and a pair of rising pieces 478A (six pieces in total) provided on the straightening plate 478 are located above the opening 471C from above. It is designed to stick out. However, in FIG. 11, the rising piece 478A is indicated by a chain double-dashed line. By these rising pieces 478A, the liquid crystal panel 441
The flow of the cooling air for cooling the R, 441G, 441B and the polarizing plate 442 is adjusted from the lower side to the upper side.

The cooling air of the panel cooling system A cools the liquid crystal panels 441R, 441G and 441B from the lower side to the upper side in this way, and then cools the lower surface of the driver board 90 (FIG. 3) to the front corner portion. Axial exhaust fan 5
3 and is exhausted from the exhaust port 212B on the front side. Here, the cooling air by the panel cooling system A not only has a role of cooling the liquid crystal panels 441R, 441G, 441B, but is also blown onto the surfaces of the liquid crystal panels 441R, 441G, 441B, so that dust and the like attached to the panel surfaces. It also has a role to blow away. By the panel cooling system A, the surfaces of the liquid crystal panels 441R, 441G, 441B can be constantly cleaned, so that the projector 1 can transmit an optical image of stable image quality onto a screen or the like.

4 to 6, in the light source cooling system B,
Sirocco fan 54 provided on the lower surface of the optical unit 4.
Is used. The cooling air in the projector 1 attracted by the sirocco fan 54 enters into the light guide 47 through an opening (not shown) provided in the upper light guide 472, and the space between the second lens array 414 and the polarization conversion element 415 which are unitized. After cooling them through the through holes, the exhaust side opening 471 of the lower light guide 471 is opened.
After being discharged from A, it is sucked by the sirocco fan 54 and discharged. The exhaled cooling air is supplied to the lower light guide 471.
From the intake side opening 471B into the light guide 47 again, and then into the light source device 413 to cool the light source lamp 411, and then exit from the light guide 47 and, like the panel cooling system A, the axial exhaust fan. Exhaust port 2 by 53
Exhausted from 12B.

In FIG. 4, in the power supply cooling system C, the power supply 3
The axial-flow intake fan 55 provided behind 1 is used. Axial flow intake fan 55 allows rear side intake port 2D
After cooling the power supply 31 and the lamp drive circuit 32, the cooling air sucked in from the cooling air, like the other cooling systems A and B,
It is exhausted from the exhaust port 212B by the axial exhaust fan 53.

In FIGS. 1, 4, and 5, the panel / prism cooling system D uses the cooling device 70 as described above. The cooling device 70 includes a cooling device body 71 attached to the optical device 44 and a projection lens 46 shown in FIG.
And an axial fan 72 arranged on the left side of the center. The cooling device main body 71, as shown in FIG.
Plate 711 attached to the upper surface of the upper pedestal 444 of the
And two heat pipes 712 as heat conducting members each having one end connected to the heat receiving plate 711, a heat radiating plate 713 connected to the other end of each heat pipe 712, and a Peltier module to which the heat radiating plate 713 is attached. 714 and are included. Of these, the heat receiving plate 711 and the heat radiating plate 713 are formed of a material having a high thermal conductivity such as magnesium alloy, aluminum, or copper. The Peltier module 714 and the axial fan 72 form the cooling mechanism according to the present invention.

The heat pipe 712 is formed in a tubular shape,
This tube is made of a material having a high thermal conductivity such as copper or a copper alloy. The cross-sectional shape of the tube may be a substantially circular shape, a quadrangular shape, or a substantially I-shape in which the tube is crushed to be flat. The inside of the heat pipe 712 is in a low-pressure state (substantially vacuum state), and a refrigerant (working liquid) such as water, CFC substitute, alcohol, etc. is accommodated therein.
In addition, a so-called wick (capillary structure) is formed by attaching a mesh-shaped metal mesh to the inner peripheral surface of the tube or forming innumerable grooves (grooves) along the longitudinal direction of the tube.
Are formed. In the heat pipe 712 having such a configuration, when one end side is heated, the internal refrigerant evaporates, and the generated vapor moves to the other end side through substantially the center inside the pipe. Here, when the other end of the heat pipe 712 is cooled from the outside, the vapor that has moved to the other end condenses to release latent heat. The condensed refrigerant returns to the one end side of the heat pipe 712 by the capillary force of the wick on the inner peripheral surface of the tube. The refrigerant is the heat pipe 712.
Is heated again at one end of the and evaporated. By repeating this process, a large amount of heat can be transferred.

