JP2011203519A - Cooling device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device which is improved in cooling efficiency and is reduced in size, and to provide a projector.SOLUTION: The cooling device 2 includes a cooling fan 20 generating cooling air, and a duct 30, allowing the cooling air generated by the cooling fan 20 to flow, to discharge the cooling air to an optical device 45. The duct 30 includes a sub-duct 31, allowing the cooling air generated by the cooling fan 20 to flow, and a main duct 32 discharging the cooling air flowing in from the sub-duct 31 to the optical device 45; the sub-duct 31 is connected to the main duct 32, at such a site that the center axis of the sub-duct 31 is deviated from the center axis of the main duct 32; and the main duct 32 discharges the cooling air flowing in from the sub-duct 31 after changing the flow state of the cooling air so as to be spiral.

Description

  The present invention relates to a cooling device and a projector including the cooling device.

  2. Description of the Related Art Conventionally, there is known a projector that modulates a light beam emitted from a light source with a light modulation device based on an image signal and projects an emitted optical image as image light. Such projectors are designed to have high brightness, and the amount of heat generated by light sources, light modulators, and the like is increasing. For this reason, it is more important than ever to cool these heated optical devices.

  Under such circumstances, in Patent Document 1, the cooling fan that generates the cooling air and the cooling air generated by the cooling fan are branched into the first cooling air and the second cooling air, and the first cooling air is supplied. The air cooling duct that flows into the entrance / exit side spaces A and B of the liquid crystal unit and the direction of the second cooling air are changed so that the inside of the entrance / exit side spaces A and B is different from the first cooling air. And a cooling device that cools the liquid crystal unit.

JP 2009-75212 A

  However, in Patent Document 1, the cooling air is branched into a first cooling air and a second cooling air, and the air cooling duct and the air guide plate are used to enter the entrance / exit side spaces A and B from different directions. Since it has to be made to flow in, the structure of the cooling device is likely to be complicated, and the cooling device is likely to be increased in size. Accordingly, there has been a demand for a cooling device and a projector that improve the cooling efficiency and can be miniaturized.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  (Application Example 1) A cooling device according to this application example is a cooling device that discharges cooling air to an object to be cooled, the cooling fan that generates the cooling air, and the cooling air that is generated by flowing the cooling air generated by the cooling fan. A duct for discharging the cooling air generated by the cooling fan, and a main duct for discharging the cooling air flowing in from the sub duct to the object to be cooled. On the other hand, the center axis of the sub duct is connected to a portion that is shifted from the center axis of the main duct.

  According to such a cooling device, the sub duct is connected to the main duct at a position where the central axis of the sub duct is shifted from the central axis of the main duct, and the main duct supplies the cooling air flowing from the sub duct to the cooling target. Discharge. With this structure, for example, the cooling air that was flowing as a laminar flow inside the sub duct can be converted into a turbulent flow inside the main duct by flowing it into the main duct from a portion where the central axis is shifted. it can. By cooling the cooling air converted into the turbulent flow from the main duct to the cooling target, the cooling efficiency can be improved as compared with the case of discharging the laminar cooling air to the cooling target. Moreover, since it is not necessary to discharge cooling air from different directions to the object to be cooled, the structure of the cooling device can be simplified and the size of the cooling device can be reduced.

  Application Example 2 In the cooling device according to the application example described above, it is preferable that the main duct discharges the main body by converting the flow state of the cooling air flowing from the sub duct into a spiral shape.

  According to such a cooling device, the cooling efficiency can be further improved by converting the flow state of the cooling air into a spiral turbulent flow and discharging it in the main duct.

  (Application example 3) In the cooling device according to the application example described above, a plurality of sub-ducts are provided, and the plurality of sub-ducts are in the same direction so that the flow direction of the cooling air flowing in the main duct is substantially the same direction. It is preferable that the central axis of each of the plurality of sub-ducts is connected to a portion shifted from the central axis of the main duct.

