Projection-type video display device

Abstract

This projection-type video display device comprises: a light source unit that emits light; a light modulation unit that modulates the light from the light source unit to generate video light; a projection lens unit that has a plurality of lenses and projects the video light; a power supply board that drives and controls a light source; a sealed housing that accommodates the light source unit, the power supply board, the light modulation unit, and the projection lens unit; a heat exchanger that performs heat exchange between gas inside the sealed housing and gas outside the sealed housing; a partition wall that is provided in the sealed housing and divides the inside of the sealed housing into a first space and a second space; and a fan that sequentially sends the gas inside the sealed housing from the heat exchanger to the second space via the first space.

Description

Projection-type image display device

[0001] The present invention relates to a projection-type image display device.

[0002] Conventionally, there has been a projection-type image display device that modulates illumination light from a light source into image light using a light modulation element and projects the modulated image light. A DMD (Digital Micromirror Device) or a liquid crystal element is used as the light modulation element. Such projection-type image display devices are used in various indoor locations. An example of such a projection-type image display device is the projection-type image display device (projector) disclosed in Patent Document 1.

[0003] International Publication No. 2019 / 225679

[0004] However, when a projection-type image display device is used outdoors, the amount of dust that gets into the projection-type image display device is greater than when it is used indoors, and rain can also cause water to get in. This can sometimes shorten the lifespan of the projection-type image display device.

[0005] An object of the present disclosure is to provide a projection-type video display device that prevents its lifespan from being shortened even when used outdoors.

[0006] The projection-type image display device according to the present disclosure includes a light source unit that emits light, a light modulation unit that modulates the light from the light source unit to generate image light, a projection lens unit having a plurality of lenses and projecting the image light, a power supply board that drives and controls the light source, a sealed housing that houses the light source unit, the power supply board, the light modulation unit, and the projection lens unit, a heat exchanger that exchanges heat between gas inside the sealed housing and gas outside the sealed housing, a partition wall that is provided inside the sealed housing and divides the inside of the sealed housing into a first space and a second space, and a fan that sequentially sends gas inside the sealed housing from the heat exchanger through the first space to the second space.

[0007] The present disclosure can provide a projection-type video display device that prevents its lifespan from being shortened even when used outdoors.

[0008] A perspective view of the appearance of the projection-type image display device according to the first embodiment. A plan view showing the configuration of the projection-type image display device according to the first embodiment with the top panel removed. A longitudinal sectional view of a heat exchanger. A perspective view of a projection lens unit. A perspective view showing the configuration of a light modulation element and liquid cooling. An explanatory diagram showing the configuration of a liquid cooling system. An explanatory diagram explaining the flow of gas inside the sealed housing of the projection-type image display device.

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of well-known matters or redundant explanation of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following explanation and to facilitate understanding by those skilled in the art.

[0010] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0011] (Embodiments) [1-1. Configuration of Projection-Type Video Display Device] A projection-type video display device 1 according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is an external perspective view of the projection-type video display device 1 according to the first embodiment. The projection-type video display device 1 according to the first embodiment is, for example, a so-called three-chip DMD projector that uses three DMDs. Note that liquid crystal elements may be used instead of the DMDs.

[0012] The projection-type image display device 1 of the first embodiment includes a housing 2. The housing 2 has a substantially rectangular parallelepiped shape and includes a frame 12 that forms each side of the rectangular parallelepiped. The housing 2 further includes a top plate 3 and a bottom plate 4, and four side plates 5, 6, 7, and 8 that face each other. The frame 12 supports the top plate 3, bottom plate 4m, and side plates 5-8, each made of metal or resin, and the top plate 3, bottom plate 4m, and side plates 5-8 are fixed to the frame 12. Note that the housing 2 may also include the metal top plate 3, bottom plate 4m, and side plates 5-8, which may be connected by welding without the frame 12. Image light is projected from the side plate 5. The side plates 5 and 6 face each other. The side plate 7 is connected to the side plates 5 and 6 via the frame 12, and an air intake 9 is provided through which outside air flows into the housing 2. The side plate 8 is connected to the side plates 5 and 6 via a frame 12, and is provided with an exhaust port 10 through which outside air that has flowed into the housing 2 flows out again to the outside of the housing 2. The intake port 9 and the exhaust port 10 each have a plurality of holes 11. The top plate 3 is detachably fastened to the four side plates 5 to 8. An enclosed space S1 and an unsealed space S2 are arranged within the housing 2. The enclosed space S1 is sealed to a liquid-tight state, preventing liquid from flowing in from the outside. Therefore, dust and dirt are prevented from flowing into the enclosed space S1.

