Projection system

Abstract

To provide a projection system which can be miniaturized.SOLUTION: A projection system includes a plurality of projectors arranged along a horizontal direction, a projection target on which an image is displayed by light projected from each of the plurality of projectors, and a cooling device that cools the plurality of projectors, wherein each of the plurality of projectors includes an exterior housing constituting an exterior, a light source, a light modulator that modulates light emitted from the light source, a projection optical device that projects light modulated by the light modulator, and a heat absorption device that absorbs heat of a cooling target that is at least one of the light source and the light modulator. The cooling device includes a heat transport device that transports heat absorbed by the heat absorption device included in each of the plurality of projectors to the outside of the exterior housing, and a heat radiation device that radiates heat transported by the heat transport device, and the heat radiation device is disposed outside the exterior housing included in each of the plurality of projectors.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to projection systems. [Background technology]

[0002] BACKGROUND ART Conventionally, a projection system including a plurality of projectors that project image light onto one screen has been known (see, for example, Patent Document 1). The projection system described in Patent Document 1 includes a group of multiple projectors, a screen on which lenticular lenses are arranged, and a control device.

[0003] The multiple projector groups are arranged in one direction. Each projector group includes a red projector that projects a red image, a green projector that projects a green image, and a blue projector that projects a blue image. These three projectors are arranged at a distance from each other in a direction perpendicular to the arrangement direction of the projector groups. The image light projected from each projector group is mixed on the screen, thereby displaying a full-color image on the screen. The projector groups are driven based on image signals input from a control device.

[0004] A lenticular lens is made up of multiple cylindrical lenses connected in the short direction, and is arranged on both sides of a screen. The lenticular lens directs the light of the image displayed on the screen in the direction of the arrangement of the parallax images, and emits it. The cylindrical lenses that make up the lenticular lens ensure that, of the images divided and displayed on the screen, all images projected from the same projector group are emitted at the same angle. This lenticular lens allows the image light projected from different projector groups to reach the viewer's right and left eyes. By projecting the images from each projector group as parallax images of the same object captured from different angles, the right and left eyes of the observer looking at the screen will see images of the object captured from different angles, allowing the observer to view a three-dimensional image of the object. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-72048 Summary of the Invention [Problem to be solved by the invention]

[0006] The projectors constituting each of the projector groups described in Patent Document 1 have heat sources such as light sources and liquid crystal light valves. To maintain the functionality of the projectors, it is necessary to cool the objects to be cooled, such as the light sources and liquid crystal light valves. However, if each projector is equipped with a cooling device, it becomes difficult to reduce the size of each projector, which in turn leads to a problem that the entire projection system tends to become larger. For this reason, there has been a demand for a projection system configuration that can be made smaller. [Means for solving the problem]

[0007] A projection system according to one aspect of the present disclosure comprises a plurality of projectors arranged horizontally, a projection target on which an image is displayed by light projected from each of the plurality of projectors, and a cooling device that cools the plurality of projectors, each of the plurality of projectors comprising an exterior housing that forms the exterior, a light source, a light modulation device that modulates light emitted from the light source, a projection optical device that projects light modulated by the light modulation device, and a heat absorption device that absorbs heat from an object to be cooled, which is at least one of the light source and the light modulation device, and the cooling device comprises a heat transport device that transports heat absorbed by the heat absorption device provided in each of the plurality of projectors to the outside of the exterior housing, and a heat dissipation device that dissipates the heat transported by the heat transport device, and the heat dissipation device is arranged outside the exterior housing of each of the plurality of projectors. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a projection system according to a first embodiment. [Figure 2] FIG. 1 is a schematic diagram showing the internal configuration of a projector according to a first embodiment. [Figure 3] FIG. 1 is a schematic diagram showing the configuration of a light source device according to a first embodiment. [Figure 4] FIG. 2 is a plan view showing the configuration of the heat absorption device according to the first embodiment. [Figure 5] FIG. 3 is a schematic diagram showing the arrangement of projectors in the horizontal direction relative to the screen in the first embodiment. [Figure 6] FIG. 3 is a schematic diagram showing the arrangement of projectors in the vertical direction relative to the screen in the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [First embodiment] Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings. [Projection system configuration] FIG. 1 is a schematic diagram showing the configuration of a projection system 1 according to this embodiment. As shown in FIG. 1, the projection system 1 of this embodiment includes a projector group 2 including a plurality of projectors 3, a cooling device 5 including a heat transport device 6 and a heat dissipation device 7, and a screen 8 as a projection target, and projects an image from each projector 3 onto the screen 8 and displays an image based on the image light projected from each projector 3. Each component of the projection system 1 will be described below.

[0010] [Projector configuration] FIG. 2 is a schematic diagram showing the internal configuration of the projector 3. As shown in FIG. A plurality of projectors 3 are arranged in one direction to form a projector group 2. Each projector 3 projects image light toward a screen 8. As shown in FIG. 2 , the projector 3 includes an exterior housing 31, an image projection device 32, and a heat absorption device 40.

[0011] [Exterior casing configuration] The exterior housing 31 constitutes the exterior of the projector 3. The exterior housing 31 has a first surface 311, a second surface 312, a third surface 313, and a fourth surface 314, as well as a fifth surface and a sixth surface (not shown). The first surface 311 is an outer surface of the exterior housing 31 through which image light projected by the image projection device 32 passes. That is, the first surface 311 has a passage opening 3111 through which the image light passes. The second surface 312, the third surface 313, the fourth surface 314, the fifth surface, and the sixth surface are surfaces of the exterior housing 31 that are different from the first surface 311. The second surface 312 is the surface opposite to the first surface 311, and the third surface 313, the fourth surface 314, the fifth surface, and the sixth surface are surfaces that intersect with the first surface 311.

[0012] The exterior housing 31 further has a first connection portion 317 and a second connection portion 318 provided on the second surface 312. The first connection part 317 is connected to one of a plurality of branching paths 62 branching from a first transport path 61 of the heat transport device 6, which will be described later. The first connection part 317 is a joint configured to allow the branching path 62 to be detachably attached. The refrigerant circulating through the branching path 62 is introduced into the exterior housing 31 through the first connection part 317. The second connection part 318 is connected to one of the branch discharge paths 64 branching from the second transport path 63 of the heat transport device 6. The second connection part 318 is a joint configured to allow the branch discharge path 64 to be attached and detached. The second connection part 318 discharges the refrigerant that has circulated inside the exterior housing 31 to the branch discharge path 64. At least one of the first connecting portion 317 and the second connecting portion 318 may be provided with a valve for adjusting the flow rate of the refrigerant.

[0013] [Configuration of image projection device] The image projection device 32 projects image light corresponding to an image signal onto the screen 8. The image projection device 32 includes a light source device 33, a uniformization device 34, a color separation device 35, a relay device 36, an image forming device 37, a projection optical device 38, and an optical component housing 39.

[0014] The light source device 33 emits illumination light to the uniformizing device 34. The configuration of the light source device 33 will be described in detail later. The homogenizer 34 homogenizes the illuminance distribution of the light incident from the light source device 33. The homogenizer 34 includes a first lens array 341, a second lens array 342, a polarization conversion element 343, and a superimposing lens 344. Color separation device 35 separates the light incident from uniformization device 34 into red light LR, green light LG, and blue light LB. Color separation device 35 has dichroic mirrors 351 and 352 and a reflecting mirror 353. Blue light LB transmitted through dichroic mirror 351 is reflected by reflecting mirror 353 and enters blue field lens 371. Of the green light LG and red light LR reflected by dichroic mirror 351, green light LG reflected by dichroic mirror 352 enters green field lens 371.

[0015] The relay device 36 includes an incident-side lens 361, a reflecting mirror 362, a relay lens 363, and a reflecting mirror 364 that are provided in the optical path of the red light LR that has passed through the dichroic mirror 352, and guides the red light LR to a red field lens 371. Note that the relay device 36 may also be configured to pass, for example, blue light LB.

