Projector

A projector having a cooling target includes a light source configured to emit light, a light modulator configured to modulate the light emitted from the light source, a projection optical device configured to project the light modulated by the light modulator, a cooler configured to cool the cooling target based on transformation of a refrigerant into a gas, and a controller configured to control the cooler. The cooler includes a refrigerant generator configured to generate the refrigerant, and a refrigerant sender configured to transmit the generated refrigerant toward the cooling target. The controller controls the refrigerant generator based on at least one of temperature of the cooling target and ambient humidity of the projector.

The present application is based on, and claims priority from JP Application Serial Number 2019-130443, filed Jul. 12, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to a projector.

2. Related Art

As a device for cooling a projector, there are proposed such a cooler due to air cooling using a blower as described in, for example, JP-A-2002-107698, such a cooler due to liquid cooling using a pump for feeding a refrigerant liquid and a pipe for transmitting the refrigerant liquid as described in, for example, JP-A-2007-294655, and so on.

In recent years, due to an increase in luminance of projectors, an amount of heat of a cooling target to be cooled by a cooler has increased, and an improvement in cooling performance of the cooler is required. However, when improving the cooling performance in the cooler described above using air cooling, liquid cooling, and so on, there is a problem that the cooler grows in size, and thus the projector grows in size. Further, in the case of air cooling, there is also a problem that the sound noise due to the blower increases.

SUMMARY

A projector according to an aspect of the present disclosure is a projector having a cooling target, including a light source configured to emit light, a light modulator configured to modulate the light emitted from the light source in accordance with an image signal, a projection optical device configured to project the light modulated by the light modulator, a cooler configured to cool the cooling target based on transformation of a refrigerant into a gas, and a controller configured to control the cooler. The cooler includes a refrigerant generator configured to generate the refrigerant, and a refrigerant sender configured to transmit the generated refrigerant toward the cooling target. The controller controls the refrigerant generator based on at least one of temperature of the cooling target and ambient humidity of the projector.

The projector may be configured such that the refrigerant generator includes a rotating moisture absorption/desorption member, a first blower configured to deliver air to first a part of the moisture absorption/desorption member located in a first area, a heat exchanger coupled to the refrigerant sender, a heater configured to heat a second part of the moisture absorption/desorption member located in a second area different from the first area, and a second blower configured to deliver ambient air of the second part heated by the heater in the moisture absorption/desorption member to the heat exchanger. The heat exchanger is cooled to thereby generate the refrigerant from the air flowed into the heat exchanger. The controller controls at least one of an output of the first blower, an output of the heater, and a cooling degree by the heat exchanger based on at least one of the temperature of the cooling target and the ambient humidity of the projector.

The projector may be configured such that the controller changes at least one of the output of the first blower, the output of the heater, and the cooling degree by the heat exchanger when the temperature of the cooling target is out of a target temperature range.

The projector may be configured such that the controller increases at least one of the output of the first blower, the output of the heater, and the cooling degree by the heat exchanger when the temperature of the cooling target is higher than the target temperature range.

The projector may be configured such that the controller decreases at least one of the output of the first blower, the output of the heater, and the cooling degree by the heat exchanger when the temperature of the cooling target is lower than the target temperature range.

The projector may be configured such that the controller changes all of the output of the first blower, the output of the heater, and the cooling degree by the heat exchanger based on the temperature of the cooling target.

The projector may be configured such that the controller changes at least one of the output of the first blower, the output of the heater, and the cooling degree by the heat exchanger when the ambient humidity of the projector is out of a preset humidity range.

The projector may be configured such that, when the ambient humidity of the projector is higher than the preset humidity range, the controller makes at least one of the output of the first blower, the output of the heater, and the cooling degree by the heat exchanger lower than a level set when the ambient humidity of the projector is within the preset humidity range.

The projector may be configured such that, when the ambient humidity of the projector is lower than the preset humidity range, the controller makes at least one of the output of the first blower, the output of the heater, and the cooling degree by the heat exchanger higher than a level set when the ambient humidity of the projector is within the preset humidity range.

The projector may be configured such that the controller controls all of the output of the first blower, the output of the heater, and the cooling degree by the heat exchanger based on the ambient humidity of the projector.

The projector may be configured such that the controller controls the refrigerant generator based on both of the temperature of the cooling target and the ambient humidity of the projector.

The projector may be configured such that the controller gives priority to a control of the refrigerant generator based on the temperature of the cooling target over a control of the refrigerant generator based on the ambient humidity of the projector.

The projector may be configured such that the cooling target is the light modulator.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

A projector according to an embodiment of the present disclosure will hereinafter be described with reference to the drawings. It should be noted that the scope of the present disclosure is not limited to the embodiments hereinafter described, but can arbitrarily be modified within the technical idea or the technical concept of the present disclosure. Further, in the following drawings, in order to make each constituent easy to understand, each of the structures is made different from the actual structure in scale size, number, and so on in some cases.

First Embodiment

FIG. 1is a schematic configuration diagram showing the projector1according to the present embodiment.FIG. 2is a schematic diagram showing a part of the projector1according to the present embodiment. As shown inFIG. 1, the projector1is provided with a light source device2, a color separation optical system3, a light modulation unit4R, alight modulation unit4G, a light modulation unit4B, a light combining optical system5, and a projection optical device6. The light modulation unit4R has a light modulator4RP. The light modulation unit4G has a light modulator4GP. The light modulation unit4B has a light modulator4BP.

The light source device2emits illumination light WL regulated so as to have a substantially homogenous illuminance distribution toward the color separation optical system3. The light source device2has, for example, a semiconductor laser as a light source. The color separation optical system3separates the illumination light WL from the light source device2into red light LR, green light LG, and blue light LB. The color separation optical system3is provided with a first dichroic mirror7a, a second dichroic mirror7b, a first reflecting mirror8a, a second reflecting mirror8b, a third reflecting mirror8c, and a relay lens8d.

The first dichroic mirror7aseparates the illumination light WL having been emitted from the light source device2into the red light LR, and the light including the green light LG and the blue light LB mixed with each other. The first dichroic mirror7ahas a property of transmitting the red light LR, while reflecting the green light LG and the blue light LB. The second dichroic mirror7bseparates the light including the green light LG and the blue light LB mixed with each other into the green light LG and the blue light LB. The second dichroic mirror7bhas a property of reflecting the green light LG, while transmitting the blue light LB.

The first reflecting mirror8ais disposed in the light path of the red light LR, and the red light LR having been transmitted through the first dichroic mirror7ais reflected by the first reflecting mirror8atoward the light modulator4RP. The second reflecting mirror8band the third reflecting mirror8care disposed in the light path of the blue light LB, and the blue light LB having been transmitted through the second dichroic mirror7bis guided by the second reflecting mirror8band the third reflecting mirror8cto the light modulator4BP.

The light modulator4RP, the light modulator4GP, and the light modulator4BP are each formed of a liquid crystal panel. The light modulator4RP modulates the red light LR out of the light emitted from the light source device2in accordance with an image signal. The light modulator4GP modulates the green light LG out of the light emitted from the light source device2in accordance with an image signal. The light modulator4BP modulates the red light LB out of the light emitted from the light source device2in accordance with an image signal. Thus, the light modulators4RP,4GP, and4BP each form image light corresponding to the colored light. Although not shown in the drawings, on the light incident side and the light exit side of each of the light modulators4RP,4GP, and4BP, there are respectively disposed polarization plates.

On the light incident side of the light modulator4RP, there is disposed a field lens9R for collimating the red light LR entering the light modulator4RP. On the light incident side of the light modulator4GP, there is disposed a field lens9G for collimating the green light LG entering the light modulator4GP. On the light incident side of the light modulator4BP, there is disposed a field lens9B for collimating the blue light LB entering the light modulator4BP.

The color combining optical system5is formed of across dichroic prism having a substantially cubic shape. The light combining optical system5combines the image light of the respective colors from the light modulators4RP,4GP, and4BP with each other. The light combining optical system5emits the image light thus combined toward the projection optical device6. The projection optical device6is formed of a projection lens group. The projection optical device6projects the image light combined by the light combining optical system5, namely the light modulated by the light modulators4RP,4GP, and4BP, toward a screen SCR in an enlarged manner. Thus, a color image (picture) thus enlarged is displayed on the screen SCR.

As shown inFIG. 2, the projector1is further provided with a cooler10. The cooler10cools a cooling target provided to the projector1by a refrigerant W changing to a gas. In the present embodiment, the refrigerant W is, for example, water as a fluid. Therefore, in the following description, the change of the refrigerant W to the gas is simply referred to as evaporation in some cases. In the present embodiment, the cooling target includes the light modulation units4R,4G, and4B. In other words, in the present embodiment, the cooling target includes the light modulators4RP,4GP, and4BP.

