Projection device

Abstract

A cooling fan is used to cool the projection device well. The projection device (10) comprises: an optical device (60); a control circuit substrate (300) arranged on the upper side of the optical device (60); a cooling fan (280) arranged near the rear surface air intake portion (264) of the housing (250) on the side opposite to the projection direction, and having an upper surface air intake port (280a) for taking air in from the upper surface and a lower surface air intake port (280b) for taking air in from the lower surface; and heat sinks (a first heat sink (281) and a second heat sink (282)) arranged corresponding to the ejection port (280c) of the cooling fan (280) and connected to the optical device (60); the flow path resistance on the lower surface air intake port (280b) side is smaller than the flow path resistance on the upper surface air intake port (280a) side.

Description

Technical Field

[0001] The present invention relates to a projection device. Background Art

[0002] Previously, technologies have been proposed for cooling the light source and control substrate of a projection device that projects an image formed by a micromirror display element called a DMD (digital micromirror device) and a liquid crystal panel onto a screen. For example, the projection device disclosed in Patent Document 1 includes a partition that separates a first area from a second area. The first area includes an optical unit including a light source and a transmissive liquid crystal panel, while the second area is equipped with a power supply and a control substrate. A cooling fan is provided in each area, and external air is drawn in through a dust filter. The dust resistance of the second area is less severe than that of the first area, thereby improving the cooling efficiency of the second area.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2016-80957 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] When aiming to make a projection device compact, multiple heat-generating components are densely packed inside the projection device housing. Consequently, even if the compact housing is partitioned into zones using a conventional divider, there may be areas where there is no space for the divider, or the divider itself has a complex shape, making it difficult to divide the first and second zones. Furthermore, if a single cooling fan is used to cool both the first and second zones in order to miniaturize the projection device, it may be difficult to adequately cool all the components inside the projection device housing.

[0008] An object of the present invention is to satisfactorily cool a projection device using a single cooling fan.

[0009] Means used to solve problems

[0010] The projection device of the present invention is characterized in that it comprises: an optical device; a control circuit substrate arranged on the upper side of the above-mentioned optical device; a cooling fan arranged near the rear surface air intake portion of the housing on the side opposite to the projection direction, and having an upper surface air intake port for sucking air from the upper surface and a lower surface air intake port for sucking air from the lower surface; and a heat sink provided corresponding to the ejection port of the above-mentioned cooling fan and connected to the above-mentioned optical device; the flow path resistance on the side of the above-mentioned lower surface air intake port is smaller than the flow path resistance on the side of the above-mentioned upper surface air intake port.

[0011] Effects of the Invention

[0012] According to the present invention, the projection device can be cooled satisfactorily by using one cooling fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a front perspective view showing the appearance of a projection device according to an embodiment of the present invention.

[0014] Figure 2 It is a rear perspective view showing the appearance of a projection device according to an embodiment of the present invention.

[0015] Figure 3A The projection device according to the embodiment of the present invention is shown in an exploded perspective view as seen from above.

[0016] Figure 3B The projection device according to the embodiment of the present invention is shown in an exploded perspective view as seen from below.

[0017] Figure 4 This is an exploded perspective view of the optical device in the projection device according to the embodiment of the present invention as viewed from the bottom.

[0018] Figure 5A It is a plan view showing a cooling fan of the projection device according to the embodiment of the present invention.

[0019] Figure 5B It is a bottom view showing a cooling fan of the projection device according to the embodiment of the present invention.

[0020] Figure 6 The interior of the optical housing of the projection device according to the embodiment of the present invention is omitted and represented by mesh hatching. Figure 1 VI-VI sectional view.

[0021] Figure 7 This is a perspective view showing a heat sink for an IC chip on a substrate of a projection device according to an embodiment of the present invention.

[0022] Figure 8 The interior of the optical housing of the projection device according to the embodiment of the present invention is omitted and represented by mesh hatching. Figure 1 Sectional view VIII-VIII of .

[0023] Figure 9 The interior of the optical housing of the projection device according to the embodiment of the present invention is omitted and represented by mesh hatching. Figure 1 IX-IX sectional view.

[0024] Figure 10 This is a diagram showing a functional circuit block of a projection device according to an embodiment of the present invention.

[0025] Figure 11It is a schematic plan view showing the internal structure of the projection device according to the embodiment of the present invention.

[0026] Figure 12 It is a schematic plan view showing the flow of cooling air in the projection device according to the embodiment of the present invention.

[0027] Figure 13 The present invention is an embodiment of the housing and power circuit board of the projection device. Figure 11 Sectional view XIII-XIII of . DETAILED DESCRIPTION

[0028] Hereinafter, the embodiments of the present invention will be described. Figure 1 、 Figure 2 As shown, the projection device 10 includes a housing 250, which is formed into a compact shape and has six surfaces as outer peripheral surfaces (upper surface 250a, lower surface 250b, left side 250c (second side), right side 250d (first side), front surface 250e, and rear surface 250f) (in addition, the first side and the second side are opposite each other), and is in the shape of a roughly long rectangular box with the left-right direction as the longitudinal direction. The projection device 10 has a projection port 11 on the front surface 250e side. The projection device 10 emits projection light from the projection port 11. In the following description, left and right of the projection device 10 refers to the left and right directions relative to the projection direction of the projection port 11, and front and back refer to the front and back directions relative to the direction of travel of the projection light of the projection device 10.

[0029] The housing 250 includes an upper housing 251, a lower housing 252, a left side panel 253, a front side panel 254, and a rear side panel 255. The upper housing 251 is also Figure 3A 、 Figure 3B As shown, the housing 251 includes an upper panel portion 251a having an upper surface 250a and a right upper panel portion 251b having a surface that forms a portion of the upper side of the right side 250d. The lower housing 252 includes a lower panel portion 252a having a lower surface 250b and a right lower panel portion 252b having a surface that forms a portion of the lower side of the right side 250d. The connection between the upper panel portion 251a and the right upper panel portion 251b and the connection between the lower panel portion 252a and the right lower panel portion 252b are curved into an R-shape. The left side panel 253, the front panel 254, and the rear panel 255 are formed into outer peripheral plates together with the upper panel portion 251a and the right upper panel portion 251b of the upper housing 251 and the lower panel portion 252a and the right lower panel portion 252b of the lower housing 252.

