U.S. patent application number 16/925526 was filed with the patent office on 2021-01-14 for projector.
This patent application is currently assigned to SEIKO EPSON CORPORATION. The applicant listed for this patent is SEIKO EPSON CORPORATION. Invention is credited to Naoya OKADA, Nobuo SUGIYAMA.
Application Number | 20210011362 16/925526 |
Document ID | / |
Family ID | 1000005300452 |
Filed Date | 2021-01-14 |
United States Patent
Application |
20210011362 |
Kind Code |
A1 |
OKADA; Naoya ; et
al. |
January 14, 2021 |
PROJECTOR
Abstract
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.
Inventors: |
OKADA; Naoya; (Shiojiri-shi,
JP) ; SUGIYAMA; Nobuo; (Azumino-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SEIKO EPSON CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
SEIKO EPSON CORPORATION
Tokyo
JP
|
Family ID: |
1000005300452 |
Appl. No.: |
16/925526 |
Filed: |
July 10, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G03B 21/16 20130101 |
International
Class: |
G03B 21/16 20060101
G03B021/16 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 12, 2019 |
JP |
2019-130443 |
Claims
1. A projector having a cooling target, comprising: 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, wherein 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, and the controller
controls the refrigerant generator based on at least one of
temperature of the cooling target and ambient humidity of the
projector.
2. The projector according to claim 1, wherein the refrigerant
generator includes a rotating moisture absorption/desorption
member, a first blower configured to deliver air to a first 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, and 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.
3. The projector according to claim 2, wherein 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.
4. The projector according to claim 3, wherein 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.
5. The projector according to claim 3, wherein 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.
6. The projector according to claim 2, wherein 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.
7. The projector according to claim 2, wherein 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.
8. The projector according to claim 7, wherein 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.
9. The projector according to claim 7, wherein 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.
10. The projector according to claim 2, wherein 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.
11. The projector according to claim 1, wherein the controller
controls the refrigerant generator based on both of the temperature
of the cooling target and the ambient humidity of the
projector.
12. The projector according to claim 11, wherein 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.
13. The projector according to claim 1, wherein the cooling target
is the light modulator.
Description
[0001] 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
[0002] The present disclosure relates to a projector.
2. Related Art
[0003] 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.
[0004] 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
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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.
[0017] The projector may be configured such that the cooling target
is the light modulator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic configuration diagram showing a
projector according to a first embodiment.
[0019] FIG. 2 is a schematic diagram showing a part of the
projector according to the first embodiment.
[0020] FIG. 3 is a schematic configuration diagram schematically
showing a refrigerant generator in the first embodiment.
[0021] FIG. 4 is a perspective view showing a moisture
absorption/desorption member in the first embodiment.
[0022] FIG. 5 is a partial cross-sectional perspective view showing
a heat exchanger in the first embodiment.
[0023] FIG. 6 is a perspective view showing light modulation units
and a light combining optical system in the first embodiment.
[0024] FIG. 7 is a diagram of the light modulation unit in the
first embodiment viewed from a light incident side.
[0025] FIG. 8 is a diagram showing the light modulation unit in the
first embodiment, and is a VIII-VIII cross-sectional view in FIG.
7.
[0026] FIG. 9 is a diagram showing a refrigerant holder in the
first embodiment.
[0027] FIG. 10 is a flowchart showing an example of a procedure of
controlling a controller in the first embodiment.
[0028] FIG. 11 is a flowchart showing an example of a procedure of
controlling a controller in a second embodiment.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0029] 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
[0030] FIG. 1 is a schematic configuration diagram showing the
projector 1 according to the present embodiment. FIG. 2 is a
schematic diagram showing a part of the projector 1 according to
the present embodiment. As shown in FIG. 1, the projector 1 is
provided with a light source device 2, a color separation optical
system 3, a light modulation unit 4R, alight modulation unit 4G, a
light modulation unit 4B, a light combining optical system 5, and a
projection optical device 6. The light modulation unit 4R has a
light modulator 4RP. The light modulation unit 4G has a light
modulator 4GP. The light modulation unit 4B has a light modulator
4BP.
[0031] The light source device 2 emits illumination light WL
regulated so as to have a substantially homogenous illuminance
distribution toward the color separation optical system 3. The
light source device 2 has, for example, a semiconductor laser as a
light source. The color separation optical system 3 separates the
illumination light WL from the light source device 2 into red light
LR, green light LG, and blue light LB. The color separation optical
system 3 is provided with a first dichroic mirror 7a, a second
dichroic mirror 7b, a first reflecting mirror 8a, a second
reflecting mirror 8b, a third reflecting mirror 8c, and a relay
lens 8d.
[0032] The first dichroic mirror 7a separates the illumination
light WL having been emitted from the light source device 2 into
the red light LR, and the light including the green light LG and
the blue light LB mixed with each other. The first dichroic mirror
7a has a property of transmitting the red light LR, while
reflecting the green light LG and the blue light LB. The second
dichroic mirror 7b separates 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 mirror 7b has a property
of reflecting the green light LG, while transmitting the blue light
LB.
[0033] The first reflecting mirror 8a is disposed in the light path
of the red light LR, and the red light LR having been transmitted
through the first dichroic mirror 7a is reflected by the first
reflecting mirror 8a toward the light modulator 4RP. The second
reflecting mirror 8b and the third reflecting mirror 8c are
disposed in the light path of the blue light LB, and the blue light
LB having been transmitted through the second dichroic mirror 7b is
guided by the second reflecting mirror 8b and the third reflecting
mirror 8c to the light modulator 4BP.
[0034] The light modulator 4RP, the light modulator 4GP, and the
light modulator 4BP are each formed of a liquid crystal panel. The
light modulator 4RP modulates the red light LR out of the light
emitted from the light source device 2 in accordance with an image
signal. The light modulator 4GP modulates the green light LG out of
the light emitted from the light source device 2 in accordance with
an image signal. The light modulator 4BP modulates the red light LB
out of the light emitted from the light source device 2 in
accordance with an image signal. Thus, the light modulators 4RP,
4GP, and 4BP 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 modulators 4RP,
4GP, and 4BP, there are respectively disposed polarization
plates.
[0035] On the light incident side of the light modulator 4RP, there
is disposed a field lens 9R for collimating the red light LR
entering the light modulator 4RP. On the light incident side of the
light modulator 4GP, there is disposed a field lens 9G for
collimating the green light LG entering the light modulator 4GP. On
the light incident side of the light modulator 4BP, there is
disposed a field lens 9B for collimating the blue light LB entering
the light modulator 4BP.
[0036] The color combining optical system 5 is formed of across
dichroic prism having a substantially cubic shape. The light
combining optical system 5 combines the image light of the
respective colors from the light modulators 4RP, 4GP, and 4BP with
each other. The light combining optical system 5 emits the image
light thus combined toward the projection optical device 6. The
projection optical device 6 is formed of a projection lens group.
The projection optical device 6 projects the image light combined
by the light combining optical system 5, namely the light modulated
by the light modulators 4RP, 4GP, and 4BP, toward a screen SCR in
an enlarged manner. Thus, a color image (picture) thus enlarged is
displayed on the screen SCR.
[0037] As shown in FIG. 2, the projector 1 is further provided with
a cooler 10. The cooler 10 cools a cooling target provided to the
projector 1 by 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 units 4R, 4G, and 4B. In other words, in the
present embodiment, the cooling target includes the light
modulators 4RP, 4GP, and 4BP.
[0038] The cooler 10 has a refrigerant generator 20 and a
refrigerant sender 50. The refrigerant generator 20 is a section
for generating the refrigerant W. The refrigerant sender 50 is 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 sender 50 to the cooling
target, namely the light modulation units 4R, 4G, and 4B in the
present embodiment, it is possible to draw the heat from the
cooling target, and thus, it is possible for the cooler 10 to cool
the cooling target. Each of the sections will hereinafter be
described in detail.
[0039] FIG. 3 is a schematic configuration diagram schematically
showing a refrigerant generator 20 in the present embodiment. As
shown in FIG. 3, the refrigerant generator 20 has a moisture
absorption/desorption member 40, a motor (a driver) 24, a first
blower (a cooling blower) 60, a heat exchanger 30, a circulation
duct 25, a circulation duct 26, a heater 22, a second blower 23, a
cooling duct 21.
