JP2017054014A - Image projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image projection device that can reduce a noise from the device and satisfactorily cool a power supply circuit board or a driving circuit board.SOLUTION: An image projection device, such as a projector comprises: a light source; a concave mirror that reflects an image formed by using light from the light source toward a projection surface; air blowing means, such as an exhaust fan 7 that generates an airflow in a main body housing; a power supply circuit board, such as a main power supply circuit board 80a that supplies power to electric components in the main body housing; and a light source driving circuit board, such as a ballast substrate that drives the light source. A channel, such as a first substrate cooling channel through which the air flows along the curve of the concave mirror, is formed on the back side of the concave mirror, and the power supply circuit board or the light source driving circuit board is arranged along the direction of flow of the air blown along the curve of the concave mirror.SELECTED DRAWING: Figure 27

Description

  The present invention relates to an image projection apparatus.

  Conventionally, based on image data from a personal computer or a video camera, an image is formed by an image forming unit using light emitted from a light source, and the image is enlarged by a concave mirror of a projection optical unit, and a screen or the like. 2. Description of the Related Art Image projection apparatuses that project and display on a screen are known.

  The image projection apparatus includes a ballast substrate as a light source driving circuit substrate for driving a light source, a power supply circuit substrate for supplying power to electrical components in the apparatus, and the like. For example, Patent Document 1 discloses an image in which an air suction port of an exhaust fan is surrounded by a power circuit board or a ballast board, and air flowing along the back surface of the concave mirror is introduced into the enclosed space to cool the board. A projection device is described.

  In recent years, there has been a demand for further noise reduction of devices, and there has been a demand for a reduction in the number of rotations of a fan as a blowing means and a reduction in the number of fans. By reducing the number of rotations of the fan, which is a blowing means, or by reducing the number of fans, the flow velocity of the air flowing in the apparatus main body is reduced.

  In the image projection apparatus described in Patent Document 1 described above, the substrate cooling formed by the air flowing behind the concave mirror surrounding the air suction port of the exhaust fan with a light source driving circuit board such as a power circuit board or a ballast board It flows into the air inlet of the space from an angle. The air flowing into the air inlet at an angle changes the flow direction suddenly, and the substrate cooling space along the substrate forms a substrate cooling space arranged so that the substrate surface is orthogonal to the air inlet. And exhausted by an exhaust fan.

  As described above, in the image projection apparatus described in Patent Document 1, the flow direction of the air flowing through the back side of the concave mirror changes abruptly. Therefore, the flow fluid resistance is large, and the air flowing into the substrate cooling space has a large flow resistance. The flow becomes slow. As a result, the flow velocity of the air flowing through the power supply circuit board and the ballast circuit board is lower than when flowing through the back side of the concave mirror. Therefore, in the configuration described in Patent Document 1, when the rotational speed of the fan as the air blowing unit is reduced or the number of fans is reduced to reduce the air flow in the apparatus, the power supply circuit board and the light source driving circuit board are improved. There was a possibility that it could not be cooled.

  In order to solve the above-described problems, the present invention provides a light source, a concave mirror that reflects an image formed by using light from the light source toward a projection surface, and an air blowing unit that generates an air flow in the main body casing. An image projection apparatus comprising: a power supply circuit board that supplies power to an electrical component in the main body casing; and a light source drive circuit board that drives the light source. The power supply circuit board or the light source drive circuit board includes: The main body housing is disposed on an inclined surface on the back surface side of the concave mirror.

  According to the present invention, the power supply circuit board or the light source drive circuit board can be cooled well.