  According to such a cooling device, the flow state of the cooling air can be more efficiently converted into a spiral turbulent flow in the main duct. Accordingly, the cooling efficiency of the cooling target can be improved more efficiently.

  Application Example 4 In the cooling device according to the application example described above, it is preferable that a plurality of cooling fans are provided, and each of the plurality of cooling fans discharges cooling air to the corresponding plurality of sub-ducts.

  According to such a cooling device, it can be more efficiently converted into a spiral turbulent flow, and the cooling efficiency of the object to be cooled can be improved more efficiently.

  Application Example 5 In the cooling device according to the application example, two cooling fans and two sub ducts are provided, one cooling fan discharges cooling air to one sub duct, and the other cooling fan cools air to the other sub duct. The one sub-duct and the other sub-duct are preferably connected to the main duct at a location where the central axis of each sub-duct is shifted from the central axis of the main duct.

  According to such a cooling device, it can be efficiently converted into a spiral turbulent flow, and the cooling efficiency of the object to be cooled can be improved. Also, the configuration of the cooling device is simplified.

  Application Example 6 A projector according to this application example includes any one of the above-described cooling devices, a light source, and a light modulation device that modulates a light beam emitted from the light source based on an image signal. To do.

  According to such a projector, by providing the cooling device having the above-described effect, it is possible to efficiently cool the light source, the light modulation device, and the like that are generated as the objects to be cooled, and to reduce malfunction due to heat. Long life can be achieved.

FIG. 2 is a plan view schematically showing a configuration of an optical system of the projector according to the first embodiment. The schematic plan view which shows a cooling device. FIG. 3 is a schematic cross-sectional view showing a cooling device. The schematic plan view which shows the cooling device which concerns on 2nd Embodiment. The schematic plan view which shows the cooling device which concerns on 3rd Embodiment. The schematic plan view which shows the cooling device which concerns on 4th Embodiment.

Hereinafter, embodiments will be described with reference to the drawings.
(First embodiment)

  FIG. 1 is a plan view schematically showing the configuration of the optical system of the projector 1 according to the first embodiment. The configuration and operation of the optical system of the projector 1 will be briefly described with reference to FIG.

  The projector 1 is a device that modulates a light beam emitted from a light source based on an image signal and enlarges and projects it on a screen (not shown). The projector 1 includes an exterior casing (not shown) that constitutes an exterior. Inside the exterior casing, an optical unit 4, a cooling device 2 (see FIG. 2), and a control unit (not shown) that controls the operation of the projector 1. ) Including circuit components (not shown).

  The optical unit 4 of the present embodiment modulates and projects light based on an image signal under the control of the control unit. The optical unit 4 includes a light source device 41, an illumination optical device 42, a color separation optical device 43, a relay optical device 44, an optical device 45, an optical component housing 46, and a projection optical device 47.

  The light source device 41 includes a light source lamp 411 and a reflector 412. The light source device 41 reflects the light beam emitted from the light source lamp 411 by the reflector 412 and emits it to the illumination optical device 42. Note that the light source lamp 411 of the present embodiment employs a discharge lamp such as an ultrahigh pressure mercury lamp.

  The illumination optical device 42 is for making the illuminance uniform in a plane orthogonal to the illumination optical axis A with respect to the light beam emitted from the light source device 41. The illumination optical device 42 includes lens arrays 421 and 422, a polarization conversion element 424, and a superimposing lens 425. The illumination optical device 42 includes three field lenses 426. The field lens 426 is disposed in front of the three light modulation devices of the optical device 45, and converts each partial light beam emitted from the lens array 422 into a light beam parallel to its central axis.

  The color separation optical device 43 separates the illumination light flux from the illumination optical device 42 into three color light devices of red (R) light, green (G) light, and blue (B) light, and corresponding three light modulation devices. It guides light. The color separation optical device 43 includes dichroic mirrors 431 and 432 and a reflection mirror 433. Since the optical path length of the relay optical device 44 is longer than the optical path lengths of the other color lights with respect to the color light (R light in the present embodiment) separated by the color separation optical device 43, the relay optical device 44 is caused by light divergence or the like. The use efficiency of light is prevented from decreasing, and the light modulation device (in this embodiment, a light modulation device for R light) is led. The relay optical device 44 includes an incident side lens 441, a relay lens 443, and reflection mirrors 442 and 444.