The cooler10has a refrigerant generator20and a refrigerant sender50. The refrigerant generator20is a section for generating the refrigerant W. The refrigerant sender50is a section for transmitting the refrigerant W thus generated toward the cooling target. Due to the evaporation of the refrigerant W having been transmitted by the refrigerant sender50to the cooling target, namely the light modulation units4R,4G, and4B in the present embodiment, it is possible to draw the heat from the cooling target, and thus, it is possible for the cooler10to cool the cooling target. Each of the sections will hereinafter be described in detail.

FIG. 3is a schematic configuration diagram schematically showing a refrigerant generator20in the present embodiment. As shown inFIG. 3, the refrigerant generator20has a moisture absorption/desorption member40, a motor (a driver)24, a first blower (a cooling blower)60, a heat exchanger30, a circulation duct25, a circulation duct26, a heater22, a second blower23, a cooling duct21.

FIG. 4is a perspective view showing the moisture absorption/desorption member40. As shown inFIG. 4, the moisture absorption/desorption member40has a flat cylindrical shape centered on a rotational axis R. In a central part of the moisture absorption/desorption member40, there is formed a central hole40ccentered on the rotational axis R. The central hole40cpenetrates the moisture absorption/desorption member40in an axial direction of the rotational axis R. The moisture absorption/desorption member40rotates around the rotational axis R. In the following description, the axial direction of the rotational axis R is referred to as a “rotational axis direction DR,” and is arbitrarily represented by a DR axis in the drawings.

The moisture absorption/desorption member40has an infinitely large number of through holes40bpenetrating the moisture absorption/desorption member40bin the rotational axis direction DR. The moisture absorption/desorption member40is a porous member. The moisture absorption/desorption member40has a moisture absorption/desorption property. In the present embodiment, the moisture absorption/desorption member40is manufactured by, for example, winding a belt-like member40ashaped like a belt and having the through holes40baround the rotational axis R, and then coating a surface exposed outside in the belt-like member40athus wound with a material having a moisture absorption/desorption property. It should be noted that the surface exposed outside in the belt-like member40athus wound includes an outside surface of the moisture absorption/desorption member40, an inner circumferential surface of the central hole40c, and internal surfaces of the through holes40b. It should be noted that the moisture absorption/desorption member40can wholly be made of a material provided with the moisture absorption/desorption property. As the material having the moisture absorption/desorption property, there can be cited, for example, zeolite and silica gel.

An output shaft of the motor24shown inFIG. 3is fixed in a state of being inserted into the central hole40cof the moisture absorption/desorption member40. The motor24rotates the moisture absorption/desorption member40around the rotational axis R. The rotational speed of the moisture absorption/desorption member40rotated by the motor24is, for example, about no lower than 0.2 rpm and no higher than 5 rpm.

The first blower60is, for example, an intake fan for taking external air in the projector1. The first blower60feeds air AR1to apart of the moisture absorption/desorption member40located in a first area F1. The first area F1is an area on one side of the rotational axis R in a direction perpendicular to the rotational axis R. In contrast, in the direction perpendicular to the rotational axis R, an area on the other side of the rotational axis R, namely an area on the opposite side to the first area F1with respect to the rotational axis R, corresponds to a second area F2. The first area F1is an area on the upper side of the rotational axis R inFIG. 3. The second area F2is an area on the lower side of the rotational axis R inFIG. 3.

As shown inFIG. 2, the first blower60feeds the air AR1also to the light modulation units4R,4G, and4B as the cooling target. In other words, in the present embodiment, the first blower60is a cooling blower for feeding the air AR1to the cooling target. The first blower60is not particularly limited providing the first blower60is capable of feeding the air AR1, and can be, for example, an axial fan or a centrifugal fan.

The heat exchanger30is a section where the refrigerant W is generated.FIG. 5is a partial cross-sectional perspective view showing the heat exchanger30. As shown inFIG. 5, the heat exchanger30has a circulation part31, a first lid part32, and a second lid part33.

The circulation part31has a plurality of pipe parts31aeach having a tubular shape extending in one direction. In the present embodiment, the one direction in which the pipe parts31aextend is, for example, perpendicular to the rotational axis direction DR. The pipe parts31aeach open on both sides in the one direction in which the pipe parts31aextend. A shape of a cross-sectional surface of the pipe part31aperpendicular to the one direction in which the pipe parts31aextend is, for example, a circular shape. It should be noted that in the following description, the one direction in which the pipe parts31aextend is referred to as an “extension direction DE,” and is arbitrarily represented by a DE axis in the drawings. The first area F1and the second area F2described above are separated in the extension direction DE perpendicular to the rotational axis direction DR with reference to the rotational axis R.

In the present embodiment, the circulation part31is formed of a plurality of layers each formed of the plurality of pipe parts31aarranged along the rotational axis direction DR stacked along a direction perpendicular to both of the rotational axis direction DR and the extension direction DE. It should be noted that in the following description, the direction perpendicular to both of the rotational axis direction DR and the extension direction DE is referred to as a “thickness direction DT,” and is arbitrarily represented by a DT axis in the drawings. In the present embodiment, the dimension in the thickness direction DT of the circulation part31is smaller than, for example, the dimension in the rotational axis direction DR of the circulation part31, and is the smallest of the dimensions of the circulation part31in the direction perpendicular to the extension direction DE.

The first lid part32is coupled to an end part on one side (+DE side) in the extension direction DE in the circulation part31. The first lid part32has a rectangular solid box-like shape elongated in the rotational axis direction DR. Inside the first lid part32, one ends in the extension direction DE of the pipe parts31aopen. As shown inFIG. 3, inside the first lid part32, there is disposed a partition part32a. The partition part32aseparates the inside of the first lid part32into a first space S1and a second space S2arranged side by side in the rotational axis direction DR. InFIG. 3, the first space S1is located on the right side (+DR side) of the second space S2.

The first lid part32is provided with a communication hole32bfor communicating the first space S1and the inside of the circulation duct26with each other. The first lid part32is provided with a communication hole32cfor communicating the second space S2and the inside of the circulation duct25with each other.

The second lid part33is coupled to an end part on the other side (−DE side) in the extension direction DE in the circulation part31, namely an end part on an opposite side to the side where the first lid part32is coupled to the circulation part31. As shown inFIG. 5, the second lid part33has a rectangular solid box-like shape elongated in the rotational axis direction DR. Inside the second lid part33, the other ends in the extension direction DE of the pipe parts31aopen. Unlike the first lid part32, the inside of the second lid part33is not partitioned. The inside of the second lid part33is communicated with each of the first space S1and the second space S2of the first lid part32via the inside of each of the pipe parts31aof the circulation part31. The second lid part33is coupled to the refrigerant sender50. Thus, the heat exchanger30is coupled to the refrigerant sender50. It should be noted that inFIG. 5, a wall on the other side in the extension direction DE in the second lid part33is omitted.

As shown inFIG. 3, the circulation duct26is a duct disposed on one side (+DR side) of the moisture absorption/desorption member40in the rotational axis direction DR. The circulation duct26has an inflow port opening on the other side (−DR side) in the rotational axis direction DR toward a part of the moisture absorption/desorption member40located in the second area F2. The circulation duct26has an outflow port to be communicated with the communication hole32bof the first lid part32.

The circulation duct25is a duct disposed on the other side (−DR side) of the moisture absorption/desorption member40in the rotational axis direction DR. The circulation duct25has an outflow port opening on the one side (+DR side) in the rotational axis direction DR toward the part of the moisture absorption/desorption member40located in the second area F2. The circulation duct25has an inflow port to be communicated with the communication hole32cof the first lid part32.

The heater22has a heating main body part22a. The heating main body part22ais disposed inside the circulation duct25. The heating main body part22ais disposed on the other side (−DR side) of the part of the moisture absorption/desorption member40located in the second area F2in the rotational axis direction DR. The heating main body part22ais, for example, an electric heater. The heating main body part22aheats an inside atmosphere (air) of the circulation duct25. In the present embodiment, the heater22has the second blower23.

The second blower23is disposed inside the circulation duct26. The second blower23is disposed on the one side (+DR side) of the part of the moisture absorption/desorption member40located in the second area F2in the rotational axis direction DR. The second blower23is, for example, a centrifugal fan. The air taken from the other side (−DR side) in the rotational axis direction DR is discharged by the second blower23toward the other side (−DE side) in the extension direction DE from an exhaust port23a. The exhaust port23aopens in the communication hole32bof the first lid part32. The second blower23feeds the air to the first space S1via the communication hole32b.

The air discharged from the second blower23to the first space S1is the air having been taken in from the other side (−DR side) in the rotational axis direction DR of the second blower23via the inflow port of the circulation duct26, and is the air having passed through the part of the moisture absorption/desorption member40located in the second area F2. In other words, the second blower23makes the air pass through the part of the moisture absorption/desorption member40located in the second area F2different from the first area F1, and then feeds the air to the heat exchanger30. In the present embodiment, the air which has not passed the part of the moisture absorption/desorption member40located in the second area F2flows inside the circulation duct25. Therefore, the heating main body part22aheats the air which has not passed the part of the moisture absorption/desorption member40located in the second area F2.