[0016] The image forming device 37 modulates each of the separated color lights and combines the modulated color lights to form image light. The image forming device 37 includes a field lens 371, an incident-side polarizing plate 372, a light modulation device 373, and an exit-side polarizing plate 374, each of which is provided for each of the color lights LR, LG, and LB, as well as one light combining device 375. That is, the image forming device 37 includes three light modulation devices 373.

[0017] The light modulation device 373 modulates the light emitted from the light source device 33. More specifically, the light modulation device 373 modulates the light emitted from a light source 331 of the light source device 33, which will be described later. Specifically, the three light modulation devices 373 include a light modulation device 373B that modulates blue light LB, a light modulation device 373G that modulates green light LG, and a light modulation device 373R that modulates red light LR. In this embodiment, the light modulation device 373 is a transmissive liquid crystal panel in which the light incident surface and the light exit surface are different, but it may also be a reflective liquid crystal panel in which the light incident surface and the light exit surface are the same. Furthermore, as long as the light modulation device is capable of forming image light according to image information, a light modulation device other than a liquid crystal, such as a device using a micromirror, for example, a DMD (Digital Micromirror Device), may be used. The light combining device 375 forms image light by combining the color lights modulated by the light modulation devices 373R, 373G, and 373B and passed through the output-side polarizing plate 374. The light combining device 375 outputs the combined image light to the projection optical device 38. In this embodiment, the light combining device 375 is a cross dichroic prism, but may also be configured with multiple dichroic mirrors.

[0018] The projection optical device 38 enlarges and projects the image light incident from the light combining device 375 onto the screen 8. The projection optical device 38 is configured as a lens assembly in which a plurality of lenses are arranged in a lens barrel. The optical component housing 39 holds the uniforming device 34, the color separation device 35, the relay device 36, and the image forming device 37. The image projection device 32 has an illumination optical axis Ax, which is a design optical axis, set therein, and the optical component housing 39 holds the above devices 34 to 37 at predetermined positions on the illumination optical axis Ax. The light source device 33 and the projection optical device 38 are arranged at predetermined positions on the illumination optical axis Ax.

[0019] [Light source configuration] FIG. 3 is a schematic diagram showing the configuration of the light source device 33. As shown in FIG. The light source device 33 emits illumination light WL toward the uniformizing device 34. As shown in FIG. 3 , the light source device 33 includes a light source 331, a diffuse transmission section 332, a light separation section 333, a first light-collecting element 334, a wavelength conversion device 335, a second light-collecting element 336, a diffusion optical member 337, a light source housing 338, and a heat-receiving member 339.

[0020] The light source device 33 has an optical axis Ax1 and an optical axis Ax2 that is perpendicular to the optical axis Ax1. A light source 331, a diffuse transmission section 332, a light separation section 333, a first light collecting element 334, and a wavelength conversion device 335 are arranged on the optical axis Ax1. Arranged on the optical axis Ax2 are a diffusive optical member 337, a second light-collecting element 336, and a light separating unit 333. The light separating unit 333 is arranged at the intersection of the optical axis Ax1 and the optical axis Ax2. The optical axis Ax2 is connected to the illumination optical axis Ax at the first lens array 341 of the uniformizing device .

[0021] The light source 331 emits light toward the diffuse transmission portion 332. The light source 331 includes a light emitting element 3311 and a substrate 3312. The light emitting element 3311 emits blue light LB. The blue light LB is excitation light that excites the phosphor of the wavelength conversion device 335. The light emitting element 3311 is, for example, a semiconductor laser that emits laser light with a peak wavelength of 455 nm. The substrate 3312 supports the light emitting element 3311. On the surface of the substrate 3312 opposite to the light emitting element 3311, a first heat receiving member 3391 exposed to the outside of the light source casing 338 is provided.

[0022] The diffuse transmission section 332 diffuses the blue light LB incident from the light source 331 to make the illuminance distribution of the blue light LB uniform. The blue light LB emitted from the diffuse transmission section 332 is incident on the light separation section 333. Examples of the diffuse transmission section 332 include a configuration having a hologram, a configuration in which a plurality of small lenses are arranged in a plane perpendicular to the optical axis, and a configuration in which the surface through which light passes is rough.

[0023] The light separating unit 333 has a function of a half mirror that transmits a portion of the blue light LB incident from the light source 331 via the diffuse transmission unit 332 and reflects the other blue light LB. That is, the light separating unit 333 transmits a first partial light, which is a portion of the blue light LB incident from the diffuse transmission unit 332, to make it incident on the first light collecting element 334, and reflects a second partial light, which is the other blue light LB, to make it incident on the second light collecting element 336. The light separating section 333 further functions as a dichroic mirror that reflects the fluorescence LY incident from the wavelength converting device 335 and transmits the blue light LB incident from the diffusing optical member 337 .

[0024] The first light collecting element 334 collects the first partial light that has passed through the light separating unit 333 onto the wavelength converter 335. In addition, the first light collecting element 334 collimates the fluorescence LY incident from the wavelength converter 335 and makes the collimated fluorescence incident on the light separating unit 333.

[0025] The wavelength converter 335 is a reflective wavelength converter that converts the wavelength of incident light, and emits the converted light in the opposite direction to the incident direction of the light. The light emitted from the wavelength converter 335 is, for example, unpolarized fluorescent light LY having a peak wavelength in the range of 500 to 700 nm, and the fluorescent light LY includes green light and red light. In this embodiment, the wavelength conversion device 335 has a wavelength conversion element 3351 containing a phosphor and a reflective substrate 3352 that supports the wavelength conversion element 3351, and a reflective layer is provided between the wavelength conversion element 3351 and the reflective substrate 3352. A second heat-receiving member 3392 exposed to the outside of the light source housing 338 is connected to the surface of the reflective substrate 3352 opposite to the wavelength conversion element 3351 in a heat-transferable manner. The configuration of the wavelength conversion device 335 is not limited to the above, and may also include a reflecting substrate 3352 on which the wavelength conversion element 3351 is arranged in a ring shape, and a driving unit (not shown) that rotates the reflecting substrate 3352 around a rotation axis along the optical axis Ax1.

[0026] The fluorescence LY emitted from the wavelength converter 335 passes through the first light collecting element 334 along the optical axis Ax1, and then enters the light separating unit 333. The fluorescence LY that has entered the light separating unit 333 is reflected by the light separating unit 333 and emitted to the outside of the light source device 33 along the optical axis Ax2.

[0027] The second light collecting element 336 collects the second partial light incident from the light separating unit 333 onto the diffusing optical member 337. The second light collecting element 336 collimates the blue light incident from the diffusing optical member 337 and causes the light to enter the light separating unit 333 along the optical axis Ax2.

[0028] The diffusing optical member 337 reflects and diffuses the blue light LB incident from the second light collecting element 336 at a diffusion angle that is substantially the same as or slightly smaller than the diffusion angle of the fluorescence LY caused by the wavelength conversion device 335. In other words, the diffusing optical member 337 reflects and diffuses the incident light without converting the wavelength of the incident light. The blue light LB reflected by the diffusing optical member 337 passes through the second light collecting element 336 and the light separating section 333, and is emitted to the outside of the light source device 33 together with the fluorescent light LY. As described above, the illumination light WL emitted to the outside of the light source device 33 is white light that is a mixture of blue light LB and fluorescence LY containing green light and red light. The illumination light WL is emitted from the light source device 33 to the uniformizing device 34 through the passage 3381 that the light source housing 338 has.

[0029] The light source housing 338 accommodates the light source 331, the diffuse transmission section 332, the light separation section 333, the first light collecting element 334, the wavelength conversion device 335, the second light collecting element 336, and the diffusion optical member 337. The light source housing 338 has a passage opening 3381 through which the illumination light WL passes.