  The optical device 45 modulates each color light incident on each light modulation device based on the image signal, and then synthesizes it with a color synthesis optical device. The optical device 45 includes three liquid crystal panels 451, three incident-side polarizing plates 452, three emission-side polarizing plates 453, and a cross dichroic prism 454 as a color synthesizing optical device that constitute a light modulation device. The three liquid crystal panels 451 include an R light liquid crystal panel 451R as an R light light modulation device, a G light liquid crystal panel 451G as a green light light modulation device, and a B light as a B light light modulation device. The liquid crystal panel 451B is used. Note that the three liquid crystal panels 451 constituting the light modulation device of the present embodiment adopt a transmission type.

  The projection optical device 47 has a projection lens 471 and enlarges and projects the light combined by the optical device 45 (color combining optical device) onto the screen. The optical component housing 46 has a predetermined illumination optical axis A set therein, and accommodates the optical devices 41 to 45 described above at predetermined positions with respect to the illumination optical axis A. The optical devices 41 to 45 and 47 described above are used as an optical system of various general projectors, and thus detailed description thereof is omitted.

  FIG. 2 is a schematic plan view showing the cooling device 2. FIG. 3 is a schematic sectional view showing the cooling device 2. In addition, FIG. 2 has shown the duct 30 of the cooling device 2 with sectional drawing. 3 is a cross-sectional view taken along the line AA shown in FIG. 2, and is a cross-sectional view of the cooling device 2 that cools the R light liquid crystal panel 451R. The configuration and operation of the cooling device 2 will be described with reference to FIGS.

  In the projector 1, including the light source device 41, the polarization conversion element 424, the optical device 45 (the liquid crystal panel 451, the incident side polarizing plate 452, the emission side polarizing plate 453) and the like generate heat due to the light emitted from the light source device 41. The cooling device 2 of this embodiment applies this optical device 45 as a cooling target.

  The cooling device 2 includes a cooling fan 20 that generates cooling air and a duct 30 that causes the cooling air generated by the cooling fan 20 to flow and discharge it to the optical device 45. In addition, the duct 30 includes a sub duct 31 that causes the cooling air generated by the cooling fan 20 to flow, and a main duct 32 that is connected to the sub duct 31 and discharges the cooling air flowing in from the sub duct 31 to the optical device 45. . Further, the duct 30 includes an intake duct (not shown) that flows outside air sucked from an intake port (not shown) installed in an exterior housing (not shown) of the projector 1 to the cooling fan 20.

  In the present embodiment, the cooling fan 20 includes two components, a first cooling fan 21 and a second cooling fan 22. The first cooling fan 21 and the second cooling fan 22 are sirocco fans. The sirocco fan has a structure that discharges outside air sucked in from the rotation axis direction in the direction of centrifugal force due to rotation.

  In the present embodiment, the sub duct 31 includes a first sub duct 311 and a second sub duct 312. The first sub duct 311 is connected between the first cooling fan 21 and the main duct 32 (described later). The second sub duct 312 is connected between the second cooling fan 22 and the main duct 32.

  The first sub duct 311 branches from the vicinity of the discharge port 211 of the first cooling fan 21 into three parts: an R sub duct 311R, a G sub duct 311G, and a B sub duct 311B. The second sub duct 312 branches from the vicinity of the discharge port 221 of the second cooling fan 22 into three parts: an R sub duct 312R, a G sub duct 312G, and a B sub duct 312B.

