Projector

Abstract

Provided is a projector. The cooling efficiency of the heat source can be improved. The projector includes: a light source; a first lens that converges the white light from the light source; one image forming unit that emits image light obtained by modulating the white light from the first lens; a second lens that converges the image light; a projection lens that projects image light; an outer housing; a first holder having a first heat receiving surface therein, holding the first lens and an incident side end portion of the image forming unit, and sealing a first space including a space between a light exit surface of the first lens and a light incident surface of the image forming unit; and a second holder having a second heat receiving surface therein, holding an exit-side end portion of the image forming unit and the second lens, and sealing a second space including a space between a light exit surface of the image forming unit and a light incident surface of the second lens, at least one of the first space and the second space being filled with a cooling medium, the outer peripheral surface of the image forming unit is exposed inside the exterior case.

Description

Technical Field

[0001] The utility model relates to a projector. Background Art

[0002] Conventionally, there is known a projector including a light source, a light modulating device for modulating light emitted from the light source, and a projection lens for projecting the light modulated by the light modulating device (see, for example, Patent Document 1).

[0003] The projector described in Patent Document 1 is provided with a cooling device for cooling a light source and a light modulator. The cooling device includes a light source cooling unit provided on the light source, a holding frame for holding the light modulator, a heat exchanger arranged in a sealed frame for accommodating the light modulator, a radiator, and a pump for circulating a liquid refrigerant. In addition, the cooling device includes a plurality of fans arranged in the sealed frame, and a gas such as helium is sealed in the sealed frame.

[0004] The light source is cooled by the liquid coolant flowing through the light source cooling unit. The light modulator is cooled by gas that circulates in the sealed housing by a plurality of fans and is cooled by the heat sink in addition to the liquid coolant flowing through the holding frame.

[0005] In addition, a rear-projection projector having a simplified structure is known (see, for example, Patent Document 2).

[0006] In the rear projection type projector described in Patent Document 2, light emitted from a light source is incident on a liquid crystal panel via a first transmission Fresnel lens. Light modulated by the liquid crystal panel is projected by a projection lens onto a screen mounted on a housing via a second transmission Fresnel lens. The first transmission Fresnel lens, the liquid crystal panel, the second transmission Fresnel lens, and the projection lens are arranged in the housing.

[0007] Patent Document 1: Japanese Patent Application Publication No. 2020-79950

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 7-319066

[0009] In recent years, small projectors are also required to project images with higher brightness. However, in order to increase the brightness of the projected image, the intensity of the light source needs to be increased. In this case, the temperature of the light source is likely to increase, and the light source is likely to deteriorate. In addition, if a liquid crystal panel is used as a light modulation element, the amount of light incident on the liquid crystal panel increases, and the temperature of the liquid crystal panel increases, which may affect the operation of the liquid crystal.

[0010] In this regard, it is considered to combine the structure described in Patent Document 1 to increase the amount of light incident from the light source to the liquid crystal panel to achieve high brightness of the projected image, and adopt the cooling device described in Patent Document 1 to cool the light source and the liquid crystal panel by liquid refrigerant to suppress the degradation of the light source caused by temperature and make the liquid crystal panel work stably. However, if such a cooling device is adopted, even if the structure of the optical system is simplified as in the projector described in Patent Document 2, there is still a problem that the projector is easy to be large-scale.

[0011] Therefore, a structure capable of improving the cooling efficiency of the heat source is desired even for a small projector. Utility Model Content

[0012] A projector according to one embodiment of the present invention comprises: a light source emitting white light; a first lens condensing the white light emitted from the light source; an image forming unit emitting image light modulated from the white light incident from the first lens; a second lens condensing the image light emitted from the image forming unit; a projection lens projecting the image light incident from the second lens; an outer casing accommodating the light source, the first lens, the image forming unit, the second lens and the projection lens; a first holder having a first heat receiving surface inside, holding the first lens and the incident side end of the image forming unit, and providing a light emitting surface of the first lens and the incident side end of the image forming unit. The first space included between the light incident surfaces of the image forming unit is sealed; and a second holder, which has a second heating surface inside, holds the exit-side end of the image forming unit and the second lens, and seals the second space included between the light exit surface of the image forming unit and the light incident surface of the second lens, and at least one of the first space and the second space is filled with a cooling medium, the cooling medium absorbs heat from the image forming unit, convects inside the at least one space, and transfers heat to the heating surface of the first heating surface and the second heating surface exposed to the at least one space, and the outer peripheral surface of the image forming unit is exposed inside the outer casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram showing the structure of the projector in the first embodiment.

[0014] Figure 2 It is a schematic diagram showing the structure of a projector in the second embodiment.

[0015] Figure 3 It is a schematic diagram showing the structure of a projector in the third embodiment.

[0016] Figure 4It is a schematic diagram showing the structure of a projector in the fourth embodiment.

[0017] Figure 5 It is a schematic diagram showing the structure of a projector in the fifth embodiment.

[0018] Description of symbols

[0019] 1A, 1B, 1C, 1D, 1E projectors; 2A, 2C outer casings; 2A5 inlet; 2A6, 2C6 outlets; 3 image projection unit; 31 light source; 32 base member; 33 reflector; 34 first lens; 342 light exit surface; 35 light modulation element; 351 incident side polarizing plate; 3511 light incident surface; 3512 light exit surface; 352 image forming unit; 3521 light incident surface; 3522 light exit surface; 3523 peripheral surface; 353 liquid crystal panel; 3531 light incident surface; 3532 light exit surface; 354 ​​color filter; 355 exit side polarizing plate; 3551 light incident surface; 3552 light exit surface; 36 second lens; 361 light incident surface; 362 light exit surface; 37 optical path change Components; 371 light incident surface; 372 surface; 38 projection lens; 4A, 4B, 4D, 4E holder; 4A1, 4D1 first holder; 4A11, 4D11 first heating surface; 4A12, 4D12 first heat dissipation surface; 4A13, 4D13 first heat sink; 4A2, 4E2 second holder; 4A21, 4E21 second heating surface; 4A22, 4E22 second heat dissipation surface; 4A23, 4E23 second heat sink; 5 power supply; 6 heat conduction component; 61 heat transport component; 62 heat dissipation component; 7 cooling fan; 71 second cooling fan (second fan); 72 first cooling fan (first fan); 8 circulation fan; SA1, SD1 first space; SA2, SE2 second space; HS heat source. DETAILED DESCRIPTION

[0020] [First embodiment]

[0021] Hereinafter, a first embodiment of the present invention will be described based on the drawings.

[0022] [Schematic structure of the projector]

[0023] Figure 1 1 is a schematic diagram showing the structure of a projector 1A according to the present embodiment.

[0024] The projector 1A of this embodiment projects image light corresponding to image information. Figure 1 As shown, the projector 1A includes an outer casing 2A, an image projection unit 3, a holder 4A, a power source 5, a heat transfer member 6, and a cooling fan 7. Although not shown in the figure, the projector 1A includes a control unit that controls the operation of the projector 1A.

[0025] [Structure of the outer casing]

[0026] The outer casing 2A is a substantially rectangular parallelepiped casing constituting the outer shell of the projector 1A. The outer casing 2A is connected to the projection lens 38 of the image projection unit 3 and accommodates the image projection unit 3, the holder 4A, the power supply 5, the heat conduction member 6, and the cooling fan 7.

[0027] The outer casing 2A has a top surface and a bottom surface (not shown) in addition to a front surface 2A1 , a rear surface 2A2 , a left side surface 2A3 , and a right side surface 2A4 .

[0028] On the front surface 2A1 , a portion of the projection lens 38 constituting the image projection unit 3 is exposed.

[0029] The back surface 2A2 is a surface of the outer casing 2A that is opposite to the front surface 2A1.

[0030] The left side surface 2A3 is a surface intersecting with the front side 2A1 and the back side 2A2.

[0031] The right side surface 2A4 is a surface of the outer casing 2A that is opposite to the left side surface 2A3 .

[0032] The outer casing 2A further has an inlet 2A5 and an outlet 2A6.

[0033] The introduction port 2A5 is provided on the left side surface 2A3. The introduction port 2A5 introduces the gas outside the outer casing 2A into the inner part of the outer casing 2A as cooling gas.

[0034] The discharge port 2A6 is provided on the right side surface 2A4. That is, the discharge port 2A6 is provided on the side surface of the outer case 2A opposite to the side surface provided with the introduction port 2A5. The discharge port 2A6 discharges the cooling gas inside the outer case 2A to the outside of the outer case 2A.

[0035] The flow of cooling gas introduced into the exterior case 2A from the introduction port 2A5 and discharged to the outside of the exterior case 2A from the discharge port 2A6 is performed by driving the cooling fan 7 described later.

[0036] [Structure of image projection unit]

[0037] The image projection unit 3 is accommodated in the outer casing 2A and projects image light corresponding to the image signal. The image projection unit 3 includes a light source 31, a base member 32, a reflector 33, a first lens 34, a light modulator 35, a second lens 36, an optical path changing member 37, and a projection lens 38.

[0038] [Structure of light source and base member]

[0039] The light source 31 emits white light. Specifically, the light source 31 emits white light including p-polarized light and s-polarized light. The light source 31 is configured to include at least one light emitting element, and the light emitting element is composed of a solid light source such as an LED (Light Emitting Diode). The light source 31 is one of the heat sources HS of the projector 1A, and is arranged on the base member 32. The light source 31 is arranged at a position closer to the right side surface 2A4 than the projection lens 38, and emits white light in the direction from the right side surface 2A4 toward the left side surface 2A3. In addition, the reflector 33, the first lens 34, the light modulation element 35, the second lens 36 and the optical path changing member 37 are arranged on the optical path of the white light emitted from the light source 31.

[0040] The base member 32 is made of metal, for example, and supports the light source 31. The base member 32 is connected to a heat transfer member 6 described later, and the heat transferred from the light source 31 to the base member 32 is transferred to the heat transfer member 6.