FIG. 3 is an external perspective view showing a projector and a projection surface S. The internal perspective view which removed the exterior cover of the projector. The internal perspective view which removed except the lower sheet metal part of the main body housing | casing of a projector. The perspective view which shows the optical engine part etc. which were provided in the inside of a projector. The perspective view which shows a mode that the light source unit 15 is attached to a main body housing | casing. (A) is a schematic perspective view of a light source unit, (b) is the perspective view seen from the arrow b direction shown to Fig.6 (a). The perspective view which shows the state which removed except the light emission side part of the light source housing | casing. Sectional drawing cut | disconnected by the dashed-dotted line A of Fig.6 (a). The perspective view which looked back at the illumination part, the projection lens part, and the light modulation part. The figure which shows the optical system components accommodated in the illumination part with the light modulation part. The perspective view of a light modulation part. The perspective view which shows an optical engine part. The perspective view which shows the optical system components with which a projection optical unit is provided. The perspective view which shows the optical path from the projection lens part to the projection surface S. FIG. (A) is a perspective view which shows a light source cooling mechanism and an optical engine part, and is a perspective view which shows a light source cooling mechanism. (A) is a perspective view which shows a light source exhaust duct, (b) is sectional drawing which cut the light source exhaust duct by the dashed-dotted line E of Fig.16 (a). Sectional drawing which shows a part of metal mold | die which shape | molds a light source exhaust duct. The figure explaining the light which leaks from a light source unit. C sectional drawing of Fig.15 (a). B sectional drawing of Fig.15 (a). D sectional drawing of FIG.15 (b). (A) is the perspective view which looked at the projector which removed the upper sheet metal part, the rear sheet metal part, and the right sheet metal part of the main body case from the rear side, and (b) is the inside of the main body case of the projector (C) is a rear perspective view showing the inside of the main body housing of the projector with the mirror bracket of the projection optical unit removed. The block diagram of electric power supply. The perspective view which shows a front side metal plate part and a light source drive unit. The side view which shows an optical engine part and a light source drive unit. The perspective view which shows a front side metal plate part and a main power supply unit. The figure explaining the inclination of a main power supply circuit board. The figure which shows the flow of the substrate cooling air in the main body. KK sectional drawing of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the overall configuration of the image projection apparatus according to the present invention will be described.
FIG. 1 is an external perspective view showing a projector 1 as an image projection apparatus according to an embodiment of the present invention and a projection surface S such as a screen. In the following description, the projection surface S side of the projector 1 will be described as the rear side.

  The projector 1 is a device that forms a projection image based on image data input from a personal computer, a video camera, or the like, and projects and displays the projection image on a projection surface S such as a screen. In particular, liquid crystal projectors have recently been improved in terms of high resolution and low price due to high resolution of liquid crystal panels, high efficiency of light sources (lamps), and the like. In addition, small and light projectors 1 using DMD (Digital Micro-mirror Device), which is a micro-drive mirror device, have become widespread, and projectors 1 are widely used not only in offices and schools but also at home. . Front-type projectors have improved portability and are now being used for small meetings of several people. Such a projector is required to be able to project an image of a large screen (enlarge the projection screen) and to make the “projection space required outside the projector” as small as possible. As will be described later, in the projector 1 of the present embodiment, the projection optical system such as a projection lens is set parallel to the projection surface S, the light beam is folded by the folding mirror, and then the light beam is projected by the free-form mirror to the projection surface S. The projector is configured to magnify and project. With this configuration, it is possible to reduce the size of the optical engine unit in a vertical three-dimensional manner.

  The light flux of the projected image is emitted from the upper surface of the projector 1 and the light flux is projected onto the projection plane S. A focus lever 4a for adjusting the focus is provided on the side surface of the projector 1.

