Projection display device

Abstract

A projection-type display device according to an embodiment of the present application includes a light source unit, an image forming optical system provided with a spatial modulation element that modulates light emitted from the light source unit, a projection optical system that projects light from the spatial modulation element, a cooling unit having a fan that blows cooling air onto the image forming optical system, and a heat exchanger positioned directly facing the fan.

Description

Technical Field

[0001] This disclosure relates to projection display devices, for example, cooling units including cooling optical systems. Background Technology

[0002] For example, Patent Document 1 discloses a projector having a first circulation path, a second circulation path, and a third circulation path. In the first circulation path, a first refrigerant (gas) circulates to cool a first cooling target disposed in a first space. The first space is substantially sealed. In the second and third circulation paths, a second refrigerant and a third refrigerant (both liquids) that cool the first refrigerant circulate separately. Patent Document 2 discloses a projection display device having a first air passage and a second air passage. The first air passage is disposed in a sealed space. The first air passage cools an illumination optics unit and an image forming unit arranged parallel to each other. The second air passage is disposed between a housing forming a sealed space and a housing that also houses a light source unit in addition to the illumination optics unit and the image forming unit. The second air passage cools the light source unit.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-84777

[0006] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2008-170774 Summary of the Invention

[0007] Incidentally, a quieter projection display device is required.

[0008] Therefore, there is a need to provide a projection display device that allows for quieter operation.

[0009] A projection display apparatus according to an embodiment of the present disclosure includes: a light source unit; an image forming optical system; a projection optical system; a cooling unit; and a heat exchanger. The image forming optical system includes a spatial modulation element that modulates light emitted from the light source unit. The projection optical system projects light from the spatial modulation element. The cooling unit includes a fan that directs cooling air to the image forming optical system. The heat exchanger is arranged facing the fan.

[0010] In the projection display apparatus according to embodiments of the present disclosure, a fan and a heat exchanger disposed in a cooling unit are arranged facing each other. This allows the heat exchanger to eliminate noise generated by the fan. The fan delivers cooling air to an image forming optical system including a spatial modulation element. Attached Figure Description

[0011] [ Figure 1 ] Figure 1 This is a schematic diagram illustrating a projection display device according to an embodiment of the present disclosure.

[0012] [ Figure 2 ] Figure 2 It is shown Figure 1 The diagram shows an example of the configuration of the light source unit.

[0013] [ Figure 3 ] Figure 3 yes Figure 1 A perspective view of an example configuration of the cooling unit and heat exchanger shown in the figure.

[0014] [ Figure 4 ] Figure 4 It is along Figure 3 The cross-sectional view taken from line II is shown in the figure.

[0015] [ Figure 5 ] Figure 5 It is along Figure 3 The cross-sectional view taken from line II-II shown.

[0016] [ Figure 6 ] Figure 6 It shows that the cooling unit and heat exchanger are housed in Figure 1 An illustration of an example of a projection display device shown in the figure.

[0017] [ Figure 7 ] Figure 7 This is a cross-sectional view of another example of the configuration of the cooling unit and heat exchanger according to Modification 1 of this disclosure.

[0018] [ Figure 8 ] Figure 8 This is a cross-sectional view of another example of the configuration of the cooling unit and heat exchanger according to Modification 2 of this disclosure. Detailed Implementation

[0019] Embodiments of this disclosure are described in detail below with reference to the accompanying drawings. The following description illustrates specific examples of this disclosure, but this disclosure is not limited to the following model. Furthermore, this disclosure is not limited to the arrangement, dimensions, size ratios, etc., of the various components shown in the various figures. It should be noted that the description proceeds in the following order.