[0013] Next, reference is made to Fig. 2. Fig. 2 is a plan view showing the configuration of the projection type image display device 1 according to the embodiment with the top panel 3 removed.

[0014] The projection-type image display device 1 includes a power supply board 13, a light source unit 15, a light modulation unit 17, and a projection lens unit 19. The power supply board 13, the light source unit 15, the light modulation unit 17, and the projection lens unit 19 are arranged in an enclosed space S1.

[0015] The power supply board 13 converts the power supplied from an external power source via a cable 21 into direct current and supplies the driving power to the projection-type image display device 1. The power supply board 13 also controls the power supplied to the light source unit 15, thereby controlling the amount of light emitted from the light source unit 15.

[0016] The power supply boards 13 each have an integrated circuit that can be realized using semiconductor elements or the like, and can be configured, for example, with a microcomputer, CPU, MPU, GPU, DSP, FPGA, or ASIC. Each power supply board 13 realizes a predetermined function by reading data and programs stored in a built-in memory unit (not shown) and performing various arithmetic processing. The memory unit can be realized, for example, with a hard disk drive (HDD), SSD, RAM, DRAM, ferroelectric memory, flash memory, magnetic disk, or a combination of these.

[0017] The light source unit 15 includes, for example, multiple laser light sources and a phosphor wheel. For example, laser light in the blue wavelength range emitted from the multiple laser light sources is branched and enters the phosphor wheel, where it is converted into laser light in the yellow wavelength range. The laser light in the yellow wavelength range and the laser light in the blue wavelength range are mixed to generate white light, which is emitted from the light source unit 15 to the light modulation unit 17 via a relay optical system. The relay optical system includes multiple lenses and mirrors, and guides the white light emitted from the light source unit 15 to the light modulation unit 17.

[0018] The light modulation unit 17 modulates the incident white light in accordance with an input video signal to generate video light, and outputs this video light to the projection lens unit 19. The light modulation unit 17 outputs colored light in accordance with an image signal synchronized with each colored light transmitted from a signal board included in the power supply board 13. The light modulation unit 17 includes a light separation element (e.g., a prism or a dichroic mirror) that separates the incident white light into multiple colored lights, a light modulation element 17a that modulates each of the separated colored lights in accordance with the video signal, and a light combining element (e.g., a prism) that combines the modulated colored lights into video light. The light separation element and the light combining element may be the same prism.

[0019] The light modulation element 17a may be, for example, a DMD that changes the angle of a micromirror to change the traveling direction of light, or a liquid crystal element. In the embodiment, an example of a DMD will be described as the light modulation element 17a.

[0020] The projection lens unit 19 includes a plurality of lenses 19a, 19b, and 19c and a lens barrel 19d that supports each lens, and projects the image light incident from the light modulation unit 17 onto a screen (not shown) in an enlarged form. In the embodiment, the projection lens unit 19 is described as including three lenses for the sake of simplicity, but is not limited to this and may include more lenses. The arrangement direction of the plurality of lenses 19a, 19b, and 19c is defined as a first direction.

[0021] The signal board of the power supply board 13 controls the angle of the micromirror of each light modulation element 17a to a first angle or a second angle in synchronization with the input image signal. The light reflected at the first angle is emitted as image light, and the light reflected at the second angle is absorbed as unwanted light.

[0022] The projection display device 1 further includes a heat exchanger 22 and fans 23 and 25. The fans 23 and 25 are disposed within the space S2.

[0023] The heat exchanger 22 includes a flow path F1 communicating with the sealed space S1 and a flow path F2 communicating with the space S2, and heat exchange occurs between the flow path F1 and the flow path F2. The flow path F1 and the flow path F2 are separated by a partition wall 22a. The partition wall 22a is, for example, a metal plate. The heat exchanger 22 includes flow paths F1a and F2a that alternately overlap each other, and high-temperature gas flowing through the flow path F1a is cooled by outside air flowing through the flow path F2a. The heat exchanger 22 may have a configuration in which multiple fins protrude from the flow path F1 into the flow path F2, or may use a heat pipe instead of the partition wall 22a or fins to exchange heat. The flow path F1 has an intake port F1c communicating with the second space Sp2 via the fan 35 and an exhaust port F1d communicating with the first space Sp1.

