Projector

Abstract

To provide a projector that can prevent the occurrence of color irregularities.SOLUTION: A projector comprises: an image forming apparatus that has a liquid crystal panel, an incident side polarizing plate provided on a light incident side relative to the liquid crystal panel, and a first channel provided between the liquid crystal panel and the incident side polarizing plate, and that forms image light; a light source device that emits light incident on the image forming apparatus; a projection optical device that projects image light emitted from the image forming apparatus; a first fan that circulates an air current through the first channel; and a first rectification unit that is provided upstream of the air current relative to the liquid crystal panel, and rectifies the air current circulating through the first channel toward the incident side polarizing plate.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a projector. [Background technology]

[0002] Conventionally, there has been known a projector that modulates light emitted from a light source to form image light according to image information, and projects the formed image light onto a projection surface. As such a projector, there is known an image projection device that modulates light emitted from a color illumination device by a single image generating means (see, for example, Patent Document 1). In the image projection device described in Patent Document 1, the image generation means is composed of, for example, a transmissive liquid crystal display element. White light emitted from a color illumination device is separated into red, green, and blue light, and the separated red, green, and blue light are incident in a repeated order on three regions that divide the effective area of ​​the image generation means into thirds. The image generation means generates an image from the incident color light, and the generated image is projected by a projection lens unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-310035 Summary of the Invention [Problem to be solved by the invention]

[0004] Projectors equipped with a single image generating unit such as a liquid crystal panel, such as the image projection device described in Patent Document 1, are easily made compact and are therefore used for mobile applications. In such projectors, the image generating unit is generally cooled by cooling gas circulated by a fan or the like. However, when cooling gas is circulated from one end of the image generating means to the other end along the effective area of ​​the image generating means, the temperature of the portion of the effective area at one end where the cooling gas flows, which has a lower temperature, tends to be lower.On the other hand, since the cooling gas absorbs heat as it flows along the effective area to the other end, the temperature of the cooling gas circulating in the portion at the other end of the effective area tends to be higher, and the temperature of the portion at the other end of the effective area tends to be higher. In this way, when cooling gas is circulated from one end of the image generating means to the other along the effective area, uneven cooling is likely to occur in the effective area, and temperature differences in the effective area are likely to increase. In such cases, the temperature differences can cause thermal distortion in the effective area, degrading the optical characteristics of the image generating means and potentially causing color unevenness in the formed image light. For this reason, there has been a demand for a projector configuration that can suppress the occurrence of color unevenness. [Means for solving the problem]

[0005] A projector according to one aspect of the present disclosure includes an image forming device having a liquid crystal panel, an incident side polarizing plate provided on the light incident side of the liquid crystal panel, and a first flow path provided between the liquid crystal panel and the incident side polarizing plate, and forming image light; a light source device that emits light incident on the image forming device; a projection optical device that projects the image light emitted from the image forming device; a first fan that circulates airflow through the first flow path; and a first rectification unit that is provided upstream of the airflow relative to the liquid crystal panel and rectifies the airflow flowing through the first flow path toward the incident side polarizing plate. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view showing a projector according to a first embodiment. [Figure 2] FIG. 1 is a perspective view showing a projector according to a first embodiment. [Figure 3] FIG. 1 is a diagram showing the internal structure of a projector according to a first embodiment. [Figure 4]FIG. 1 is a schematic diagram showing the configuration of an image projection device and a cooling device according to a first embodiment. [Figure 5] FIG. 1 is a perspective view showing an image projection device and a cooling device according to a first embodiment. [Figure 6] FIG. 1 is a perspective view showing an image projection device and a cooling device according to a first embodiment. [Figure 7] 4A and 4B are diagrams showing airflows rectified by a rectifying unit according to the first embodiment. [Figure 8] FIG. 4 is a schematic diagram showing a modification of the image projection device according to the first embodiment. [Figure 9] 10A and 10B are schematic diagrams showing parts of an image projection device and a cooling device included in a projector according to a second embodiment. [Figure 10] FIG. 10 is a schematic diagram showing an image projection device and a cooling device provided in a projector according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] [First embodiment] Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings. [Projector configuration] FIG. 1 is a perspective view of a projector 1 according to this embodiment as seen from the front side, and FIG. 2 is a perspective view of the projector 1 as seen from the rear side. A projector 1 according to this embodiment is an image display device that modulates light emitted from a light source to form image light according to image information, and projects the formed image light onto a projection surface. As shown in FIGS. 1 and 2, the projector 1 includes an exterior housing 2.

[0008] [Exterior casing configuration] The exterior housing 2 constitutes the exterior of the projector 1. The exterior housing 2 accommodates an image projection device 3A (described later) inside. The exterior housing 2 has a housing main body 20 and a stand . In the following description, the three mutually perpendicular directions are referred to as the +X direction, the +Y direction, and the +Z direction. In this embodiment, the +Z direction is the direction from the back surface portion 22 toward the front surface portion 21, the +Y direction is the direction from the bottom surface portion 24 toward the top surface portion 23, and the +X direction is the direction from the left side surface portion 25 toward the right side surface portion 26. Although not shown in the figures, the direction opposite the +X direction is referred to as the -X direction, the direction opposite the +Y direction is referred to as the -Y direction, and the direction opposite the +Z direction is referred to as the -Z direction. The axis along the +X direction is referred to as the X axis, the axis along the +Y direction is referred to as the Y axis, and the axis along the +Z direction is referred to as the Z axis.

[0009] [Configuration of the main body] The housing body 20 has a front surface 21, a rear surface 22, a top surface 23, a bottom surface 24, a left side surface 25, and a right side surface 26. The front surface 21 and the rear surface 22 are surfaces facing in opposite directions. The front surface 21 faces the +Z direction, and the rear surface 22 faces the -Z direction. As shown in FIG. 1, the front portion 21 has a projection port 211 and an introduction port 212. The projection aperture 211 is an opening that exposes the end portion on the light emission side of the projection optical device 40 that the image projection device 3A has. The image light projected from the projection optical device 40 passes through the projection aperture 211. The inlet 212 is provided in the −Y direction with respect to the projection port 211. The inlet 212 is an opening that introduces gas outside the exterior housing 2 as cooling gas into the interior of the exterior housing 2. Although not shown, the inlet 212 is provided with a filter that collects dust.

[0010] 2, the rear surface portion 22 has an exhaust port 221 extending along the Y axis. The exhaust port 221 exhausts the airflow that has circulated inside the exterior housing 2 and cooled the object to be cooled to the outside of the exterior housing 2.

[0011] 1 and 2, the top surface portion 23 and the bottom surface portion 24 are surfaces facing in opposite directions to each other. The top surface portion 23 faces the +Y direction, and the bottom surface portion 24 faces the -Y direction. The left side surface portion 25 and the right side surface portion 26 are surfaces facing in opposite directions. The left side surface portion 25 faces the -X direction, and the right side surface portion 26 faces the +X direction. The left side surface portion 25 has an attachment portion 251 to which the stand 28 is attached, and the right side surface portion 26 has a similar attachment portion 261.

[0012] [Stand configuration] The stand 28 supports the housing body 20 so that the orientation of the housing body 20 in the YZ plane can be adjusted. In other words, the stand 28 supports the housing body 20 so that the projection direction of the image light can be adjusted. The stand 28 has an installation portion 281, standing portions 282 and 283, and a connector 284. 2, the installation section 281 is formed in a substantially rectangular shape, and a bottom surface 2811 of the installation section 281 facing the -Y direction faces the installation surface on which the projector 1 is installed. A top surface 2812 of the installation section 281 facing the +Y direction and the bottom surface section 24 are spaced apart from each other. The standing portion 282 stands in the +Y direction from the edge of the top surface 2812 in the -X direction, and the standing portion 283 stands in the +Y direction from the edge of the top surface 2812 in the +X direction. Each of the standing portions 282, 283 is formed in a substantially isosceles triangle shape when viewed from the +X direction. Although not shown, the standing portion 283 has an insertion hole through which a part of the connector 284 is inserted along the X axis.

[0013] 2, the connector 284 connects the stand 28 and the housing main body 20. The connector 284 is inserted through the insertion opening of the standing portion 283 in the −X direction and fixed to the right side surface portion 26, thereby connecting the stand 28 to the housing main body 20. It should be noted that even without the stand 28, the projector 1 can still project an image.

[0014] [Projector internal structure] Fig. 3 is a diagram showing the internal structure of the projector 1. In other words, Fig. 3 is a diagram showing a cross section of the projector 1 along the YZ plane as viewed from the +X direction. 3, the projector 1 includes an image projection device 3A, a cooling device 5, and a control device and a power supply device (not shown). The image projection device 3A, the cooling device 5, the control device, and the power supply device are housed in an exterior housing 2. The control device controls the operation of the projector 1 , and the power supply device supplies power to the electronic components that make up the projector 1 .

[0015] [Configuration of image projection device] FIG. 4 is a schematic diagram showing the configuration of the image projection device 3A and the cooling device 5. As shown in FIG. The image projection device 3A generates and projects image light in accordance with an image signal input from a control device. As shown in Figures 3 and 4, the image projection device 3A includes a light source device 31, a reflector 32, an image forming device 33, an optical path changing member 39, a projection optical device 40, and an optical component housing 41A.

[0016] [Light source configuration] Light source device 31 emits white light in the +Y direction to be incident on image forming device 33. More specifically, light source device 31 emits white light containing p-polarized light and s-polarized light. Light source device 31 has a light-emitting section 311, a supporting substrate 312, and a heat dissipation member 313. The light-emitting unit 311 is configured to include at least one light-emitting element, and the light-emitting element is configured by a solid-state light source such as an LED (Light Emitting Diode). The light-emitting unit 311 is mounted on a support substrate 312. The light-emitting unit 311 is disposed at a position closer to the bottom surface unit 24 than the projection optical device 40, and emits white light in the +Y direction. The reflector 32, the image forming device 33, and the optical path changing member 39 are disposed on the optical path of the white light emitted from the light-emitting unit 311. The support substrate 312 not only supports the light emitting section 311 but also supplies power to the light emitting section 311 . Heat dissipation member 313 is provided on the side of support substrate 312 opposite to the surface on which light emitting unit 311 is mounted. Heat dissipation member 313 dissipates heat from light emitting unit 311 transferred from support substrate 312. Specifically, heat dissipation member 313 dissipates the heat from light emitting unit 311 transferred to an airflow circulating from second fan 52 of cooling device 5, which will be described later.

[0017] [Reflector configuration] The reflector 32 aligns the traveling direction of the light emitted from the light source device 31. The reflector 32 and the light source device 31 are connected to each other so as to prevent light leakage. The same applies to the reflector 32 and the incident-side lens 34. The reflector 32 may be one of a quadrangular pyramid-shaped reflector, an ellipsoidal reflector having an ellipsoid of revolution, and a paraboloidal reflector having a paraboloid of revolution. The reflector 32 may also be a hollow reflector having an internal space, or a solid reflector filled with a light-transmitting material.