[0020] 1. Embodiments (including examples of projection display devices in which the fans and heat exchangers in the cooling unit are arranged facing each other)

[0021] 1-1. Configuration of projection display device

[0022] 1-2. Configuration of the cooling unit

[0023] 1-3. Functions and Effects

[0024] 2. Variations

[0025] <1. Implementation Method>

[0026] Figure 1 An example of a schematic configuration of a projection display device (projection display device 1) according to an embodiment of the present disclosure is shown. Projection display device 1 is a projection display device that projects an image (image light) onto a screen 1000 (projection surface), such as a wall. For example, projection display device 1 includes a light source unit 100, an image forming optical system 200, and a projection optical system 300. The image forming optical system 200 includes spatial modulation elements (liquid crystal panels 231R, 231G, and 231B) that each modulate light (illumination light L) emitted from the light source unit 100. The projection optical system 300 projects light (image light) from each of the liquid crystal panels 231R, 231G, and 231B. Projection display device 1 further includes a cooling unit 400 and a heat exchanger 500. The cooling unit 400 includes a fan (e.g., fan 410; see [link]). Figure 3 Cooling air is delivered to the image forming optical system 200. In this embodiment, for example, the fan 410 is positioned directly opposite the heat exchanger 500.

[0027] (1-1. Configuration of the projection display device)

[0028] The projection display device 1 is, for example, a reflective 3LCD projection display device that performs light modulation using a reflective liquid crystal panel (LCD). As described above, the projection display device 1 includes a light source unit 100, an image forming optical system 200, a projection optical system 300, a cooling unit 400, and a heat exchanger 500. For example, the fan 410 included in the cooling unit 400 and the heat exchanger 500 are arranged facing each other. The projection display device 1 further includes a power supply unit 600, a signal processing unit 700, and a heat dissipation unit 800. These components—the light source unit 100, the image forming optical system 200, the projection optical system 300, the cooling unit 400, the heat exchanger 500, the power supply unit 600, the signal processing unit 700, and the heat dissipation unit 800—are housed in a housing 900.

[0029] Figure 2 It shows Figure 1 An example of the configuration of the light source unit 100 shown. The light source unit 100 includes a light source 110, condenser lenses 111A, 111B and 112, a wavelength converter 120, and condenser lenses 130A and 130B.

[0030] Light source 110 is a solid-state light source that outputs light within a predetermined wavelength range. Light source 110 is used to excite phosphor particles included in the phosphor layer of the wavelength converter 12 described below. For example, a semiconductor laser (laser diode: LD) can be used as light source 110. Alternatively, a light-emitting diode (light-emitting diode: LED) can also be used.

[0031] Each condenser lens 111A and 111B has a concave reflective surface that substantially collimates and converges the light flux output from the multiple LDs onto condenser lens 112. The multiple LDs are arranged in light source 110. Condenser lens 112 is used to reflect the light converged by condenser lenses 111A and 111B to wavelength converter 120.

[0032] Wavelength converter 120 converts the light (excitation light EL) output from light source 110 into light (fluorescence FL) in different wavelength ranges and outputs fluorescence FL. Wavelength converter 120 is a so-called transmission wavelength conversion element, for example, a phosphor layer is provided on the front surface of a light-transmitting support substrate. Wavelength converter 120 is configured to output fluorescence FL to the back side of the support substrate. Fluorescence FL is generated by the incoming excitation light EL.

[0033] Condensing lenses 130A and 130B, for example, converge light output from light source 110 and incident on condensing lenses 111A, 111B, and 112 onto condensing lenses 130A and 130B at a predetermined position on wavelength converter 120.

[0034] Light emitted from light source 110 (e.g., blue light) is reflected by condenser lenses 111A, 111B, and 112 to enter condenser lenses 130A and 130B. A predetermined position on wavelength converter 120 is illuminated by light. The wavelength of the light entering wavelength converter 120 is converted in a phosphor layer (e.g., yellow light). The yellow light is output to image forming optical system 200. This yellow light is multiplexed with blue light, for example, emitted from a blue light source (not shown) separately disposed in light source unit 100, and enters image forming optical system 200 as white illumination light L.

[0035] For example, the image forming optical system 200 includes an illumination optical system 210 and an image forming unit 220.