[0024] The fan 25 draws in outside air through the intake port 9 and sends it to the flow path F2 of the heat exchanger 22. The fan 23 exhausts the gas that has flowed out of the flow path F2 of the heat exchanger 22 to the outside through the exhaust port 10.

[0025] [1-2. Configuration within the sealed space S1] The sealed space S1 is a space surrounded by portions of the top plate 3, bottom plate 4, side plate 7, and side plate 8, the side plate 5, and the partition wall 22a of the heat exchanger 22. The top plate 3, bottom plate 4, side plate 7, and side plate 8, the side plate 5, and the partition wall 22a of the heat exchanger 22 form the sealed housing 2a. Sealing members such as packing are arranged between the frame 12 and the top plate 3 and the side plates 5, 7, and 8, and the seal is maintained when the top plate 3 and the side plates 5 to 8 are fixed to the frame 12.

[0026] The sealed space S1 within the sealed housing 2a is divided into a first space Sp1, a second space Sp2, and a third space Sp3. The first space Sp1 and the second space Sp2 are separated by a partition wall 27. The third space Sp3 is the space within the heat exchanger 22. The partition wall 27 is made of a metal or resin wall material. The lower end of the partition wall 27 is connected to the bottom plate 4, and the upper end of the partition wall 27 is connected to the top plate 3.

[0027] The power supply substrate 13 is disposed in the first space Sp1. A heat receiving portion 29 is disposed at the boundary between the first space Sp1 and the second space Sp2, and is provided, for example, on the partition wall 27. The gas in the first space Sp1 flows into the second space Sp2 through the heat receiving portion 29, and the heat receiving portion 29 absorbs heat from the air flowing from the first space Sp1 to the second space Sp2. The heat receiving portion 29 is, for example, a radiator.

[0028] The projection lens unit 19, the light modulation unit 17, and the light source unit 15 are arranged in the second space Sp2. The light modulation unit 17 has a heat receiving unit 31, and the light source unit 15 has a heat receiving unit 33. The heat receiving unit 31 absorbs heat from the light modulation unit 17, and the heat receiving unit 33 absorbs heat from the light source unit 15. The heat receiving units 31 and 33 are each a metal plate, such as a copper plate.

[0029] A fan 35 is disposed between the light source unit 15 and the heat exchanger 22. The fan 35 draws in gas from the second space Sp2 and causes the gas to flow into the flow path F1 of the heat exchanger 22.

[0030] Please refer to Figures 2 and 4. Figure 4 is a perspective view of the projection lens unit 19. A cover member 37 is provided to surround the side surface of the tip of the lens barrel 19d on the projection side of the projection lens unit 19. The cover member 37 is connected to the bottom plate 4 and the side plate 5, and supports the tip of the lens barrel 19d on the projection side. The cover member 37 is connected to the side plate 5 via a cushioning material such as sponge.

[0031] The side plate 5 has an opening 5a on an extension of the projection direction of the barrel 19d of the projection lens unit 19. A transparent member 5b is arranged to cover the opening 5a from the inside of the side plate 5. The transparent member 5b is a colorless, transparent member that transmits image light, and is, for example, a glass plate or a resin member. The transparent member 5b is arranged on an extension of the tip side of the barrel 19d of the projection lens unit 19, and the image light projected from the projection lens unit 19 passes through the transparent member 5b.

[0032] Please refer to Figures 2, 5, and 6. Figure 5 is a perspective view showing the configuration of the light modulation element 17a and liquid cooling. Figure 6 is an explanatory diagram showing the configuration of the liquid cooling system 30. The liquid cooling system 30 includes a heat receiving section 31, an inlet pipe 43, an outlet pipe 45, and a radiator 47. The heat receiving section 31 includes a heat receiving plate 39 and a flow path section 41.