[0040] FIG. 4 is a perspective view showing the moisture
absorption/desorption member 40. As shown in FIG. 4, the moisture
absorption/desorption member 40 has a flat cylindrical shape
centered on a rotational axis R. Ina central part of the moisture
absorption/desorption member 40, there is formed a central hole 40c
centered on the rotational axis R. The central hole 40c penetrates
the moisture absorption/desorption member 40 in an axial direction
of the rotational axis R. The moisture absorption/desorption member
40 rotates 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.
[0041] The moisture absorption/desorption member 40 has an
infinitely large number of through holes 40b penetrating the
moisture absorption/desorption member 40b in the rotational axis
direction DR. The moisture absorption/desorption member 40 is a
porous member. The moisture absorption/desorption member 40 has a
moisture absorption/desorption property. In the present embodiment,
the moisture absorption/desorption member 40 is manufactured by,
for example, winding a belt-like member 40a shaped like a belt and
having the through holes 40b around the rotational axis R, and then
coating a surface exposed outside in the belt-like member 40a thus
wound with a material having a moisture absorption/desorption
property. It should be noted that the surface exposed outside in
the belt-like member 40a thus wound includes an outside surface of
the moisture absorption/desorption member 40, an inner
circumferential surface of the central hole 40c, and internal
surfaces of the through holes 40b. It should be noted that the
moisture absorption/desorption member 40 can 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.
[0042] An output shaft of the motor 24 shown in FIG. 3 is fixed in
a state of being inserted into the central hole 40c of the moisture
absorption/desorption member 40. The motor 24 rotates the moisture
absorption/desorption member 40 around the rotational axis R. The
rotational speed of the moisture absorption/desorption member 40
rotated by the motor 24 is, for example, about no lower than 0.2
rpm and no higher than 5 rpm.
[0043] The first blower 60 is, for example, an intake fan for
taking external air in the projector 1. The first blower 60 feeds
air AR1 to apart of the moisture absorption/desorption member 40
located in a first area F1. The first area F1 is 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 F1
with respect to the rotational axis R, corresponds to a second area
F2. The first area F1 is an area on the upper side of the
rotational axis R in FIG. 3. The second area F2 is an area on the
lower side of the rotational axis R in FIG. 3.
[0044] As shown in FIG. 2, the first blower 60 feeds the air AR1
also to the light modulation units 4R, 4G, and 4B as the cooling
target. In other words, in the present embodiment, the first blower
60 is a cooling blower for feeding the air AR1 to the cooling
target. The first blower 60 is not particularly limited providing
the first blower 60 is capable of feeding the air AR1, and can be,
for example, an axial fan or a centrifugal fan.
[0045] The heat exchanger 30 is a section where the refrigerant W
is generated. FIG. 5 is a partial cross-sectional perspective view
showing the heat exchanger 30. As shown in FIG. 5, the heat
exchanger 30 has a circulation part 31, a first lid part 32, and a
second lid part 33.
[0046] The circulation part 31 has a plurality of pipe parts 31a
each having a tubular shape extending in one direction. In the
present embodiment, the one direction in which the pipe parts 31a
extend is, for example, perpendicular to the rotational axis
direction DR. The pipe parts 31a each open on both sides in the one
direction in which the pipe parts 31a extend. A shape of a
cross-sectional surface of the pipe part 31a perpendicular to the
one direction in which the pipe parts 31a extend is, for example, a
circular shape. It should be noted that in the following
description, the one direction in which the pipe parts 31a extend
is referred to as an "extension direction DE," and is arbitrarily
represented by a DE axis in the drawings. The first area F1 and the
second area F2 described above are separated in the extension
direction DE perpendicular to the rotational axis direction DR with
reference to the rotational axis R.
[0047] In the present embodiment, the circulation part 31 is formed
of a plurality of layers each formed of the plurality of pipe parts
31a arranged 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 part 31 is smaller than, for example, the dimension in
the rotational axis direction DR of the circulation part 31, and is
the smallest of the dimensions of the circulation part 31 in the
direction perpendicular to the extension direction DE.
[0048] The first lid part 32 is coupled to an end part on one side
(+DE side) in the extension direction DE in the circulation part
31. The first lid part 32 has a rectangular solid box-like shape
elongated in the rotational axis direction DR. Inside the first lid
part 32, one ends in the extension direction DE of the pipe parts
31a open. As shown in FIG. 3, inside the first lid part 32, there
is disposed a partition part 32a. The partition part 32a separates
the inside of the first lid part 32 into a first space S1 and a
second space S2 arranged side by side in the rotational axis
direction DR. In FIG. 3, the first space S1 is located on the right
side (+DR side) of the second space S2.
[0049] The first lid part 32 is provided with a communication hole
32b for communicating the first space S1 and the inside of the
circulation duct 26 with each other. The first lid part 32 is
provided with a communication hole 32c for communicating the second
space S2 and the inside of the circulation duct 25 with each
other.
[0050] The second lid part 33 is coupled to an end part on the
other side (-DE side) in the extension direction DE in the
circulation part 31, namely an end part on an opposite side to the
side where the first lid part 32 is coupled to the circulation part
31. As shown in FIG. 5, the second lid part 33 has a rectangular
solid box-like shape elongated in the rotational axis direction DR.
Inside the second lid part 33, the other ends in the extension
direction DE of the pipe parts 31a open. Unlike the first lid part
32, the inside of the second lid part 33 is not partitioned. The
inside of the second lid part 33 is communicated with each of the
first space S1 and the second space S2 of the first lid part 32 via
the inside of each of the pipe parts 31a of the circulation part
31. The second lid part 33 is coupled to the refrigerant sender 50.
Thus, the heat exchanger 30 is coupled to the refrigerant sender
50. It should be noted that in FIG. 5, a wall on the other side in
the extension direction DE in the second lid part 33 is
omitted.
[0051] As shown in FIG. 3, the circulation duct 26 is a duct
disposed on one side (+DR side) of the moisture
absorption/desorption member 40 in the rotational axis direction
DR. The circulation duct 26 has an inflow port opening on the other
side (-DR side) in the rotational axis direction DR toward a part
of the moisture absorption/desorption member 40 located in the
second area F2. The circulation duct 26 has an outflow port to be
communicated with the communication hole 32b of the first lid part
32.
[0052] The circulation duct 25 is a duct disposed on the other side
(-DR side) of the moisture absorption/desorption member 40 in the
rotational axis direction DR. The circulation duct 25 has an
outflow port opening on the one side (+DR side) in the rotational
axis direction DR toward the part of the moisture
absorption/desorption member 40 located in the second area F2. The
circulation duct 25 has an inflow port to be communicated with the
communication hole 32c of the first lid part 32.
[0053] The heater 22 has a heating main body part 22a. The heating
main body part 22a is disposed inside the circulation duct 25. The
heating main body part 22a is disposed on the other side (-DR side)
of the part of the moisture absorption/desorption member 40 located
in the second area F2 in the rotational axis direction DR. The
heating main body part 22a is, for example, an electric heater. The
heating main body part 22a heats an inside atmosphere (air) of the
circulation duct 25. In the present embodiment, the heater 22 has
the second blower 23.
[0054] The second blower 23 is disposed inside the circulation duct
26. The second blower 23 is disposed on the one side (+DR side) of
the part of the moisture absorption/desorption member 40 located in
the second area F2 in the rotational axis direction DR. The second
blower 23 is, 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 blower 23 toward the other side (-DE side)
in the extension direction DE from an exhaust port 23a. The exhaust
port 23a opens in the communication hole 32b of the first lid part
32. The second blower 23 feeds the air to the first space S1 via
the communication hole 32b.
[0055] The air discharged from the second blower 23 to the first
space S1 is the air having been taken in from the other side (-DR
side) in the rotational axis direction DR of the second blower 23
via the inflow port of the circulation duct 26, and is the air
having passed through the part of the moisture
absorption/desorption member 40 located in the second area F2. In
other words, the second blower 23 makes the air pass through the
part of the moisture absorption/desorption member 40 located in the
second area F2 different from the first area F1, and then feeds the
air to the heat exchanger 30. In the present embodiment, the air
which has not passed the part of the moisture absorption/desorption
member 40 located in the second area F2 flows inside the
circulation duct 25. Therefore, the heating main body part 22a
heats the air which has not passed the part of the moisture
absorption/desorption member 40 located in the second area F2.
