projector

Abstract

We provide a projector that can reduce the area of ​​its base. [Solution] The projector comprises a projection light generation device, a cooling fan, a heat dissipation member, and a housing. The projection light generation device includes a light source device having a first light source that emits first light, a second light source that emits second light, and a third light source that emits third light; an optical modulation device having a first optical modulation element, a second optical modulation element, and a third optical modulation element; and a photosynthesis device that synthesizes the first light, second light, and third light modulated by the optical modulation device. The cooling fan is positioned to overlap the projection light generation device and the heat dissipation member when viewed from a first direction perpendicular to the plane containing the optical axes of the first light, second light, and third light. The projection light generation device and the heat dissipation member are sandwiched between the cooling fan in the first direction, and the cooling fan generates an airflow that flows in one of the first direction and the direction opposite to the first direction.

Description

Technical Field

[0001] The present disclosure relates to a projector.

Background Art

[0002] Conventionally, a projector including a light source device, a light modulation device, a color synthesis optical device, and a projection lens has been known (see, for example, Patent Document 1). In the projector described in Patent Document 1, the light source device has a first blue LED (Light Emitting Diode) element, a second blue LED element, and a green LED element. The blue light emitted from the first blue LED is converted into red light by a red phosphor. The light modulation device is composed of a light modulation device that modulates the converted red light, a light modulation device that modulates the blue light emitted from the second blue LED element, and a light modulation device that modulates the green light emitted from the green LED element. The color synthesis optical device synthesizes the respective color lights modulated by the light modulation device to form a color image, and the projection lens projects the formed color image.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the projector described in Patent Document 1, the first blue LED element, the second blue LED element, and the green LED element are arranged dispersedly. Therefore, when heat sinks and fans are provided according to each LED element to cool each LED element individually, there is a problem that the footprint of the product, that is, the area of the bottom surface of the product, tends to be large. For this reason, a configuration that can reduce the area of the bottom surface has been desired. [Means for solving the problem]

[0005] A projector according to one aspect of the present disclosure comprises: a projection light generating device that generates projected light; a cooling fan that generates an airflow to which heat generated by the projection light generating device is transferred; a heat dissipation member that dissipates the transferred heat into the airflow; and a housing that houses the projection light generating device, the cooling fan, and the heat dissipation member, wherein the projection light generating device comprises: a light source device having a first light source that emits first light, a second light source that emits second light, and a third light source that emits third light; a first light modulation element that modulates the first light, a second light modulation element that modulates the second light, and the third light The optical modulation device has a third optical modulation element that modulates the first light, the second light, and the third light modulated by the optical modulation device, and the cooling fan is positioned to overlap the projection light generation device and the heat dissipation member when viewed from a first direction perpendicular to the plane containing the optical axes of the first light, the second light, and the third light, the projection light generation device and the heat dissipation member sandwich the cooling fan in the first direction, and the cooling fan generates the airflow that flows in one of the first direction and the direction opposite to the first direction. [Brief explanation of the drawing]

[0006] [Figure 1] A perspective view showing the appearance of the projector in the first embodiment. [Figure 2] A perspective view showing part of the internal structure of the projector in the first embodiment. [Figure 3] A perspective view showing the projection light generation device and cooling device in the first embodiment. [Figure 4] A perspective view showing the projection light generation device and cooling device in the first embodiment. [Figure 5] A cross-sectional view showing the injection section in the first embodiment. [Figure 6] A plan view showing the projection light generation device in the first embodiment. [Figure 7] A perspective view showing the cooling fan, heat dissipation member, and rectifier plate in the first embodiment. [Figure 8] A diagram showing the positional relationship between the optical modulation element and the flow section in the first embodiment. [Figure 9] A diagram showing the flow path of the cooling gas within the internal housing in the first embodiment. [Figure 10] A block diagram showing the configuration of the control device in the first embodiment. [Figure 11] A perspective view showing the projector in the second embodiment. [Figure 12] A block diagram showing the configuration of the control device included in the projector in the third embodiment. [Modes for carrying out the invention]

[0007] [First Embodiment] The first embodiment of this disclosure will be described below with reference to the drawings. [Projector Configuration] Figure 1 is a perspective view showing the external appearance of projector 1A according to this embodiment. As shown in Figure 1, the projector 1A according to this embodiment includes an outer casing 2. The outer casing 2 constitutes the exterior of the projector 1A. In this embodiment, the outer casing 2 corresponds to the casing that houses the internal casing 3, the projection light generation device 4, and the cooling device 5, which will be described later. The outer casing 2 is configured in a roughly rectangular parallelepiped shape, having a front 21, a rear 22, a top 23, a bottom 24, a right side 25, and a left side 26. The front 21 exposes a portion of the projection lens 47 of the projection light generation device 4 and has a passage opening 211 through which the projection light projected by the projection lens 47 passes. The space between the inner edge of the passage opening 211 and the projection lens 47 is sealed by a sealing member. Although not shown in the diagram, the outer casing 2 has an inlet for introducing outside air into the outer casing 2 as a cooling gas, and an outlet for discharging the cooling gas inside the outer casing 2 to the outside of the outer casing 2.

[0008] In the following description, three mutually perpendicular directions are defined as the +X direction, the +Y direction, and the +Z direction. The +Z direction is the direction from the back surface 22 toward the front surface 21, the +X direction is the direction from the left side surface 26 toward the right side surface 25, and the +Y direction is the direction from the bottom surface 24 toward the top surface 23. The +Z direction is the direction in which the projection light generating device 4 described later projects the projection light when viewed from the +Y direction. The direction opposite to the +X direction is defined as the -X direction, the direction opposite to the +Y direction is defined as the -Y direction, and the direction opposite to the +Z direction is defined as the -Z direction.

[0009] [Internal Structure of the Projector] FIG. 2 is a perspective view showing the projector 1A with the exterior housing 2 removed, and is a perspective view showing a part of the internal structure of the projector 1A. That is, FIG. 2 is a perspective view showing the internal housing 3. FIG. 3 is a perspective view of the projection light generating device 4 and the cooling device 5 housed in the internal housing 3 viewed from the light emitting side of the projection light, and FIG. 4 is a perspective view of the projection light generating device 4 and the cooling device 5 viewed from the side opposite to the light emitting side of the projection light. The projector 1A includes the internal housing 3 shown in FIG. 2, and also includes the projection light generating device 4 and the cooling device 5 shown in FIGS. 3 and 4. In addition, although details will be described later, the projector 1A includes a control device 6A that controls the operation of the projector 1A.

[0010] [Configuration of the Internal Housing] The internal housing 3 shown in FIG. 2 corresponds to the housing in the present embodiment, and is a substantially rectangular parallelepiped housing that houses the projection light generating device 4 and the cooling device 5 inside. The internal housing 3 is a sealed housing, and is configured such that dust hardly enters inside. The internal housing 3 has a front surface 31, a back surface 32, a top surface 33, a bottom surface 34, a right side surface 35, and a left side surface 36.

[0011] The front surface 31 and the back surface 32 are surfaces facing opposite to each other. The front surface 31 faces the +Z direction, and the back surface 32 faces the -Z direction. The front surface 31 has an opening 311 and a sealing member 312. The opening 311 is an opening through which the projected light projected by a projection lens 47 described later passes. In the present embodiment, a part of the projection lens 47 is inserted through the opening 311. The sealing member 312 seals the opening 311 in a state where a part of the lens barrel 472 of the projection lens 47 is disposed inside the opening 311. The top surface 33 and the bottom surface 34 are surfaces facing opposite to each other. The top surface 33 faces the +Y direction, and the bottom surface 34 faces the -Y direction. The right side surface 35 and the left side surface 36 are surfaces facing opposite to each other. The right side surface 35 faces the +X direction, and the left side surface 36 faces the -X direction.

[0012] FIG. 5 is a cross-sectional view showing the injection part 37. The internal housing 3 is filled with a gas having a higher thermal conductivity than that of air. Examples of such a gas include helium gas. As shown in FIG. 5, the internal housing 3 has an injection part 37 for injecting the gas. The injection part 37 is provided on the intake side of a cooling fan 51 (to be described later) of the cooling device 5 in the internal housing 3. In the present embodiment, since the cooling fan 51 sends out the cooling gas in the +Y direction, the injection part 37 is provided in a part of the internal housing 3 in the -Y direction with respect to the cooling fan 51. Hereinafter, the injection part 37 will be described as being disposed in a part in the -Y direction with respect to the cooling fan 51 on the back surface 32.

[0013] The injection part 37 has an injection hole 371, a cushion 372, a diffusion part 373, and a cover member 374. The injection hole 371 is a through-hole penetrating the back surface 32 and is a hole part into which a needle ND for injecting the cooling gas into the interior of the internal housing 3 is inserted. The cushion 372 is an elastic member provided on the inner surface of the back surface 32 in accordance with the injection hole 371. When a needle is inserted through the injection hole 371, it penetrates the cushion 372 in the direction of insertion of the needle ND into the injection hole 371, so that the tip of the needle ND is exposed inside the inner housing 3. This makes it possible to inject cooling gas into the inner housing 3. On the other hand, when the needle ND is withdrawn from the cushion 372, the hole in the cushion 372 opened by the needle ND is closed by the elastic force of the cushion 372.

[0014] The diffusion unit 373 is provided inside the internal housing 3 in accordance with the cushion 372. As shown by the arrow in Figure 4, the diffusion unit 373 diffuses the cooling gas injected from the tip of the needle ND, which has penetrated the cushion 372, within the internal housing 3. The cover member 374 is a component that seals the injection hole 371 and suppresses the leakage of cooling gas from inside the internal housing 3. An example of the cover member 374 is a tape that is attached to the outer surface of the internal housing 3 so as to block the injection hole 371. Although not shown in the diagram, the bottom surface 34 has a discharge section for discharging any gas already present inside the internal housing 3 to the outside of the internal housing 3 when cooling gas is injected into the internal housing 3 using the injection section 37.