[0030] A power plug 15 is provided on the rear lower side of the right side 250d (behind the right lower panel 252b). The lower housing 252 is manufactured by die-casting using a metal material such as a magnesium alloy or aluminum alloy. The upper housing 251 and the front, rear, and left panels are molded from a resin material.

[0031] A projection image adjustment unit 12 having one or more knobs is provided on the upper surface of the upper housing 251 at a position corresponding to the projection port 11. By operating the knobs of the projection image adjustment unit 12, the position of the working lens of the projection optical system is adjusted, and the size and focus of the projected image are adjusted. In addition, a key / indicator unit 37 is provided on the upper surface of the rear side of the upper housing 251. The key / indicator unit 37 is provided with a power switch key and a power indicator for reporting whether the power is on or off, a projection switch key for switching the projection on or off, an optical device 60, a display element 51 (in Figure 11 Keys and indicators for making various settings, such as an overheat indicator that reports when the control circuit, etc. overheats (described later) or an overheat indicator.

[0032] The front panel 254, which is longer in the left-right direction, extends to the left front corner 250g of the housing 250, and the left front corner 250g is angled R-shaped. Similarly, the rear panel 255, which is longer in the left-right direction, extends to the left rear corner 250h of the housing 250, and the left rear corner 250h is angled R-shaped. The left side panel 253 is provided between the front panel 254 extending to the left front corner 250g and the rear panel 255 extending to the left rear corner 250h.

[0033] The left side panel 253, the front side panel 254, and the rear side panel 255 are continuously provided with transverse ribs 256 at approximately the center in the vertical direction of each panel. The upper and lower sides of the transverse ribs 256 of each panel are generally horizontally long and lattice-shaped. The left side panel 253, the front side panel 254, and the rear side panel 255 are topped with the transverse ribs 256, and the upper and lower sides of the transverse ribs 256 are inclined toward the interior of the housing 250.

[0034] An air intake section 261 is provided in the area extending from the approximate center to the rear of the left side panel 253. This section includes a plurality of narrow, horizontally long air intake holes arranged in a horizontally long grid pattern. Air intake section 261 has a plurality of narrow, horizontally long air intake holes arranged along the roughly horizontally long grid pattern. A speaker section 48a is provided on the front side of the left side panel 253, with a portion of the horizontally long grid pattern open. Speaker 48 is provided within speaker section 48a. An input / output connector section 21 for image signals is provided on the rear side of the left side panel 253.

[0035] The front panel 254 has a designated area on the right end as an exhaust section 260, and a designated area approximately in the center as an intake section 262. The intake section 262 includes a right intake section 262a and a left intake section 262b. The front panel 254 has a projection port opening 254a near its left front corner 250g, facing the projection port 11. The right front corner 250i, where the front panel 254 connects to the right upper panel section 251b and the right lower panel section 252b of the right side 250d, forms a right angle in plan view.

[0036] The exhaust section 260 is provided with inclined ribs 254b on the upper and lower sides, radially extending from the right end of the transverse rib 256. Furthermore, two longitudinal ribs 254c are provided in the exhaust section 260, spaced apart at predetermined intervals, above and below the transverse rib 256, respectively, at a position closer to the center of the inclined rib 254b. The exhaust section 260 also includes a double, horizontally long, U-shaped rib 254d, positioned between the inclined rib 254b and the longitudinal rib 254c. The opening of the exhaust section 260 is larger than that of the intake sections 261, 262, 263, and 264.

[0037] The inclined ribs 254b and the longitudinal ribs 254c are also as shown in FIG. Figure 11 As shown, the front panel 254 is tilted so that the exhaust direction is rightward. The area other than the exhaust portion 260 and the projection port opening 254a of the front panel 254 is in a substantially horizontally long grid shape.

[0038] The rear panel 255 is provided with an output plug 14 for audio equipment on the upper left side. The right end of the rear panel 255 is a grid-like, roughly U-shaped grid that imitates the horizontally long grid of other parts. From the left side to the approximately center of the rear panel 255, there is an air intake portion 263 with relatively thin horizontally long air intake holes in the shape of a horizontally long grid. The right side of the rear panel 255 is also provided with an air intake portion 264 (rear surface air intake portion) with air intake holes (relatively thin horizontally long air intake holes and relatively thin, roughly U-shaped air intake holes). The right rear corner 250j of the rear panel 255, which connects to the upper right panel portion 251b and the lower right panel portion 252b of the right side 250d, is at a right angle in plan view.

[0039] Thus, the projection device 10 includes an intake and exhaust unit including intake units 261 to 264 having a plurality of intake holes or exhaust holes and an exhaust unit 260. In other words, the intake and exhaust unit of the projection device 10 includes a plurality of intake and exhaust holes.

[0040] Next, the housing form of the housing 250 of the projection device 10 will be described. Figure 3A 、 Figure 3BAs shown, the housing 250 of the projection device 10 houses an optical housing 61, a control circuit board 300, a cooling fan 280, a first heat sink 281, and a second heat sink 282. The optical housing 61 houses various optical components of the optical device 60, such as light sources, lenses, and mirrors, and is equipped with a lens barrel 225.

[0041] Optical shell 61 Figure 3B and Figure 4 As shown, an opening portion 61a is provided on the lower side (the lower surface 250b side of the housing 250, the lower side in the thickness direction of the housing 250). In the opening portion 61a, a cover component 62 is fixed with a plurality of bolts together with a sealing component not shown in the figure for dust prevention. The sealing component is arranged along the edge of the opening portion 61a. The opening portion 61a is covered by the cover component 62, and the interior of the optical housing 61 becomes a closed space. When the optical device 60 is manufactured, optical components such as lenses and reflectors and light sources are installed into the interior of the optical housing 61 through the opening portion 61a. Here, Figure 4 The figure shows an exploded perspective view of the optical housing 61 , in which optical components such as a condenser lens housed therein are omitted and viewed from the bottom.

[0042] Furthermore, a portion of the fluorescent plate assembly 100, described later, protrudes through an opening in the upper surface of the optical housing 61 and is covered by a cover 65. Compared to the cover member 62, the mounting range of the cover 65 is limited and smaller. Therefore, dust protection measures such as sealing members can be easily implemented for the opening covered by the cover 65.