As described above, in the present embodiment, the heater22feeds the air which has been heated by the heating main body part22ato the part of the moisture absorption/desorption member40located in the second area F2by the second blower23to thereby heat the part of the moisture absorption/desorption member40located in the second area F2. Thus, the second blower23feeds the ambient air of the part heated by the heater22in the moisture absorption/desorption member40to the heat exchanger30.

The air which has flowed into the heat exchanger30from the second blower23via the first space S1passes inside the pipe parts31acommunicated with the first space S1out of the plurality of pipe parts31a, and then inflows into the inside of the second lid part33. The air which has flowed into the inside of the second lid part33passes through the inside of the pipe parts31acommunicated with the second space S2out of the plurality of pipe parts31a, then inflows into the second space S2, and then inflows into the inside of the circulation duct25from the communication hole32c. The air having flowed into the inside of the circulation duct25is heated by the heating main body part22a, then passes through the part of the moisture absorption/desorption member40located in the second area F2once again, then inflows into the inside of the circulation duct26, and is then taken in by the second blower23.

As described hereinabove, in the present embodiment, the refrigerant generator20has a circulation channel27through which the air discharged from the second blower23circulates. The circulation channel27is constituted by at least the circulation ducts25,26and the heat exchanger30. The circulation channel27passes the heating main body part22a, the moisture absorption/desorption member40, and the heat exchanger30. Although a narrow gap is provided between the moisture absorption/desorption member40and each of the circulation ducts25, the circulation channel27is substantially sealed, and thus, the air from the outside is prevented from inflowing into the inside of the circulation channel27. It should be noted that in the following description, the air which has been discharged from the second blower23and then circulates through the circulation channel27is referred to as air AR2.

The cooling duct21is a duct having an inflow port disposed on the one side (+DR side) of the part of the moisture absorption/desorption member40located in the first area F1in the rotational axis direction DR. Into the cooling duct21, there inflows the air AR1which has been discharged from the first blower60, and has passed through the part of the moisture absorption/desorption member40located in the first area F1. The cooling duct21extends from an area on one side of the part of the moisture absorption/desorption member40located in the first area F1toward the heat exchanger30.

The cooling duct21has a cooling passage part21aextending in the rotational axis direction DR. In the cooling passage part21a, there is disposed the circulation part31of the heat exchanger30so as to penetrate in the extension direction DE. Thus, in the inside of the cooling passage part21a, there is disposed the circulation part31. The air AR1passing through the cooling passage part21ais made to blow against the outside surface of the circulation part31, and then passes through the circulation part31in the rotational axis direction DR. Thus, the circulation part31is cooled by the air AR1. In other words, the heat exchanger30is cooled by the air AR1which has been discharged from the first blower60, and then passed through the moisture absorption/desorption member40. InFIG. 3, the air AR1passes through the circulation part31from the right side to the left side in the cooling passage part21a. An end part on the other side (−DR side) in the rotational axis direction DR in the cooling passage part21aopens. The opening of the cooling passage part21ais, for example, an outflow port of the cooling duct21.

When the air AR1is fed to the part of the moisture absorption/desorption member40located in the first area F1from the first blower60, the steam included in the air AR1is absorbed by the part of the moisture absorption/desorption member40located in the first area F1. The part of the moisture absorption/desorption member40having absorbed the steam as the moisture moves from the first area F1to the second area F2by the motor24rotating the moisture absorption/desorption member40. Then, through the part of the moisture absorption/desorption member40located in the second area F2, there passes the air AR2which has been heated by the heating main body part22a, and is relatively high in temperature. Thus, the moisture having been absorbed by the moisture absorption/desorption member40evaporates to be released to the air AR2.

The air AR2including the steam which has been absorbed from the air AR1by passing through the moisture absorption/desorption member40is fed by the second blower23to the heat exchanger30. The air AR2having flowed into the heat exchanger30from the first space S1flows through the circulation part31. More particularly, the air AR2flows through the pipe parts31aof the circulation part31. The circulation part31is cooled from the outside by the air AR1flowing along the rotational axis direction DR through the cooling passage part21aof the cooling duct21.

When the circulation part31is cooled, the air AR2which flows through the pipe parts31aand is relatively high in temperature is cooled, and thus, the steam having been included in the air AR2is condensed to the water as a fluid, namely the refrigerant W. In such a manner, the heat exchanger30is cooled to thereby generate the refrigerant W from the air AR2having flowed into the heat exchanger30.

In the present embodiment, the refrigerant sender50is formed of a porous member, and transmits the refrigerant W due to a capillary action. As the material of the refrigerant sender50, there can be cited, for example, polypropylene, cotton, and porous metal. It is preferable for the material of the refrigerant sender50to be a material capable of making the surface tension of the refrigerant sender50relatively high. As shown inFIG. 5, the refrigerant sender50has a first trapping part51, a second trapping part52, a third trapping part53, and a coupling part54.

The first trapping part51is fixed to an edge part on the one side (+DE side) in the extension direction DE in the inside surface of the first lid part32. The first trapping part51is shaped like a thin belt, and is formed along the edge part of the first lid part32to have a rectangular frame shape. The second trapping part52is fixed to an edge part on the other side (−DE side) in the extension direction DE in the inside surface of the second lid part33. The second trapping part52is shaped like a thin belt, and is formed along the edge part of the second lid part33to have a rectangular frame shape.

The third trapping part53extends from the first trapping part51to the second trapping part52through the inside of the pipe part31ato couple the first trapping part51and the second trapping part52to each other. The third trapping part53is shaped like a thin belt extending in the extension direction DE. In the present embodiment, the third trapping part53is disposed inside one of the pipe parts31aas shown inFIG. 5, but this is not a limitation. The third trapping part53can be disposed inside some of the pipe parts31a, or can also be disposed inside all of the pipe parts31a. When the third trapping part53is disposed inside some of the pipe parts31a, it is also possible for the third trapping part53to be disposed inside two or more of the pipe parts31a.

The coupling part54is a part for coupling the refrigerant generator20and the cooling target to each other. In the present embodiment, the coupling part54is coupled to the second trapping part52, and projects from the inside of the second lid part33to the outside of the second lid part33so as to penetrate the wall of the second lid part33. As shown inFIG. 6, the coupling part54projecting to the outside of the second lid part33extends to the light modulation unit4G as the cooling target.FIG. 6is a perspective view showing the light modulation units4R,4G, and4B, and the light combining optical system5. The coupling part54is shaped like a thin belt. The width of the coupling part54is larger than, for example, the width of the first trapping part51, the width of the second trapping part52, and the width of the third trapping part53.

Then, the light modulation units4R,4G, and4B as the cooling target in the present embodiment will be described in more detail. In the following description, a vertical direction Z defining a positive side as an upper side and a negative side as a lower side is arbitrarily represented by a Z axis in the drawings. A direction parallel to an optical axis AX of a projection lens the closest to the light exit side in the projection optical device6, namely a direction parallel to the projection direction of the projection optical device6, is referred to as an “optical axis direction X,” and is arbitrarily represented by an X axis in the drawings. The optical direction X is perpendicular to the vertical direction Z. Further, a direction perpendicular to both of the optical axis direction X and the vertical direction Z is referred to as a “width direction Y,” and is arbitrarily represented by a Y axis in the drawings.

It should be noted that the vertical direction Z, the upper side, and the lower side are mere names for explaining the relative positional relationship between the constituents, and the actual arrangement relationship and so on can also be other arrangement relationships and so on than the arrangement relationships and so on represented by these names.

FIG. 7is a diagram of the light modulation unit4G viewed from a light incident side.FIG. 8is a diagram showing the light modulation unit4G, and corresponds to an VIII-VIII cross-sectional view inFIG. 7.

As shown inFIG. 6, the light modulation unit4R, the light modulation unit4G, and the light modulation unit4B as the cooling target are disposed so as to surround the light combining optical system5. The light modulation unit4R and the light modulation unit4B are disposed across the light combining optical system5from each other in the width direction Y. The light modulation unit4G is disposed on the light incident side (−X side) in the optical axis direction X of the light combining optical system5. Since the structure of the light modulation unit4R, the structure of the light modulation unit4G, and the structure of the light modulation unit4B are substantially the same as each other except the arrangement position and the arrangement posture, in the following description, the light modulation unit4G is described alone as a representative in some cases.

The light modulation unit4G has a holding frame80for holding the light modulator4GP. As shown inFIG. 6throughFIG. 8, the holding frame80is shaped like a substantially rectangular solid flat in a direction in which the light enters the light modulator4GP and elongated in the vertical direction Z. The direction in which the light enters the light modulator4GP is, for example, the optical axis direction X.