  The main duct 32 includes three main parts: an R main duct 32R, a G main duct 32G, and a B main duct 32B. As shown in FIG. 3, the R main duct 32R is formed in a substantially cylindrical shape, and is disposed below the R light liquid crystal panel 451R with the discharge port 321R facing the R light liquid crystal panel 451R. . The G main duct 32G and the B main duct 32B are also configured in the same manner as the R main duct 32R, and the liquid crystals corresponding to the discharge ports 321G and 321B are disposed below the G light liquid crystal panel 451G and the B light liquid crystal panel 451B. It is installed toward the panel 451.

  The B sub-duct 311B of the first sub-duct 311 and the B sub-duct 312B of the second sub-duct 312 are arranged such that the central axes of the B sub-ducts 311B and 312B are the same as the B main duct 32B. Each is connected to a portion shifted from the central axis. More specifically, “deviated from the central axis” means that the central axis B in the cross-sectional direction of the B main duct 32B and the central axis C in the cross-sectional direction of the B sub-duct 311B intersect, as shown in FIG. It means that the positional relationship is shifted. Similarly, the center axis B of the B main duct 32B and the center axis D in the cross-sectional direction of the B sub duct 312B are not crossed but are in a shifted positional relationship.

  In the following description, “the central axis of each of the B sub-ducts 311B and 312B is connected to a portion shifted from the central axis of the B main duct 32B with respect to the B main duct 32B”. “The B sub-ducts 311B and 312B are connected to a portion whose center axis is deviated from the B main duct 32B”.

  The G sub-duct 311G of the first sub-duct 311 and the G sub-duct 312G of the second sub-duct 312 are connected to the G-axis main duct 32G where the central axis is shifted. Similarly, the R sub-duct 311R of the first sub-duct 311 and the R sub-duct 312R of the second sub-duct 312 are connected to a portion whose center axis is deviated from the R main duct 32R.

  Further, as shown by arrows in FIG. 2, the B sub-ducts 311B and 312B are connected in a positional relationship in which the flow direction is substantially the same when the cooling air flowing into the B main duct 32B is synthesized. Yes. This connection structure is the same in the G main duct 32G and the R main duct 32R.

  As shown in FIG. 3, the first sub duct 311 and the second sub duct 312 are connected to the main duct 32 in an inclined state in the upward direction (the direction of the discharge port 321). Accordingly, when the cooling air that has flowed in the sub duct 31 flows into the main duct 32, it flows in the direction of the discharge port 321.

The operation of the cooling device 2 will be described.
As shown in FIG. 2, when the cooling fan 20 (the first cooling fan 21 and the second cooling fan 22) is driven, the outside air sucked from the intake port (not shown) passes through the intake duct (not shown). It flows and is introduced into the first cooling fan 21 and the second cooling fan 22.

  The outside air (cooling air) discharged from the discharge port 211 of the first cooling fan 21 flows through the first sub duct 311 and branches from the three R sub ducts 311R, the G sub duct 311G, and the B sub duct 311B. Flow inside. Similarly, the outside air (cooling air) discharged from the discharge port 221 of the second cooling fan 22 flows in the second sub-duct 312 and branches into three R sub-ducts 312R, a G sub-duct 312G, and a B sub-duct 312B. Flows inside. In addition, the flow state of the cooling air flowing through each of the branched ducts of the first sub duct 311 and the second sub duct 312 is a laminar flow.

  Here, for convenience of explanation, the R sub-ducts 311R and 312R and the R main duct 32R are taken up, and the flow of cooling air for cooling the R light liquid crystal panel 451R and the like of the optical device 45 will be described.

  As shown in FIGS. 2 and 3, the cooling air that has flowed in the R sub-ducts 311R and 312R flows into the R main duct 32R. As described above, the R sub-ducts 311R and 312R are connected to the R main duct 32R at a position shifted from the central axis, and the flow direction of the cooling air in the R main duct 32R is changed. They are connected so that they have approximately the same direction. And it connects in the state inclined in the discharge port 321R direction of the R main duct 32R.