[0043] like Figure 3A As shown, a control circuit board 300 serving as a main board is provided on the upper surface of the optical housing 61. The control circuit board 300 is screwed to bosses and brackets that are vertically provided from the upper surface of the optical housing 61 and the inner side surface of the lower panel portion 252a of the lower housing 252, and is fixedly arranged on the upper side of the housing 250. Figure 11 As shown, a blower-type cooling fan 280 using a Sirocco fan is disposed on the right rear side of the optical housing 61 (in other words, near the air intake portion 264 of the housing 250 on the side opposite to the projection direction). The projection device 10 has only one cooling fan 280, not multiple cooling fans.

[0044] On the upper surface of the cooling fan 280, as shown Figure 5AAs shown, an upper surface air intake port 280a for sucking air from the upper surface of the cooling fan 280 is provided. The upper surface air intake port 280a is composed of three roughly arc-shaped openings. On the other hand, a lower surface air intake port 280b is provided on the lower surface of the cooling fan 280. The lower surface air intake port 280b is composed of one circular opening. The area of the lower surface air intake port 280b is larger than the area of the upper surface air intake port 280a (the total area of the three roughly arc-shaped openings). The cooling fan 280 sucks air from the upper surface air intake port 280a and the lower surface air intake port 280b, and exhausts air from the ejection port 280c, and the opening direction of the ejection port 280c is orthogonal to the opening direction of the upper surface air intake port 280a and the lower surface air intake port 280b.

[0045] In addition, if Figure 6 As shown, the cooling fan 280 is provided near the right side surface 250d (the upper right panel portion 251b and the lower right panel portion 252b). Here, the right side surface 250d is not provided with an intake and exhaust hole, and the external air is not taken in from the right side surface 250d. In addition, the cooling fan 280 is arranged on the upper side of the thickness direction of the outer shell 250. That is, the space on the lower side of the cooling fan 280 in the outer shell 250 (the lower side space Y surrounded by a double-dotted line and shaded on the inside) is larger than the space on the upper side of the cooling fan 280 in the outer shell 250 (the upper side space X surrounded by a double-dotted line and shaded on the inside). Therefore, the flow path resistance on the side of the lower surface intake port 280b is smaller than the flow path resistance on the side of the upper surface intake port 280a. In addition, Figure 6 In the figure, components such as the focusing lens and the reflecting mirror inside the optical device 60 are omitted, and the interior is represented by mesh hatching.

[0046] Back to Figure 3A In front of the cooling fan 280, heat sinks (first heat sink 181 and second heat sink 282) connected to the optical device 60 are provided corresponding to the outlet 280c of the cooling fan 280. Specifically, the second heat sink 282 is provided in front of the outlet 280c of the cooling fan 280, and the first heat sink 281 is provided in front of the second heat sink 282. In addition, the power supply circuit board 310 (see FIG. 1 ) is arranged directly below the lower side of the cooling fan 280 (between the cooling fan 280 and the lower housing 252, i.e., in the lower space Y). Figure 6 ). Furthermore, a third heat sink 283 connected to the optical device 60 is provided approximately at the center rear side of the optical housing 61. The third heat sink 283 has a plurality of fins. A concave grip portion 270 is provided at the front center of the lower surface 250b of the lower housing 252.

[0047] On the control circuit substrate 300, an IC heat sink 285 for cooling the IC chip 301 provided on the lower surface of the control circuit substrate 300 is mounted on the left end of the front side. Figure 7As shown, the IC heat sink 285 is formed of a metal plate and includes a flat plate-shaped abutment plate 285a disposed in contact with the IC chip 301, a comb-shaped first heat sink 285b extending vertically downward from the abutment plate 285a, and a second heat sink 285c adjacent to the first heat sink 285b at right angles and inclined inward. The IC heat sink 285 is mounted at a corner of the optical housing 61, with the first heat sink 285b facing the front surface 250e. Thus, the first and second heat sinks 285b and 285c are arranged along the outer periphery of the optical housing 61.

[0048] Also like Figure 8 、 Figure 9 and Figure 6 As shown, a gap is provided between the housing 250 of the projection device 10 and the optical housing 61 (optical device 60). Furthermore, the region including the gap between the upper surface of the optical housing 61 (optical device 60) and the lower surface of the upper panel portion 251a of the upper housing 251 of the housing 250 (the region on the upper side surrounded by the double-dashed line with a shadow on the inside) is used as the first air flow path 91 for the circulation of cooling air. Furthermore, the region including the gap between the lower surface (the lower surface of the cover part 62) of the optical housing 61 (optical device 60) and the upper surface of the lower panel portion 252a of the lower housing 252 of the housing 250 (the region on the lower side surrounded by the double-dashed line with a shadow on the inside) is used as the second air flow path 92 for the circulation of cooling air. In addition, in Figure 8 、 Figure 9 In the figure, components such as a focusing lens and a reflecting mirror inside the optical device 60 are omitted, and the interior of the closed space is represented by mesh hatching.

[0049] The gap between the optical housing 61 and the housing 250 in the first air flow passage 91 is larger than the gap between the optical housing 61 and the housing 250 in the second air flow passage 92. In other words, Figure 8 、 Figure 9 As shown in the longitudinal section of FIG, the cross-sectional area of the first air flow passage 91 is larger than the cross-sectional area of the second air flow passage 92. In other words, the first air flow passage 91 is wider than the second air flow passage 92. Therefore, the flow rate of the cooling air in the first air flow passage 91 is larger than the flow rate of the cooling air in the second air flow passage 92. In other words, the flow resistance of the first air flow passage 91 is smaller than the flow resistance of the second air flow passage 92. Furthermore, the cooling air in the second air flow passage 92 flows on the cover component 62 side of the optical housing 61.

[0050] Figure 10This is a functional circuit block diagram of the projection device 10. The projection device control unit includes a CPU including the image conversion unit 23 and the control unit 38, a front-end unit including the input / output interface 22, and a formatter unit including the display encoder 24 and the display driver 26. Image signals of various standards input from the input / output connector 21 are converted by the image conversion unit 23 via the input / output interface 22 and the system bus SB into image signals in a predetermined format suitable for display. The signals are then output to the display encoder 24.

[0051] Furthermore, the display encoder 24 expands the input image signal and stores it in the video RAM 25 , then generates a video signal based on the stored content of the video RAM 25 and outputs it to the display driver 26 .