[0036] The illumination optical system 210 includes, from the position closer to the light source unit 100, compound eye lenses 211 (211A and 211B), polarization conversion element 212, lens 213, dichroic mirrors 214A and 214B, reflectors 215A and 215B, relay lenses 216A and 216B, dichroic mirror 217, and polarizers 218R, 218G, and 218B.

[0037] Compound eye lenses 211 (211A and 211B) ensure uniform illuminance distribution of the illumination light L from the light source unit 100. The illumination light L is divided into multiple luminous fluxes by multiple microlenses of compound eye lens 211A. An image of the multiple luminous fluxes is formed on each corresponding microlens of compound eye lens 211B. Each of the multiple microlenses of compound eye lens 211B functions as a secondary light source and outputs multiple parallel beams with uniform brightness to polarization conversion element 212.

[0038] The polarization conversion element 212 aligns the polarization axis of the multiple illumination beams L to provide a predetermined polarization state. The multiple illumination beams L enter the polarization conversion element 212 through compound eye lenses 211 (211A and 211B), etc. For example, the polarization conversion element 212 converts randomly polarized light into P-polarized light. For example, the polarization conversion element 212 outputs the illumination light L through lenses or the like provided on the output side of the light source unit 100. The illumination light L includes red light Lr, green light Lg, and blue light Lb.

[0039] Lens 213 converges the light from polarization conversion element 212 toward dichroic mirrors 214A and 214B.

[0040] Each of the dichroic mirrors 214A and 214B selectively reflects light within a predetermined wavelength range and selectively transmits multiple beams of light within other wavelength ranges. For example, dichroic mirror 214A primarily reflects red light Lr and green light Lg in the direction of reflector 215A. Furthermore, dichroic mirror 214B primarily reflects blue light Lb in the direction of reflector 215B. This separates the illumination light L output from the light source unit 100 into multiple beams of light of different colors (e.g., red light Lr, green light Lg, and blue light Lb).

[0041] Reflector 215A reflects light (mainly red light Lr and green light Lg) from dichroic mirror 214A toward relay lens 216A, and reflector 215B reflects light (mainly blue light Lb) from dichroic mirror 214B toward relay lens 216B.

[0042] Relay lens 216A transmits light (mainly red light Lr and green light Lg) from mirror 215A and focuses the light onto dichroic mirror 217. Relay lens 216B transmits light (mainly blue light Lb) from mirror 215B and focuses the light onto polarizer 218B.

[0043] Dichroic mirror 217 selectively reflects green light Lg and selectively transmits multiple beams of light in other wavelength ranges, oriented toward polarizer 218G.

[0044] Each polarizer 218R, 218G, and 218B includes a polarizer having a polarization axis in a predetermined direction. For example, when light is converted into P-polarized light by polarization conversion element 212, each of polarizers 218R, 218G, and 218B transmits P-polarized light and reflects S-polarized light.

[0045] The image forming unit 220 includes reflective polarizers 221R, 221G and 221B, liquid crystal panels 222R, 222G and 222B for respectively modulating red light Lr, green light Lg and blue light Lb, and a dichroic prism 223.

[0046] Reflective polarizers 221R, 221G, and 221B transmit multiple beams of light (e.g., multiple beams of P-polarized light) having the same polarization axis as the multiple polarized light from polarizers 218R, 218G, and 218B, respectively, and reflect multiple beams of light (multiple beams of S-polarized light) having other polarization axes. Specifically, reflective polarizer 221R transmits P-polarized red light Lr from polarizer 218R in the direction of liquid crystal panel 222R. Reflective polarizer 221G transmits P-polarized green light Lg from polarizer 218G in the direction of liquid crystal panel 222G. Reflective polarizer 221B transmits P-polarized blue light Lb from polarizer 218B in the direction of liquid crystal panel 222B. Furthermore, reflective polarizer 221R reflects S-polarized red light Lr from liquid crystal panel 222R so that the S-polarized red light Lr is incident on dichroic prism 223. A reflective polarizer 221G reflects S-polarized green light Lg from the liquid crystal panel 222G so that the S-polarized green light Lg enters the dichroic prism 223. A reflective polarizer 221B reflects S-polarized blue light Lb from the liquid crystal panel 222B so that the S-polarized blue light Lb enters the dichroic prism 222.