  With this connection structure, each cooling air flowing into the R main duct 32R has different inflow portions, but as shown by solid and broken arrows in FIG. It is converted into a flow state, flows, and is discharged from the discharge port 321R. In the G main duct 32G and the B main duct 32B, the cooling air flows in the same manner as the R main duct 32R, the flow direction is the same direction, and the state is converted into a spiral flow state, and the discharge ports 321G, Each is discharged from 321B.

  Cooling air as spiral turbulent flow discharged from the discharge port 321R of the R main duct 32R is a liquid crystal panel for R light 451R, an incident side polarizing plate 452, and an emission side polarizing plate located above the discharge port 321R. By spraying on 453, the heat generated in the R light liquid crystal panel 451R, the incident side polarizing plate 452, and the exit side polarizing plate 453 is taken and cooled. Note that the cooling light as spiral turbulent flow discharged from the discharge ports 321G and 321B of the G main duct 32G and the B main duct 32B is also located above the G light liquid crystal panel 451G and the B light liquid crystal panel. 451B etc. are cooled similarly.

According to the first embodiment described above, the following effects can be obtained.
The cooling device 2 of the present embodiment includes a cooling fan 20 and a duct 30. The cooling fan 20 includes a first cooling fan 21 and a second cooling fan 22. The duct 30 includes a sub duct 31 and a main duct 32. The sub duct 31 includes a first sub duct 311 that branches into three and a second sub duct 312 that branches into three. The first sub duct 311 and the second sub duct 312 are connected to the main duct 32 at a position where the central axis is shifted, and the flow direction of the cooling air flowing in the main duct 32 is substantially the same direction. It is connected. As a result, the cooling air flowing as a laminar flow inside the sub duct 31 can be converted into a spiral flow state inside the main duct 32. The cooling air converted into the spiral turbulent flow is discharged from the main duct 32 to the optical device 45, thereby improving the cooling efficiency as compared with the case where the laminar cooling air is discharged to the optical device 45. Can be made.

  The cooling device 2 of the present embodiment has two main ducts 32 (for example, R main duct 32R), two sub ducts 31 (for example, first sub duct 311 (R sub duct 311R), and second sub duct 312 (for R). Subduct 312R)) is connected. Further, using the two cooling fans 20, the first cooling fan 21 is connected to the first sub duct 311, and the second cooling fan 22 is connected to the second sub duct 312. Thereby, the flow state of the cooling air can be efficiently converted into a spiral turbulent flow by the main duct 32, and the cooling efficiency of the optical device 45 can be improved.

  According to the cooling device 2 of the present embodiment, the cooling air may be discharged from one direction (downward) to the optical device 45, and it is not necessary to discharge the cooling air from different directions. The structure can be simplified and the cooling device 2 can be downsized.

  According to the cooling device 2 of the present embodiment, a spiral turbulent flow is blown to the optical device 45 as the cooling air, so that the optical device 45 (liquid crystal panel 451, incident light) is compared with the case where the laminar cooling air is blown. Adhesion of dust to the side polarizing plate 452 and the exit side polarizing plate 453) can be reduced.

According to the projector 1 of the present embodiment, by providing the cooling device 2 having the above-described effects, the optical device 45 can be efficiently cooled, and the malfunction of the optical device 45 due to heat is reduced and a long lifetime is achieved. Can be achieved. Further, since the adhesion of dust to the optical components such as the liquid crystal panel 451 can be reduced, the projected image quality can be maintained.
(Second Embodiment)

  FIG. 4 is a schematic plan view showing the cooling device 5 according to the second embodiment. FIG. 4 shows the duct 60 of the cooling device 5 in a sectional view. With reference to FIG. 4, the structure and operation | movement of the cooling device 5 are demonstrated.

  The cooling device 5 of the present embodiment is different in the configuration of the cooling fan 50 and the duct 60 from the configuration of the cooling device 2 of the first embodiment. The cooling device 5 of the present embodiment is configured as a device that cools one liquid crystal panel 451, the incident-side polarizing plate 452, and the emission-side polarizing plate 453 constituting the optical device 45 as a cooling target. Therefore, three cooling devices 5 are used for the three liquid crystal panels 451.