[0052] The display driver 26 drives the display element 51, which serves as a spatial light modulator (SOM), at an appropriate frame rate in response to the image signal output from the display encoder 24. The projection device 10 directs a light beam emitted from the optical device 60 toward the display element 51 via a light guide optical system. This light reflects off the display element 51 to form an optical image, which is then projected onto a projection object such as a screen (not shown) via the projection-side optical system 220. Furthermore, the movable lens group 235 of the projection-side optical system 220 can be driven for zoom and focus adjustments by a lens motor 45.

[0053] The image compression / expansion unit 31 also performs data compression on the luminance and color difference signals of an image signal through processes such as ADCT and Huffman coding, and then sequentially writes the data to a removable recording medium, a memory card 32. Furthermore, in playback mode, the image compression / expansion unit 31 reads the image data recorded on the memory card 32, expands each frame of image data constituting a series of moving images, and outputs the data to the display encoder 24 via the image conversion unit 23. This allows the image compression / expansion unit 31 to output moving images, etc., based on the image data stored on the memory card 32.

[0054] The control unit 38 controls the operation of each circuit in the projection device 10 and is composed of a CPU, a ROM that fixedly stores operation programs for various settings, and a RAM used as a work memory.

[0055] The key / indicator unit 37 is composed of a main key and an indicator provided on the housing. Operation signals from the key / indicator unit 37 are directly sent to the control unit 38. Furthermore, key operation signals from the remote control are received by the Ir receiver 35, demodulated into a coded signal by the Ir processor 36, and output to the control unit 38.

[0056] The control unit 38 is connected to the audio processing unit 47 via the system bus SB. The audio processing unit 47 includes an audio source circuit such as a PCM audio source, and converts audio data into analog form in the projection mode and the playback mode, and drives the speaker 48 to amplify the sound.

[0057] The control unit 38 controls the light source control circuit 41. The light source control circuit 41 independently controls the operation of the excitation light irradiation device of the optical device 60 so that light of a predetermined wavelength band required for image generation is emitted from the optical device 60.

[0058] Furthermore, the control unit 38 causes the cooling fan drive control circuit 43 to detect temperatures using a plurality of temperature sensors provided in the optical device 60 and the like, and controls the rotation speed of the cooling fan 280 based on the results of the temperature detection. Furthermore, the control unit 38 causes the cooling fan drive control circuit 43 to control, for example, to continue rotating the cooling fan 280 even after the power of the projection device 10 main body is turned off, or to turn off the power of the projection device 10 main body based on the results of the temperature detection by the temperature sensors, using a timer or the like.

[0059] Then, based on Figure 11 The internal structure of the optical device 60 will be described. Figure 11 The first heat sink 281 and the second heat sink 282 are shown in cross-section to illustrate the plurality of heat dissipation fins included in the first heat sink 281 and the second heat sink 282 .

[0060] The optical device 60 includes a red light source device 120, which serves as a light source for red wavelength band light; a green light source device 80, which serves as a light source for green wavelength band light; and an excitation light irradiation device 70, which serves as a light source for blue wavelength band light and also serves as an excitation light source. The green light source device 80 is composed of the excitation light irradiation device 70 and the fluorescent plate device 100. The optical device 60 includes a light guide optical system 140. The light guide optical system 140 combines the light beams of the green wavelength band, the blue wavelength band, and the red wavelength band, guiding the light beams of each color band along the same optical path.

[0061] The excitation light irradiation device 70 is arranged on the right rear side of the optical shell 61. The excitation light irradiation device 70 has a plurality of semiconductor light emitting elements arranged in a manner so that the optical axis is parallel to the rear panel 255. The semiconductor light emitting elements of this embodiment are a plurality of blue laser diodes 71 that emit light in the blue wavelength band. On each blue laser diode 71, a collimating lens 73 is integrally mounted to improve the directivity of the emitted light from the blue laser diode 71 and convert it into parallel light. These blue laser diodes 71 are fixed to a retaining plate 74. On the retaining plate 74, there are 8 blue laser diodes 71 in 2 rows and 4 columns.

[0062] The excitation light irradiation device 70 also includes a reflector group 76, a condenser lens 77, and a diffuser plate 78. The reflector group 76 shifts the optical axis of the light emitted from each blue laser diode 71, emitted from the right side to the left side, by approximately 90 degrees from the rear side to the front side, that is, toward the condenser lens 77. The diffuser plate 78, disposed in front of the condenser lens 77, diffuses the light emitted from each blue laser diode 71, which has been reflected by the reflector group 76 and condensed by the condenser lens 77, at a predetermined diffusion angle.

[0063] The excitation light irradiation device 70 is connected to a heat pipe 79 on the back side of the retaining plate 74. The heat pipe 79 is connected to the first heat sink 281. The plurality of blue laser diodes 71, which serve as lasers, are cooled by the first heat sink 281. The front ends of the plurality of heat dissipation fins 281a on the left side of the first heat sink 281 are inclined, similar to the inclined ribs 254b and longitudinal ribs 254c in the exhaust portion 260.

[0064] The red light source device 120 is provided in front of the excitation light irradiation device 70 in the optical housing 61. The red light source device 120 includes a red light source 121 arranged so that its optical axis is parallel to the light beam of the blue laser diode 71, and a focusing lens group 125 for focusing the light emitted from the red light source 121. The red light source 121 is a red light emitting diode, which is a semiconductor light emitting element, that emits light in the red wavelength band. The red light source device 120 is arranged so that the optical axis of the red light in the red wavelength band emitted by the red light source device 120 intersects the optical axis of the green light in the green wavelength band emitted from the fluorescent plate 101. The back side of the red light source device 120 is connected to a heat pipe 129. The heat pipe 129 is connected to the second heat sink 282. The red light source 121, which is a light emitting diode, is cooled by the second heat sink 282.

[0065] The fluorescent plate device 100 constituting the green light source device 80 includes a fluorescent plate 101, a motor 110, and a focusing lens group 117 on the incident side. The fluorescent plate 101 is a fluorescent wheel arranged so as to be perpendicular to the optical axis of the light emitted from the excitation light irradiation device 70. The fluorescent plate 101 is rotationally driven by the motor 110. The focusing lens group 117 focuses the beam of excitation light emitted from the excitation light irradiation device 70 onto the fluorescent plate 101.

[0066] Although not shown, fluorescent plate 101 is circumferentially arranged with a fluorescent light-emitting region and a diffuse transmission region. The fluorescent light-emitting region receives blue wavelength light emitted from blue laser diode 71 as excitation light and emits green-band fluorescence. The diffuse transmission region diffuses and transmits the light emitted from blue laser diode 71. The diffused transmission light is emitted as blue wavelength light from optical device 60.

