CN221765922U

CN221765922U - Projector with a light source for projecting light

Info

Publication number: CN221765922U
Application number: CN202322625058.2U
Authority: CN
Inventors: 门谷典和; 宫冈靖晃
Original assignee: Seiko Epson Corp
Current assignee: Seiko Epson Corp
Priority date: 2022-10-05
Filing date: 2023-09-26
Publication date: 2024-09-24
Anticipated expiration: 2033-09-26
Also published as: JP2024054503A

Abstract

And a projector. The cooling efficiency of the heat source can be improved. The projector has: a light source that emits white light; a 1 st lens that condenses white light emitted from a light source; 1 light modulation element which emits image light obtained by modulating white light incident from the 1 st lens; a 2 nd lens which condenses the image light emitted from the light modulation element; a projection lens which projects the image light emitted from the 2 nd lens; an exterior case accommodating the light source, the 1 st lens, the light modulation element, the 2 nd lens, and the projection lens; a holder having a heating surface on an inner surface thereof, holding the 1 st lens, the light modulation element, and the 2 nd lens, and sealing a 1 st space between a light exit surface of the 1 st lens and a light entrance surface of the 2 nd lens, wherein the light modulation element is interposed between the light exit surface and the light entrance surface; and a cooling medium filled in the 1 st space, absorbing heat of the light modulation element, and convection-transmitting heat to the heating surface in the 1 st space.

Description

Projector with a light source for projecting light

Technical Field

The present utility model relates to a projector.

Background

Conventionally, a projector including a light source, a light modulation device that modulates light emitted from the light source, and a projection lens that projects the light modulated by the light modulation device is known (for example, refer to patent document 1).

The projector described in patent document 1 includes a cooling device that cools the light source and the light modulation element. The cooling device includes a light source cooling unit provided in the light source, a holding frame for holding the light modulation device, a heat exchanger disposed in a sealed housing for housing the light modulation device, a radiator, and a pump for circulating a liquid refrigerant. The cooling device includes a plurality of fans disposed in a sealed housing, and a gas such as helium is enclosed in the sealed housing.

The light source is cooled by a liquid refrigerant flowing through the light source cooling unit. The light modulation device is cooled by a liquid refrigerant flowing through the holding frame, and is also cooled by a gas which is circulated in the sealed frame by a plurality of fans and cooled by a heat sink.

In addition, a rear projection type projector having a simplified structure is known (for example, refer to patent document 2).

In the rear projector described in patent document 2, light emitted from a light source enters a liquid crystal panel through a 1 st transmissive fresnel lens. The light modulated by the liquid crystal panel is projected onto a screen mounted on the housing by a projection lens through a 2 nd transmissive fresnel lens. The 1 st transmission Fresnel lens, the liquid crystal panel, the 2 nd transmission Fresnel lens and the projection lens are arranged in the frame body.

Patent document 1: japanese patent laid-open No. 2020-79950

Patent document 2: japanese patent laid-open No. 7-319066

In recent years, a small projector is also required to have high brightness of a projected image. 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 tends to be high, and the light source tends to be deteriorated. Further, if a liquid crystal panel is used as the light modulation element, the amount of light entering the liquid crystal panel increases, and the temperature of the liquid crystal panel increases, which may affect the operation of the liquid crystal.

In contrast, it is considered to increase the amount of light incident on the liquid crystal panel from the light source, to increase the brightness of the projected image, and to cool the light source and the liquid crystal panel with a liquid refrigerant using the cooling device described in patent document 1, to suppress degradation of the light source due to temperature, and to stably operate the liquid crystal panel. However, if such a cooling device is used, there is a problem that the projector is easily enlarged even if the structure of the optical system is simplified as in the projector described in patent document 2.

Therefore, a structure capable of improving the cooling efficiency of the heat source even in a small projector is desired.

Disclosure of utility model

A projector according to an embodiment of the present utility model includes: a light source that emits white light; a 1 st lens that condenses the white light emitted from the light source; 1 light modulation element which emits image light obtained by modulating the white light incident from the 1 st lens; a 2 nd lens that condenses the image light emitted from the light modulation element; a projection lens that projects the image light emitted from the 2 nd lens; an exterior case accommodating the light source, the 1 st lens, the light modulation element, the 2 nd lens, and the projection lens; a holder having a heating surface on an inner surface thereof, the holder holding the 1 st lens, the light modulation element, and the 2 nd lens, and sealing a 1 st space between a light exit surface of the 1 st lens and a light entrance surface of the 2 nd lens, the light exit surface and the light entrance surface being spaced apart by the light modulation element; and a cooling medium filled in the 1 st space, absorbing heat of the light modulation element, and convecting inside the 1 st space to transfer heat to the heating surface.

Drawings

Fig. 1 is a schematic diagram showing the structure of a projector in embodiment 1.

Fig. 2 is a perspective view showing the retainer in embodiment 1.

Fig. 3 is a perspective view showing the retainer in embodiment 1.

Fig. 4 is a cross-sectional view showing the retainer in embodiment 1.

Fig. 5 is a cross-sectional view showing the retainer in embodiment 1.

Fig. 6 is a schematic diagram showing the structure of the projector in embodiment 2.

Fig. 7 is a schematic diagram showing the structure of the projector in embodiment 3.

Fig. 8 is a schematic diagram showing the structure of a projector in a modification of embodiment 3.

Description of the reference numerals

1A, 1B, 1C, 1D projector; 2A, 2D outer shells; 2A1 front side; 2A2 back side; 2A3 left side; 2A4 right side; 2A5 inlet; 2A6 outlet; 3 an image projection unit; 31 light source; a 32 base member; 33 reflectors; 34 lens 1; 342 light exit face; 35 a light modulating element; 351 an incident side polarizer; 3511 light incident surface; 3512 light exit surface; 352 a liquid crystal panel; 3521 light incident surface; 3522 light exit face; 353 a transmissive liquid crystal element; 3531 light incident surface; 3532 light exit face; 354 color filters; 355 an exit side polarizer; 3551 light incident surface; 3552 light exit face; 36 nd lens; 361 light incidence surface; 362 a light exit face; 37 light path changing means; 38 a projection lens; 381 light incident surface; 4A, 4B, 4C holders; 4A1 st opening portion; 4A2 nd opening; 4A3 rd opening; 4A4 valve 1; 4A5 valve 2; 4A6 heating surface; 4A7 radiating surfaces; 4A8 cooling fins; 4A81 fins; 4A9, 4a91, 4a92 holding parts; 5, a power supply; 6 a heat conduction member; a heat transport component 61; 62 heat dissipation members; 7, a cooling fan; 71 1 st cooling fan (holder outer fan); 72 nd cooling fan (holder outer fan); 8, circulating fans; HS heat source.

Detailed Description

[ Embodiment 1]

Embodiment 1 of the present utility model will be described below with reference to the drawings.

[ Outline Structure of projector ]

Fig. 1 is a schematic diagram showing the structure of a projector 1A of the present embodiment.

The projector 1A of the present embodiment projects image light corresponding to image information. As shown in fig. 1, projector 1A includes an outer case 2A, an image projection unit 3, a holder 4A, a power supply 5, a heat conductive member 6, and a cooling fan 7. Although not shown, the projector 1A includes a control unit that controls the operation of the projector 1A.

[ Structure of outer housing ]

The outer case 2A is a substantially rectangular parallelepiped case constituting the outer case of the projector 1A. The outer case 2A is coupled to the projection lens 38 of the image projection unit 3, and houses the image projection unit 3, the holder 4A, the power supply 5, the heat conductive member 6, and the cooling fan 7.

The exterior case 2A has a front surface 2A1, a rear surface 2A2, a left side surface 2A3, and a right side surface 2A4, and also has a top surface and a bottom surface, which are not shown.

In the front face 2A1, a part of the projection lens 38 constituting the image projection unit 3 is exposed.

The rear surface 2A2 is a surface of the outer case 2A opposite to the front surface 2A 1.

The left side surface 2A3 is a surface intersecting the front surface 2A1 and the rear surface 2A2, respectively.

The right side surface 2A4 is a surface of the outer case 2A opposite to the left side surface 2A 3.

The outer case 2A further has an inlet 2A5 and an outlet 2A6.

The inlet 2A5 is provided on the left side surface 2A3. The inlet 2A5 introduces the gas outside the outer case 2A into the outer case 2A as cooling gas.

The discharge port 2A6 is provided on the right side surface 2A4. That is, the discharge port 2A6 is provided in the outer case 2A on the side surface opposite to the side surface on which the introduction port 2A5 is provided. The exhaust port 2A6 exhausts the cooling gas inside the outer case 2A to the outside of the outer case 2A.

The cooling gas introduced from the inlet 2A5 into the exterior case 2A and discharged from the outlet 2A6 to the outside of the exterior case 2A is circulated by driving a cooling fan 7 described later.

[ Structure of image projection Unit ]

The image projection unit 3 is housed in the outer case 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, a1 st lens 34, a light modulation element 35, a 2 nd lens 36, an optical path changing member 37, and a projection lens 38.

[ Structure of light Source and base Member ]

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 1 light emitting element, and the light emitting element is configured by a solid-state light source such as an LED (LIGHT EMITTING Diode). The light source 31 is one of the heat sources HS of the projector 1A, and is disposed on the base member 32. The light source 31 is disposed closer to the right side surface 2A4 than the projection lens 38, and emits white light in a direction from the right side surface 2A4 toward the left side surface 2 A3. The reflector 33, the 1 st lens 34, the light modulation element 35, the 2 nd lens 36, and the light path changing member 37 are disposed on the light path of the white light emitted from the light source 31.

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 conductive member 6 described later, and heat transferred from the light source 31 to the base member 32 is transferred to the heat conductive member 6.

[ Structure of reflector ]

The reflector 33 makes the traveling direction of the light emitted from the light source 31 uniform. The reflector 33 and the light source 31 are coupled so as not to leak light. The reflector 33 is similar to the 1 st lens 34.

The reflector 33 may be 1 of a quadrangular frustum-shaped reflector, an elliptical reflector having an elliptical surface of revolution, and a parabolic reflector having a parabolic surface of revolution. The reflector 33 may be a hollow reflector having a space formed therein, or may be a solid reflector having a translucent material filled therein.

[ Structure of 1 st lens ]

The 1 st lens 34 condenses light emitted from the light source 31 and incident via the reflector 33. The 1 st lens 34 is constituted by a fresnel lens, and expands the diameter of incident light effectively at a short distance. That is, the 1 st lens 34 is a 1 st fresnel lens.

As will be described later in detail, the 1 st lens 34 is fixed to a position closing the 1 st opening 4A1 of the holder 4A.

The light exit surface 342 of the 1 st lens 34 is fixed to the holder 4A, and is exposed inside the holder 4A. The cooling medium filled in the holder 4A can be in contact with the light exit surface 342.

[ Structure of light modulation element ]

The light modulation element 35 modulates the white light incident from the 1 st lens 34 according to an image signal input from a control unit not shown, and emits color image light. That is, the light modulation element 35 modulates the white light emitted from the light source 31 according to the image signal, and emits the image light of full color. In the present embodiment, the projector 1A includes 1 light modulation element 35. In other words, the image projection unit 3 includes 1 light modulation element 35.