[0033] One surface of the heat receiving plate 39 is in contact with the rear surface of the optical modulation element 17 a via grease, and receives the heat generated by driving the optical modulation element 17 a. The other surface of the heat receiving plate 39 is in contact with the flow path portion 41, and the heat of the heat receiving plate 39 is dissipated to the flow path portion 41.

[0034] A refrigerant flows through the flow path portion 41, and heat from the heat receiving plate 39 is transferred to the refrigerant in the flow path portion 41. The heat receiving portion 31 includes an inlet pipe 43 through which the refrigerant flows into the flow path portion 41, and an outlet pipe 45 through which the refrigerant flows out of the heat receiving portion 31. The refrigerant that flows in from the inlet pipe 43 absorbs heat from the optical modulation element 17a and increases in temperature. The heat receiving portion 31 has a built-in pump, and the refrigerant whose temperature has increased flows out from the flow path portion 41 through the outlet pipe 45 and into the radiator 47. The refrigerant is cooled in the radiator 47, and the cooled refrigerant circulates back to the heat receiving portion 31.

[0035] Referring to FIG. 2 , radiators 49, 47, and 51 are arranged along the side panel 6 in the unsealed space S2. Similar to the liquid-cooling system 30, a liquid-cooling system is configured in which a refrigerant circulates between the radiator 49 and the heat-receiving unit 29. Heat absorbed by the heat-receiving unit 29 is dissipated in the radiator 49 via the refrigerant. Similarly to the liquid-cooling system 30, a liquid-cooling system is configured in which a refrigerant circulates between the radiator 51 and the heat-receiving unit 33. Heat absorbed by the heat-receiving unit 33 is dissipated in the radiator 51 via the refrigerant. By including such a liquid-cooling system, the projection-type image display device 1 can directly cool the gas that cools the light source unit 15, the optical modulation unit 17, and the power supply board 13, which are high-heat sources, using gas outside the sealed housing 2a via liquid cooling, thereby reducing the amount of heat required for air cooling by the heat exchanger 22. This allows the size of the heat exchanger 22 to be reduced, thereby achieving a compact projection-type image display device 1 overall.

[0036] [1-3. Flow of Cooling Air] Next, the flow of gas within the sealed space S1 of the projection-type image display device 1 according to the embodiment will be described with reference to Fig. 7. Fig. 7 is an explanatory diagram illustrating the flow of gas within the sealed housing 2a of the projection-type image display device 1. The gas flowing within the sealed space S1 is, for example, air.

[0037] Outside air is drawn in through the intake port 9 by the fan 25 and flows into the flow path F2 of the heat exchanger 22. The gas flowing through the flow path F1 of the heat exchanger 22, which is the third space Sp3 of the sealed space S1, is cooled by the outside air flowing through the flow path F2. The cooled gas flows into the first space Sp1 from the exhaust port F1d of the flow path F1 of the heat exchanger 22. The gas that flows into the first space Sp1 cools the power supply board 13. The gas that has been heated by the power supply board 13 flows from the first space Sp1 to the second space Sp2 through the heat receiving portion 29. The heat receiving portion 29 absorbs heat from the gas passing through, so the gas is cooled again.

[0038] The cooled gas collides with the side plate 5, changes its flow direction, and flows through the projection lens unit 19 along the surface of the cover member 37, cooling the lenses 19a to 19c of the projection lens unit 19 via the lens barrel 19d. Because the cover member 37 prevents gas from flowing on the projection side of the lens 19c, it is possible to prevent the cooling air from causing fluctuations in the projected image light.

[0039] The gas that has cooled the projection lens unit 19 passes through the light modulation unit 17 to cool optical elements such as lenses and prisms. The gas that has cooled the light modulation unit 17 further passes through the light source unit 15 to cool optical elements such as a phosphor wheel and a collimator lens.