[0067] The light guide optical system 140 includes a first dichroic mirror 141, a first reflecting mirror 143, a condensing lens 146, a second dichroic mirror 148, a condensing lens 149, a second reflecting mirror 145, and a condensing lens 147. The first dichroic mirror 141 is positioned at a location where the blue light emitted from the excitation light irradiation device 70, the green light emitted from the fluorescent plate 101, and the red light emitted from the red light source device 120 intersect. The first dichroic mirror 141 transmits the blue and red light and reflects the green light. The optical axis of the green light reflected by the first dichroic mirror 141 is shifted 90 degrees toward the left side panel 253 of the condensing lens 149. Consequently, the optical axis of the red light transmitted through the first dichroic mirror 141 coincides with the optical axis of the green light reflected by the first dichroic mirror 141.

[0068] Condensing lens 149 is positioned to the left of first dichroic mirror 141. Red light passing through first dichroic mirror 141 and green light reflected by first dichroic mirror 141 are both incident on condensing lens 149. Second dichroic mirror 148 is positioned to the left of condensing lens 149 and behind condensing lens 147. Second dichroic mirror 148 reflects red and green light while transmitting blue light. Consequently, the red and green light focused by condensing lens 149 are reflected by second dichroic mirror 148 and transformed 90 degrees toward the rear. Condensing lens 173 is positioned behind second dichroic mirror 148. The red and green light reflected by second dichroic mirror 148 are incident on condensing lens 173.

[0069] The first reflector 143 is positioned on the optical axis of the blue light band that has passed through the fluorescent plate 101. The first reflector 143 reflects the blue light band, shifting its optical axis 90 degrees to the left. A condenser lens 146 is positioned to the left of the first reflector 143. Furthermore, the second reflector 145 is positioned to the left of the condenser lens 146. The second reflector 145 shifts the optical axis of the blue light band, which has been reflected by the first reflector 143 and focused by the condenser lens 146, 90 degrees to the rear. A condenser lens 147 is positioned behind the second reflector 145. The blue light band reflected by the second reflector 145 passes through the condenser lens 147, transmits through the second dichroic mirror 148, and enters the condenser lens 173. In this way, the red, green, and blue light bands guided by the light guide optical system 140 are guided along the same optical path of the light source side optical system 170.

[0070] The light source side optical system 170 includes a condenser lens 173, an optical axis conversion mirror 179, a microlens array 175, a condenser lens 183, an illumination mirror 185, and a condenser lens 195. Furthermore, the condenser lens 195 is also part of the projection side optical system 220 because it emits image light emitted from the display element 51 disposed behind the condenser lens 195.

[0071] Each light beam emitted from the condenser lens 173 is reflected approximately to the left by the optical axis conversion mirror 179 disposed on the rear side of the condenser lens 173. Each light beam reflected by the optical axis conversion mirror 179 is converted into a light beam with a uniform intensity distribution by the microlens array 175. The light beam is then incident on the illumination mirror 185 via the condenser lens 183 and reflected there. Each light beam reflected by the illumination mirror 185 is then illuminated at a predetermined angle by the condenser mirror 195 onto the display element 51. Furthermore, the display element 51 is connected to a heat pipe 59 on its rear side. The heat pipe 59 is connected to the third heat sink 283. The display element 51, which serves as a DMD, is cooled by the third heat sink 283.

[0072] The light beam as the light source light irradiated onto the image forming surface of the display element 51 by the light source side optical system 170 is reflected by the image forming surface of the display element 51 and projected onto the screen as projection light via the projection side optical system 220. The projection side optical system 220 includes a condenser lens 195 and a lens barrel 225. The lens barrel 225 includes a movable lens group 235 and a fixed lens group.

[0073] With this configuration of the projection device 10, if the fluorescent plate 101 is rotated and light is emitted from the excitation light irradiation device 70 and the red light source device 120 at different timings, light in the red, green, and blue wavelength bands is incident on the condenser lens 173 of the light source side optical system 170 via the light guide optical system 140, and then on the display element 51 via the light source side optical system 170. Thus, the display element 51 of the projection device 10, i.e., the DMD, displays light of each color in a time-division manner according to data, thereby projecting a color image onto a screen from the projection port 11.

[0074] When the projection device 10 is in use, air is drawn into the upper and lower intake ports 280a, 280b of the cooling fan 280 from the front surface 250e, the left side 250c, and the rear surface 250f according to the operation of the cooling fan 280, and is discharged to the outside from the exhaust portion 260 via the first and second heat sinks 281, 282. Figure 12As shown, external air is drawn into the cooling fan 280 through the air intake sections 261, 262, 263, and 264. At this time, the external air from the air intake sections 261, 262, and 263 facing the first and second air flow passages 91 and 92 flows more through the first air flow passage 91, which has a larger flow passage cross-sectional area (wider flow passage, lower flow resistance), while the flow rate of external air flowing through the second air flow passage 92 is smaller. Consequently, less external air flows through the second air flow passage 92 on the cover member 62 side of the optical housing 61, thereby reducing the intrusion of dust into the interior of the optical housing 61 through the opening 61a of the optical housing 61, which is covered by the cover member 62.

[0075] Furthermore, since the amount of outside air flowing through the second air flow passage 92 is reduced as described above, thereby reducing the intrusion of dust into the optical housing 61, the projection device 10 does not include dust-proof filters in the air intake sections 261 to 264. This eliminates the need for maintenance such as filter replacement and eliminates downtime caused by filter clogging.

[0076] Furthermore, by making the housing 250 compact, the projector 10 is densely packed with internal components, including heat-generating components such as the first and second heat sinks 281 and 282, the excitation light irradiation device 70 and the red light source device 120, the display element 51, and the control circuit board 300. However, in the projector 10, the cooling fan 280, the first and second heat sinks 281 and 282 are located on the right side 250d, and the air intake portions 261 to 264 are provided on the front surface 250e, the left side 250c, and the rear surface 250f, excluding the right side 250d. By drawing air into the projector 10 from these three surfaces, the internal components can be effectively cooled.