As shown inFIG. 8, the holding frame80has a through hole81penetrating the holding frame80in the incident direction of the light. On the edge on the light incident side (−X side) of the through hole81, there is disposed a step part83where the width of the through hole81increases. The light modulator4GP is fitted in the step part83and held by the holding frame80. As shown inFIG. 7, in the portions on the both sides in the vertical direction Z in the surface on the light incident side of the holding frame80, there are formed insertion grooves82a,82b.

As shown inFIG. 6throughFIG. 8, the projector1is further provided with a cooling promotion section70installed in the light modulation unit4G as the cooling target. The cooling promotion section70has a refrigerant holder71and a fixation member72. The refrigerant holder71is attached to a surface of the holding frame80of the light modulation unit4G as the cooling target. In the present embodiment, the refrigerant holder71is disposed on a surface on the light incident side (−X side) of the light modulator4GP in the holding frame80. The refrigerant holder71is formed of a porous member for retaining the refrigerant W. As the material of the refrigerant holder71, there can be cited, for example, polypropylene, cotton, and porous metal. The material of the refrigerant holder71can be made the same as the material of, for example, the refrigerant sender50. It is preferable for the material of the refrigerant holder71to be a material capable of making the surface tension of the refrigerant holder71relatively high.

FIG. 9is a diagram showing the refrigerant holder71. As shown inFIG. 9, the refrigerant holder71has a main body part71ashaped like a rectangular frame, and insertion parts71b,71cdisposed in end parts on both sides in the vertical direction Z in the main body part71a. As shown inFIG. 8, the main body part71acovers a part of the surface on the light incident side (−X side) of the light modulator4GP in the holding frame80. A portion on an inner edge side in the main body part71acovers an outer edge portion of the light modulator4GP. The insertion part71bis folded, and is inserted in the insertion groove82aof the holding frame80. The insertion part71cis folded, and is inserted in the insertion groove82bof the holding frame80.

The fixation member72is a member for fixing the refrigerant holder71. As shown inFIG. 6andFIG. 8, the fixation member72is a plate like member. The fixation member72is made of, for example, metal. The fixation member72has a frame part72ashaped like a rectangular frame, attachment parts72b, and insertion parts72c. As shown inFIG. 7andFIG. 8, the frame part72acovers an outer edge part of the refrigerant holder71. The holding frame80, the refrigerant holder71, and the frame part72aare stacked on one another in a direction (the optical axis direction X) of the light passing through the light modulation unit4G. In the following description, the direction in which the holding frame80, the refrigerant holder71, and the frame part72aare stacked on one another is simply referred to as a “stacking direction.” The fixation member72fixes the refrigerant holder71by sandwiching the refrigerant holder71between the frame part72aand the holding frame80in the stacking direction (the optical axis direction X).

An inner edge of the frame part72ais disposed on the outer side of an inner edge of the refrigerant holder71. Therefore, apart of the refrigerant holder71, namely a portion on the inner side of the frame part72ain the present embodiment, is exposed when viewed from the fixation member72side in the stacking direction.

As shown inFIG. 6andFIG. 8, the attachment parts72bare respectively provided to both end parts in the width direction Y in the both end parts in the vertical direction Z of the frame part72a. The attachment parts72beach project from the frame part72atoward the holding frame80(+X side). The attachment parts72bare respectively engaged with protrusions disposed on the side surfaces of the holding frame80. Thus, the fixation member72is fixed to the holding frame80.

The insertion parts72care disposed on both end parts in the vertical direction Z of the frame part72a. The insertion parts72ceach project from the frame part72atoward the holding frame80(+X side). The insertion parts72care respectively inserted in the insertion grooves82a,82bof the holding frame80. The insertion parts72cpress the insertion parts71b,71cof the refrigerant holder71inside the insertion grooves82a,82b, respectively.

The cooling promotion section70is provided to each of the light modulation units4R,4G, and4B. In other words, the refrigerant holder71and the fixation member72are provided to each of the light modulation units4R,4G, and4B. As shown inFIG. 9, the refrigerant holder71G provided to the light modulation unit4G out of the light modulation units4R,4G, and4B is coupled to the refrigerant sender50. More particularly, a coupling part54of the refrigerant sender50is coupled to a lower end part of the refrigerant holder71G.

The refrigerant holder71B attached to the light modulation unit4B and the refrigerant holder71R attached to the light modulation unit4R are substantially the same as the refrigerant holder71G attached to the light modulation unit4G except the point that the coupling part54is not coupled thereto.

In the present embodiment, on both sides of the refrigerant holder71G attached to the light modulation unit4G, there are disposed the junction parts73a,73bto which the refrigerant holder71B attached to the light modulation unit4B and the refrigerant holder71R attached to the light modulation unit4R are respectively joined. The junction parts73a,73bare each made of a porous member.

The junction part73ajoins the refrigerant holder71G attached to the light modulation unit4G and the refrigerant holder71B attached to the light modulation unit4B to each other. Thus, the refrigerant holder71B is coupled to the coupling part54of the refrigerant sender50via the refrigerant holder71G. As shown inFIG. 6, the junction part73ais provided with a cover part74for covering the junction part73a. The cover part74is, for example, a film made of resin.

The junction part73bjoins the refrigerant holder71attached to the light modulation unit4G and the refrigerant holder71attached to the light modulation unit4R to each other. Thus, the refrigerant holder71R is coupled to the coupling part54of the refrigerant sender50via the refrigerant holder71G. Although not shown in the drawings, the junction part73bis also provided with the cover part74similarly to the junction part73a.

The refrigerant W generated by the refrigerant generator20is transmitted to the refrigerant holder71G using the coupling part54of the refrigerant sender50. The refrigerant W transmitted to the refrigerant holder71G is transmitted to the refrigerant holder71B via the junction part73a, and at the same time, transmitted to the refrigerant holder71R via the junction part73b. In such a manner, the refrigerant W generated in the refrigerant generator20is transmitted to the three light modulation units4R,4G, and4B. Then, the refrigerant W transmitted to and then retained in the refrigerant holder71is evaporated, and thus, the light modulation units4R,4G, and4B as the cooling target are cooled. More particularly, by the refrigerant W retained in the refrigerant holder71evaporating, the holding frame80attached with the refrigerant holder71is cooled, and by the holding frame80being cooled, the light modulators4RP,4GP, and4BP held by the holding frame80are cooled. Thus, it is possible to cool the light modulators4RP,4GP, and4BP as the cooling target with the cooler10.

As shown inFIG. 2, the projector1is further provided with a temperature sensor91capable of measuring the temperature of the cooling target, and a controller90for controlling the cooler10. In the present embodiment, the temperature sensor91is provided to each of the light modulation units4R,4G, and4B as the cooling target. The temperature sensors91are capable of respectively measuring the temperature of the light modulation units4R,4G, and4B as the cooling target. More particularly, the temperature sensors91are capable of respectively measuring the temperature of the light modulators4RP,4GP, and4BP. The measuring result of each of the temperature sensors91is transmitted to the controller90.

In the present embodiment, the controller90controls the refrigerant generator20based on the temperature of the cooling target. The controller90controls at least one of the output of the first blower60, the output of the heater22, and a cooling degree by the heat exchanger30based on the temperature of the light modulators4RP,4GP, and4BP obtained from the temperature sensors91. In the present embodiment, the controller90controls all of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30based on the temperature of the light modulators4RP,4GP, and4BP.

The controller90controls a voltage to be applied to the first blower60to thereby control the output of the first blower60and the cooling degree of the heat exchanger30. When the voltage to be applied to the first blower60increases, the output of the first blower60increases, and the amount of the air AR1fed by the first blower60increases. Therefore, the amount of the air AR1fed to the moisture absorption/desorption member40increases, and thus, it is possible to increase the amount of the steam absorbed as moisture by the moisture absorption/desorption member40from the air AR1. Thus, it is possible to increase the amount of the steam to be released to the air AR2from the moisture absorption/desorption member40, and thus, it is possible to increase the amount of the steam condensed in the heat exchanger30. Therefore, it is possible to increase the amount of generation of the refrigerant W in the refrigerant generator20.

Further, when the voltage to be applied to the first blower60increases, the amount of the air AR1blowing against the circulation part31from the first blower21via the cooling duct21increases. Thus, it is possible to increase the cooling degree of the heat exchanger30, and thus, it is possible to further cool the heat exchanger30. Therefore, it is possible to further condense the steam included in the air AR2fed into the circulation part31, and thus, it is possible to increase the amount of generation of the refrigerant W in the refrigerant generator20.