[0015] When injecting cooling gas into the internal housing 3, the cooling gas is injected into the internal housing 3 via the injection port 37, while the air inside the internal housing 3 is discharged via the discharge port. The specific gravity of helium gas is lighter than that of air. Therefore, when using helium gas as a cooling gas, the helium gas injected into the internal housing 3 pushes the air inside the internal housing 3 towards the bottom surface 34. The air pushed towards the bottom surface 34 is discharged to the outside of the internal housing 3 through the discharge port provided on the bottom surface 34. As a result, the internal housing 3 is filled with helium gas. Such an internal enclosure 3 is formed of, for example, a metal with high thermal conductivity. Therefore, the heat transferred to the cooling gas is transferred to the internal enclosure 3 as the cooling gas circulates within the internal enclosure 3, and is then released to the outside of the internal enclosure 3.

[0016] [Configuration of the projection light generation device] Figure 6 is a plan view of the projection light generation device 4 as seen from the +Y direction. The projection light generation device 4 generates projection light to be projected onto a surface such as a screen, under the control of a control device. The projection light generation device 4 is housed in a sealed state within an internal housing 3. As shown in Figure 6, the projection light generation device 4 comprises a light source device 41, a reflector 42, a field lens 43, an image forming device 44, and a projection lens 47.

[0017] The light source device 41 emits light toward the optical modulation device 45 of the image forming apparatus 44, which will be described later. The light source device 41 includes a red light source 41R, a green light source 41G, and a blue light source 41B. The red light source 41R corresponds to the first light source. The red light source 41R is an LED (Light Emitting Diode) positioned to face the +X direction, and emits red light as the first light source in the +X direction toward the red light modulation element 45R. The green light source 41G corresponds to the second light source. The green light source 41G is an LED positioned to face the +Z direction and emits green light as the second light source in the +Z direction toward the green light modulation element 45G. The blue light source 41B corresponds to the third light source. The blue light source 41B is an LED positioned to face the -X direction and emits blue light as the third light source in the -X direction toward the blue light modulation element 45B. Each light source 41R, 41G, and 41B includes a light-emitting element 411 that emits light of the corresponding color, and a substrate 412 that supports the light-emitting element 411. The heat-receiving end of a heat transport member 53, which will be described later, is thermally connected to the substrate 412.

[0018] The reflector 42 guides the light emitted from the light source device 41 to the light modulator 45. The reflector 42 includes a red reflector 42R, a green reflector 42G, and a blue reflector 42B. Each reflector 42R, 42G, and 42B is formed in a truncated pyramidal shape, with the cross-sectional area increasing in the direction of propagation of the colored light. The red reflector 42R is positioned between the red light source 41R and the red light modulation element 45R in the optical path of the red light. The red reflector 42R guides the red light emitted from the red light source 41R to the red light modulation element 45R and also equalizes the illuminance of the passing red light. The green reflector 42G is positioned between the green light source 41G and the green light modulation element 45G in the optical path of the green light. The green reflector 42G guides the green light emitted from the green light source 41G to the green light modulation element 45G and also equalizes the illuminance of the green light passing through it. The blue reflector 42B is positioned between the blue light source 41B and the blue light modulation element 45B in the blue light path. The blue reflector 42B guides the blue light emitted from the blue light source 41B to the blue light modulation element 45B and also equalizes the illuminance of the blue light passing through it.

[0019] The field lens 43 parallelizes the light emitted from the reflector 42 and incident on the light modulator 45. The field lens 43 includes a red field lens 43R, a green field lens 43G, and a blue field lens 43B. The red field lens 43R parallelizes the red light emitted from the red reflector 42R and directs it into the red light modulation element 45R. The green field lens 43G parallelizes the green light emitted from the green reflector 42G and directs it into the green light modulation element 45G. The blue field lens 43B parallelizes the blue light emitted from the blue reflector 42B and directs it into the blue light modulation element 45B.

[0020] The image forming apparatus 44 modulates the light of each color emitted from the light source device 41 to form image light. The image forming apparatus 44 includes a light modulator 45 and a photosynthesis device 46. The optical modulator 45 modulates the light emitted from the light source device 41. The optical modulator 45 includes a red light modulator 45R, a green light modulator 45G, and a blue light modulator 45B. Each optical modulator 45R, 45G, and 45B modulates the incident color light and emits the modulated color light in the direction from which the color light was incident. In other words, each optical modulator 45R, 45G, and 45B is a transmissive optical modulator. The red light modulator 45R modulates the red light emitted from the opposing red light source 41R. The red light modulator 45R modulates the red light incident along the +X direction and emits the modulated red light in the +X direction. The green light modulation element 45G modulates the green light emitted from the opposing green light source 41G. The green light modulation element 45G modulates the green light incident along the +Z direction and emits the modulated green light in the +Z direction. The blue light modulator 45B modulates the blue light emitted from the opposing blue light source 41B. The blue light modulator 45B modulates the blue light incident along the -X direction and emits the modulated blue light in the -X direction. In this embodiment, each of the light modulation elements 45R, 45G, and 45B is a liquid crystal light bulb having a liquid crystal panel 451 and an incident polarizing plate 452 and an exit polarizing plate 453 that sandwich the liquid crystal panel 451.

[0021] The photosynthesis apparatus 46 synthesizes the red, green, and blue light modulated by the respective light modulation elements 45R, 45G, and 45B of the light modulation apparatus 45 to form projected light, which is image light. In this embodiment, the photosynthesis apparatus 46 is composed of a cross dichroic prism formed in a substantially rectangular parallelepiped shape. The photosynthesis apparatus 46 has a red incident surface 46R, a green incident surface 46G, a blue incident surface 46B, and an output surface 46S. The red light incident surface 46R faces the -X direction in the photosynthesis apparatus 46 and faces the red light modulator 45R. The red light incident surface 46R is the first incident surface into which red light is incident from the red light modulator 45R. The green light incident surface 46G faces the -Z direction in the photosynthesis apparatus 46 and faces the green light modulation element 45G. The green light incident surface 46G intersects with the red light incident surface 46R and is the second incident surface into which green light is incident from the green light modulation element 45G. The blue light incident surface 46B faces the +X direction in the photosynthesis apparatus 46 and faces the blue light modulation element 45B. The blue light incident surface 46B is located on the opposite side of the red light incident surface 46R in the photosynthesis apparatus 46 and is the third incident surface into which blue light is incident from the blue light modulation element 45B. The emission surface 46S faces the +Z direction in the photosynthesis apparatus 46. That is, the emission surface 46S is located on the opposite side of the green light incidence surface 46G in the photosynthesis apparatus 46. The emission surface 46S emits projected light in the +Z direction, which is a composite of the various colored lights incident on the photosynthesis apparatus 46.

[0022] The projection lens 47 is positioned so that its optical axis is aligned with the +Z direction, and projects the light emitted from the photosynthesis device 46 onto the surface to be projected. The projection lens 47 is configured as a lens assembly having a plurality of lenses 471 and a lens barrel 472 that houses the plurality of lenses 471. A portion of the lens barrel 472 passes through an opening 311 provided on the front surface 31 of the inner housing 3 along the +Z direction, and further passes through a passage opening 211 provided on the front surface 21 of the outer housing 2 along the +Z direction. As described above, the space between the inner edge of the opening 311 and the lens barrel 472 is sealed by a sealing member 312.

[0023] [Cooling system configuration] The cooling device 5 shown in Figure 3 cools the light projection generator 4. More specifically, the cooling device 5 cools the light source device 41 and the light modulation device 45 by circulating cooling gas within the internal housing 3, and also cools the light source device 41 by releasing heat transferred from the light source device 41 into the cooling gas. The cooling device 5 includes a cooling fan 51, a heat dissipation member 52, a heat transport member 53, and a rectifier plate 54.

[0024] [Cooling fan configuration] The cooling fan 51 generates an airflow to which the heat generated by the projection light generator 4 is transferred. The cooling fan 51 is positioned so as to overlap with the projection light generator 4 when viewed from the ±Y direction, which is perpendicular to the XZ plane containing the optical axes of red, green, and blue light. That is, at least a portion of the cooling fan 51 and at least a portion of the light modulator 45 and photosynthesis device 46 are positioned so as to overlap in the +Y direction or the -Y direction. The +Y direction or the -Y direction corresponds to the first direction. That is, the cooling fan 51 is positioned in the -Y direction relative to the projection light generator 4 and overlaps with the image forming device 44 when viewed from the +Y direction. More specifically, the cooling fan 51 is positioned so that its axis of rotation overlaps with the photosynthesis device 46. Such a cooling fan 51 is an axial flow fan, and in this embodiment, it draws in cooling gas located in the -Y direction relative to the cooling fan 51 and generates an airflow that circulates in the +Y direction. For this reason, the intake side portion of the cooling fan 51 in the internal housing 3 is the portion in the -Y direction relative to the cooling fan 51.