[0030] The heat receiving member 339 receives heat from a cooling target among the components of the light source device 33. The heat receiving member 339 includes a first heat receiving member 3391, a second heat receiving member 3392, and a heat pipe 3393 not shown in FIG. The first heat receiving member 3391 is connected to the substrate 3312 of the light source 331 so as to be capable of transferring heat, and receives heat from the light emitting element 3311 via the substrate 3312. That is, the object to be cooled by the first heat receiving member 3391 is the light source 331. The second heat receiving member 3392 is connected to the reflecting substrate 3352 of the wavelength converter 335 so as to be heat transferable, and receives heat from the wavelength conversion element 3351 via the reflecting substrate 3352. That is, the target to be cooled by the second heat receiving member 3392 is the wavelength converter 335. The heat pipe 3393 is connected to the first heat receiving member 3391 and the second heat receiving member 3392 so as to be capable of transferring heat therebetween, and transfers heat from the second heat receiving member 3392 to the first heat receiving member 3391 .

[0031] [Configuration of heat absorption device] FIG. 4 is a plan view showing the configuration of the heat absorption device 40. As shown in FIG. The heat absorption device 40 absorbs heat from the object to be cooled inside the exterior housing 31 and transfers the absorbed heat to the heat transport device 6 (described later), thereby cooling the object to be cooled inside the projector 3. More specifically, the heat absorption device 40 transfers the heat to the refrigerant circulated by the heat transport device 6, thereby transporting the heat absorbed from the object to be cooled to the outside of the exterior housing 31, thereby cooling the object to be cooled.

[0032] The heat absorbing device 40 includes a cold plate 41 , a panel frame 42 , a heat absorbing radiator 43 , a circulation fan 44 and piping 45 . The cold plate 41 is heat-transferably connected to the first heat-receiving member 3391. The cold plate 41 transfers heat transferred from the first heat-receiving member 3391 to a refrigerant supplied by a first pipe 451 of the pipes 45, thereby cooling the light source 331 and the wavelength converter 335 that are heat-transferably connected to the first heat-receiving member 3391.

[0033] The panel frame 42 is provided for each of the three light modulation devices 373. That is, the heat absorption device 40 has a panel frame 42R provided for the light modulation device 373R, a panel frame 42G provided for the light modulation device 373G, and a panel frame 42B provided for the light modulation device 373B. Each panel frame 42 is configured to allow the refrigerant supplied by the second pipe 452 of the pipes 45 to flow through it, and cools the corresponding optical modulator 373 by transferring heat received from the corresponding optical modulator 373 to the refrigerant. In this embodiment, the three panel frames 42 are connected by the second pipe 452 so that the refrigerant flows through the panel frame 42R, the panel frame 42G, and the panel frame 42B in this order.

[0034] The heat-absorbing radiator 43 transfers the heat received from the gas in the exterior housing 31 to the refrigerant supplied by the third pipe 453 of the pipe 45, thereby cooling the gas in the exterior housing 31. The circulation fan 44 circulates the gas cooled by the heat-absorbing radiator 43 within the exterior housing 31 , thereby cooling the power supply device and control device (not shown) that are arranged within the exterior housing 31 .

[0035] The piping 45 supplies the refrigerant supplied to the first connection part 317 by the heat transport device 6 to the cold plate 41, the panel frame 42, and the heat-absorbing radiator 43, and guides the refrigerant that has circulated through the cold plate 41, the panel frame 42, and the heat-absorbing radiator 43 to the second connection part 318. The piping 45 has a first piping 451, a second piping 452, and a third piping 453. The first pipe 451 is a pipe that connects the first connection part 317, the cold plate 41, and the second connection part 318 so that the refrigerant can flow through them. Of the refrigerant supplied to the first connection part 317, a portion of the refrigerant is supplied to the cold plate 41 via the first pipe 451, and the refrigerant that has circulated through the cold plate 41 is discharged to the second connection part 318 via the first pipe 451.

[0036] The second pipe 452 is a pipe that connects the first connection portion 317, the three panel frames 42, and the second connection portion 318 so that the refrigerant can flow through them. Of the refrigerant supplied to the first connection portion 317, another portion of the refrigerant flows through the panel frame 42R, the panel frame 42G, and the panel frame 42B in that order via the second pipe 452, and the refrigerant to which heat has been transferred from each of the panel frames 42R, 42G, and 42B is discharged to the second connection portion 318 via the second pipe 452. The third pipe 453 is a pipe that connects the first connection part 317, the heat-absorbing radiator 43, and the second connection part 318 so that the refrigerant can flow through them. Of the refrigerant supplied to the first connection part 317, the remaining refrigerant is supplied to the heat-absorbing radiator 43 via the first pipe 451, and the refrigerant from which heat has been transferred by the heat-absorbing radiator 43 is discharged to the second connection part 318 via the third pipe 453. The refrigerant discharged to the second connection portion 318 flows from the branch discharge path 64 of the heat transport device 6 through the second transport path 63 and then flows to the heat exchange device 71 of the heat dissipation device 7 .

[0037] [Cooling system configuration] The cooling device 5 cools the multiple projectors 3 that make up the projector group 2. More specifically, the cooling device 5 is a cooling device that cools the cooling targets of each of the multiple projectors 3, and is provided outside the exterior housings 31 of each of the multiple projectors 3. In other words, the cooling device 5 is a cooling system that collectively cools the cooling targets of each of the projectors 3. As described above, the cooling device 5 includes the heat transport device 6 and the heat dissipation device 7.

[0038] [Configuration of the heat transport device] 1, the heat transport device 6 transports heat absorbed by the heat absorption device 40 from the light source 331, the wavelength conversion device 335, the light modulation device 373, and the gas inside the exterior housing 31 to the heat dissipation device 7. More specifically, the heat transport device 6 connects each of the heat absorption devices 40 provided in the multiple projectors 3 to the heat exchange device 71 so that heat can be transferred via a refrigerant. The heat transport device 6 includes a first transport path 61 , a second transport path 63 , and a pump 65 .

[0039] The first transport path 61 is a circulation pipe through which a refrigerant such as ethylene glycol can flow. The first transport path 61 connects the heat exchanger 71 of the heat dissipation device 7 and the first connection unit 317 of each projector 3, and supplies the refrigerant sent out from the heat exchanger 71 by the pump 65 to the first connection unit 317 of each projector 3. In other words, the first transport path 61 circulates the refrigerant from the heat exchanger 71 to the heat absorption device 40 of each projector 3. The first transport path 61 has a plurality of branched outlet paths 62 branching off from the first transport path 61. Each of the plurality of branched outlet paths 62 is a circulation pipe through which the refrigerant can flow, and is connected to the first connection unit 317 of each projector 3. In other words, the first transport path 61 has branched outlet paths 62 corresponding to the number of projectors 3 included in the projection system 1. The refrigerant that has flowed through the first transport path 61 is diverted to each of the plurality of branched outlet paths 62 and supplied to the first connection unit 317 of the corresponding projector 3.

[0040] The second transport path 63 is a circulation pipe through which the refrigerant can flow. The second transport path 63 connects the second connection portion 318 of each projector 3 to the heat exchanger 71, and causes the refrigerant discharged from the second connection portion 318 of each projector 3 to flow through the heat exchanger 71. As a result, heat absorbed from the object to be cooled by the heat absorption device 40 of each projector 3 is transported to the heat exchanger 71. In other words, the second transport path 63 causes the refrigerant to flow from the heat absorption device 40 of each projector 3 to the heat exchanger 71. The second transport path 63 has a plurality of branch discharge paths 64 branching off from the second transport path 63. Each of the plurality of branch discharge paths 64 is a circulation pipe through which the refrigerant can flow, and is connected to the second connection portion 318 of each projector 3. In other words, the second transport path 63 has branch discharge paths 64 corresponding to the number of projectors 3 included in the projection system 1. The refrigerant that has flowed through each branch discharge path 64 then flows through the second transport path 63 and into the heat exchanger 71.