[0056] As described above, in the present embodiment, the heater 22
feeds the air which has been heated by the heating main body part
22a to the part of the moisture absorption/desorption member 40
located in the second area F2 by the second blower 23 to thereby
heat the part of the moisture absorption/desorption member 40
located in the second area F2. Thus, the second blower 23 feeds the
ambient air of the part heated by the heater 22 in the moisture
absorption/desorption member 40 to the heat exchanger 30.
[0057] The air which has flowed into the heat exchanger 30 from the
second blower 23 via the first space S1 passes inside the pipe
parts 31a communicated with the first space S1 out of the plurality
of pipe parts 31a, and then inflows into the inside of the second
lid part 33. The air which has flowed into the inside of the second
lid part 33 passes through the inside of the pipe parts 31a
communicated with the second space S2 out of the plurality of pipe
parts 31a, then inflows into the second space S2, and then inflows
into the inside of the circulation duct 25 from the communication
hole 32c. The air having flowed into the inside of the circulation
duct 25 is heated by the heating main body part 22a, then passes
through the part of the moisture absorption/desorption member 40
located in the second area F2 once again, then inflows into the
inside of the circulation duct 26, and is then taken in by the
second blower 23.
[0058] As described hereinabove, in the present embodiment, the
refrigerant generator 20 has a circulation channel 27 through which
the air discharged from the second blower 23 circulates. The
circulation channel 27 is constituted by at least the circulation
ducts 25, 26 and the heat exchanger 30. The circulation channel 27
passes the heating main body part 22a, the moisture
absorption/desorption member 40, and the heat exchanger 30.
Although a narrow gap is provided between the moisture
absorption/desorption member 40 and each of the circulation ducts
25, the circulation channel 27 is substantially sealed, and thus,
the air from the outside is prevented from inflowing into the
inside of the circulation channel 27. It should be noted that in
the following description, the air which has been discharged from
the second blower 23 and then circulates through the circulation
channel 27 is referred to as air AR2.
[0059] The cooling duct 21 is a duct having an inflow port disposed
on the one side (+DR side) of the part of the moisture
absorption/desorption member 40 located in the first area F1 in the
rotational axis direction DR. Into the cooling duct 21, there
inflows the air AR1 which has been discharged from the first blower
60, and has passed through the part of the moisture
absorption/desorption member 40 located in the first area F1. The
cooling duct 21 extends from an area on one side of the part of the
moisture absorption/desorption member 40 located in the first area
F1 toward the heat exchanger 30.
[0060] The cooling duct 21 has a cooling passage part 21a extending
in the rotational axis direction DR. In the cooling passage part
21a, there is disposed the circulation part 31 of the heat
exchanger 30 so as to penetrate in the extension direction DE.
Thus, in the inside of the cooling passage part 21a, there is
disposed the circulation part 31. The air AR1 passing through the
cooling passage part 21a is made to blow against the outside
surface of the circulation part 31, and then passes through the
circulation part 31 in the rotational axis direction DR. Thus, the
circulation part 31 is cooled by the air AR1. In other words, the
heat exchanger 30 is cooled by the air AR1 which has been
discharged from the first blower 60, and then passed through the
moisture absorption/desorption member 40. In FIG. 3, the air AR1
passes through the circulation part 31 from the right side to the
left side in the cooling passage part 21a. An end part on the other
side (-DR side) in the rotational axis direction DR in the cooling
passage part 21a opens. The opening of the cooling passage part 21a
is, for example, an outflow port of the cooling duct 21.
[0061] When the air AR1 is fed to the part of the moisture
absorption/desorption member 40 located in the first area F1 from
the first blower 60, the steam included in the air AR1 is absorbed
by the part of the moisture absorption/desorption member 40 located
in the first area F1. The part of the moisture
absorption/desorption member 40 having absorbed the steam as the
moisture moves from the first area F1 to the second area F2 by the
motor 24 rotating the moisture absorption/desorption member 40.
Then, through the part of the moisture absorption/desorption member
40 located in the second area F2, there passes the air AR2 which
has been heated by the heating main body part 22a, and is
relatively high in temperature. Thus, the moisture having been
absorbed by the moisture absorption/desorption member 40 evaporates
to be released to the air AR2.
[0062] The air AR2 including the steam which has been absorbed from
the air AR1 by passing through the moisture absorption/desorption
member 40 is fed by the second blower 23 to the heat exchanger 30.
The air AR2 having flowed into the heat exchanger 30 from the first
space S1 flows through the circulation part 31. More particularly,
the air AR2 flows through the pipe parts 31a of the circulation
part 31. The circulation part 31 is cooled from the outside by the
air AR1 flowing along the rotational axis direction DR through the
cooling passage part 21a of the cooling duct 21.
[0063] When the circulation part 31 is cooled, the air AR2 which
flows through the pipe parts 31a and is relatively high in
temperature is cooled, and thus, the steam having been included in
the air AR2 is condensed to the water as a fluid, namely the
refrigerant W. In such a manner, the heat exchanger 30 is cooled to
thereby generate the refrigerant W from the air AR2 having flowed
into the heat exchanger 30.
[0064] In the present embodiment, the refrigerant sender 50 is
formed of a porous member, and transmits the refrigerant W due to a
capillary action. As the material of the refrigerant sender 50,
there can be cited, for example, polypropylene, cotton, and porous
metal. It is preferable for the material of the refrigerant sender
50 to be a material capable of making the surface tension of the
refrigerant sender 50 relatively high. As shown in FIG. 5, the
refrigerant sender 50 has a first trapping part 51, a second
trapping part 52, a third trapping part 53, and a coupling part
54.
[0065] The first trapping part 51 is fixed to an edge part on the
one side (+DE side) in the extension direction DE in the inside
surface of the first lid part 32. The first trapping part 51 is
shaped like a thin belt, and is formed along the edge part of the
first lid part 32 to have a rectangular frame shape. The second
trapping part 52 is fixed to an edge part on the other side (-DE
side) in the extension direction DE in the inside surface of the
second lid part 33. The second trapping part 52 is shaped like a
thin belt, and is formed along the edge part of the second lid part
33 to have a rectangular frame shape.
[0066] The third trapping part 53 extends from the first trapping
part 51 to the second trapping part 52 through the inside of the
pipe part 31a to couple the first trapping part 51 and the second
trapping part 52 to each other. The third trapping part 53 is
shaped like a thin belt extending in the extension direction DE. In
the present embodiment, the third trapping part 53 is disposed
inside one of the pipe parts 31a as shown in FIG. 5, but this is
not a limitation. The third trapping part 53 can be disposed inside
some of the pipe parts 31a, or can also be disposed inside all of
the pipe parts 31a. When the third trapping part 53 is disposed
inside some of the pipe parts 31a, it is also possible for the
third trapping part 53 to be disposed inside two or more of the
pipe parts 31a.
[0067] The coupling part 54 is a part for coupling the refrigerant
generator 20 and the cooling target to each other. In the present
embodiment, the coupling part 54 is coupled to the second trapping
part 52, and projects from the inside of the second lid part 33 to
the outside of the second lid part 33 so as to penetrate the wall
of the second lid part 33. As shown in FIG. 6, the coupling part 54
projecting to the outside of the second lid part 33 extends to the
light modulation unit 4G as the cooling target. FIG. 6 is a
perspective view showing the light modulation units 4R, 4G, and 4B,
and the light combining optical system 5. The coupling part 54 is
shaped like a thin belt. The width of the coupling part 54 is
larger than, for example, the width of the first trapping part 51,
the width of the second trapping part 52, and the width of the
third trapping part 53.
[0068] Then, the light modulation units 4R, 4G, and 4B 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 device 6,
namely a direction parallel to the projection direction of the
projection optical device 6, 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.
[0069] 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.
[0070] FIG. 7 is a diagram of the light modulation unit 4G viewed
from a light incident side. FIG. 8 is a diagram showing the light
modulation unit 4G, and corresponds to an VIII-VIII cross-sectional
view in FIG. 7.