Here, the heat transfer amount of the heat pipe 712 varies depending on the type of wick on the inner peripheral surface thereof, the outer diameter (inner diameter) of the pipe, the operating temperature thereof, the inclination of the pipe at the time of installation, and the like. Therefore, it is necessary to decide the type of heat pipe, the installation posture, etc. in consideration of these. Specifically, in the present embodiment, for example, the type and installation posture of the heat pipe are determined based on the graphs of FIGS. 13A and 14.

In the graph of FIG. 13A, the vertical axis represents the maximum heat transport amount Qmax.Leff [W.m], and the horizontal axis represents the inclination angle α [°] of the heat pipe. The operating temperature Tw (that is, the heating temperature for heating one end of the heat pipe) is set to 50 ° C. Leff [m] is shown in FIG.
As shown in FIG. 3 (B), in the heat pipe, the length of the heating portion (heated portion) is Le [m], the length of the heat insulating portion (portion where heating and cooling is not performed) is La [m], and heat radiation is performed. When the length of the part (the part to be cooled) is Lc [m], it is expressed by the following formula. Leff = (Le + Lc) / 2 + La Further, the inclination angle α of the pipe is the inclination angle from the horizontal plane in the state where the heating portion is arranged below and the heat radiating portion is arranged above (see FIG. 13B). In the graph of FIG. 13A, the line (1) is a heat pipe having an outer diameter of 3 mm and a wick formed of a mesh-shaped metal mesh, and the line (2) is an outer diameter of 3 mm. In the case of the heat pipe having a substantially cylindrical shape and having a groove, the line (3) is a heat pipe having a flat shape and a groove having a height of 2 mm formed by crushing a substantially cylindrical pipe having an outer diameter of 3 mm. In this case, the line (4) is a heat pipe with a groove having a flat shape with a height of 1.5 mm formed by crushing a substantially cylindrical pipe having an outer diameter of 3 mm, and (5)
The respective lines indicate the case of a heat pipe having a groove having a flat shape with a height of 1.2 mm formed by crushing a substantially cylindrical pipe having an outer diameter of 3 mm.

According to this graph, it can be seen that the maximum heat transport amount Qmax · Leff can be increased by making the inclination angle α of the heat pipe as close as possible to 90 °. Therefore, the heating portion of the heat pipe should be arranged as low as possible. ,
It is desirable to arrange the heat dissipation part as high as possible. Further, it can be seen that the maximum heat transport amount Qmax · Leff can be made larger when the wick of the heat pipe is formed of a mesh-shaped metal net than when it is formed of a groove. However, when forming a wick with a mesh-shaped metal net,
Since the metal net is attached to the inner peripheral surface of the pipe, it is difficult to crush a substantially cylindrical pipe into a flat shape in the heat pipe. On the other hand, when the wick is formed by the groove, since the groove is directly formed on the inner peripheral surface of the pipe, it is easy to form the heat pipe in a flat shape. Therefore, when it is preferable that the shape of the heat pipe is flat due to the problem of installation space, it is desirable to use the heat pipe in which the wick is formed by the groove. Furthermore, in the case of a flat heat pipe, it can be seen that the smaller the height dimension thereof, the smaller the maximum heat transport amount Qmax · Leff. It is desirable to adopt a heat pipe having a shape close to the shape.

On the other hand, in the graph of FIG. 14, the vertical axis represents the maximum heat transport amount Qmax · Leff [W · m], the horizontal axis represents the operating temperature Tw [° C] of the heat pipe, and each line is
The case where the pipe has an outer diameter of 6 mm, 4 mm, and 3 mm is shown. The heat pipes having different outer diameters are substantially the same under other conditions. The heat pipes have a substantially cylindrical shape and a wick is formed by a groove, and the inclination angle α of the pipe is zero [°]. . According to this graph, the higher the operating temperature Tw, the higher the maximum heat transfer amount Q
Since it can be seen that max.Leff is large, it is preferable to select the type of heat pipe according to the amount of heat generated by the optical device 44 cooled by the cooling device 70 and the like. Also, the larger the outer diameter of the pipe, the larger the maximum heat transfer amount Qm.
Since it can be seen that ax · Leff is large, it is desirable to use a heat pipe having a pipe outer diameter as large as possible when the installation space has a certain margin.