[0047] Liquid crystal panels 222R, 222G, and 222B are electrically coupled to a signal source (e.g., a PC, etc.) that provides image signals including image information. Based on the supplied image signals of each color, liquid crystal panels 222R, 222G, and 222B spatially modulate the red light Lr, green light Lg, and blue light Lb for each pixel to generate a red image, a green image, and a blue image, respectively.

[0048] The dichroic prism 223 combines red light Lr, green light Lg, and blue light Lb modulated by liquid crystal panels 222R, 222G, and 222B, and emits the combined light toward the projection optical system 300.

[0049] The projection optical system 300 includes, for example, multiple lenses. The projection optical system 300 amplifies the image light from the image forming unit 220 and projects the amplified image light onto a screen 1000 or the like.

[0050] Cooling unit 400 is used to cool image forming optical system 200. Although described in detail below, cooling unit 400 includes, for example, one or more fans (e.g., fans 410, 420 and 440).

[0051] The heat exchanger 500 is used to transfer heat generated in the image forming optical system 200 to the heat dissipation unit 800. For example, such as Figure 3 As shown, the heat exchanger 500 has a structure in which a plurality of heat sinks 511, each including, for example, a metal plate, are arranged at predetermined intervals on the lower surface of the housing 900. The heat exchanger 500 is provided, for example, throughout the image forming optical system 200 and the cooling unit 400.

[0052] The power supply unit 600 includes power supply circuits for various optical systems (e.g., light source unit 100, etc.) housed in the housing 900 and for the cooling unit 400. The power supply unit 600 includes multiple components.

[0053] Although not shown, the signal processing unit 700 includes, for example, a light source driver, an image processor, a projection optics system driver, a controller, etc.

[0054] An image processor acquires image signals from external input. For example, the image processor determines the size and resolution of the image and whether the image is still or moving. In the case of moving images, the image processor also determines attributes of image data such as frame rate.

[0055] The projection optics system driver includes a motor that drives a lens disposed in the projection optics system 300. Under the control of a controller, the projection optics system driver drives, for example, the projection optics system 300 and performs functions such as zoom adjustment, focus adjustment, and aperture adjustment.

[0056] The controller controls components such as light source drivers, image processors, and projection optics system drivers.

[0057] The heat dissipation unit 800 is used to dissipate heat generated in the housing 900. Like the heat exchanger 500, the heat dissipation unit 800 has a structure in which multiple heat sinks, each including, for example, metal plates, are stacked at predetermined intervals and coupled to each other, for example, via heat pipes. For example, the heat pipes are also coupled to multiple heat sinks 511 included in the heat exchanger 500. This transfers heat generated in the image forming optical system 200 to the heat dissipation unit 800 via the heat exchanger 500.

[0058] (1-2. Construction of the cooling unit)

[0059] Figure 3 It shows that it includes Figure 1An example of the configuration of multiple fans (fans 410, 420 and 430) and heat exchanger 500 in the cooling unit 400 shown. Figure 4 It shows along Figure 3 The cross-sectional configuration of the cooling unit 400 and heat exchanger 500 shown is taken from line II. Figure 5 It shows along Figure 3 The cross-sectional configuration of the cooling unit 400 and heat exchanger 500 shown is taken from line II-II.

[0060] As described above, the cooling unit 400 is used to cool the image forming optical system 200. The cooling unit 400, for example, cools reflective polarizers 221R, 221G, and 221B. Figure 3 As shown, the cooling unit 400 includes, for example, three fans 410, 420 and 430.