[0040] The gas that has cooled the light source unit 15 is forced to flow out through the intake port F1c of the flow path F1 of the heat exchanger 22 by the fan 35. Inside the heat exchanger 22, heat exchange occurs between the gas, which has been heated by passing through the sealed space S1, and the outside air. The heated outside air is then exhausted to the outside through the flow path F2 of the heat exchanger 22 and the exhaust port 10 by the fan 23. In this way, the gas that has flowed out from the third space Sp3 of the heat exchanger 22 through the exhaust port F1d into the first space Sp1 passes through the power supply board 13, and further passes through the projection lens unit 19, the light modulation unit 17, and the light source unit 15 in the second space Sp2, and flows into the third space Sp3 through the intake port F1c of the heat exchanger 22. This circulates and flows sequentially within the sealed space S1, thereby efficiently cooling the sealed space S1. In this way, by connecting the gas flow path within the sealed space S1 in a single loop from the exhaust port F1d to the intake port F1c of the heat exchanger 22 and arranging the objects to be cooled in order on the flow path, it is possible to minimize the flow path required within the sealed space S1. This makes it possible to eliminate space other than where the heat exchanger 22 is located, thereby reducing wasted space and realizing a more compact housing 2.

[0041] 2. Effects, etc. As described above, the projection-type image display device 1 of the embodiment includes: light source unit 15 that irradiates light; light modulation unit 17 that modulates the light from light source unit 15 to generate image light; projection lens unit 19 having a plurality of lenses 19a to 19c and projecting the image light; power supply board 13 that drives and controls light source unit 15; sealed housing 2a that houses light source unit 15, power supply board 13, light modulation unit 17, and projection lens unit 19; heat exchanger 22 that exchanges heat between gas inside sealed housing 2a and gas outside sealed housing 2a; partition wall 27 that is provided inside sealed housing 2a and divides the inside of sealed housing 2a into a first space Sp1 and a second space Sp2; and fan 35 that sends gas inside sealed housing 2a sequentially from heat exchanger 22 to the second space Sp2 via the first space Sp1.

[0042] The sealed housing 2a houses the light source unit 15, the power supply board 13, the light modulation unit 17, and the projection lens unit 19, which reduces the intrusion of dust and water into the light source unit 15, the power supply board 13, the light modulation unit 17, and the projection lens unit 19, thereby preventing a shortened lifespan of the projection-type image display device 1. In particular, because the power supply board 13 is also housed within the sealed housing 2a, deterioration is also reduced even when used outdoors. Furthermore, the interior of the sealed housing 2a is divided into a first space Sp1 and a second space Sp2 by the partition wall 27, and the gas inside the sealed housing 2a cooled by the heat exchanger 22 is sent sequentially from the first space Sp1 to the second space Sp2, creating a unidirectional flow of cooling air within the sealed housing 2a, thereby increasing cooling efficiency.

[0043] Furthermore, since the cover member 37, which covers at least a portion of the periphery of the lens 19c on the projection side of the projection lens unit 19, is connected to the sealed housing 2a, it is possible to reduce the air inside the sealed housing 2a from flowing to the projection side of the lens 19c on the projection side of the projection lens unit 19, thereby reducing fluctuations in the projected image light.

[0044] Furthermore, the gas cooled by the heat exchanger 22 flows from the heat exchanger 22 into the power supply board 13. The gas that has passed through the power supply board 13 flows into the projection lens unit 19 from a first direction that intersects with the arrangement direction of the multiple lenses 19a to 19c in the projection lens unit 19. The gas that has passed through the projection lens unit 19 flows into the heat exchanger 22. The cover member 37 extends in a direction that intersects with the first direction.

[0045] Since the cover member 37 extends in a direction intersecting with the first direction intersecting with the arrangement direction of the lenses 19a to 19c in the projection lens unit 19, the gas flows along the cover member 37. This makes it possible to reduce gas from getting around the lens 19c on the projection side of the projection lens unit 19, thereby reducing fluctuations in the projected image and dust from being reflected in the image.

[0046] The projection-type image display device 1 also includes heat receiving sections 29, 31, and 33 arranged inside the sealed housing 2a, and radiators 47, 49, and 51 arranged outside the sealed housing 2a and dissipating heat absorbed by the heat receiving sections 29, 31, and 33. The heat receiving sections 29, 31, and 33 exchange heat with the radiators 49, 47, and 51, respectively, via liquid. This further improves the cooling effect inside the sealed housing 2a.

[0047] Furthermore, the heat receiving section 33 absorbs heat from the light source section 15. This makes it possible to further improve the cooling effect of the light source section 15.

[0048] Furthermore, the heat receiving section 31 absorbs heat from the optical modulation section 17. This makes it possible to further improve the cooling effect of the optical modulation section 17.