[0018] [Configuration of image forming device] The image forming device 33 modulates the white light incident from the light source device 31 via the reflector 32 in accordance with an image signal input from a control device (not shown) to form color image light. That is, the image forming device 33 modulates the white light emitted from the light source device 31 based on the image signal to form full-color image light. In this embodiment, the projector 1 includes one image forming device 33. In other words, the image projection device 3A includes one image forming device 33. The image forming device 33 has an incident-side lens 34 , an incident-side polarizing plate 35 , a liquid crystal panel 36 , an exit-side polarizing plate 37 , and an exit-side lens 38 .

[0019] [Input lens configuration] The incident-side lens 34 focuses light emitted from the light source device 31 and incident via the reflector 32 onto the incident-side polarizing plate 35. That is, the incident-side lens 34 is provided on the light incident side of the incident-side polarizing plate 35. The incident-side lens 34 is made of a Fresnel lens, and effectively expands the diameter of the incident light over a short distance. That is, the incident-side lens 34 is a first Fresnel lens.

[0020] [Configuration of incident side polarizer] The incident-side polarizing plate 35 is disposed at a distance from the incident-side lens 34 to the light-exiting side of the incident-side lens 34, and at a distance from the liquid crystal panel 36 to the light-incident side of the liquid crystal panel 36. That is, the incident-side lens 34 and the incident-side polarizing plate 35 are spaced apart from each other along the Y axis, and the incident-side polarizing plate 35 and the liquid crystal panel 36 are spaced apart from each other along the Y axis. Incident-side polarizing plate 35 transmits the first linearly polarized light and blocks the second linearly polarized light among the light incident from incident-side lens 34. Of the first linearly polarized light and the second linearly polarized light, one of the linearly polarized light is p-polarized light, and the other linearly polarized light is s-polarized light. In this embodiment, to simplify the configuration of the projector 1, the light source device 31 emits light including p-polarized light and s-polarized light. Therefore, if the incident-side polarizing plate 35 absorbs the second linearly polarized light, heat is generated by the white light emitted from the light source device 31 entering the incident-side polarizing plate 35. As such, the incident-side polarizing plate 35 is one of the heat sources of the projector 1. The incident-side polarizing plate 35 may reflect the incident second linearly polarized light rather than absorbing it. That is, the incident-side polarizing plate 35 transmits the first linearly polarized light and reflects the second linearly polarized light, thereby suppressing heat generation in the incident-side polarizing plate 35. Furthermore, the polarization direction of the second linearly polarized light may be rotated by repeated reflections, and the second linearly polarized light may be converted into the first linearly polarized light. Therefore, by returning the second linearly polarized light reflected by the incident-side polarizing plate 35 to the light source device 31 via the reflector 32, the first linearly polarized light converted from the second linearly polarized light can be emitted from the light source device 31, and the second linearly polarized light can be recycled.

[0021] As shown in FIG. 4, the incident-side polarizing plate 35 has a light incident surface 351 facing the incident-side lens 34 and a light exit surface 352 opposite to the light incident surface 351. A second flow path F2 through which air can flow along the -Z direction is provided between the light incident surface 351 and the incident-side lens 34. That is, the image forming device 33 has the second flow path F2. The second flow path F2 corresponds to the incident-side flow path. A first flow path F1 through which air can flow along the -Z direction is provided between the light exit surface 352 and the light entrance surface 361 of the liquid crystal panel 36. That is, the image forming device 33 has the first flow path F1.

[0022] [LCD panel configuration] 3 and 4, white light is incident on the liquid crystal panel 36 from the incident-side polarizing plate 35, and the liquid crystal panel 36 modulates the incident white light in accordance with an image signal. As shown in FIG. 4, the liquid crystal panel 36 has a light incident surface 361 and a light exit surface 362. The light incident surface 361 is a plane perpendicular to the Y axis and faces the light exit surface 352 of the incident-side polarizing plate 35. White light is incident on the light incident surface 361 from the incident-side polarizing plate 35. As described above, the first flow path F1 is provided between the light incident surface 361 and the light exit surface 352 of the incident-side polarizing plate 35. Light exit surface 362 is a plane perpendicular to the Y axis, and is the surface of liquid crystal panel 36 opposite to light entrance surface 361. Light modulated by liquid crystal panel 36 exits from light exit surface 362. Although detailed illustrations are omitted, such a liquid crystal panel 36 has one transmissive liquid crystal element and one color filter, and is configured by combining a transmissive liquid crystal element arranged on the light incident side with a color filter arranged on the light exit side.

[0023] The transmissive liquid crystal element generates heat due to the incidence of light and the supply of power. The liquid crystal contained in the transmissive liquid crystal element also deteriorates due to heat. For this reason, the liquid crystal panel 36 including the transmissive liquid crystal element is one of the heat sources in the projector 1 that needs to be cooled. The color filter is disposed on the light exit surface of the transmissive liquid crystal element. The color filter has a plurality of filter elements disposed in accordance with one pixel constituted by the transmissive liquid crystal element. The filter elements are constituted by a red filter, a green filter, and a blue filter, and the red filter, the green filter, and the blue filter are disposed in accordance with the sub-pixels of the corresponding pixel. The red filter is a filter that transmits red light, the green filter is a filter that transmits green light, and the blue filter is a filter that transmits blue light. However, the color filters are not limited to the above filters, and may be monochromatic filters provided for each pixel.

[0024] [Configuration of output polarizer] 4, the output-side polarizing plate 37 is fixed to the liquid crystal panel 36 in contact with the light output surface 362 of the liquid crystal panel 36. That is, the output-side polarizing plate 37 is in contact with the light output surface of the color filter of the liquid crystal panel 36. The output-side polarizing plate 37 is disposed at a distance from the output-side lens 38 on the light incident side of the output-side lens 38.

[0025] When the polarization transmission axis of the exit-side polarizer 37 and the polarization transmission axis of the entrance-side polarizer 35 are perpendicular to each other, the exit-side polarizer 37 transmits light modulated by the liquid crystal panel 36 and absorbs light not modulated by the liquid crystal panel 36. When the polarization transmission axis of the exit-side polarizer 37 and the polarization transmission axis of the entrance-side polarizer 35 are parallel to each other, the exit-side polarizer 37 absorbs light modulated by the liquid crystal panel 36 and transmits light not modulated by the liquid crystal panel 36. For this reason, the exit-side polarizer 37 is also one of the heat sources of the projector 1. A third flow path F3 through which air can flow along the -Z direction is provided between the light exit surface 372 of the exit-side polarizing plate 37 and the exit-side lens 38 provided on the light exit side of the exit-side polarizing plate 37. That is, the image forming device 33 has the third flow path F3. The third flow path F3 corresponds to the exit-side flow path.

[0026] [Output lens configuration] 3 and 4, the output-side lens 38 is disposed away from the output-side polarizing plate 37 on the light output side of the output-side polarizing plate 37. The output-side lens 38 collects the image light output from the output-side polarizing plate 37 and makes it incident on the optical path changing member 39. The output-side lens 38 is made of a Fresnel lens. In other words, the output-side lens 38 is a second Fresnel lens.

[0027] [Configuration of optical path changing component] The optical path changing member 39 is disposed in the optical path of the image light between the output lens 38 and the projection optical device 40. In other words, the optical path changing member 39 is constituted by a reflecting mirror disposed in the optical path of the image light between the image forming device 33 and the projection optical device 40. The optical path changing member 39 changes the traveling direction of the image light incident from the output side lens 38 by 90°, and guides the image light to the projection optical device 40 .

[0028] [Configuration of the projection optical device] The projection optical device 40 projects the image light incident from the optical path changing member 39. As shown in Fig. 3, the projection optical device 40 can be configured as a lens assembly including a plurality of lenses 401 and a lens barrel 402 that houses the plurality of lenses 401. A portion of the projection optical device 40 on the light output side is connected to the exterior housing 2, and the portion of the projection optical device 40 on the light output side is exposed to the outside of the exterior housing 2, while the portion of the light input side is housed in the exterior housing 2.

[0029] [Configuration of optical component housing] FIG. 5 is a perspective view of the image projection device 3A and the cooling device 5 as viewed from the +Z direction, and FIG. 6 is a perspective view of the image projection device 3A and the cooling device 5 as viewed from the -Z direction. As shown in Fig. 3, the optical component casing 41A accommodates the light source device 31, the reflector 32, the image forming device 33, and the optical path changing member 39. As shown in Figs. 3 to 6, the optical component casing 41A has a first accommodating section 42, a second accommodating section 43, a third accommodating section 44, a first duct section 45, and a second duct section 46. In this embodiment, the optical component casing 41A has the sections 42 to 46 integrally configured, but some of the sections 42 to 46 may be separated.

[0030] [Configuration of the first storage section] The first housing section 42 houses the light source device 31, the reflector 32, and the incident-side lens 34. Although not shown in detail, an opening that communicates between the inside and outside of the first housing section 42 is formed on each of the end faces in the -Y direction and the +Y direction of the first housing section 42. The opening in the -Y direction is closed by the heat dissipation member 313 of the light source device 31. The opening in the +Y direction is closed by the incident-side lens 34.

[0031] [Configuration of the second storage section] The second housing section 43 is provided between the first housing section 42 and the third housing section 44 on the Y axis. The second housing section 43 is a cylindrical section that supports the incident-side polarizing plate 35, the liquid crystal panel 36, the exit-side polarizing plate 37, and the exit-side lens 38, and is configured to allow airflow to flow inside in the -Z direction. More specifically, the second housing section 43 is configured to allow airflow sent out from a first fan 51 of the cooling device 5, which will be described later, to flow inside, and the first flow path F1, the second flow path F2, and the third flow path F3 described above are provided inside the second housing section 43.

[0032] As shown in FIGS. 3 and 4, the second accommodating section 43 has an opening 431 that opens in the +Z direction and an opening 432 that opens in the −Z direction. The opening 431 is an opening that connects the inside of the second housing portion 43 with the inside of the first duct portion 45, and is an inlet portion that allows the airflow sent out from the first fan 51 to flow into the second housing portion 43. In other words, the opening 431 allows the airflow sent out from the first fan 51 to flow through each of the flow paths F1 to F3. The opening 432 is an opening that connects the inside of the second housing portion 43 with the inside of the second duct portion 46, and is an outlet portion that causes the airflow that has flowed inside the second housing portion 43 to flow out of the second housing portion 43. In other words, the opening 432 causes the airflow that has flowed through each of the flow paths F1 to F3 to flow out to the second duct portion 46.

[0033] As will be described in detail later, the airflow sent out from the first fan 51 flows through the flow paths F1 to F3 provided in the second housing portion 43 via the opening 431, and cools the entrance-side polarizing plate 35, the liquid crystal panel 36, and the exit-side polarizing plate 37. The airflow that has flowed through the flow paths F1 to F3 is then discharged from the opening 432 to the second duct 46. Furthermore, the second accommodation section 43 has a first rectifying section 433, a second rectifying section 434, and a third rectifying section 435 that rectify the airflow circulated by the first fan 51. The rectifying sections 433 to 435 will be described in detail later.