The light modulation element 35 includes 1 incident-side polarizer 351, 1 image forming unit 352, and 1 exit-side polarizer 355.

[ Structure of incident side polarizing plate ]

The incident-side polarizing plate 351 is disposed so as to be separated from the 1 st lens 34 to the light-emitting side of the 1 st lens 34 and from the liquid crystal panel 352 to the light-incident side of the liquid crystal panel 352. That is, the incident-side polarizing plate 351 and the liquid crystal panel 352 are separated from each other so as to have a part of the 1 st space SP1 in the holder 4A described later.

The incident-side polarizing plate 351 has a light incident surface 3511 opposite to the 1 st lens 34 and a light emitting surface 3512 opposite to the light incident surface 3511. The light incident surface 3511 and the light emitting surface 3512 are exposed inside a holder 4A described later. That is, the cooling medium described later in the holder 4A can be in contact with the light incident surface 3511 and the light emitting surface 3512, respectively.

The incident-side polarizing plate 351 transmits the 1 st linearly polarized light out of the light incident from the 1 st lens 34, and absorbs the 2 nd linearly polarized light. One of the 1 st linearly polarized light and the 2 nd linearly polarized light is p polarized light, and the other linearly polarized light is s polarized light.

In the present 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 absorbing the 2 nd linearly polarized light generates heat by incidence of the white light emitted from the light source 31. Thus, the incident-side polarizing plate 351 is one of the heat sources HS of the projector 1A.

As described in detail later, the incident-side polarizing plate 351 is held by a holding portion 4A9 provided in a holder 4A described later.

[ Structure of liquid Crystal Panel ]

The liquid crystal panel 352 modulates light incident from the incident-side polarizing plate 351 according to an image signal. The liquid crystal panel 352 has a light incident surface 3521 and a light emitting surface 3522.

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.

The light emitting surface 3522 is a surface of the liquid crystal panel 352 opposite to the light incident surface 3521. The light emitting surface 3522 emits light modulated by the liquid crystal panel 352.

Such a liquid crystal panel 352 has 1 transmissive liquid crystal element 353 and 1 color filter 354, and is composed of a combination of the transmissive liquid crystal element 353 disposed on the light incident side and the color filter 354 disposed on the light emitting side.

[ Structure of transmissive liquid Crystal element ]

The transmissive liquid crystal element 353 modulates light incident from the incident-side polarizing plate 351, and emits modulated light along the traveling direction of the light incident from the incident-side polarizing plate 351. That is, the liquid crystal panel 352 is a transmissive liquid crystal panel. The transmissive liquid crystal element 353 has a light incident surface 3531 and a light emitting surface 3532.

The light incident surface 3531 is a surface facing the incident-side polarizing plate 351 and into which light is incident from the incident-side polarizing plate 351. The light incident surface 3531 constitutes a light incident surface 3521 of the liquid crystal panel 352.

The light emitting surface 3532 is a surface opposite to the light incident surface 3531, and emits light transmitted through the transmissive liquid crystal element 353.

The transmissive liquid crystal element 353 generates heat by incidence of light and supply of electric power. In addition, the liquid crystal included in the transmissive liquid crystal element 353 is degraded by heat. Therefore, the transmissive liquid crystal element 353 is one of the heat sources HS in the projector 1A that needs cooling. That is, the liquid crystal panel 352 is the heat source HS in the projector 1A.

[ Structure of color Filter ]

The color filter 354 is disposed on the light exit surface 3532. The color filter 354 has a plurality of color filter elements arranged in accordance with 1 pixel constituted by the transmissive liquid crystal element 353, which is not shown in detail. 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 provided in accordance with the sub-pixels of the corresponding pixels. The red filter is a filter that transmits red light, the green filter is a filter that transmits green light, and the blue filter is a filter that transmits blue light.

However, the color filter 354 is not limited to such a color filter, and may be a monochrome color filter provided corresponding to each pixel.

[ Structure of exit-side polarizer ]

The exit-side polarizing plate 355 is fixed to the liquid crystal panel 352 in contact with the light exit surface 3522 of the liquid crystal panel 352. That is, the light incident surface 3551 of the emission-side polarizing plate 355 contacts the light emitting surface of the color filter 354. The exit-side polarizing plate 355 is disposed so as to be separated from the 2 nd lens 36 toward the light incident side of the 2 nd lens 36.

The light exit surface 3552 of the exit-side polarizing plate 355 is exposed inside the holder 4A, and the cooling medium in the holder 4A can contact the light exit surface 3552.

When the polarization transmission axis of the output-side polarizer 355 and the polarization transmission axis of the input-side polarizer 351 are orthogonal to each other, the output-side polarizer 355 transmits light modulated by the liquid crystal panel 352, and absorbs light not modulated by the liquid crystal panel 352. When the polarization transmission axis of the exit-side polarizer 355 and the polarization transmission axis of the entrance-side polarizer 351 are parallel to each other, the exit-side polarizer 355 absorbs light modulated by the liquid crystal panel 352, and transmits light not modulated by the liquid crystal panel 352. Therefore, the emission-side polarizing plate 355 is also one of the heat sources HS of the projector 1A.

The liquid crystal panel 352 to which such an emission-side polarizing plate 355 is fixed is held by a holding portion 4A9 provided inside a holder 4A described later. The cooling medium in the holder 4A can be in contact with the light incident surface 3521 of the liquid crystal panel 352 and the light emitting surface 3552 of the emitting-side polarizing plate 355, respectively.

[ Structure of the 2 nd lens ]

The 2 nd lens 36 is disposed so as to be separated from the emission-side polarizer 355 to the light emission side of the emission-side polarizer 355. The 2 nd lens 36 condenses the image light emitted from the emission-side polarizing plate 355, and makes it incident on the optical path changing member 37. The 2 nd lens 36 is constituted by a fresnel lens. That is, the 2 nd lens 36 is a 2 nd fresnel lens.

As will be described in detail later, the 2 nd lens 36 is fixed at a position where the 2 nd opening 4A2 and the 2 nd opening 4A2 of the holder 4A are closed. That is, the 2 nd lens 36 is fixed to the holder 4A.

The light incident surface 361 of the 2 nd lens 36 is exposed to the inside of the holder 4A, and the light emitting surface 362 of the 2 nd lens 36 is exposed to the outside of the holder 4A. The cooling medium in the holder 4A can be in contact with the light incident surface 361. On the other hand, the light emitting surface 362 of the 2 nd lens 36 is exposed outside the holder 4A, i.e., inside the exterior case 2A.

[ Structure of optical path changing Member ]

The optical path changing member 37 is disposed between the 2 nd lens 36 and the projection lens 38 on the optical path of the image light. That is, the optical path changing member 37 is constituted by a reflecting mirror disposed between the light modulation element 35 and the projection lens 38 on the optical path of the image light.

The optical path changing member 37 has a light incident surface 371 on which the image light is incident from the 2 nd lens 36 and a surface 372 on the opposite side of the light incident surface 371. The light incident surface 371 is a reflecting surface in the present embodiment.

The optical path changing member 37 changes the traveling direction of the image light emitted from the 2 nd lens 36 and incident on the light incident surface 371 by 90 ° and guides the image light to the projection lens 38.

[ Structure of projection lens ]

The projection lens 38 projects the image light incident from the optical path changing member 37. Although not shown, the projection lens 38 may be configured as a lens group including a plurality of lenses and a barrel accommodating the plurality of lenses. The light-emitting side portion of the projection lens 38 is coupled to the outer case 2A, and the other portion of the projection lens 38 is housed in the outer case 2A with the light-emitting side portion exposed outside the outer case 2A.

[ Structure of retainer ]

The holder 4A holds the 1 st lens 34, the light modulation element 35, and the 2 nd lens 36. The holder 4A seals the 1 st space SP1 between the light exit surface 342 of the 1 st lens 34 and the light entrance surface 361 of the 2 nd lens 36, with the light modulation element 35 interposed between the light exit surface 342 and the light entrance surface 361. Specifically, the holder 4A holds the exit-side end of the 1 st lens 34 and the entrance-side end of the 2 nd lens 36, and holds the entrance-side polarizing plate 351 and the liquid crystal panel 352 to which the exit-side polarizing plate 355 is fixed inside the holder 4A. That is, the holder 4A houses the incident-side polarizing plate 351, the liquid crystal panel 352, and the exit-side polarizing plate 355.

Fig. 2 and 3 are perspective views showing the retainer 4A. In detail, fig. 2 is a perspective view showing the holder 4A as viewed from the light incident side, and fig. 3 is a perspective view showing the holder 4A as viewed from the light emitting side. Fig. 4 and 5 are cross-sectional views showing the retainer 4A.

As shown in fig. 2, the holder 4A is formed in a rectangular frame shape when viewed from the light incident side. As shown in fig. 2 to 5, the retainer 4A includes A1 st opening 4A1, A2 nd opening 4A2, A3 rd opening 4A3, A1 st valve 4A4, A2 nd valve 4A5, a heating surface 4A6, a heat radiation surface 4A7, and a fin 4A8. The 1 st space SP1 in the holder 4A is filled with a cooling medium. That is, the projector 1A includes a cooling medium filled in the 1 st space SP 1. As the cooling medium, any of gaseous refrigerants such as helium and hydrogen and liquid refrigerants such as hydrofluoroethers may be used.

In the following description, three directions orthogonal to each other are defined as +x direction, +y direction, and +z direction. Here, the +z direction is the traveling direction of the white light emitted from the light source 31. The holder 4A is viewed along the +z direction, and the left direction when the +y direction is the upward direction is the +x direction.

Although not shown, the direction opposite to the +x direction is referred to as the-X direction, the direction opposite to the +y direction is referred to as the-Y direction, and the direction opposite to the +z direction is referred to as the-Z direction. The axis along the +x direction is referred to as the X axis, the axis along the +y direction is referred to as the Y axis, and the axis along the +z direction is referred to as the Z axis.

For example, the +z direction portion of the holder 4A is a light exit side portion of the holder 4A, and the-Z direction portion of the holder 4A is a light entrance side portion of the holder 4A.

As shown in fig. 4, the 1 st opening 4A1 and the 2 nd opening 4A2 communicate the 1 st space SP1 outside and inside the holder 4A, respectively.

As shown in fig. 2 and 4, the 1 st opening 4A1 is provided at a portion of the holder 4A on the light incident side, and opens in the-Z direction. The 1 st opening 4A1 is closed by the 1 st lens 34. Specifically, as shown in fig. 4, when the 1 st lens 34 is fixed to the holder 4A so that the light exit surface 342 of the 1 st lens 34 contacts with the end portion of the holder 4A on the light incident side, the 1 st opening 4A1 is closed by the 1 st lens 34. That is, the 1 st lens 34 exposes the light incident surface 341 of the 1 st lens 34 to the space inside the outer case 2A, and closes the 1 st opening 4A1 in a state where the 1 st space SP1 is closed.