[0071] As shown in FIG. 6, the light modulation unit 4R, the light
modulation unit 4G, and the light modulation unit 4B as the cooling
target are disposed so as to surround the light combining optical
system 5. The light modulation unit 4R and the light modulation
unit 4B are disposed across the light combining optical system 5
from each other in the width direction Y. The light modulation unit
4G is disposed on the light incident side (-X side) in the optical
axis direction X of the light combining optical system 5. Since the
structure of the light modulation unit 4R, the structure of the
light modulation unit 4G, and the structure of the light modulation
unit 4B are substantially the same as each other except the
arrangement position and the arrangement posture, in the following
description, the light modulation unit 4G is described alone as a
representative in some cases.
[0072] The light modulation unit 4G has a holding frame 80 for
holding the light modulator 4GP. As shown in FIG. 6 through FIG. 8,
the holding frame 80 is shaped like a substantially rectangular
solid flat in a direction in which the light enters the light
modulator 4GP and elongated in the vertical direction Z. The
direction in which the light enters the light modulator 4GP is, for
example, the optical axis direction X.
[0073] As shown in FIG. 8, the holding frame 80 has a through hole
81 penetrating the holding frame 80 in the incident direction of
the light. On the edge on the light incident side (-X side) of the
through hole 81, there is disposed a step part 83 where the width
of the through hole 81 increases. The light modulator 4GP is fitted
in the step part 83 and held by the holding frame 80. As shown in
FIG. 7, in the portions on the both sides in the vertical direction
Z in the surface on the light incident side of the holding frame
80, there are formed insertion grooves 82a, 82b.
[0074] As shown in FIG. 6 through FIG. 8, the projector 1 is
further provided with a cooling promotion section 70 installed in
the light modulation unit 4G as the cooling target. The cooling
promotion section 70 has a refrigerant holder 71 and a fixation
member 72. The refrigerant holder 71 is attached to a surface of
the holding frame 80 of the light modulation unit 4G as the cooling
target. In the present embodiment, the refrigerant holder 71 is
disposed on a surface on the light incident side (-X side) of the
light modulator 4GP in the holding frame 80. The refrigerant holder
71 is formed of a porous member for retaining the refrigerant W. As
the material of the refrigerant holder 71, there can be cited, for
example, polypropylene, cotton, and porous metal. The material of
the refrigerant holder 71 can be made the same as the material of,
for example, the refrigerant sender 50. It is preferable for the
material of the refrigerant holder 71 to be a material capable of
making the surface tension of the refrigerant holder 71 relatively
high.
[0075] FIG. 9 is a diagram showing the refrigerant holder 71. As
shown in FIG. 9, the refrigerant holder 71 has a main body part 71a
shaped like a rectangular frame, and insertion parts 71b, 71c
disposed in end parts on both sides in the vertical direction Z in
the main body part 71a. As shown in FIG. 8, the main body part 71a
covers a part of the surface on the light incident side (-X side)
of the light modulator 4GP in the holding frame 80. A portion on an
inner edge side in the main body part 71a covers an outer edge
portion of the light modulator 4GP. The insertion part 71b is
folded, and is inserted in the insertion groove 82a of the holding
frame 80. The insertion part 71c is folded, and is inserted in the
insertion groove 82b of the holding frame 80.
[0076] The fixation member 72 is a member for fixing the
refrigerant holder 71. As shown in FIG. 6 and FIG. 8, the fixation
member 72 is a plate like member. The fixation member 72 is made
of, for example, metal. The fixation member 72 has a frame part 72a
shaped like a rectangular frame, attachment parts 72b, and
insertion parts 72c. As shown in FIG. 7 and FIG. 8, the frame part
72a covers an outer edge part of the refrigerant holder 71. The
holding frame 80, the refrigerant holder 71, and the frame part 72a
are stacked on one another in a direction (the optical axis
direction X) of the light passing through the light modulation unit
4G. In the following description, the direction in which the
holding frame 80, the refrigerant holder 71, and the frame part 72a
are stacked on one another is simply referred to as a "stacking
direction." The fixation member 72 fixes the refrigerant holder 71
by sandwiching the refrigerant holder 71 between the frame part 72a
and the holding frame 80 in the stacking direction (the optical
axis direction X).
[0077] An inner edge of the frame part 72a is disposed on the outer
side of an inner edge of the refrigerant holder 71. Therefore,
apart of the refrigerant holder 71, namely a portion on the inner
side of the frame part 72a in the present embodiment, is exposed
when viewed from the fixation member 72 side in the stacking
direction.
[0078] As shown in FIG. 6 and FIG. 8, the attachment parts 72b are
respectively provided to both end parts in the width direction Y in
the both end parts in the vertical direction Z of the frame part
72a. The attachment parts 72b each project from the frame part 72a
toward the holding frame 80 (+X side). The attachment parts 72b are
respectively engaged with protrusions disposed on the side surfaces
of the holding frame 80. Thus, the fixation member 72 is fixed to
the holding frame 80.
[0079] The insertion parts 72c are disposed on both end parts in
the vertical direction Z of the frame part 72a. The insertion parts
72c each project from the frame part 72a toward the holding frame
80 (+X side). The insertion parts 72c are respectively inserted in
the insertion grooves 82a, 82b of the holding frame 80. The
insertion parts 72c press the insertion parts 71b, 71c of the
refrigerant holder 71 inside the insertion grooves 82a, 82b,
respectively.
[0080] The cooling promotion section 70 is provided to each of the
light modulation units 4R, 4G, and 4B. In other words, the
refrigerant holder 71 and the fixation member 72 are provided to
each of the light modulation units 4R, 4G, and 4B. As shown in FIG.
9, the refrigerant holder 71G provided to the light modulation unit
4G out of the light modulation units 4R, 4G, and 4B is coupled to
the refrigerant sender 50. More particularly, a coupling part 54 of
the refrigerant sender 50 is coupled to a lower end part of the
refrigerant holder 71G.
[0081] The refrigerant holder 71B attached to the light modulation
unit 4B and the refrigerant holder 71R attached to the light
modulation unit 4R are substantially the same as the refrigerant
holder 71G attached to the light modulation unit 4G except the
point that the coupling part 54 is not coupled thereto.
[0082] In the present embodiment, on both sides of the refrigerant
holder 71G attached to the light modulation unit 4G, there are
disposed the junction parts 73a, 73b to which the refrigerant
holder 71B attached to the light modulation unit 4B and the
refrigerant holder 71R attached to the light modulation unit 4R are
respectively joined. The junction parts 73a, 73b are each made of a
porous member.
[0083] The junction part 73a joins the refrigerant holder 71G
attached to the light modulation unit 4G and the refrigerant holder
71B attached to the light modulation unit 4B to each other. Thus,
the refrigerant holder 71B is coupled to the coupling part 54 of
the refrigerant sender 50 via the refrigerant holder 71G. As shown
in FIG. 6, the junction part 73a is provided with a cover part 74
for covering the junction part 73a. The cover part 74 is, for
example, a film made of resin.
[0084] The junction part 73b joins the refrigerant holder 71
attached to the light modulation unit 4G and the refrigerant holder
71 attached to the light modulation unit 4R to each other. Thus,
the refrigerant holder 71R is coupled to the coupling part 54 of
the refrigerant sender 50 via the refrigerant holder 71G. Although
not shown in the drawings, the junction part 73b is also provided
with the cover part 74 similarly to the junction part 73a.
[0085] The refrigerant W generated by the refrigerant generator 20
is transmitted to the refrigerant holder 71G using the coupling
part 54 of the refrigerant sender 50. The refrigerant W transmitted
to the refrigerant holder 71G is transmitted to the refrigerant
holder 71B via the junction part 73a, and at the same time,
transmitted to the refrigerant holder 71R via the junction part
73b. In such a manner, the refrigerant W generated in the
refrigerant generator 20 is transmitted to the three light
modulation units 4R, 4G, and 4B. Then, the refrigerant W
transmitted to and then retained in the refrigerant holder 71 is
evaporated, and thus, the light modulation units 4R, 4G, and 4B as
the cooling target are cooled. More particularly, by the
refrigerant W retained in the refrigerant holder 71 evaporating,
the holding frame 80 attached with the refrigerant holder 71 is
cooled, and by the holding frame 80 being cooled, the light
modulators 4RP, 4GP, and 4BP held by the holding frame 80 are
cooled. Thus, it is possible to cool the light modulators 4RP, 4GP,
and 4BP as the cooling target with the cooler 10.