As described above, based on various judgment factors,
If the type, outer diameter, length, posture, etc. of the heat pipe are determined, the maximum heat transfer amount Qmax / Lef by the heat pipe
Since f can be set to a large value, the cooling efficiency of the optical device 44 by the cooling device 70 can be improved.

Although not shown, the Peltier module 714 has a plurality of bonding pairs formed by bonding a p-type semiconductor and an n-type semiconductor with metal pieces, and these plurality of bonding pairs are electrically connected in series. It is connected to the. In this joint pair,
When a direct current is passed from the n-type semiconductor to the p-type semiconductor, the metal piece is cooled and heat can be taken from the surroundings.
Conversely, when a direct current is passed from the p-type semiconductor to the n-type semiconductor, the metal piece is heated and heat can be released to the surroundings. Peltier module 71 having such a configuration
4, when a direct current is applied, the Peltier module 7
One surface of 14 is a heat absorbing portion that absorbs heat, and the other surface is a heat generating portion that is generated. It is possible to switch between the heat absorbing portion and the heat generating portion by changing the direction of the electric current. In this embodiment, the DC current flowing through the Peltier module 714 is fixed in one direction,
14 endothermic portion 714A and exothermic portion 714B
Is fixed. A heat radiating plate 713 is attached to the heat absorbing portion 714A of the Peltier module 714, and a fin 714C is fixed to the heat generating portion 714B in order to improve the heat radiating effect.

Such a Peltier module 714 is
As shown in FIGS. 4 and 5, it is arranged between the projection lens 46 and the exhaust port 2F, and faces the sirocco fan 51 with the projection lens 46 in between. The axial fan 72 is arranged between the Peltier module 714 and the exhaust port 2F,
From the Peltier module 714 to the exhaust port 2F,
It is designed to suck and exhaust air. Here, in the Peltier module 714, the heat absorbing part 714A is arranged on the projection lens 46 side, and the heat generating part 714B is the axial fan 7.
It is located on the second side. As a result, the heat generating portion 714B
The heat generated in 1 does not adversely affect the projection lens 46.

The operation of the panel / prism cooling system D will be described below. When the light emitted from the light source device 413 is guided to the optical device 44, the liquid crystal panel 441, the polarizing plate 442, and the cross dichroic prism 443 generate heat due to the transmission and reflection of the light. The heat generated by these optical elements 441, 442, 443 is generated by the upper pedestal 444 and the lower pedestal 4 as indicated by the black arrow in FIG.
It moves to the heat receiving plate 711 through 45, the holding frame 446, and the holding member 447, and then to the one end side of the heat pipe 712. The upper pedestal 444 and the lower pedestal 4
The holding device 45, the holding frame 446, and the holding member 447 form the optical device 44 and also serve as the contact member according to the present invention. Here, since the upper pedestal 444, the lower pedestal 445, the holding frame 446, and the holding member 447 are made of a material having high thermal conductivity as described above, the heat from each of the optical elements 441, 442, 443 is reduced. The movement becomes quicker, and the optical elements 441, 44
Heat will not be accumulated in 2,443. On the other hand, the cooling air of the panel cooling system A flows toward the liquid crystal panel 441 and the polarizing plate 442 from the lower side to the upper side to cool the liquid crystal panel 441 and the polarizing plate 442 as shown by the white arrow in FIG. Clean it.

The heat that has moved to one end of the heat pipe 712 moves to the other end of the heat pipe 712 due to the internal coolant, and moves from the other end to the heat dissipation plate 713.
Then, the heat of the heat dissipation plate 713 is transferred to the Peltier module 71.
The optical device 44 is cooled by the cooling device 70 by being absorbed by the heat absorbing portion 714 </ b> A of No. 4.