[0077] The following mainly describes the flow of cooling air in the first air flow path 91. External air drawn in from the left air intake portion 262b of the air intake section 262 on the front surface 250e of the projection device 10 primarily cools the IC chip 301 (IC heat sink 285), while the right air intake portion 262a primarily cools the fluorescent panel assembly 100. Furthermore, the IC heat sink 285 is also cooled by the portion of external air drawn in from the left air intake portion 262b of the air intake section 262 that flows along the side of the optical housing 61. After cooling the IC chip 301 (IC heat sink 285) and the fluorescent panel assembly 100, the cooling air from the air intake section 262 subsequently cools the red light source assembly 120.

[0078] On the other hand, the outside air taken in through the air intake section 261 on the left side 250c of the projection device 10 primarily cools the projection optical system 220. Furthermore, the outside air taken in through the air intake section 263 on the rear surface 250f of the projection device 10 directly cools the third heat sink 283 and the display element 51. Furthermore, the cooling air from the air intake section 261 merges with the cooling air from the air intake section 263. This merged cooling air further merges with the cooling air from the air intake section 262, which has cooled the IC chip 301 (IC heat sink 285), the fluorescent plate device 100, and the red light source device 120, to cool the excitation light irradiation device 70.

[0079] The cooling air flowing through the first air flow passage 91 in response to the operation of the cooling fan 280 performs the aforementioned cooling while also cooling the control circuit board 300. Since the control circuit board 300 is positioned approximately in the vertical center of the first air flow passage 91, the cooling air flows approximately evenly above and below the control circuit board 300. Furthermore, external air drawn in from the air intake sections 261, 262, and 263 flows through the second air flow passage 92, cooling the entire lower surface of the optical housing 61.

[0080] After cooling the excitation light irradiation device 70, the cooling air from the first air flow passage 91 is mainly taken into the upper surface air intake port 280a of the cooling fan 280, and the cooling air from the second air flow passage 92 is mainly taken into the lower surface air intake port 280b of the cooling fan 280. On the other hand, the external air from the air intake portion 264 located on the rear surface 250f behind the cooling fan 280 is mainly taken into the lower surface air intake port 280b of the cooling fan 280. At this time, the power supply circuit board 310 arranged directly below the cooling fan 280 is cooled by the external air from the air intake portion 264. In addition, part of the cooling air from the first air flow passage 91 and the cooling air from the second air flow passage 92 is also used to cool the power supply circuit board 310.

[0081] The cooling air drawn into cooling fan 280 is discharged from outlet 280c of cooling fan 280. The cooling air discharged from outlet 280c cools second heat sink 282 located on the side of outlet 280c, then cools first heat sink 281 located on the side of front surface 250e, before being discharged to the outside through exhaust section 260. The exhaust direction of exhaust section 260 is inclined away from the intake direction of adjacent intake section 262 by the inclined ribs 254b and longitudinal ribs 254c of exhaust section 260 and the front end portions of fins 281a of first heat sink 281.

[0082] The projection device 10 exhausts air from an exhaust portion 260 disposed at a single location on the front surface 250e. Therefore, even if the projection device 10 includes a blower-type cooling fan 280, which requires consideration of exhaust resistance, other devices can be placed close to the top, bottom, left, right, and rear sides of the projection device 10. This makes it easier to use the projection device 10 as an assembled device.

[0083] In this way, the outside air (cooling air) drawn in by the air intake sections 261, 262, 263, and 264 in response to the operation of the cooling fan 280 cools the components generating the most heat (IC chip 301, phosphor plate assembly 100, red light source assembly 120, display element 51, and third heat sink 283) starting with the components generating the least heat and then proceeding to the components generating the most heat (excitation light irradiation device 70, power supply circuit board 310, second heat sink 282, and first heat sink 281). Furthermore, taking into account the heat generated by the components, the excitation light irradiation device 70 is positioned downwind of the red light source assembly 120, and the first heat sink 281 is positioned downwind of the second heat sink 282.

[0084] Here, the front panel 254 includes a partition plate 254e that separates the first heat sink 281 from the first and second air flow paths 91 and 92. The partition plate 254e is located at the left end of the exhaust section 260 (i.e., to the left of the first heat sink 281). Furthermore, a plurality of longitudinal rib-like closing plates 258 are provided between the right sides of the first and second heat sinks 281 and 282 and the upper right panel portion 251b of the upper housing 251 and the lower right panel portion 252b of the lower housing 252. The closing plates 258 prevent air exhausted from the exhaust section 260 from being drawn into the right side of the first heat sink 281 and being drawn in by the cooling fan 280.

[0085] In addition, if Figure 13 As shown, a shielding wall 252c is provided in the lower housing 252 near the air intake portion 264. The shielding wall 252c is provided integrally with the lower housing 252 formed by metal die-casting. The shielding wall 252c is provided parallel to the rear panel 255. The shielding wall 252c has a plurality of flow holes 252c1. The positions and shapes of the plurality of flow holes 252c1 are respectively consistent with the air intake holes 264a provided in the rear panel 255 as the air intake portion 264. Specifically, the flow holes 252c1 and the air intake holes 264a are both made into relatively thin horizontally long holes, and the two are arranged in an overlapping manner when viewed from the front (viewing the flat rear panel 255 from the flat side (front and rear direction of the projection device 10)).

[0086] Shielding wall 252c reduces the effect of static electricity or electromagnetic waves from outside the projection device 10 on the power circuit board 310, even when the power circuit board 310 is positioned near the plurality of air intake holes 264a. Furthermore, since flow holes 252c1 and air intake holes 264a are aligned, shielding wall 252c does not prevent external air from flowing into the air intake section 264.

[0087] While the embodiments of the present invention have been described above, the present invention is not limited to these embodiments and can be implemented with appropriate modifications. For example, in this embodiment, the first air flow passage 91 is provided on the upper side of the projection device 10, and the second air flow passage 92 is provided on the lower side. However, this is not limiting. For example, if the opening 61a of the optical housing 61 is provided on the upper surface side and the cover member 62 is provided on the upper surface side of the optical housing 61, the second air flow passage 92 may be provided on the upper side of the projection device 10, and the first air flow passage 91 may be provided on the lower side. Furthermore, the shielding wall 252c may be provided separately from the lower housing 252. Alternatively, a configuration may be employed in which the cooling fan 280 is positioned in front of the first heat sink 281, and air is drawn in from the first air flow passage 91 and the second air flow passage 92 by the cooling fan 280 to cool the second heat sink 282 and the first heat sink 281, and the air is discharged directly from the cooling fan 280 through the exhaust unit 260 to the outside.