[0061] The structure of fans 410, 420, and 430 will be described below using fan 410 as an example. Although not shown, fan 410 includes, for example, a main body 411 and a housing 412. The main body 411 includes a motor and rotating blades that rotate integrally with the rotor of the motor. The housing 412 houses the main body 411. The housing 412 has an intake 413 on one of a pair of opposing planar portions and an air outlet 414 on a side portion. The air outlet 414 is spatially coupled to, for example, a reflective polarizer 221B. Air drawn in from the intake 413 is sent as cooling air from the air outlet 414 toward the reflective polarizer 221B. As such fans 410, 420, and 430, for example, multi-blade fans or centrifugal fans can be used.

[0062] In this embodiment, the air inlets 413, 423, and 433 of each of the three fans 410, 420, and 430 are arranged directly or indirectly opposite to the heat exchanger 500. Specifically, for example, as Figure 3 As shown, the fan 410 is arranged such that the air inlet 413 faces the surface 511S, on which a plurality of heat sinks 511 included in the heat exchanger 500 are disposed. This allows the heat exchanger 500 to eliminate noise generated when air is drawn in from the air inlet 413.

[0063] For example, such as Figure 3As shown, the fan 420 is arranged to stack above the surface opposite to the surface where the air inlet 413 of the fan 410 is located, such that the air inlet 423 faces the surface 511S, just as with the fan 410. In other words, the air inlet 423 of the fan 420 is positioned facing the surface 511S, and the fan 410 is positioned between the air inlet 423 and the surface 511S. A plurality of heat sinks 511 are disposed on the surface 511S. The air outlet 424 of the fan 420 is spatially coupled to, for example, a reflective polarizer 221G. Air drawn in from the air inlet 423 is sent from the air outlet 424 toward the reflective polarizer 221G as cooling air.

[0064] For example, such as Figure 3 As shown, for example, a pair of opposing planar portions of fan 430 are arranged along the stacking direction (e.g., the Z-axis direction) of fans 410 and 420. The air inlet 433 of fan 430 is provided, for example, on the opposite side of fans 410 and 420. The air inlet 433 is arranged to indirectly face surface 511S via a duct. Multiple heat sinks 511 are provided on surface 511S. The air outlet 434 of fan 430 is spatially coupled, for example, to a reflective polarizer 221R via a duct. Air drawn in from the air inlet 433 is sent as cooling air from the air outlet 434 toward the reflective polarizer 221R.

[0065] Furthermore, in this embodiment, the three fans 410, 420, and 430 are covered within the housing 900 by two housings 910 and 920, for example, as Figure 6 As shown.

[0066] Housing 910 covers three fans 410, 420, and 430, as well as heat exchanger 500. Housing 910 also serves as a component supporting the three fans 410, 420, and 430. The corresponding positions of the three fans 410, 420, and 430 are, for example, fixed by housing 910. In particular, fan 420 is mounted in conjunction with opening 910H. Housing 422 of fan 420 is included in a portion of housing 910. Opening 910H is provided on the upper surface of housing 910 covering the upper region of fan 410. Opening 910H has a shape substantially the same as that of air inlet 423. The three fans 410, 420, and 430, as well as heat exchanger 500, are housed in a substantially sealed space defined by housing 910. This substantially sealed space serves as a conduit connecting each of the three fans 410, 420, and 430 to the space of heat exchanger 500.

[0067] Housing 920 covers three fans 410, 420, and 430, a heat exchanger 500, and an image forming optical system 200. Housing 920 is located outside housing 910. This allows the air inlet 433 of fan 430 to be covered by a double housing (housing 910 and 920). Fan 430 is arranged along the stacking direction of fans 410 and 420.