  As shown in FIG. 4, the cooling device 5 includes a cooling fan 50 and a duct 60. One cooling fan 50 is used, and a sirocco fan is adopted as in the first embodiment. The duct 60 includes a sub duct 61 and a main duct 62. The sub duct 61 is connected between the cooling fan 50 and the main duct 62.

  In this embodiment, the sub duct 61 is configured to be branched into two parts, a first sub duct 611 and a second sub duct 612, from the vicinity of the discharge port 501 of the cooling fan 50. Similar to the first embodiment, the first sub duct 611 and the second sub duct 612 are connected to a portion where the central axis is shifted with respect to the main duct 62, and the flow direction of the cooling air is substantially the same. Connected to.

  Further, the first sub-duct 611 and the second sub-duct 612 are connected to the main duct 62 in an inclined state in the same manner as in the first embodiment, and the cooling air flowing in the sub-duct 61 is When it flows into the duct 62, it flows upward.

  The main duct 62 is composed of one. As in the first embodiment, the main duct 62 is formed in a substantially cylindrical shape, and is disposed below the liquid crystal panel 451 with the discharge port (not shown) facing the liquid crystal panel 451.

  In other words, the cooling device 5 of the present embodiment has a structure in which two sub ducts 61 (first sub duct 611 and second sub duct 612) connected to one cooling fan 50 are connected to one main duct 62. .

The operation of the cooling device 5 will be described.
By driving the cooling fan 50, outside air sucked from an intake port (not shown) flows through the intake duct (not shown) and is introduced into the cooling fan 50. The outside air (cooling air) discharged from the discharge port 501 of the cooling fan 50 flows in the sub duct 61 and flows in the branched first sub duct 611 and second sub duct 612. In addition, the flow state of the cooling air flowing inside each duct of the first sub duct 611 and the second sub duct 612 is a laminar flow.

  Each cooling air that has flowed into the main duct 62 has a flow direction substantially the same, is converted into a spiral flow state, flows, and is discharged from a discharge port. The cooling air as a spiral turbulent flow discharged from the discharge port is blown to the R light liquid crystal panel 451R, the incident side polarizing plate 452, and the emission side polarizing plate 453, which are positioned above, for R light. The heat generated in the liquid crystal panel 451R, the incident side polarizing plate 452, and the emission side polarizing plate 453 is taken and cooled.

  The cooling device 5 is also applied to the other G light liquid crystal panel 451G and B light liquid crystal panel 451B to cool the G light liquid crystal panel 451G, the B light liquid crystal panel 451B, and the like. Can do.

  According to the second embodiment described above, the following effects can be obtained.

The cooling device 5 according to the present embodiment has a structure in which two sub ducts 61 (first sub duct 611 and second sub duct 612) connected to one cooling fan 50 are connected to one main duct 62. Also with such a cooling device 5, the cooling air can be converted into a spiral turbulent flow inside the main duct 62 and flowed. Then, the cooling air converted into the spiral turbulent flow is discharged from the main duct 62 to the optical device 45, thereby improving the cooling efficiency as compared with the case where the laminar cooling air is discharged to the optical device 45. Can be made.
(Third embodiment)

  FIG. 5 is a schematic plan view showing the cooling device 7 according to the third embodiment. In addition, FIG. 5 has shown the duct 70 of the cooling device 7 with sectional drawing. The configuration and operation of the cooling device 7 will be described with reference to FIG.

  The cooling device 7 of this embodiment differs in the structure of the duct 70 compared with 2nd Embodiment. Specifically, the duct 70 includes one sub duct 71 and one main duct 72. The sub duct 71 is connected between the cooling fan 50 and the main duct 72, and is connected to the main duct 72 at a portion where the central axis of the sub duct 71 is shifted from the central axis of the main duct 72.