[0086] As shown in FIG. 2, the projector 1 is further provided with
a temperature sensor 91 capable of measuring the temperature of the
cooling target, and a controller 90 for controlling the cooler 10.
In the present embodiment, the temperature sensor 91 is provided to
each of the light modulation units 4R, 4G, and 4B as the cooling
target. The temperature sensors 91 are capable of respectively
measuring the temperature of the light modulation units 4R, 4G, and
4B as the cooling target. More particularly, the temperature
sensors 91 are capable of respectively measuring the temperature of
the light modulators 4RP, 4GP, and 4BP. The measuring result of
each of the temperature sensors 91 is transmitted to the controller
90.
[0087] In the present embodiment, the controller 90 controls the
refrigerant generator 20 based on the temperature of the cooling
target. The controller 90 controls at least one of the output of
the first blower 60, the output of the heater 22, and a cooling
degree by the heat exchanger 30 based on the temperature of the
light modulators 4RP, 4GP, and 4BP obtained from the temperature
sensors 91. In the present embodiment, the controller 90 controls
all of the output of the first blower 60, the output of the heater
22, and the cooling degree by the heat exchanger 30 based on the
temperature of the light modulators 4RP, 4GP, and 4BP.
[0088] The controller 90 controls a voltage to be applied to the
first blower 60 to thereby control the output of the first blower
60 and the cooling degree of the heat exchanger 30. When the
voltage to be applied to the first blower 60 increases, the output
of the first blower 60 increases, and the amount of the air AR1 fed
by the first blower 60 increases. Therefore, the amount of the air
AR1 fed to the moisture absorption/desorption member 40 increases,
and thus, it is possible to increase the amount of the steam
absorbed as moisture by the moisture absorption/desorption member
40 from the air AR1. Thus, it is possible to increase the amount of
the steam to be released to the air AR2 from the moisture
absorption/desorption member 40, and thus, it is possible to
increase the amount of the steam condensed in the heat exchanger
30. Therefore, it is possible to increase the amount of generation
of the refrigerant W in the refrigerant generator 20.
[0089] Further, when the voltage to be applied to the first blower
60 increases, the amount of the air AR1 blowing against the
circulation part 31 from the first blower 21 via the cooling duct
21 increases. Thus, it is possible to increase the cooling degree
of the heat exchanger 30, and thus, it is possible to further cool
the heat exchanger 30. Therefore, it is possible to further
condense the steam included in the air AR2 fed into the circulation
part 31, and thus, it is possible to increase the amount of
generation of the refrigerant W in the refrigerant generator
20.
[0090] In contrast, when the voltage to be applied to the first
blower 60 decreases, the output of the first blower 60 decreases,
and the amount of the air AR1 fed from the first blower 60 to the
moisture absorption/desorption member 40 and the circulation part
31 decreases. Thus, the amount of the steam absorbed as moisture by
the moisture absorption/desorption member 40 decreases, and at the
same time, the cooling degree by the heat exchanger 30 decreases.
Therefore, it is possible to decrease the amount of the steam
condensed in the heat exchanger 30, and thus, it is possible to
decrease the amount of generation of the refrigerant W in the
refrigerant generator 20.
[0091] The controller 90 controls the voltage to be applied to the
heating main body part 22a to thereby control the output of the
heater 22. When the voltage to be applied to the heating main body
part 22a increases, the output of the heater 22 increases, and it
is easier to heat the moisture absorption/desorption member 40 by
the heater 22. Therefore, it is possible to increase the amount of
the steam to be released from the moisture absorption/desorption
member 40 to the air AR2. Thus, in the heat exchanger 30, 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 generator 20. In contrast,
when the voltage to be applied to the heating main body part 22a
decreases, the output of the heater 22 decreases, and thus, the
amount of the steam to be released from the moisture
absorption/desorption member 40 to the air AR2 decreases.
Therefore, it is possible to decrease the amount of the steam
condensed in the heat exchanger 30, and thus, it is possible to
decrease the amount of generation of the refrigerant W in the
refrigerant generator 20.
[0092] FIG. 10 is a flowchart showing an example of a procedure of
controlling the controller 90 in the present embodiment. In the
present embodiment, the controller 90 performs cooling of the
cooling target by the cooler 10 with a goal of keeping the
temperature of the cooling target within a target temperature range
along the procedure shown in FIG. 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 projector 1 is in
operation. When the cooling target is the light modulators 4RP,
4GP, and 4BP as in the present embodiment, the target temperature
range is, for example, no higher than 40.degree. C. and no lower
than 60.degree. C.
[0093] As shown in FIG. 10, the controller 90 determines (step
St12) whether or not the temperature of the cooling target is
within the target temperature range after the projector 1 has
started up (step St11). In the present embodiment, the controller
90 determines whether or not the temperature of the light
modulators 4RP, 4GP, and 4BP is within the target temperature range
based on the measuring result by the temperature sensors 91. When
the temperature of the cooling target is within the target
temperature range (YES in the step St12), the controller 90 keeps
(step St13) the output of the refrigerant generator 20 in the
current output. In other words, the controller 90 keeps the output
of the first blower 60, the output of the heater 22, and the
cooling degree by the heat exchanger 30 in the current state
without making changes.
[0094] In contrast, when the temperature of the cooling target is
out of the target temperature range (NO in the step St12), the
controller 90 determines (step St14) whether or not the temperature
of the cooling target is higher than the target temperature range.
In the present embodiment, the controller 90 determines whether or
not the temperature of the light modulators 4RP, 4GP, and 4BP is
higher than the target temperature range based on the measuring
result by the temperature sensors 91.
[0095] It should be noted that in the present embodiment, the
controller 90 determines 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
modulators 4RP, 4GP, and 4BP even when the temperature is within
the target temperature range in the rest of the light
modulators.
[0096] When the temperature of the cooling target is higher than
the target temperature range (YES in the step St14), the controller
90 increases (step St15) the output of the refrigerant generator
20. In other words, the controller 90 increases the output of the
first blower 60, the output of the heater 22, and the cooling
degree by the heat exchanger 30. Specifically, the controller 90
raises the voltage to be applied to the first blower 60 and the
voltage to be applied to the heating main body part 22a.
[0097] The degree of increasing the output of the refrigerant
generator 20 can 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 generator 20 in 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 controller 90 to set the degree of increasing the output of
the refrigerant generator 20 so 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 generator 20
is.
[0098] In the present embodiment, the degree of increasing the
output of the refrigerant generator 20 means a voltage value raised
in the voltage to be applied to the first blower 60 and a voltage
value raised in the voltage to be applied to the heating main body
part 22a. The voltage value raised in the voltage to be applied to
the first blower 60 and the voltage value raised in the voltage to
be applied to the heating main body part 22a can be the same as
each other, or can also be different from each other.
[0099] In contrast, when the temperature of the cooling target is
lower than the target temperature range (NO in the step St14), the
controller 90 decreases (step St16) the output of the refrigerant
generator 20. In other words, the controller 90 decreases the
output of the first blower 60, the output of the heater 22, and the
cooling degree by the heat exchanger 30. Specifically, the
controller 90 lowers the voltage to be applied to the first blower
60 and the voltage to be applied to the heating main body part
22a.
[0100] The degree of decreasing the output of the refrigerant
generator 20 can 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 generator 20 in 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 controller 90 to set the degree of decreasing the output of
the refrigerant generator 20 so 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 generator 20
is.
[0101] In the present embodiment, the degree of decreasing the
output of the refrigerant generator 20 means a voltage value
lowered in the voltage to be applied to the first blower 60 and a
voltage value lowered in the voltage to be applied to the heating
main body part 22a. The voltage value lowered in the voltage to be
applied to the first blower 60 and the voltage value lowered in the
voltage to be applied to the heating main body part 22a can be the
same as each other, or can also be different from each other.
[0102] The degree of raising the output of the refrigerant
generator 20 in the step St15 and the degree of decreasing the
output of each of the sections in the step St16 can 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 blower 60 in the step St15 and the absolute
value of the decrement in the voltage to be applied to the first
blower 60 in the step St16 can 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
part 22a in the step St15 and the absolute value of the decrement
in the voltage to be applied to the heating main body part 22a in
the step St16 can be the same as each other, or can also be
different from each other.