[0034] [Configuration of the third storage section] 3 and 4 , the third housing portion 44 is connected to the second housing portion 43 and houses the optical path changing member 39. The third housing portion 44 has openings provided on each of the end face in the −Y direction and the end face in the +Z direction, which communicate between the inside and outside of the third housing portion 44. The opening in the −Y direction allows the image light emitted from the output-side lens 38 to be incident on the optical path changing member 39. The opening in the +Z direction allows the image light reflected by the optical path changing member 39 to be incident on the projection optical device 40.

[0035] [Configuration of the first duct section and the second duct section] 3 to 6, the first duct portion 45 is provided in the +Z direction relative to the first housing portion 42 and the second housing portion 43, and is connected to the first housing portion 42 and the second housing portion 43. As shown in FIG. 3, the first duct portion 45 connects the inlet 212 provided in the front portion 21 to the second housing portion 43, and communicates the inlet 212 with the opening portion 431. A first fan 51 is arranged inside the first duct portion 45. As shown in FIGS. 3 to 6 , the second duct portion 46 is provided in the −Z direction relative to the first housing portion 42 and the second housing portion 43 and is connected to the first housing portion 42 and the second housing portion 43. As shown in FIG. 3 , the second duct portion 46 connects the second housing portion 43 to the exhaust port 221 provided in the rear surface portion 22 and communicates between the opening 432 of the second housing portion 43 and the exhaust port 221. Therefore, the airflow that has flowed through each of the flow paths F1 to F3 in the second housing portion 43 flows through the second duct portion 46 and is discharged from the exhaust port 221 to the outside of the exterior housing 2. Note that a louver 461 is provided in the second duct portion 46 to rectify the airflow discharged to the exhaust port 221 and to prevent leaked light from the image forming device 33 from being emitted from the exhaust port 221.

[0036] [Cooling system configuration] The cooling device 5 cools the light source device 31 and the image forming device 33, which are heat sources, by circulating airflow through them. The cooling device 5 has a first fan 51 as shown in FIGS. 3 to 5, and also has a second fan 52 as shown in FIGS. 3 and 6.

[0037] [Second fan configuration] The second fan 52 is disposed in the −Y direction relative to the first duct portion 45. As shown in FIG. 3 , the second fan 52 sucks in a portion of the cooling gas introduced into the interior of the exterior housing 2 through the inlet 212 and sends out the airflow in the −Z direction. The sent-out airflow flows through the heat dissipation member 313 located in the −Z direction relative to the second fan 52. As a result, the heat of the light-emitting unit 311 transferred to the heat dissipation member 313 is transferred to the airflow, thereby cooling the light-emitting unit 311. The airflow that has flowed through the heat dissipation member 313 flows in the +Y direction along the inner surface of the exterior housing 2 and is discharged to the outside of the exterior housing 2 through the outlet 221 provided in the rear surface portion 22.

[0038] [Configuration of the first fan] 3, the first fan 51 draws in outside air from the exterior housing 2 through the inlet 212 and distributes the air inside the second housing section 43. The first fan 51 is configured by a centrifugal fan such as a sirocco fan, and has intake sections 511 and 512 and a delivery section 513 as shown in FIGS. The intake sections 511 and 512 are provided on opposite sides of the first fan 51. The intake sections 511 and 512 draw ambient gas into the first fan 51. In other words, the first fan 51 is a double-sided intake centrifugal fan having the two intake sections 511 and 512. However, the first fan 51 may also be a single-sided intake centrifugal fan having only the intake section 511. The delivery section 513 is provided on a side surface that intersects with the surface on which the intake section 511 is provided and the surface on which the intake section 512 is provided. The delivery section 513 delivers the cooling gas sucked into the inside of the first fan 51. The delivery section 513 delivers the cooling gas toward the second accommodation section 43, thereby causing an airflow to circulate inside the second accommodation section 43.

[0039] Fig. 7 is a diagram showing a cross section of the image forming device 33, the second housing section 43, and the first fan 51 along the YZ plane. In other words, Fig. 7 is a diagram showing the airflow rectified by the rectification sections 433 to 435. Note that in Fig. 7, part of the airflow is indicated by a solid line. 7, the first fan 51 causes the airflow to flow toward the opening 431 of the second housing section 43. In other words, the first fan 51 causes the airflow to flow toward the image forming device 33 arranged in the second housing section 43. The first fan 51 is disposed so that the airflow blowing direction D1 from the blowing section 513 is inclined with respect to the Y-axis and Z-axis. More specifically, the first fan 51 is disposed so that the blown airflow flows in the +Y direction as it heads in the -Z direction. That is, the first fan 51 is disposed so that the airflow blowing direction D1 from the blowing section 513 intersects with the extension plane EP of the light incident surface 361 of the liquid crystal panel 36, when viewed from the +X direction. The airflow blown out from the blowing section 513 of the first fan 51 flows through the flow paths F1 to F3 provided in the second housing section 43 via the opening 431. At this time, the airflow blown out from the blowing section 513 flows through the flow paths F1 to F3 after being rectified by the rectification sections 433 to 435 provided in the second housing section 43.

[0040] [Airflow straightening by the straightening section] As described above, the second container 43 has the first rectifying section 433, the second rectifying section 434, and the third rectifying section 435. Each of the rectifying sections 433 to 435 is provided upstream of the airflow relative to each of the flow paths F1 to F3.

[0041] [Configuration and Function of First Rectification Unit] The first rectification section 433 is provided upstream of the airflow relative to the first flow path F1 provided between the incident-side polarizing plate 35 and the liquid crystal panel 36. Specifically, the first rectification section 433 is provided upstream of the airflow relative to the liquid crystal panel 36. More specifically, the first rectification section 433 is provided at a position in the +Z direction relative to the liquid crystal panel 36. The first rectification section 433 is formed in a substantially triangular prism shape when viewed from the +X direction. The first rectification section 433 has an inclined section 4331 that protrudes from the end in the +Z direction toward the liquid crystal panel 36 and toward the incident-side polarizing plate 35. The first rectifying section 433 directs the airflow flowing through the first flow path F1 toward the incident-side polarizing plate 35. More specifically, the first rectifying section 433 guides the airflow to a portion of the light exit surface 352 of the incident-side polarizing plate 35 that is on the upstream side of the airflow.

[0042] 7, most of the airflow sent out from the delivery unit 513 and flowing through the first flow path F1 flows along the inclined portion 4331, thereby flowing through the first flow path F1 toward the incident-side polarizing plate 35. The airflow that has been rectified by the inclined portion 4331 and flows toward the incident-side polarizing plate 35 collides with the incident-side polarizing plate 35, flows in the -Z direction, and also comes into contact with the light incident surface 361 of the liquid crystal panel 36. This causes the airflow to flow along the incident-side polarizing plate 35 and the liquid crystal panel 36. In addition, a portion of the airflow flowing through the first flow path F1 flows along the inclined portion 4331, and then generates a swirling flow at the intersection between the first straightening portion 433 and the liquid crystal panel 36, cooling the upstream portion of the liquid crystal panel 36, i.e., the end portion in the +Z direction of the light incident surface 361 of the liquid crystal panel 36.

[0043] In this way, the flow rate of the airflow flowing through the first flow path F1 is reduced in the upstream portion of the light incident surface 361 of the liquid crystal panel 36. On the other hand, because the flow rate of the airflow flowing through the upstream portion of the first flow path F1 is reduced, the temperature rise of the airflow flowing through the downstream portion of the first flow path F1 is suppressed even if the airflow flows along the incident-side polarizing plate 35 and the liquid crystal panel 36, which are the objects to be cooled. Therefore, compared to when the first rectification section 433 is not provided, the cooling efficiency of the upstream portion of the liquid crystal panel 36 through which a relatively low temperature airflow flows is lower, and the cooling efficiency of the downstream portion of the liquid crystal panel 36 through which a relatively high temperature airflow flows is higher. This makes it possible to reduce the temperature difference on the light incident surface 361 of the liquid crystal panel 36, and suppress the occurrence of uneven cooling of the liquid crystal panel 36.

[0044] [Configuration and operation of the second rectifying section] The second rectification section 434 is provided upstream of the airflow relative to the second flow path F2 provided between the incident-side lens 34 and the incident-side polarizing plate 35. Specifically, the second rectification section 434 is provided upstream of the airflow relative to the incident-side polarizing plate 35. More specifically, the second rectification section 434 is provided at a position in the +Z direction relative to the incident-side polarizing plate 35. The +Z direction end of the second rectification section 434 comes into contact with the delivery section 513 of the first fan 51. Similar to the inclined section 4331 of the first rectification section 433, the second rectification section 434 has an inclined section 4341 that protrudes from the +Z direction end toward the incident-side polarizing plate 35 and toward the incident-side lens 34. The second rectifying section 434 directs the airflow flowing through the second flow path F2 toward the incident-side lens 34. More specifically, the second rectifying section 434 guides the airflow to a portion of the light exit surface of the incident-side lens 34 on the upstream side of the airflow.

[0045] 7, most of the airflow that is sent out from the sending-out unit 513 and flows through the second flow path F2 flows along the inclined portion 4341, thereby flowing through the second flow path F2 toward the incident-side lens 34. The airflow that flows toward the incident-side lens 34 collides with the incident-side lens 34, flows in the -Z direction, and comes into contact with the light incident surface 351 of the incident-side polarizing plate 35. This causes the airflow to flow along the incident-side lens 34 and the incident-side polarizing plate 35. In addition, a portion of the airflow flowing through the second flow path F2 flows along the inclined portion 4341, and then generates a swirling flow at the intersection between the second straightening portion 434 and the incident side polarizing plate 35, cooling the upstream portion of the incident side polarizing plate 35, i.e., the end portion in the +Z direction of the light incident surface 351 of the incident side polarizing plate 35.

[0046] In this way, of the airflow flowing through the second flow path F2, the flow rate of the airflow flowing through the upstream portion of the second flow path F2 at the light incident surface 351 of the incident-side polarizing plate 35 is reduced. On the other hand, because the flow rate of the airflow flowing through the upstream portion of the second flow path F2 is reduced, the temperature rise of the airflow flowing through the downstream portion of the second flow path F2 is suppressed even if the airflow flows along the incident-side polarizing plate 35, which is the target to be cooled. Therefore, compared to when second rectification section 434 is not provided, the cooling efficiency of the upstream portion of incident-side polarizing plate 35, through which air of a relatively low temperature flows, is lower, and the cooling efficiency of the downstream portion of incident-side polarizing plate 35, through which air of a relatively high temperature flows, is higher. This makes it possible to reduce the temperature difference on light incident surface 351 of incident-side polarizing plate 35, and suppress the occurrence of uneven cooling of incident-side polarizing plate 35.