[0041] The pump 65 is provided in at least one of the first transport path 61 and the second transport path 63 , and pumps the refrigerant stored in the heat exchanger 71 to the first transport path 61 . In this embodiment, the pump 65 is provided in the first transport path 61 between the heat exchanger 71 and the branched discharge path 62 that is closest to the heat exchanger 71 among the multiple branched discharge paths 62. The pump 65 pressure-transfers the refrigerant stored in the heat exchanger 71 to the first transport path 61, and thereby supplies the refrigerant to the first connection portion 317 of each projector 3 via the first transport path 61, and also circulates the refrigerant discharged from the second connection portion 318 to the second transport path 63 to the heat exchanger 71.

[0042] [Configuration of heat dissipation device] The heat dissipation device 7 dissipates the heat transported by the heat transport device 6. The heat dissipation device 7 is disposed outside the exterior housing 31 of each of the multiple projectors 3. In detail, the heat dissipation device 7 dissipates the heat of the object to be cooled of each projector 3, which has been absorbed by the heat absorption device 40 and transported by the heat transport device 6, outside the exterior housing 31 of each projector 3, thereby cooling each projector 3. In other words, the heat dissipation device 7 is a temperature adjustment device that adjusts the temperature of the object to be temperature adjusted of the projector 3. Specifically, the heat dissipation device 7 circulates a working fluid such as water that changes phase between liquid and gas to adjust the temperature of a refrigerant supplied to each projector 3, and thereby adjusts the temperature of a temperature-adjusted object of each projector 3. In this embodiment, the heat dissipation device 7 cools the cooling object, which is a temperature-adjusted object of each projector 3, mainly by cooling the refrigerant. The heat dissipation device 7 includes a heat exchanger 71, a compression section 72, a condensation section 73, an expansion section 74, a plurality of connection pipes 75, and a cooling fan 76.

[0043] One heat exchanger 71 is provided in the heat dissipation device 7. That is, the heat dissipation device 7 includes one heat exchanger 71. The heat exchanger 71 cools the refrigerant by exchanging heat between the working fluid circulating from the expansion section 74 and the refrigerant circulated by the heat transport device 6. That is, the heat exchanger 71 cools the refrigerant by the low-temperature working fluid circulating from the expansion section 74. The heat exchanger 71 has a housing 711 and an evaporation section 712. The housing 711 functions as a storage section that stores the refrigerant. The refrigerant in the housing 711 is sucked by the pump 65 and sent to the first transport path 61. The refrigerant that has circulated through the second transport path 63 is stored in the housing 711. The evaporation section 712 is disposed so as to be able to come into contact with the refrigerant inside the housing 711. The evaporation section 712 evaporates the liquid-phase working fluid flowing from the expansion section 74 using heat transferred from the refrigerant, changing it into gas-phase working fluid, and discharges the changed gas-phase working fluid to the compression section 72. This cools the refrigerant that cools the object to be cooled in each projector 3.

[0044] The compression section 72 compresses the gas-phase working fluid. That is, the compression section 72 increases the temperature and pressure of the gas-phase working fluid by compressing the gas-phase working fluid that flows in from the evaporation section 712 in the heat exchanger 71. The gas-phase working fluid that has been increased in temperature and pressure by the compression section 72 flows into the condensation section 73. The condenser 73 is connected to the compressor 72 via a connecting pipe 75. The condenser 73 condenses the gas-phase working fluid compressed by the compressor 72, i.e., the gas-phase working fluid that has been heated and pressurized, into a liquid-phase working fluid. Specifically, the condenser 73 condenses the gas-phase working fluid into a high-pressure liquid-phase working fluid by exchanging heat between the compressed gas-phase working fluid and a cooling gas circulated through the condenser 73 by a cooling fan 76.

[0045] The expansion section 74 is a pressure reducer and is connected to the condensation section 73. The expansion section 74 reduces the pressure of the liquid-phase working fluid condensed by the condensation section 73, changing it into a working fluid having a mixed phase of liquid and gas. That is, the expansion section 74 lowers the temperature of the working fluid. The expansion section 74 discharges the working fluid having a mixed phase of liquid and gas to the evaporation section 712. The expansion section 74 can be configured, for example, by an expansion valve, more specifically, an electronic expansion valve, that can control the evaporation temperature of the liquid-phase working fluid, or by a capillary tube.

[0046] The plurality of connection pipes 75 connect an evaporator section 712, a compressor section 72, a condenser section 73, and an expansion section 74 of the heat exchanger 71, which will be described later, in a ring shape. The plurality of connection pipes 75 include a first connection pipe 751, a second connection pipe 752, a third connection pipe 753, and a fourth connection pipe 754. Each of the connection pipes 751 to 754 is a tubular member through which the working fluid can flow. The first connection pipe 751 connects the evaporation section 712 and the compression section 72 together. The second connection pipe 752 connects the compression section 72 and the condensation section 73 together. The third connection pipe 753 connects the condensation section 73 and the expansion section 74 together. The fourth connection pipe 754 connects the expansion section 74 and the evaporation section 712 . As described above, the heat dissipation device 7 has a circulation path for the working fluid that flows through the evaporation section 712, the first connection pipe 751, the compression section 72, the second connection pipe 752, the condensation section 73, the third connection pipe 753, the expansion section 74, and the fourth connection pipe 754 in this order, and then flows back into the evaporation section 712. The circulation path adjusts the temperature of the refrigerant circulated by the heat transport device 6.

[0047] [Screen configuration] FIG. 5 is a schematic diagram showing the configuration of the screen 8 and the arrangement of the projector 3 relative to the screen 8. As shown in FIG. 5, the screen 8 has an incident surface 81 on which the image light projected from each projector 3 is incident, and an exit surface 82, which is the surface opposite to the incident surface 81 and from which the image light is emitted at a predetermined viewing angle θva. The screen 8 guides the image light incident on the incident surface 81 to a viewpoint set on the opposite side of the screen 8 from the projector 3. More specifically, viewpoints are set on the screen 8 according to the number and positions of the projectors, and the screen 8 emits the image light projected from the projectors 3 toward a viewpoint located on the opposite side of the center of the screen 8 from the projectors 3. Specifically, when multiple projectors 3 are arranged at approximately equal intervals along an arc centered at the center 8HC in the horizontal direction of the screen 8, the screen 8 converges and emits the image light incident on the incident surface 81 to a viewpoint located on the opposite side of the center 8HC from the projectors 3.

[0048] For example, when viewed from a position facing the entrance surface 81, the image light of the projector 3A located at the rightmost position among the multiple projectors 3 is emitted by the screen 8 toward a viewpoint VP1 located on the opposite side of the center 8HC from the projector 3A among the multiple viewpoints. The viewpoint VP1 is the viewpoint located at the rightmost position among the multiple viewpoints when viewed from a position facing the exit surface 82. When viewed from a position facing the entrance surface 81, the image light of projector 3B, which is located to the left of projector 3A among the multiple projectors 3, is emitted by the screen 8 toward viewpoint VP2, which is located on the opposite side of the center 8HC from projector 3B among the multiple viewpoints. Viewpoint VP2 is a viewpoint located to the left of viewpoint VP1 when viewed from a position facing the exit surface 82. When viewed from a position facing the entrance surface 81, the image light from the projector 3C, which is located on the leftmost side of the multiple projectors 3, is emitted by the screen 8 toward a viewpoint VP3, which is located on the opposite side of the center 8HC from the projector 3C, among the multiple viewpoints. When viewed from a position facing the exit surface 82, the viewpoint VP3 is the viewpoint located on the leftmost side of the multiple viewpoints.

[0049] In this way, the image light projected from each projector 3 is emitted toward a specific viewpoint, so that, for example, if the observer's right eye is located at viewpoint VP1 and the left eye is located at viewpoint VP2, the image based on the image light of projector 3A will be seen with the right eye, and the image based on the image light of projector 3B will be seen with the left eye. As a result, the projector 3A projects an image for the right eye, the projector 3B projects an image for the left eye, and the right eye image and the left eye image are parallax images, allowing the viewer to view a stereoscopic image. Note that the images based on the image light projected by each projector 3 do not necessarily have to be parallax images. For example, each projector 3 may project the same image, or at least one projector 3 among the multiple projectors 3 may project an image that is different from the images projected by the other projectors 3. Furthermore, in this embodiment, the screen 8 is a holographic screen having a holographic film, but is not limited to this and may be a screen in which a plurality of lenticular lenses or cylindrical lenses are arranged.