[0088] According to the above embodiment of the present invention, the projection device 10 includes: an optical device 60; a control circuit substrate 300, which is arranged on the upper side of the optical device 60; a cooling fan 280, which is arranged near the rear surface air intake portion, i.e., the air intake portion 264, of the housing 250 on the side opposite to the projection direction, and has an upper surface air intake port 280a for sucking air from the upper surface and a lower surface air intake port 280b for sucking air from the lower surface; and heat sinks (a first heat sink 281 and a second heat sink 282), which are provided corresponding to the ejection port 280c of the cooling fan 280 and are connected to the optical device 60; the flow path resistance on the side of the lower surface air intake port 280b is smaller than the flow path resistance on the side of the upper surface air intake port 280a.

[0089] Thus, the projection device 10 can be cooled well by the single cooling fan 280 by taking in outside air sucked from the air intake portion 264 mainly through the lower surface air intake port 280 b of the cooling fan 280 and taking in air after cooling the control circuit board 300 through the upper surface air intake port 280 a .

[0090] Furthermore, the lower surface air intake port 280b of the cooling fan 280 is larger than the upper surface air intake port 280a. This allows more external air to be taken in from the air intake portion 264 via the lower surface side of the cooling fan 280 where the flow resistance is smaller.

[0091] Furthermore, cooling fan 280 is disposed on the upper side of housing 250 in the thickness direction, and a space Y below cooling fan 280 within housing 250 is larger than a space X above cooling fan 280 within housing 250. This allows for more efficient intake of external air from below cooling fan 280 via air intake portion 264.

[0092] Furthermore, cooling fan 280 is provided near right side 250d, which serves as the first side surface of housing 250. In response to the operation of cooling fan 280, external air is drawn into housing 250 from three surfaces of housing 250: front surface 250e, which is provided with projection opening 11; left side 250c, which serves as the second side surface opposite to the first side surface (right side 250d); and rear surface 250f, which faces front surface 250e. External air is not drawn in from right side 250d. This allows for excellent cooling of the entire control circuit board 300.

[0093] If an air intake portion is provided on the right side 250d where the cooling fan 280 and the heat sinks for the light source (first heat sink 281 and second heat sink 282) are located, the amount of air taken in from the other three sides will decrease, thereby reducing overall cooling efficiency. Therefore, it is preferable not to provide an air intake portion on the right side 250d of the housing 250.

[0094] Furthermore, if an air intake portion is provided on the upper surface 250a of the housing 250, while the excitation light irradiation device 70 having a laser source located close to the cooling fan 280 may be cooled effectively, the amount of air taken in from the other three surfaces will decrease, disrupting the overall cooling balance and reducing the overall cooling efficiency. Therefore, it is preferable not to provide an air intake portion on the upper surface 250a of the housing 250.

[0095] Furthermore, if an air intake portion is provided on the lower surface 250b of the housing 250, a cooling effect can be expected. However, the lower surface 250b side is closer to the installation surface side of the housing 250, and is more easily affected by the user's usage location and usage form than the upper surface 250a side. For example, if the housing 250 is placed on a cushion, there is a risk that air cannot be properly taken in to the interior. Furthermore, in order to make the entire product compact, it is desirable to eliminate as much internal space as possible. Therefore, in this embodiment, a design is adopted in which almost no space is provided on the lower surface 250b side, and the cover part 62 of the optical device 60 is provided on the lower surface 250b side. Such a design also has advantages from the perspective of dust prevention. Furthermore, therefore, it is preferred that no air intake portion is provided on the lower surface 250b of the housing 250.

[0096] Furthermore, only one cooling fan 280 is provided in the housing 250 instead of a plurality of cooling fans 280 , thereby enabling the projection device 10 to be miniaturized.

[0097] Furthermore, a first heat sink 281 for the laser (blue laser diode 71) and a second heat sink 282 for the light-emitting diode (red light source 121) are provided, which is located closer to the cooling fan 280 than the first heat sink 281. This allows cooling air to be blown in ascending order of heat generation, further improving cooling efficiency.

[0098] Furthermore, the control circuit board 300 is disposed within the first air flow passage 91 provided above the optical device 60. In response to the operation of the cooling fan 280, air drawn in by the cooling fan 280 through the first air flow passage 91 cools the control circuit board 300. This allows the control circuit board 300, which includes electronic components that generate a high amount of heat, to be cooled effectively.

[0099] Furthermore, an IC heat sink 285 made of a metal plate member for cooling the IC chip 301 is disposed in the first air flow passage 91. This allows the IC chip 301, which generates a particularly high amount of heat, to be cooled satisfactorily.

[0100] Furthermore, the first air flow passage 91 is wider than the second air flow passage 92 provided below the optical device 60, and the flow resistance of the first air flow passage 91 is smaller than the flow resistance of the second air flow passage 92. Thus, sufficient space can be secured in the first air flow passage 91 to accommodate equipment that generates high heat.

[0101] Furthermore, the opening 61a of the optical device 60 is provided on the lower side of the housing 250 in the thickness direction, and the opening 61a is blocked by the cover member 62. Thus, by narrowing the gap between the lower side of the optical device 60 and the bottom plate of the housing 250, the amount of air flow, that is, the inflow of dust, can be reduced, thereby reducing the influx of dust into the interior of the optical device 60. Furthermore, there is no need to provide dust filters for the air intake sections 261 to 264.

[0102] Furthermore, housing 250 includes an intake and exhaust section comprising an intake section 262 and an exhaust section 260 on front surface 250e where projection port 11 is provided. The exhaust direction of exhaust section 260 is inclined away from the intake direction of intake section 262. This reduces the risk of heated air exhausted from exhaust section 260 disposed on front surface 250e being re-inhaled by intake section 262 without providing a separate flow path such as a duct, thereby enabling intake section 262 to be provided on front surface 250e as well.

[0103] Furthermore, housing 250 includes a metal shielding wall 252c having a plurality of flow holes 252c1 that, when viewed from the front, overlap with the plurality of intake and exhaust holes of the intake and exhaust section, namely, the plurality of intake holes 264a of intake section 264. This reduces adverse electrical effects on power supply circuit board 310, which is located near intake section 264. Furthermore, such a shielding wall 252c can be provided in an intake and exhaust section that includes not only intake section 264 but also the exhaust section, i.e., a section having intake and exhaust holes.