As described above, the number of sub ducts 71 is not one, but one, and the main duct 72 is connected to a portion where the central axis of the sub duct 71 is shifted from the central axis of the main duct 72. It can be converted into a turbulent flow to flow and discharged. Therefore, even such a simple cooling device 7 can improve the cooling efficiency. Moreover, according to the structure of such a cooling device 7, a cooling device can be further reduced in size.
(Fourth embodiment)

  FIG. 6 is a schematic plan view showing the cooling device 8 according to the fourth embodiment. In addition, FIG. 6 has shown the duct 80 of the cooling device 8 with sectional drawing. The configuration and operation of the cooling device 8 will be described with reference to FIG.

  The cooling device 8 of this embodiment differs in the structure of the duct 80 compared with 3rd Embodiment. Specifically, the shape of the main duct 82 described later is different. The duct 80 includes a sub duct 81 and a main duct 82, and the sub duct 81 is connected between the cooling fan 50 and the main duct 82. The sub duct 81 is connected to the main duct 82 at a location where the central axis of the sub duct 81 is shifted from the central axis of the main duct 82.

  The main duct 82 has a hollow section and a substantially rectangular shape, and is formed with a round corner. Even the main duct 82 formed in this manner can be converted into a spiral turbulent flow inside the main duct 82 to flow and be discharged.

  In addition, it is not limited to the 1st-4th embodiment mentioned above, It is possible to add and implement various changes, improvements, etc. in the range which does not deviate from the summary. A modification will be described below.

  (Modification 1) The cooling devices 2, 5, 7, and 8 of the first to fourth embodiments apply the optical device 45 as a cooling target. However, the present invention is not limited to this, and the light source device 41, the polarization conversion element 424, a member that generates heat in the projector 1, and the like can be applied as the cooling target.

  (Modification 2) In the cooling device 5 of the second embodiment, the sub duct 61 (the first sub duct 611 and the second sub duct 612) has a central axis of each of the sub ducts 61 relative to the main duct 62. The first sub duct 611 and the second sub duct 612 are connected in parallel to each other at positions shifted from the central axis. However, the cooling air does not have to be connected substantially in parallel. When cooling air flows into the main duct 62 from the first sub duct 611 and the second sub duct 612, the flow direction of the cooling air is substantially the same in the main duct 62. What is necessary is just to be connected so that it may become. This also applies to the first embodiment.

  (Modification 3) The cooling device 5 of the second embodiment is converted into a spiral flow state inside the main duct 62. However, even if it is not converted into a spiral turbulent flow, it may be converted into a turbulent flow by turbulent laminar flow. This also applies to the first, third, and fourth embodiments. Thereby, although cooling efficiency is inferior compared with a spiral turbulent flow, it can improve cooling efficiency compared with a laminar flow.

  (Modification 4) In the cooling device 5 of the second embodiment, the sub duct 61 connected to the main duct 62 is connected to the first sub duct 611 and the second sub duct 612. However, the configuration is not limited to this, and three or more sub-ducts may be connected to the main duct. As a connection structure in this case, the plurality of sub ducts are connected to portions where the flow directions of the cooling air flowing in the main duct are substantially the same direction, and the central axes of the plurality of sub ducts are shifted from the central axis of the main duct. It is good to be done. This also applies to the first embodiment.

  (Modification 5) In the cooling device 2 of the first embodiment, three sub ducts (R sub duct 311R, G sub duct 311G, and B sub duct 311B) are connected to one first cooling fan 21. However, the present invention is not limited to this, and the number of sub-ducts connected to the cooling fan is not limited and can be set as appropriate. This also applies to the second to fourth embodiments.

  (Modification 6) The cooling devices 2, 5, 7, and 8 of the first to fourth embodiments have the optical device 45 as a cooling target, the liquid crystal panel 451, the incident-side polarizing plate 452, and the emission-side polarizing plate 453. Cooling is done by blowing cooling air directly. However, the present invention is not limited to this. For example, it can be applied to a case where a cooling device or the like that is cooled by attaching a heat radiating member such as a heat sink is used for cooling, and the heat radiating efficiency of the heat radiating member can be improved. . In that case, the heat dissipation member can be downsized.