[0041] [Structure of reflector and first lens]

[0042] The reflector 33 makes the traveling direction of the light emitted from the light source 31 consistent. The reflector 33 and the light source 31 are connected so that no light leakage occurs. The same applies to the reflector 33 and the first lens 34.

[0043] The reflector 33 may be a tetrahedral pyramid reflector, an ellipsoidal reflector having a rotational ellipsoidal surface, or a parabolic reflector having a rotational parabola. In addition, the reflector 33 may be a hollow reflector having a space formed therein, or a solid reflector filled with a light-transmitting material.

[0044] The first lens 34 converges the light emitted from the light source 31 and incident via the reflector 33. The first lens 34 is composed of a Fresnel lens, and effectively expands the incident light at a short distance. That is, the first lens 34 is a first Fresnel lens. The details will be described later, and the light exit surface 342 of the first lens 34 is exposed inside the first holder 4A1 described later. The first cooling medium filled in the first holder 4A1 can contact the light exit surface 342.

[0045] [Structure of light modulation element]

[0046] The light modulator 35 modulates the white light incident from the first lens 34 according to an image signal input from a control unit (not shown) to emit color image light. That is, the light modulator 35 modulates the white light emitted from the light source 31 according to the image signal to emit full-color image light. In this embodiment, the projector 1A includes one light modulator 35. In other words, the image projection unit 3 includes one light modulator 35.

[0047] The light modulation element 35 includes one incident-side polarizing plate 351 and one image forming unit 352 .

[0048] [Structure of incident-side polarizing plate]

[0049] The incident-side polarizing plate 351 is separated from the first lens 34 toward the light emitting side of the first lens 34 and is separated from the image forming unit 352 toward the light incident side of the image forming unit 352. Specifically, the incident-side polarizing plate 351 is separated from the liquid crystal panel 353 constituting the image forming unit 352 toward the light incident side of the liquid crystal panel 353.

[0050] The incident side polarizing plate 351 has a light incident surface 3511 opposite to the first lens 34 and a light exit surface 3512 on the opposite side of the light incident surface 3511. The light incident surface 3511 and the light exit surface 3512 are respectively exposed inside the first holder 4A1 described later. That is, the first cooling medium described later in the first holder 4A1 can contact the light incident surface 3511 and the light exit surface 3512 respectively.

[0051] The incident-side polarizing plate 351 transmits the first linearly polarized light and absorbs the second linearly polarized light among the light incident from the first lens 34. One of the first linearly polarized light and the second linearly polarized light is p-polarized light, and the other linearly polarized light is s-polarized light.

[0052] In this embodiment, in order to simplify the structure of the projector 1A, the light source 31 emits light including p-polarized light and s-polarized light. Therefore, the incident-side polarizing plate 351 that absorbs the second linearly polarized light generates heat due to the incidence of white light emitted from the light source 31. In this way, the incident-side polarizing plate 351 is one of the heat sources HS of the projector 1A.

[0053] [Structure of Image Forming Unit]

[0054] The image forming unit 352 forms image light corresponding to the image signal by modulating the light incident from the incident side polarizing plate 351 according to the image signal. The image forming unit 352 includes a liquid crystal panel 353, a color filter 354, and an exit side polarizing plate 355. In the present embodiment, the image forming unit 352 is configured as a unit in which the liquid crystal panel 353, the color filter 354, and the exit side polarizing plate 355 are integrated.

[0055] The image forming unit 352 has a light incident surface 3521 , a light exit surface 3522 , and an outer peripheral surface 3523 .

[0056] The light incident surface 3521 faces the incident-side polarizing plate 351 . White light is incident on the light incident surface 3521 from the incident-side polarizing plate 351 .

[0057] The light exit surface 3522 is a surface of the image forming unit 352 on the opposite side to the light incident surface 3521. The light exit surface 3522 emits image light formed by the image forming unit 352.

[0058] The peripheral surface 3523 is a surface intersecting the light incident surface 3521 and the light exit surface 3522, and is a surface along a circumferential direction centered on the incident direction of light with respect to the image forming unit 352. On the peripheral surface 3523, a portion constituted by the peripheral surface of the liquid crystal panel 353 is a portion where wiring extending from the liquid crystal panel 353 is exposed.

[0059] [Structure of LCD panel]

[0060] The liquid crystal panel 353 is a transmissive liquid crystal panel that forms the image light and emits the formed image light along the traveling direction of the light incident from the incident-side polarizing plate 351. The liquid crystal panel 353 has a light incident surface 3531 and a light emitting surface 3532.

[0061] The light incident surface 3531 is a surface that faces the incident-side polarizing plate 351 and on which light is incident from the incident-side polarizing plate 351. The light incident surface 3531 constitutes the light incident surface 3521.

[0062] The light emitting surface 3532 is a surface on the opposite side to the light incident surface 3531 , and emits light that has passed through the liquid crystal panel 353 .

[0063] The liquid crystal panel 353 generates heat due to incident light and power supply. In addition, the liquid crystal in the liquid crystal panel 353 deteriorates due to heat. Therefore, the liquid crystal panel 353 is one of the heat sources HS that need to be cooled in the projector 1A. That is, the image forming unit 352 is the heat source HS in the projector 1A.

[0064] [Structure of Color Filter]

[0065] The color filter 354 is arranged on the light emitting surface 3532. Although detailed illustration is omitted, the color filter 354 has a plurality of color filter elements arranged according to one pixel formed by the liquid crystal panel 353. The color filter element is composed of a red color filter, a green color filter, and a blue color filter, and the red color filter, the green color filter, and the blue color filter are arranged according to the sub-pixels of the corresponding pixels. In addition, the red color filter is a color filter that allows red light to pass through, the green color filter is a color filter that allows green light to pass through, and the blue color filter is a color filter that allows blue light to pass through.

[0066] However, the color filter 354 is not limited to such a color filter, and the color filter 354 may be a single-color color filter provided corresponding to each pixel.

[0067] [Structure of the polarizing plate on the output side]

[0068] The output-side polarizing plate 355 is fixed to the light output surface 3532 of the liquid crystal panel 353 through the color filter 354. That is, the light incident surface 3551 of the output-side polarizing plate 355 is fixed in contact with the light output surface of the color filter 354. In addition, the output-side polarizing plate 355 is arranged away from the second lens 36 toward the light incident side of the second lens 36.

[0069] The light exit surface 3552 of the exit-side polarizing plate 355 constitutes the light exit surface 3522 of the image forming unit 352. The light exit surface 3552 is exposed inside the second holder 4A2, and the second cooling medium in the second holder 4A2 can contact the light exit surface 3552, which will be described in detail later.

[0070] When the polarization transmission axis of the exit-side polarizing plate 355 and the polarization transmission axis of the incident-side polarizing plate 351 are orthogonal to each other, the exit-side polarizing plate 355 transmits the light modulated by the liquid crystal panel 353 and absorbs the light not modulated by the liquid crystal panel 353. When the polarization transmission axis of the exit-side polarizing plate 355 and the polarization transmission axis of the incident-side polarizing plate 351 are parallel to each other, the exit-side polarizing plate 355 absorbs the light modulated by the liquid crystal panel 353 and transmits the light not modulated by the liquid crystal panel 353. Therefore, the exit-side polarizing plate 355 is also one of the heat sources HS of the projector 1A.

[0071] Although the details are described later, the incident side end of the image forming unit 352 is held by the first holder 4A1 described later. Therefore, the light incident surface 3521 of the image forming unit 352 is exposed in the first holder 4A1, and the first cooling medium in the first holder 4A1 can contact the light incident surface 3521.

[0072] The light-emitting end of the image forming unit 352 is held by the second holder 4A2 described below. Therefore, the light-emitting surface 3522 of the image forming unit 352 is exposed in the second holder 4A2, and the second cooling medium in the second holder 4A2 can contact the light-emitting surface 3522.

[0073] On the other hand, the outer peripheral surface 3523 of the image forming unit is exposed inside the outer casing 2A. Therefore, the wiring extending from the liquid crystal panel 353 can be easily led out into the outer casing 2A without being engaged with the first holder 4A1 and the second holder 4A2.

[0074] [Structure of the second lens]

[0075] The second lens 36 is arranged to be separated from the exit-side polarizing plate 355 toward the light exit side of the exit-side polarizing plate 355. The second lens 36 converges the image light emitted from the exit-side polarizing plate 355 and makes it incident on the optical path changing member 37. The second lens 36 is composed of a Fresnel lens. That is, the second lens 36 is a second Fresnel lens. The light incident surface 361 of the light incident surface 361 and the light exit surface 362 of the second lens 36 is exposed inside the second holder 4A2, and the second cooling medium in the second holder 4A2 can contact the light incident surface 361.

[0076] [Structure of the optical path changing component]

[0077] The optical path changing member 37 is disposed on the optical path of the image light between the second lens 36 and the projection lens 38. That is, the optical path changing member 37 is composed of a reflecting mirror disposed between the light modulator 35 and the projection lens 38 on the optical path of the image light.

[0078] The optical path changing member 37 includes a light incident surface 371 on which the image light is incident from the second lens 36, and a surface 372 on the opposite side to the light incident surface 371. The light incident surface 371 is a reflective surface in the present embodiment.

[0079] The optical path changing member 37 changes the traveling direction of the image light emitted from the second lens 36 and incident on the light incident surface 371 by 90 degrees, and guides the image light to the projection lens 38 .

[0080] [Structure of projection lens]

[0081] The projection lens 38 projects the image light incident from the optical path changing member 37. Although not shown in the figure, the projection lens 38 can be configured as a lens group including a plurality of lenses and a lens barrel that accommodates the plurality of lenses. The portion of the projection lens 38 on the light emitting side is connected to the outer casing 2A, and the portion of the projection lens 38 on the light emitting side is exposed to the outside of the outer casing 2A.

[0082] [Structure of the retainer]

[0083] The holder 4A is a holding member that holds an optical element. In the present embodiment, the holder 4A includes a first holder 4A1 and a second holder 4A2.