FIG. 2 is a perspective view of the projector 1 with the exterior cover removed. 2 (a) is a perspective view seen from the front side, FIG. 2 (b) is a perspective view seen from the rear side, and FIG. 2 (c) is an optical engine section arrangement side seen from the front side. FIG.
The projector 1 has a main body housing 14 that holds an optical engine unit 100, which will be described later, and various substrates such as a ballast substrate 12a. The main body housing 14 includes an upper sheet metal part 14a, a front sheet metal part 14b, a rear sheet metal part 14c, a lower sheet metal part 14d, and a right sheet metal part 14e. The housing 14 is formed by fixing the respective sheet metal portions with screws. The upper sheet metal portion 14a is formed with a projection opening 141 through which a light beam of the projected image passes. The front sheet metal portion 14b holds a ballast substrate unit, a main power supply unit 8a (see FIG. 26) described later, and the like. The rear sheet metal part 14c holds the sub power supply unit 8b and the like. The lower sheet metal part 14d holds an optical engine part and the like. Further, as shown in FIG. 2C, the right side sheet metal portion 14e is provided with a plurality of air inlets 10a to 10c and an operation opening 18 that allows the focus lever 4a to be operated.

FIG. 3 is an internal perspective view of the projector 1 with parts other than the lower sheet metal part 14d of the main body housing 14 removed. 3A is a perspective view of the inside of the projector 1 viewed from the front side, and FIG. 3B is a perspective view of the inside of the projector 1 viewed from the rear side.
The projector 1 includes an optical engine unit 100 and a light source unit 15 having a light source that emits white light. The optical engine unit 100 includes an image forming unit 3 as an image forming unit that forms an image using light from a light source, and a projection optical unit for projecting a light beam of an image formed by the image forming unit 3 onto a projection surface S. 2 are provided.

FIG. 4 is a perspective view showing the optical engine unit 100 and the like provided inside the projector 1.
The image forming unit 3 folds the light from the light source and the light modulation unit 30 having a DMD which is a micro-drive mirror device having a large number of micro mirrors that can be driven so as to change the inclination of the reflection surface, and irradiates the DMD. The illumination unit 20 is used. The light modulation unit 30, the illumination unit 20, and the projection optical unit 2 constituting the optical engine unit 100 are arranged side by side in the vertical direction. A light source housing 70 in which the light source unit 15 is housed is disposed on the right side of the illumination unit 20 in the drawing. On the upper surface of the light source housing 70, there is provided a housing exhaust port 70a through which air after light source cooling is exhausted.

FIG. 5 is a perspective view showing how the light source unit 15 is mounted on the main body housing.
As shown in FIG. 5, the light source unit 15 is configured to be detachable from the projector 1. Specifically, a light source attachment / detachment opening 141 f is formed on the left side surface of the main body housing 14. The light source attaching / detaching opening 141 f is formed by the front sheet metal part 14 b, the rear sheet metal part 14 c, the lower sheet metal part 14 d, and the exhaust fan 7 of the main body housing 14. The light source unit 15 is attached to the projector by being pushed into the main body housing in the direction of arrow K in the figure. An exhaust fan 7 is provided above the light source attaching / detaching opening 141f. As shown in FIG. 5, in this embodiment, the exhaust port of the housing is the exhaust port of the exhaust fan.

6A is a schematic perspective view of the light source unit 15, and FIG. 6B is a perspective view seen from the direction of the arrow b shown in FIG. 6A.
The light source unit 15 has a light source casing 151 made of a resin that houses a light source 160. A light source exhaust port 152 through which air after light source cooling is exhausted is provided on the upper surface portion 151a of the light source casing. As shown in FIG. 6B, the lower surface 151b of the light source casing 151 is provided with a second light source suction port 153 for taking air into the light source casing as will be described later. Further, the lower surface portion 151b is provided with a connector 154 that is connected to a power connector provided in the apparatus main body.

  The light emitting side surface 151c of the light source casing 151 has an opening 156 for allowing light from the light source to pass through. A glass plate 157 is attached to the opening 156. Further, two light source positioning protrusions 155a and 155b are provided on the diagonal line on the light emitting side surface portion 151c. These light source positioning protrusions 155a and 155b are inserted into light source positioning holes 26c (see FIG. 9) provided in the illumination unit, and the light source unit 15 is positioned in the illumination unit 20. In addition, a housing attachment portion 151d is provided at the opposite end of the light source unit 15 on the opposite side to the light emitting side (see FIG. 5). These housing attachment portions 151d are provided with fitting projections 151e, and these fitting projections 151e fit into the fitting hole portions provided in the light source attachment concave portion 141g of the main body housing shown in FIG. Thus, the light source unit 15 is attached to the main body housing 14.