[0103] In such a manner as described above, the controller 90
changes at least one of the output of the first blower 60, the
output of the heater 22, and the cooling degree by the heat
exchanger 30 when the temperature of the light modulation units 4R,
4G, and 4B as the cooling target is out of the target temperature
range. In the present embodiment, the controller 90 changes all of
the output of the first blower 60, the output of the heater 22, and
the cooling degree by the heat exchanger 30 when the temperature of
the cooling target is out of the target temperature range. Further,
the controller 90 increases at least one of the output of the first
blower 60, the output of the heater 22, and the cooling degree by
the heat exchanger 30 when 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 blower 60, the output of the
heater 22, and the cooling degree by the heat exchanger 30 when the
temperature of the cooling target is lower than the target
temperature range.
[0104] In the present embodiment, the controller 90 repeatedly
executes the control in the step St12 through the step St16
described above every predetermined time during the period when the
projector 1 is in operation. The predetermined time is, for
example, several seconds.
[0105] According to the present embodiment, it is possible for the
cooler 10 to 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 generator 20 to the cooling target with the
refrigerant sender 50. 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
cooler 10 compared to air cooling and liquid cooling.
[0106] 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 cooler 10,
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 projector 1 equipped with the cooler 10
excellent in cooling performance, small in size, and excellent in
quietness.
[0107] Further, according to the present embodiment, since the
refrigerant W can be generated in the refrigerant generator 20,
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
generator 20 to 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
projector 1.
[0108] Further, according to the present embodiment, it is possible
to absorb the steam included in the air AR1 fed from the first
blower 60 by the moisture absorption/desorption member 40, and it
is possible to release the moisture absorbed by the moisture
absorption/desorption member 40 in the air AR2 fed by the second
blower 23 as steam. Further, it is possible to generate the
refrigerant W by condensing the moisture released as steam in the
air AR2 using the heat exchanger 30. Thus, according to the present
embodiment, it is possible to generate the refrigerant W from the
air in the projector 1.
[0109] Further, according to the present embodiment, the heat
exchanger 30 is cooled by the air AR1 which has been discharged
from the first blower 60, and then passed through the moisture
absorption/desorption member 40. Therefore, it is unnecessary to
separately dispose a cooling section for cooling the heat exchanger
30, and thus, it is possible to suppress an increase in the number
of components of the projector 1. Further, it is possible to
prevent the sound noise generated from the projector 1 from
increasing compared to when additionally provide a blower as the
cooling section for cooling the heat exchanger 30.
[0110] Further, according to the present embodiment, the first
blower 60 is the cooling blower for feeding the air AR1 to the
light modulation units 4R, 4G, and 4B as the cooling target.
Therefore, it is easy to evaporate the refrigerant W transmitted to
the light modulation units 4R, 4G, and 4B with the air AR1, and it
is possible to further cool the light modulation units 4R, 4G, and
4B. Further, since it is unnecessary to separately provide the
cooling blower for cooling the cooling target in addition to the
first blower 60, it is possible to prevent the number of components
of the projector 1 from increasing, and it is possible to prevent
the sound noise from increasing.
[0111] Further, as described above, in the present embodiment, the
evaporation of the refrigerant W fed to the cooling target is
promoted using the first blower 60 as the intake fan for taking in
the external air inside the projector 1. Even when lowering the
output of the first blower 60, it is possible to obtain the cooling
performance equivalent to when the cooler 10 is not provided.
Therefore, it is possible to lower the output of the first blower
60 as the intake fan to thereby reduce the sound noise generated
from the first blower 60, and thus, it is possible to further
enhance the quietness of the projector 1.
[0112] Further, for example, in the refrigerant generator 20, when
the humidity of the air AR2 fed from the second blower 23 to the
heat exchanger 30 is relatively low, the refrigerant W is difficult
to be generated in some cases even when the heat exchanger 30 is
cooled. The humidity of the air AR2 to be fed to the heat exchanger
30 drops in some cases when, for example, the air outside the
projector 1 is mixed with the air AR2.
[0113] In this regard, according to the present embodiment, the
refrigerant generator 20 has the circulation channel 27 through
which the air AR2 discharged from the second blower 23 circulates.
Therefore, it is possible to prevent the air located outside the
projector 1 from entering the circulation channel 27 by
substantially sealing the circulation channel 27, and it is easy to
keep the humidity of the air AR2 fed to the heat exchanger 30 in a
relatively high state. Therefore, by cooling the heat exchanger 30,
it is possible to generate the refrigerant W in good condition.
[0114] Further, according to the present embodiment, the heater 22
has the heating main body part 22a for heating the air which has
not passed the part of the moisture absorption/desorption member 40
located in the second area F2, and the second blower 23. Therefore,
it is possible for the heater 22 to heat the part of the moisture
absorption/desorption member 40 located in the second area F2 by
feeding the air AR2 to the moisture absorption/desorption member 40
using the second blower 23. Thus, it is possible to heat the
moisture absorption/desorption member 40 using the heater 22 even
when disposing the heating main body part 22a at a position distant
from the moisture absorption/desorption member 40. Therefore, the
degree of freedom of the configuration of the heater 22 can be
enhanced.
[0115] 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 modulators
4RP, 4GP, and 4BP as in the present embodiment, when the
temperature of the light modulators 4RP, 4GP, and 4BP is higher
than the target temperature range, there is a possibility that the
light modulators 4RP, 4GP, and 4BP are damaged by the heat.
Further, when the temperature of the light modulators 4RP, 4GP, and
4BP is lower than the target temperature range, there is a
possibility that the response characteristics of the liquid crystal
panels of the light modulators 4RP, 4GP, and 4BP deteriorate to
cause a blur, a flicker, and so on in the color image (picture)
emitted from the projector 1. Therefore, there is a possibility
that the reliability of the projector 1 degrades.
[0116] In contrast, according to the present embodiment, the
controller 90 controls the refrigerant generator 20 based 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 generator 20 based 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 projector 1 from degrading.
[0117] Further, according to the present embodiment, the controller
90 controls at least one of the output of the first blower 60, the
output of the heater 22, and the cooling degree by the heat
exchanger 30 based on the temperature of the cooling target.
Therefore, it is possible for the controller 90 to control at least
one of an amount of the steam absorbed by the moisture
absorption/desorption member 40, an amount of the steam released to
the air AR2 from the moisture absorption/desorption member 40, and
an amount of the steam condensed in the heat exchanger 30. Thus, by
controlling the output or the like of each section of the
refrigerant generator 20, it is possible to easily control the
amount of the refrigerant W generated in the refrigerant generator
20. 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 projector 1 from
degrading.
[0118] Further, according to the present embodiment, the controller
90 changes at least one of the output of the first blower 60, the
output of the heater 22, and the cooling degree by the heat
exchanger 30 when 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 projector 1 from degrading.
[0119] More particularly, in the present embodiment, the controller
90 increases at least one of the output of the first blower 60, the
output of the heater 22, and the cooling degree by the heat
exchanger 30 when 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.
[0120] Further, in the present embodiment, the controller 90
decreases at least one of the output of the first blower 60, the
output of the heater 22, and the cooling degree by the heat
exchanger 30 when 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.
[0121] Further, according to the present embodiment, the controller
90 controls all of the output of the first blower 60, the output of
the heater 22, and the cooling degree by the heat exchanger 30
based on the temperature of the cooling target. Therefore, the
amount of the refrigerant W generated in the refrigerant generator
20 can 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 projector 1 from
degrading.
[0122] Further, according to the present embodiment, the cooling
target corresponds to the light modulators 4RP, 4GP, and 4BP.
Therefore, by controlling the refrigerant generator 20 based on the
temperature of the light modulators 4RP, 4GP, and 4BP, it is easy
to keep the temperature of the light modulators 4RP, 4GP, and 4BP
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 projector 1.
[0123] Further, according to the present embodiment, the
refrigerant generator 20 has the motor 24 for rotating the moisture
absorption/desorption member 40. Therefore, it is possible to
stably rotate the moisture absorption/desorption member 40 at a
constant speed. Thus, it is possible to make the part of the
moisture absorption/desorption member 40 located in the first area
F1 preferably absorb the steam from the air AR1, and at the same
time, it is possible to make the part of the moisture
absorption/desorption member 40 located in the second area F2
preferably release the moisture to the air AR2. Therefore, it is
possible to efficiently generate the refrigerant W.