The 1 st opening 4A1 is an opening through which white light emitted from the light source 31 passes. Specifically, the 1 st opening 4A1 is an opening for allowing white light emitted from the 1 st lens 34 exposed to the outside of the holder 4A to enter the light modulation element 35 held in the holder 4A.

As shown in fig. 3 and 4, the 2 nd opening 4A2 is provided at a portion of the holder 4A on the light emission side, and is opened in the +z direction.

The 2 nd opening 4A2 is closed by the 2 nd lens 36. Specifically, as shown in fig. 4, when the 2 nd lens 36 is fixed to the holder 4A so that the light incident surface 361 of the 2 nd lens 36 contacts with the end portion on the light emitting side of the holder 4A, the 2 nd opening 4A2 is closed by the 2 nd lens 36. That is, the 2 nd lens 36 exposes the light exit surface 362 of the 2 nd lens 36 to the space inside the outer case 2A, and closes the 2 nd opening 4A2 in a state where the 1 st space SP1 is closed.

The 2 nd opening 4A2 is an opening through which the image light formed by the light modulation element 35 passes. Specifically, the 2 nd opening 4A2 is an opening for allowing the image light emitted from the light modulation element 35 held in the holder 4A to enter the 2 nd lens 36, and the light emitting surface 362 of the 2 nd lens 36 is exposed to the outside of the holder 4A.

As shown in fig. 2 and 3, the 3 rd opening 4A3 is provided at a part of the outer peripheral surface of the holder 4A. Specifically, the 3 rd opening 4A3 is provided in a portion facing the +y direction on the outer peripheral surface of the holder 4A. The outer peripheral surface of the holder 4A is a surface along the circumferential direction centering on the optical axis of the holder 4A.

The 3 rd opening 4A3 is an opening through which the flexible printed board FPC connected to the transmissive liquid crystal element 353 shown in fig. 1 is inserted along the Y axis. Although not shown, a sealing material PK such as a gasket is disposed between the inner edge of the 3 rd opening 4A3 and the flexible printed circuit board FPC. This suppresses leakage of the cooling medium in the 1 st space SP1 to the outside of the holder 4A through the 3 rd opening 4 A3.

The 1 st valve 4A4 and the 2 nd valve 4A5 are used for injecting and discharging the cooling medium into and from the 1 st space SP 1. The 1 st valve 4A4 and the 2 nd valve 4A5 communicate the inside of the retainer 4A with the outside.

As shown in fig. 2, the 1 st valve 4A4 is provided on an outer surface of the retainer 4A facing in the-X direction. Specifically, the 1 st valve 4A4 is provided at a +y direction portion of the outer surface of the retainer 4A facing in the-X direction.

As shown in fig. 3, the 2 nd valve 4A5 is provided on the outer surface of the retainer 4A facing in the +x direction. Specifically, the 2 nd valve 4A5 is provided at a portion of the outer surface of the retainer 4A facing in the +x direction in the-Y direction.

The injection of the cooling medium into the 1 st space SP1 can be performed by the following steps using, for example, the 1 st valve 4A4 and the 2 nd valve 4 A5. In the following steps, the retainer 4A is disposed such that the 1 st valve 4A4 is located on the upper side and the 2 nd valve 4A5 is located on the lower side.

When helium gas having a lighter specific gravity than air is used as the cooling medium, the 2 nd valve 4A5 is opened, and helium gas is injected from the 1 st valve 4A4 into the holder 4A. Thereby, the air in the holder 4A is discharged from the 2 nd valve 4A5, and helium gas is filled into the holder 4A. The same applies to the case of using hydrogen gas lighter in specific gravity than air as the cooling medium.

When a liquid refrigerant of hydrofluoroethers having a specific gravity heavier than that of air is used as the cooling medium, the 1 st valve 4A4 is opened, and liquid cooling is injected from the 2 nd valve 4A5 into the holder 4A. Thereby, the air in the retainer 4A is discharged from the 1 st valve 4A4, and the liquid refrigerant is filled into the retainer 4A.

In this way, when the cooling medium is injected into the holder 4A, one of the 1 st valve 4A4 and the 2 nd valve 4A5 is used as the discharge valve, and the other valve is used as the injection valve. Therefore, it is preferable to dispose one valve on the upper side with respect to the other valve. If one valve is disposed above the other valve, for example, the 1 st valve 4A4 and the 2 nd valve 4A5 may be disposed diagonally to each other when the holder 4A is viewed from the light incident side, or may be disposed on the outer surface in the +x direction or the-X direction.

The retainer 4A may be provided with only one of the 1 st valve 4A4 and the 2 nd valve 4A 5. In this case, for example, the gas or liquid in the holder 4A may be sucked from one valve, the inside of the holder 4A may be brought into a substantially vacuum state, and then the cooling medium may be injected into the holder 4A. This also allows the cooling medium to be filled into the holder 4A.

As shown in fig. 4 and 5, the heating surface 4A6 is provided inside the holder 4A. The heating surface 4A6 constitutes at least a part of the inner surface of the holder 4A, and is exposed inside the holder 4A. In the present embodiment, the heating surface 4A6 is substantially the entire inner surface of the holder 4A. The heating surface 4A6 is heated from the cooling medium of the 1 st space SP 1.

The heat radiation surface 4A7 is provided outside the holder 4A, and radiates heat received by the heating surface 4A 6. The heat radiation surface 4A7 constitutes at least a part of the outer surface of the holder 4A, and is exposed to the outside of the holder 4A. In the present embodiment, the heat radiation surface 4A7 is substantially the entire outer surface of the holder 4A. In addition, when the heat radiation surface 4A7 is not substantially the entire outer surface of the holder 4A, the heat radiation surface 4A7 is provided on the outer surface on the opposite side of the heating surface 4A6 constituting the inner surface of the holder 4A, for example. That is, the heating surface 4A6 and the radiating surface 4A7 are in a forward-reverse relationship.

The heat radiation fins 4A8 are provided on the heat radiation surface 4A7 which is an outer surface on the opposite side to the heating surface 4A6, and radiate heat transmitted to the heat radiation surface 4A7. Specifically, the heat radiating fins 4A8 are provided on the heat radiating surface 4A7 facing in the-X direction and the heat radiating surface 4A7 facing in the +x direction, respectively, of the heat radiating surfaces 4A7.

The fin 4A8 is composed of at least 1 fin 4a81, and in the present embodiment, a plurality of fins 4a81 protruding from the heat radiation surface 4A7 are arranged along the Y axis. That is, the holder 4A includes a plurality of fins 4A81 arranged on the heat radiation surface 4A7 on the opposite side of the heating surface 4A 6.

In addition, a heat dissipation paint may be applied to the heat dissipation fins 4 A8.

As shown in fig. 4 and 5, the holder 4A further has a pair of holding portions 4A9 provided inside the holder 4A.

One holding portion 4A91 of the pair of holding portions 4A9 is provided at an end portion in the-X direction inside the holder 4A. The holding portion 4a91 holds the end portions of the incident-side polarizing plate 351, the liquid crystal panel 352, and the exit-side polarizing plate 355 in the-X direction.

The other holding portion 4A92 of the pair of holding portions 4A9 is provided at an end portion in the +x direction inside the holder 4A. The holding portion 4a92 holds the +x-direction end portions of each of the incident-side polarizing plate 351, the liquid crystal panel 352, and the exit-side polarizing plate 355.

In this way, the pair of holding portions 4A9 hold the ends in the ±x directions of the incident-side polarizer 351, the liquid crystal panel 352, and the exit-side polarizer 355, respectively. In other words, in the ±y directions with respect to the incident-side polarizer 351, the liquid crystal panel 352, and the exit-side polarizer 355, as shown in fig. 5, a gap GP is provided in which the cooling medium in the holder 4A can flow in the ±z directions. Therefore, the cooling medium filled in the holder 4A can flow between the 1 st lens 34 and the incident-side polarizer 351, between the incident-side polarizer 351 and the liquid crystal panel 352, and between the exit-side polarizer 355 and the 2 nd lens 36.

Further, since the pair of holding portions 4A9 are in contact with the incident-side polarizing plate 351, the liquid crystal panel 352, and the emission-side polarizing plate 355, which are the heat sources HS, heat of these heat sources HS is also transferred to the pair of holding portions 4A9.

[ Convection of Cooling Medium ]

In the 1 st space SP1, the light emitting surface 342 of the 1 st lens 34 and the light incident surface 361 of the 2 nd lens 36 are exposed, and the incident-side polarizing plate 351, the liquid crystal panel 352, and the emission-side polarizing plate 355 are housed therein. As described above, the incident-side polarizing plate 351, the liquid crystal panel 352, and the exit-side polarizing plate 355 are heat sources HS, respectively.

As shown in fig. 5, for example, the cooling medium filled in the 1 st space SP1 absorbs heat from the light incident surface 3511 of the incident-side polarizing plate 351. Similarly, the cooling medium absorbs heat from the light emitting surface 3512 of the incident-side polarizer 351, the light emitting surface 3521 of the liquid crystal panel 352, and the light emitting surface 3551 of the exit-side polarizer 355. When the +y direction is the upward direction and the X axis is the horizontal axis, the cooling medium having a temperature rise moves in the +y direction as indicated by an open arrow A1 in fig. 5, contacts the heating surface 4A6 arranged in the +y direction, and transfers heat to the heating surface 4 A6.

A part of the cooling medium in contact with the heating surface 4A6 in the +y direction flows in the-X direction along the heating surface 4A6, and reaches the heating surface 4A6 in the-X direction as indicated by an open arrow A2. At this time, the temperature of the cooling medium is further lowered by the heat transfer of the cooling medium to the heating surface 4A6 in the-X direction, and the cooling medium moves along the heating surface 4A6 in the-X direction in the-Y direction as the extending direction. After that, the cooling medium moves in the +x direction along the heating surface 4A6 in the-Y direction. Thereby, the temperature of the cooling medium is further reduced.

The other cooling medium among the cooling mediums in contact with the heating surface 4A6 in the +y direction flows along the heating surface 4A6 in the +x direction, and reaches the heating surface 4A6 in the +x direction as indicated by an open arrow A3. At this time, the temperature of the cooling medium is further lowered by the heat transfer of the cooling medium to the heating surface 4A6 in the +x direction, and the cooling medium moves along the heating surface 4A6 in the +x direction in the-Y direction as the extending direction. After that, the cooling medium moves in the +x direction along the heating surface 4A6 in the-Y direction. Thereby, the temperature of the cooling medium is further reduced.

The cooling medium that moves to the center of the heating surface 4A6 in the-Y direction moves in the +y direction while being heated from the heat source HS.

In this way, the cooling medium in the 1 st space SP1 repeats heat absorption from the heat source HS and heat dissipation to the heating surface 4A6, and natural convection occurs due to the temperature difference of the cooling medium in the 1 st space SP1, whereby stirring is performed in the 1 st space SP 1.

On the other hand, the heat of the cooling medium received by the heating surface 4A6 is transferred to the heat radiation surface 4A7, and is radiated to the outside of the holder 4A through the heat radiation surface 4A7 and the heat radiation fins 4 A8.