[0050] [Projector size range] When arranging multiple projectors 3 according to a preset number of viewpoints, there are restrictions on the dimensions of the exterior housing 31 in the direction in which the multiple projectors 3 are adjacent to each other. For example, when multiple projectors 3 are arranged horizontally, if the dimension of the exterior housing 31 in the horizontal direction is relatively large, it is not possible to arrange the number of projectors 3 corresponding to the number of viewpoints. Furthermore, if the projection distance of the projectors 3 to the screen 8 is short, the distance between the projectors 3 becomes narrow. Even in such a case, if the dimension of the exterior housing 31 in the horizontal direction is relatively large, it is not possible to arrange the number of projectors 3 corresponding to the number of viewpoints.

[0051] In this regard, the inventors of the present disclosure have found that when multiple projectors 3 are arranged horizontally around the horizontal center 8HC of the screen 8, the projectors 3 can be arranged efficiently by satisfying the following equation 1 regarding the dimension PJW of the exterior housing 31 along the horizontal direction: In Equation 1, PJW is expressed in mm. TR is the throw ratio of each projector 3. Wh is the horizontal length of the screen 8, which is the projection target, and is the horizontal length of the screen to be projected onto the holographic film or diffusion film. Wh is expressed in mm. θva is the horizontal viewing angle of the image displayed on the screen 8, as shown in FIG. 5, and θva is expressed in degrees. PVh is the number of viewpoints from which the images projected onto the screen 8 from each of the multiple projectors 3 arranged horizontally can be individually viewed. In other words, PVh is the number of viewpoints set in the projection system 1 in the horizontal direction, or in other words, the number of projectors 3 in the horizontal direction that make up the projector group 2. PJW≦(2*TR*Wh*tan(θva / 2)) / PVh …(1)

[0052] By satisfying the above formula 1 for the dimension PJW along the horizontal direction of the exterior housing 31 of each projector 3, it becomes easy to arrange the number of projectors according to the number of viewpoints PVh.

[0053] FIG. 6 is a schematic diagram showing the arrangement of a plurality of projectors 3 in the direction perpendicular to the screen 8. As shown in FIG. 6, even when multiple projectors 3 are arranged at approximately equal intervals in the vertical direction along an arc centered at the center 8VC in the vertical direction of the screen 8, the screen 8 outputs the image light projected from each projector 3 and incident on the incident surface 81 toward a viewpoint located on the opposite side of the center 8VC in the vertical direction of the screen 8 from the projector 3. The vertical direction can be rephrased as the upward direction along the vertical direction. For example, when viewed from a position facing the incident surface 81, the image light of the projector 3AA, which is located at the uppermost position among the multiple projectors 3, is emitted by the screen 8 toward a viewpoint VP1A, which is located on the opposite side of the center 8VC from the projector 3AA among the multiple viewpoints. When viewed from a position facing the exit surface 82, the viewpoint VP1A is the viewpoint located at the lowermost position among the multiple viewpoints. For example, when viewed from a position facing the incident surface 81, the image light of the projector 3BA, which is located at the lowest position among the multiple projectors 3, is emitted by the screen 8 toward a viewpoint VP2A, which is located on the opposite side of the center 8VC from the projector 3BA among the multiple viewpoints. When viewed from a position facing the exit surface 82, the viewpoint VP2A is the viewpoint located at the highest position among the multiple viewpoints.

[0054] The inventors of the present disclosure have found that when multiple projectors 3 are arranged at approximately equal intervals in the vertical direction along an arc centered on a center 8VC, as shown in FIG. 6, the projectors 3 can be arranged efficiently by satisfying the following equation 2 for the dimension PJH of the exterior housing 31 along the vertical direction: In Equation 2, PJH is expressed in mm. TR is the throw ratio of each projector 3. Wv is the vertical length of the screen 8, which is the projection target, and is the vertical length of the screen to be projected onto the holographic film or diffusion film. Wv is expressed in mm. θvb is the vertical viewing angle of the image displayed on the screen 8, and θvb is expressed in degrees. PVv is the number of viewpoints from which the images projected onto the screen 8 from each of the multiple projectors 3 arranged in the vertical direction can be individually viewed. In other words, PVv is the number of viewpoints set in the projection system 1 in the vertical direction, or in other words, the number of projectors 3 constituting the projector group 2 in the vertical direction. PJH≦(2*TR*Wv*tan(θvb / 2)) / PVv …(2)

[0055] By satisfying the above formula 2 for the dimension PJH along the vertical direction of the exterior housing 31 of each projector 3, it becomes easy to arrange the number of projectors according to the number of viewpoints PVv.

[0056] [Effects of the first embodiment] The projection system 1 according to the present embodiment described above has the following advantages. The projection system 1 includes a plurality of projectors 3 arranged in a horizontal direction, a screen 8 on which an image is displayed by light projected from each of the plurality of projectors 3, and a cooling device 5 that cools the plurality of projectors 3. The screen 8 corresponds to the projection target. Each of the multiple projectors 3 includes an exterior housing 31 that configures the exterior, an image projection device 32, and a heat absorption device 40. The image projection device 32 includes a light source device 33 including a light source 331, a light modulation device 373 that modulates the light emitted from the light source 331, and a projection optical device 38 that projects the light modulated by the light modulation device 373. The heat absorption device 40 absorbs heat from an object to be cooled, which is at least one of the light source 331 and the light modulation device 373. Note that in this embodiment, the heat absorption device 40 absorbs not only the heat from the light source 331 and the light modulation device 373, but also the heat from the wavelength conversion device 335 and the heat of the gas that has cooled the power supply device and the control device.

[0057] The cooling device 5 includes a heat transport device 6 and a heat dissipation device 7 . The heat transport device 6 transports the heat absorbed by the heat absorption device 40 provided in each of the plurality of projectors 3 to the outside of the exterior housing 31. The heat dissipation device 7 dissipates the heat transported by the heat transport device 6. The heat dissipation device 7 is disposed outside the exterior housing 31 of each of the plurality of projectors 3.

[0058] With this configuration, the heat of the objects to be cooled, such as the light source 331 of each projector 3, is transported from the heat absorption device 40 inside the projector 3 by the heat transport device 6 to the heat dissipation device 7 arranged outside the exterior housing 31 of each projector 3, and is then dissipated by the heat dissipation device 7. This eliminates the need for each projector to be equipped with a large-scale cooling device for cooling the objects to be cooled. This allows each projector 3 to be made smaller, and therefore the projection system 1 to be made smaller.

[0059] In the projection system 1, the heat dissipation device 7 has one heat exchanger 71 for the multiple projectors 3. The heat transport device 6 connects each of the heat absorption devices 40 provided in the multiple projectors 3 to the heat exchanger 71 so as to be heat transferable. According to this configuration, the heat dissipation device 7 includes one heat exchanger 71, and the heat to be cooled in each projector 3 is transported to the one heat exchanger 71 by the heat transport device 6. This makes it possible to reduce the number of components in the heat dissipation device 7 and also to make the projection system 1 more compact, compared to when the heat dissipation device 7 includes multiple heat exchangers arranged outside the exterior housing 31 of each projector 3.

[0060] In the projection system 1, the heat transport device 6 transports the heat absorbed by each heat absorption device 40 provided in the multiple projectors 3 to the heat exchange device 71 by a refrigerant that circulates between the heat absorption device 40 and the heat exchange device 71. According to this configuration, the heat of the object to be cooled can be efficiently transported from the heat absorption device 40 of each projector 3 to the heat exchange device 71. Therefore, the heat of the object to be cooled can be quickly transported to the outside of the projector 3, thereby improving the cooling efficiency of the object to be cooled.