[0084] [Structure of the first retainer]

[0085] The first holder 4A1 holds the base member 32, the reflector 33, the first lens 34, the incident-side polarizing plate 351, and the liquid crystal panel 353. That is, the first holder 4A1 holds the incident-side polarizing plate 351 between the first lens 34 and the liquid crystal panel 353. In other words, the first holder 4A1 accommodates the light source 31, the reflector 33, the first lens 34, the incident-side polarizing plate 351, and the liquid crystal panel 353.

[0086] The first holder 4A1 is formed in a cylindrical shape, and the base member 32 is fixed at one end, and the image forming unit 352 is fixed at the other end, thereby sealing the first space SA1 between the base member 32 and the light incident surface of the image forming unit 352. The light source 31, the reflector 33, the first lens 34, the incident side polarizing plate 351, and the liquid crystal panel 353 are arranged in the first space SA1. The incident side polarizing plate 351 and the liquid crystal panel 353 are separated from each other in a manner that a part of the first space SA1 exists.

[0087] In other words, the first holder 4A1 holds the first lens 34 and the incident side end of the image forming unit 352 to seal the space between the light emitting surface 342 of the first lens 34 and the light incident surface 3521 of the image forming unit 352 .

[0088] The first lens 34 and the incident side polarizing plate 351 are preferably fixed to the inner surface of the first holder 4A1 at a pair of ends. In this case, a gap is provided between the end intersecting the pair of ends and the inner surface of the first holder 4A1, so that the first cooling medium described later can form convection through the gap.

[0089] The first holder 4A1 has a first heat receiving surface 4A11 , a first heat dissipating surface 4A12 , and first heat dissipating fins 4A13 .

[0090] The first heat receiving surface 4A11 is provided inside the first holder 4A1. The first heat receiving surface 4A11 constitutes at least a part of the inner surface of the first holder 4A1 and is exposed inside the first holder 4A1. The first heat receiving surface 4A11 receives heat from the gas in the first space SA1.

[0091] The first heat dissipation surface 4A12 is provided outside the first holder 4A1. The first heat dissipation surface 4A12 constitutes at least a portion of the outer surface of the first holder 4A1 and is exposed outside the first holder 4A1. The first heat dissipation surface 4A12 dissipates heat received by the first heat receiving surface 4A11.

[0092] The first heat sink 4A13 is provided on the first heat sink surface 4A12. The first heat sink 4A13 is composed of at least one heat sink, and dissipates heat transferred to the first heat sink surface 4A12. In addition, heat dissipation paint may be applied to the first heat sink 4A13.

[0093] The first space SA1 inside the first holder 4A1 is filled with the first coolant. The first coolant absorbs heat from the heat source HS disposed in the first space SA1, convects in the first space SA1, and transfers the absorbed heat to the first heat receiving surface 4A11.

[0094] As the first cooling medium, for example, any of gas refrigerants such as helium and hydrogen and liquid refrigerants such as hydrofluoroethers can be used.

[0095] In this embodiment, as described above, the light source 31, the light incident surface 3511 and the light exit surface 3512 of the incident side polarizer 351 of the image forming unit 352, and the light incident surface 3521 of the liquid crystal panel 353 of the image forming unit 352 are exposed in the first space SA1, and the light source 31, the incident side polarizer 351 and the liquid crystal panel 353 are the heat source HS.

[0096] Therefore, the first cooling medium can contact the light source 31, the light incident surface 3511, the light exit surface 3512, and the light incident surface 3531, respectively, and the first cooling medium absorbs heat from the light source 31, the light incident surface 3511, the light exit surface 3512, and the light incident surface 3531, respectively. That is, the first cooling medium absorbs heat from the light source 31, the incident side polarizer 351, and the liquid crystal panel 353. The first cooling medium with heat convects inside the first space SA1 and transfers the heat to the first heating surface 4A11. As described above, the heat received by the first heating surface 4A11 is transferred to the first heat dissipation surface 4A12, and dissipated to the outside of the first holder 4A1 through the first heat dissipation surface 4A12 and the first heat sink 4A13.

[0097] [Structure of the Second Cage]

[0098] The second holder 4A2 holds the emission side end of the image forming unit 352 and the second lens 36. The second holder 4A2 is formed in a cylindrical shape, and the image forming unit 352 is fixed at one end, and the second lens 36 is fixed at the other end, thereby sealing the second space SA2 between the light emission surface 3522 of the image forming unit 352 and the light incident surface 361 of the second lens 36. That is, the second holder 4A2 seals the second space SA2 between the light emission surface 3552 of the emission side polarizing plate 355 and the light incident surface 361 of the second lens 36.

[0099] The second holder 4A2 has a second heat receiving surface 4A21, a second heat dissipating surface 4A22, and second heat dissipating fins 4A23.

[0100] The second heat receiving surface 4A21 is provided inside the second holder 4A2. The second heat receiving surface 4A21 constitutes at least a part of the inner surface of the second holder 4A2 and is exposed inside the second holder 4A2. The second heat receiving surface 4A21 receives heat from the gas in the second space SA2.

[0101] The second heat dissipation surface 4A22 is provided outside the second holder 4A2. The second heat dissipation surface 4A22 constitutes at least a portion of the outer surface of the second holder 4A2 and is exposed outside the second holder 4A2. The second heat dissipation surface 4A22 dissipates heat received by the second heat receiving surface 4A21.

[0102] The second heat sink 4A23 is provided on the second heat sink surface 4A22. The second heat sink 4A23 is composed of at least one heat sink, and dissipates heat transferred to the second heat sink surface 4A22. In addition, the second heat sink 4A23 may be coated with heat dissipation paint.

[0103] The second space SA2 inside the second holder 4A2 is filled with a second coolant. The second coolant absorbs heat from the heat source HS disposed in the second space SA2, convects in the second space SA2, and transfers the absorbed heat to the second heat receiving surface 4A21.

[0104] As the second cooling medium, similarly to the first cooling medium, any of gaseous cooling mediums such as helium and hydrogen and liquid cooling mediums such as hydrofluoroethers can be used. The first cooling medium and the second cooling medium may be the same type of cooling medium or different types.

[0105] In this embodiment, as described above, the light exit surface 3522 of the image forming unit 352 and the light incident surface 361 of the second lens 36 are exposed in the second space SA2. That is, the light exit surface 3552 of the exit-side polarizing plate 355 and the light incident surface 361 of the second lens 36 are exposed inside the second space SA2. The exit-side polarizing plate 355 is a heat source HS.

[0106] Therefore, the second cooling medium can contact the light exit surface 3552 and the light incident surface 361, respectively. Therefore, the second cooling medium absorbs heat from the light exit surface 3552 and the light incident surface 361, respectively. That is, the second cooling medium absorbs heat from the exit side polarizer 355 and the second lens 36. The hot second cooling medium convects inside the second space SA2 and transfers the heat to the second heating surface 4A21. As described above, the heat received on the second heating surface 4A21 is transferred to the second heat dissipation surface 4A22, and dissipated to the outside of the second holder 4A2 through the second heat dissipation surface 4A22 and the second heat sink 4A23.

[0107] [Power supply structure]

[0108] The power source 5 is disposed inside the outer casing 2A, transforms power supplied from the outside, and supplies the transformed power to each component of the projector 1A. For example, the power source 5 supplies power to the light source 31, the liquid crystal panel 353, and a control unit (not shown).

[0109] Such a power source 5 is one of the heat sources HS of the projector 1A.

[0110] [Structure of heat transfer components]

[0111] The heat transfer member 6 transfers the heat of the light source 31 to the cooling gas flowing in the outer casing 2A. The heat transfer member 6 includes a heat transport member 61 and a heat dissipation member 62 .

[0112] The heat transport member 61 transfers the heat of the light source 31 transferred to the base member 32 to the heat dissipation member 62. One end of the heat transport member 61 is connected to the base member 32, and the other end of the heat transport member 61 is connected to the heat dissipation member 62. The heat transport member 61 may be composed of, for example, a heat pipe.

[0113] The heat dissipating member 62 dissipates the heat of the light source 31 transported by the heat transporting member 61. Specifically, the heat dissipating member 62 transfers the heat of the light source 31 transported to the cooling gas flowing in the outer casing 2A. The heat dissipating member 62 may be constituted by a radiator, for example.

[0114] In the present embodiment, the heat dissipating member 62 is disposed in the vicinity of the exhaust port 2A6 in the outer casing 2A and is disposed at a position where the cooling gas is circulated by the cooling fan 7 .

[0115] [Cooling fan structure]

[0116] The cooling fan 7 introduces cooling gas into the outer case 2A through the introduction port 2A5, flows the introduced cooling gas in the outer case 2A, and discharges the cooling gas to the outside of the outer case 2A through the discharge port 2A6. The cooling fan 7 includes a first cooling fan 72 and a second cooling fan 71.

[0117] The second cooling fan 71 is equivalent to the second fan described later. The second cooling fan 71 is arranged at a position closer to the inlet 2A5 side than the first cooling fan 72. The second cooling fan 71 introduces the gas outside the outer casing 2A as cooling gas into the inside of the outer casing 2A through the inlet 2A5, and sends it to the first holder 4A1 and the second holder 4A2. Thus, the cooling gas flows to the first heat sink 4A13 and the second heat sink 4A23.

[0118] The first cooling fan 72 is disposed closer to the outlet 2A6 than the second cooling fan 71. The first cooling fan 72 draws the cooling gas in the outer case 2A, flows through the power source 5 and the heat sink 62, and then discharges the cooling gas to the outside of the outer case 2A from the outlet 2A6.

[0119] [Cooling of heat source]

[0120] As described above, in the first space SA1, the light source 31, the light incident surface 3511 and the light exit surface 3512 of the incident side polarizer 351, and the light incident surface 3531 of the liquid crystal panel 353 are exposed in a manner that they can contact the first cooling medium. Therefore, the heat of the light source 31, the incident side polarizer 351, and the liquid crystal panel 353 is absorbed by the first cooling medium, and the light source 31, the incident side polarizer 351, and the liquid crystal panel 353 are cooled.