Further, by driving a cooling fan 7 described later, a cooling gas introduced from the outside of the outer case 2A flows through the holder 4A. This promotes the heat dissipation of the cooling medium by the heat dissipation surface 4A7 and the heat dissipation fins 4A8, and further promotes the heat dissipation of the heat source HS.

[ Structure of Power supply ]

As shown in fig. 1, the power supply 5 is disposed inside the outer case 2A. Specifically, the power supply 5 is disposed in the light reflection direction of the light path changing member 37 with respect to the holder 4A housing the light modulation element 35.

The power supply 5 converts the power supplied from the outside of the projector 1A, and supplies the converted power to each structure of the projector 1A. For example, the power supply 5 supplies power to the light source 31, the liquid crystal panel 352, and a control unit not shown.

Such a power supply 5 is one of the heat sources HS of the projector 1A.

[ Structure of Heat conductive Member ]

The heat conductive member 6 transfers heat of the light source 31 to the cooling gas flowing in the outer case 2A. The heat conductive member 6 includes a heat transporting member 61 and a heat radiating member 62.

The heat transfer member 61 transfers heat transferred to the light source 31 of the base member 32 to the heat radiation 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 radiation member 62. The heat transport member 61 may be constituted by a heat pipe, for example.

The heat radiation member 62 radiates heat of the light source 31 transmitted by the heat transmission member 61. Specifically, the heat radiation member 62 transfers the heat of the transported light source 31 to the cooling gas flowing in the outer case 2A. The heat dissipation member 62 may be constituted by, for example, a heat sink.

In the present embodiment, the heat radiating member 62 is disposed in the vicinity of the outlet 2A6 in the outer case 2A, and is disposed at a position where the cooling air is circulated by the cooling fan 7. Specifically, the heat radiating member 62 is disposed between the discharge port 2A6 and the 2 nd cooling fan 72.

[ Structure of Cooling Fan ]

The cooling fan 7 introduces cooling gas into the outer case 2A through the inlet 2A5, circulates the introduced cooling gas in the outer case 2A, and discharges the cooling gas from the discharge port 2A6 to the outside of the outer case 2A. The cooling fan 7 includes a 1 st cooling fan 71 and a 2 nd cooling fan 72.

The 1 st cooling fan 71 is one of the holder outer fans. The 1 st cooling fan 71 is disposed closer to the inlet 2A5 than the 2 nd cooling fan 72. The 1 st cooling fan 71 introduces the air outside the outer case 2A as cooling air into the outer case 2A through the inlet 2A5, and sends the cooling air to the holder 4A. That is, the 1 st cooling fan 71 circulates the cooling gas through the plurality of fins 4a81 constituting the heat sink 4 A8. Thereby, the cooling gas flows to the fins 4 A8. A part of the cooling gas sent by the 1 st cooling fan 71 also flows through at least one of the light source 31 and the base member 32.

The 2 nd cooling fan 72 is one of the holder outer fans. The 2 nd cooling fan 72 is disposed closer to the discharge port 2A6 than the 1 st cooling fan 71. The 2 nd cooling fan 72 sucks the cooling gas in the outer case 2A, circulates the cooling gas through the power supply 5 and the heat radiating member 62, and then discharges the cooling gas to the outside of the outer case 2A through the discharge port 2A 6.

[ Cooling with Cooling gas ]

As shown in fig. 1, when the 1 st cooling fan 71 is driven, the cooling gas introduced into the exterior case 2A from the inlet 2A5 flows through the light source 31, the base member 32, and the holder 4A.

The light source 31 or the base member 32 radiates heat of the light source 31 to the cooling gas.

The holder 4A radiates heat received by the heating surface 4A6 to the cooling gas through the radiating surface 4A7 and the radiating fins 4A 8.

Thereby, the heat radiation surface 4A7 and the heat radiation fins 4A8 are cooled in addition to the light source 31, and the heat source HS in the holder 4A is cooled via the cooling medium.

When the 2 nd cooling fan 72 is driven, the cooling gas flows through the power supply 5 disposed on the intake side of the 2 nd cooling fan 72 while the 2 nd cooling fan 72 sucks the cooling gas in the outer case 2A. Thereby, the power supply 5 is cooled. Some of the cooling gas flowing through the power supply 5 is the cooling gas flowing through the holder 4A.

The 2 nd cooling fan 72 sends the sucked cooling gas to the heat radiating member 62. Thereby, the heat radiation member 62 transmits heat of the light source 31 transmitted through the base member 32 and the heat transport member 61 to the flowing cooling gas. The cooling gas, which is circulated through the heat radiating member 62 and is transferred to the heat of the light source 31, is discharged from the discharge port 2A6 to the outside of the outer case 2A.

[ Effect of embodiment 1 ]

The projector 1A of the present embodiment described above has the following effects.

The projector 1A includes a light source 31, a1 st lens 34, a light modulation element 35, a 2 nd lens 36, a projection lens 38, an outer case 2A, a holder 4A, and a cooling medium.

The light source 31 emits white light. The 1 st lens 34 condenses white light emitted from the light source 31. 1 light modulation element 35 is provided in the projector 1A. The light modulation element 35 emits image light obtained by modulating white light incident from the 1 st lens 34. The 2 nd lens 36 condenses the image light emitted from the light modulation element 35. The projection lens 38 projects the image light emitted from the 2 nd lens 36. The outer case 2A houses the light source 31, the 1 st lens 34, the light modulation element 35, the 2 nd lens 36, and the projection lens 38. The housing case 2A houses the projection lenses 38 is not limited to housing all of the projection lenses 38.

The holder 4A has a heating surface 4A6 on the inner surface. The holder 4A holds the 1 st lens 34, the light modulation element 35, and the 2 nd lens 36. The holder 4A seals the 1 st space SP1 between the light exit surface 342 of the 1 st lens 34 and the light entrance surface 361 of the 2 nd lens 36, with the light modulation element 35 interposed between the light exit surface 342 and the light entrance surface 361.

The cooling medium is filled in the 1 st space SP1. The cooling medium absorbs heat of the light modulation element 35, convects inside the 1 st space SP1, and transfers the heat to the heating surface 4 A6.

With this configuration, the light modulation element 35 as the heat source HS is held by the holder 4A closing the 1 st space SP 1. The cooling medium filled in the 1 st space SP1 absorbs heat from the light modulator 35, flows in the 1 st space SP1, and is stirred in the 1 st space SP 1. The cooling medium radiates the absorbed heat to the heating surface 4A6 of the holder 4A. Thereby, the light modulation element 35 can be cooled.

Therefore, compared with a configuration in which the light modulation element 35 is cooled by circulating the liquid refrigerant, the number of components can be suppressed, and the light modulation element 35 can be cooled by a relatively simple configuration. Therefore, even if the brightness of the light source 31 is increased, the light modulation element 35 can be cooled, and therefore, the projector 1A can be miniaturized and the brightness of the projected image of the projector 1A can be increased.

In the projector 1A, the light modulation element 35 includes an incident-side polarizer 351, a liquid crystal panel 352, and an exit-side polarizer 355.

The incident-side polarizing plate 351 is disposed on the light incident side of the liquid crystal panel 352. The light emitted from the 1 st lens 34 enters the incident-side polarizing plate 351.

The emission-side polarizing plate 355 is disposed on the light emission side of the liquid crystal panel 352. The exit-side polarizing plate 355 emits light emitted from the liquid crystal panel 352 toward the 2 nd lens 36.

The incident-side polarizing plate 351 and the liquid crystal panel 352 are separated from each other so that a part of the 1 st space SP1 exists.

Here, when the white light emitted from the light source 31 is not 1 type of linearly polarized light, the incident-side polarizing plate 351 disposed on the light incident side of the liquid crystal panel 352 also serves as a heat source HS that generates heat due to the incident light.

In contrast, the cooling medium flows between the incident-side polarizing plate 351 and the liquid crystal panel 352, and therefore, the 2 heat sources HS of the incident-side polarizing plate 351 and the liquid crystal panel 352 can be efficiently cooled.

In projector 1A, light incident surface 3511 of incident-side polarizing plate 351 is exposed to 1 st space SP1.

With this configuration, the light incident surface 3511 and the light emitting surface 3512 of the incident-side polarizing plate 351 are exposed to the 1 st space SP1. As a result, the incident-side polarizing plate 351 can be cooled efficiently by the cooling medium flowing through the 1 st space SP1.

In projector 1A, emission-side polarizer 355 is fixed in contact with light emission surface 3522 of liquid crystal panel 352. The light-emitting surface 3552 of the light-emitting-side polarizing plate 355 is exposed to the 1 st space SP1.

The heat generation amount of the exit-side polarizer 355 is smaller than the heat generation amount of the entrance-side polarizer 351 and the heat generation amount of the liquid crystal panel 352. Therefore, the light-emitting-side polarizer 355 can be cooled by heat exchange between the light-emitting surface 3552 and the cooling medium.

The light-emitting-side polarizing plate 355 is fixed to the light-emitting surface 3522 of the liquid crystal panel 352 held by the holder 4A. This can suppress an increase in size of the holder 4A, compared with a case where the holder 4A holds the liquid crystal panel 352 and the emission-side polarizing plate 355 separately.

In the projector 1A, the liquid crystal panel 352 includes a transmissive liquid crystal element 353 and a color filter 354.

The transmissive liquid crystal element 353 emits modulated light in the traveling direction of the incident light.

The color filter 354 is disposed on the light emitting surface 3532 of the transmissive liquid crystal element 353.

According to such a configuration, a color image corresponding to the image signal can be formed by 1 liquid crystal panel 352.

In the projector 1A, the holder 4A has A1 st opening 4A1 and A2 nd opening 4A2.

The 1 st opening 4A1 is an opening through which white light emitted from the light source 31 passes.

The 2 nd opening 4A2 is an opening through which the image light formed by the light modulation element 35 passes.

The 1 st lens 34 exposes the light incident surface 341 of the 1 st lens 34 to the space inside the outer case 2A, and closes the 1 st opening 4A1 in a state where the 1 st space SP1 is closed.

The 2 nd lens 36 exposes the light exit surface 362 of the 2 nd lens 36 to the space inside the outer case 2A, and closes the 2 nd opening 4A2 in a state where the 1 st space SP1 is closed.

With this configuration, the 1 st lens 34 closes the 1 st opening 4A1 in a state where the light incident surface 341 of the 1 st lens 34 is exposed to the space inside the exterior case 2A, and the 2 nd lens 36 closes the 2 nd opening 4A2 in a state where the light emitting surface 362 of the 2 nd lens 36 is exposed to the space inside the exterior case 2A. Thus, the 1 st space SP1 can be sealed by closing the openings 4A1 and 4A2 without providing a separate member for closing the openings 4A1 and 4A2. Therefore, the size of the holder 4A can be suppressed from increasing, and the projector 1A can be suppressed from increasing in size.

In the projector 1A, the holder 4A includes a plurality of fins 4A81 arranged on the heat radiation surface 4A7 on the opposite side of the heating surface 4A 6. The radiating surface 4A7 constitutes an outer surface of the holder 4A.