[0061] In the projection system 1 , the heat transport device 6 has a first transport path 61 and a second transport path 63 . The first transport path 61 allows the refrigerant to flow from the heat exchange device 71 to the heat absorption device 40 . The second transport path 63 allows the refrigerant to flow from the heat absorbing device 40 to the heat exchange device 71 . The exterior housing 31 of each projector 3 has a first surface 311 through which light emitted from the projection optical device 38 passes, a second surface 312 different from the first surface 311, and a first connection portion 317 and a second connection portion 318 provided on the second surface 312. In this embodiment, the second surface 312 is an outer surface on the opposite side to the first surface 311. The first connection portion 317 is connected to the branched delivery path 62 of the first transport path 61 . The second connection portion 318 is connected to the branch discharge path 64 of the second transport path 63 . According to this configuration, the first transport path 61 and the second transport path 63 are connected to the first connection portion 317 and the second connection portion 318 provided on the second surface 312, which is different from the first surface 311 through which the light emitted from the projection optical device 38 passes. This allows the first transport path 61 and the second transport path 63 to be arranged so as to avoid the optical path of the light emitted from the projection optical device 38. Furthermore, since the second surface 312 is an outer surface facing a direction intersecting the arrangement direction of the multiple projectors 3, it is possible to prevent the first transport path 61 and the second transport path 63 from interfering with the arrangement of the multiple projectors 3 along the horizontal direction. This makes it easier to arrange the multiple projectors 3.

[0062] In the projection system 1, the first connection part 317 is a joint to which the branched delivery path 62 of the first transport path 61 can be detached, and the second connection part 318 is a joint to which the branched discharge path 64 of the second transport path 63 can be detached. According to this configuration, after arranging the multiple projectors 3, the transport paths 61, 63 can be connected to the respective connection portions 317, 318. Therefore, it is possible to easily arrange the multiple projectors 3 and also to easily connect the transport paths 61, 63.

[0063] In the projection system 1 , the heat dissipation device 7 has a compression section 72 , a condensation section 73 , an expansion section 74 and an evaporation section 712 . The compressor 72 compresses the gas phase working fluid, and the condenser 73 condenses the gas phase working fluid compressed by the compressor 72 into a liquid phase working fluid. The expansion section 74 reduces the pressure of the liquid-phase working fluid condensed by the condensation section 73, changing the liquid-phase working fluid into a mixed-phase working fluid of liquid and gas phases. The evaporator 712 is provided inside the housing 711 of the heat exchanger 71. The evaporator 712 converts the working fluid flowing from the expansion unit 74 into a gas-phase working fluid using the heat of the refrigerant transported by the heat transport device 6, i.e., the heat of the object to be cooled. The evaporator 712 then discharges the gas-phase working fluid to the compressor 72. According to such a configuration, the heat transferred to the heat exchanger 71 can be effectively cooled, and therefore the object to be cooled of each projector 3 can be effectively cooled.

[0064] In the projection system 1, the screen 8 as the projection target emits image light emitted from the projector 3A that projects an image for the right eye, among the multiple projectors 3, toward a viewpoint VP1, and emits image light emitted from the projector 3B that projects an image for the left eye toward a viewpoint VP2 that is different from the viewpoint VP1. The projector 3A is an example of a first projector, and the projector 3B is an example of a second projector. The image for the right eye is an example of a first image, and the viewpoint VP1 is an example of a first viewpoint. The image for the left eye is an example of a second image, and the viewpoint VP2 is an example of a second viewpoint that is different from the first viewpoint. With this configuration, the observer can view a stereoscopic image by observing the right-eye image at viewpoint VP1 with his / her right eye and the left-eye image at viewpoint VP2 with his / her left eye. Furthermore, if the two images projected by projectors 3A and 3B are not parallax images, different images can be displayed by each projector 3 for each viewpoint. Therefore, the versatility of the projection system 1 can be improved.

[0065] In projection system 1, screen 8 comprises a holographic film. According to this configuration, it is possible to easily configure a screen 8 that can project light incident from the projector 3 to a viewpoint corresponding to the projector 3.

[0066] In the projection system 1, the PJW, which is the dimension along the horizontal direction of the exterior housing 31 of the projector 3, satisfies the above-mentioned formula 1. The unit of PJW is mm. According to such a configuration, the above formula 1 is satisfied, and it becomes easy to arrange the number of projectors 3 according to the number of viewpoints.

[0067] [Second embodiment] Next, a second embodiment of the present disclosure will be described. The projection system according to this embodiment has a similar configuration to the projection system 1 according to the first embodiment, but differs in that multiple projectors 3 are arranged in a vertical direction perpendicular to the horizontal direction. In the following explanation, parts that are the same or approximately the same as parts already explained will be assigned the same reference numerals and explanations thereof will be omitted.

[0068] [Projection system overview] The projection system according to this embodiment has the same configuration as the projection system 1 according to the first embodiment. That is, the projection system according to this embodiment includes a projector group 2 made up of a plurality of projectors 3, a cooling device 5 including a heat transport device 6 and a heat dissipation device 7, and a screen 8 as a projection target.

[0069] [Projector size range] As with the projection system 1 according to the first embodiment, when multiple projectors 3 are arranged according to a preset number of viewpoints, there are restrictions on the dimensions of the exterior housing 31 in the direction in which the multiple projectors 3 are adjacent to each other. For example, when multiple projectors 3 are arranged horizontally, if the dimensions of the exterior housing 31 in the horizontal direction are relatively large, it is not possible to arrange the number of projectors 3 corresponding to the number of viewpoints. On the other hand, if the projection distance of the projectors 3 to the screen 8 is short, the intervals between the projectors 3 become narrow, and therefore if the dimensions of the exterior housing 31 in the horizontal direction are relatively large, it is not possible to arrange the number of projectors 3 corresponding to the number of viewpoints. The same is true when multiple projectors 3 are arranged vertically.

[0070] In this regard, the inventor of the present disclosure has found that when multiple projectors 3 are arranged at approximately equal intervals in the horizontal direction along an arc centered at the horizontal center 8HC of the screen 8, the projectors 3 can be arranged efficiently by satisfying the following equation 3 for the dimension PJW of the exterior housing 31 along the horizontal direction. In Equation 3, PJW is expressed in mm. TR is the throw ratio of each projector 3. Wh is the horizontal length of the screen 8, which is the projection target, and is the horizontal length of the screen to be projected onto the holographic film or diffusion film. Wh is expressed in mm. Sh is the number of projectors 3 arranged horizontally among the multiple projectors 3. Bpju is the brightness of the light emitted from one projector 3, and Bpju is expressed in klm. However, the product of the number Sh and the brightness Bpju must be less than 90. PJW≦(2*TR*Wh*tan(Sh*Bpju*1 / 2)) / Sh …(3)

[0071] By satisfying the above formula 3, it becomes easier to arrange the multiple projectors 3 arranged along the horizontal direction without interfering with each other.

[0072] Furthermore, the inventors of the present disclosure have found that when multiple projectors 3 are arranged at approximately equal intervals in the vertical direction along an arc centered at the center 8VC in the vertical direction of the screen 8, the projectors 3 can be arranged efficiently by satisfying the following equation 4 regarding the dimension PJH of the exterior housing 31 along the vertical direction. In Equation 4, PJH is expressed in mm. TR is the throw ratio of each projector 3. Wv is the vertical length of the screen 8, which is the projection target, and is the vertical length of the screen to be projected onto the holographic film or diffusion film. Wv is expressed in mm. Sv is the number of projectors 3 arranged in the vertical direction among the multiple projectors 3. Bpju is the brightness of the light emitted from one projector 3, and Bpju is expressed in klm. However, the product of the number Sv and the brightness Bpju must be less than 90. PJH≦(2*TR*Wv*tan(Sv*Bpju*1 / 2)) / Sv …(4)

[0073] By satisfying the above formula 4, it becomes easier to arrange the multiple projectors 3 arranged along the vertical direction without interfering with each other. The projection system according to this embodiment described above can achieve the same effects as the projection system 1 according to the first embodiment.