[0121] When the heated first cooling medium convects due to the temperature difference in the first space SA1 and reaches the first heat receiving surface 4A11, the heat of the first cooling medium is received by the first heat receiving surface 4A11. Thus, the first cooling medium is cooled.

[0122] The heat transferred to the first heat receiving surface 4A11 is transferred to the first heat dissipating surface 4A12 and the first heat dissipating fins 4A13.

[0123] In the second space SA2, the light exit surface 3552 of the exit-side polarizing plate 355 and the light incident surface 361 of the second lens 36 are exposed in a manner that can contact the second cooling medium. Therefore, the heat of the exit-side polarizing plate 355 is absorbed by the second cooling medium, and the exit-side polarizing plate 355 is cooled. In addition, the heat transferred from the exit-side polarizing plate 355 to the second cooling medium includes the heat transferred from the liquid crystal panel 353 to the exit-side polarizing plate 355.

[0124] When the heated second cooling medium convects due to the temperature difference in the second space SA2 and reaches the second heat receiving surface 4A21, the heat of the second cooling medium is received by the second heat receiving surface 4A21. Thus, the second cooling medium is cooled.

[0125] The heat transferred to the second heat receiving surface 4A21 is transferred to the second heat dissipating surface 4A22 and the second heat dissipating fins 4A23.

[0126] When the second cooling fan 71 is driven, the cooling gas introduced into the outer casing 2A from the introduction port 2A5 flows through the first holder 4A1 and the second holder 4A2. The first holder 4A1 dissipates the heat received by the first heat receiving surface 4A11 to the cooling gas through the first heat dissipation surface 4A12 and the first heat dissipation fins 4A13. The second holder 4A2 dissipates the heat received by the second heat receiving surface 4A21 to the cooling gas through the second heat dissipation surface 4A22 and the second heat dissipation fins 4A23.

[0127] Thereby, the first heat dissipation surface 4A12, the first heat dissipation fins 4A13, the second heat dissipation surface 4A22, and the second heat dissipation fins 4A23 are cooled.

[0128] When the first cooling fan 72 is driven, the cooling gas flows through the power source 5 disposed on the air intake side of the first cooling fan 72 while the first cooling fan 72 sucks the cooling gas in the outer casing 2A. As a result, the power source 5 is cooled. In addition, a portion of the cooling gas flowing through the power source 5 is the cooling gas flowing through at least one of the first holder 4A1 and the second holder 4A2.

[0129] The first cooling fan 72 delivers the sucked cooling gas to the heat dissipation member 62. Thus, the heat dissipation member 62 transfers the heat of the light source 31 transferred via the base member 32 and the heat transfer member 61 to the circulating cooling gas. The cooling gas that flows through the heat dissipation member 62 and to which the heat of the light source 31 is transferred is discharged to the outside of the outer casing 2A from the discharge port 2A6.

[0130] [Effects of the First Embodiment]

[0131] The projector 1A according to the present embodiment described above provides the following effects.

[0132] The projector 1A includes an exterior casing 2A, a light source 31 , a first lens 34 , an image forming unit 352 , a second lens 36 , a projection lens 38 , a first holder 4A1 , and a second holder 4A2 .

[0133] The light source 31 emits white light. The first lens 34 converges the white light emitted from the light source 31. One image forming unit 352 is provided in the projector 1A. The image forming unit 352 emits image light obtained by modulating the white light incident from the first lens 34. The second lens 36 converges the image light emitted from the image forming unit 352. The projection lens 38 projects the image light incident from the second lens 36. The outer casing 2A accommodates the light source 31, the first lens 34, the image forming unit 352, the second lens 36, and the projection lens 38.

[0134] The first holder 4A1 has a first heat receiving surface 4A11 therein. The first holder 4A1 holds the first lens 34 and the incident side end of the image forming unit 352. The first holder 4A1 seals a first space SA1 including a light emitting surface 342 of the first lens 34 and a light incident surface 3521 of the image forming unit 352.

[0135] The second holder 4A2 has a second heat receiving surface 4A21 therein. The second holder 4A2 holds the light exit side end of the image forming unit 352 and the second lens 36. The second holder 4A2 seals the second space SA2 including the light exit surface 3522 of the image forming unit 352 and the light incident surface 361 of the second lens 36.

[0136] The first space SA1 is filled with a first cooling medium. The first cooling medium absorbs heat from the image forming unit 352, convects in the first space SA1, and transfers the heat to the first heating surface 4A11. The first heating surface 4A11 is the heating surface exposed in the first space SA1 filled with the first cooling medium, among the first heating surface 4A11 and the second heating surface 4A21.

[0137] The second space SA2 is filled with a second cooling medium. The second cooling medium absorbs heat from the image forming unit 352, convects in the second space SA2, and transfers the heat to the second heating surface 4A21. The second heating surface 4A21 is the heating surface exposed in the second space SA2 filled with the second cooling medium, between the first heating surface 4A11 and the second heating surface 4A21.

[0138] The outer peripheral surface 3523 of the image forming unit 352 is exposed inside the outer casing 2A.

[0139] According to such a structure, the image forming unit 352 as the heat source HS is held by the first holder 4A1 that seals the first space SA1 on the light incident side of the image forming unit 352 and the second holder 4A2 that seals the second space SA2 on the light emitting side of the image forming unit 352. The first cooling medium filled in the first space SA1 and the second cooling medium filled in the second space SA2 absorb the heat of the image forming unit 352 and convect, and are stirred inside the first space SA1 and inside the second space SA2, and dissipate the absorbed heat to the first heating surface 4A11 and the second heating surface 4A21. Thus, the heat of the image forming unit 352 can be dissipated to the first holder 4A1 and the second holder 4A2, and the image forming unit 352 can be cooled. Therefore, the cooling efficiency of the image forming unit 352 as the heat source can be improved.

[0140] Furthermore, since the light incident surface 3521 and the light emitting surface 3522 of the image forming unit 352 are sealed by the first holder 4A1 and the second holder 4A2, it is possible to suppress dust from being attached to the image forming unit 352. This can suppress the shadow of dust from being cast on the projected image.

[0141] Furthermore, since the outer peripheral surface 3523 of the image forming unit 352 is exposed inside the outer casing 2A, the wiring of the image forming unit 352 can extend to the space inside the outer casing 2A, and therefore, there is no need to seal the wiring. Therefore, since there is no need for a sealing structure for the wiring, the brightness of the light source 31 can be increased while maintaining the size of the projector 1A, thereby increasing the brightness of the projected image.

[0142] In the projector 1A, the image forming unit 352 includes one liquid crystal panel 353 , one color filter 354 , and one light-exiting-side polarizing plate 355 .

[0143] The color filter 354 is arranged on the light output side of the liquid crystal panel 353, and the image light output from the liquid crystal panel 353 passes through the color filter 354. The output-side polarizing plate 355 is arranged on the light output side of the color filter 354, and the image light having passed through the color filter 354 passes through the output-side polarizing plate 355.

[0144] The second space SA2 is filled with the second cooling medium.

[0145] According to such a structure, full-color image light can be formed by one liquid crystal panel 353. In addition, part of the heat generated by the liquid crystal panel 353 can be transferred to the second cooling medium in the second space SA2 via the color filter 354 and the output-side polarizing plate 355. Therefore, the liquid crystal panel 353 can be cooled.

[0146] The projector 1A includes an incident-side polarizing plate 351, which is disposed on the light incident side of the liquid crystal panel 353, and the light incident on the liquid crystal panel 353 passes through the incident-side polarizing plate 351. The first holder 4A1 holds the incident-side polarizing plate 351 between the first lens 34 and the liquid crystal panel 353. The incident-side polarizing plate 351 and the liquid crystal panel 353 are separated from each other in a manner that a part of the first space SA1 exists. The first space SA1 is filled with a first cooling medium.

[0147] Here, the light source 31 emits white light including p-polarized light and s-polarized light. The incident-side polarizing plate 351 transmits one of the p-polarized light and the s-polarized light and absorbs the other polarized light, thus becoming a heat source HS that generates heat due to incident light.

[0148] On the other hand, the first cooling medium filled in the first space SA1 can cool the incident-side polarizing plate 351 in addition to the liquid crystal panel 353. Therefore, the incident-side polarizing plate 351 and the liquid crystal panel 353 can be cooled efficiently.

[0149] In the projector 1A, the light incident surface 3511 of the incident-side polarizing plate 351 is exposed in the first space SA1.

[0150] According to such a configuration, the light incident surface 3511 and the light exit surface 3512 of the incident-side polarizing plate 351 are exposed in the first space SA1 , so that the incident-side polarizing plate 351 can be efficiently cooled by the first cooling medium.

[0151] In the projector 1A, the first holder 4A1 accommodates the light source 31 in a sealed state.

[0152] According to such a configuration, the first cooling medium filled in the first space SA1 can also flow through the light source 3. Therefore, the light source 31 can be cooled by the first cooling medium.

[0153] In the projector 1A, the first holder 4A1 has the first heat sink 4A13 exposed in the internal space of the outer casing 2A, and the second holder 4A2 has the second heat sink 4A23 exposed in the internal space of the outer casing 2A. The first heat sink 4A13 and the second heat sink 4A23 correspond to heat sinks.

[0154] According to this structure, the heat of the heat source HS disposed inside each holder 4A1, 4A2 can be dissipated to the outside of each holder 4A1, 4A2 through each heat sink 4A13, 4A23. Therefore, the cooling efficiency of the heat source HS disposed inside the holder 4A1, 4A2 can be improved.

[0155] The projector 1A includes a base member 32 on which the light source 31 is arranged, and a heat dissipation member 62 that transfers heat of the light source 31 via the base member 32 .

[0156] According to such a configuration, the heat of the light source 31 transmitted via the base member 32 can be dissipated by the heat dissipation member 62. Therefore, the light source 31 can be cooled.