According to this configuration, the plurality of fins 4a81 can improve the heat radiation performance of the heat received by the heating surface 4 A6. This can maintain the temperature difference between the heat source HS and the heating surface 4A6, and therefore, stirring in the 1 st space SP1 caused by convection of the cooling medium can be promoted.

The projector 1A includes a 1 st cooling fan 71, and the 1 st cooling fan 71 is disposed in the outer case 2A to circulate cooling gas through the plurality of fins. The 1 st cooling fan 71 is one of the holder outer fans.

With this configuration, the heat radiation performance of the plurality of fins 4A81 provided in the holder 4A with respect to the heat source HS can be improved.

In the projector 1A, at least one of the 1 st lens 34 and the 2 nd lens 36 is a fresnel lens. In the present embodiment, the 1 st lens 34 and the 2 nd lens 36 are fresnel lenses, respectively.

With such a configuration, the optical path length from the light source 31 to the projection lens 38 can be shortened. Therefore, the size of the holder 4A can be reduced, and the projector 1A can be further reduced.

In the projector 1A, the cooling medium is any of helium, hydrogen, and hydrofluoroether type liquids.

By using the above-listed cooling medium having high thermal conductivity or the cooling medium having high specific heat as the cooling medium, the cooling performance of the light modulation element 35 can be improved.

[ Embodiment 2]

Next, embodiment 2 of the present utility model will be described.

The projector of the present embodiment has the same configuration as the projector 1A of embodiment 1, but the configuration of the holder and the number of optical components housed in the holder are different. In the following description, the same or substantially the same portions as those already described are denoted by the same reference numerals, and description thereof is omitted.

[ Outline Structure of projector ]

Fig. 6 is a schematic diagram showing the structure of the projector 1B of the present embodiment. In fig. 6, only a part of the plurality of fins 4a81 is marked for easy observation.

The projector 1B of the present embodiment has the same structure and function as the projector 1A of embodiment 1 except that the retainer 4B shown in fig. 6 is provided instead of the retainer 4A of embodiment 1. That is, the projector 1B includes the outer case 2A, the image projection unit 3, the holder 4B, the power supply 5, the heat conductive member 6, and the cooling fan 7.

[ Structure of retainer ]

The holder 4B holds the base member 32, the reflector 33, the 1 st lens 34, the light modulation element 35, and the 2 nd lens 36, and seals the 1 st space SP2 between the light exit surface of the base member 32 and the light entrance surface 361 of the 2 nd lens 36, with the light source 31, the reflector 33, the 1 st lens 34, and the light modulation element 35 interposed between the light exit surface of the base member 32 and the light entrance surface 361. That is, the holder 4B seals at least the 1 st space SP2 between the light exit surface 342 of the 1 st lens 34 and the light entrance surface 361 of the 2 nd lens 36, with the light modulation element 35 interposed between the light exit surface 342 and the light entrance surface 361. The 1 st space SP2 is filled with the cooling medium.

The holder 4B has, like the holder 4A, the 1 st opening 4A1, the 2 nd opening 4A2, the heating surface 4A6, the heat radiation surface 4A7, the heat radiation fins 4A8, and the holding portion 4A9. Although not shown, the retainer 4B has A3 rd opening 4A3, a1 st valve 4A4, and a2 nd valve 4A5, similar to the retainer 4A.

The 1 st opening 4A1 in the holder 4B is provided at a portion of the holder 4B on the light incident side, and opens in the-Z direction. The 1 st opening 4A1 is closed in a state where the 1 st space SP2 is closed by the base member 32. Specifically, when the base member 32 is fixed to the holder 4B such that the light incident side end of the holder 4B contacts the light emitting side surface 321 of the base member 32, the 1 st opening 4A1 is closed by the base member 32. Further, a light source 31 provided in the base member 32 is disposed inside the 1 st opening 4 A1. That is, the light source 31 is disposed in the 1 st space SP 2.

The 2 nd opening 4A2 in the holder 4B emits image light formed by the light modulation element 35. The 2 nd opening 4A2 is closed by the 2 nd lens 36 in the same manner as the 2 nd opening 4A2 in the holder 4A.

Like the heating surface 4A6 of the holder 4A, the heating surface 4A6 of the holder 4B forms at least a part of the inner surface of the holder 4B, and is exposed to the inside of the holder 4B, thereby receiving heat from the cooling medium in the 1 st space SP 2. A part of the heating surface 4A6 is disposed on an inner surface facing the light source 31 in the holder 4B. Specifically, the inner surface of the 1 st opening 4A1 in which the light source 31 is disposed is the heating surface 4A6. In the present embodiment, the heating surface 4A6 is also substantially the entire inner surface of the holder 4B.

The heat radiation surface 4A7 of the holder 4B constitutes at least a part of the outer surface of the holder 4B, and is exposed to the outside of the holder 4B to radiate heat received by the heat receiving surface 4A6. In the present embodiment, the heat radiation surface 4A7 is substantially the entire outer surface of the holder 4B. As in the case of the holder 4A of embodiment 1, when the heat radiation surface 4A7 is not substantially the entire outer surface of the holder 4B, the heat radiation surface 4A7 is provided on the outer surface on the opposite side of the heating surface 4A6 constituting the inner surface of the holder 4B, for example.

The heat radiation fins 4A8 of the holder 4B are provided on the heat radiation surface 4A7, and radiate heat transmitted to the heat radiation surface 4 A7.

The pair of holding portions 4A9 in the holder 4B holds the reflector 33, the 1 st lens 34, the incident-side polarizing plate 351, the liquid crystal panel 352, and the exit-side polarizing plate 355. Although not shown in detail, the holding portion 4A9 also holds the end portions of the reflector 33, the 1 st lens 34, the incident-side polarizing plate 351, the liquid crystal panel 352, and the exit-side polarizing plate 355, which are opposite to each other, when viewed from the light incident side, in the holder 4B.

For example, one holding portion 4a91 holds the end portions of the reflector 33, the 1 st lens 34, the incident-side polarizing plate 351, the liquid crystal panel 352, and the exit-side polarizing plate 355 in the-X direction. The other holding portion 4a92 holds the +x-direction end portions of the reflector 33, the 1 st lens 34, the incident-side polarizing plate 351, the liquid crystal panel 352, and the exit-side polarizing plate 355.

In this way, the holder 4B accommodates the light source 31, the reflector 33, the 1 st lens 34, the incident-side polarizing plate 351, the liquid crystal panel 352, and the emission-side polarizing plate 355 therein, and supports the base member 32 and the 2 nd lens 36 so that a part of the base member 32 and the light incident surface 361 of the 2 nd lens 36 are exposed inside the holder 4B.

Further, a reflective layer or the like may be provided on the inner surface of the holder 4B, so that a part of the holder 4B functions as the reflector 33.

[ Cooling of the Heat Source by the Cooling Medium in the holder ]

The cooling medium filled in the 1 st space SP2 in the holder 4B contacts the light source 31, the incident-side polarizing plate 351, the liquid crystal panel 352, and the exit-side polarizing plate 355, which are the heat sources HS disposed in the 1 st space SP2, and absorbs heat from these heat sources HS.

The cooling medium that absorbs heat from the heat source HS flows through the 1 st space SP2 and contacts the heating surface 4A6, and transfers heat to the heating surface 4A6, similarly to the cooling medium in the holder 4A of embodiment 1. Thereby, the cooling medium is cooled, and the cooling medium flows through the 1 st space SP2 to absorb heat from the heat source HS again.

The heat of the heat source HS transferred from the cooling medium to the heating surface 4A6 is radiated to the outside of the holder 4B through the radiating surface 4A7 and the radiating fins 4 A8. Since the cooling gas outside the outer case 2A flows through the 1 st cooling fan 71 to the holder 4B, the heat dissipation of the heat dissipation surface 4A7 and the heat dissipation fins 4A8 is promoted, and the cooling efficiency of the cooling medium and the heat source HS is improved.

[ Effect of embodiment 2 ]

The projector 1B of the present embodiment described above has the following effects in addition to the same effects as the projector 1A of embodiment 1.

The projector 1B includes a base member 32 that supports the light source 31.

The holder 4B has A1 st opening 4A1 closed in a state where the 1 st space SP2 is closed by the base member 32 and A2 nd opening 4A2 from which the image light is emitted.

The 2 nd lens 36 exposes the light exit surface 362 of the 2 nd lens 36 to the space inside the outer case 2A, and closes the 2 nd opening 4A2 in a state where the 1 st space SP2 is closed.

The light source 31 is accommodated in the 1 st space SP2.

According to such a configuration, the cooling medium filled in the 1 st space SP2 can exchange heat with the light source 31. Thereby, the light modulation element 35 and the light source 31 can be cooled by the cooling medium.

Further, since the 1 st opening 4A1 is closed by the base member 32 supporting the light source 31 and the 2 nd opening 4A2 is closed by the 2 nd lens 36, it is not necessary to provide a separate member for closing the openings 4A1 and 4 A2. Therefore, the size of the holder 4B and the size of the projector 1B can be suppressed.

In the projector 1B, a part of the heating surface 4A6 is disposed on an inner surface facing the light source 31 in the holder 4B.

According to this configuration, the heat of the cooling medium received from the light source 31 can be heated at a part of the heating surface 4 A6. Therefore, the cooling medium can be promoted to absorb heat from the light source 31.

Further, by providing the heat radiation fins 4A8 at positions on the outer surface of the holder 4B corresponding to the heating surfaces 4A6, the heat received by the heating surfaces 4A6 can be quickly radiated to the outside of the holder 4B. This can promote the heating of the heating surface 4A6 from the cooling medium, and therefore, can further promote the heat absorption of the cooling medium from the light source 31. Therefore, the cooling efficiency of the light source 31 can be further improved.

[ Embodiment 3]

Next, embodiment 3 of the present utility model will be described.

The projector of the present embodiment has the same configuration as the projector 1A of embodiment 1 and the projector 1B of embodiment 2, but includes a fan disposed in the holder in addition to the configuration of the holder and the number of optical components housed in the holder. In the following description, the same or substantially the same portions as those already described are denoted by the same reference numerals, and description thereof is omitted.

[ Outline Structure of projector ]

Fig. 7 is a schematic diagram showing the structure of the projector 1C of the present embodiment. In fig. 7, only a part of the plurality of fins 4a81 is marked for easy observation.

The projector 1C of the present embodiment includes a retainer 4C shown in fig. 7 in place of the retainer 4A of embodiment 1, and includes a circulation fan 8 as a retainer external fan, and has the same structure and function as those of the projector 1A of embodiment 1. That is, the projector 1C includes the outer case 2A, the image projection unit 3, the holder 4C, the power supply 5, the heat conductive member 6, the cooling fan 7, and the circulation fan 8.

[ Structure of retainer ]

The holder 4C holds the 1 st lens 34, the light modulation element 35, the 2 nd lens 36, the optical path changing member 37, and the projection lens 38, and seals the 1 st space SP3 between the light exit surface 342 of the 1 st lens 34 and the light entrance surface 381 of the projection lens 38, with the light modulation element 35, the 2 nd lens 36, and the optical path changing member 37 interposed between the light exit surface 342 and the light entrance surface 381. That is, the holder 4C seals at least the 1 st space SP3 between the light exit surface 342 of the 1 st lens 34 and the light entrance surface 361 of the 2 nd lens 36, with the light modulation element 35 interposed between the light exit surface 342 and the light entrance surface 361. The 1 st space SP3 is filled with the cooling medium.