[0068] The housing 910 further has an opening at a location corresponding to, for example, the image forming unit 220. This connects the space within the housing 910 and the space within the housing 920, allowing air circulation. Specifically, air drawn in from the respective air inlets 413, 423, and 433 of the fans 410, 420, and 430, heated, and sent from the respective air outlets 414, 424, and 434 toward the reflective polarizers 221R, 221G, and 221B, is conveyed through the opening in the housing 910 to the heat exchanger 500. The conveyed air is cooled by a plurality of heat sinks 511 included in the heat exchanger 500. The cooled air is then drawn in again from the respective air inlets 413, 423, and 433 of the fans 410, 420, and 430.

[0069] (1-3. Functions and Effects)

[0070] The projection display device 1 according to this embodiment has fans (fans 410, 420, and 430) and a heat exchanger 500 arranged facing each other. This allows the heat exchanger 500 to eliminate noise generated from the fans 410, 420, and 430. The fans (fans 410, 420, and 430) send cooling air to reflective polarizers 221R, 221G, and 221B of, for example, the image forming optical system 200. This will be described below.

[0071] In recent years, the brightness of projection display devices has increased. Consequently, higher heat is generated in the optical system. As a method for cooling the optical system, as described above, projection display devices have been developed that house and cool the target within a sealed space. However, for example, due to heat from peripheral components such as the light source unit 100, the circulating temperature of the sealed portion of a typical projection display device is easily increased. Increasing the speed of the cooling fan to achieve sufficient cooling efficiency raises concerns about increased noise.

[0072] To address this issue, in this embodiment, fans 410, 420, and 430, along with the heat exchanger 500, are arranged facing each other. Fans 410, 420, and 430 deliver cooling air to, for example, reflective polarizers 221R, 221G, and 221B. Specifically, the corresponding air inlets 413 and 423 of fans 410 and 420 are arranged facing a surface 511S, which is vertically disposed and includes a plurality of heat sinks 511 in the heat exchanger 500. Furthermore, the air inlet 433 of fan 430 is spatially aligned with surface 511S via a duct. This eliminates noise generated by fans 410, 420, and 430 from the heat exchanger 500.

[0073] The heat exchanger 500 thus eliminates noise generated by the fans 410, 420, and 430, because the projection display device 1 according to this embodiment arranges the air inlets 413, 423, and 433 of the fans 410, 420, and 430 directly opposite the surface 511S on which a plurality of heat sinks 511 are mounted. The fans 410, 420, and 430 are the source of noise. This allows for increased quietness while achieving higher brightness.

[0074] Furthermore, in the projection display device 1 according to this embodiment, fans 410, 420, and 430 are covered by two housings, housing 910 and housing 920. Housing 910 houses the cooling unit 400 and the heat exchanger 500. Housing 920 houses the image forming optical system 200, excluding the cooling unit 400 and the heat exchanger 500. In other words, fans 410, 420, and 430 are covered by housings with a substantially sealed double structure. This further improves cooling efficiency and quietness. Additionally, it enhances dustproof performance.

[0075] <2. Variations>

[0076] Although the present technology has been described above with reference to embodiments, it is not limited to the embodiments described above. Various modifications are possible. For example, examples of air inlets (e.g., air inlets 413, 423, and 433) being arranged directly opposite the heat exchanger 500, or opposite the heat exchanger 500 via another fan (e.g., fan 410), or air inlets being coupled to the heat exchanger 500 through a duct space, have been described in the above embodiments, but are not limiting. For example, as... Figure 7 As shown, the fan 440 may be positioned above the heat exchanger 500, for example, along the Z-axis. A duct 911 may be provided, spatially coupling its air inlet 443 to the housing 910. The opening 911H of this duct 911 may be arranged directly opposite the heat exchanger 500. Alternatively, for example, as... Figure 8As shown, the fan 540 can be configured such that the surface opposite to the surface having, for example, the air inlet 453, faces the heat exchanger 500. The opening 912H defined by the side portion of the housing 452 and the housing 910 can be arranged facing the heat exchanger 500. In other words, it is sufficient as long as the air inlets of each fan are spatially aligned with the heat exchanger 500. Even if the air inlets of each fan are not necessarily directly aligned with the heat exchanger 500, effects similar to those of the embodiments described above can be obtained. These openings 911H and 912H each correspond to a specific example of a "second air inlet" according to this disclosure.