[0047] [Configuration and operation of the third rectifier] The third rectification unit 435 is provided upstream of the airflow relative to the third flow path F3 provided between the output-side polarizing plate 37 and the output-side lens 38. Specifically, the third rectification unit 435 is provided upstream of the airflow relative to the output-side lens 38. More specifically, the third rectification unit 435 is provided at a position in the +Z direction relative to the output-side lens 38. An end portion of the third rectification section 435 in the +Z direction extends toward the first fan 51 and comes into contact with the surface of the first fan 51 on which the intake section 511 is provided. Similar to the inclined portion 4331 of the first rectification section 433, the third rectification section 435 has an inclined portion 4351 that protrudes from the contact portion with the first fan 51 toward the output-side polarizing plate 37 as it moves toward the output-side lens 38. The third rectification section 435 directs the airflow flowing through the third flow path F3 toward the exit-side polarizing plate 37. More specifically, the third rectification section 435 guides the airflow to the center of the light exit surface 372 of the exit-side polarizing plate 37, where the amount of heat generated is the highest. For this reason, as will be described in detail later, the protrusion dimension of the third rectification section 435 into the third flow path F3 is greater than the protrusion dimension of the first rectification section 433 into the first flow path F1.

[0048] 7, most of the airflow that is sent out from the delivery section 513 and flows through the third flow path F3 flows along the inclined portion 4351, thereby flowing through the third flow path F3 toward the output-side polarizing plate 37, which is a heat source. The airflow that flows toward the output-side polarizing plate 37 collides with the output-side polarizing plate 37 and flows in the -Z direction, while coming into contact with the light output surface 372 of the output-side polarizing plate 37. This causes the airflow to flow along the output-side polarizing plate 37 and the output-side lens 38. In addition, a portion of the airflow flowing through the third flow path F3 flows along the inclined portion 4351, and then generates a swirling flow at the intersection of the third straightening portion 435 and the exit side lens 38, cooling the upstream portion of the exit side lens 38, i.e., the end portion in the +Z direction of the light incident surface 381 of the exit side lens 38.

[0049] In this way, of the airflow flowing through the third flow path F3, the flow rate of the airflow flowing through the upstream portion of the third flow path F3 at the light exit surface 372 of the exit-side polarizing plate 37 is reduced. On the other hand, because the flow rate of the airflow flowing through the upstream portion of the third flow path F3 is reduced, the temperature rise of the airflow flowing through the downstream portion of the third flow path F3 is suppressed even if the airflow flows along the exit-side polarizing plate 37, which is the target to be cooled. Therefore, compared to when the third rectification section 435 is not provided, the cooling efficiency of the upstream portion of the exit-side polarizing plate 37 through which a relatively low-temperature airflow flows is lower, and the cooling efficiency of the downstream portion of the exit-side polarizing plate 37 through which a relatively high-temperature airflow flows is higher. This makes it possible to reduce the temperature difference on the light exit surface 372 of the exit-side polarizing plate 37, and suppress the occurrence of uneven cooling of the exit-side polarizing plate 37.

[0050] Here, the flow rate of the airflow sent out from the send-out portion 513 is greatest at the center of the send-out portion 513 and decreases toward the ends of the send-out portion 513. An imaginary line VL that passes through the center of the send-out portion 513 and is along the send-out direction D1 of the airflow from the send-out portion 513 intersects with the inclined portion 4331 of the first rectification portion 433. This allows a large amount of airflow to circulate through the first flow path F1 to which the liquid crystal panel 36 is exposed. Therefore, the cooling efficiency of the entire liquid crystal panel 36 can be improved. On the other hand, the flow path width of the third flow path F3 is larger than the flow path width of the first flow path F1. In other words, the dimension along the Y axis between the output-side polarizing plate 37 and the output-side lens 38 is larger than the dimension along the Y axis between the input-side polarizing plate 35 and the liquid crystal panel 36. The protrusion dimension of the third rectifying section 435 into the third flow path F3 is larger than the protrusion dimension of the first rectifying section 433 into the first flow path F1 and larger than the protrusion dimension of the second rectifying section 434 into the second flow path F2. This allows the airflow sent out from the region on one end side of the delivery section 513, where the delivery flow rate is low, to be taken in more into the third flow path F3, thereby ensuring the flow rate of the airflow cooling the output-side polarizing plate 37. This improves the cooling efficiency of the output-side polarizing plate 37 as a whole.

[0051] As described above, it is possible to suppress uneven cooling of the incident-side polarizing plate 35, the liquid crystal panel 36, and the exit-side polarizing plate 37, which are the targets to be cooled by the cooling device 5, and therefore it is possible to suppress uneven temperature variations in each of the incident-side polarizing plate 35, the liquid crystal panel 36, and the exit-side polarizing plate 37. Therefore, it is possible to suppress uneven color variations in the projected image light.

[0052] [Effects of the first embodiment] The projector 1 according to the present embodiment described above has the following advantages. The projector 1 includes a light source device 31, an image forming device 33, a projection optical device 40, a first fan 51, and a first rectifying section 433. The image forming device 33 has an incident-side polarizing plate 35, a liquid crystal panel 36, and a first flow path F1. The incident-side polarizing plate 35 is provided on the light incident side of the liquid crystal panel 36. The first flow path F1 is provided between the incident-side polarizing plate 35 and the liquid crystal panel 36. The light source device 31 emits light that is incident on the image forming device 33 . The projection optical device 40 projects the image light emitted from the image forming device 33 . The first fan 51 causes an airflow to flow through the first flow path F1. The first rectification section 433 is provided upstream of the airflow relative to the liquid crystal panel 36. The first rectification section 433 rectifies the airflow flowing through the first flow path F1 toward the incident-side polarizing plate 35.

[0053] According to this configuration, an air current can be circulated between the incident-side polarizing plate 35 and the liquid crystal panel 36, so that the incident-side polarizing plate 35 and the liquid crystal panel 36 can be cooled. At this time, the first rectification section 433 causes the airflow flowing through the first flow path F1 to flow toward the incident-side polarizing plate 35, thereby making it easier for the airflow that collides with the incident-side polarizing plate 35 to flow toward the center of the liquid crystal panel 36. This makes it easier to cool the central portion of the liquid crystal panel 36, which tends to be hot. Furthermore, the amount of relatively low-temperature airflow flowing through the portion of the liquid crystal panel 36 corresponding to the upstream side of the first flow path F1 can be reduced, while the temperature of the airflow flowing from the center of the liquid crystal panel 36 to the portion corresponding to the downstream side of the first flow path F1 can be lowered. In other words, compared to a case where the first rectifying section 433 is absent and the cooling efficiency is high for the portion of the liquid crystal panel 36 corresponding to the upstream side of the airflow and low for the portion of the liquid crystal panel 36 corresponding to the downstream side of the airflow, the cooling efficiency of the portion of the liquid crystal panel 36 corresponding to the upstream side of the airflow can be reduced and the cooling efficiency of the portion of the liquid crystal panel 36 corresponding to the downstream side of the airflow can be increased. This reduces the temperature difference between the portion of the liquid crystal panel 36 corresponding to the upstream side and the downstream side of the airflow. This reduces the occurrence of uneven cooling and temperature in the liquid crystal panel 36, and prevents color unevenness in the projected image light.

[0054] The projector 1 includes a second rectification section 434 as an incident side rectification section. The image forming device 33 has an incident side lens 34 and a second flow path F2. The incident-side lens 34 is provided on the light incident side relative to the incident-side polarizing plate 35 . The second flow path F2 corresponds to the incident-side flow path. The second flow path F2 is provided between the incident-side lens 34 and the incident-side polarizing plate 35. The second rectifying section 434 is provided upstream of the airflow relative to the incident-side polarizing plate 35, and rectifies the airflow flowing through the second flow path F2 toward the incident-side lens 34.

[0055] With this configuration, an air current can be passed between the entrance-side lens 34 and the entrance-side polarizing plate 35, so that the entrance-side lens 34 and the entrance-side polarizing plate 35 can be cooled. At this time, the second rectifying section 434 causes the airflow flowing through the second flow path F2 to flow toward the incident-side lens 34, making it easier for the airflow that collides with the incident-side lens 34 to flow toward the center of the incident-side polarizing plate 35. This makes it easier to cool the central portion of the incident-side polarizing plate, which is likely to be hot. Additionally, similar to the case where airflow flows through the first flow path F1 described above, compared to a case where the second rectification section 434 is not provided and the cooling efficiency of the portion of the incident-side polarizing plate 35 corresponding to the upstream side of the airflow is high and the cooling efficiency of the portion of the incident-side polarizing plate 35 corresponding to the downstream side of the airflow is low, the cooling efficiency of the portion of the incident-side polarizing plate 35 corresponding to the upstream side of the airflow can be reduced and the cooling efficiency of the portion of the incident-side polarizing plate 35 corresponding to the downstream side of the airflow can be increased. This reduces the temperature difference between the portion of the incident-side polarizing plate 35 corresponding to the upstream side and the portion of the incident-side polarizing plate 35 corresponding to the downstream side of the airflow. This makes it possible to suppress the occurrence of uneven cooling and temperature in the incident-side polarizing plate 35, and to suppress the occurrence of color unevenness in the projected image light.

[0056] The projector 1 includes a third rectification section 435 as an output side rectification section. The image forming apparatus includes an exit-side polarizing plate 37, an exit-side lens 38, and a third flow path F3. The exit-side polarizing plate 37 is provided on the light exit side of the liquid crystal panel 36 . The exit-side lens 38 is provided on the light exit side relative to the exit-side polarizing plate 37 . The third flow path F3 corresponds to an output-side flow path. The third flow path F3 is disposed between the output-side polarizing plate 37 and the output-side lens . The third rectifying section 435 is provided upstream of the airflow relative to the exit-side lens 38, and rectifies the airflow flowing through the third flow path F3 toward the exit-side polarizing plate 37.

[0057] According to this configuration, an air current can be circulated between the exit-side polarizing plate 37 and the exit-side lens 38, so that the exit-side polarizing plate 37 and the exit-side lens 38 can be cooled. At this time, the airflow flows toward the exit-side polarizing plate 37, which makes it easier for the airflow to come into contact with the exit-side polarizing plate 37 and also makes it easier for the airflow to flow through the central portion of the exit-side polarizing plate 37, where the temperature tends to be high. This reduces the temperature difference between the portion of the exit-side polarizing plate 37 that corresponds to the upstream side of the airflow and the portion that corresponds to the downstream side. This makes it possible to suppress the occurrence of uneven cooling and temperature in the exit-side polarizing plate 37 and to suppress the occurrence of color unevenness in the projected image light.

[0058] In the projector 1, the first rectification section 433 protrudes toward the first flow path F1, and the third rectification section 435 protrudes toward the third flow path F3. Note that the second rectification section 434 also protrudes toward the second flow path F2. The protruding dimension of the third rectifier 435 into the third flow path F3 is larger than the protruding dimension of the first rectifier 433 into the first flow path F1 and larger than the protruding dimension of the second rectifier 434 into the second flow path F2.

[0059] This configuration reduces the amount of airflow that contacts the upstream portion of the exit-side polarizing plate 37, and increases the amount of airflow that contacts the downstream portion of the exit-side polarizing plate 37. This effectively prevents uneven cooling and temperature in the exit-side polarizing plate 37, and effectively prevents color unevenness in the projected image light.