On the other hand, in the Peltier module 714, when a direct current flows, the heat absorbing portion 714A absorbs heat and the heat generating portion 714B releases heat.
The heat generation portion 714B is cooled by heat radiation by the fins 714C and blowing of cooling air by the axial fan 72. Here, the axial fan 72 is shown in FIG.
As shown in, the cooling air is sucked into the projector 1 from the intake port 231B of the lower case 23, and the intake port 2
Peltier module 7 between 31B and axial fan 72
Since 14 is arranged, the Peltier module 71
The cooling air is blown to the four fins 714C. After cooling the Peltier module 714,
The cooling air is discharged to the outside from the exhaust port 2F by the axial fan 72. In this way, the Peltier module 71
By immediately discharging the cooling air that has cooled the cooling unit 4 to the outside through the exhaust port 2F, it is possible to prevent heat from being trapped inside the projector 1 and to further improve the cooling efficiency.

According to this embodiment as described above, the following effects can be obtained. In the present embodiment, in the optical device 44, both the panel cooling system A and the panel / prism cooling system D perform cooling, so that the cooling efficiency can be improved,
The life of the optical device 44 can be extended.

In the panel / prism cooling system D, since the optical device 44 is cooled by the heat transfer using the heat pipe 712, the liquid crystal panel 441 which is difficult to cool with the cooling air due to the narrow space between the optical elements, the polarized light. The plate 442 and the cross dichroic prism 443 can be reliably cooled, and the optical elements 441, 442
The deterioration of 443 can be prevented.

Since the Peltier module 714 is used in the cooling device 70, heat can be positively absorbed from the other end side of the heat pipe 712 via the heat dissipation plate 713, and the cooling efficiency of the optical device 44 can be improved. You can Furthermore, the heat generating portion 71 of the Peltier module 714
Since the axial fan 72 for blowing the cooling air is provided in the 4B, it is possible to avoid the temperature rise due to the heat generation when the Peltier module 714 is used. Also, the Peltier module 714
Since the fins 714C are attached to the heat generating portion 714B, the cooling efficiency can be improved.

Since the heat pipe 712 is employed as the heat conducting member in the cooling device 70, heat can be quickly transferred from the optical device 44 to the Peltier module 714.
The cooling efficiency of the optical device 44 can be made very good.

Since the upper pedestal 444, the lower pedestal 445, the holding frame 446, and the holding member 447, which are contact members, and the heat receiving plate 711 are made of a material having a high thermal conductivity,
The heat generated in the liquid crystal panel 441, the polarizing plate 442, and the cross dichroic prism 443 can be quickly transferred to the heat pipe 712, and the cooling efficiency can be improved. Here, if the polarizing plate 442 has a structure in which sapphire glass having high thermal conductivity is used as a substrate and the polarizing film is attached to the substrate with a transparent adhesive, the cooling efficiency can be further improved.

In the cooling device 70, the axial fan 72 and the Peltier module 714 are arranged beside the projection lens 46 which usually has an empty space, and the heat pipe 71 is provided.
2 the heat of the optical device 44 by the Peltier module 71
Since it is configured to lead up to 4, it is possible to eliminate the need for a major design change of the projector 1 by using the cooling device 70. Moreover, since the Peltier module 714 can be installed in the empty space inside the projector 1 by arbitrarily guiding the heat of the optical device 44 with the heat pipe 712, the installation space of the Peltier module 714 does not have to be created near the optical device 44. In addition, the degree of freedom in designing the projector 1 is increased, and the projector 1 can be easily downsized.

[Second Embodiment] FIGS. 16 and 17 show a second embodiment of the present invention. In the second embodiment, the panel cooling system A and the panel / prism cooling system D are used for cooling the optical device 44 in the first embodiment.
What was done in both, without installing the panel cooling system A,
The optical device 44 is cooled only by the panel / prism cooling system D. That is, in the panel / prism cooling system D, as shown in FIG. 17, the Peltier module 714 and the axial fan 72 are connected to the projection lens 4
They are opposed to each other with 6 in between. Of the Peltier module 714 and the axial fan 72, the axial fan 7
2 is disposed near the exhaust port 2F. In addition, as shown in FIG. 16, in the front part 214 of the upper case 21, which is in the vicinity of the Peltier module 714, a large number of intake ports 2 are provided.
G is formed. In this embodiment, the intake port 231B on the bottom surface of the lower case 23 is not provided. In the panel / prism cooling system D having such a configuration,
By the axial fan 72, the intake port 2 on the front of the exterior case 2
The cooling air is sucked from G, and the Peltier module 714
Is cooled, and thereafter, cooling air is discharged from the exhaust port 2F.