[0025] [Configuration of heat dissipation components] The heat dissipation member 52 dissipates the transferred heat into the airflow generated by the cooling fan 51. The heat dissipation member 52 is positioned to overlap with the cooling fan 51 when viewed from the ±Y direction. That is, at least a portion of the heat dissipation member 52 and at least a portion of the cooling fan 51 are positioned to overlap in the +Y direction or the -Y direction. The heat dissipation member 52 is positioned in the -Y direction relative to the cooling fan 51, and the cooling fan 51 is sandwiched between the heat dissipation member 52 and the projection light generation device 4 in the +Y direction. The heat dissipation member 52 dissipates heat transferred from the light source device 41 via the heat transport member 53 to a cooling gas circulating through the cooling fan 51. The heat dissipation member 52 includes a red heat dissipation member 52R, a green heat dissipation member 52G, and a blue heat dissipation member 52B, which are provided independently of each other. The red heat dissipation member 52R is thermally connected to the red light source 41R via the red heat transport member 53R, which will be described later, and dissipates the heat transferred from the red light source 41R. The green heat dissipation member 52G is thermally connected to the green light source 41G via the green heat transport member 53G described later, and dissipates the heat transferred from the green light source 41G. The blue heat dissipation member 52B is thermally connected to the blue light source 41B via the blue heat transport member 53B, which will be described later, and dissipates the heat transferred from the blue light source 41B. Each of the heat dissipation members 52R, 52G, and 52B is a heat sink with multiple fins arranged along the +Z direction, perpendicular to the +Z direction. The cooling gas flowing from the cooling fan 51 in the -Y direction can flow along each of the heat dissipation members 52R, 52G, and 52B in the -Y direction.

[0026] In this embodiment, each heat dissipation member 52R, 52G, and 52B is formed in a substantially rectangular parallelepiped shape that is long in the +Z direction. In order to shorten the distance from each light source 41R, 41G, and 41B, i.e., the length of the heat transport member 53, the red heat dissipation member 52R is positioned most towards the -X direction, the blue heat dissipation member 52B is positioned most towards the +X direction, and the green heat dissipation member 52G is positioned between the red heat dissipation member 52R and the blue heat dissipation member 52B. Furthermore, the volumes of the heat dissipation members 52R, 52G, and 52B are the same, and the surface areas of the heat dissipation members 52R, 52G, and 52B are the same. However, this is not limited to this, and the volume and surface area of ​​one or two of the heat dissipation members 52R, 52G, and 52B may differ from the volume and surface area of ​​the other heat dissipation members. For example, the volume and surface area of ​​the red heat dissipation member 52R may be larger than the volume and surface area of ​​the heat dissipation member 52G, and may also be larger than the volume and surface area of ​​the blue heat dissipation member 52B.

[0027] [Configuration of heat transport components] The heat transport member 53 connects the light source device 41 and the heat dissipation member 52, and transports the heat generated in the light source device 41 to the heat dissipation member 52. The heat transport member 53 includes a heat transport member 53R for red light, a heat transport member 53G for green light, and a heat transport member 53B for blue light. Each heat transport member 53R, 53G, and 53B is formed in a substantially U-shape that opens in the +Z direction when viewed from the +X direction. The red heat transport member 53R corresponds to the first heat transport member. The red heat transport member 53R thermally connects the red light source 41R and the red heat dissipation member 52R, and transports the heat generated in the red light source 41R to the red heat dissipation member 52R. The green heat transport member 53G corresponds to the second heat transport member. The green heat transport member 53G thermally connects the green light source 41G and the green heat dissipation member 52G, and transports the heat generated in the green light source 41G to the green heat dissipation member 52G. The blue heat transport member 53B corresponds to the third heat transport member. The blue heat transport member 53B thermally connects the blue light source 41B and the blue heat dissipation member 52B, and transports the heat generated in the blue light source 41B to the blue heat dissipation member 52B. Examples of such heat transport members 53R, 53G, and 53B include heat pipes.

[0028] [Configuration of the rectifier plate] Figure 7 is a perspective view showing the cooling fan 51, heat dissipation member 52, and rectifier plate 54 as seen from the +Y direction. Figure 8 is a diagram showing the positional relationship between the optical modulation elements 45R, 45G, 45B and the flow sections 541R, 541G, 541B, and is a plan view showing the optical modulation elements 45R, 45G, 45B and the flow sections 541R, 541G, 541B as seen from the +Y direction. As shown in Figure 3, the rectifier plate 54 is a plate-shaped member positioned between the projection light generation device 4 and the cooling fan 51 in the +Y direction, and rectifies the airflow generated by the cooling fan 51. More specifically, the rectifier plate 54 is positioned between the image forming apparatus 44 and the cooling fan 51. As shown in Figures 7 and 8, the rectifier plate 54 has three flow sections 541 through which the cooling gas passes. The three flow sections 541 include a flow section 541R for red, a flow section 541G for green, and a flow section 541B for blue. As shown in Figure 8, the red light distribution section 541R is positioned in the -Y direction relative to the red light modulation element 45R. The green light distribution section 541G is positioned in the -Y direction relative to the green light modulation element 45G. The blue light distribution section 541B is positioned in the -Y direction relative to the blue light modulation element 45B.

[0029] Each distribution section 541 has a protruding portion 542 and an opening 543, as shown in Figures 7 and 8. The protrusion 542 projects in a roughly truncated square pyramidal shape toward the corresponding optical modulation element among the optical modulation elements 45R, 45G, and 45B. The area of ​​the cross-section of the protrusion 542 perpendicular to the +Y direction decreases as it moves toward the +Y direction.

[0030] The opening 543 is formed in a substantially rectangular shape at the tip of the protruding portion 542. That is, the opening 543 penetrates the protruding portion 542 along the +Y direction. For the sake of explanation, the opening 543 of the red flow section 541R will be referred to as the red opening 543R, the opening 543 of the green flow section 541G will be referred to as the green opening 543G, and the opening 543 of the blue flow section 541B will be referred to as the blue opening 543B. The red light opening 543R corresponds to the first opening. The cooling gas discharged from the cooling fan 51 and passing through the red light opening 543R in the +Y direction flows to the red light source 41R and the red light modulation element 45R. The green opening 543G corresponds to the second opening. The cooling gas discharged from the cooling fan 51 and passing through the green opening 543G in the +Y direction flows to the green light source 41G and the green light modulation element 45G. The blue light opening 543B corresponds to the third opening. The cooling gas discharged from the cooling fan 51 and passing through the blue light opening 543B in the +Y direction flows along the blue light source 41B and the blue light modulation element 45B.

[0031] When the cooling fan 51 sends cooling gas in the -Y direction, the portion in the +Y direction relative to the cooling fan 51 becomes the intake side of the cooling fan 51. Therefore, when the cooling fan 51 is driven, a portion of the cooling gas flows along the red light source 41R and the red light modulator 45R, passes through the red opening 543R, and is drawn into the cooling fan 51. Similarly, another portion of the cooling gas flows along the green light source 41G and the green light modulator 45G, passes through the green opening 543G, and is drawn into the cooling fan 51. Furthermore, another portion of the cooling gas flows along the blue light source 41B and the blue light modulator 45B, passes through the blue opening 543B, and is drawn into the cooling fan 51.

[0032] The opening area of ​​the red opening 543R is larger than the opening area of ​​the green opening 543G and also larger than the opening area of ​​the blue opening 543B. In other words, the inner diameter of the red opening 543R is larger than the inner diameter of the green opening 543G and also larger than the inner diameter of the blue opening 543B. Therefore, the flow rate of the cooling gas passing through the red opening 543R is greater than the flow rate of the cooling gas passing through the green opening 543G and also greater than the flow rate of the cooling gas passing through the blue opening 543B. That is, the flow rate of the cooling gas flowing through the red light source 41R is greater than the flow rate of the cooling gas flowing through the green light source 41G and also greater than the flow rate of the cooling gas flowing through the blue light source 41B. Similarly, the flow rate of the cooling gas flowing through the red light modulation element 45R is greater than the flow rate of the cooling gas flowing through the green light modulation element 45G and also greater than the flow rate of the cooling gas flowing through the blue light modulation element 45B. This is because, among the red light source 41R, green light source 41G, and blue light source 41B, the red light source 41R exhibits the largest decrease in emitted light output when its temperature falls outside the appropriate temperature range. Therefore, in this embodiment, the cooling efficiency of the red light source 41R is increased compared to the cooling efficiency of the green light source 41G and the blue light source 41B, thereby maintaining the temperature of the red light source 41R within the appropriate temperature range.

[0033] [Cooling gas flow within the internal enclosure] Figure 9 shows a cross-section of the internal enclosure 3 along the YZ plane. In other words, Figure 9 shows the flow path of the cooling gas within the internal enclosure 3. As shown by arrow AR1 in Figure 9, when the cooling fan 51 is driven, it draws in the cooling gas in the space in the -Y direction relative to the cooling fan 51. Therefore, the cooling fan 51 draws in the cooling gas that has been individually circulating to each heat dissipation member 52R, 52G, and 52B. In other words, when the cooling fan 51 is driven, the cooling gas circulates to each heat dissipation member 52R, 52G, and 52B in the +Y direction. As a result, a portion of the heat generated by the light sources 41R, 41G, and 41B is dissipated from the corresponding heat dissipation member 52R, 52G, and 52B into the cooling gas.

[0034] The cooling fan 51, which draws in the cooling gas flowing along the heat dissipation members 52R, 52G, and 52B, sends the drawn-in cooling gas toward the rectifier plate 54 in the +Y direction. As a result, as shown by the arrow AR2 in Figure 9, the cooling gas flows through the openings 543R, 543G, and 543B of each flow section 541R, 541G, and 541B to the corresponding optical modulation elements 45R, 45G, and 45B. The cooling gas flows along the optical modulation elements 45R, 45G, and 45B in the +Y direction, cooling them. In addition, a portion of the cooling gas that has passed through the openings 543R, 543G, and 543B flows along each light source 41R, 41G, and 41B.