[0060] The projector 1 includes an exterior housing 2 that configures the exterior and houses a light source device 31, an image forming device 33, and a projection optical device 40. The first fan 51 draws in outside air from the exterior housing 2, and the airflow that has been rectified by the first rectifying section 433 and circulated through the first flow path F1 is discharged to the outside of the exterior housing 2.

[0061] With this configuration, the airflow flowing through the first flow path F1 is an airflow drawn in from outside the exterior housing 2, and so the temperature of the airflow flowing through the first flow path F1 can be lowered by the first fan 51. This effectively lowers the temperature of the entire liquid crystal panel 36. Therefore, for example, in a projector in which a large amount of light is incident on the liquid crystal panel 36 and the brightness of the projected image light is high, the occurrence of the above-mentioned cooling unevenness and color unevenness can be effectively suppressed.

[0062] In the projector 1, the first fan 51 is disposed so that the airflow direction D1 from the airflow outlet 513 of the first fan 51 intersects with an extension plane EP of the light incident surface 361 of the liquid crystal panel 36. The airflow sent out from the airflow outlet 513 of the first fan 51 is rectified by the first rectification section 433. More specifically, the airflow sent out from the airflow outlet 513 of the first fan 51 is rectified by the rectification sections 433 to 435.

[0063] With this configuration, the dimensions of the projector 1 in the direction in which the airflow flows through the first flow path F1 can be made smaller than when the airflow direction D1 does not intersect with the extension plane EP. This allows the projector 1 to be made more compact. On the other hand, even if a large fan with a large airflow rate is used as the first fan 51, the size of the projector 1 can be prevented from increasing. In this case, in a projector 1 in which the brightness of the projected image light is high, the liquid crystal panel 36, which is prone to becoming hot, can be effectively cooled.

[0064] [Modification of the first embodiment] FIG. 8 is a schematic diagram showing a modification of the image projection device 3A. In the projector 1 described above, the third rectification section 435 directs the airflow toward the output-side polarizing plate 37, which is located upstream in the optical path, of the output-side polarizing plate 37 and the output-side lens 38 that sandwich the third flow path F3. However, for example, as shown in FIG. 8 , the third rectification section 435 may direct the airflow toward the output-side lens 38.

[0065] According to this configuration, the third rectification section 435 as an output-side rectification section causes the airflow flowing through the third flow path F3, which is an output-side flow path, to flow toward the output-side lens 38, thereby making it easier for the airflow that collides with the output-side lens 38 to flow to the center of the output-side polarizing plate 37. This makes it easier to cool the central portion of the output-side polarizing plate 37, which tends to be hot. Furthermore, compared to a case where the third rectification section 435 is not provided and the cooling efficiency of the portion of the exit-side polarizing plate 37 corresponding to the upstream side of the third flow path F3 is high and the cooling efficiency of the portion of the exit-side polarizing plate 37 corresponding to the downstream side of the third flow path is low, the cooling efficiency of the portion of the exit-side polarizing plate 37 corresponding to the upstream side of the third flow path F3 can be reduced and the cooling efficiency of the portion of the exit-side polarizing plate 37 corresponding to the downstream side of the third flow path F3 can be increased. This reduces the temperature difference between the upstream side and downstream side of the exit-side polarizing plate 37. This makes it possible to suppress the occurrence of cooling unevenness and temperature unevenness in the exit-side polarizing plate 37, and to suppress the occurrence of color unevenness in the projected image light.

[0066] [Second embodiment] Next, a second embodiment of the present disclosure will be described. The projector according to this embodiment has a configuration similar to that of the projector 1 according to the first embodiment, but differs in that a circulation flow path is provided in the optical component housing 41B that houses the image forming device 33. In the following explanation, parts that are the same or approximately the same as parts that have already been explained will be assigned the same reference numerals and explanations thereof will be omitted.

[0067] [Outline of the projector and image projection device] FIG. 9 is a schematic diagram showing a part of each of the image projection device 3B and the cooling device 5 provided in the projector according to this embodiment. The projector according to this embodiment has the same configuration and functions as the projector 1 according to the first embodiment, except that it has an image projection device 3B, a part of which is shown in FIG. 9, instead of the image projection device 3A. The image projection device 3B according to this embodiment has the same configuration and functions as the image projection device 3A according to the first embodiment, except that it has an optical component housing 41B instead of the optical component housing 41A.

[0068] [Configuration of optical component housing] The optical component casing 41B has the same configuration and function as the optical component casing 41A, except that it has a sealed accommodating section 47 instead of the second accommodating section 43, the first duct section 45, and the second duct section 46. The sealed container 47 houses the image forming device 33 and the first fan 51, and defines a circulation flow path therein. The sealed container 47 has a first rectification section 433 provided upstream of the airflow relative to the liquid crystal panel 36, a second rectification section 434 provided upstream of the airflow relative to the incident-side polarizing plate 35, and a third rectification section 435 provided upstream of the airflow relative to the output-side lens 38. In addition, the sealed container 47 has a first communication path S1 and a second communication path S2 formed by the inner surface of the sealed container 47. That is, the projector according to this embodiment has the first communication path S1 and the second communication path S2. Inside the sealed container 47, the first fan 51 is arranged relative to the image forming device 33 in the same manner as the first fan 51 in the projector 1 according to the first embodiment. That is, inside the sealed container 47, the first fan 51 is arranged so that the airflow sent out from the sending section 513 flows in the +Y direction as it heads in the -Z direction.

[0069] The first communication path S1 connects the delivery section 513 of the first fan 51 with the upstream portion of the first flow path F1, the upstream portion of the second flow path F2, and the upstream portion of the third flow path F3. The upstream portion of the first flow path F1 is the upstream end of the airflow in the first flow path F1, specifically, the end on the delivery section 513 side between the incident-side polarizing plate 35 and the liquid crystal panel 36. Similarly, the upstream portion of the second flow path F2 is the upstream end of the airflow in the second flow path F2, specifically, the end on the delivery section 513 side between the incident-side lens 34 and the incident-side polarizing plate 35. The upstream portion of the third flow path F3 is the upstream end of the airflow in the third flow path F3, specifically, the end on the delivery section 513 side between the exit-side polarizing plate 37 and the exit-side lens 38. The rectifying sections 433 to 435 are arranged along the first communication path S1.

[0070] The second communication path S2 connects the downstream portions of the first flow path F1, the second flow path F2, and the third flow path F3 with the intake portions 511 and 512 of the first fan 51. The downstream portion of the first flow path F1 is the downstream end of the airflow in the first flow path F1, specifically, the end opposite the outlet portion 513 between the incident-side polarizing plate 35 and the liquid crystal panel 36. Similarly, the downstream portion of the second flow path F2 is the downstream end of the airflow in the second flow path F2, specifically, the end opposite the outlet portion 513 between the incident-side lens 34 and the incident-side polarizing plate 35. The downstream portion of the third flow path F3 is the downstream end of the airflow in the third flow path F3, specifically, the end opposite the outlet portion 513 between the output-side polarizing plate 37 and the output-side lens 38. The first communication passage S1 and the second communication passage S2 are flow paths within the sealed container portion 47 that are different from the flow paths F1 to F3.

[0071] The sealed container 47 has a communication path forming member 471 that forms the communication paths S1 and S2. The communication path forming member 471 has a heat receiving portion 472, a heat radiating portion 473, and partition walls 474 and 475. The heat receiving portion 472 is provided on the inner surface of the communication passage forming member 471. The heat receiving portion 472 receives heat from the airflow flowing along the heat receiving portion 472. In the present embodiment, the heat receiving portion 472 forms the first communication passage S1 and the second communication passage S2, and receives heat from the airflow flowing through the first communication passage S1 and the second communication passage S2. Heat dissipation section 473 is provided on a surface of communication path forming member 471 that is different from heat receiving section 472. In this embodiment, heat dissipation section 473 is provided on a surface of communication path forming member 471 that is opposite to heat receiving section 472. Heat dissipation section 473 dissipates heat received by heat receiving section 472. As a result, heat transferred from image forming device 33 is dissipated to the outside of sealed accommodating section 47, and ultimately to the outside of optical component casing 41B.

[0072] The partition walls 474 and 475 separate the sealed housing portion 47 into a space where the air-sending portion 513 of the first fan 51 is located and a space where the air-suction portions 511 and 512 are located. The partition wall 474 connects the inner surface of the sealed container portion 47 and the portion of the face of the first fan 51 on which the intake portion 511 is provided, on the side of the air delivery portion 513. The partition wall 475 connects the end of the entrance-side lens 34 on the first fan 51 side to the part of the surface of the first fan 51 on which the intake section 512 is provided on the side of the air-sending section 513. Therefore, the first communication passage S1 is a flow path provided in a portion of the sealed accommodating portion 47 in the direction in which the airflow caused by the first fan 51 is blown out relative to the partition walls 474, 475. The second communication passage S2 is a flow path from the downstream portion of each of the flow paths F1 to F3 to a portion on the opposite side of the partition walls 474, 475 from the direction in which the airflow caused by the first fan 51 is blown out.

[0073] [Airflow in a sealed enclosure] The first fan 51 circulates the airflow in a circulation flow path that includes the first communication path S1, the first flow path F1, the second flow path F2, the third flow path F3, and the second communication path S2. Specifically, when the first fan 51 sends out an airflow from the sending-out portion 513, the sent-out airflow flows through the first communication path S1 and flows into each of the flow paths F1 to F3. At this time, the airflow flowing into each of the flow paths F1 to F3 is rectified by each of the rectifying portions 433 to 435. The airflow flowing through the first communication path S1 receives heat from the heat receiving portion 472 and is cooled. The airflow that has flowed through each of the flow paths F1 to F3 in the -Z direction flows through the second communication path S2 to the intake sections 511, 512 of the first fan 51. At this time, the airflow flowing through the second communication path S2 receives heat from the heat receiving section 472 and is cooled. The airflow that has flowed through the second communication path S2 is sucked into the inside of the first fan 51 by the intake parts 511, 512, and is again sent out from the sending part 513. The heat received by the heat receiving part 472 is radiated to the outside of the optical component casing 41B by the heat radiating part 473. In this way, air flows stably within sealed container 47 partitioned by partitions 474 and 475, and incident-side polarizer 35, liquid crystal panel 36, and exit-side polarizer 37 that constitute image forming device 33 are cooled.

[0074] [Effects of the second embodiment] The projector according to this embodiment described above has the same effects as the projector 1 according to the first embodiment, and also has the following effects. The projector according to this embodiment includes a first communication path S1 and a second communication path S2. The first communication passage S1 connects the delivery section 513 of the first fan 51 with the upstream portions of the first flow path F1, the second flow path F2, and the third flow path F3. The second flow path F2 corresponds to an incident-side flow path, and the third flow path F3 corresponds to an exit-side flow path. The second communication passage S2 connects the downstream portions of the first flow path F1, the second flow path F2, and the third flow path F3 with the intake portions 511, 512 of the first fan 51. The first fan 51 circulates the airflow in a circulation flow path that includes the first communication path S1, the flow paths F1 to F3, and the second communication path S2.