In contrast, when the voltage to be applied to the first blower60decreases, the output of the first blower60decreases, and the amount of the air AR1fed from the first blower60to the moisture absorption/desorption member40and the circulation part31decreases. Thus, the amount of the steam absorbed as moisture by the moisture absorption/desorption member40decreases, and at the same time, the cooling degree by the heat exchanger30decreases. Therefore, it is possible to decrease the amount of the steam condensed in the heat exchanger30, and thus, it is possible to decrease the amount of generation of the refrigerant W in the refrigerant generator20.

The controller90controls the voltage to be applied to the heating main body part22ato thereby control the output of the heater22. When the voltage to be applied to the heating main body part22aincreases, the output of the heater22increases, and it is easier to heat the moisture absorption/desorption member40by the heater22. Therefore, it is possible to increase the amount of the steam to be released from the moisture absorption/desorption member40to the air AR2. Thus, in the heat exchanger30, it is possible to condense a larger amount of steam from the air AR2. Therefore, it is possible to increase the amount of generation of the refrigerant W in the refrigerant generator20. In contrast, when the voltage to be applied to the heating main body part22adecreases, the output of the heater22decreases, and thus, the amount of the steam to be released from the moisture absorption/desorption member40to the air AR2decreases. Therefore, it is possible to decrease the amount of the steam condensed in the heat exchanger30, and thus, it is possible to decrease the amount of generation of the refrigerant W in the refrigerant generator20.

FIG. 10is a flowchart showing an example of a procedure of controlling the controller90in the present embodiment. In the present embodiment, the controller90performs cooling of the cooling target by the cooler10with a goal of keeping the temperature of the cooling target within a target temperature range along the procedure shown inFIG. 10. The target temperature range is, for example, a temperature range set in advance. The target temperature range is, for example, a temperature range of the cooling target in which the operation and the state of the cooling target can be kept in a good condition when the projector1is in operation. When the cooling target is the light modulators4RP,4GP, and4BP as in the present embodiment, the target temperature range is, for example, no higher than 40° C. and no lower than 60° C.

As shown inFIG. 10, the controller90determines (step St12) whether or not the temperature of the cooling target is within the target temperature range after the projector1has started up (step St11). In the present embodiment, the controller90determines whether or not the temperature of the light modulators4RP,4GP, and4BP is within the target temperature range based on the measuring result by the temperature sensors91. When the temperature of the cooling target is within the target temperature range (YES in the step St12), the controller90keeps (step St13) the output of the refrigerant generator20in the current output. In other words, the controller90keeps the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30in the current state without making changes.

In contrast, when the temperature of the cooling target is out of the target temperature range (NO in the step St12), the controller90determines (step St14) whether or not the temperature of the cooling target is higher than the target temperature range. In the present embodiment, the controller90determines whether or not the temperature of the light modulators4RP,4GP, and4BP is higher than the target temperature range based on the measuring result by the temperature sensors91.

It should be noted that in the present embodiment, the controller90determines that the temperature of the cooling target is out of the target temperature range when the temperature is out of the target temperature range in at least one of the three light modulators4RP,4GP, and4BP even when the temperature is within the target temperature range in the rest of the light modulators.

When the temperature of the cooling target is higher than the target temperature range (YES in the step St14), the controller90increases (step St15) the output of the refrigerant generator20. In other words, the controller90increases the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30. Specifically, the controller90raises the voltage to be applied to the first blower60and the voltage to be applied to the heating main body part22a.

The degree of increasing the output of the refrigerant generator20can be set to a predetermined value in advance, or can also be set in accordance with a difference between the temperature of the cooling target and the upper limit value of the target temperature range, for example. When setting the degree of increasing the output of the refrigerant generator20in accordance with the difference between the temperature of the cooling target and the upper limit of the target temperature range, it is possible for the controller90to set the degree of increasing the output of the refrigerant generator20so that, for example, the larger the difference between the temperature of the cooling target and the upper limit of the target temperature range is, the higher the degree of increasing the output of the refrigerant generator20is.

In the present embodiment, the degree of increasing the output of the refrigerant generator20means a voltage value raised in the voltage to be applied to the first blower60and a voltage value raised in the voltage to be applied to the heating main body part22a. The voltage value raised in the voltage to be applied to the first blower60and the voltage value raised in the voltage to be applied to the heating main body part22acan be the same as each other, or can also be different from each other.

In contrast, when the temperature of the cooling target is lower than the target temperature range (NO in the step St14), the controller90decreases (step St16) the output of the refrigerant generator20. In other words, the controller90decreases the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30. Specifically, the controller90lowers the voltage to be applied to the first blower60and the voltage to be applied to the heating main body part22a.

The degree of decreasing the output of the refrigerant generator20can be set to a predetermined value in advance, or can also be set in accordance with the difference between the temperature of the cooling target and the lower limit value of the target temperature range, for example. When setting the degree of decreasing the output of the refrigerant generator20in accordance with the difference between the temperature of the cooling target and the lower limit of the target temperature range, it is possible for the controller90to set the degree of decreasing the output of the refrigerant generator20so that, for example, the larger the difference between the temperature of the cooling target and the lower limit of the target temperature range is, the higher the degree of decreasing the output of the refrigerant generator20is.

In the present embodiment, the degree of decreasing the output of the refrigerant generator20means a voltage value lowered in the voltage to be applied to the first blower60and a voltage value lowered in the voltage to be applied to the heating main body part22a. The voltage value lowered in the voltage to be applied to the first blower60and the voltage value lowered in the voltage to be applied to the heating main body part22acan be the same as each other, or can also be different from each other.

The degree of raising the output of the refrigerant generator20in the step St15and the degree of decreasing the output of each of the sections in the step St16can be the same as each other, or can also be different from each other. In other words, the absolute value of the increment in the voltage to be applied to the first blower60in the step St15and the absolute value of the decrement in the voltage to be applied to the first blower60in the step St16can be the same as each other, or can also be different from each other. The absolute value of the increment in the voltage to be applied to the heating main body part22ain the step St15and the absolute value of the decrement in the voltage to be applied to the heating main body part22ain the step St16can be the same as each other, or can also be different from each other.

In such a manner as described above, the controller90changes at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the temperature of the light modulation units4R,4G, and4B as the cooling target is out of the target temperature range. In the present embodiment, the controller90changes all of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the temperature of the cooling target is out of the target temperature range. Further, the controller90increases at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the temperature of the cooling target is higher than the target temperature range, and further, decreases at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the temperature of the cooling target is lower than the target temperature range.

In the present embodiment, the controller90repeatedly executes the control in the step St12through the step St16described above every predetermined time during the period when the projector1is in operation. The predetermined time is, for example, several seconds.

According to the present embodiment, it is possible for the cooler10to cool the cooling target by drawing heat from the cooling target using the evaporation of the refrigerant W as an endothermic reaction after transmitting the refrigerant W generated in the refrigerant generator20to the cooling target with the refrigerant sender50. The cooling action by the evaporation of the refrigerant W can actively draw heat from the cooling target, and is therefore superior in cooling performance compared to when cooling the cooling target by mere heat transmission to the refrigerant as in the case of air cooling or liquid cooling. Thus, when obtaining the same cooling performance as those of air cooling and liquid cooling, it is easy to reduce the entire size of the cooler10compared to air cooling and liquid cooling.

Further, in the case of the cooling action by the evaporation of the refrigerant W, the cooling performance can be improved by increasing the surface area where the refrigerant W to be evaporated has contact with the cooling target. Therefore, even when raising the cooling performance obtained using the cooler10, it is possible to suppress an increase in the sound noise. As described above, according to the present embodiment, it is possible to obtain the projector1equipped with the cooler10excellent in cooling performance, small in size, and excellent in quietness.

Further, according to the present embodiment, since the refrigerant W can be generated in the refrigerant generator20, time and effort for refilling the refrigerant W are not required for the user, and thus, the convenience of the user can be enhanced. Further, since it is possible for the refrigerant generator20to control generation of the refrigerant W so as to generate necessary amount of refrigerant W when needed, it is not necessary to retain the refrigerant W in a reservoir tank or the like, and thus, it is possible to reduce the weight of the projector1.

Further, according to the present embodiment, it is possible to absorb the steam included in the air AR1fed from the first blower60by the moisture absorption/desorption member40, and it is possible to release the moisture absorbed by the moisture absorption/desorption member40in the air AR2fed by the second blower23as steam. Further, it is possible to generate the refrigerant W by condensing the moisture released as steam in the air AR2using the heat exchanger30. Thus, according to the present embodiment, it is possible to generate the refrigerant W from the air in the projector1.

Further, according to the present embodiment, the heat exchanger30is cooled by the air AR1which has been discharged from the first blower60, and then passed through the moisture absorption/desorption member40. Therefore, it is unnecessary to separately dispose a cooling section for cooling the heat exchanger30, and thus, it is possible to suppress an increase in the number of components of the projector1. Further, it is possible to prevent the sound noise generated from the projector1from increasing compared to when additionally provide a blower as the cooling section for cooling the heat exchanger30.