[0074] [Modification of the embodiment] The present disclosure is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present disclosure are included in the present disclosure. In each of the above embodiments, the cooling device 5 includes one heat dissipation device 7, and the heat dissipation device 7 includes one heat exchange device 71. However, this is not limiting, and among the multiple projectors 3, multiple groups including two or more projectors 3 may be formed, and a heat dissipation device 7 may be provided in each group.

[0075] In each of the above embodiments, the heat absorption device 40 includes the cold plate 41 that transfers heat transferred from the light source 331 and the wavelength conversion device 335 to the refrigerant via the heat receiving member 339, the panel frame 42 that transfers heat transferred from each optical modulation device 373 to the refrigerant, and the heat absorption radiator 43 that transfers heat absorbed from the gas in the exterior housing 31 to the refrigerant. However, this is not limiting, and the cold plate 41 may be provided for each of the light source 331 and the wavelength conversion device 335. Furthermore, the heat absorption device 40 does not necessarily have to include all of the cold plate 41, the panel frame 42, and the heat absorption radiator 43, and at least one of the cold plate 41, the panel frame 42, and the heat absorption radiator 43 may be omitted.

[0076] In the above-described embodiments, the heat transport device 6 transports the heat absorbed from the cooling target by the heat absorption device 40 to the outside of the exterior housing 31 of each projector 3 by circulating a refrigerant. However, the present invention is not limited to this, and the configuration of the heat transport device 6 that transports the heat of the cooling target inside the projector 3 to the heat dissipation device 7 provided outside the exterior housing 31 of each projector 3 is not limited to the above. For example, the heat transport device 6 may transport the heat of the cooling target to the heat dissipation device 7 provided outside the exterior housing 31 by a heat pipe extending inside and outside the exterior housing 31.

[0077] In the above-described embodiments, the first connection portion 317 connected to the first transport path 61 of the heat transport device 6 and the second connection portion 318 connected to the second transport path 63 of the heat transport device 6 are provided on the second surface 312 of the exterior housing 31, opposite the first surface 311. However, this is not limited thereto, and the first connection portion 317 and the second connection portion 318 may be provided on an outer surface other than the second surface 312. For example, the first connection portion 317 and the second connection portion 318 may be provided on any of the third surface 313, fourth surface 314, fifth surface, and sixth surface intersecting the first surface 311. In this case, any of the third surface 313, fourth surface 314, fifth surface, and sixth surface corresponds to the second surface in the present disclosure. The first connection portion 317 and the second connection portion 318 may also be provided on the first surface 311. The first connecting portion 317 and the second connecting portion 318 may be provided on different outer surfaces. Furthermore, at least one of the first connecting portion 317 and the second connecting portion 318 does not have to be a joint that allows the transport paths 61, 63 to be detachably connected.

[0078] In each of the above embodiments, the heat dissipation device 7 includes an evaporator 712, a compressor 72, a condenser 73, and an expander 74, and circulates a working fluid that changes phase between liquid and gas to cool the refrigerant stored in the housing 711 of the heat exchanger 71. However, the configuration of the heat dissipation device 7 is not limited to this, and the configuration of the heat dissipation device 7 is not limited to the above as long as the refrigerant circulated by the heat transport device 6 can be cooled. For example, the heat dissipation device 7 may include a fan that circulates cooling air through a heat sink provided in the housing 711.

[0079] In each of the above embodiments, the screen 8 as the projection target emits image light toward a viewpoint corresponding to the position of the projector 3 that projects the image light. In other words, the screen 8 emits image light to a position corresponding to the projection angle of view from the projector 3. However, this is not the only option, and the functions of the screen 8 are not limited to those described above. Furthermore, the screen 8 is not limited to a transmissive screen, and may be a reflective screen.

[0080] In the first embodiment, the dimension PJW of the exterior housing 31 along the horizontal direction satisfies the above formula 1, and the dimension PJH of the exterior housing 31 along the vertical direction satisfies the above formula 2. In the second embodiment, the dimension PJW of the exterior housing 31 along the horizontal direction satisfies the above formula 3, and the dimension PJH of the exterior housing 31 along the vertical direction satisfies the above formula 4. However, this is not limiting, and the dimension PJW does not necessarily have to satisfy formula 1 or formula 3, and the dimension PJH does not necessarily have to satisfy formula 2 or formula 4. In addition, when multiple projectors 3 are arranged along the horizontal direction and also along the vertical direction, the dimension PJW may satisfy the above formula 1 or formula 3, and the dimension PJH may satisfy the above formula 2 or formula 4. On the other hand, in the projection system of the present disclosure, it is sufficient that the multiple projectors 3 are arranged along at least one of the horizontal and vertical directions, and they do not necessarily have to be arranged along each of the horizontal and vertical directions. Furthermore, a projection system in which the dimension PJW satisfies the above formula 1 or 3, or a projection system in which the dimension PJH satisfies the above formula 2 or 4, does not need to include a cooling device 5, and the projector that constitutes the projection system does not need to include a heat absorption device 40.

[0081] Summary of this disclosure A summary of this disclosure is provided below. [Appendix 1] a plurality of projectors arranged along a horizontal direction; a projection unit on which an image is displayed by light projected from each of the plurality of projectors; a cooling device that cools the plurality of projectors; Equipped with Each of the plurality of projectors an exterior housing that forms the exterior; A light source and a light modulation device that modulates the light emitted from the light source; a projection optical device that projects the light modulated by the light modulation device; a heat absorption device that absorbs heat from an object to be cooled, which is at least one of the light source and the optical modulation device; Equipped with The cooling device is a heat transport device that transports the heat absorbed by the heat absorption device provided in each of the plurality of projectors to the outside of the exterior housing; a heat dissipation device that dissipates the heat transported by the heat transport device, the heat dissipation device is disposed outside the exterior housing of each of the plurality of projectors, A projection system characterized by:

[0082] With this configuration, the heat of the cooling target of each projector is transported from the heat absorption device inside the projector by the heat transport device to the heat dissipation device located outside the exterior housing of each projector, and then dissipated by the heat dissipation device. This eliminates the need for each projector to be equipped with a large-scale cooling device for cooling the cooling target. This allows each projector to be made smaller, and therefore the projection system to be made smaller.

[0083] [Appendix 2] 2. The projection system of claim 1, the heat dissipation device has one heat exchange device for the plurality of projectors, the heat transport device connects each of the heat absorption devices provided in the plurality of projectors to the heat exchange device in a heat transferable manner; A projection system characterized by: With this configuration, the heat dissipation device includes one heat exchanger, and the heat of the object to be cooled in each projector is transported to the one heat exchanger by the heat transport device. This allows for a reduction in the number of components in the heat dissipation device and a reduction in the size of the projection system compared to when the heat dissipation device includes multiple heat exchangers arranged outside the exterior housings of each projector.

[0084] [Appendix 3] 3. The projection system of claim 2, the heat transport device transports the heat absorbed by each of the heat absorption devices provided in the plurality of projectors to the heat exchange device by a refrigerant circulating between the heat absorption device and the heat exchange device; A projection system characterized by: With this configuration, the heat of the object to be cooled can be efficiently transported from the heat absorption device of each projector to the heat exchange device. Therefore, the heat of the object to be cooled can be quickly transported to the outside of the projector, thereby improving the cooling efficiency of the object to be cooled.