[0075] With this configuration, the airflow that cools the incident-side polarizer 35, the liquid crystal panel 36, and the exit-side polarizer 37 can be circulated inside the projector. Therefore, there is no need to take in the gas that cools the incident-side polarizer 35, the liquid crystal panel 36, and the exit-side polarizer 37 from outside the projector. Therefore, the external appearance of the projector can be improved and dust can be prevented from entering the interior of the projector. Furthermore, the airflow sent out from the first fan 51 is divided into the first flow path F1, the second flow path F2, and the third flow path F3 and circulates therethrough, respectively. This prevents the cooling efficiency of one of the incident-side polarizing plate 35, the liquid crystal panel 36, and the exit-side polarizing plate 37 from being significantly lower than the cooling efficiency of the other members.

[0076] The projector according to this embodiment includes a communication path forming member 471 having a heat receiving portion 472 and a heat dissipating portion 473 . The heat receiving portion 472 forms at least one of the first communication passage S1 and the second communication passage S2, and receives heat from the airflow flowing through that one communication passage. In this embodiment, the heat receiving portion 472 forms the first communication passage S1 and the second communication passage S2, and receives heat from the airflow flowing through each of the communication passages S1, S2. The heat radiating portion 473 radiates the heat received by the heat receiving portion 472 to the outside of the circulation flow path. That is, the heat radiating portion 473 radiates the heat received by the heat receiving portion 472 to the outside of the communicating path forming member 471. This configuration can lower the temperature of the airflow flowing through the first communication path S1 and the second communication path S2, thereby effectively cooling the incident-side polarizing plate 35, the liquid crystal panel 36, and the exit-side polarizing plate 37, and thereby effectively suppressing the occurrence of the above-mentioned uneven cooling and color unevenness.

[0077] In the present embodiment, the heat receiving portion 472 forms the first communication passage S1 and the second communication passage S2 and receives heat from the airflow flowing through each of the communication passages S1, S2. However, this is not limiting, and the heat receiving portion 472 may form only one of the first communication passage S1 and the second communication passage S2 and receive heat from the airflow flowing through that one communication passage. Furthermore, the positions of the heat receiving portion 472 and the heat dissipation portion 473 in the communication passage forming member 471 can be changed as appropriate.

[0078] [Third embodiment] The third embodiment of the present disclosure will be described below. The projector according to this embodiment has a similar configuration to the projector 1 according to the first embodiment, but differs in that circulation flow paths for the airflow that flows through each of the flow paths F1 to F3 are provided inside the exterior housing 2. In the following explanation, parts that are the same or approximately the same as parts that have already been explained will be given the same reference numerals and explanations thereof will be omitted.

[0079] [Outline of the projector and image projection device] Fig. 10 is a schematic diagram showing an image projection device 3C and a cooling device 5 provided in a projector according to this embodiment. Note that Fig. 10 does not show the heat dissipation member 313 of the light source device 31 and the second fan 52 of the cooling device 5. The projector of this embodiment has the same configuration and functions as the projector 1 of the first embodiment, except that it has an image projection device 3C shown in Figure 10 instead of the image projection device 3A, and an airflow circulation flow path including flow paths F1 to F3 is provided inside the exterior housing 2. The image projection device 3C according to this embodiment has the same configuration and functions as the image projection device 3A according to the first embodiment, except that it has an optical component housing 41C instead of the optical component housing 41A.

[0080] [Configuration of optical component housing] The optical components casing 41C has the same configuration and functions as the optical components casing 41A according to the first embodiment, except that it has a sealed housing portion 48 instead of the first duct portion 45 and the second duct portion 46. That is, the optical components casing 41C has a first housing portion 42, a second housing portion 43, a third housing portion 44, and the sealed housing portion 48. The opening 431 of the second storage section 43 is an opening that discharges the airflow that has flowed through the first flow path F1 and the second flow path F2 in the +Z direction to a communicating passage forming member 481 described later in the sealed storage section 48, and allows the airflow that has flowed through the communicating passage forming member 481 to flow into the third flow path F3. In addition, the opening 432 of the second storage section 43 is an opening that discharges the airflow that has flowed through the third flow path F3 in the -Z direction to the connecting path forming member 482 described later of the sealed storage section 48, and allows the airflow sent out from the first fan 51 to flow into the first flow path F1 and the second flow path F2.

[0081] [Configuration of sealed storage unit] The sealed housing 48 is connected to the second housing 43 and houses therein the first fan 51. In this embodiment, the first fan 51 is disposed so that the intake portion 511 faces the -Y direction and the -Z direction, and the delivery portion 513 faces the +Y direction and the -Z direction. The sealed container has communication passage forming members 481 and 482 that form a flow passage within the sealed container .

[0082] The communication path forming member 481 constitutes a first communication path T1. The first communication path T1 connects an end of the first flow path F1 and an end of the second flow path F2 with an end of the third flow path F3. More specifically, the first communication path T1 is a communication path that connects the end of the first flow path F1 and the end of the second flow path F2 with the start of the third flow path F3. In other words, the first communication path T1 is a communication path that connects the end of the first flow path F1 and the end of the second flow path F2 in the +Z direction with the end of the third flow path F3 in the +Z direction.

[0083] The communication path forming member 481 has a heat receiving portion 4811 and a heat radiating portion 4812 . The heat receiving portion 4811 is a recess recessed in the +Z direction and forms the first communication path T1. The heat receiving portion 4811 receives heat from the airflow flowing through the first communication path T1. Heat dissipation portion 4812 is provided on a surface of communicating path forming member 481 that is different from heat receiving portion 4811. In this embodiment, heat dissipation portion 4812 is provided on a surface of communicating path forming member 481 that is opposite to heat receiving portion 4811. Heat dissipation portion 4812 dissipates the heat of the airflow received by heat receiving portion 4811 to the outside of communicating path forming member 481, i.e., to the outside of optical component casing 41B.

[0084] The communication path forming member 482 is formed in a substantially L-shape when viewed from the +X direction. The communication path forming member 482 constitutes the second communication path T2 and the third communication path T3. The second communication passage T2 communicates the end of the third flow path F3 with the intake section 511 of the first fan 51. More specifically, the second communication passage T2 is a communication passage that communicates the terminal end of the third flow path F3 with the intake section 511 of the first fan 51. In other words, the second communication passage T2 is a communication passage that communicates the end of the third flow path F3 in the -Z direction with the intake section 511. The third communication passage T3 communicates the delivery section 513 of the first fan 51 with the respective ends of the first flow path F1 and the second flow path F2. More specifically, the third communication passage T3 is a communication passage that communicates the delivery section 513 with the respective starting ends of the first flow path F1 and the second flow path F2. In other words, the third communication passage T3 is a communication passage that communicates the delivery section 513 with the -Z direction ends of the first flow path F1 and the second flow path F2.

[0085] The communication path forming member 482 includes a heat receiving portion 4821 , a heat radiating portion 4822 , and a partition wall 4823 . Heat receiving portion 4821 is provided on the inner surface of communication path forming member 482 formed in a substantially L-shape, and forms second communication path T2. That is, heat receiving portion 4821 is provided on inner surface 482A facing the -Y direction and the +Z direction and inner surface 482B facing the +Y direction and the +Z direction in communication path forming member 482, and forms second communication path T2. Heat receiving portion 4821 receives heat from the airflow flowing through second communication path T2. Heat dissipation portion 4822 is provided on a surface of communicating path forming member 482 that is different from heat receiving portion 4821. In this embodiment, heat dissipation portion 4822 is provided on a surface of communicating path forming member 482 that is opposite to heat receiving portion 4821. Heat dissipation portion 4822 dissipates the heat of the airflow received by heat receiving portion 4821 to the outside of communicating path forming member 482, i.e., to the outside of optical component casing 41B.

[0086] The partition wall 4823 separates the space in which the air-sending portion 513 of the first fan 51 is located from the space in which the air-sending portion 511 is located within the sealed housing portion 48. The partition wall 4823 connects the portion of the surface of the first fan 51 on which the air-sending portion 513 is provided that faces the air-sending portion 511 with the portion of the liquid crystal panel 36 that faces the first fan 51, thereby separating the second communication path T2 from the third communication path T3. In this embodiment, the partition wall 4823 has an inclined portion that is inclined with respect to the direction in which the airflow from the air-sending portion 513 is sent out, and also functions as an air guide portion that guides the airflow sent out from the air-sending portion 513 to the flow paths F1 and F2. In this embodiment, the first fan 51 is a single-sided intake centrifugal fan having the intake section 511, and therefore the partition 4823 is arranged as described above. On the other hand, if the first fan 51 is a double-sided intake centrifugal fan having the intake sections 511 and 512, the partition 4823 only needs to further connect the portion of the face of the first fan 51 on which the delivery section 513 is provided, on the intake section 512 side, with the portion of the incident-side lens 34 on the first fan 51 side.

[0087] [Airflow through each channel] The airflow sent out from the delivery section 513 of the first fan 51 flows through the third communication passage T3 partitioned by the partition wall 4823, and flows in the +Z direction toward the first flow path F1 and the second flow path F2. At this time, the airflow flowing through the first flow path F1 is rectified by the first rectification section 433 provided on the upstream side of the airflow with respect to the first flow path F1, and flows toward the incident-side polarizing plate 35. In addition, the airflow flowing through the second flow path F2 is rectified by the second rectification section 434 located on the upstream side of the airflow with respect to the second flow path F2, and flows toward the incident-side lens 34.

[0088] The airflow that has flowed through the first flow path F1 and the second flow path F2 in the +Z direction flows through the first communication path T1. At this time, the airflow flowing through the first communication path T1 flows along the heat receiving portion 4811 of the communication path forming member 481, and is thereby cooled. The heat of the airflow received by the heat receiving portion 4811 is radiated from the heat radiating portion 4812. The airflow that has flowed through the first communication passage T1 flows into the third flow passage F3. At this time, the airflow flowing through the third flow passage F3 is rectified by the third rectification section 435, which is located upstream of the airflow with respect to the third flow passage F3, and flows toward the exit-side polarizing plate 37.

[0089] The airflow that has flowed through the third flow path F3 in the -Z direction flows through the second communication path T2. At this time, the airflow flowing through the second communication path T2 flows along the heat receiving portion 4821 of the communication path forming member 482, and is thereby cooled. The heat of the airflow received by the heat receiving portion 4821 is radiated from the heat radiating portion 4822. The airflow that has flowed through the second communication passage T2 is sucked into the intake section 511 of the first fan 51. The airflow that has been sucked into the first fan 51 is sent out again from the delivery section 513, and flows through the third communication passage T3 to each of the flow paths F1 and F2.

[0090] [Effects of the third embodiment] The projector according to this embodiment described above has the same effects as the projector 1 according to the first embodiment, and also has the following effects. The projector according to this embodiment includes a first communication path T1 and a second communication path T2. The first communication passage T1 connects the ends of the first flow passage F1 and the second flow passage F2 with one end of the third flow passage F3. The third flow passage F3 corresponds to an emission side flow passage. The second communication passage T2 communicates the other end of the third flow path F3 with one of the intake section 511 and the delivery section 513 of the first fan 51. In the present embodiment, the second communication passage T2 communicates the other end of the third flow path F3 with the intake section 511 of the first fan 51. The first fan 51 circulates the airflow in a circulation flow path that includes the first flow path F1, the second flow path F2, the first communication path T1, the third flow path F3, and the second communication path T2.