Further, according to the present embodiment, the first blower60is the cooling blower for feeding the air AR1to the light modulation units4R,4G, and4B as the cooling target. Therefore, it is easy to evaporate the refrigerant W transmitted to the light modulation units4R,4G, and4B with the air AR1, and it is possible to further cool the light modulation units4R,4G, and4B. Further, since it is unnecessary to separately provide the cooling blower for cooling the cooling target in addition to the first blower60, it is possible to prevent the number of components of the projector1from increasing, and it is possible to prevent the sound noise from increasing.

Further, as described above, in the present embodiment, the evaporation of the refrigerant W fed to the cooling target is promoted using the first blower60as the intake fan for taking in the external air inside the projector1. Even when lowering the output of the first blower60, it is possible to obtain the cooling performance equivalent to when the cooler10is not provided. Therefore, it is possible to lower the output of the first blower60as the intake fan to thereby reduce the sound noise generated from the first blower60, and thus, it is possible to further enhance the quietness of the projector1.

Further, for example, in the refrigerant generator20, when the humidity of the air AR2fed from the second blower23to the heat exchanger30is relatively low, the refrigerant W is difficult to be generated in some cases even when the heat exchanger30is cooled. The humidity of the air AR2to be fed to the heat exchanger30drops in some cases when, for example, the air outside the projector1is mixed with the air AR2.

In this regard, according to the present embodiment, the refrigerant generator20has the circulation channel27through which the air AR2discharged from the second blower23circulates. Therefore, it is possible to prevent the air located outside the projector1from entering the circulation channel27by substantially sealing the circulation channel27, and it is easy to keep the humidity of the air AR2fed to the heat exchanger30in a relatively high state. Therefore, by cooling the heat exchanger30, it is possible to generate the refrigerant W in good condition.

Further, according to the present embodiment, the heater22has the heating main body part22afor heating the air which has not passed the part of the moisture absorption/desorption member40located in the second area F2, and the second blower23. Therefore, it is possible for the heater22to heat the part of the moisture absorption/desorption member40located in the second area F2by feeding the air AR2to the moisture absorption/desorption member40using the second blower23. Thus, it is possible to heat the moisture absorption/desorption member40using the heater22even when disposing the heating main body part22aat a position distant from the moisture absorption/desorption member40. Therefore, the degree of freedom of the configuration of the heater22can be enhanced.

Further, for example, when the temperature of the cooling target becomes out of the target temperature range, there is a possibility that a problem occurs in the cooling target. For example, when the cooling target comprises the light modulators4RP,4GP, and4BP as in the present embodiment, when the temperature of the light modulators4RP,4GP, and4BP is higher than the target temperature range, there is a possibility that the light modulators4RP,4GP, and4BP are damaged by the heat. Further, when the temperature of the light modulators4RP,4GP, and4BP is lower than the target temperature range, there is a possibility that the response characteristics of the liquid crystal panels of the light modulators4RP,4GP, and4BP deteriorate to cause a blur, a flicker, and so on in the color image (picture) emitted from the projector1. Therefore, there is a possibility that the reliability of the projector1degrades.

In contrast, according to the present embodiment, the controller90controls the refrigerant generator20based on the temperature of the cooling target. Therefore, it is possible to control the amount of the refrigerant W to be generated in the refrigerant generator20based on the temperature of the cooling target, and it is possible to control the temperature of the cooling target to be cooled by the refrigerant W. Thus, it is easy to keep the temperature of the cooling target within the target temperature range. Therefore, it is possible to prevent the problem from occurring in the cooling target, and it is possible to prevent the reliability of the projector1from degrading.

Further, according to the present embodiment, the controller90controls at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30based on the temperature of the cooling target. Therefore, it is possible for the controller90to control at least one of an amount of the steam absorbed by the moisture absorption/desorption member40, an amount of the steam released to the air AR2from the moisture absorption/desorption member40, and an amount of the steam condensed in the heat exchanger30. Thus, by controlling the output or the like of each section of the refrigerant generator20, it is possible to easily control the amount of the refrigerant W generated in the refrigerant generator20. Therefore, it is easier to keep the temperature of the cooling target within the target temperature range, and it is possible to more strictly prevent the reliability of the projector1from degrading.

Further, according to the present embodiment, the controller90changes at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the temperature of the cooling target is out of the target temperature range. Therefore, when the temperature of the cooling target becomes out of the target temperature range, it is possible to control the amount of generation of the refrigerant W so that the temperature of the cooling target becomes within the target temperature range. Therefore, it is easier to keep the temperature of the cooling target within the target temperature range, and it is possible to more strictly prevent the reliability of the projector1from degrading.

More particularly, in the present embodiment, the controller90increases at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the temperature of the cooling target is higher than the target temperature range. Therefore, when the temperature of the cooling target becomes higher than the target temperature range, it is possible to increase the amount of generation of the refrigerant W, and it is possible to increase the cooling degree by the cooling target. Thus, it is possible to lower the temperature of the cooling target, and thus, it is possible to set the temperature of the cooling target within the target temperature range.

Further, in the present embodiment, the controller90decreases at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the temperature of the cooling target is lower than the target temperature range. Therefore, when the temperature of the cooling target becomes lower than the target temperature range, it is possible to decrease the amount of generation of the refrigerant W, and it is possible to decrease the cooling degree by the cooling target. Thus, it is possible to raise the temperature of the cooling target, and thus, it is possible to set the temperature of the cooling target within the target temperature range.

Further, according to the present embodiment, the controller90controls all of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30based on the temperature of the cooling target. Therefore, the amount of the refrigerant W generated in the refrigerant generator20can more easily be controlled. Thus, it is possible to more easily control the temperature of the cooling target, and it is easy to more preferably keep the temperature of the cooling target within the target temperature range. Therefore, it is possible to more strictly prevent the reliability of the projector1from degrading.

Further, according to the present embodiment, the cooling target corresponds to the light modulators4RP,4GP, and4BP. Therefore, by controlling the refrigerant generator20based on the temperature of the light modulators4RP,4GP, and4BP, it is easy to keep the temperature of the light modulators4RP,4GP, and4BP within the target temperature range. Thus, it is possible to prevent the blur and the flicker from occurring in the color image (picture) emitted from the projector1.

Further, according to the present embodiment, the refrigerant generator20has the motor24for rotating the moisture absorption/desorption member40. Therefore, it is possible to stably rotate the moisture absorption/desorption member40at a constant speed. Thus, it is possible to make the part of the moisture absorption/desorption member40located in the first area F1preferably absorb the steam from the air AR1, and at the same time, it is possible to make the part of the moisture absorption/desorption member40located in the second area F2preferably release the moisture to the air AR2. Therefore, it is possible to efficiently generate the refrigerant W.

Further, according to the present embodiment, the refrigerant sender50transmits the refrigerant W due to a capillary action. Therefore, there is no need to separately prepare a power source such as a pump for transmitting the refrigerant W. Thus, it is possible to prevent the number of components of the projector1from increasing, and thus, it is easier to reduce the size and the weight of the projector1.

Further, according to the present embodiment, the refrigerant sender50has the coupling part54made of the porous material for coupling the refrigerant generator20and the cooling target to each other. Therefore, it is possible to make the coupling part54absorb the refrigerant W to transmit the refrigerant W with the capillary action.

Further, according to the present embodiment, the refrigerant sender50has the second trapping part52disposed inside the second lid part33. The second trapping part52is coupled to the coupling part54. Therefore, it is possible to absorb the refrigerant W retained inside the second lid part33using the second trapping part52to transmit the refrigerant W to the coupling part54using the capillary action. Thus, it is easy to transmit the refrigerant W thus generated to the cooling target without a waste.

Further, according to the present embodiment, the refrigerant sender50has the first trapping part51disposed inside the first lid part32, and a third trapping part53for coupling the first trapping part51and the second trapping part52to each other. Thus, it is possible to absorb the refrigerant W retained inside the first lid part32using the first trapping part51to transmit the refrigerant W to the second trapping part52via the third trapping part53using the capillary action. Therefore, it is possible to transmit the refrigerant W retained inside the first lid part32from the second trapping part52to the coupling part54to transmit the refrigerant W to the cooling target. Therefore, it is easy to transmit the refrigerant W thus generated to the cooling target with a fewer waste.

Further, according to the present embodiment, the third trapping part53passes through the pipe part31a. Therefore, it is possible to absorb the refrigerant W retained inside the pipe part31ausing the third trapping part53to transmit the refrigerant W to the cooling target via the second trapping part52and the coupling part54. Therefore, it is easy to transmit the refrigerant W thus generated to the cooling target with a fewer waste.

Further, according to the present embodiment, the width of the coupling part54is larger than, for example, the width of the first trapping part51, the width of the second trapping part52, and the width of the third trapping part53. Therefore, it is easy to make the width of the coupling part54relatively large, and it is possible to increase the amount of the refrigerant W which can be transmitted by the coupling part54. Therefore, it is easy to transmit the refrigerant W to the cooling target using the refrigerant sender50, and it is easier to cool the cooling target.