  In addition, the light emission side surface portion 151 c of the light source housing 151 is provided with an inflow port 158 a through which air flows into the reflector of the light source 160. The inflow port 158a is provided with an explosion-proof mesh 159 that prevents the fragments from diffusing when the arc tube of the light source is ruptured.

FIG. 7 is a perspective view showing a state in which the light source casing other than the light emission side surface portion 151c is removed.
As shown in FIG. 7, the reflector 161 of the light source 160 is attached to the light emitting side surface portion 151c, and the opening portion of the reflector 161 is closed by the light emitting side surface portion 151c. Further, an outlet 158b through which the air in the reflector 161 flows out is provided at the upper part of the light emitting side surface portion 151c. The outflow port 158b is also provided with an explosion-proof mesh 159.

FIG. 8 is a cross-sectional view taken along the alternate long and short dash line A in FIG.
The light source 160 is a discharge lamp such as a halogen lamp, a metal halide lamp, or a high-pressure mercury lamp, and includes a light-emitting tube 162 having a light-emitting portion 162a in which high-pressure gas is confined. Further, the light source 160 includes a reflector 161 as a reflecting member that reflects light emitted from the light emitting unit 162a. The reflector 161 has a mortar shape (substantially conical shape), and an arc tube 162 is attached to the bottom of the reflector 161. Moreover, it has the electrode part 163 provided with the electrode terminal 163a (refer FIG. 7) connected to the arc_tube | light_emitting_tube 162. FIG. The electrode terminal 163a is connected to the connector 154 via a conducting wire 164.

  The light emitted from the light emitting portion 162 a of the light source 160 is collected by the reflector 161 at the opening 156 of the light emitting side surface portion 151 c, passes through the glass plate 157, and is emitted from the light source unit 15.

FIG. 9 is a perspective view of the illumination unit 20, the projection lens unit 4, and the light modulation unit 30 as viewed from the rear side. FIG. FIG.
As shown in FIG. 10, the illumination unit 20 includes a color wheel 21, a light tunnel 22, two relay lenses 23, a cylinder mirror 24, and a concave mirror 25, and these include an illumination bracket 26 shown in FIG. 9. Is held in.

  The color wheel 21 has a disk shape and is fixed to the rotating portion of the color motor 21a. The color wheel 21 is provided with filters such as R (red), G (green), and B (blue) in the rotation direction. The light tunnel 22 has a rectangular tube shape, and the inner peripheral surface thereof is a mirror surface.

  As shown in FIG. 9, an OFF light plate 27 is attached to the rear side surface of the illumination bracket 26. Further, the illumination bracket 26 has four leg portions 26b, and the leg portion 26b opposite to the light source unit 15 side penetrates the light modulation portion 30 as shown in FIG. These four legs 26 b are attached to the lower sheet metal part 14 d of the main body housing 14 and support the weight of the optical engine part 100. Further, by providing the leg portion, a space for the outside air to flow in is formed in the heat sink 33 (see FIG. 11) as a cooling means for cooling the DMD 32 of the light modulation portion 30.

  The projection lens unit 4 is disposed above the illumination unit 20 and includes a plurality of lenses. The projection lens unit 4 is held by a lens holder 41. The lens holder 41 is provided with a plurality of through holes 41a through which screws pass. The projection lens unit 4 is screwed to the base member 54 (see FIG. 13A) of the projection optical unit 2 described later by inserting screws into these through holes 41a.

  Further, a light source positioning hole 26c into which light source positioning protrusions 155a and 155b (see FIG. 6) provided on the light emitting side surface portion 151c of the light source casing 151 are inserted is provided at the light source unit side end of the illumination bracket 26. ing.