The retainer 4C has, like the retainer 4A, the 1 st opening 4A1, the 2 nd opening 4A2, the heating surface 4A6, the heat radiation surface 4A7, the heat radiation fins 4A8, and the pair of retaining portions 4A9. Although not shown, the retainer 4C has A3 rd opening 4A3, a1 st valve 4A4, and a2 nd valve 4A5, similar to the retainer 4A.

The 1 st opening 4A1 of the holder 4C is closed by the 1 st lens 34 in the same manner as the 1 st opening 4A1 of the holder 4A of embodiment 1.

The 1 st opening 4A1 is an opening through which white light emitted from the light source 31 passes. That is, the 1 st opening 4A1 is an opening for allowing light emitted from the 1 st lens 34 exposed to the outside of the holder 4C to enter the light modulation element 35 held in the holder 4C.

The 2 nd opening 4A2 of the holder 4C is provided at a portion of the holder 4C on the light emission side, and is opened in the +x direction. When the projection lens 38 and the holder 4C are combined so that the end of the projection lens 38 on the light incidence side contacts the peripheral edge of the 2 nd opening 4A2, the 2 nd opening 4A2 is closed by the projection lens 38. In other words, the projection lens 38 closes the 2 nd opening 4A2 in a state of closing the 1 st space SP 3.

The 2 nd opening 4A2 is an opening through which the image light formed by the light modulation element 35 passes. That is, the 2 nd opening 4A2 is an opening for making the image light emitted from the light modulation element 35 held in the holder 4C incident on the projection lens 38 exposed to the outside of the holder 4C.

Like the heating surface 4A6 of the holder 4A, the heating surface 4A6 of the holder 4C forms at least a part of the inner surface of the holder 4C, and is exposed to heat from the cooling medium in the 1 st space SP 3. In the present embodiment, the heating surface 4A6 is substantially the entire inner surface of the holder 4C.

The heat radiation surface 4A7 of the holder 4C constitutes at least a part of the outer surface of the holder 4C, and is exposed to the outside of the holder 4C to radiate heat received by the heat receiving surface 4 A6. In the present embodiment, the heat radiation surface 4A7 is substantially the entire outer surface of the holder 4C. As in the case of the holders 4A, 4B of embodiment 1 and embodiment 2, when the heat radiation surface 4A7 is not substantially the entire outer surface of the holder 4C, the heat radiation surface 4A7 is provided on the outer surface on the opposite side of the heating surface 4A6 constituting the inner surface of the holder 4C, for example.

The heat radiation fins 4A8 of the holder 4C are provided on the heat radiation surface 4A7, and radiate heat transmitted to the heat radiation surface 4 A7.

In the example of fig. 7, the heat radiation fins 4A8 are provided substantially in the entire heat radiation surface 4 A7. However, the heat sink 4A8 is not limited to this, and may be provided only in a part of the heat radiating surface 4 A7.

In fig. 7, a plurality of fins 4a81 constituting the heat radiating fin 4A8 are arranged in a plurality along the flow direction of the cooling gas introduced into the outer case 2A from the inlet 2A5, and each fin 4a81 protrudes from the heat radiating surface 4A7 in a direction intersecting the flow direction of the cooling gas. In order to facilitate observation of the plurality of fins 4a81, it is actually preferable that each fin 4a81 extends along the flow direction of the cooling gas.

The pair of holding portions 4A9 in the holder 4C are provided inside the holder 4C, and hold the incident-side polarizing plate 351, the liquid crystal panel 352, the emission-side polarizing plate 355, the 2 nd lens 36, and the optical path changing member 37. Although not shown in detail, in the holder 4C, the holding portion 4A9 holds the end portions of the incident-side polarizing plate 351, the liquid crystal panel 352, the exit-side polarizing plate 355, the 2 nd lens 36, and the optical path changing member 37, which are opposite to each other when viewed from the light incident side.

For example, one holding portion 4a91 holds the end portions of each of the incident-side polarizer 351, the liquid crystal panel 352, the exit-side polarizer 355, the 2 nd lens 36, and the optical path changing member 37 in the-X direction. The other holding portion 4a92 holds the +x-direction end portions of each of the incident-side polarizing plate 351, the liquid crystal panel 352, the exit-side polarizing plate 355, the 2 nd lens 36, and the optical path changing member 37.

Therefore, although not shown, a gap in which the cooling medium can flow in the ±z direction is provided in the ±y direction with respect to the incident-side polarizer 351, the liquid crystal panel 352, the exit-side polarizer 355, the 2 nd lens 36, and the optical path changing member 37 when viewed from the light incident side.

[ Structure of circulation Fan ]

The circulation fan 8 corresponds to an in-holder fan. The circulation fan 8 is disposed in the 1 st space SP3 in the holder 4C, and circulates the cooling medium in the holder 4C to assist convection of the cooling medium. Specifically, the circulation fan 8 is disposed between the surface 372 of the light path changing member 37 on the opposite side to the light incident surface 371 and the inner surface of the holder 4C facing the surface 372.

Such a circulation fan 8 may be constituted by a centrifugal force fan, for example.

The circulation fan 8 sends the cooling medium sucked in the sealed 1 st space SP3 in the-Z direction toward the incident-side polarizing plate 351, the liquid crystal panel 352, and the exit-side polarizing plate 355, which are the heat sources HS. That is, the circulation fan 8 sends the cooling gas to the light modulator 35. Further, the wiring for driving the circulation fan 8 is disposed so as to overlap with the flexible printed board FPC connected to the transmissive liquid crystal element 353, and can be led out of the holder 4C.

The cooling medium to be sent out flows in the +x direction between the 1 st lens 34 and the incident-side polarizer 351, between the incident-side polarizer 351 and the liquid crystal panel 352, and between the exit-side polarizer 355 and the 2 nd lens 36. Thereby, heat is transferred from the incident-side polarizing plate 351, the liquid crystal panel 352, and the exit-side polarizing plate 355 to the cooling medium, and these heat sources HS are cooled.

The cooling medium after absorbing heat contacts the heating surface 4A6 in the +x direction in the holder 4C, and flows along the heating surface 4A6 in the +z direction. The cooling medium flowing in the +z direction contacts the heating surface 4A6 in the +z direction, and transfers heat to the heating surface 4 A6. Thereby, the cooling medium is cooled.

The cooled cooling medium is sucked by the circulation fan 8 and sent out again toward the incident-side polarizer 351, the liquid crystal panel 352, and the exit-side polarizer 355.

In this way, the circulation fan 8 promotes convection of the cooling medium in the 1 st space SP3, and further promotes heat absorption from the heat source HS and heat dissipation from the cooling medium to the heating surface 4 A6.

The 1 st cooling fan 71, not shown in fig. 7, sends out cooling gas to circulate the cooling gas through the heat radiation surface 4A7 and the heat radiation fins 4A8 of the holder 4C. The 2 nd cooling fan 72 sucks the cooling gas to circulate the cooling gas through the heat dissipation surface 4A7 and the heat dissipation fins 4A8 of the holder 4C. This effectively dissipates heat received by the heat radiation surface 4A7 and the heat radiation fins 4A8 from the heat source HS in the holder 4C.

[ Effect of embodiment 3 ]

The projector 1C of the present embodiment described above has the following effects in addition to the same effects as the projector 1A of embodiment 1.

In the projector 1C, the holder 4C has A1 st opening 4A1 through which light emitted from the light source 31 passes and A2 nd opening 4A2 through which image light passes.

The 1 st lens 34 closes the 1 st opening 4A1 in a state of closing the 1 st space SP 3.

The projection lens 38 closes the 2 nd opening 4A2 in a state of closing the 1 st space SP 3.

With this structure, it is not necessary to provide a separate member for closing the openings 4A1 and 4 A2. Therefore, the size of the holder 4C and the size of the projector 1C can be suppressed.

The projector 1C includes a circulation fan 8, and the circulation fan 8 is disposed in the holder 4C to circulate the cooling medium through the light modulation element 35. The circulation fan 8 corresponds to an in-holder fan.

According to this configuration, the circulation fan 8 circulates the cooling gas through the light modulator 35, and the cooling efficiency of the light modulator 35 can be improved.

[ Modification of embodiment 3 ]

In the projector 1C described above, the discharge port 2A6 of the outer case 2A is provided on the right side surface 2A4 intersecting the front surface 2A1 exposed by the projection lens 38. However, the present invention is not limited to this, and a discharge port for discharging the cooling gas flowing through the outer case to the outside of the outer case may be provided on other surfaces of the outer case.

Fig. 8 is a schematic diagram showing a projector 1D including an exterior case 2D instead of the exterior case 2A, which is a modification of the projector 1C.

For example, the projector 1D shown in fig. 8 has the same configuration and functions as the projector 1C described above, except that it includes an exterior case 2D instead of the exterior case 2A. The outer case 2D has the same structure and function as the outer case 2A, except that it has a discharge port 2D6 instead of the discharge port 2 A6.

The discharge port 2D6 is provided on the front surface 2A1. That is, the discharge port 2D6 is provided on a side surface of the outer case 2D intersecting the left side surface 2A3 on which the introduction port 2A5 is provided. The exhaust port 2D6 exhausts the cooling gas inside the outer case 2D to the outside of the outer case 2D.

In the case of using such an outer case 2D, the 2 nd cooling fan 72 is disposed such that the heat radiating member 62 and the exhaust port 2D6 are positioned in the direction of the cooling gas of the 2 nd cooling fan 72. Thereby, the cooling gas flowing along the holder 4C and the power supply 5 and flowing to the heat radiating member 62 can be discharged from the discharge port 2D6 to the outside of the outer case 2D.

Since the discharge port 2A6 is not provided in the right side surface 2A4, the right side surface 2A4 can be used as a bottom surface provided on the mounting surface SF such as a floor. At this time, the cooling medium having heat for cooling the optical modulator 35 as the heat source HS can be easily circulated to the heating surface 4A6 side opposite to the heat radiation surface 4A7 provided with the heat radiation fins 4A8 in the holder 4C. Therefore, the heat of the light modulation element 35 received by the cooling medium can be easily radiated through the heat radiation surface 4A7 and the heat radiation fins 4A8 via the heating surface 4 A6. The leg portion may be disposed on the right side surface 2A4 serving as the bottom surface.

Such an exterior case 2D can be used for the projector 1A according to embodiment 1 and the projector 1B according to embodiment 2.

The projector 1D described above has the following effects in addition to the same effects as the projector 1C described above.

In the projector 1D, the outer case 2A has an inlet 2A5. The inlet 2A5 is provided on the left side surface 2A3 which is an outer surface opposite to the right side surface 2A4 when the right side surface 2A4 is opposite to the mounting surface, which is an outer surface on the light source 31 side.

A part of the heating surface 4A6 is provided on the inner surface of the opposite side to the mounting surface among the inner surfaces of the holder 4C. That is, a part of the heating surface 4A6 is provided on the inner surface in the +y direction in the holder 4C.