Further, on the other hand, it is easy to make the width of the first trapping part51, the width of the second trapping part52, and the width of the third trapping part53relatively small. Therefore, it is possible to reduce the amount of the refrigerant W to be retained by the first trapping part51, the second trapping part52, and the third trapping part53. Thus, it is possible to reduce the amount of the refrigerant W remaining inside the heat exchanger30while being retained in the first trapping part51, the second trapping part52, and the third trapping part53, and it is easy to transmit the refrigerant W thus generated to the cooling target with a fewer waste.

Further, according to the present embodiment, there are provided the refrigerant holders71which are respectively provided to the light modulation units4R,4G, and4B as the cooling target, and retain the refrigerant W. Therefore, the refrigerant W transmitted to the light modulation units4R,4G, and4B can be retained in the light modulation units4R,4G, and4B by the refrigerant holders71until the refrigerant W evaporates. Thus, it is easy to use the refrigerant W thus generated without a waste, and it is possible to further improve the cooling performance of the cooler10.

Further, according to the present embodiment, the refrigerant holders71are respectively attached to the surfaces of the light modulation units4R,4G, and4B as the cooling target, and are made of the porous material. Further, at least a part of each of the refrigerant holders71is exposed when viewed from the refrigerant holder71side in the stacking direction. Therefore, it is easy to evaporate the refrigerant W from the exposed part of the refrigerant holder71, and it is possible to further improve the cooling performance of the cooler10. Further, since the refrigerant holders71are each made of the porous material, it is easy to make the refrigerant W evenly take over the surface of the cooling target on which the refrigerant holder71is disposed due to the capillary action, and it is easier to cool the cooling target.

Further, for example, when fixing the refrigerant holders71to the holding frames80with an adhesive, the adhesive is absorbed by the refrigerant holders71to block the holes of the refrigerant holders71made of the porous material in some cases. Therefore, it becomes difficult for the refrigerant W to be absorbed by the refrigerant holders71, and it becomes difficult for the refrigerant holders71to retain the refrigerant W in some cases.

In contrast, according to the present embodiment, there are provided the fixation members72each for sandwiching the refrigerant holder71with the holding frame80to fix the refrigerant holder71. Therefore, it is possible to fix the refrigerant holders71to the respective holding frames80without using the adhesive. Thus, it is possible to prevent the refrigerant holders71from becoming difficult to retain the refrigerant W. Further, in the present embodiment, the fixation members72are made of metal. Therefore, the fixation members72are relatively high in thermal conductivity, and are easy to cool. Therefore, it is easy for the temperature of the fixation members72to drop due to the air AR1from the first blower60and the evaporation of the refrigerant W, and thus, it is easier to cool the cooling target having contact with the fixation members72.

Further, according to the present embodiment, the refrigerant holder71is disposed on the surface on the light incident side of the light modulator4GP in the holding frame80. Therefore, it is possible to prevent the steam as the refrigerant W evaporated from the refrigerant holder71from affecting the light emitted from the light modulator4GP to the light combining optical system5. Thus, it is possible to prevent the noise from occurring in the image projected from the projector1.

Further according to the present embodiment, the refrigerant holders71are provided to the respective light modulation units4R,4G, and4B thus disposed as the plurality of units, and there are provided the junction parts73a,73bfor joining the refrigerant holders71to each other. Therefore, by coupling the refrigerant sender50to one of the refrigerant holders71, it is possible to transmit the refrigerant W also to the rest of the refrigerant holders71. Thus, it is possible to simplify the arrangement of the refrigerant sender50inside the projector1.

Further, according to the present embodiment, the junction parts73a,73bare provided with the covering parts74for respectively covering the junction parts73a,73b. Therefore, it is possible to prevent the refrigerant W moving along the junction parts73a,73bfrom evaporating in the junction parts73a,73b. Thus, it is possible to prevent the refrigerant W from evaporating without making a contribution to cooling of the light modulation units4R,4G, and4B as the cooling target, and thus, it is possible to prevent the refrigerant W thus generated from being wasted.

It should be noted that in the present embodiment, the coupling part54can be coated similarly to the junction parts73a,73b. According to this configuration, it is possible to prevent the refrigerant W from evaporating during the transmission to the cooling target. Therefore, it is possible to efficiently transmit the refrigerant W to the cooling target, and at the same time, it is possible to more strictly prevent the refrigerant W thus generated from being wasted. It is also possible for the coupling part54and the junction parts73a,73bto be coated in the periphery with, for example, a tube. Further, it is also possible for the coupling part54and the junction parts73a,73bto be provided with a coating treatment for preventing the evaporation on the respective surfaces.

Second Embodiment

The present embodiment is different from the first embodiment in the control procedure by the controller90, and in the point that a humidity sensor192represented by the dashed-two dotted lines inFIG. 2is provided. The rest of the configuration in the present embodiment is substantially the same as the rest of the configuration in the first embodiment. It should be noted that the constituents substantially the same as those of the embodiment described above are arbitrarily denoted by the same reference symbols, and the description thereof will be omitted in some cases.

The humidity sensor192is provided to, for example, the housing of the projector1. The humidity sensor192is capable of measuring the ambient humidity of the projector1, namely the humidity in the external environment in which the projector1is installed. The measuring result of the humidity sensor192is transmitted to the controller90.

In the present embodiment, the controller90controls the refrigerant generator20based on the ambient humidity of the projector1obtained from the humidity sensor192. In the present embodiment, the controller90controls at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30based on the ambient humidity of the projector1. In the present embodiment, the controller90controls all of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30based on the ambient humidity of the projector1. The method of controlling the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30is substantially the same as in the first embodiment.

FIG. 11is a flowchart showing an example of the procedure of controlling the controller90in the present embodiment.

As shown inFIG. 11, the controller90determines (step St22) whether or not the ambient humidity of the projector1is within a preset humidity range after the projector1has started up (step St21). In the present embodiment, the controller90determines whether or not the ambient humidity of the projector1is within the preset humidity range based on the measuring result by the humidity sensor192.

The preset humidity range is, for example, a humidity range set in advance. The preset humidity range is decided based on, for example, average humidity in the place where the projector1is used. The preset humidity range is, for example, no lower than 40%, and no higher than 60%. In the present embodiment, the output of the refrigerant generator20is set so that the refrigerant W can efficiently be generated in the preset humidity range. It should be noted that the preset humidity range can arbitrarily be changed in accordance with a change of the seasons and a change in the external environment in which the projector1is installed.

When the ambient humidity of the projector1is within the preset humidity range (YES in the step St22), the controller90keeps (step St23) the output of the refrigerant generator20in the current output. In other words, the controller90keeps the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30in the current state without making changes.

In contrast, when the ambient humidity of the projector1is out of the preset humidity range (NO in the step St22), the controller90determines (step St24) whether or not the ambient humidity of the projector1is higher than the preset humidity range. In the present embodiment, the controller90determines whether or not the ambient humidity of the projector1is higher than the preset humidity range based on the measuring result by the humidity sensor192.

When the ambient humidity of the projector1is higher than the preset humidity range (YES in the step St24), the controller90sets (step St25) the refrigerant generator20to a low-output mode. The low-output mode is a mode in which the output of the refrigerant generator20becomes lower than the output of the refrigerant generator20when the humidity of the projector1is within the preset humidity range. In other words, when the ambient humidity of the projector1is higher than the preset humidity range, the controller90makes the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30lower than the levels set when the ambient humidity of the projector1is within the preset humidity range.

The output of the refrigerant generator20in the low-output mode can be, for example, a constant value, or can also be changed in accordance with the level of the ambient humidity of the projector1. When the output of the refrigerant generator20in the low-output mode changes in accordance with the level of the ambient humidity of the projector1, the controller90sets the output of the refrigerant generator20so that the higher the ambient humidity of the projector1is, the lower the output of the refrigerant generator20is. In this case, the change in output of the refrigerant generator can change linearly with respect to the ambient humidity of the projector1, or can also change in a stepwise fashion.

In contrast, when the ambient humidity of the projector1is lower than the preset humidity range (NO in the step St24), the controller90sets (step St26) the refrigerant generator20to a high-output mode. The high-output mode is a mode in which the output of the refrigerant generator20becomes higher than the output of the refrigerant generator20when the humidity of the projector1is within the preset humidity range. In other words, when the ambient humidity of the projector1is lower than the preset humidity range, the controller90makes the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30higher than the levels set when the ambient humidity of the projector1is within the preset humidity range.