[0124] Further, according to the present embodiment, the
refrigerant sender 50 transmits 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
projector 1 from increasing, and thus, it is easier to reduce the
size and the weight of the projector 1.
[0125] Further, according to the present embodiment, the
refrigerant sender 50 has the coupling part 54 made of the porous
material for coupling the refrigerant generator 20 and the cooling
target to each other. Therefore, it is possible to make the
coupling part 54 absorb the refrigerant W to transmit the
refrigerant W with the capillary action.
[0126] Further, according to the present embodiment, the
refrigerant sender 50 has the second trapping part 52 disposed
inside the second lid part 33. The second trapping part 52 is
coupled to the coupling part 54. Therefore, it is possible to
absorb the refrigerant W retained inside the second lid part 33
using the second trapping part 52 to transmit the refrigerant W to
the coupling part 54 using the capillary action. Thus, it is easy
to transmit the refrigerant W thus generated to the cooling target
without a waste.
[0127] Further, according to the present embodiment, the
refrigerant sender 50 has the first trapping part 51 disposed
inside the first lid part 32, and a third trapping part 53 for
coupling the first trapping part 51 and the second trapping part 52
to each other. Thus, it is possible to absorb the refrigerant W
retained inside the first lid part 32 using the first trapping part
51 to transmit the refrigerant W to the second trapping part 52 via
the third trapping part 53 using the capillary action. Therefore,
it is possible to transmit the refrigerant W retained inside the
first lid part 32 from the second trapping part 52 to the coupling
part 54 to 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.
[0128] Further, according to the present embodiment, the third
trapping part 53 passes through the pipe part 31a. Therefore, it is
possible to absorb the refrigerant W retained inside the pipe part
31a using the third trapping part 53 to transmit the refrigerant W
to the cooling target via the second trapping part 52 and the
coupling part 54. Therefore, it is easy to transmit the refrigerant
W thus generated to the cooling target with a fewer waste.
[0129] Further, according to the present embodiment, the width of
the coupling part 54 is larger than, for example, the width of the
first trapping part 51, the width of the second trapping part 52,
and the width of the third trapping part 53. Therefore, it is easy
to make the width of the coupling part 54 relatively large, and it
is possible to increase the amount of the refrigerant W which can
be transmitted by the coupling part 54. Therefore, it is easy to
transmit the refrigerant W to the cooling target using the
refrigerant sender 50, and it is easier to cool the cooling
target.
[0130] Further, on the other hand, it is easy to make the width of
the first trapping part 51, the width of the second trapping part
52, and the width of the third trapping part 53 relatively small.
Therefore, it is possible to reduce the amount of the refrigerant W
to be retained by the first trapping part 51, the second trapping
part 52, and the third trapping part 53. Thus, it is possible to
reduce the amount of the refrigerant W remaining inside the heat
exchanger 30 while being retained in the first trapping part 51,
the second trapping part 52, and the third trapping part 53, and it
is easy to transmit the refrigerant W thus generated to the cooling
target with a fewer waste.
[0131] Further, according to the present embodiment, there are
provided the refrigerant holders 71 which are respectively provided
to the light modulation units 4R, 4G, and 4B as the cooling target,
and retain the refrigerant W. Therefore, the refrigerant W
transmitted to the light modulation units 4R, 4G, and 4B can be
retained in the light modulation units 4R, 4G, and 4B by the
refrigerant holders 71 until 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 cooler 10.
[0132] Further, according to the present embodiment, the
refrigerant holders 71 are respectively attached to the surfaces of
the light modulation units 4R, 4G, and 4B as the cooling target,
and are made of the porous material. Further, at least a part of
each of the refrigerant holders 71 is exposed when viewed from the
refrigerant holder 71 side in the stacking direction. Therefore, it
is easy to evaporate the refrigerant W from the exposed part of the
refrigerant holder 71, and it is possible to further improve the
cooling performance of the cooler 10. Further, since the
refrigerant holders 71 are 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 holder 71 is disposed due
to the capillary action, and it is easier to cool the cooling
target.
[0133] Further, for example, when fixing the refrigerant holders 71
to the holding frames 80 with an adhesive, the adhesive is absorbed
by the refrigerant holders 71 to block the holes of the refrigerant
holders 71 made of the porous material in some cases. Therefore, it
becomes difficult for the refrigerant W to be absorbed by the
refrigerant holders 71, and it becomes difficult for the
refrigerant holders 71 to retain the refrigerant W in some
cases.
[0134] In contrast, according to the present embodiment, there are
provided the fixation members 72 each for sandwiching the
refrigerant holder 71 with the holding frame 80 to fix the
refrigerant holder 71. Therefore, it is possible to fix the
refrigerant holders 71 to the respective holding frames 80 without
using the adhesive. Thus, it is possible to prevent the refrigerant
holders 71 from becoming difficult to retain the refrigerant W.
Further, in the present embodiment, the fixation members 72 are
made of metal. Therefore, the fixation members 72 are relatively
high in thermal conductivity, and are easy to cool. Therefore, it
is easy for the temperature of the fixation members 72 to drop due
to the air AR1 from the first blower 60 and the evaporation of the
refrigerant W, and thus, it is easier to cool the cooling target
having contact with the fixation members 72.
[0135] Further, according to the present embodiment, the
refrigerant holder 71 is disposed on the surface on the light
incident side of the light modulator 4GP in the holding frame 80.
Therefore, it is possible to prevent the steam as the refrigerant W
evaporated from the refrigerant holder 71 from affecting the light
emitted from the light modulator 4GP to the light combining optical
system 5. Thus, it is possible to prevent the noise from occurring
in the image projected from the projector 1.
[0136] Further according to the present embodiment, the refrigerant
holders 71 are provided to the respective light modulation units
4R, 4G, and 4B thus disposed as the plurality of units, and there
are provided the junction parts 73a, 73b for joining the
refrigerant holders 71 to each other. Therefore, by coupling the
refrigerant sender 50 to one of the refrigerant holders 71, it is
possible to transmit the refrigerant W also to the rest of the
refrigerant holders 71. Thus, it is possible to simplify the
arrangement of the refrigerant sender 50 inside the projector
1.
[0137] Further, according to the present embodiment, the junction
parts 73a, 73b are provided with the covering parts 74 for
respectively covering the junction parts 73a, 73b. Therefore, it is
possible to prevent the refrigerant W moving along the junction
parts 73a, 73b from evaporating in the junction parts 73a, 73b.
Thus, it is possible to prevent the refrigerant W from evaporating
without making a contribution to cooling of the light modulation
units 4R, 4G, and 4B as the cooling target, and thus, it is
possible to prevent the refrigerant W thus generated from being
wasted.
[0138] It should be noted that in the present embodiment, the
coupling part 54 can be coated similarly to the junction parts 73a,
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
part 54 and the junction parts 73a, 73b to be coated in the
periphery with, for example, a tube. Further, it is also possible
for the coupling part 54 and the junction parts 73a, 73b to be
provided with a coating treatment for preventing the evaporation on
the respective surfaces.
Second Embodiment
[0139] The present embodiment is different from the first
embodiment in the control procedure by the controller 90, and in
the point that a humidity sensor 192 represented by the dashed-two
dotted lines in FIG. 2 is 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.
[0140] The humidity sensor 192 is provided to, for example, the
housing of the projector 1. The humidity sensor 192 is capable of
measuring the ambient humidity of the projector 1, namely the
humidity in the external environment in which the projector 1 is
installed. The measuring result of the humidity sensor 192 is
transmitted to the controller 90.
[0141] In the present embodiment, the controller 90 controls the
refrigerant generator 20 based on the ambient humidity of the
projector 1 obtained from the humidity sensor 192. In the present
embodiment, the controller 90 controls at least one of the output
of the first blower 60, the output of the heater 22, and the
cooling degree by the heat exchanger 30 based on the ambient
humidity of the projector 1. In the present embodiment, the
controller 90 controls all of the output of the first blower 60,
the output of the heater 22, and the cooling degree by the heat
exchanger 30 based on the ambient humidity of the projector 1. The
method of controlling the output of the first blower 60, the output
of the heater 22, and the cooling degree by the heat exchanger 30
is substantially the same as in the first embodiment.