Also in the second embodiment as described above, the same operation and effect as those of the first embodiment can be obtained, and the panel cooling system A is eliminated, and the sirocco fan 51,
Since the duct 56 and the current plate 478 are unnecessary, the number of parts can be reduced and the cost can be reduced.
The effect can be added.

The present invention is not limited to the above-mentioned embodiment, and modifications and improvements within a range in which the object of the present invention can be achieved are included in the present invention. For example,
In each of the above-described embodiments, the heat receiving plate 711 of the cooling device 70 is
Although attached to the upper pedestal 444 of the optical device 44, as shown in FIG.
It may be attached to the lower surface of the lower pedestal 445 of the optical device 44 as shown in FIG. In such a case, since the inclination angle α of the heat pipe 712 that connects the heat receiving plate 711 and the heat radiating plate 713 can be made large, the maximum heat transport amount Qmax · Leff of the heat pipe 712 can be made larger. The cooling efficiency of the optical device 44 by the cooling device 70 can be further improved.

Although two heat pipes 712 are used in each of the above embodiments, the number of heat pipes 712 connecting the heat receiving plate 711 and the heat radiating plate 713 may be one.
Alternatively, it may be three or more. However, the larger the number of heat pipes, the larger the heat transfer amount from the optical device to the Peltier module. Therefore, if the heat transfer amount per heat pipe is small due to the small pipe diameter, etc., provide multiple heat pipes. Is desirable.

The fan for blowing the cooling air to the heat generating portion of the Peltier module is not limited to the axial fan, but a centrifugal fan such as a sirocco fan may be used. Further, the fan is not necessarily provided, and when the fan is not provided, the heat generating portion of the Peltier module is arranged in the vicinity of the exhaust port 2F of the projector 1 so that the heat generated in the heat generating portion is not accumulated inside the projector 1. You can avoid it.

In the first embodiment, the optical device 44 is
Although cooling is performed by both the panel cooling system A and the panel / prism cooling system D, the optical device 44 may be cooled only by the panel / prism cooling system D without providing the panel cooling system A. In such a case, the sirocco fan 51, the duct 56, and the rectifying plate 478 are unnecessary, so that the second
The same effect as the embodiment can be obtained.

The heat conducting member in which the refrigerant circulates inside the tube is not limited to the heat pipe utilizing the capillary phenomenon for the circulation of the refrigerant, but a thermosyphon utilizing gravity may be adopted.
However, when the thermosyphon is adopted, the inclination angle α must be attached to the thermosiphon, so that the design flexibility is increased by using the heat pipe that does not necessarily require the inclination angle α.

The cooling mechanism is not limited to a combination of a Peltier module and a fan, but may be a combination of a fin connected to the other end of the heat conducting member and a fan for blowing cooling air to the fin. Good. Further, the cooling mechanism is not limited to one having a means (fan or the like) for blowing a refrigerant to the other end side of the heat conducting member, but a heat radiating means (fin or the like) connected to the other end side of the heat conducting member for radiating heat. You may employ the thing provided with. Such a heat radiating means is not limited to the fins and the Peltier module, but the upper shield plate 81 included in the projector 1 is provided.
(See FIG. 3) is taken as an example. In such cases,
As shown in FIG. 19, by connecting the other end of the heat pipe 712 to the lower surface of the upper shield plate 81, the heat generated in the optical device 44 moves to the entire upper shield plate 81 via the heat pipe 712. Like As a result, the heat of the optical device 44 is radiated over the entire surface of the upper shield plate 81 having a large area, and the optical device 44 can be cooled. The heat pipe 712 is connected to the lower shield plate 84.
(See FIG. 5), the heat pipe 712 is preferably connected to the upper shield plate 81 in order to have a certain inclination angle α. Furthermore, as the heat dissipation means described above, not only the shield plate,
When the outer case of the projector is made of metal, the outer case may be adopted.

The arrangement of the cooling mechanism is not limited to the side of the projection lens, but if there is a space where the cooling mechanism can be installed,
It can be placed in any space. The object to be cooled is not limited to the optical device 44, and may be the light source device 413, the polarization conversion element 415, or another optical element,
In short, any optical element can be used as long as it generates heat by transmitting or reflecting light. Further, the cooling device of the present invention is not limited to the one applied to the optical element of the projector, but may be applied to the optical element of various other optical devices, and such a case is also included in the present invention. Be done.