[0035] The cooling gas flowing in the +Y direction along the light sources 41R, 41G, 41B and the light modulation elements 45R, 45G, 45B flows along the inner surface of the top surface 33, as shown by arrow AR3 in Figure 9. Of the cooling gas that flows along the inner surface of the top surface 33, some flows along the inner surface of the back surface 32 in the -Y direction, as shown by arrows AR4 and AR5 in Figure 9. Although not shown in the figure, the remaining cooling gas that flows along the inner surface of the top surface 33 flows along the inner surfaces of the front surface 31, the right side surface 35, and the left side surface 36 in the -Y direction. The cooling gas that flows along the inner surface of the internal enclosure 3 in the -Y direction flows along the inner surface of the bottom surface 34, as shown by arrow AR6 in Figure 9. Then, as drawn in by the cooling fan 51, the cooling gas flows along each heat dissipation member 52R, 52G, and 52B in the +Y direction, as shown by the arrow AR1 in Figure 6.

[0036] In this manner, the cooling gas circulates within the internal housing 3 by the cooling fan 51, cooling each heat dissipation component 52R, 52G, 52B, each light source 41R, 41G, 41B, and the light modulation elements 45R, 45G, 45B. Furthermore, as the cooling gas that has cooled these components flows along the inner surface of the internal housing 3, the internal housing 3 absorbs heat from the cooling gas. The internal housing 3 then dissipates the heat absorbed by the cooling gas to the outside of the internal housing 3. This cools the cooling gas. In other words, the heat inside the internal housing 3 is dissipated to the outside of the internal housing 3. In this case, for example, the outer surface of the inner casing 3 dissipates the heat from inside the inner casing 3 into a gas that is introduced into the outer casing 2 and discharged to the outside of the outer casing 2.

[0037] [Control device configuration] Figure 10 is a block diagram showing the configuration of the control device 6A. The control device 6A controls the operation of the projector 1A. For example, the control device 6A processes the image information input to the projector 1A, outputs an image signal corresponding to the processed image information to the optical modulator 45, and causes the projection light generator 4 to form image light. The control device 6A also controls the lighting of the light source device 41. Furthermore, if the control device 6A detects a helium gas leak from the internal housing 3, it notifies the user of the projector 1A of the helium gas leak. For this purpose, the control device 6A has a monitor circuit 61, a memory 62, and a processor 63, as shown in Figure 10.

[0038] The monitoring circuit 61 detects the rotational speed of the cooling fan 51 per unit time. The monitoring circuit 61 outputs the detected rotational speed to the processor 63. Memory 62 stores the programs and data necessary for the operation of projector 1A. For example, memory 62 stores correspondence information that shows the relationship between the voltage applied to the cooling fan 51 and its rotational speed in a helium environment.

[0039] The processor 63 determines whether or not helium gas is leaking from the internal enclosure 3 based on the rotational speed of the cooling fan 51 detected by the monitoring circuit 61. Specifically, the processor 63 refers to the corresponding information stored in the memory 62 and obtains the rotational speed corresponding to the voltage currently applied to the cooling fan 51. Then, if the rotational speed obtained from the monitoring circuit 61 is less than the rotational speed obtained from the corresponding information, the processor 63 notifies that helium gas is leaking. Here, since the specific gravity of helium gas is lighter than that of air, the rotational speed of the cooling fan 51 in a helium environment will be higher than that in an air environment, provided the same voltage is applied to the cooling fan 51 as in an air environment. On the other hand, as the internal environment of the internal housing 3 approaches that of air, the rotational speed of the cooling fan 51 decreases. Therefore, the processor 63 can determine the state of helium gas filling inside the internal enclosure 3 by determining the rotational speed obtained from the monitor circuit 61. Furthermore, the processor 63 may notify the user of helium gas leakage by, for example, illuminating an indicator on the outer casing 2 and displaying a warning screen on the projection light generator 4.

[0040] [Effects of the First Embodiment] The projector 1A according to this embodiment, as described above, provides the following effects. Projector 1A comprises an internal housing 3, a projection light generation device 4, a cooling fan 51, and a heat dissipation member 52. The projection light generator 4 generates projection light. The cooling fan 51 generates an airflow to which the heat generated by the projection light generator 4 is transferred. The heat dissipation member 52 dissipates the transferred heat into the airflow generated by the cooling fan 51. The internal housing 3 corresponds to the housing and houses the projection light generator 4, the cooling fan 51, and the heat dissipation member 52. The projection light generation device 4 includes a light source device 41, a light modulation device 45, and a photosynthesis device 46. The light source device 41 includes a red light source 41R that emits red light as the first light, a green light source 41G that emits green light as the second light, and a blue light source 41B that emits blue light as the third light. The red light source 41R corresponds to the first light source, the green light source 41G corresponds to the second light source, and the blue light source 41B corresponds to the third light source. The light modulation device 45 includes a red light modulation element 45R that modulates red light, a green light modulation element 45G that modulates green light, and a blue light modulation element 45B that modulates blue light. The red light modulation element 45R corresponds to the first light modulation element, the green light modulation element 45G corresponds to the second light modulation element, and the blue light modulation element 45B corresponds to the third light modulation element. The photosynthetic apparatus 46 synthesizes red light, green light, and blue light modulated by the light modulator 45.

[0041] The cooling fan 51 is positioned to overlap with the light modulator 45 and the photosynthesis device 46 when viewed from the ±Y direction, which is perpendicular to the XZ plane containing the optical axes of red, green, and blue light. The +Y direction or -Y direction corresponds to the first direction. The heat dissipation member 52 is positioned to overlap with the cooling fan 51 when viewed from the -Y direction. That is, the cooling fan 51 is positioned to overlap with the projection light generator 4 and the heat dissipation member 52 when viewed from the +Y direction, which is perpendicular to the XZ plane containing the optical axes of red, green, and blue light. The projection light generation device 4 and the heat dissipation member 52 are separated by a cooling fan 51 in the +Y direction. The cooling fan 51 generates an airflow that circulates in the +Y direction.

[0042] With this configuration, the operation of the cooling fan 51 generates an airflow that flows from the heat dissipation member 52 toward the projection light generation device 4. This airflow can cool the light source device 41 and the light modulation device 45 that make up the projection light generation device 4, as well as the heat dissipation member 52. Here, within the internal housing 3, the light modulator 45, the photosynthesis device 46, the cooling fan 51, and the heat dissipation member 52 are arranged to overlap in the +Y direction. Therefore, the area of ​​the bottom surface 34 perpendicular to the +Y direction in the internal housing 3 can be reduced. Consequently, when the +Y direction is aligned with the vertical direction, the area of ​​the bottom surface 24 of the projector 1A can be reduced, and the projector 1A can be made smaller.

[0043] Projector 1A is positioned between the projection light generation device 4 and the cooling fan 51 in the +Y direction and includes a rectifier plate 54 that rectifies the airflow generated by the cooling fan 51. The rectifier plate 54 has a red opening 543R, a green opening 543G, and a blue opening 543B. The red opening 543R corresponds to the first opening and is provided in accordance with the red light modulation element 45R, through which a portion of the airflow passes. The green opening 543G corresponds to the second opening and is provided in accordance with the green light modulation element 45G, through which a portion of the airflow passes. The blue opening 543B corresponds to the third opening and is provided in accordance with the blue light modulation element 45B, through which a portion of the airflow passes. With this configuration, when the cooling fan 51 directs airflow toward the projection light generator 4, the airflow sent from the cooling fan 51 flows through the openings 543R, 543G, and 543B and then to the optical modulation elements 45R, 45G, and 45B. Because these openings 543R, 543G, and 543B are provided according to the optical modulation elements 45R, 45G, and 45B, the airflow circulated by the cooling fan 51 can be effectively directed to the optical modulation elements 45R, 45G, and 45B, thereby increasing the cooling efficiency of the optical modulator 45.

[0044] In projector 1A, the red light source 41R is an LED that emits red light. The opening area of ​​the red opening 543R is larger than the opening area of ​​the green opening 543G and the blue opening 543B. The airflow through the red opening 543R flows along the red light source 41R and the red light modulation element 45R. Here, red LEDs that emit red light are more sensitive to temperature than blue LEDs that emit blue light and green LEDs that emit green light. Outside the appropriate temperature range, the amount of light emitted by a red LED decreases significantly compared to the amount of light emitted by a red LED within the appropriate temperature range. On the other hand, red LEDs generate heat when emitting red light. In contrast, the aperture area of ​​the red aperture 543R, which is provided in accordance with the red light source 41R (a red LED), is larger than the aperture area of ​​the green aperture 543G and the blue aperture 543B. This allows the airflow rate to flow through the red light source 41R and the red light modulation element 45R to be increased compared to the airflow rate to flow through the other light sources and other light modulation elements. Therefore, the cooling efficiency of the red light source 41R and the red light modulation element 45R can be improved.

[0045] In projector 1A, the heat dissipation member 52 includes a red heat dissipation member 52R that is thermally connected to the red light source 41R, and a green heat dissipation member 52G that is provided independently of the red heat dissipation member 52R and thermally connected to the green light source 41G. The red heat dissipation member 52R corresponds to the first heat dissipation member, and the green heat dissipation member 52G corresponds to the second heat dissipation member. With this configuration, airflow can be circulated through the red heat dissipation member 52R and the green heat dissipation member 52G, allowing them to be cooled independently of each other. In other words, the red light source 41R and the green light source 41G can be cooled thermally independently of each other. Therefore, it is possible to suppress the transfer of heat generated in one of the light sources, the red light source 41R or the green light source 41G, to the other light source. The same applies when the blue light source 41B corresponds to the second light source.