[0157] The projector 1A includes a first cooling fan 72 disposed inside the outer casing 2A. The first cooling fan 72 corresponds to a first fan.

[0158] The outer casing 2A has an inlet 2A5 for introducing gas from the outside of the outer casing 2A into the inside of the outer casing 2A, and an outlet 2A6 for discharging gas flowing inside the outer casing 2A to the outside of the outer casing 2A. The heat dissipation member 62 is arranged at a position closer to the outlet 2A6 than the inlet 2A5. The first cooling fan 72 allows the gas introduced into the inside of the outer casing 2A to flow to the outlet 2A6 via the heat dissipation member 62.

[0159] According to such a configuration, the first cooling fan 72 allows the gas introduced into the outer casing 2A to flow through the heat sink 62. Therefore, the heat sink 62 can accelerate the heat dissipation of the light source 31, thereby improving the cooling efficiency of the light source 31.

[0160] The projector 1A includes a power source 5 disposed on the air intake side of the first cooling fan 72. The power source 5 supplies power to at least one of the light source 31 and the image forming unit 352. In the present embodiment, the power source 5 supplies power to the light source 31 and the image forming unit 352 separately.

[0161] According to such a configuration, the cooling gas introduced into the outer casing 2A from the introduction port 2A5 can flow through the power source 5 by the first cooling fan 72. Therefore, by driving the first cooling fan 72, the power source 5 and the light source 31 can be cooled.

[0162] The projector 1A includes a second cooling fan 71 disposed inside the outer casing 2A at a position closer to the inlet 2A5 than the outlet 2A6. The second cooling fan 71 corresponds to a second fan. The second cooling fan 71 allows the cooling gas introduced into the inner part of the outer casing 2A to flow through the first holder 4A1 and the second holder 4A2.

[0163] According to such a configuration, the cooling gas introduced into the interior of the outer casing 2A can be circulated through the first holder 4A1 and the second holder 4A2 by the second cooling fan 71. Therefore, the heat dissipation efficiency of the heat source HS disposed inside each of the holders 4A1 and 4A2 can be improved, and the cooling efficiency of the heat source HS can be improved.

[0164] In the projector 1A, the first cooling medium is any one of helium gas, hydrogen gas, and hydrofluoroether liquid. The same applies to the second cooling medium.

[0165] By using the above-mentioned cooling medium with high thermal conductivity or cooling medium with high specific heat as the first cooling medium filled in the first holder 4A1 and the second cooling medium filled in the second holder 4A2 , the cooling performance of the image forming unit 352 can be improved.

[0166] [First Modification of First Embodiment]

[0167] The holder 4A included in the projector 1A described above includes a first holder 4A1 connecting the base member 32 and the incident side end of the liquid crystal panel 353 included in the image forming unit 352, and a second holder 4A2 connecting the output side polarizing plate 355 of the image forming unit 352 and the second lens 36. However, the present invention is not limited thereto, and the holder may include a third holder connecting the second lens 36, the optical path changing member 37, and the projection lens 38 in addition to the first holder 4A1 and the second holder 4A2.

[0168] Figure 2 4B is a schematic diagram showing a holder 4B which is a modification of the holder 4A.

[0169] For example, projector 1B has Figure 2 The holder 4B shown in the figure replaces the holder 4A of the projector 1A, and has the same structure as the projector 1A except that it has this structure.

[0170] The holder 4B includes a first holder 4A1 and a second holder 4A2 similarly to the holder 4A, and further includes a third holder 4B3.

[0171] The third holder 4B3 holds the emission side end of the second lens 36, the optical path changing member 37, and the incident side end of the projection lens 38, and seals the third space SB3 between the light emission surface 362 of the second lens 36 and the projection lens 38. That is, the third holder 4B3 has the third space SB3 for accommodating the second lens 36, the optical path changing member 37, and the projection lens 38.

[0172] The third holder 4B3 has a third heat receiving surface 4B31, a third heat dissipating surface 4B32, and third heat dissipating fins 4B33.

[0173] The third heat receiving surface 4B31 is provided inside the third holder 4B3. The third heat receiving surface 4B31 constitutes at least a part of the inner surface of the third holder 4B3 and is exposed inside the third holder 4B3. The third heat receiving surface 4B31 receives heat from the gas in the third space SB3.

[0174] The third heat dissipation surface 4B32 is provided outside the third holder 4B3. The third heat dissipation surface 4B32 constitutes at least a part of the outer surface of the third holder 4B3 and is exposed outside the third holder 4B3. The third heat dissipation surface 4B32 dissipates the heat received by the third heat receiving surface 4B31.

[0175] The third heat sink 4B33 is provided on the third heat sink surface 4B32. The third heat sink 4B33 is composed of at least one heat sink, and dissipates the heat transferred to the third heat sink surface 4B32. In addition, the third heat sink 4B33 may not be provided.

[0176] The third space SB3 may be filled with a third coolant that is the same coolant as the first coolant or the second coolant, or may not be filled with the third coolant.

[0177] The projector 1B including the holder 4B has the following effects in addition to the same effects as those of the projector 1A including the holder 4A.

[0178] That is, among the light source 31, reflector 33, first lens 34, light modulator 35, second lens 36, optical path changing member 37, and projection lens 38 that constitute the image projection unit 3 and contribute to image formation and image projection, the first space SA1, the second space SA2, and the third space SB3 through which light passes are sealed by the first holder 4A1, the second holder 4A2, and the third holder 4B3. Therefore, it is possible to suppress the influence of dust on the image formation and image projection of the image projection unit 3. Therefore, the projector 1B can stably project image light.

[0179] [Second Modification of First Embodiment]

[0180] In the above-mentioned projector 1A, the inlet 2A5 is provided on the left side 2A3 of the outer casing 2A, and the outlet 2A6 is provided on the right side 2A4 of the outer casing 2A. That is, the inlet 2A5 and the outlet 2A6 are provided on the side surfaces opposite to each other in the outer casing 2A. However, the present invention is not limited thereto, and the positions of the inlet 2A5 and the outlet 2A6 can be appropriately changed.

[0181] Figure 3 2 is a schematic diagram showing an outer casing 2C which is a modification of the outer casing 2A.

[0182] For example, the projector 1C includes a Figure 3 The projector 1A has the same structure as that of the projector 1A except for the outer casing 2C shown.

[0183] The outer casing 2C has the same structure and function as the outer casing 2A except that it has a discharge port 2C6 instead of the discharge port 2A6.

[0184] The exhaust port 2C6 is provided on the front surface 2A1. That is, the exhaust port 2C6 is provided on the side surface of the outer case 2C that intersects the left side surface 2A3 provided with the introduction port 2A5. The exhaust port 2C6 exhausts the cooling gas inside the outer case 2A to the outside of the outer case 2C.

[0185] In the projector 1C having such an outer casing 2C, the first cooling fan 72 as the first fan is also arranged so that the heat sink 62 and the exhaust port 2C6 are located in the delivery direction of the cooling gas of the first cooling fan 72. Thus, the cooling gas that flows along the first holder 4A1, the second holder 4A2, and the power source 5 and flows to the heat sink 62 can be discharged from the exhaust port 2C6 to the outside of the outer casing 2C.

[0186] In addition, since the discharge port 2A6 is not provided on the right side surface 2A4, the right side surface 2A4 can be used as a bottom surface provided on the floor.

[0187] [Second embodiment]

[0188] Next, a second embodiment of the present invention will be described.

[0189] The projector of this embodiment has the same structure as the projector 1A of the first embodiment, but the structure of the first holder is different. In detail, the optical components stored inside the first holder of this embodiment and the first holder 4A1 are different. In addition, in the following description, the same or substantially the same parts as those already described are marked with the same reference numerals and the description is omitted.

[0190] [Schematic structure of the projector]

[0191] Figure 4 1 is a schematic diagram showing the structure of a projector 1D according to the present embodiment.

[0192] like Figure 4 As shown in FIG. 1 , the projector 1D according to the present embodiment includes a holder 4D instead of the holder 4A, and has the same structure and function as the projector 1A according to the first embodiment except for this.

[0193] [Structure of the retainer]

[0194] The holder 4D has a first holder 4D1 instead of the first holder 4A1 of the projector 1A of the first embodiment, and has the same structure and function as the holder 4A of the first embodiment. That is, the holder 4D includes the first holder 4D1 and the second holder 4A2. In addition, the holder 4D may also include a third holder 4B3 which is a modification of the first embodiment.

[0195] The first holder 4D1 holds the emission side end of the first lens 34 and the incident side end of the image forming unit 352. Specifically, the first holder 4D1 connects the emission side end of the first lens 34 and the incident side end of the image forming unit 352 in a state where the incident side polarizing plate 351 is stored inside. The incident side end of the image forming unit 352 is composed of the incident side end of the liquid crystal panel 353.

[0196] The first holder 4D1 seals the first space SD1 including the light exit surface 342 of the first lens 34 and the light incident surface 3521 of the image forming unit 352. As described above, the light incident surface 3521 is formed by the light incident surface 3531 of the liquid crystal panel 353.

[0197] Therefore, the light output surface 342 of the first lens 34 , the light input surfaces 3511 and 3512 of the incident-side polarizing plate 351 , and the light input surface 353 of the liquid crystal panel 353 are exposed in the first space SD1 .

[0198] The first holder 4D1 has a first heat receiving surface 4D11 , a first heat dissipating surface 4D12 , and first heat dissipating fins 4D13 .

[0199] The first heat receiving surface 4D11 is provided inside the first holder 4D1. The first heat receiving surface 4D11 constitutes at least a part of the inner surface of the first holder 4D1 and is exposed inside the first holder 4D1. The first heat receiving surface 4D11 receives heat from the gas in the first space SD1.

[0200] The first heat dissipation surface 4D12 is provided outside the first holder 4D1. The first heat dissipation surface 4D12 constitutes at least a portion of the outer surface of the first holder 4D1 and is exposed to the outside of the first holder 4D1. The first heat dissipation surface 4D12 dissipates heat received by the first heat receiving surface 4D11.