[0142] FIG. 11 is a flowchart showing an example of the procedure
of controlling the controller 90 in the present embodiment.
[0143] As shown in FIG. 11, the controller 90 determines (step
St22) whether or not the ambient humidity of the projector 1 is
within a preset humidity range after the projector 1 has started up
(step St21). In the present embodiment, the controller 90
determines whether or not the ambient humidity of the projector 1
is within the preset humidity range based on the measuring result
by the humidity sensor 192.
[0144] 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 projector 1 is
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 generator 20 is 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 projector 1 is installed.
[0145] When the ambient humidity of the projector 1 is within the
preset humidity range (YES in the step St22), the controller 90
keeps (step St23) the output of the refrigerant generator 20 in the
current output. In other words, the controller 90 keeps the output
of the first blower 60, the output of the heater 22, and the
cooling degree by the heat exchanger 30 in the current state
without making changes.
[0146] In contrast, when the ambient humidity of the projector 1 is
out of the preset humidity range (NO in the step St22), the
controller 90 determines (step St24) whether or not the ambient
humidity of the projector 1 is higher than the preset humidity
range. In the present embodiment, the controller 90 determines
whether or not the ambient humidity of the projector 1 is higher
than the preset humidity range based on the measuring result by the
humidity sensor 192.
[0147] When the ambient humidity of the projector 1 is higher than
the preset humidity range (YES in the step St24), the controller 90
sets (step St25) the refrigerant generator 20 to a low-output mode.
The low-output mode is a mode in which the output of the
refrigerant generator 20 becomes lower than the output of the
refrigerant generator 20 when the humidity of the projector 1 is
within the preset humidity range. In other words, when the ambient
humidity of the projector 1 is higher than the preset humidity
range, the controller 90 makes the output of the first blower 60,
the output of the heater 22, and the cooling degree by the heat
exchanger 30 lower than the levels set when the ambient humidity of
the projector 1 is within the preset humidity range.
[0148] The output of the refrigerant generator 20 in 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
projector 1. When the output of the refrigerant generator 20 in the
low-output mode changes in accordance with the level of the ambient
humidity of the projector 1, the controller 90 sets the output of
the refrigerant generator 20 so that the higher the ambient
humidity of the projector 1 is, the lower the output of the
refrigerant generator 20 is. In this case, the change in output of
the refrigerant generator can change linearly with respect to the
ambient humidity of the projector 1, or can also change in a
stepwise fashion.
[0149] In contrast, when the ambient humidity of the projector 1 is
lower than the preset humidity range (NO in the step St24), the
controller 90 sets (step St26) the refrigerant generator 20 to a
high-output mode. The high-output mode is a mode in which the
output of the refrigerant generator 20 becomes higher than the
output of the refrigerant generator 20 when the humidity of the
projector 1 is within the preset humidity range. In other words,
when the ambient humidity of the projector 1 is lower than the
preset humidity range, the controller 90 makes the output of the
first blower 60, the output of the heater 22, and the cooling
degree by the heat exchanger 30 higher than the levels set when the
ambient humidity of the projector 1 is within the preset humidity
range.
[0150] The output of the refrigerant generator 20 in 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 projector 1. When the output of the refrigerant generator 20 in
the high-output mode changes in accordance with the level of the
ambient humidity of the projector 1, the controller 90 sets the
output of the refrigerant generator 20 so that the lower the
ambient humidity of the projector 1 is, the higher the output of
the refrigerant generator 20 is. In this case, the change in output
of the refrigerant generator can change linearly with respect to
the ambient humidity of the projector 1, or can also change in a
stepwise fashion.
[0151] In such a manner as described above, the controller 90
changes at least one of the output of the first blower 60, the
output of the heater 22, and the cooling degree by the heat
exchanger 30 when the ambient humidity of the projector 1 is out of
the preset humidity range. In the present embodiment, the
controller 90 changes all of the output of the first blower 60, the
output of the heater 22, and the cooling degree by the heat
exchanger 30 when the ambient humidity of the projector 1 is out of
the preset humidity range. Further, the controller 90 decreases at
least one of the output of the first blower 60, the output of the
heater 22, and the cooling degree by the heat exchanger 30 when the
ambient humidity of the projector 1 is higher than the preset
humidity range, and further, increases at least one of the output
of the first blower 60, the output of the heater 22, and the
cooling degree by the heat exchanger 30 when the ambient humidity
of the projector 1 is lower than the preset humidity range.
[0152] In the present embodiment, the controller 90 repeatedly
executes the control in the step St22 through the step St26
described above every predetermined time during the period when the
projector 1 is 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.
[0153] For example, when the ambient humidity of the projector 1 is
higher than the preset humidity range, the amount of the steam
included in the air AR1 taken in from the outside of the projector
1 by the first blower 60 becomes larger than when the ambient
humidity of the projector 1 is within the preset humidity range.
Therefore, the amount of the steam absorbed by the moisture
absorption/desorption member 40 from the air AR1 increases, and as
a result, the amount of generation of the refrigerant W in the
refrigerant generator 20 increases. 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 projector 1.
[0154] Further, for example, when the ambient humidity of the
projector 1 is lower than the preset humidity range, the amount of
the steam included in the air AR1 taken in from the outside of the
projector 1 by the first blower 60 becomes smaller. Therefore, the
amount of the steam absorbed by the moisture absorption/desorption
member 40 from the air AR1 decreases, and as a result, the amount
of generation of the refrigerant W in the refrigerant generator 20
decreases. 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.
[0155] In contrast, according to the present embodiment, the
controller 90 controls the refrigerant generator 20 based on the
ambient humidity of the projector 1. Therefore, it is possible to
control the amount of the refrigerant W to be generated in the
refrigerant generator 20 based on the ambient humidity of the
projector 1. Thus, it is possible to generate a preferable amount
of refrigerant W even when the ambient humidity of the projector 1
is 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 projector 1 from degrading. Further, it is
possible to prevent the refrigerant W from being leaked outside the
projector 1.
[0156] Further, according to the present embodiment, the controller
90 controls at least one of the output of the first blower 60, the
output of the heater 22, and the cooling degree by the heat
exchanger 30 based on the ambient humidity of the projector 1.
Therefore, similarly to the first embodiment, by controlling the
output or the like of each section of the refrigerant generator 20,
it is possible to easily control the amount of the refrigerant W
generated in the refrigerant generator 20. 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 projector 1 from degrading.
[0157] Further, according to the present embodiment, the controller
90 changes at least one of the output of the first blower 60, the
output of the heater 22, and the cooling degree by the heat
exchanger 30 when the ambient humidity of the projector 1 is out of
the preset humidity range. Therefore, when the ambient humidity of
the projector 1 is 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
projector 1 from degrading.
[0158] More particularly, in the present embodiment, the controller
90 decreases at least one of the output of the first blower 60, the
output of the heater 22, and the cooling degree by the heat
exchanger 30 when the ambient humidity of the projector 1 is higher
than the preset humidity range. Therefore, when the ambient
humidity of the projector 1 is 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.
[0159] Further, according to the present embodiment, the controller
90 increases at least one of the output of the first blower 60, the
output of the heater 22, and the cooling degree by the heat
exchanger 30 when the ambient humidity of the projector 1 is lower
than the preset humidity range. Therefore, when the ambient
humidity of the projector 1 is 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.
[0160] Further, according to the present embodiment, the controller
90 controls all of the output of the first blower 60, the output of
the heater 22, and the cooling degree by the heat exchanger 30
based on the ambient humidity of the projector 1. Therefore, the
amount of the refrigerant W generated in the refrigerant generator
20 can 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 projector 1 from degrading.
[0161] It should be noted that in the present embodiment, it is
also possible to adopt the configurations and methods described
below.
[0162] 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.
[0163] 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.
[0164] 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.
[0165] 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.
[0166] In the embodiments described above, it is assumed that the
cooling blower is the first blower 60 provided to the refrigerant
generator 20, but this is not a limitation. The refrigerant blower
can also be separately provided in addition to the blowers provided
to the refrigerant generator 20.
[0167] 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.
[0168] 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.
[0169] 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.
[0170] 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.
[0171] 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.
* * * * *