[0046] In projector 1A, the heat dissipation member 52 is provided independently of the red heat dissipation member 52R and the green heat dissipation member 52G, and includes a blue heat dissipation member 52B that is thermally connected to the blue light source 41B. With this configuration, airflow circulates through each heat dissipation component 52R, 52G, and 52B, allowing each heat dissipation component 52R, 52G, and 52B to be cooled independently of each other. As a result, the red light source 41R, the green light source 41G, and the blue light source 41B can be cooled thermally independently of each other. Therefore, the transfer of heat generated in any of the light sources—the red light source 41R, the green light source 41G, and the blue light source 41B—to the other light sources can be suppressed, thus effectively cooling the red light source 41R, the green light source 41G, and the blue light source 41B.

[0047] In projector 1A, the projection light generation device 4 is housed in a sealed state within the internal casing 3. With this configuration, dust cannot enter the internal housing 3 from the outside. Therefore, dust cannot adhere to the projection light generator 4, and the quality of the image light generated by the projection light generator 4 cannot be reduced.

[0048] Projector 1A, and projection light generation device 4, have a lens barrel 472 that houses a lens 471 and a projection lens 47 that projects the light synthesized by the photosynthesis device 46. The internal housing 3 has an opening 311 through which projected light passes, and a sealing member 312 that seals the opening 311 with a part of the lens barrel 472 positioned inside the opening 311. With this configuration, a portion of the projection lens 47 is located inside the internal housing 3. In other words, the other portion of the projection lens 47 is located outside the internal housing 3. Therefore, the internal housing 3 can be made smaller compared to the case where the entire projection lens 47 is located inside the internal housing 3. Consequently, the area of ​​the bottom surface 24 of the projector 1A can be reduced, and the projector 1A can be made smaller.

[0049] Projector 1A includes an outer casing 2 that houses the internal housing 3 and projection lens 47, and constitutes the exterior of Projector 1A. With this configuration, the internal housing 3 is placed inside the outer housing 2. This effectively prevents dust from entering the internal housing 3. Furthermore, since the projector 1A is manufactured by placing the internal housing 3, which already contains the projection light generation device 4, cooling fan 51, and heat dissipation member 52, inside the outer housing 2, the assembly process of the projector 1A can be simplified.

[0050] In projector 1A, a cooling gas having a higher thermal conductivity than air is sealed inside the internal casing 3. With this configuration, the cooling fan 51 is driven, causing the gas to circulate to the light projection generator 4 and the heat dissipation member 52, thereby increasing the cooling efficiency of the light projection generator 4 and the heat dissipation member 52.

[0051] Projector 1A is equipped with a monitoring circuit 61 that monitors the rotation speed of the cooling fan 51. The cooling gas sealed inside the internal housing 3 is helium gas. Here, the relationship between the voltage applied to the cooling fan 51 and its rotational speed changes depending on the gas passing through the cooling fan 51. When helium gas, which has a higher thermal conductivity than air, is sealed inside the internal housing 3, the rotational speed of the cooling fan 51 will differ between a helium environment and an air environment, even when the same voltage is applied. Specifically, the rotational speed of the cooling fan 51 is higher in a helium environment than in an air environment. Therefore, by monitoring the rotation speed of the cooling fan 51, it is possible to determine whether or not helium gas is leaking from the internal casing 3. Therefore, since helium gas leakage from the internal housing 3 can be detected without the need for special sensors, it is possible to prevent the projector 1A from becoming overly complex or its manufacturing costs from increasing.

[0052] In projector 1A, the internal housing 3 has an injection hole 371 into which cooling gas can be injected. The injection hole 371 is located on the intake side of the cooling fan 51. With this configuration, when the cooling fan 51 is driven, the intake side of the cooling fan 51 becomes negative pressure. Therefore, it is possible to suppress the leakage of the cooling gas sealed inside the internal housing 3 to the outside of the internal housing 3 through the injection hole 371.

[0053] In projector 1A, the internal housing 3 has a cover member 374 that covers the injection hole 371. With this configuration, the injection hole 371 can be protected by the cover member 374. This prevents damage to the injection hole 371 and prevents cooling gas from leaking out of the injection hole 371 to the outside of the internal housing 3.

[0054] In projector 1A, the photosynthesis device 46 has a red incident surface 46R, a green incident surface 46G, a blue incident surface 46B, and an exit surface 46S. The red light source 46R is the first incident surface facing the red light modulator 45R. The green light source 46G is the second incident surface that intersects with the red light source 46R and faces the green light modulator 45G. The blue light source 46B is the third incident surface located on the opposite side of the red light source 46R and faces the blue light modulator 45B. The output surface 46S is located on the opposite side of the green light source 46G and emits projected light. The red light source 41R faces the red light modulator 45R, the green light source 41G faces the green light modulator 45G, and the blue light source 41B faces the blue light modulator 45B. With this configuration, the light sources 41R, 41G, 41B, the light modulation elements 45R, 45G, 45B, and the photosynthesis device 46 can be arranged compactly. Therefore, the projector 1A can be miniaturized. In addition, this makes it easier to cool the light sources 41R, 41G, 41B and the light modulation elements 45R, 45G, 45B with the airflow generated by a single cooling fan 51.

[0055] [First modified example of the first embodiment] In the above-described projector 1A, the cooling fan 51 is configured to draw in cooling gas in the space in the -Y direction relative to the cooling fan 51 and send out the drawn-in cooling gas in the +Y direction. However, the projector is not limited to this configuration, and the cooling fan 51 may also draw in cooling gas in the space in the +Y direction relative to the cooling fan 51 and send out the drawn-in cooling gas in the -Y direction. That is, the cooling fan 51 may draw in the cooling gas that has cooled each of the optical modulation elements 45R, 45G, and 45B via the rectifier plate 54 and send out the drawn-in cooling gas to each of the heat dissipation members 52R, 52G, and 52B. In this case, the intake side of the cooling fan 51 is a space in the -Y direction relative to the cooling fan 51. For this reason, it is preferable that the injection section 37 be provided in the part of the internal housing 3 in the -Y direction relative to the cooling fan 51. Also, the flow section 541 of the rectifier plate 54 does not need to have a protruding section 542.

[0056] With this configuration, the cooling fan 51 is driven to generate an airflow that flows from the light projection device 4 towards the heat dissipation member 52. This airflow can cool the light source device 41 and the light modulation device 45 that make up the light projection device 4, as well as the heat dissipation member 52. Furthermore, when the cooling fan 51 directs airflow toward the heat dissipation member 52, the airflow flows along each of the optical modulation elements 45R, 45G, and 45B before being drawn in by the cooling fan 51 through the openings 543R, 543G, and 543B of the rectifier plate 54. Therefore, by providing each of the openings 543R, 543G, and 543B according to each of the optical modulation elements 45R, 45G, and 45B, the airflow circulated by the cooling fan 51 can be effectively directed toward each of the optical modulation elements 45R, 45G, and 45B, thereby increasing the cooling efficiency of the optical modulation device 45.

[0057] [Second modified example of the first embodiment] In projector 1A, the green light source 41G, as a second light source, is thermally connected to the green heat dissipation member 52G, as a second heat dissipation member, and the blue light source 41B, as a third light source, is thermally connected to the blue heat dissipation member 52B, as a third heat dissipation member. However, this is not limited to this configuration; the heat dissipation member 52 may not have a blue heat dissipation member 52B, and the blue light source 41B may be thermally connected to the green heat dissipation member 52G. This configuration allows for a reduction in the number of components in the heat dissipation member 52. Consequently, the configuration of the projector 1A can be simplified, and the product cost of the projector 1A can be reduced.

[0058] [Second Embodiment] Next, a second embodiment of this disclosure will be described. The projector according to this embodiment has the same configuration as the projector according to the first embodiment, but differs in that it does not have an internal housing 3 and the outer housing 2 is a sealed housing. In the following description, parts that are the same or substantially the same as those already described are denoted by the same reference numerals and their description is omitted.

[0059] [Projector Configuration Overview] Figure 11 is a perspective view showing the projector 1B according to this embodiment. As shown in Figure 11, the projector 1B according to this embodiment has the same configuration and functions as the projector 1B according to the first embodiment, except that it includes an outer housing 2B instead of the outer housing 2 and the inner housing 3. That is, the projector 1B includes an outer housing 2B and a projection light generation device 4 and a cooling device 5 housed inside the outer housing 2B.

[0060] The outer casing 2B is a sealed casing that prevents dust from easily entering the interior, and corresponds to the casing according to this embodiment. The outer casing 2B is made of a material with high thermal conductivity, such as metal, and dissipates heat from inside the outer casing 2 to the outside. Although not shown in Figure 11, the outer casing 2B has an injection part similar to the injection part 37 provided in the inner casing 3 described above. The cooling gas described above is filled inside the outer casing 2B. When the cooling fan 51 of the cooling device 5 is driven, the cooling gas inside the outer casing 2B circulates within the outer casing 2B to cool each light source 41R, 41G, 41B, each optical modulation element 45R, 45G, 45B, and heat dissipation members 52R, 52G, 52B. The cooling fan 51 may send the cooling gas in the +Y direction or in the -Y direction.

[0061] [Effects of the second embodiment] The projector 1B according to this embodiment, as described above, provides the same effects as the projector 1A according to the first embodiment, as well as the following effects. In projector 1B, the exterior housing 2 that constitutes the exterior corresponds to the housing of this disclosure. This configuration reduces the number of parts in projector 1B, thereby lowering the manufacturing cost of projector 1B. In addition, the area of ​​the bottom surface 24 of projector 1B can be made smaller, allowing for a more compact projector 1B.

[0062] [Third Embodiment] Next, a third embodiment of this disclosure will be described. The projector according to this embodiment has the same configuration as the projectors 1A and 1B according to the first and second embodiments, but differs in that the direction of cooling gas discharge by the cooling fan 51 is switched according to the state of the projector. In the following description, parts that are the same or substantially the same as those already described are denoted by the same reference numerals and their description is omitted.