[0201] The first heat sink 4D13 is provided on the first heat sink surface 4D12. The first heat sink 4D13 is composed of at least one heat sink, and dissipates heat transferred to the first heat sink surface 4D12. In addition, the first heat sink 4D13 may be coated with heat dissipation paint.

[0202] The first space SD1 is filled with the same first cooling medium as the first cooling medium filled in the first space SA1. The first cooling medium absorbs heat from the structure in the first space SD1, convects inside the first space SD1, and transfers heat to the first heating surface 4D11. That is, the first cooling medium absorbs heat from the incident side polarizing plate 351 and the liquid crystal panel 353 arranged in the first space SD1, convects inside the first space SD1, and transfers heat to the first heating surface 4D11.

[0203] The heat received by the first heat receiving surface 4D11 is dissipated to the outside of the first holder 4D1 through the first heat dissipating surface 4D12 and the first heat dissipating fins 4D13 , and is transferred to the cooling gas flowing through the second cooling fan 71 .

[0204] On the other hand, the outer surface of the base member 32 of the light source 31 and the outer surface of the reflector 33 are exposed inside the outer casing 2A. Therefore, part of the heat transferred to the base member 32 is dissipated from the outer surface of the base member 32 into the outer casing 2A.

[0205] The projector 1D according to the present embodiment described above achieves the same effects as the projector 1A according to the first embodiment.

[0206] [Third Embodiment]

[0207] Next, a third embodiment of the present invention will be described.

[0208] The projector of this embodiment has the same structure as the projector 1D of the second embodiment, but the difference is that the structure of the second holder is different and a circulation fan is further provided. In addition, in the following description, the same or substantially the same parts as those already described are marked with the same reference numerals and the description is omitted.

[0209] [Schematic structure of the projector]

[0210] Figure 5 Schematic diagram showing the structure of a projector 1E according to this embodiment. Figure 5 In the figure, the second cooling fan 71 is omitted.

[0211] like Figure 5 As shown, the projector 1E of this embodiment includes a holder 4E instead of the holder 4D of the projector 1D of the second embodiment and includes a circulation fan 8 , and has the same configuration and function as the projector 1D of the second embodiment.

[0212] [Structure of the retainer]

[0213] The holder 4E has the same structure and function as the holder 4D of the second embodiment except that the holder 4E2 is replaced with the second holder 4A2 of the first and second embodiments. That is, the holder 4E includes the first holder 4D1 and the second holder 4E2.

[0214] In addition, the holder 4E may include the first holder 4A1 of the first embodiment instead of the first holder 4D1, or may include the third holder 4B3 described above.

[0215] The second holder 4E2 holds the exit-side end of the image forming unit 352 and the second lens 36 similarly to the second holder 4A2 of the first embodiment, and seals the second space SE2 including the light exit surface 3552 of the exit-side polarizing plate 355 constituting the light exit surface 3522 of the image forming unit 352 and the light incident surface 361 of the second lens 36. Specifically, the second holder 4E2 connects the exit-side end of the image forming unit 352 and the incident-side end of the projection lens 38, and seals the second space SE2 which is the space from the exit-side end of the image forming unit 352 to the incident-side end of the projection lens 38. In other words, the second retainer 4E2 has a second space SE2, and the light output surface 3552 of the output side polarizer 355, the second lens 36, the optical path changing component 37 and the light incident surface of the projection lens 38 are exposed inside the second space SE2, and the second lens 36 and the optical path changing component 37 are arranged in the second space SE2.

[0216] The second holder 4E2 has a second heat receiving surface 4E21, a second heat dissipating surface 4E22, and second heat dissipating fins 4E23, similarly to the second holder 4A2.

[0217] The second heat receiving surface 4E21 is provided inside the second holder 4E2. The second heat receiving surface 4E21 constitutes at least a part of the inner surface of the second holder 4E2 and is exposed inside the second holder 4E2. The second heat receiving surface 4E21 receives heat from the gas in the second space SE2.

[0218] The second heat dissipation surface 4E22 is provided outside the second holder 4E2. The second heat dissipation surface 4E22 constitutes at least a portion of the outer surface of the second holder 4E2 and is exposed outside the second holder 4E2. The second heat dissipation surface 4E22 dissipates the heat received by the second heat receiving surface 4E21.

[0219] The second heat sink 4E23 is provided on the second heat sink surface 4E22. The second heat sink 4E23 is composed of at least one fin and dissipates the heat transferred to the second heat sink surface 4E22. Figure 5 In consideration of easy observation, the plurality of fins constituting the second heat sink 4E23 are arranged along the flow direction of the cooling gas, but it is preferred that the plurality of fins extend along the flow direction of the cooling gas. In addition, the second heat sink 4E23 may be coated with heat dissipation paint.

[0220] The second space SE2 inside the second retainer 4E2 is filled with the same second coolant as the second coolant filled in the second space SA2. The second coolant absorbs heat from the structure in the second space SE2, performs convection inside the second space SE2, and transfers the heat to the second heat receiving surface 4E21.

[0221] A circulation fan 8 is disposed in such a second space SE2.

[0222] [Structure of circulation fan]

[0223] The circulation fan 8 is disposed inside the second holder 4E2. Specifically, the circulation fan 8 is provided between a surface 372 of the optical path changing member 37 opposite to the light incident surface 371 and an inner surface of the second holder 4E2 facing the surface 372.

[0224] The circulation fan 8 circulates the second cooling medium in the second space SE2. For example, the circulation fan 8 sucks the second cooling medium filled in the second space SE2 and sends it toward the image forming unit 352. The second cooling medium sent to the image forming unit 352 flows between the image forming unit 352 and the second lens 36. That is, the second cooling medium flows between the light exit surface 3552 of the exit-side polarizing plate 355 and the light incident surface 361 of the second lens 36, in the direction approaching the projection lens 38, along the light exit surface 3552 and the light incident surface 361. The light exit side portion of the image forming unit 352 is cooled by the second cooling medium that circulates in this way.

[0225] The second cooling medium flowing between the image forming unit 352 and the second lens 36 is cooled while flowing along the second heat receiving surface 4E21 in the second holder 4E2 , and is sucked again by the circulation fan 8 .

[0226] On the other hand, the heat received by the second heat receiving surface 4E21 is transferred to the cooling gas flowing along the second holder 4E2 via the second heat dissipating surface 4E22 and the second heat dissipating fins 4E23.

[0227] When the projector 1D is configured in such a manner that the projection lens 38 is located above the light source 31, the second cooling medium that cools the image forming unit 352 convects toward the upper side of the image forming unit 352 due to the heat, and becomes easy to contact the second heat receiving surface 4E21. As a result, the second heat receiving surface 4E21 easily absorbs heat from the second cooling medium, and the second cooling medium can be easily cooled. In addition, the cooled second cooling medium is circulated to the image forming unit 352 again by using the circulation fan 8, thereby improving the cooling efficiency of the image forming unit 352. Furthermore, in such a setting posture of the projector 1E, the left side surface 2A3 becomes the top surface, so the cooling gas introduced into the outer casing 2A from the inlet 2A5 can be easily circulated to the second heat dissipation surface 4E22 and the second heat sink 4E23 above the second retainer 4E2. Therefore, heat transfer from the second heat dissipation surface 4E22 and the second heat dissipation fins 4E23 to the cooling gas can be promoted, and the cooling efficiency of the second cooling medium can be improved, thereby improving the cooling efficiency of the image forming unit 352 .

[0228] [Effects of the third embodiment]

[0229] The projector 1E of the present embodiment described above has the following effects in addition to the same effects as the projector 1A of the first embodiment.

[0230] In the projector 1E, the second holder 4E2 is connected to the incident side end of the projection lens 38 , and seals the area from the emission side end of the image forming unit 352 to the incident side end of the projection lens 38 .

[0231] According to such a configuration, the second cooling medium filling the second space SE2 in the second holder 4E2 can cool the optical components arranged on the optical path from the emission side end of the image forming unit 352 to the incident side end of the projection lens 38 using the cooling medium.

[0232] Furthermore, the second holder 4E2 seals the area from the emission side end of the image forming unit 352 to the incident side end of the projection lens 38, so the second space SE2 is a space from the emission side end of the image forming unit 352 to the incident side end of the projection lens 38. Therefore, the second space SE2 is a relatively large space, and thus the heat capacity of the second space SE2 can be increased. Therefore, the temperature of the cooling medium in the second space SE2 can be suppressed from rising sharply due to the heat of the heat source HS, and the optical element in the second space SE2 can be effectively cooled.

[0233] The projector 1E includes an optical path changing member 37 and a circulation fan 8 .

[0234] The optical path changing member 37 is disposed between the second lens 36 and the incident side end of the projection lens 38. The optical path changing member 37 changes the traveling direction of the light emitted from the second lens 36.

[0235] The circulation fan 8 is disposed between the surface 372 on the opposite side of the light incident surface 371 and the inner surface of the second holder 4E2 in the optical path changing member 37. The circulation fan 8 circulates the second cooling medium filled in the second space SE2.

[0236] The optical path changing member 37 and the circulation fan 8 are arranged inside the second holder 4E2.

[0237] According to such a structure, a circulation fan 8 for circulating the second cooling medium can be arranged in the dead space between the optical path changing member 37 and the inner surface of the second holder 4E2. Therefore, in addition to improving the cooling performance of the image forming unit 352, even if the circulation fan 8 is arranged, the size of the projector 1E can be suppressed.

[0238] [Variations of Embodiments]

[0239] The present invention is not limited to the above-described embodiments, and modifications and improvements within the scope that can achieve the object of the present invention are included in the present invention.