[0091] With this configuration, the airflow that cools the incident-side polarizer 35, the liquid crystal panel 36, and the exit-side polarizer 37 can be circulated inside the projector. Therefore, there is no need to take in gas that cools the incident-side polarizer 35, the liquid crystal panel 36, and the exit-side polarizer 37 from outside the projector. Therefore, the external appearance of the projector can be improved and dust can be prevented from entering the interior of the projector. Furthermore, since the terminal end of the third flow path F3 and the intake section 511 of the first fan 51 are connected by the second communication path T2, the liquid crystal panel 36 is located upstream of the airflow relative to the exit-side polarizing plate 37. This allows the airflow before flowing to the exit-side polarizing plate 37 to flow through the liquid crystal panel 36, thereby improving the cooling effect of the liquid crystal panel 36.

[0092] In the third embodiment, the airflow delivered from the first fan 51 flows through the first flow path F1, the second flow path F2, the first communication path T1, the third flow path F3, and the second communication path T2, in this order. However, this is not limiting, and the airflow delivered from the first fan 51 may flow in the opposite direction to the flow direction in the third embodiment. In this case, the first fan 51 may be disposed so that the intake section 511 and the delivery section 513 are positioned opposite to each other. That is, in this case, the airflow delivered from the first fan 51 may flow through the second communication path T2, the third flow path F3, the first communication path T1, the first flow path F1, and the second flow path F2, in this order. With this configuration, the exit-side polarizing plate 37 is located upstream of the airflow relative to the liquid crystal panel 36. Therefore, the airflow before flowing to the liquid crystal panel 36 can be made to flow to the exit-side polarizing plate 37, thereby improving the cooling effect of the exit-side polarizing plate 37.

[0093] [Modification of the embodiment] The present disclosure is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present disclosure are included in the present disclosure. In each of the above embodiments, the projector includes the first flow path F1 provided between the incident-side polarizing plate 35 and the liquid crystal panel 36, as well as the second flow path F2 provided between the incident-side lens 34 and the incident-side polarizing plate 35, and the third flow path F3 provided between the exit-side polarizing plate 37 and the exit-side lens 38. However, this is not limiting, and at least one of the second flow path F2 and the third flow path F3 may be omitted. On the other hand, even when the projector includes at least one of the second flow path F2 and the third flow path F3, a rectifying unit that rectifies the airflow flowing through that at least one flow path may be omitted.

[0094] In each of the above embodiments, the protrusion dimension of the third flow rectifier 435 as the exit-side flow rectifier into the third flow path F3 is larger than the protrusion dimension of the first flow rectifier 433 into the first flow path F1. However, this is not limiting, and the protrusion dimension of the third flow rectifier 435 into the third flow path F3 may be the same as the protrusion dimension of the first flow rectifier 433 into the first flow path F1, or may be smaller than the protrusion dimension of the first flow rectifier 433 into the first flow path F1. Furthermore, the flow path width of the third flow path F3 is larger than the flow path width of the first flow path F1 and larger than the flow path width of the second flow path F2. However, this is not limiting, and the flow path width of the third flow path F3 may be the same as the flow path width of each of the flow paths F1, F2, or may be smaller than the flow path width of each of the flow paths F1, F2. In other words, the flow path widths of each of the flow paths F1 to F3 can be changed as appropriate.

[0095] In the first embodiment, the first fan 51 introduces outside air from the exterior housing 2 through the inlet 212. However, this is not limiting, and the first fan 51 may also suck in gas that has been introduced into the projector by another fan and circulated to another object to be cooled.

[0096] In the first and second embodiments, the first fan 51 is disposed so that the airflow direction D1 from the airflow outlet 513 of the first fan 51 intersects with the extension plane EP of the light incident surface 361 of the liquid crystal panel 36. However, this is not limiting, and the first fan 51 may be disposed so that the airflow direction D1 from the airflow outlet 513 is parallel to the extension plane EP when viewed from the +X direction.

[0097] In each of the above embodiments, the projector is provided with a transmissive liquid crystal panel 36 in which the light incident surface 361 and the light exit surface 362 are different. However, the present invention is not limited to this, and the projector may be provided with a reflective liquid crystal panel in which the light incident surface and the light exit surface are the same.

[0098] Summary of this disclosure A summary of this disclosure is provided below. [Appendix 1] an image forming device that forms image light, the image forming device having a liquid crystal panel, an incident-side polarizing plate provided on a light incident side of the liquid crystal panel, and a first flow path provided between the liquid crystal panel and the incident-side polarizing plate; a light source device that emits light to be incident on the image forming device; a projection optical device that projects the image light emitted from the image forming device; a first fan that causes an airflow to flow through the first flow path; a first rectification unit that is provided upstream of the airflow relative to the liquid crystal panel and rectifies the airflow flowing through the first flow path toward the incident-side polarizing plate, A projector characterized by:

[0099] According to this configuration, an air current can be circulated between the incident-side polarizing plate and the liquid crystal panel, thereby cooling the incident-side polarizing plate and the liquid crystal panel. At this time, the first rectifying section causes the airflow flowing through the first flow path to flow toward the incident-side polarizing plate, which makes it easier for the airflow that hits the incident-side polarizing plate to flow toward the center of the liquid crystal panel, making it easier to cool the center part of the liquid crystal panel, which tends to be hotter. Furthermore, the amount of relatively low-temperature airflow flowing through the portion of the liquid crystal panel corresponding to the upstream side of the first flow path can be reduced, while the temperature of the airflow flowing from the center of the liquid crystal panel to the portion corresponding to the downstream side of the first flow path can be lowered. In other words, compared to a case where the first rectification section is absent and the cooling efficiency is high for the portion of the liquid crystal panel corresponding to the upstream side of the airflow and low for the portion of the liquid crystal panel corresponding to the downstream side of the airflow, the cooling efficiency of the portion of the liquid crystal panel corresponding to the upstream side of the airflow can be reduced and the cooling efficiency of the portion of the liquid crystal panel corresponding to the downstream side of the airflow can be increased. This reduces the temperature difference between the portion of the liquid crystal panel corresponding to the upstream side and the downstream side of the airflow. Therefore, the occurrence of uneven cooling and temperature in the liquid crystal panel can be suppressed, and the occurrence of color unevenness in the projected image light can be suppressed.

[0100] [Appendix 2] 2. The projector according to claim 1, An incident side rectifier is provided, the image forming apparatus, an incident-side lens provided on the light incident side of the incident-side polarizing plate; an incident-side flow path provided between the incident-side polarizing plate and the incident-side lens, the incident-side rectifying unit is provided on the upstream side of the airflow relative to the incident-side polarizing plate, and rectifies the airflow flowing through the incident-side flow path toward the incident-side lens. A projector characterized by:

[0101] According to this configuration, an air current can be circulated between the incident-side lens and the incident-side polarizing plate, thereby cooling the incident-side lens and the incident-side polarizing plate. At this time, the incident-side rectifier directs the airflow flowing through the incident-side flow path toward the incident-side lens, making it easier for the airflow that hits the incident-side lens to flow toward the center of the incident-side polarizing plate, which makes it easier to cool the center part of the incident-side polarizing plate, where the temperature is high and easy to cool. Furthermore, similar to the case where airflow flows through the first flow path provided between the liquid crystal panel and the incident-side polarizing plate described above, compared to a case where the incident-side straightening section is absent and the cooling efficiency of the portion of the incident-side polarizing plate corresponding to the upstream side of the incident-side flow path is high and the cooling efficiency of the portion of the incident-side polarizing plate corresponding to the downstream side of the incident-side flow path is low, the cooling efficiency of the portion of the incident-side polarizing plate corresponding to the upstream side of the first flow path can be reduced and the cooling efficiency of the portion of the incident-side polarizing plate corresponding to the downstream side of the incident-side flow path can be increased. This reduces the temperature difference between the portion of the incident-side polarizing plate corresponding to the upstream side and the downstream side of the incident-side flow path. This reduces the occurrence of cooling and temperature unevenness in the incident-side polarizing plate and the occurrence of color unevenness in the projected image light.

[0102] [Appendix 3] In the projector according to Supplementary Note 1 or Supplementary Note 2, An output side rectifying unit is provided, the image forming apparatus, an exit-side polarizing plate provided on the light exit side of the liquid crystal panel; an exit-side lens provided on the light exit side of the exit-side polarizing plate; an output-side flow path disposed between the output-side polarizing plate and the output-side lens, the output-side rectifying unit is provided upstream of the airflow relative to the output-side lens, and rectifies the airflow flowing through the output-side flow path toward the output-side polarizing plate. A projector characterized by:

[0103] According to this configuration, an air current can be circulated between the exit-side polarizing plate and the exit-side lens, thereby cooling the exit-side polarizing plate and the exit-side lens. In this case, the airflow flows toward the exit-side polarizing plate, which not only makes it easier for the airflow to come into contact with the exit-side polarizing plate but also makes it easier for the airflow to flow to the central portion of the exit-side polarizing plate, where the temperature tends to be high. This reduces the temperature difference between the portion of the exit-side polarizing plate corresponding to the upstream side of the airflow and the portion corresponding to the downstream side. This therefore makes it possible to suppress uneven cooling and temperature in the exit-side polarizing plate and to suppress color unevenness in the projected image light.

[0104] [Appendix 4] In the projector according to Supplementary Note 1 or Supplementary Note 2, an output-side rectifying section provided on the light output side of the liquid crystal panel, the image forming apparatus, an exit-side polarizing plate provided on the light exit side of the liquid crystal panel; an exit-side lens provided on the light exit side of the exit-side polarizing plate; an output-side flow path disposed between the output-side polarizing plate and the output-side lens, the output-side rectifying unit is provided upstream of the airflow relative to the output-side polarizing plate, and rectifies the airflow flowing through the output-side flow path toward the output-side lens. A projector characterized by:

[0105] With this configuration, the exit-side rectifier directs the airflow flowing through the exit-side flow path toward the exit-side lens, making it easier for the airflow that collides with the exit-side lens to flow toward the center of the exit-side polarizing plate, thereby making it easier to cool the center portion of the exit-side polarizing plate, which tends to be hotter. In addition, similar to the case where an airflow flows through the exit-side flow path provided between the liquid crystal panel and the entrance-side polarizer described above, compared to a case where there is no exit-side straightening section and the cooling efficiency of the portion of the exit-side polarizer corresponding to the upstream side of the exit-side flow path is high and the cooling efficiency of the portion of the exit-side polarizer corresponding to the downstream side of the exit-side flow path is low, the cooling efficiency of the portion of the exit-side polarizer corresponding to the upstream side of the exit-side flow path can be reduced and the cooling efficiency of the portion of the exit-side polarizer corresponding to the downstream side of the exit-side flow path can be increased. This reduces the temperature difference between the portion of the exit-side polarizer corresponding to the upstream side and the portion of the exit-side polarizer corresponding to the downstream side of the exit-side flow path. Therefore, the occurrence of cooling unevenness and temperature unevenness in the exit-side polarizer can be suppressed, and the occurrence of color unevenness in the projected image light can be suppressed.