[0049] Furthermore, the power supply board 13 is disposed in the first space Sp1, and the projection lens unit 19, the light modulation section 17, and the light source section 15 are disposed in the second space Sp2. Since only the power supply board 13 is disposed in the first space Sp1, the cooling effect of the power supply board 13 can be improved by the gas cooled by the outside air.

[0050] Furthermore, the heat receiving section 29 is disposed at the boundary between the first space Sp1 and the second space Sp2, and absorbs heat from the gas flowing from the first space Sp1 to the second space Sp2. This allows the gas, which has been heated by cooling the power supply board 13, to be cooled by the heat receiving section 29 as it flows from the first space Sp1 to the second space Sp2. The cooled air flows again into the second space Sp2, thereby further improving the cooling effect of the projection lens unit 19, the light modulation section 17, and the light source section 15, which are disposed in the second space Sp2.

[0051] (Other Embodiments) As described above, the embodiments have been described as examples of the technology of the present disclosure. For this purpose, the accompanying drawings and detailed description have been provided. Therefore, among the components described in the accompanying drawings and detailed description, not only components essential for solving the problem but also components that are not essential for solving the problem in order to exemplify the above technology may be included. Therefore, the fact that these non-essential components are described in the accompanying drawings or detailed description should not be interpreted as immediately determining that these non-essential components are essential.

[0052] (1) In the above-described embodiment, the sealed space S1 is a liquid-tight space that prevents the intrusion of dust and other particles and prevents the intrusion of liquids such as water from the outside. However, this is not limited to this. The sealed space S1 may be an airtight space that blocks the inflow and outflow of gases from the outside. In this case, the gas in the sealed space S1 is not limited to air, and helium or argon may also be used.

[0053] (2) In the above-described embodiment, the heat receiving portion 29 is disposed at the boundary between the first space Sp1 and the second space Sp2. However, this is not limitative. The heat receiving portion 29 may be omitted.

[0054] (3) In the above-described embodiment, the cover member 37 surrounds the entire side surface of the tip of the barrel 19d of the projection lens unit 19 on the projection side, but this is not limited to this. The cover member 37 surrounds at least a portion of the side surface of the tip of the barrel 19d of the projection lens unit 19 on the projection side, thereby preventing gas from flowing toward the tip of the projection lens unit 19. The cover member 37 may be, for example, a wall standing upright from the bottom plate 4 between the projection lens unit 19 and the heat receiving portion 29, or may have an inverted L-shape, standing upright from the bottom plate 4 and extending along the side plate 5 in a direction perpendicular to the arrangement direction of the multiple lenses 19a to 19c.

[0055] Furthermore, since the above-described embodiments are intended to illustrate the technology of the present disclosure, various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents. Furthermore, it is also possible to combine the components described in the above embodiments to create new embodiments.

[0056] (Summary of the embodiment) (1) The projection type image display device of the present disclosure includes a light source unit that irradiates light, a light modulation unit that modulates the light from the light source unit to generate image light, a projection lens unit having a plurality of lenses and projecting the image light, a power supply board that drives and controls the light source, a sealed housing that houses the light source unit, the power supply board, the light modulation unit, and the projection lens unit, a heat exchanger that exchanges heat between gas inside the sealed housing and gas outside the sealed housing, a partition wall that is provided inside the sealed housing and divides the inside of the sealed housing into a first space and a second space, and a fan that sequentially sends gas inside the sealed housing from the heat exchanger through the first space to the second space.

[0057] The sealed housing houses the light source section, the power supply board, the light modulation section, and the projection lens unit, thereby reducing the intrusion of dust and water into the light source section, the power supply board, the light modulation section, and the projection lens unit, thereby extending the life of the projection type image display device.

[0058] (2) The projection type image display device of (1) further includes a cover member that covers at least a part of the periphery of the lens closest to the projection side of the projection lens unit, and the cover member is connected to the sealed housing.

[0059] Since the cover member that covers at least a portion of the periphery of the lens on the most projection side of the projection lens unit is connected to the sealed housing, it is possible to reduce the air inside the sealed housing from flowing past the projection side of the lens on the most projection side of the projection lens unit, thereby reducing fluctuations in the projected image light. Note that "the cover member is connected to the sealed housing" does not only mean that the cover member is directly connected to the sealed housing, but also includes connection via a sponge or the like.