[0063] [Projector Configuration Overview] Figure 12 is a block diagram showing the configuration of the control device 6B included in the projector according to this embodiment. The projector according to this embodiment has the same configuration and functions as the projector 1A according to the first embodiment, except that it further includes a control device 6B shown in Figure 8 instead of the control device 6A. The projector according to this embodiment may also have the same configuration as the projector 1B according to the second embodiment. The control device 6B controls the operation of the projector in the same manner as the control device 6A in the first embodiment. Furthermore, the control device 6B controls the cooling fan 51 according to the state of the projector. For this purpose, the control device 6B includes a monitor circuit 61, a memory 62, a processor 63, and a state acquisition unit 64.

[0064] The status acquisition unit 64 acquires the status of the projector 1B. The status acquisition unit 64 may include a temperature sensor for detecting the temperature of the light source device 41. In this case, for example, the status acquisition unit 64 may be a temperature sensor for detecting the temperature of the red light source 41R. The status acquisition unit 64 may also acquire the cumulative operating time of the projection light generation device 4 or the cumulative lighting time of the light source device 41. Alternatively, the status acquisition unit 64 may be an illuminance sensor for detecting the illuminance of any of the red light, green light, blue light, and projection light.

[0065] In this embodiment, the processor 63 not only determines the rotation speed of the cooling fan 51 using the monitor circuit 61, but also switches the rotation direction of the cooling fan 51 based on the state of the projector 1B acquired by the state acquisition unit 64. In other words, the processor 63 switches the direction in which the cooling gas is discharged by the cooling fan 51 based on the state of the projector 1B.

[0066] For example, if the temperature of the light source device 41 detected by the state acquisition unit 64 is less than the reference temperature stored in the memory 62, the cooling fan 51 is switched to prioritize cooling the light modulator 45 by switching the rotation direction of the cooling fan 51 so that, for example, the position of the light modulator 45 becomes the upstream side of the airflow and the position of the heat dissipation member 52 becomes the downstream side of the airflow. In other words, in this case, the direction in which the cooling gas is discharged by the cooling fan 51 is the -Y direction, and the cooling gas that has been cooled by flowing along the inner surface of the internal housing 3 flows to each light modulator element 45R, 45G, 45B before the heat dissipation member 52. On the other hand, if the temperature of the light source device 41 is above the reference temperature, the rotation direction of the cooling fan 51 is switched so that, for example, the position of the heat dissipation member 52 is on the upstream side of the airflow and the position of the light modulation device 45 is on the downstream side of the airflow, thereby prioritizing the cooling of the heat dissipation member 52, and consequently the cooling of the light source device 41. In other words, in this case, the direction in which the cooling gas is discharged by the cooling fan 51 is in the +Y direction, and the cooling gas that has been cooled by flowing along the inner surface of the internal housing 3 flows to each heat dissipation member 52R, 52G, 52B before the light modulation elements 45R, 45G, 45B.

[0067] Furthermore, if the cumulative operating time of the projection light generator 4 or the cumulative lighting time of the light source device 41 is longer than the standard time, or if the illuminance of at least one of the red light, green light, blue light, and projection light is below the standard illuminance, it is presumed that the light source device 41 is deteriorating. For this reason, if the cumulative operating time of the projection light generator 4 or the cumulative lighting time of the light source device 41 is longer than the standard time, or if the illuminance of at least one of the red light, green light, blue light, and projection light is below the standard illuminance, cooling of the heat dissipation member 52 is prioritized. If the cumulative operating time of the projection light generator 4 or the cumulative lighting time of the light source device 41 is less than the standard time, or if the illuminance of at least one of the red light, green light, blue light, and projection light is above the standard illuminance, cooling of the light modulation device 45 is prioritized. As described above, when prioritizing the cooling of the heat dissipation member 52, the processor 63 sets the direction of cooling gas discharge by the cooling fan 51 to the +Y direction, and when prioritizing the cooling of the optical modulator 45, the direction of cooling gas discharge by the cooling fan 51 to the +Y direction.

[0068] [Effects of the third embodiment] The projector according to this embodiment described above provides the same effects as the projector 1A according to the first embodiment, as well as the following effects. The projector according to this embodiment includes a control device 6B that controls the drive of the cooling fan 51. The control device 6B switches the rotation direction of the cooling fan 51 based on at least one of the temperature of the light source device 41, the cumulative operating time of the projection light generation device 4, and the illuminance of any of the red light, green light, blue light, and projection light.

[0069] With this configuration, the heat dissipation member 52, which receives heat from the light sources 41R, 41G, and 41B, and the light modulation device 45, which are the objects to be cooled with higher priority, can be placed on the upstream side of the airflow. Furthermore, if the temperature of the light source device 41 is below the reference temperature, the rotation direction of the cooling fan 51 is switched so that, for example, the position of the light modulator 45 is upstream of the airflow and the position of the heat dissipation member 52 is downstream of the airflow, thereby prioritizing the cooling of the light modulator 45. Conversely, if the temperature of the light source device 41 is above the reference temperature, the rotation direction of the cooling fan 51 is switched so that, for example, the position of the heat dissipation member 52 is upstream of the airflow and the position of the light modulator 45 is downstream of the airflow, thereby prioritizing the cooling of the heat dissipation member 52, and consequently the cooling of the light source device 41. On the other hand, if the cumulative operating time of the projection light generator 4 is longer than the standard time, or if the illuminance of at least one of the red light, green light, blue light, and projection light is below the standard illuminance, it is presumed that the light source device 41 is deteriorating. For this reason, if the cumulative operating time of the projection light generator 4 is longer than the standard time, or if the illuminance of at least one of the red light, green light, blue light, and projection light is below the standard illuminance, cooling of the heat dissipation member 52 is prioritized. If the cumulative operating time of the projection light generator 4 is less than the standard time, or if the illuminance of at least one of the red light, green light, blue light, and projection light is above the standard illuminance, cooling of the light modulation device 45 is prioritized. By switching the rotation direction of the cooling fan 51 in this way, the light source device 41 and the optical modulation device 45 can be effectively cooled according to the operating state of the projector.

[0070] [Variations of the Embodiment] This disclosure is not limited to the embodiments described above, and any modifications and improvements that can achieve the purposes of this disclosure are included. In each of the embodiments described above, the image forming apparatus 44 is positioned inside the cooling fan 51 when viewed from the +Y direction. However, the configuration is not limited to this, and it is sufficient that at least a part of the cooling fan 51 and at least a part of the projection light generation device 4 overlap each other when viewed from the +Y direction. In this case, at least a part of the cooling fan 51 and at least a part of the image forming apparatus 44 may overlap each other when viewed from the +Y direction. Furthermore, it is preferable that at least a portion of the heat dissipation member 52 is positioned to overlap with at least a portion of the cooling fan 51 when viewed from the +Y direction.

[0071] In each of the embodiments described above, a rectifier plate 54 is positioned between the light projection device 4 and the cooling fan 51. However, the rectifier plate 54 is not required. Furthermore, the rectifier plate 54 does not need to have a protrusion 542. Furthermore, in the rectifier plate 54, the opening area of ​​the red opening 543R is larger than the opening area of ​​the green opening 543G and also larger than the opening area of ​​the blue opening 543B. However, this is not limited to this, and the opening areas of each opening 543R, 543G, and 543B can be changed as appropriate. For example, the opening areas of each opening 543R, 543G, and 543B may be the same, and the opening area of ​​the green opening 543G may be larger than the opening areas of the other openings 543R and 543B.

[0072] In each of the above embodiments, the heat dissipation member 52 is provided with a red heat dissipation member 52R, a green heat dissipation member 52G, and a blue heat dissipation member 52B. In the second modification of the first embodiment, the heat dissipation member 52 does not include the blue heat dissipation member 52B. However, the heat dissipation member 52 is not limited to this, and the heat dissipation member 52 may be a single heat sink, to which the red light source 41R, the green light source 41G, and the blue light source 41B are thermally connected. Furthermore, the red light source 41R and the red heat dissipation member 52R are thermally connected via a heat pipe, which is a red heat transport member 53R. However, the red light source 41R and the red heat dissipation member 52R may be thermally connected by other means, or they may be directly connected. The same applies to the connection of other light sources and other heat dissipation members.

[0073] In the first and third embodiments described above, the internal housing 3, which houses the projection light generator 4, the cooling fan 51, and the heat dissipation member 52, is a sealed housing. In the second embodiment described above, the outer housing 2B, which houses the projection light generator 4, the cooling fan 51, and the heat dissipation member 52, is a sealed housing. However, the internal housing 3 and the outer housings 2 and 2B do not have to be sealed housings. In this case, the internal housing 3 may be provided with an inlet for introducing cooling gas into the interior and an outlet for discharging cooling gas to the outside of the internal housing 3. Similarly, the outer housings 2 and 2B may be provided with an inlet for introducing cooling gas into the interior and an outlet for discharging cooling gas to the outside of the outer housings 2 and 2B.

[0074] In each of the above embodiments, the projection light generating device 4 is provided with a projection lens 47. However, it is not limited to this, and the projection lens 47 may be omitted. In the first and third embodiments described above, a portion of the projection lens 47 is located outside the internal housing 3. In the second embodiment described above, a portion of the projection lens 47 is located outside the outer housing 2B. However, the invention is not limited to these configurations; the entire projection lens 47 may be located inside the internal housing 3, or the entire projection lens 47 may be located inside the outer housings 2 and 2B. In this case, the internal housing 3 and the outer housings 2 and 2B have openings through which projected light passes, and these openings may be covered with light-transmitting sealing members.