According to this configuration, the cooling medium that absorbs heat from the light modulator 35 as the heat source HS flows to the opposite side of the mounting surface SF in the 1 st space SP3 in the holder. Therefore, by providing a part of the heating surface 4A6 on the inner surface on the opposite side to the mounting surface SF among the inner surfaces of the holder 4C, heat can be effectively received from the cooling medium with heat. Therefore, the cooling medium can promote heat absorption from the heat source HS such as the light modulator 35.

Further, by providing the heat radiating fins 4A8 on the heat radiating surface 4A7 on the opposite side of the heating surface 4A6 in the +y direction, the heat received by the heating surface 4A6 can be quickly radiated to the outside of the holder 4C. Therefore, the heating surface 4A6 can be promoted to receive heat from the cooling medium, so that heat absorption of the cooling medium from the light modulation element 35 can be further promoted, and the cooling efficiency of the light modulation element 35 can be further improved.

[ Modification of embodiment ]

The present utility model is not limited to the above embodiments, and modifications and improvements within a range that can achieve the object of the present utility model are included in the present utility model.

In each of the above embodiments, the image projection unit 3 includes the light source 31, the base member 32, the reflector 33, the 1 st lens 34, the light modulation element 35, the 2 nd lens 36, the optical path changing member 37, and the projection lens 38. However, the image projection unit 3 is not limited to this, and may not include some of the optical components described above, or may include other optical components. For example, at least 1 of the base member 32, the reflector 33, and the optical path changing member 37 may not be provided.

In the above embodiments, substantially all of the inner surfaces of the holders 4A, 4B, 4C are the heating surfaces 4A6, and substantially all of the outer surfaces of the holders 4A, 4B, 4C are the heat radiation surfaces 4A7. However, the heating surface 4A6 that can be heated from the cooling medium is not limited to this, and may be a part of the inner surfaces of the holders 4A, 4B, 4C. Similarly, the heat radiation surface 4A7 that radiates the heat received by the heat receiving surface 4A6 may be a part of the outer surfaces of the holders 4A, 4B, 4C.

The heat radiation fins 4A8 may be provided only in a part of the heat radiation surface 4A7, or the heat radiation fins 4A8 may not be provided.

In each of the above embodiments, the light modulation element 35 includes the incident-side polarizing plate 351, the liquid crystal panel 352, and the exit-side polarizing plate 355. The incident-side polarizing plate 351 and the liquid crystal panel 352 are disposed apart from each other so that a part of the 1 st spaces SP1, SP2, SP3 exists. The emission-side polarizing plate 355 is fixed to the liquid crystal panel 352 so as to be in contact with the light emission surface 3522 of the liquid crystal panel 352. However, the present invention is not limited thereto, and the incident-side polarizing plate 351 may be fixed to the liquid crystal panel 352 so as to be in contact with the light incident surface 3521 of the liquid crystal panel 352, and the exit-side polarizing plate 355 may be provided separately from the liquid crystal panel 352.

In each of the embodiments described above, the light incident surface 3511 of the incident-side polarizing plate 351 is exposed to the 1 st spaces SP1, SP2, and SP3. However, the light incident surface 3511 is not limited thereto, and may be exposed to the outside of the holder. For example, the 1 st opening 4A1 of the holder may be closed by the incident-side polarizing plate 351.

Similarly, the light exit surface 3552 of the exit-side polarizing plate 355 is exposed in the 1 st spaces SP1, SP2, and SP 3. However, the light emitting surface 3552 is not limited thereto, and may be exposed to the outside of the holder.

In each of the above embodiments, the projectors 1A, 1B, 1C are provided with the 1 st cooling fan 71 and the 2 nd cooling fan 72 as the holder external fans. However, the present invention is not limited to this, and at least one of the 1 st cooling fan 71 and the 2 nd cooling fan 72 may not be provided. In the case where the cooling medium is disposed in the outer case and the circulation fan for circulating the cooling medium through the outer surface of the holder is provided in the outer case, the outer case may not have the inlet 2A5 and the outlet 2A6.

In embodiment 1 described above, the 1 st opening 4A1 of the holder 4A is closed by the 1 st lens 34, and the 2 nd opening 4A2 is closed by the 2 nd lens 36. In embodiment 2 described above, the 1 st opening 4A1 of the holder 4B is closed by the base member 32, and the 2 nd opening 4A2 is closed by the 2 nd lens 36. In embodiment 3 described above, the 1 st opening 4A1 of the holder 4C is closed by the 1 st lens 34, and the 2 nd opening 4A2 is closed by the projection lens 38. However, the present invention is not limited to this, and the structure for closing the 1 st opening 4A1 may be other optical members constituting the image projection unit 3 or may be a light-transmitting member provided separately. Similarly, the structure for closing the 2 nd opening 4A2 may be another optical member constituting the image projection unit 3 or may be a light-transmitting member provided separately.

In embodiment 3, the circulation fan 8 as an in-holder fan for circulating the cooling medium through the light modulation element 35 is provided in the holder 4C. However, the present invention is not limited thereto, and the circulation fan 8 may not be provided. The number of circulation fans 8 disposed in the holder 4C is not limited to 1, and may be appropriately changed. In the case where another heat source HS such as the light source 31 is disposed in the holder 4C, the circulation fan 8 may circulate the cooling medium through the other heat source HS.

In each of the above embodiments, the light modulation element 35 includes the liquid crystal panel 352 including the transmissive liquid crystal element 353. However, the light modulation element 35 is not limited to this, and may be provided with a reflective liquid crystal element that emits image light in a direction opposite to the incident direction of light, instead of the transmissive liquid crystal element 353. The light modulator 35 may be a light modulator other than liquid crystal. Depending on the light modulation element used, the exit-side polarizer 355 can be omitted.

The liquid crystal panel 352 may not include the color filter 354, and the color filter 354 may be a monochrome color filter as described above.

Further, in the case where the light emitted from the light source 31 is linearly polarized, the incident-side polarizing plate 351 may be omitted.

In each of the above embodiments, the 1 st lens 34 and the 2 nd lens 36 are fresnel lenses. However, the present invention is not limited to this, and at least one of the 1 st lens 34 and the 2 nd lens 36 may be a fresnel lens. Also, for example, the image projection unit 3 may include other optical components in addition to the above-described optical components.

In each of the above embodiments, the image projection unit 3 includes the optical path changing member 37, and the optical path changing member 37 changes the optical path of the image light emitted from the 2 nd lens 36, and makes the image light incident on the projection lens 38. However, the present invention is not limited thereto, and the optical path changing member 37 may not be provided. The optical path changing member 37 changes the optical path of the image light by reflecting the incident image light. However, the optical path changing member is not limited to this, and may be an optical member such as a prism.

In the above embodiments, the projectors 1A, 1B, 1C, 1D are provided with the heat transport member 61 connected to the base member 32 that supports the light source 31 so as to be able to transfer heat, and the heat radiation member 62 that radiates heat of the light source 31 transferred from the heat transport member 61. However, the present invention is not limited thereto, and for example, in the case where the light source 31 is provided in the heat radiating member 62, at least one of the base member 32 and the heat transporting member 61 may not be provided.

The heat transfer member 61 and the heat dissipation member 62 may not be provided as long as the light source 31 can be sufficiently cooled by the cooling medium or the cooling gas.

In the above embodiments, the projectors 1A, 1B, 1C, and 1D are provided with the power supply 5, and the power supply 5 is disposed in the outer cases 2A and 2D to supply power to the light source 31 and the liquid crystal panel 352. However, the power supply 5 may not be necessarily disposed inside the outer cases 2A and 2D. The projector may also include a 1 st power supply that supplies power to the light source 31 and a 2 nd power supply that supplies power to the liquid crystal panel 352. Further, the power supply 5 may supply power to one of the light source 31 and the liquid crystal panel 352.

In each of the above embodiments, the cooling medium filled in the holders 4A, 4B, 4C is any of helium gas, hydrogen gas, and liquid refrigerants of hydrofluoroethers. However, the type of the cooling medium is not limited to this, and may be appropriately changed, and a plurality of types of refrigerants may be mixed and filled in the case.

Summary of the utility model

Hereinafter, a summary of the present utility model will be described.

[ Additional note 1]

A projector, characterized in that it has: a light source that emits white light; a 1 st lens that condenses the white light emitted from the light source; 1 light modulation element which emits image light obtained by modulating the white light incident from the 1 st lens; a 2 nd lens that condenses the image light emitted from the light modulation element; a projection lens that projects the image light emitted from the 2 nd lens; an exterior case accommodating the light source, the 1 st lens, the light modulation element, the 2 nd lens, and the projection lens; a holder having a heating surface on an inner surface thereof, the holder holding the 1 st lens, the light modulation element, and the 2 nd lens, and sealing a 1 st space between a light exit surface of the 1 st lens and a light entrance surface of the 2 nd lens, the light exit surface and the light entrance surface being spaced apart by the light modulation element; and a cooling medium filled in the 1 st space, absorbing heat of the light modulation element, and convecting inside the 1 st space to transfer heat to the heating surface.

According to this configuration, the light modulation element as a heat source is held in the holder closing the 1 st space. The cooling medium filled in the 1 st space absorbs heat from the light modulation element, flows convectively in the 1 st space, and is stirred in the 1 st space. The cooling medium dissipates the absorbed heat to the heated surface of the holder. This allows the light modulation element to be cooled.

Therefore, compared with a structure in which the light modulation element is cooled by circulating a liquid refrigerant, the number of components can be suppressed, and the light modulation element can be cooled by a relatively simple structure. Therefore, even if the brightness of the light source is increased, the light modulation element can be cooled, so that the projector can be miniaturized and the brightness of the projected image of the projector can be increased.

[ Additionally noted 2]

The projector according to the annex 1, wherein the light modulation element includes: a liquid crystal panel; an incident-side polarizing plate disposed on a light incident side of the liquid crystal panel, the light emitted from the 1 st lens being incident on the incident-side polarizing plate; an emission-side polarizing plate disposed on a light emission side of the liquid crystal panel and configured to emit light emitted from the liquid crystal panel toward the 2 nd lens; the incident-side polarizing plate and the liquid crystal panel are separated from each other so that a part of the 1 st space exists.

When the white light emitted from the light source is not 1 type of linearly polarized light, the incident-side polarizing plate disposed on the light incident side of the liquid crystal panel also serves as a heat source that generates heat due to the incident light.

In contrast, the cooling medium convects between the incident-side polarizer and the liquid crystal panel, so that 2 heat sources, i.e., the incident-side polarizer and the liquid crystal panel, can be efficiently cooled.

[ Additionally recorded 3]

The projector according to the appendix 2, wherein the light incident surface of the incident-side polarizing plate is exposed in the 1 st space.

According to this configuration, the light incident surface and the light exit surface of the incident-side polarizing plate are exposed to the 1 st space, respectively. This allows the incident-side polarizing plate to be cooled efficiently by the cooling medium convected in the 1 st space.