[0077] Furthermore, the arrangement and number of components in the optical system illustrated in the above embodiments are merely examples. Each optical system need not include all components. Alternatively, an optical system may include other components.

[0078] Furthermore, as a projection display device according to this disclosure, devices other than the projection display device 1 described above can be configured. For example, an example of using a reflective liquid crystal panel as a spatial modulation element has been described in the above embodiments. However, for example, this technology can be applied to a transmissive 3LCD projection display device that performs light modulation by using, for example, a transmissive liquid crystal panel. Furthermore, the liquid crystal panel is a non-limiting example of a spatial modulation element. For example, a DMD (digital micromirror device) or the like can also be used.

[0079] It should be noted that the effects described in this manual are merely illustrative and are not limited to the descriptions. Other effects may exist.

[0080] This technology can also have the following configuration. According to this technology with the following configuration, the fan and heat exchanger in the cooling unit are arranged facing each other. This allows the heat exchanger to eliminate noise generated by the fan. The fan delivers cooling air to the image forming optical system, which includes spatial modulation elements. Furthermore, quietness is improved. (1)

[0082] A projection display device, comprising:

[0083] Light source unit;

[0084] An image forming optical system includes a spatial modulation element that modulates light emitted from a light source unit;

[0085] The projection optical system projects light from the spatial modulation element;

[0086] The cooling unit includes a fan that directs cooling air to the image forming optical system; and

[0087] A heat exchanger is arranged opposite the fan. (2)

[0089] According to the projection display device of (1), the fan has a pair of flat portions with an air inlet and a side portion with an air outlet, and the flat portion with the air inlet is arranged opposite to the heat exchanger. (3)

[0091] According to the projection display device described in (2), wherein,

[0092] The heat exchanger has a structure in which multiple heat sinks are arranged upright at predetermined intervals, and

[0093] The flat part of the fan with the air inlet is arranged facing the surface on which multiple heat sinks are mounted. (4)

[0095] According to the projection display device described in (1), wherein,

[0096] The fan has a pair of flat portions, one of which has a first air inlet, a side portion having an air outlet, and a duct forming a second air inlet spatially connected to the first air inlet.

[0097] The second air inlet is arranged directly opposite the heat exchanger. (5)

[0099] The projection display device according to (1) further includes a housing surrounding the cooling unit, wherein...

[0100] The fan has a pair of flat portions, one of which has a first air inlet, a side portion having an air outlet, and a second air inlet defined by the side portion and the housing.

[0101] The second air inlet is arranged directly opposite the heat exchanger. (6)

[0103] According to the projection display device described in (4) or (5), wherein,

[0104] The heat exchanger has a structure with multiple heat sinks arranged at predetermined intervals, and

[0105] The second air inlet of the fan is arranged directly opposite the surface on which the plurality of heat sinks are mounted. (7)

[0107] The projection display device according to any one of (1) to (6) further includes a housing with a dual structure that surrounds the cooling unit. (8)

[0109] The projection display device according to any one of (1) to (6), wherein,

[0110] The cooling unit includes a first fan and a second fan, and

[0111] The first fan and the second fan are stacked on top of the heat exchanger. (9)

[0113] According to the projection display device described in (8), wherein,

[0114] The air inlet of the first fan faces the heat exchanger, and

[0115] The air inlet of the second fan faces the heat exchanger through the first fan. (10)

[0117] According to the projection display device described in (8) or (9), wherein,

[0118] The cooling unit further includes a third fan, and

[0119] The third fan is arranged along the stacking direction of the first fan and the second fan. (11)

[0121] According to the projection display device described in (10), the air inlet of the third fan is arranged on the opposite side of the stacked first fan and second fan. (12)