[0106] [Appendix 5] In the projector according to Supplementary Note 3 or Supplementary Note 4, the first flow straightening portion protrudes toward the first flow path, the exit-side flow straightening portion protrudes toward the exit-side flow path, a protruding dimension of the output-side rectifying portion into the output-side flow path is larger than a protruding dimension of the first rectifying portion into the first flow path; A projector characterized by:

[0107] This configuration reduces the flow rate of the airflow that contacts the upstream portion of the exit-side polarizing plate and increases the flow rate of the airflow that contacts the downstream portion of the exit-side flow path, thereby effectively suppressing uneven cooling and temperature in the exit-side polarizing plate and effectively suppressing color unevenness in the projected image light.

[0108] [Appendix 6] 6. The projector according to claim 1, an exterior housing that houses the image forming device, the light source device, and the projection optical device and forms an exterior; the first fan draws in outside air from the exterior housing; The airflow that has been rectified by the first rectification section and has flowed through the first flow path is discharged to the outside of the exterior housing. A projector characterized by:

[0109] With this configuration, the airflow flowing through the first flow path is airflow drawn in from outside the exterior housing, so the temperature of the airflow flowing through the first flow path can be lowered by the first fan. This effectively lowers the temperature of the entire liquid crystal panel. Therefore, for example, in a projector in which a large amount of light is incident on the liquid crystal panel and the brightness of the projected image light is high, the occurrence of the above-mentioned cooling unevenness and color unevenness can be effectively suppressed.

[0110] [Appendix 7] 6. The projector according to claim 3, a first communication passage that connects an end of the first flow passage and one end of the emission side flow passage; a second communication passage that communicates the other end of the outlet-side flow path with one of the intake section and the outlet section of the first fan, the first fan circulates the airflow through a circulation flow path that includes the first flow path, the first communication path, the emission side flow path, and the second communication path; A projector characterized by:

[0111] With this configuration, the airflow that cools the liquid crystal panel and the exit-side polarizer can be circulated within the projector. This eliminates the need to take in gas to cool the liquid crystal panel and the exit-side polarizer from outside the projector. This not only improves the appearance of the projector, but also prevents dust from entering the interior of the projector. When the other end of the exit-side flow path is connected to the intake section of the first fan via the second communication path, the liquid crystal panel is located upstream of the airflow relative to the exit-side polarizer, allowing the airflow to flow through the liquid crystal panel before passing through the exit-side polarizer, thereby improving the cooling effect of the liquid crystal panel. On the other hand, when the other end of the output-side flow path is connected to the outlet section of the first fan via the second communication path, the output-side polarizing plate is located upstream of the liquid crystal panel in the airflow, so that the airflow before flowing to the liquid crystal panel can be passed through the output-side polarizing plate, thereby improving the cooling effect of the output-side polarizing plate.

[0112] [Appendix 8] 6. The projector according to claim 3, a first communication passage that communicates a delivery portion of the first fan with an upstream portion of each of the first flow path and the outlet-side flow path; a second communication passage that communicates a downstream portion of each of the first flow path and the outlet-side flow path with an intake portion of the first fan, the first fan circulates the airflow through a circulation flow path that includes the first communication path, each of the first flow path and the emission-side flow path, and the second communication path; A projector characterized by:

[0113] With this configuration, similar to the above, the airflow that cools the liquid crystal panel, the entrance-side polarizer, and the exit-side polarizer can be circulated within the projector. Therefore, there is no need to take in the gas that cools the liquid crystal panel, the entrance-side polarizer, and the exit-side polarizer from outside the projector. This not only improves the appearance of the projector, but also prevents dust from entering the interior of the projector. Furthermore, the airflow sent out from the first fan is divided into the first flow path and the exit-side flow path, which prevents the cooling efficiency of one of the liquid crystal panel and the exit-side polarizing plate from being significantly lower than the cooling efficiency of the other.

[0114] [Appendix 9] 10. The projector according to claim 7, a communication passage forming member that forms at least one of the first communication passage and the second communication passage and has a heat receiving portion that receives heat from an airflow flowing through the one communication passage, and a heat dissipation portion that dissipates the heat received by the heat receiving portion to the outside of the circulation flow path, A projector characterized by:

[0115] This configuration can reduce the temperature of the airflow flowing through at least one of the communication paths, thereby effectively cooling the liquid crystal panel and the exit-side polarizer, and thereby effectively suppressing the occurrence of the above-mentioned uneven cooling and color unevenness.

[0116] [Appendix 10] 10. The projector according to claim 1, the first fan is disposed so that a blowing direction of an airflow from a blowing portion of the first fan intersects with an extension plane of a light incident surface of the liquid crystal panel; The airflow sent out from the delivery portion of the first fan is rectified by the first rectification portion. A projector characterized by:

[0117] With this configuration, the dimensions of the projector in the direction in which the airflow flows through the first flow path can be reduced compared to when the airflow direction from the airflow outlet does not intersect with the extension plane of the airflow outlet of the first fan. This allows for a more compact projector. Meanwhile, even if a large fan with a large airflow rate is used as the first fan, the size of the projector can be prevented from increasing. In this case, in a projector that projects image light with high brightness, the liquid crystal panel, which tends to become hot, can be effectively cooled. [Explanation of symbols]

[0118] 1...projector, 2...exterior housing, 212...inlet, 221...outlet, 3A, 3B, 3C...image projection device, 31...light source device, 311...light emitting section, 312...support substrate, 313...heat dissipation member, 32...reflector, 33...image forming device, 34...incident side lens, 35...incident side polarizing plate, 351...light incident surface, 352...light exit surface, 36...liquid crystal panel, 361...light incident surface, 362...light exit surface, 37...exit side polarizing plate, 372...light exit surface, 38...exit side lens, 39...optical path changing member, 40...projection optical device, 41A, 41B, 41C...optical component housing, 42...first storage section, 43...second storage section , 431, 432...opening, 433...first straightening section, 434...second straightening section, 435...third straightening section, 44...third accommodating section, 45...first duct section, 46...second duct section, 47, 48...sealed accommodating section, 471, 481, 482...communicating passage forming member, 472, 4811, 4821...heat receiving section, 473, 4812, 4822...heat dissipation section, 5...cooling device, 51...first fan, 511, 512...intake section, 513...discharge section, 52...second fan, D1...discharge direction, EP...extension surface, F1...first flow path, F2...second flow path, F3...third flow path, S1, T1...first communicating passage, S2, T2...second communicating passage, VL...imaginary line.

Claims

1. an image forming device that forms image light, the image forming device including a liquid crystal panel, an incident-side polarizing plate provided on a light incident side of the liquid crystal panel, and a first flow path provided between the liquid crystal panel and the incident-side polarizing plate; a light source device that emits light to be incident on the image forming device; a projection optical device that projects the image light emitted from the image forming device; a first fan that causes an airflow to flow through the first flow path; a first rectification unit that is provided upstream of the airflow relative to the liquid crystal panel and rectifies the airflow flowing through the first flow path toward the incident-side polarizing plate, A projector characterized by:

2. The projector according to claim 1 , An incident side rectifier is provided, the image forming apparatus, an incident-side lens provided on the light incident side of the incident-side polarizing plate; an incident-side flow path provided between the incident-side polarizing plate and the incident-side lens, the incident-side rectifying unit is provided on the upstream side of the airflow relative to the incident-side polarizing plate, and rectifies the airflow flowing through the incident-side flow path toward the incident-side lens. A projector characterized by:

3. The projector according to claim 1 , An output side rectifying unit is provided, the image forming apparatus, an exit-side polarizing plate provided on the light exit side of the liquid crystal panel; an exit-side lens provided on the light exit side of the exit-side polarizing plate; an output-side flow path disposed between the output-side polarizing plate and the output-side lens, the output-side rectifying unit is provided upstream of the airflow relative to the output-side lens, and rectifies the airflow flowing through the output-side flow path toward the output-side polarizing plate. A projector characterized by:

4. The projector according to claim 1 , an output-side rectifying section provided on the light output side of the liquid crystal panel, the image forming apparatus, an exit-side polarizing plate provided on the light exit side of the liquid crystal panel; an exit-side lens provided on the light exit side of the exit-side polarizing plate; an output-side flow path disposed between the output-side polarizing plate and the output-side lens, the output-side rectifying unit is provided upstream of the airflow relative to the output-side polarizing plate, and rectifies the airflow flowing through the output-side flow path toward the output-side lens. A projector characterized by:

5. 5. The projector according to claim 3, the first flow straightening portion protrudes toward the first flow path, the exit-side flow straightening portion protrudes toward the exit-side flow path, a protruding dimension of the output-side rectifying portion into the output-side flow path is larger than a protruding dimension of the first rectifying portion into the first flow path; A projector characterized by:

6. 5. The projector according to claim 1, an exterior housing that houses the image forming device, the light source device, and the projection optical device and forms an exterior; the first fan draws in outside air from the exterior housing; The airflow that has been rectified by the first rectification section and has flowed through the first flow path is discharged to the outside of the exterior housing. A projector characterized by:

7. 5. The projector according to claim 3, a first communication passage that connects an end of the first flow passage and one end of the emission side flow passage; a second communication passage that communicates the other end of the outlet-side flow path with one of the intake section and the outlet section of the first fan, the first fan circulates the airflow through a circulation flow path including the first flow path, the first communication path, the emission-side flow path, and the second communication path; A projector characterized by:

8. 5. The projector according to claim 3, a first communication passage that communicates a delivery portion of the first fan with an upstream portion of each of the first flow path and the outlet-side flow path; a second communication passage that communicates a downstream portion of each of the first flow path and the outlet-side flow path with an intake portion of the first fan, the first fan circulates the airflow through a circulation flow path that includes the first communication path, each of the first flow path and the emission-side flow path, and the second communication path; A projector characterized by:

9. The projector according to claim 7 , a communication passage forming member that forms at least one of the first communication passage and the second communication passage, and that has a heat receiving portion that receives heat from an airflow flowing through the one communication passage, and a heat dissipation portion that dissipates the heat received by the heat receiving portion to the outside of the circulation flow path, A projector characterized by:

10. The projector according to claim 8, a communication passage forming member that forms at least one of the first communication passage and the second communication passage, and that has a heat receiving portion that receives heat from an airflow flowing through the one communication passage, and a heat dissipation portion that dissipates the heat received by the heat receiving portion to the outside of the circulation flow path, A projector characterized by:

11. 5. The projector according to claim 1, the first fan is disposed so that a blowing direction of an airflow from a blowing portion of the first fan intersects with an extension plane of a light incident surface of the liquid crystal panel, The airflow sent out from the delivery portion of the first fan is rectified by the first rectification portion. A projector characterized by:

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