The output of the refrigerant generator20in the high-output mode can be, for example, a constant value, or can also be changed in accordance with the level of the ambient humidity of the projector1. When the output of the refrigerant generator20in the high-output mode changes in accordance with the level of the ambient humidity of the projector1, the controller90sets the output of the refrigerant generator20so that the lower the ambient humidity of the projector1is, the higher the output of the refrigerant generator20is. In this case, the change in output of the refrigerant generator can change linearly with respect to the ambient humidity of the projector1, or can also change in a stepwise fashion.

In such a manner as described above, the controller90changes at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the ambient humidity of the projector1is out of the preset humidity range. In the present embodiment, the controller90changes all of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the ambient humidity of the projector1is out of the preset humidity range. Further, the controller90decreases at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the ambient humidity of the projector1is higher than the preset humidity range, and further, increases at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the ambient humidity of the projector1is lower than the preset humidity range.

In the present embodiment, the controller90repeatedly executes the control in the step St22through the step St26described above every predetermined time during the period when the projector1is in operation. The predetermined time is, for example, several seconds. The intervals (the predetermined time) of executing the control in the present embodiment can be the same as, or can also be different from, the intervals (the predetermined time) of executing the control in the first embodiment.

For example, when the ambient humidity of the projector1is higher than the preset humidity range, the amount of the steam included in the air AR1taken in from the outside of the projector1by the first blower60becomes larger than when the ambient humidity of the projector1is within the preset humidity range. Therefore, the amount of the steam absorbed by the moisture absorption/desorption member40from the air AR1increases, and as a result, the amount of generation of the refrigerant W in the refrigerant generator20increases. Therefore, there is a possibility that a larger amount of the refrigerant W than necessary is transmitted to the cooling target, and the temperature of the cooling target becomes lower than the target temperature range. Further, there is also a possibility that the refrigerant W is excessively generated, and the refrigerant W is leaked outside the projector1.

Further, for example, when the ambient humidity of the projector1is lower than the preset humidity range, the amount of the steam included in the air AR1taken in from the outside of the projector1by the first blower60becomes smaller. Therefore, the amount of the steam absorbed by the moisture absorption/desorption member40from the air AR1decreases, and as a result, the amount of generation of the refrigerant W in the refrigerant generator20decreases. Therefore, there is a possibility that a necessary amount of the refrigerant W is not transmitted to the cooling target, and the temperature of the cooling target becomes higher than the target temperature range.

In contrast, according to the present embodiment, the controller90controls the refrigerant generator20based on the ambient humidity of the projector1. Therefore, it is possible to control the amount of the refrigerant W to be generated in the refrigerant generator20based on the ambient humidity of the projector1. Thus, it is possible to generate a preferable amount of refrigerant W even when the ambient humidity of the projector1is out of the preset humidity range, and it is easy to keep the temperature of the cooling target within the target temperature range. Therefore, it is possible to prevent the problem from occurring in the cooling target, and it is possible to prevent the reliability of the projector1from degrading. Further, it is possible to prevent the refrigerant W from being leaked outside the projector1.

Further, according to the present embodiment, the controller90controls at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30based on the ambient humidity of the projector1. Therefore, similarly to the first embodiment, by controlling the output or the like of each section of the refrigerant generator20, it is possible to easily control the amount of the refrigerant W generated in the refrigerant generator20. Therefore, it is easier to keep the temperature of the cooling target within the target temperature range, and it is possible to more strictly prevent the reliability of the projector1from degrading.

Further, according to the present embodiment, the controller90changes at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the ambient humidity of the projector1is out of the preset humidity range. Therefore, when the ambient humidity of the projector1is out of the preset humidity range, it is possible to control the amount of generation of the refrigerant W so that the temperature of the cooling target becomes within the target temperature range. Therefore, it is easier to keep the temperature of the cooling target within the target temperature range, and it is possible to more strictly prevent the reliability of the projector1from degrading.

More particularly, in the present embodiment, the controller90decreases at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the ambient humidity of the projector1is higher than the preset humidity range. Therefore, when the ambient humidity of the projector1is higher than the preset humidity range, it is possible to reduce the amount of generation of the refrigerant W, and thus, it is possible to prevent the cooling degree of the cooling target from becoming higher than necessary. Thus, it is possible to prevent the temperature of the cooling target from becoming lower than the target temperature range, and thus, it is possible to set the temperature of the cooling target within the target temperature range.

Further, according to the present embodiment, the controller90increases at least one of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30when the ambient humidity of the projector1is lower than the preset humidity range. Therefore, when the ambient humidity of the projector1is lower than the preset humidity range, it is possible to increase the amount of generation of the refrigerant W, and thus, it is possible to prevent the cooling degree of the cooling target from becoming insufficient. Thus, it is possible to prevent the temperature of the cooling target from becoming higher than the target temperature range, and thus, it is possible to set the temperature of the cooling target within the target temperature range.

Further, according to the present embodiment, the controller90controls all of the output of the first blower60, the output of the heater22, and the cooling degree by the heat exchanger30based on the ambient humidity of the projector1. Therefore, the amount of the refrigerant W generated in the refrigerant generator20can more easily be controlled. Thus, it is easier to keep the temperature of the cooling target within the target temperature range. Therefore, it is possible to more strictly prevent the reliability of the projector1from degrading.

It should be noted that in the present embodiment, it is also possible to adopt the configurations and methods described below.

It is sufficient for the controller to control the refrigerant generator based on at least one of the temperature of the cooling target and the ambient humidity of the projector. In other words, it is possible for the controller to control the refrigerant generator based on both of the temperature of the cooling target and the ambient humidity of the projector. In this case, the amount of the refrigerant W generated in the refrigerant generator can more preferably be controlled. Therefore, it is possible to more preferably keep the temperature of the cooling target within the target temperature range, and it is possible to more strictly prevent the reliability of the projector from degrading.

When controlling the refrigerant generator based on both of the temperature of the cooling target and the ambient humidity of the projector, it is possible for the controller to give priority to the control of the refrigerant generator based on the temperature of the cooling target over the control of the refrigerant generator based on the ambient humidity of the projector. In this case, when the change in the output of the refrigerant generator based on the temperature of the cooling target and the change in the output of the refrigerant generator based on the ambient humidity of the projector are opposite in direction to each other, the controller executes only the change in the output of the refrigerant generator based on the temperature of the cooling target, but does not execute the change in the output of the refrigerant generator based on the ambient humidity of the projector. Thus, it is possible to make it easier to more preferably keep the temperature of the cooling target within the target temperature range.

It is sufficient for the controller to control at least one of the output of the first blower, the output of the heater, and the cooling degree by the heat exchanger when controlling the refrigerant generator. In other words, it is possible for the controller to control any one or two of the output of the first blower, the output of the heater, and the cooling degree by the heat exchanger when controlling the refrigerant generator. It is possible for the heat exchanger to be cooled by the air fed from a blower different from the first blower. In this case, it is possible to control the output of the first blower and the cooling degree by the heat exchanger separately from each other.

The heater is not limited to the embodiments described above. The heater can have a configuration of having contact with the moisture absorption/desorption member to heat the moisture absorption/desorption member. In this case, the heater is not required to heat the air which has not passed through the moisture absorption/desorption member.

In the embodiments described above, it is assumed that the cooling blower is the first blower60provided to the refrigerant generator20, but this is not a limitation. The refrigerant blower can also be separately provided in addition to the blowers provided to the refrigerant generator20.

The configuration of the cooler is not limited to the configuration in each of the embodiments described above. The cooler is not particularly limited providing the cooler includes the refrigerant generator and the refrigerant sender. The refrigerant generator can have a configuration of, for example, condensing the steam on the heat absorption surface of a Peltier element to thereby generate the refrigerant. In this case, it is possible for the controller to control the power applied to the Peltier element to thereby control the refrigerant generator.

Further, in each of the embodiments described above, it is assumed that the cooling target is the light modulation units, but this is not a limitation. The cooling target can include at least one of the light modulator, the light modulation units, the light source device, a wavelength conversion element for converting the wavelength of the light emitted from the light source device, a diffusion element for diffusing the light emitted from the light source device, and a polarization conversion element for converting the polarization direction of the light emitted from the light source device. According to this configuration, it is possible to cool each of the constituents of the projector in a similar manner as described above.

Further, although in the embodiments described above, there is described the example when the present disclosure is applied to the transmissive projector, the present disclosure can also be applied to reflective projectors. Here, “transmissive” denotes that the light modulator including the liquid crystal panel and so on is a type of transmitting the light. Further, “reflective” denotes that the light modulator is a type of reflecting the light. It should be noted that the light modulator is not limited to the liquid crystal panel or the like, but can also be a light modulator using, for example, micro-mirrors.

Further, although in the embodiments described above, there is cited the example of the projector using the three light modulators, the present disclosure can also be applied to a projector using one light modulator alone or a projector using four or more light modulators.

Further, the configurations or the methods described in the present specification can arbitrarily be combined with each other within a range in which the configurations or the methods do not conflict with each other.