[0060] (3) In the projection-type image display device of (1) or (2), the gas cooled by the heat exchanger flows from the heat exchanger into the power supply board. The gas that has passed through the power supply board flows into the projection lens unit from a first direction that intersects with the arrangement direction of the lenses in the projection lens unit. The gas that has passed through the projection lens unit flows into the heat exchanger. The cover member extends in a direction that intersects with the first direction.

[0061] (4) In any of the projection-type image display devices (1) to (3), a heat receiving unit is arranged inside the sealed housing, and a radiator is arranged outside the sealed housing and dissipates heat absorbed by the heat receiving unit, and the heat receiving unit exchanges heat with the radiator via a liquid.

[0062] (5) In the projection type image display device of (4), the heat receiving section absorbs heat from the light source section.

[0063] (6) In the projection type image display device of (4) or (5), the heat receiving section absorbs heat from the light modulation section.

[0064] (7) In the projection-type image display device according to any one of (1) to (6), a power supply board is disposed in the first space, and a projection lens unit, a light modulation unit, and a light source unit are disposed in the second space.

[0065] (8) In the projection type image display device of (7), the heat receiving portion is disposed at the boundary between the first space and the second space, and absorbs heat from the gas flowing from the first space to the second space.

[0066] The present disclosure is applicable to a projection-type image display device that projects image light generated by modulating light from a light source unit.

[0067] REFERENCE SIGNS LIST 1 Projection type image display device 2 Housing 2a Sealed housing 3 Top plate 4 Bottom plate 5, 6, 7, 8 Side plate 5a Opening 5b 9 Air intake port 10 Exhaust port 11 Hole 13 Power supply board 15 Light source section 17 Light modulation section 19 Projection lens unit 19a, 19b, 19c Lens 19d Lens barrel 21 Cable 22 Heat exchanger 22a Partition wall 23, 25 Fan 27 Partition wall 29, 31, 33 Heat receiving section 30 Liquid cooling system 35 Fan 37 Cover member 39 Heat receiving plate 41 Flow path section 43 Inlet pipe 45 Outlet pipe 47, 49, 51 Radiator F1, F2 Flow path F1c Air intake port F1d Exhaust port S1 Sealed space S2 Space Sp1 First space Sp2 Second space Sp3 Third space

Claims

1. A projection type image display device comprising: a light source unit that irradiates light; a light modulation unit that modulates the light from the light source unit to generate image light; a projection lens unit having a plurality of lenses and projecting the image light; a power supply board that drives and controls the light source unit; a sealed housing that contains the light source unit, the power supply board, the light modulation unit, and the projection lens unit; a heat exchanger that exchanges heat between a gas inside the sealed housing and a gas outside the sealed housing; a partition provided within the sealed housing that divides the inside of the sealed housing into a first space and a second space; and a fan that sequentially sends the gas inside the sealed housing from the heat exchanger through the first space to the second space.

2. The projection type image display device according to claim 1, further comprising a cover member that covers at least a part of the periphery of the lens on the most projection side of the projection lens unit, the cover member being connected to the sealed housing.

3. The projection type image display device of claim 2, wherein gas cooled by the heat exchanger flows from the heat exchanger into the power supply board, gas passing through the power supply board flows into the projection lens unit from a first direction intersecting with the arrangement direction of the multiple lenses in the projection lens unit, gas passing through the projection lens unit flows into the heat exchanger, and the cover member extends in a direction intersecting with the first direction.

4. The projection type image display device according to claim 1, comprising: a heat receiving section arranged inside the sealed housing; and a radiator arranged outside the sealed housing for radiating heat absorbed by the heat receiving section, wherein the heat receiving section exchanges heat with the radiator via liquid.

5. The projection type image display device according to claim 4, wherein the heat receiving section absorbs heat from the light source section.

6. The projection type image display device according to claim 4, wherein the heat receiving section absorbs heat from the light modulation section.

7. The projection type image display device according to claim 4, wherein the power supply board is disposed within the first space, and the projection lens unit, the light modulation section, and the light source section are disposed within the second space.

8. The projection type image display device according to claim 7, wherein the heat receiving portion is disposed at the boundary between the first space and the second space and absorbs heat of gas flowing from the first space to the second space.

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