[ Additional note 4]

The projector according to any one of supplementary notes 2 and 3, wherein the light-emitting-side polarizing plate is fixed in contact with a light-emitting surface of the liquid crystal panel, and the light-emitting surface of the light-emitting-side polarizing plate is exposed in the 1 st space.

The heat generation amount of the exit-side polarizer is smaller than the heat generation amount of the entrance-side polarizer. Therefore, the exit-side polarizing plate can be cooled even by heat exchange between the light exit surface and the cooling medium.

The light-emitting-side polarizing plate is fixed to the light-emitting surface of the liquid crystal panel held by the holder. This makes it possible to suppress an increase in size of the holder, compared with a case where the holder holds the liquid crystal panel and the emission-side polarizing plate, respectively.

[ Additional note 5]

In the projector according to any 1 of supplementary notes 2 to 4, the liquid crystal panel has: a transmissive liquid crystal element that emits modulated light along a traveling direction of the incident light; and a color filter disposed on the light emission surface of the transmissive liquid crystal element.

According to such a configuration, a color image corresponding to the image signal can be formed by 1 liquid crystal panel.

[ Additional note 6]

In the projector according to any 1 of supplementary notes 1 to 5, the holder has: a 1 st opening through which the white light emitted from the light source passes; and a 2 nd opening through which the image light passes, wherein the 1 st lens exposes a light incident surface of the 1 st lens to a space inside the exterior case, the 1 st opening is closed in a state of sealing the 1 st space, and the 2 nd lens exposes a light emitting surface of the 2 nd lens to a space inside the exterior case, and the 2 nd opening is closed in a state of sealing the 1 st space.

According to this configuration, the 1 st lens closes the 1 st opening in a state where the light incident surface of the 1 st lens is exposed to the space inside the exterior case, and the 2 nd lens closes the 2 nd opening in a state where the light emitting surface of the 2 nd lens is exposed to the space inside the exterior case. Thus, the 1 st space can be sealed by closing each opening without providing a separate member for closing each opening, and thus, the size of the holder and the size of the projector can be suppressed from increasing.

[ Additionally noted 7]

The projector according to any one of supplementary notes 1 to 5, wherein the projector has a base member supporting the light source, and the holder has: a1 st opening portion which is closed in a state where the 1 st space is closed by the base member; and a2 nd opening portion that emits the image light, wherein the 2 nd lens exposes a light emitting surface of the 2 nd lens to a space inside the exterior case, the 2 nd opening portion is closed in a state of closing the 1 st space, and the light source is accommodated in the 1 st space.

According to such a configuration, the cooling medium filled in the 1 st space can exchange heat with the light source. This allows the light modulation element and the light source to be cooled by the cooling medium.

Further, since the 1 st opening is closed by the base member supporting the light source and the 2 nd opening is closed by the 2 nd lens, it is not necessary to provide a separate member for closing each opening. Therefore, the size of the holder and the size of the projector can be suppressed.

[ Additionally recorded 8]

In the projector according to the independent claim 7, a part of the heating surface is disposed on an inner surface of the holder opposite to the light source.

According to this configuration, the heat of the cooling medium heated from the light source can be heated at a part of the heating surface. Therefore, the cooling medium can be promoted to absorb heat from the light source.

In addition, when the heat radiation fin is provided at a position of the outer surface of the holder corresponding to the heating surface, the heat received by the heating surface can be quickly radiated to the outside of the holder. In this case, the heating surface can be promoted to receive heat from the cooling medium, so that heat absorption of the cooling medium from the light source can be further promoted, and the cooling efficiency of the light source can be further improved.

[ Additional note 9]

In the projector according to any 1 of supplementary notes 1 to 5, the holder has: a 1 st opening through which light emitted from the light source passes; and a 2 nd opening through which the image light passes, wherein the 1 st lens closes the 1 st opening in a state of closing the 1 st space, and wherein the projection lens closes the 2 nd opening in a state of closing the 1 st space.

According to this configuration, since the 1 st opening is closed by the 1 st lens and the 2 nd opening is closed by the projection lens, it is unnecessary to provide a separate member for closing each opening. Therefore, the size of the holder and the size of the projector can be suppressed.

[ Additional note 10]

The projector according to any one of supplementary notes 1 to 9, wherein the holder has a plurality of fins arranged on an outer surface on a side opposite to the heating surface.

According to this structure, the plurality of fins can improve the heat radiation performance of the heat received by the heating surface. This can maintain the temperature difference between the heat source and the heating surface, and therefore, stirring in the 1 st space due to convection of the cooling medium can be promoted.

[ Additional note 11]

The projector according to the attached document 10 is characterized in that the projector includes a holder outer fan disposed in the outer case so as to circulate the cooling gas through the plurality of fins.

According to this structure, the heat radiation performance of the plurality of heat radiation fins provided in the holder with respect to the heat source can be improved.

[ Additional note 12]

The projector according to the attached document 11 is characterized by comprising an in-holder fan disposed in the holder so as to circulate the cooling medium through the light modulation element.

According to this configuration, the cooling gas is circulated through the light modulator by the intra-holder fan, whereby the cooling efficiency of the light modulator can be improved.

[ Additional note 13]

The projector according to any one of supplementary notes 11 and 12, wherein the exterior case has an inlet provided on an outer surface of the light source side opposite to the outer surface of the light source side when the outer surface of the light source side is opposed to the mounting surface, and a part of the heating surface is provided on an inner surface of the holder opposite to the mounting surface.

According to this configuration, the cooling medium having absorbed heat from the light modulator flows in the 1 st space in the holder to the side opposite to the mounting surface. Therefore, by providing a part of the heating surface on the inner surface on the opposite side from the mounting surface among the inner surfaces of the holder, heat can be efficiently received from the cooling medium with heat. Therefore, the cooling medium can be promoted to absorb heat from the heat source.

In addition, when the heat radiation fin is provided at a position of the outer surface of the holder corresponding to the heating surface, the heat received by the heating surface can be quickly radiated to the outside of the holder. In this case, the heating surface can be promoted to receive heat from the cooling medium, so that heat absorption of the cooling medium from the light modulation element can be further promoted, and the cooling efficiency of the light modulation element can be further improved.

[ Additional note 14]

The projector according to any one of supplementary notes 1 to 13, wherein at least one lens of the 1 st lens and the 2 nd lens is a fresnel lens.

According to such a configuration, the optical path length from the light source to the projection lens can be shortened. Therefore, the downsizing of the holder and the downsizing of the projector can be achieved.

[ Additional note 15]

The projector according to any one of supplementary notes 1 to 14, wherein the cooling medium is any one of helium, hydrogen, and a liquid of hydrofluoroethers.

By using the above-listed cooling medium having high thermal conductivity or the cooling medium having high specific heat as the cooling medium, the cooling performance of the light modulation element can be improved.

Claims

1. A projector, characterized in that it has:

a light source that emits white light;

A 1 st lens that condenses the white light emitted from the light source;

1 light modulation element which emits image light obtained by modulating the white light incident from the 1 st lens;

a 2 nd lens that condenses the image light emitted from the light modulation element;

a projection lens that projects the image light emitted from the 2 nd lens;

An exterior case accommodating the light source, the 1 st lens, the light modulation element, the 2 nd lens, and the projection lens;

A holder having a heating surface on an inner surface thereof, the holder holding the 1 st lens, the light modulation element, and the 2 nd lens, and sealing a 1 st space between a light exit surface of the 1 st lens and a light entrance surface of the 2 nd lens, the light exit surface and the light entrance surface being spaced apart by the light modulation element; and

And a cooling medium filled in the 1 st space, absorbing heat of the light modulation element, and convecting inside the 1 st space to transfer heat to the heating surface.

2. The projector according to claim 1, wherein,

The light modulation element has:

A liquid crystal panel;

An incident-side polarizing plate disposed on a light incident side of the liquid crystal panel, the light emitted from the 1 st lens being incident on the incident-side polarizing plate;

An emission-side polarizing plate disposed on a light emission side of the liquid crystal panel and configured to emit light emitted from the liquid crystal panel toward the 2 nd lens;

the incident-side polarizing plate and the liquid crystal panel are separated from each other so that a part of the 1 st space exists.

3. The projector according to claim 2, wherein,

The light incident surface of the incident-side polarizing plate is exposed in the 1 st space.

4. The projector according to claim 2, wherein,

The exit-side polarizing plate is fixed in contact with the light exit surface of the liquid crystal panel,

The light exit surface of the exit-side polarizer is exposed in the 1 st space.

5. The projector according to any one of claims 2 to 4, wherein,

The liquid crystal panel has:

A transmissive liquid crystal element that emits modulated light along a traveling direction of the incident light; and

And a color filter disposed on the light emitting surface of the transmissive liquid crystal element.

6. The projector according to any one of claims 1 to 4, wherein,

The retainer has:

A 1 st valve communicating with the 1 st space; and

And a2 nd valve communicating with the 1 st space.

7. The projector according to any one of claims 1 to 4, wherein,

The retainer has:

A1 st opening through which the white light emitted from the light source passes; and

A 2 nd opening portion through which the image light passes,

The 1 st lens exposes the light incident surface of the 1 st lens in the space inside the outer case, closes the 1 st opening in a state of closing the 1 st space,

The 2 nd lens exposes a light emitting surface of the 2 nd lens to a space inside the outer case, and closes the 2 nd opening while closing the 1 st space.

8. The projector according to any one of claims 1 to 4, wherein,

The projector has a base member supporting the light source,

The retainer has:

A 1 st opening portion which is closed in a state where the 1 st space is closed by the base member; and

A2 nd opening portion which emits the image light,

The 2 nd lens exposes the light emitting surface of the 2 nd lens in the space inside the outer case, and closes the 2 nd opening in a state of closing the 1 st space,

The light source is housed in the 1 st space.

9. The projector according to claim 8, wherein,

A portion of the heating surface is disposed on an inner surface of the holder opposite the light source.

10. The projector according to any one of claims 1 to 4, wherein,

The retainer has:

a1 st opening through which light emitted from the light source passes; and

A 2 nd opening portion through which the image light passes,

The 1 st lens seals the 1 st opening part in a state of sealing the 1 st space,

The projection lens closes the 2 nd opening while closing the 1 st space.

11. The projector according to any one of claims 1 to 4, wherein,

The holder has a plurality of fins arranged on an outer surface on a side opposite to the heating surface.

12. The projector according to claim 11, wherein,

The projector includes a holder outer fan disposed in the outer case to circulate a cooling gas through the plurality of fins.

13. The projector according to claim 12, wherein,

The projector includes a holder internal fan disposed in the holder to circulate the cooling medium through the light modulation element.

14. The projector according to claim 12, wherein,

The outer housing has an inlet provided on an outer surface of the light source side opposite to the outer surface of the light source side when the outer surface of the light source side is opposite to the mounting surface,

A part of the heating surface is provided on an inner surface of the holder on a side opposite to the mounting surface.

15. The projector according to any one of claims 1 to 4, wherein,

At least one of the 1 st lens and the 2 nd lens is a fresnel lens.

16. The projector according to any one of claims 1 to 4, wherein,

The cooling medium is any one of helium, hydrogen and hydrofluoroether type liquid.