[0240] In the above-mentioned embodiments, the outer peripheral surface 3523 of the image forming unit 352 is exposed inside the outer casing 2A, 2C. That is, the outer peripheral surface of the liquid crystal panel 353 is exposed inside the outer casing 2A, 2C. However, the entire surface of the outer peripheral surface 3523 does not necessarily need to be exposed inside the outer casing 2A, 2C, and the portion of the wiring in the liquid crystal panel 353 that is exposed from the liquid crystal panel 353 can be exposed inside the outer casing 2A, 2C.

[0241] In the first embodiment, the first holder 4A1 holds the base member 32, the reflector 33, the first lens 34, the incident side polarizing plate 351, and the incident side end of the image forming unit 352, and seals the first space SA1 between the base member 32 and the light incident surface 3521 of the image forming unit 352, thereby sealing the space between the light exit surface 342 of the first lens 34 and the light incident surface 3521 of the image forming unit 352. However, the present invention is not limited thereto, and as long as the structure is such that the first lens 34, the incident side polarizing plate 351, and the incident side end of the image forming unit 352 are held and at least the space between the light exit surface 342 of the first lens 34 and the light incident surface 3521 of the image forming unit 352 is sealed, as in the first holder 4D1 of the second embodiment, the first holder may hold other optical components, and may not hold a part of the optical components.

[0242] In the third embodiment described above, the second holder 4E2 holds the end of the image forming unit 352 on the emission side, the second lens 36, the optical path changing member 37, and the end of the projection lens 38 on the incidence side, and seals the second space SE2 between the light emission surface 3522 of the image forming unit 352 and the light incidence surface of the projection lens 38, thereby sealing the space between the light emission surface 3522 of the image forming unit 352 and the light incidence surface 361 of the second lens 36. However, the present invention is not limited thereto, and as long as the second holder 4A2 of the first and second embodiments holds the end of the image forming unit 352 on the emission side and the second lens 36 and seals at least the space between the light emission surface 3522 of the image forming unit 352 and the light incidence surface 361 of the second lens 36, the second holder may hold other optical components, and may not hold a part of the optical components.

[0243] In the above-mentioned embodiments, the first holder 4A1, 4D1 has first heat sinks 4A13, 4D13 in addition to the first heat receiving surfaces 4A11, 4D11 and the first heat dissipating surfaces 4A12, 4D12. The second holder 4A2, 4E2 has second heat sinks 4A23, 4E23 in addition to the second heat receiving surfaces 4A21, 4E21 and the second heat dissipating surfaces 4A22, 4E22. However, the present invention is not limited thereto, and at least one of the first holder and the second holder may not have a heat sink.

[0244] In each of the above embodiments, the image forming unit 352 includes a transmissive liquid crystal panel 353, a color filter 354, and an output-side polarizing plate 355. However, the present invention is not limited thereto. The liquid crystal panel 353 may be a reflective liquid crystal panel that emits image light in a direction opposite to the incident direction of light, instead of a transmissive liquid crystal panel, or may be a light modulating panel other than liquid crystal. Depending on the image forming panel used, the output-side polarizing plate 355 may be omitted.

[0245] Furthermore, the image forming unit 352 may not include the color filter 354 , and as described above, the color filter 354 may be a monochrome filter.

[0246] Furthermore, when the light emitted from the light source 31 and incident on the incident-side polarizing plate 351 is a linearly polarized light, the incident-side polarizing plate 351 may be omitted.

[0247] In the above embodiments, the first lens 34 and the second lens 36 are Fresnel lenses. However, the present invention is not limited thereto, and at least one of the first lens 34 and the second lens 36 may not be a Fresnel lens. Furthermore, for example, the image projection unit 3 may include other optical components in addition to the above optical components.

[0248] In each of the above-mentioned embodiments, the image projection unit 3 includes an optical path changing component 37 that changes the optical path of the image light emitted from the second lens 36 and causes the image light to enter the projection lens 38. However, the present invention is not limited to this, and there may be no optical path changing component 37. In addition, the optical path changing component 37 changes the optical path of the image light by reflecting the incident image light. However, the present invention is not limited to this, and the optical path changing component may also be an optical component such as a prism.

[0249] In the third embodiment, the second holder 4E2 is provided with a circulation fan 8, which is disposed between the inner surface of the second holder 4E2 and the optical path changing member 37 to circulate the second cooling medium. However, the present invention is not limited thereto, and the circulation fan 8 may not be provided. In addition, the number of the circulation fans 8 disposed in the second holder 4E2 is not limited to one, and may be changed appropriately.

[0250] In the above-mentioned embodiments, the projectors 1A, 1D, and 1E include a heat transport member 61 that is thermally conductively connected to the base member 32 that supports the light source 31, and a heat dissipation member 62 that dissipates the heat of the light source 31 transferred from the heat transport member 61. However, the present invention is not limited thereto. For example, when the light source 31 is provided in the heat dissipation member 62, at least one of the base member 32 and the heat transport member 61 may be omitted.

[0251] Furthermore, if the light source 31 can be sufficiently cooled by the cooling gas or the first cooling medium, the heat transport member 61 and the heat dissipation member 62 may not be provided.

[0252] In the above-mentioned embodiments, the projectors 1A, 1D, and 1E include the first cooling fan 72 as the first fan and the second cooling fan 71 as the second fan disposed in the outer casings 2A and 2C. However, the present invention is not limited thereto, and at least one of the first cooling fan 72 and the second cooling fan 71 may not be included.

[0253] Furthermore, when the fan provided in the outer casing is used as a circulation fan for circulating the gas in the outer casing, the outer casing may not have the inlet and the outlet.

[0254] In the above-mentioned embodiments, the projectors 1A, 1D, and 1E include a power supply 5, which is disposed in the outer casing 2A and 2C and supplies power to the light source 31 and the image forming unit 352. However, the power supply 5 does not necessarily need to be disposed inside the outer casing 2A and 2C. In addition, the projector may include a first power supply that supplies power to the light source 31 and a second power supply that supplies power to the image forming unit 352. Furthermore, the power supply 5 may supply power to one of the light source 31 and the image forming unit 352.

[0255] In the above-mentioned embodiments, the exit-side polarizing plate 355 is stacked on the color filter 354 provided on the liquid crystal panel 353, thereby shortening the optical path length. However, the invention is not limited thereto, and the liquid crystal panel 353, the color filter 354, and the exit-side polarizing plate 355 may also be separated from each other. In this case, the second holder may be configured such that one end of the second holder holds the exit-side end of the liquid crystal panel 353, and the light exit surface 3532 of the liquid crystal panel 353 is exposed in the second space.

[0256] In the above embodiments, the first cooling medium and the second cooling medium are any one of helium, hydrogen and hydrofluoroether liquid refrigerants. However, the present invention is not limited thereto, and the type of cooling medium can be appropriately changed, and multiple refrigerants can also be mixed and filled into the frame.

[0257] In the above embodiments, the first retainers 4A1 and 4D1 are filled with the first coolant, and the second retainers 4A2 and 4E2 are filled with the second coolant. However, the present invention is not limited thereto, and the coolant may not be filled in one of the first retainer and the second retainer.

[0258] [Summary of the utility model]

[0259] Below, the summary of the present utility model is attached.

[0260] [Note 1]

[0261] A projector, characterized in that it comprises: a light source that emits white light; a first lens that converges the white light emitted from the light source; an image forming unit that emits image light that is modulated from the white light incident from the first lens; a second lens that converges the image light emitted from the image forming unit; a projection lens that projects the image light incident from the second lens; an outer casing that accommodates the light source, the first lens, the image forming unit, the second lens, and the projection lens; a first holder that has a first heat receiving surface inside, holds the first lens and the incident side end of the image forming unit, and is used to heat the light emitting surface of the first lens and the second lens. A first space included between the light incident surfaces of the image forming unit is sealed; and a second holder, which has a second heating surface inside, holds the exit side end of the image forming unit and the second lens, and seals the second space included between the light exit surface of the image forming unit and the light incident surface of the second lens, and at least one of the first space and the second space is filled with a cooling medium, the cooling medium absorbs heat from the image forming unit, convects inside the at least one space, and transfers heat to the heating surface of the first heating surface and the second heating surface exposed to the at least one space, and the outer peripheral surface of the image forming unit is exposed inside the outer casing.

[0262] According to such a structure, the image forming unit, which is a heat source, is held by a first holder that seals a first space on the light incident side of the image forming unit and a second holder that seals a second space on the light emitting side of the image forming unit. The cooling medium filled in at least one of the first and second spaces absorbs the heat of the image forming unit and convects, and is stirred in the at least one space to dissipate the absorbed heat to the heating surface. Thus, the heat of the image forming unit can be dissipated to at least one of the first and second holders, thereby cooling the image forming unit. Therefore, the cooling efficiency of the image forming unit, which is a heat source, can be improved.

[0263] Furthermore, since the light incident surface and the light emitting surface of the image forming unit are sealed by the first holder and the second holder, it is possible to suppress dust from being attached to the image forming unit, thereby suppressing the shadow of dust from being reflected on the projected image.

[0264] Furthermore, the outer peripheral surface of the image forming unit is exposed inside the outer casing, so the wiring of the image forming unit can extend to the space inside the outer casing, and therefore, there is no need to seal the wiring. Therefore, there is no need for a sealing structure for the wiring, so that the brightness of the light source can be increased while maintaining the size of the projector, thereby increasing the brightness of the projected image.

[0265] [Note 2]

[0266] In the projector described in Note 1, the image forming unit comprises: a liquid crystal panel; a color filter, which is arranged on the light emitting side of the liquid crystal panel, and the image light emitted from the liquid crystal panel passes through the color filter; an output side polarizer, which is arranged on the light emitting side of the color filter, and the image light passing through the color filter passes through the output side polarizer, and the cooling medium is filled in the second space.

[0267] According to such a structure, full-color image light can be formed by one liquid crystal panel. In addition, part of the heat generated by the liquid crystal panel can be transferred to the cooling medium in the second space via the color filter and the output-side polarizing plate. Therefore, the liquid crystal panel can be cooled.