[0077]

According to the cooling device of the present invention and the projector provided with the same, it is possible to improve the cooling efficiency of the optical element and to facilitate miniaturization of the optical device including the optical element. effective.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a projector according to a first embodiment of the present invention as seen from above.

FIG. 2 is an overall perspective view of the projector according to the first embodiment seen from below.

FIG. 3 is a perspective view showing a state in which an upper case is removed from the state of FIG.

4 is a perspective view of the upper shield plate, the driver board, and the upper light guide removed from the state of FIG. 3 as seen from the rear side.

5 is a perspective view showing a state in which the optical unit is removed from the state of FIG.

FIG. 6 is a perspective view of the optical unit according to the first embodiment as viewed from below.

FIG. 7 is a plan view schematically showing the optical unit according to the first embodiment.

FIG. 8 is a perspective view showing an optical device according to the first embodiment.

FIG. 9 is an exploded perspective view showing the optical device according to the first embodiment.

FIG. 10 is an exploded perspective view showing a lower light guide and an optical device in the first embodiment.

FIG. 11 is a plan view showing an optical unit according to the first embodiment.

FIG. 12 is a perspective view showing a cooling device and an optical device in the first embodiment.

FIG. 13A is a graph showing the relationship between the maximum heat transport amount in various heat pipes and the inclination angle of the pipe,
(B) is a schematic diagram for defining the inclination angle of the heat pipe.

FIG. 14 is a graph showing the relationship between the maximum heat transport amount and operating temperature in various heat pipes.

FIG. 15 is a sectional view showing how heat is transferred in the optical device according to the first embodiment.

FIG. 16 is an overall perspective view of a projector according to a second embodiment of the present invention as seen from above.

FIG. 17 is a perspective view of the upper case, the upper shield plate, the driver board, and the upper light guide removed from the state of FIG. 16 as seen from the rear side.

FIG. 18 is a perspective view showing a main part of a modified example of the present invention.

FIG. 19 is a perspective view showing a main part of another modification of the present invention.

[Explanation of symbols]

1 Projector 46 Projection Lens 70 Cooling Device 72 Axial Flow Fan (Cooling Mechanism) 81 Upper Shield Plates 441, 441R, 441G, 441B Liquid Crystal Panel (Optical Element) 442 Polarizing Plate (Optical Element) 443 Cross Dichroic Prism (Optical) Element 444 Upper pedestal (contact member) 445 Lower pedestal (contact member) 446 Holding frame (contact member) 447 Holding member (contact member) 711 Heat receiving plate (contact member) 712 Heat pipe 714 Peltier module (cooling mechanism) ) 714A endothermic part 714B exothermic part

Claims (9)

[Claims] 1. A cooling device for cooling an optical element, comprising: a contact member that contacts the optical element; one end side of which is connected to the contact member; and a heat conducting member that guides heat of the contact member to the other end side. And a cooling mechanism for forcibly cooling the other end of the heat conducting member. 2. The cooling device according to claim 1, wherein the cooling mechanism includes a Peltier module that utilizes a Peltier effect, and the heat absorbing portion of the Peltier module that absorbs heat is the other end side of the heat conducting member. A cooling device characterized by being connected to. 3. The cooling device according to claim 2, wherein the cooling mechanism includes a fan that blows cooling air to a heat generating portion of the Peltier module that generates heat. 4. The cooling device according to claim 1, wherein the cooling mechanism includes a fin connected to the other end side of the heat conducting member, and a fan that blows cooling air to the fin. Cooling device characterized by being. 5. The cooling device according to claim 1, wherein the heat-conducting member is formed in a tubular shape, and a refrigerant is accommodated inside the tube, and the refrigerant flows inside the tube. The cooling device is characterized in that heat is transferred in the heat conducting member by being circulated. 6. The cooling device according to claim 1, wherein the contact member is made of a material having a thermal conductivity higher than that of the optical element. . 7. The cooling device according to claim 1, wherein the optical element is at least one of a liquid crystal panel, a polarizing plate, a polarizing beam splitter, and a light source device. A cooling device characterized by being present. 8. A projector comprising the cooling device according to any one of claims 1 to 7. 9. The projector according to claim 8, wherein the cooling mechanism is arranged laterally of the projection lens.