[0085] [Appendix 4] 4. The projection system of claim 3, The heat transport device is a first transport path for circulating the refrigerant from the heat exchange device to the heat absorption device; a second transport path for circulating the refrigerant from the heat absorption device to the heat exchange device; and The exterior housing is a first surface through which light emitted from the projection optical device passes; a second surface different from the first surface; a first connection portion provided on the second surface and connected to the first transport path; a second connection portion provided on the second surface and connected to the second transport path; having A projection system characterized by: According to this configuration, the first transport path and the second transport path are connected to the first connection portion and the second connection portion provided on the second surface, which is different from the first surface through which the light emitted from the projection optical device passes. This allows the first transport path and the second transport path to be arranged so as to avoid the optical path of the light emitted from the projection optical device. Furthermore, if the second surface is an outer surface facing a direction intersecting the arrangement direction of the multiple projectors, i.e., if the second surface is a surface opposite to the first surface, or if the second surface is a surface intersecting the vertical direction that intersects the horizontal direction, the first transport path and the second transport path can be prevented from interfering with the arrangement of the multiple projectors. This makes it easier to arrange the multiple projectors.

[0086] [Appendix 5] 5. The projection system of claim 4, the first connection portion is a joint to which the first transport path is detachable, The second connection portion is a joint to which the second transport path is detachable. A projection system characterized by: According to this configuration, after the multiple projectors are arranged, the transport paths can be connected to the respective connection sections. Therefore, it is possible to easily arrange the multiple projectors and also to easily connect the transport paths.

[0087] [Appendix 6] 6. The projection system of claim 3, further comprising: The heat dissipation device is a compression section that compresses the gas phase working fluid; a condensation unit that condenses the gas-phase working fluid compressed by the compression unit into the liquid-phase working fluid; an expansion section that reduces the pressure of the liquid-phase working fluid condensed by the condensation section to change the liquid-phase working fluid into the working fluid having a mixed phase of liquid and gas; an evaporator section provided inside the heat exchanger, which converts the working fluid flowing from the expansion section into a gas phase working fluid by using the heat of the object to be cooled transported by the heat transport device, and discharges the converted gas phase working fluid to the compressor section; Equipped with A projection system characterized by: According to this configuration, the heat transferred to the heat exchange device can be effectively cooled, so that the object to be cooled in each projector can be effectively cooled.

[0088] [Appendix 7] 7. The projection system of claim 1, further comprising: the projected portion emits image light emitted from a first projector that projects a first image, among the plurality of projectors, toward a first viewpoint, and emits image light emitted from a second projector that projects a second image, toward a second viewpoint different from the first viewpoint; A projection system characterized by: According to this configuration, when a first image formed by image light emitted to a first viewpoint and a second image formed by image light emitted to a second viewpoint are parallax images, the observer can view a stereoscopic image by observing the first image at the first viewpoint with one of the right and left eyes and observing the second image at the second viewpoint with the other eye. Furthermore, if the first image and the second image are not parallax images, different images can be displayed for each viewpoint by a plurality of projectors. Therefore, the versatility of the projection system can be improved.

[0089] [Appendix 8] 8. The projection system of claim 7, The projection portion includes a holographic film. A projection system characterized by: According to this configuration, as described above, light incident from a projector can be emitted to a viewpoint corresponding to the projector.

[0090] [Appendix 9] 9. The projection system of any one of claims 1 to 8, The throw ratio of one of the plurality of projectors is defined as TR, The length of the projection portion along the horizontal direction is defined as Wh, The viewing angle of the image along the horizontal direction is θva, If the number of viewpoints at which the images projected onto the projection target from each of the plurality of projectors arranged in the horizontal direction can be individually viewed is PVh, then: The PJW, which is the dimension along the horizontal direction of the exterior housing of the one projector, satisfies Expression 5: A projection system characterized by: PJW≦(2*TR*Wh*tan(θva / 2)) / PVh …(5) With this configuration, the above formula 1 is satisfied, making it easier to arrange the number of projectors according to the number of viewpoints. [Explanation of symbols]

[0091] 1...projection system, 2...projector group, 3...projector, 31...exterior housing, 311...first surface, 312...second surface, 32...image projection device, 331...light source, 335...wavelength conversion device, 373...light modulation device, 38...projection optical device, 40...heat absorption device, 41...cold plate, 42...panel frame, 43...heat absorption radiator, 44...circulation fan, 45...piping, 5...cooling device, 6...heat transport device, 61...first transport Feed path, 62...branched feed path, 63...second transport path, 64...branched discharge path, 65...pump, 7...heat dissipation device, 71...heat exchange device, 711...housing, 712...evaporation section, 72...compression section, 73...condensation section, 74...expansion section, 75...connecting pipe, 751...first connecting pipe, 752...second connecting pipe, 753...third connecting pipe, 754...fourth connecting pipe, 76...cooling fan, 8...screen (projected section), 81...incident surface, 82...exiting surface.

Claims

1. a plurality of projectors arranged along a horizontal direction; a projection unit on which an image is displayed by light projected from each of the plurality of projectors; a cooling device that cools the plurality of projectors; Equipped with Each of the plurality of projectors an exterior housing that forms the exterior; A light source and a light modulation device that modulates the light emitted from the light source; a projection optical device that projects the light modulated by the light modulation device; a heat absorption device that absorbs heat from an object to be cooled, which is at least one of the light source and the optical modulation device; Equipped with The cooling device is a heat transport device that transports the heat absorbed by the heat absorption device provided in each of the plurality of projectors to the outside of the exterior housing; a heat dissipation device that dissipates the heat transported by the heat transport device, the heat dissipation device is disposed outside the exterior housing of each of the plurality of projectors, A projection system characterized by:

2. 2. The projection system of claim 1, the heat dissipation device has one heat exchange device for the plurality of projectors, the heat transport device connects each of the heat absorption devices provided in the plurality of projectors to the heat exchange device in a heat transferable manner; A projection system characterized by:

3. 3. The projection system of claim 2, the heat transport device transports the heat absorbed by each of the heat absorption devices provided in the plurality of projectors to the heat exchange device by a refrigerant circulating between the heat absorption device and the heat exchange device; A projection system characterized by:

4. 4. The projection system of claim 3, The heat transport device is a first transport path for circulating the refrigerant from the heat exchange device to the heat absorption device; a second transport path for circulating the refrigerant from the heat absorption device to the heat exchange device; and The exterior housing is a first surface through which light emitted from the projection optical device passes; a second surface different from the first surface; a first connection portion provided on the second surface and connected to the first transport path; a second connection portion provided on the second surface and connected to the second transport path; having A projection system characterized by:

5. 5. The projection system of claim 4, the first connection portion is a joint to which the first transport path is detachable, The second connection portion is a joint to which the second transport path is detachable. A projection system characterized by:

6. 4. The projection system of claim 3, The heat dissipation device is a compression section that compresses the gas phase working fluid; a condensation unit that condenses the gas phase working fluid compressed by the compression unit into the liquid phase working fluid; an expansion section that reduces the pressure of the liquid-phase working fluid condensed by the condensation section to change the liquid-phase working fluid into the working fluid having a mixed phase of liquid and gas; an evaporator section provided inside the heat exchanger, which converts the working fluid flowing from the expansion section into a gas phase working fluid by using the heat of the object to be cooled transported by the heat transport device, and discharges the converted gas phase working fluid to the compressor section; Equipped with A projection system characterized by:

7. 7. The projection system according to claim 1, the projected portion emits image light emitted from a first projector that projects a first image, among the plurality of projectors, toward a first viewpoint, and emits image light emitted from a second projector that projects a second image, toward a second viewpoint different from the first viewpoint; A projection system characterized by:

8. 8. The projection system of claim 7, The projection portion includes a holographic film. A projection system characterized by:

9. 7. The projection system according to claim 1, The throw ratio of one projector among the plurality of projectors is defined as TR, The length of the projection portion along the horizontal direction is Wh, The viewing angle of the image along the horizontal direction is θva, When the number of viewpoints at which the images projected onto the projection unit from each of the plurality of projectors arranged in the horizontal direction can be individually viewed is denoted by PVh, The PJW, which is the dimension along the horizontal direction of the exterior housing of the one projector, satisfies Expression 1: A projection system characterized by: PJW≦(2*TR*Wh*tan(θva / 2)) / PVh…(1)

Images