[0075] In the first and third embodiments described above, it was assumed that a cooling gas having a higher thermal conductivity than air was sealed inside the internal housing 3. However, the internal housing 3 is not limited to this, and may contain air, or other gases other than helium gas. Furthermore, the internal housing 3 may contain an inert liquid such as Fluorinert®.

[0076] In the embodiments described above, the control devices 6A and 6B have a monitoring circuit 61 that monitors the rotation speed of the cooling fan 51, and the processor 63 determines whether helium gas is leaking based on the detection results of the monitoring circuit 61. However, the invention is not limited to this, and the monitoring circuit 61 may be omitted. In this case, the control devices 6A and 6B may detect the helium gas leak by other means. Furthermore, the control devices 6A and 6B do not need to determine whether helium gas is leaking.

[0077] In the first and second embodiments described above, the injection section 37 is provided on the intake side of the cooling fan 51 in the internal housing 3 or the outer housing 2B. However, the position of the injection section 37 in the internal housing 3 and the outer housing 2B can be changed as appropriate. Furthermore, the injection section 37 is provided with a cover member 374 that covers the injection hole 371. However, this is not limited to this configuration, and the cover member 374 may be omitted. Also, the structure of the cover member 374 is not limited to tape; it may be a plug inserted into the injection hole 371 or other configurations.

[0078] In each of the embodiments described above, the layout of the optical components in the projection light generation device 4 is as shown in Figure 6. However, the projection light generation device 4 is not limited to this, and may also include an optical path changing member that changes the optical path of the colored light.

[0079] In the second embodiment described above, the control device 6B switches the rotation direction of the cooling fan 51 based on the temperature of the light source device 41, the cumulative operating time of the projection light generation device 4 or the cumulative lighting time of the light source device 41, and the illuminance of any of the red light, green light, blue light, and projection light. However, the control device 6B is not limited to this and may switch the rotation direction of the cooling fan 51 and the flow direction of the cooling gas based on two or more of the temperature of the light source device 41, the cumulative operating time, the cumulative lighting time, and the illuminance.

[0080] In each of the above embodiments, the heat dissipation member 52 is assumed to dissipate heat transferred from the light source device 41. However, it is not limited to this, and heat may be transferred to the heat dissipation member 52 from other objects to be cooled. In other words, the heat dissipation member 52 may dissipate heat transferred from components other than the light source device 41.

[0081] In the embodiments described above, red light was designated as the first light, green light as the second light, and blue light as the third light. However, the embodiments are not limited to these configurations; any one of the red, green, and blue lights can be designated as the first light, another as the second light, and the remaining one as the third light. Furthermore, the first, second, and third lights are not limited to red, green, and blue light, but may be other colors of light or other polarized lights.

[0082] [Summary of this disclosure] A summary of this disclosure is provided below. [Note 1] A projection light generating device that generates projected light, A cooling fan generates an airflow through which the heat generated by the aforementioned projection light generating device is transferred, A heat dissipation member that releases the transferred heat into the airflow, The system comprises the aforementioned light projection device, the cooling fan, and the heat dissipation member, The aforementioned projection light generating device is A light source device having a first light source that emits first light, a second light source that emits second light, and a third light source that emits third light, An optical modulation device having a first optical modulation element for modulating the first light, a second optical modulation element for modulating the second light, and a third optical modulation element for modulating the third light, A photosynthetic apparatus that synthesizes the first light, the second light, and the third light modulated by the light modulation device, The cooling fan is positioned so as to overlap the projection light generating device and the heat dissipation member when viewed from a first direction perpendicular to the plane containing the optical axes of the first light, the second light, and the third light. The projection light generating device and the heat dissipation member are positioned with the cooling fan in the first direction, The cooling fan generates the airflow that flows in one of the first direction and the direction opposite to the first direction. A projector characterized by the following features.

[0083] With this configuration, the operation of the cooling fan generates an airflow that flows from one of the projection light generation device and the heat dissipation member towards the other. This airflow can cool the light source device and the light modulation device that make up the projection light generation device, as well as the heat dissipation member. In this configuration, the light modulator, photosynthesis device, cooling fan, and heat dissipation member are arranged to overlap in the first direction within the enclosure. This reduces the area of ​​the surfaces perpendicular to the first direction within the enclosure. Consequently, when the first direction is aligned with the vertical, the area of ​​the projector's base can be reduced, allowing for a more compact projector.

[0084] [Note 2] In the projector described in Appendix 1, The device is positioned between the projection light generating device and the cooling fan in the first direction and includes a rectifier plate for rectifying the airflow, The aforementioned rectifier plate is A first opening is provided according to the first optical modulation element, through which a portion of the airflow passes, A second opening is provided according to the second optical modulation element, through which a portion of the airflow passes, A third opening is provided according to the third optical modulation element, through which a portion of the airflow passes, A projector characterized by the following features. In this configuration, when the cooling fan directs airflow toward the light projection generator, the airflow sent from the cooling fan flows through each opening and then to each light modulation element. On the other hand, when the cooling fan directs airflow toward the heat dissipation member, the airflow flows along each light modulation element and then is drawn in by the cooling fan through each opening. Therefore, since each opening is provided according to each optical modulation element, the airflow circulated by the cooling fan can be effectively directed to each optical modulation element, thereby improving the cooling efficiency of the optical modulation device.

[0085] [Note 3] In the projector described in Appendix 2, The first light source is an LED that emits the first light, which is red light. The opening area of ​​the first opening is larger than the opening area of ​​the second opening and the opening area of ​​the third opening. The airflow flowing through the first opening flows along the first light source and the first light modulation element. A projector characterized by the following features. Here, red LEDs that emit red light are more sensitive to temperature than blue LEDs that emit blue light and green LEDs that emit green light. Outside the appropriate temperature range, the amount of light emitted by a red LED decreases significantly compared to the amount of light emitted by a red LED within the appropriate temperature range. On the other hand, red LEDs generate heat when emitting red light. In contrast, by making the opening area of ​​the first aperture, which is provided according to the first light source (a red LED), larger than the opening areas of the second and third apertures, the airflow rate to the first light source and the first optical modulation element can be increased. Therefore, the cooling efficiency of the first light source and the first optical modulation element can be improved.

[0086] [Note 4] In the projector described in any one of the appendices 1 to 3, The heat dissipation member is A first heat dissipation member thermally connected to the first light source, The system includes a second heat dissipation member provided independently of the first heat dissipation member and thermally connected to the second light source, A projector characterized by the following features. With this configuration, the first and second heat dissipation members can be cooled independently of each other by the airflow through them. In other words, the first and second light sources can be cooled thermally independently of each other. Therefore, the transfer of heat generated in one of the two light sources to the other can be suppressed.

[0087] [Note 5] In the projector described in Appendix 4, The third light source is thermally connected to the second heat dissipation member. A projector characterized by the following features. This configuration reduces the number of components in the heat dissipation system. Consequently, the projector's configuration can be simplified, lowering the product cost of the projector.

[0088] [Note 6] In the projector described in Appendix 4, The heat dissipation member includes a third heat dissipation member that is provided independently of the first heat dissipation member and the second heat dissipation member and is thermally connected to the third light source. A projector characterized by the following features. With this configuration, airflow circulates through each heat dissipation component, allowing each component to be cooled independently of the others. As a result, the first, second, and third light sources can be cooled thermally independently of each other. Therefore, heat generated in any of the first, second, and third light sources cannot be transferred to the other light sources, allowing each light source to be cooled effectively.

[0089] [Note 7] In the projector described in any one of the appendices 4 to 6, The system includes a control device that controls the operation of the cooling fan, The control device switches the rotation direction of the cooling fan based on at least one of the temperature of the light source device, the cumulative operating time of the projection light generation device, and the illuminance of any of the first light, second light, third light, and projection light. A projector characterized by the following features.

[0090] With this configuration, the heat dissipation component that receives heat from the light source and the light modulation device, which are the components to be cooled with higher priority, can be placed upstream of the airflow. Furthermore, if the temperature of the light source device is below the reference temperature, the rotation direction of the cooling fan is switched so that, for example, the position of the light modulator is upstream of the airflow and the position of the heat dissipation component is downstream of the airflow, thereby prioritizing the cooling of the light modulator. Conversely, if the temperature of the light source device is above the reference temperature, the rotation direction of the cooling fan is switched so that, for example, the position of the heat dissipation component is upstream of the airflow and the position of the light modulator is downstream of the airflow, thereby prioritizing the cooling of the heat dissipation component, and consequently the cooling of the light source device. On the other hand, if the cumulative operating time of the projection light generation device is longer than the standard time, or if the illuminance of at least one of the first light, second light, third light, and projection light is below the standard illuminance, it is presumed that the light source device is deteriorating. For this reason, if the cumulative operating time of the projection light generation device is longer than the standard time, or if the illuminance of at least one of the first light, second light, third light, and projection light is below the standard illuminance, cooling of the heat dissipation component is prioritized. If the cumulative operating time of the projection light generation device is less than the standard time, or if the illuminance of at least one of the first light, second light, third light, and projection light is above the standard illuminance, cooling of the light modulation device is prioritized. By switching the rotation direction of the cooling fan in this way, the light source device and the optical modulation device can be effectively cooled according to the operating status of the projector.

[0091] [Note 8] In the projector described in any one of the appendices 1 through 7, The projection light generating device is housed in a sealed state within the housing. A projector characterized by the following features. This configuration prevents dust from entering the enclosure from the outside. Consequently, dust accumulation on the projection light generator is prevented, and the quality of the image light generated by the projection light generator is prevented from degrading.