  (Modification 7) In the optical unit 4 of the first to fourth embodiments, the optical device 45 adopts a so-called three-plate method using three light modulation devices corresponding to R light, G light, and B light. Yes. However, the present invention is not limited to this, and a single plate type light modulation device may be adopted. Further, a light modulation device for improving the contrast may be additionally employed.

  (Modification 8) In the optical unit 4 of the first to fourth embodiments, the optical device 45 employs a transmissive light modulation device (transmissive liquid crystal panel 451). However, the present invention is not limited to this, and a reflective light modulation device may be employed.

  (Modification 9) In the optical unit 4 of the first to fourth embodiments, a liquid crystal panel 451 is employed as a light modulation device. However, the present invention is not limited to this, and it is generally sufficient that it modulates an incident light beam based on an image signal. For example, other types of light modulation devices such as a micromirror type light modulation device can be employed. For example, a DMD (Digital Micromirror Device) can be adopted as the micromirror type light modulation device.

  (Modification 10) In the optical unit 4 of the first to fourth embodiments, a lens integrator optical system including lens arrays 421 and 422 is used as the illumination optical device 42 that equalizes the illuminance of the light beam emitted from the light source device 41. However, the present invention is not limited to this, and a rod integrator optical system including a light guide rod can also be used.

  (Modification 11) In the optical unit 4 of the first to fourth embodiments, the light source lamp 411 of the light source device 41 employs a discharge lamp such as an ultra-high pressure mercury lamp, but a laser diode, LED (Light Various solid light emitting elements such as an Emitting Diode), an organic EL (Electro Luminescence) element, and a silicon light emitting element may be employed.

  DESCRIPTION OF SYMBOLS 1 ... Projector, 2, 5, 7, 8 ... Cooling device, 20 ... Cooling fan, 21 ... 1st cooling fan, 22 ... 2nd cooling fan, 30 ... Duct, 31 ... Sub duct, 32 ... Main duct, 45 ... Optical 311 ... 1st subduct, 312 ... 2nd subduct.

Claims (6)

A cooling device that discharges cooling air to a cooling target,
A cooling fan for generating the cooling air;
A duct for causing the cooling air generated by the cooling fan to flow and discharging it to the object to be cooled,
The duct has a sub duct for flowing the cooling air generated by the cooling fan, and
A main duct that discharges the cooling air flowing in from the sub duct to the object to be cooled,
The cooling apparatus according to claim 1, wherein the sub duct is connected to the main duct at a position where a central axis of the sub duct is shifted from a central axis of the main duct. The cooling device according to claim 1,
The cooling apparatus according to claim 1, wherein the main duct discharges the cooling air flowing in from the sub duct by converting the flow state of the cooling air into a spiral shape. The cooling device according to claim 2,
A plurality of the sub-ducts,
The plurality of sub-ducts are arranged such that the central axis of each of the plurality of sub-ducts is relative to the main duct so that the flow direction of the cooling air flowing in the main duct is substantially the same direction. A cooling device, wherein each of the cooling devices is connected to a portion shifted from the central axis. The cooling device according to claim 3,
A plurality of the cooling fans;
The plurality of cooling fans discharge the cooling air to the corresponding plurality of sub-ducts, respectively. The cooling device according to claim 4,
Two each of the cooling fan and the sub duct,
One of the cooling fans discharges the cooling air to one of the sub ducts,
The other cooling fan discharges the cooling air to the other sub-duct,
The one sub-duct and the other sub-duct are characterized in that the central axis of each of the sub-ducts is connected to a portion of the main duct that is offset from the central axis of the main duct. Cooling system. The cooling device according to any one of claims 1 to 5,
A projector comprising: a light source; and a light modulation device that modulates a light beam emitted from the light source based on an image signal.

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