[0104] In addition, the embodiments described above are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other forms and can be omitted, replaced, or modified in various ways without departing from the scope of the invention. These embodiments and their modifications are included in the scope and spirit of the invention and are included in the invention described in the claims and their equivalents.

[0105] Industrial Applicability

[0106] According to the present invention, it is possible to provide a projection device that can be cooled satisfactorily by a single cooling fan.

[0107] Description of labels

[0108] 10 projection device 11 projection port

[0109] 12 Projection image adjustment unit 14 Output plug

[0110] 15 Power plug 21 Input / output connector

[0111] 22 Input / output interface 23 Image conversion unit

[0112] 24 Display encoder 25 Video RAM

[0113] 26 Display drive unit 31 Image compression / expansion unit

[0114] 32 memory card 35Ir receiving unit

[0115] 36Ir processing unit 37Key / indicator unit

[0116] 38 control unit 41 light source control circuit

[0117] 43 Cooling fan drive control circuit 45 Lens motor

[0118] 47 sound processing unit 48 speaker

[0119] 48a speaker unit 51 display element

[0120] 59 heat pipe 60 optical device

[0121] 61 Optical housing 61a opening

[0122] 62 cover parts 65 cover

[0123] 70 Excitation light irradiation device 71 Blue laser diode

[0124] 73 collimating lens 74 holding plate

[0125] 76 Reflector group 77 Condensing lens

[0126] 78 diffusion plate 79 heat pipe

[0127] 80 Green light source device 91 First air flow path

[0128] 92 Second air flow path 100 Fluorescent plate device

[0129] 101 fluorescent plate 110 motor

[0130] 117 condenser lens group 120 red light source device

[0131] 121 red light source 125 focusing lens group

[0132] 129 heat pipe 140 light guide optical system

[0133] 141 first dichroic mirror 143 first reflecting mirror

[0134] 145 second reflecting mirror 146 condenser lens

[0135] 147 condenser lens 148 second dichroic mirror

[0136] 149 condenser lens 170 light source side optical system

[0137] 173 condenser lens 175 microlens array

[0138] 179 optical axis conversion mirror 183 condenser lens

[0139] 185 illumination mirror 195 condenser

[0140] 220 projection side optical system 225 lens barrel

[0141] 235 movable lens group 250 housing

[0142] 250a upper surface 250b lower surface

[0143] 250c left side (second side) 250d right side (first side)

[0144] 250e front surface 250f rear surface

[0145] 250g left front corner 250h left rear corner

[0146] 250i right front corner 250j right rear corner

[0147] 251 Upper housing 251a upper side panel

[0148] 251b right upper panel part 252 lower shell

[0149] 252a lower side panel portion 252b right lower panel portion

[0150] 252c shielding wall 252c1 flow hole

[0151] 253 Left side panel 254 Front side panel

[0152] 254a Projection port opening 254b Inclined rib

[0153] 254c longitudinal rib 254d U-shaped rib

[0154] 254e partition plate 255 rear side panel

[0155] 256 transverse ribs 258 closing plate

[0156] 260 Exhaust section 261 Intake section

[0157] 262 air intake portion 262a right air intake portion

[0158] 262b Left side air intake section 263 Air intake section

[0159] 264 air intake portion 264a air intake hole

[0160] 270 grip portion 280 cooling fan

[0161] 280a Upper surface air intake 280b Lower surface air intake

[0162] 280c nozzle

[0163] 281 first heat sink 281a heat sink

[0164] 282 2nd heat sink 283 3rd heat sink

[0165] 285IC heat sink 285a abutment plate

[0166] 285b 1st heat sink 285c 2nd heat sink

[0167] 300 control circuit substrate 301 IC chip

[0168] 310 power circuit board

[0169] SB system bus

Claims

1. A projection device, characterized in that: have: Optical devices; A control circuit substrate is arranged on the upper side of the optical device; a cooling fan disposed near the air intake portion of the rear surface of the housing on the side opposite to the projection direction, and having an upper surface air intake port for sucking air from the upper surface and a lower surface air intake port for sucking air from the lower surface; as well as a heat sink, provided corresponding to the discharge port of the cooling fan and connected to the optical device; The flow path resistance on the lower surface air intake port side is smaller than the flow path resistance on the upper surface air intake port side.

2. The projection device according to claim 1, wherein The lower surface air intake port is larger than the upper surface air intake port.

3. The projection device according to claim 1 or 2, wherein: The cooling fan is arranged on the upper side of the housing in the thickness direction; A space below the cooling fan in the housing is larger than a space above the cooling fan in the housing.

4. The projection device according to any one of claims 1 to 3, wherein: The cooling fan is arranged near the first side surface of the housing; In response to the operation of the cooling fan, external air is taken into the housing from three surfaces of the housing: a front surface having a projection port, a second side surface opposite to the first side surface, and a rear surface opposite to the front surface; External air is not taken in from the first side surface.

5. The projection device according to any one of claims 1 to 4, wherein: In the housing, only one cooling fan is provided instead of multiple cooling fans.

6. The projection device according to any one of claims 1 to 5, wherein: The heat sink includes a first heat sink for the laser and a second heat sink for the light emitting diode located closer to the cooling fan than the first heat sink.

7. The projection device according to any one of claims 1 to 6, wherein: The control circuit substrate is arranged in a first air flow passage provided on the upper side of the optical device; In response to the operation of the cooling fan, the air taken in by the cooling fan through the first air flow path cools the control circuit board.

8. The projection device according to claim 7, wherein: An IC heat sink made of a metal plate member for cooling the IC chip is arranged in the first air flow passage.

9. The projection device according to claim 7 or 8, characterized in that: The first air flow passage is wider than a second air flow passage provided on the lower side of the optical device, and a flow resistance of the first air flow passage is smaller than a flow resistance of the second air flow passage.

10. The projection device according to any one of claims 1 to 9, wherein: The opening of the optical device is provided on the lower side of the housing in the thickness direction; The opening is blocked by a cover member.

11. The projection device according to any one of claims 1 to 10, wherein: The housing includes an air intake and exhaust portion having an air intake portion and an air exhaust portion at a front surface provided with a projection port; The exhaust direction of the exhaust portion is inclined in a direction away from the intake direction of the intake portion.

12. The projection device according to claim 11, wherein: The housing includes a metal shielding wall having a plurality of flow holes that overlap with the plurality of intake and exhaust holes of the intake and exhaust portion when viewed from the front.

Images