[0092] [Note 9] In the projector described in Appendix 8, The projection light generation device has a lens barrel that houses a lens, and includes a projection lens that projects the projection light synthesized by the photosynthesis device. The aforementioned enclosure is The opening through which the projected light passes, The device includes a sealing member that seals the opening while a part of the lens barrel is positioned inside the opening. A projector characterized by the following features. In this configuration, part of the projection lens is located inside the housing. In other words, the other part of the projection lens is located outside the housing. Therefore, the housing can be made smaller compared to when the entire projection lens is located inside the housing. Consequently, the area of ​​the projector's base can be reduced, allowing for a more compact projector.

[0093] [Note 10] In the projector described in Appendix 9, The system includes an outer casing that houses the aforementioned housing and the projection lens, and constitutes the outer casing. A projector characterized by the following features. With this configuration, the enclosure becomes an internal enclosure placed inside the outer enclosure. This effectively prevents dust from entering the enclosure. Furthermore, since the projector is manufactured by placing an enclosure with the projection light generation device, cooling fan, and heat dissipation components already installed inside inside the outer enclosure, the projector assembly process can be simplified.

[0094] [Note 11] In the projector described in any one of the appendices 1 through 9, The aforementioned enclosure is an outer enclosure that constitutes the exterior. A projector characterized by the following features. This configuration reduces the number of parts in the projector, thereby lowering the manufacturing cost. Additionally, it allows for a smaller base area, enabling a more compact projector.

[0095] [Note 12] In the projector described in any one of the appendices 1 through 11, The enclosure contains a gas having a higher thermal conductivity than that of air. A projector characterized by the following features. With this configuration, the cooling fan drives the gas to circulate to the light projection device and the heat dissipation member, thereby increasing the cooling efficiency of the light projection device and the heat dissipation member.

[0096] [Note 13] In the projector described in Appendix 12, The system includes a monitoring circuit that monitors the rotation speed of the cooling fan, The aforementioned gas is helium gas. A projector characterized by the following features. Here, the relationship between the voltage applied to the cooling fan and its rotational speed changes depending on the gas passing through the cooling fan. If helium gas, which has a higher thermal conductivity than air, is sealed inside the enclosure, the rotational speed of the cooling fan will differ between a helium environment and an air environment, even when the same voltage is applied. Specifically, the rotational speed of the cooling fan will be higher in a helium environment than in an air environment. Therefore, by monitoring the rotation speed of the cooling fan, it is possible to determine whether or not helium gas is leaking from the casing. Therefore, since helium gas leakage from the casing can be detected without the need for special sensors, it is possible to prevent the projector's configuration from becoming more complex and manufacturing costs from increasing.

[0097] [Note 14] In the projector described in Appendix 12 or Appendix 13, The housing has an injection hole into which the gas can be injected, The injection hole is provided on the intake side of the cooling fan. A projector characterized by the following features. With this configuration, when the cooling fan is running, the intake side of the cooling fan becomes negative pressure. Therefore, it is possible to suppress the leakage of the gas sealed inside the enclosure to the outside of the enclosure through the injection hole.

[0098] [Note 15] In the projector described in Appendix 14, The housing has a cover member that covers the injection hole. A projector characterized by the following features. With this configuration, the injection hole can be protected by the cover member. This prevents damage to the injection hole and prevents gas from leaking out of the housing from the injection hole.

[0099] [Note 16] In the projector described in any one of the appendices 1 through 15, The photosynthetic apparatus is, A first incident surface facing the first optical modulation element, A second incident surface intersects with the first incident surface and faces the second optical modulation element, A third incident surface located on the opposite side of the first incident surface and facing the third optical modulation element, It has an output surface located on the opposite side of the second incident surface and which emits the projected light, The first light source is positioned opposite the first optical modulation element, The second light source is positioned opposite the second optical modulation element, The third light source is positioned opposite the third optical modulation element, A projector characterized by the following features.

[0100] With this configuration, the first to third light sources in the light source device, the first to third light modulation elements in the light modulation device, and the photosynthesis device can be arranged compactly. Therefore, the projector can be miniaturized. In addition, this makes it easier to cool each light source and each light modulation element with the airflow generated by a single cooling fan. [Explanation of Symbols]

[0101] 1A, 1B…Projector, 2, 2B…Outer casing, 3…Inner casing, 37…Injection section, 371…Injection hole, 374…Cover member, 4…Projection light generation device, 41…Light source device, 41R…Red light source (first light source), 41G…Green light source (second light source), 41B…Blue light source (third light source), 44…Image forming device, 45…Light modulation device, 45R…Red light modulation element (first light modulation element), 45G…Green light modulation element (second light modulation element), 45B…Blue light modulation element (third light modulation element), 46…Photosynthesis device, 5…Cooling device, 51…Cooling fan, 52…Heat dissipation member, 52 R...Heat dissipation member for red (first heat dissipation member), 52G...Heat dissipation member for green (second heat dissipation member), 52B...Heat dissipation member for blue (third heat dissipation member), 53...Heat transport member, 53R...Heat transport member for red, 53G...Heat transport member for green, 53B...Heat transport member for blue, 54...Rectifier plate, 541...Flow section, 541R...Flow section for red, 541G...Flow section for green, 541B...Flow section for blue, 543...Opening, 543R...Opening for red, 543G...Opening for green, 543B...Opening for blue, 6A, 6B...Control device, 61...Monitor circuit, 62...Memory, 63...Processor, 64...Status acquisition unit.

Claims

1. A projection light generating device that generates projected light, A cooling fan generates an airflow through which the heat generated by the aforementioned projection light generating device is transferred, A heat dissipation member that releases the transferred heat into the airflow, The system comprises the aforementioned light projection device, the cooling fan, and the heat dissipation member, The aforementioned projection light generating device is A light source device having a first light source that emits first light, a second light source that emits second light, and a third light source that emits third light, An optical modulation device having a first optical modulation element for modulating the first light, a second optical modulation element for modulating the second light, and a third optical modulation element for modulating the third light, A photosynthetic apparatus that synthesizes the first light, second light, and third light modulated by the light modulation device, The cooling fan is positioned so as to overlap the projection light generating device and the heat dissipation member when viewed from a first direction perpendicular to the plane containing the optical axes of the first light, the second light, and the third light. The projection light generating device and the heat dissipation member are positioned with the cooling fan in the first direction, The cooling fan generates the airflow that flows in one of the first direction and the direction opposite to the first direction. A projector characterized by the following features.

2. In the projector according to claim 1, In the first direction, the projection light generating device is positioned between the cooling fan and a rectifier plate that rectifies the airflow, The aforementioned rectifier plate is A first opening is provided according to the first optical modulation element, through which a portion of the airflow passes, A second opening is provided according to the second optical modulation element, through which a portion of the airflow passes, A third opening is provided according to the third optical modulation element, through which a portion of the airflow passes, A projector characterized by the following features.

3. In the projector according to claim 2, The first light source is an LED that emits red light, which is the first light. The opening area of ​​the first opening is larger than the opening area of ​​the second opening and the opening area of ​​the third opening. The airflow flowing through the first opening flows along the first light source and the first light modulation element. A projector characterized by the following features.

4. In the projector according to any one of claims 1 to 3, The heat dissipation member is A first heat dissipation member thermally connected to the first light source, The system includes a second heat dissipation member provided independently of the first heat dissipation member and thermally connected to the second light source, A projector characterized by the following features.

5. In the projector according to claim 4, The third light source is thermally connected to the second heat dissipation member. A projector characterized by the following features.

6. In the projector according to claim 4, The heat dissipation member includes a third heat dissipation member that is provided independently of the first heat dissipation member and the second heat dissipation member and is thermally connected to the third light source. A projector characterized by the following features.

7. In the projector according to claim 4, The system includes a control device that controls the operation of the cooling fan, The control device switches the rotation direction of the cooling fan based on at least one of the temperature of the light source device, the cumulative operating time of the projection light generation device, and the illuminance of any of the first light, second light, third light, and projection light. A projector characterized by the following features.

8. In the projector according to any one of claims 1 to 3, The projection light generating device is housed in a sealed state within the housing. A projector characterized by the following features.

9. In the projector according to claim 8, The projection light generation device has a lens barrel that houses a lens, and includes a projection lens that projects the projection light synthesized by the photosynthesis device. The aforementioned enclosure is The opening through which the projected light passes, The device includes a sealing member that seals the opening while a part of the lens barrel is positioned inside the opening. A projector characterized by the following features.

10. In the projector according to claim 9, The system includes an outer casing that houses the aforementioned housing and the projection lens, and constitutes the outer casing. A projector characterized by the following features.

11. In the projector according to claim 9, The aforementioned enclosure is an outer enclosure that constitutes the exterior. A projector characterized by the following features.

12. In the projector according to any one of claims 1 to 3, The enclosure contains a gas having a higher thermal conductivity than that of air. A projector characterized by the following features.

13. In the projector according to claim 12, The system includes a monitoring circuit that monitors the rotation speed of the cooling fan, The aforementioned gas is helium gas. A projector characterized by the following features.

14. In the projector according to claim 12, The housing has an injection hole into which the gas can be injected, The injection hole is provided on the intake side of the cooling fan. A projector characterized by the following features.

15. In the projector according to claim 14, The housing has a cover member that covers the injection hole. A projector characterized by the following features.

16. In the projector according to any one of claims 1 to 3, The photosynthetic apparatus is, A first incident surface facing the first optical modulation element, A second incident surface intersects with the first incident surface and faces the second optical modulation element, A third incident surface located on the opposite side of the first incident surface and facing the third optical modulation element, It has an output surface located on the opposite side of the second incident surface and which emits the projected light, The first light source is positioned opposite the first optical modulation element, The second light source is positioned opposite the second optical modulation element, The third light source is positioned opposite the third optical modulation element, A projector characterized by the following features.

Images