[0268] [Note 3]

[0269] In the projector described in Note 1 or Note 2, the projector has an incident-side polarizer, the incident-side polarizer is arranged on the light incident side of the liquid crystal panel, the light incident on the liquid crystal panel passes through the incident-side polarizer, the first holder holds the incident-side polarizer between the first lens and the liquid crystal panel, the incident-side polarizer and the liquid crystal panel are separated from each other in a manner that a part of the first space exists, and the first space is filled with the cooling medium.

[0270] Here, when the light emitted from the light source and incident on the incident-side polarizing plate is not one type of linearly polarized light, the incident-side polarizing plate also becomes a heat source that generates heat due to the incidence of light.

[0271] On the other hand, the cooling medium filled in the first space can cool the incident-side polarizing plate in addition to the liquid crystal panel, so that the incident-side polarizing plate and the liquid crystal panel can be cooled efficiently.

[0272] [Note 4]

[0273] In the projector according to Supplementary Note 3, the light incident surface of the incident-side polarizing plate is exposed in the first space.

[0274] According to such a configuration, since the light incident surface and the light emitting surface of the incident-side polarizing plate are exposed in the first space, the incident-side polarizing plate can be efficiently cooled by the cooling medium.

[0275] [Note 5]

[0276] In the projector according to any one of Supplementary Notes 1 to 4, the first holder accommodates the light source in a sealed state.

[0277] According to such a configuration, the cooling medium filled in the first space can also flow through the light source. Therefore, the light source can be cooled by the cooling medium.

[0278] [Note 6]

[0279] In the projector described in any one of Supplementary Notes 1 to 4, the second holder is connected to the incident side end of the projection lens to seal from the emission side end of the image forming unit to the incident side end of the projection lens.

[0280] According to such a configuration, when the second space in the second holder is filled with the cooling medium, the optical components arranged on the optical path from the emission side end of the image forming unit to the incident side end of the projection lens can be cooled by the cooling medium.

[0281] Furthermore, the second holder seals the area from the emission side end of the image forming unit to the incident side end of the projection lens, so the second space is a space from the emission side end of the image forming unit to the incident side end of the projection lens. Therefore, the second space is a relatively large space, so the heat capacity of the second space can be increased. Therefore, the temperature of the cooling medium in the second space can be suppressed from rising sharply due to the heat of the heat source, and the optical element in the second space can be effectively cooled.

[0282] [Note 7]

[0283] In the projector described in Note 6, the projector comprises: an optical path changing component, which changes the traveling direction of light emitted from the second lens between the second lens and the incident side end of the projection lens; and a circulating fan, which is arranged between the inner surface of the second retainer and the optical path changing component to circulate the cooling medium, and the optical path changing component and the circulating fan are arranged inside the second retainer.

[0284] According to this structure, a circulation fan for circulating the cooling medium can be arranged in the dead zone between the inner surface of the second holder and the optical path changing member. Therefore, in addition to improving the cooling performance of the image forming unit, even if the circulation fan is arranged, the enlargement of the projector can be suppressed.

[0285] [Note 8]

[0286] In the projector according to any one of Supplementary Notes 1 to 7, at least one of the first holder and the second holder includes a heat dissipation fin exposed to the internal space of the outer casing.

[0287] According to such a structure, the heat of the heat source disposed inside the at least one holder can be dissipated to the outside of the at least one holder through the heat sink, thereby improving the cooling efficiency of the heat source disposed inside the at least one holder.

[0288] [Note 9]

[0289] In the projector described in any one of Supplementary Notes 1 to 8, the projector includes: a base member on which the light source is arranged; and a heat dissipation member to which heat of the light source is transferred via the base member.

[0290] According to such a configuration, the heat of the light source transferred via the base member can be dissipated by the heat dissipation member. Therefore, the light source can be cooled.

[0291] [Note 10]

[0292] In the projector described in Appendix 9, the projector includes a first fan arranged inside the outer casing, and the outer casing has: an inlet port, which introduces gas outside the outer casing into the interior of the outer casing; and an outlet port, which discharges gas flowing inside the outer casing to the outside of the outer casing, and the heat dissipation component is arranged at a position closer to the outlet port than the inlet port, and the first fan causes the gas introduced into the interior of the outer casing to flow to the outlet port via the heat dissipation component.

[0293] According to this structure, the gas introduced into the outer casing can be circulated in the heat dissipation member by the first fan, so that the heat dissipation of the light source by the heat dissipation member can be promoted, and the cooling efficiency of the light source can be improved.

[0294] [Note 11]

[0295] In the projector described in Supplementary Note 10, the projector includes a power source, and the power source is disposed on the air intake side of the first fan and supplies power to at least one of the light source and the image forming unit.

[0296] According to this structure, the gas introduced into the outer casing from the introduction port can be circulated at the power source by the first fan. Therefore, the power source and the light source can be cooled by driving the first fan.

[0297] [Note 12]

[0298] In the projector described in Note 10 or Note 11, the projector has a second fan, and the second fan is arranged inside the outer shell at a position closer to the inlet than the exhaust port, so that the gas introduced into the interior of the outer shell flows through the first retainer and the second retainer.

[0299] According to this structure, the gas introduced into the outer casing can be circulated in the first holder and the second holder by the second fan, thereby improving the heat dissipation efficiency of the heat source arranged in each holder and improving the cooling efficiency of the heat source.

[0300] [Note 13]

[0301] In the projector according to any one of Supplementary Notes 1 to 12, the cooling medium is any of helium gas, hydrogen gas, and hydrofluoroether-based liquid.

[0302] By using the cooling medium having high thermal conductivity or the cooling medium having high specific heat as listed above as the cooling medium, the cooling performance of the image forming unit can be improved.

Claims

1. A projector, characterized in that: It has: a light source emitting white light; a first lens for converging the white light emitted from the light source; an image forming unit configured to emit image light obtained by modulating the white light incident from the first lens; a second lens for converging the image light emitted from the image forming unit; a projection lens that projects the image light incident from the second lens; an outer casing that accommodates the light source, the first lens, the image forming unit, the second lens, and the projection lens; a first holder having a first heat receiving surface therein, holding the first lens and the incident side end of the image forming unit, and sealing a first space between the light emitting surface of the first lens and the light incident surface of the image forming unit; and a second holder having a second heat receiving surface therein, holding the light exiting end of the image forming unit and the second lens, and sealing a second space between the light exiting surface of the image forming unit and the light incident surface of the second lens, A cooling medium is filled in at least one of the first space and the second space, and the cooling medium absorbs heat from the image forming unit, convects in the at least one space, and transfers heat to the first heat receiving surface and the second heat receiving surface that are exposed to the at least one space. An outer peripheral surface of the image forming unit is exposed inside the outer casing.

2. The projector according to claim 1, characterized in that The image forming unit has: 1 LCD panel; a color filter disposed on a light-emitting side of the liquid crystal panel, through which the image light emitted from the liquid crystal panel passes; an output-side polarizing plate disposed on the light output side of the color filter, through which the image light having passed through the color filter passes, The second space is filled with the cooling medium.

3. The projector according to claim 2, characterized in that: The projector includes an incident-side polarizing plate, the incident-side polarizing plate being arranged on the light incident side of the liquid crystal panel, and the light incident on the liquid crystal panel passes through the incident-side polarizing plate. The first holder holds the incident-side polarizing plate between the first lens and the liquid crystal panel. The incident-side polarizing plate and the liquid crystal panel are separated from each other in a manner that a portion of the first space exists. The first space is filled with the cooling medium.

4. The projector according to claim 3, characterized in that: The light incident surface of the incident-side polarizing plate is exposed in the first space.

5. The projector according to claim 1, characterized in that: The image forming unit has: 1 LCD panel; and an incident-side polarizing plate, which is disposed on the light incident side of the liquid crystal panel, and the light incident on the liquid crystal panel passes through the incident-side polarizing plate, The first holder holds the incident-side polarizing plate between the first lens and the liquid crystal panel. The incident-side polarizing plate and the liquid crystal panel are separated from each other in a manner that a portion of the first space exists. The first space is filled with the cooling medium.

6. The projector according to any one of claims 1 to 5, characterized in that: The first holder accommodates the light source in a sealed state.

7. The projector according to any one of claims 1 to 5, characterized in that: The second holder is connected to the incident side end of the projection lens, and seals the area from the emission side end of the image forming unit to the incident side end of the projection lens.

8. The projector according to claim 7, characterized in that: The projector has: an optical path changing member that changes the traveling direction of light emitted from the second lens between the second lens and an incident-side end portion of the projection lens; and a circulation fan, which is arranged between the inner surface of the second holder and the optical path changing member, and circulates the cooling medium; The optical path changing member and the circulation fan are arranged inside the second holder.

9. The projector according to any one of claims 1 to 5, characterized in that: At least one of the first holder and the second holder has a heat dissipation fin exposed to the internal space of the outer case.

10. The projector according to any one of claims 1 to 5, characterized in that: The projector has: a base member configured with the light source; and A heat dissipation component to which the heat of the light source is transferred via the base component.

11. The projector according to claim 10, characterized in that: The projector includes a first fan disposed inside the outer casing. The outer casing has: an inlet for introducing gas outside the outer casing into the interior of the outer casing; as well as an exhaust port for exhausting the gas flowing inside the outer casing to the outside of the outer casing, The heat dissipation member is arranged at a position closer to the discharge port than to the inlet port. The first fan allows the gas introduced into the interior of the outer casing to flow toward the exhaust port via the heat dissipating member.

12. The projector according to claim 11, characterized in that: The projector includes a power source, which is disposed on the air intake side of the first fan and supplies power to at least one of the light source and the image forming unit.

13. The projector according to claim 11, characterized in that: The projector includes a second fan disposed inside the outer casing at a position closer to the introduction port than to the discharge port, and causes the gas introduced into the inner part of the outer casing to flow through the first holder and the second holder.

14. The projector according to any one of claims 1 to 5, characterized in that: The cooling medium is any one of helium, hydrogen and hydrofluoroether liquid.

Images