[0123] According to the projection display device of (10) or (11), the air inlet of the third fan is spatially connected to the heat exchanger via a pipe. (13)

[0125] The projection display device according to any one of (10) to (12) further includes a housing with a dual structure, the housing surrounding the cooling unit, wherein

[0126] The housing includes:

[0127] A first housing surrounds the first fan, the second fan, and the third fan, and

[0128] The second housing, together with the first fan, the second fan, and the third fan, surrounds the image forming optical system. (14)

[0130] The projection display device according to any one of (1) to (13), wherein,

[0131] The image forming optical system includes a polarizer, and

[0132] Cooling air is directed towards the polarizer. (15)

[0134] The projection display device according to any one of (1) to (14) wherein the fan includes a multi-blade fan or a centrifugal fan.

[0135] This application claims priority based on Japanese Patent Application No. 2020-088344, filed with the Japan Patent Office on May 20, 2020, the entire contents of which are incorporated herein by reference.

[0136] Those skilled in the art will understand that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors, as long as they are within the scope of the appended claims or their equivalents.

Claims

1. A projection display device, comprising: Light source unit; An image forming optical system includes a spatial modulation element that modulates light emitted from the light source unit; The projection optical system projects light from the spatial modulation element; The cooling unit includes a first fan and a second fan that deliver cooling air to the image forming optical system; as well as A heat exchanger is arranged facing the first fan and the second fan; The first fan and the second fan are stacked on top of the heat exchanger. The air inlet of the first fan faces the heat exchanger, and The air inlet of the second fan faces the heat exchanger through the first fan.

2. The projection display device according to claim 1, wherein, The first fan and the second fan each have a pair of flat portions with an air inlet and a side portion with an air outlet, and the flat portion with the air inlet is arranged facing the heat exchanger.

3. The projection display device according to claim 2, wherein, The heat exchanger has a structure in which multiple heat sinks are arranged upright at predetermined intervals, and The flat portion of each of the first fan and the second fan, which has the air inlet, is arranged facing the surface on which multiple heat sinks are mounted.

4. The projection display device according to claim 1, wherein, The first fan and the second fan each have a pair of flat portions with a first air inlet, a side portion with an air outlet, and a duct forming a second air inlet spatially connected to the first air inlet. The second air inlet is arranged directly opposite the heat exchanger.

5. The projection display device according to claim 1, further comprising: Housing, surrounding the cooling unit, wherein The first fan and the second fan each have a pair of flat portions with a first air inlet, a side portion with an air outlet, and a second air inlet defined by the side portion and the housing. The second air inlet is arranged directly opposite the heat exchanger.

6. The projection display device according to claim 4, wherein, The heat exchanger has a structure in which multiple heat sinks are arranged upright at predetermined intervals, and The second air inlet of the fan is arranged directly opposite the surface on which the plurality of heat sinks are mounted.

7. The projection display device according to claim 1, further comprising: The housing has a dual structure, and the housing surrounds the cooling unit.

8. The projection display device according to claim 1, wherein, The cooling unit further includes a third fan, and The third fan is arranged along the stacking direction of the first fan and the second fan.

9. The projection display device according to claim 8, wherein, The air inlet of the third fan is arranged on the opposite side of the stacked first and second fans.

10. The projection display device according to claim 8, wherein, The air inlet of the third fan is spatially connected to the heat exchanger via a pipe.

11. The projection display device according to claim 8, further comprising: The housing has a dual structure, wherein the housing surrounds the cooling unit, wherein The housing includes: A first housing surrounds the first fan, the second fan, and the third fan, and The second housing, together with the first fan, the second fan, and the third fan, surrounds the image forming optical system.

12. The projection display device according to claim 1, wherein, The image forming optical system includes a polarizer, and Cooling air is delivered to the polarizer.

13. The projection display device according to claim 1, wherein, The first fan and the second fan respectively include a multi-blade fan or a centrifugal fan.

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