  The illumination bracket 26 is provided with a cooling member 28 made of aluminum that covers the color wheel 21 and dissipates heat from the color wheel 21 and the color motor 21a. Further, a wheel cover 29 that covers a surface of the color wheel 21 that faces the light source 160 is provided. The wheel cover 29 is provided with a through hole 29 a for allowing light from the light source 160 to pass therethrough.

  As shown in FIG. 10, the light collected by the reflector 161 passes through the glass plate 157 and reaches the peripheral end of the color wheel 21. The light that reaches the peripheral end of the color wheel 21 is separated into R, G, and B light in a time-sharing manner by the rotation of the color wheel 21.

  The light separated by the color wheel 21 enters the light tunnel 22. The light tunnel 22 has a rectangular tube shape, and the inner peripheral surface thereof is a mirror surface. The light that has entered the light tunnel 22 is reflected by the inner peripheral surface of the light tunnel 22 a plurality of times, is converted into a uniform surface light source, and is emitted toward the relay lens 23.

  The light passing through the light tunnel 22 passes through the two relay lenses 23, is reflected by the cylinder mirror 24 and the concave mirror 25, and is condensed and imaged on the image generation surface of the DMD 32.

FIG. 11 is a perspective view of the light modulation unit 30.
As shown in FIG. 11, the light modulation unit 30 includes a DMD board 31 on which a DMD 32 is mounted. The DMD 32 is mounted on a socket 31a provided on the DMD board 31 with an image generation surface on which micromirrors are arranged in a lattice shape facing upward. The DMD board 31 is provided with a drive circuit for driving the DMD mirror. A heat sink 33 as a cooling means for cooling the DMD 32 is fixed to the back surface of the DMD board 31 (the surface opposite to the surface on which the socket 31 a is provided). A portion of the DMD board 31 where the DMD 32 is mounted has a through-hole, and the heat sink 33 has a protrusion that is inserted into the through-hole. The tip of the protrusion is flat, and the protrusion is inserted into the through-hole so that the flat surface at the tip of the protrusion is in contact with the back surface of DMD 32 (the surface opposite to the image generation surface). A heat transfer sheet that can be elastically deformed is affixed to the flat portion or the place where the heat sink 33 on the back surface of the DMD 32 abuts to improve the adhesion between the flat portion of the protrusion and the back surface of the DMD 32, thereby increasing the thermal conductivity. Also good.
The heat sink 33 is pressed and fixed to the surface opposite to the surface on which the socket 31 a of the DMD board 31 is provided by the fixing member 34.

A plurality of movable micromirrors are arranged in a lattice pattern on the image generation surface of the DMD 32. Each micromirror can tilt the mirror surface by a predetermined angle around the twist axis, and can have two states of “ON” and “OFF”. When the micromirror is “ON”, the light from the light source 160 is reflected toward the projection lens unit 4 as shown in FIG. When “OFF”, the light from the light source 160 is reflected toward the OFF light plate 27 held on the side surface of the illumination bracket 26 shown in FIG. 9 (in a direction orthogonal to the paper surface of FIG. 10). Therefore, by driving each mirror individually, light projection can be controlled for each pixel of the image data, and an image can be generated.
The light irradiated to the OFF light plate 27 becomes heat and is absorbed by the OFF light plate 27 and is cooled by the flow of the outside air.

FIG. 12 is a perspective view showing the optical engine unit 100.
The projection optical unit 2 includes a mirror bracket 53 that holds the folding mirror 52 and the dust-proof glass 51, and a free mirror bracket 6 that holds the concave mirror 5 (see FIG. 13). At the left and right ends of the free mirror bracket 6, two holes 6a extending in the rearward direction are provided at predetermined intervals in the vertical direction. The free mirror bracket 6 is attached to the mirror bracket 53 by snap fit by fitting the claw portions 53a provided on the mirror bracket 53 into the holes 6a. The mirror bracket 53 is attached to the base member 54. A base member 54 to which the lens holder 41 and the mirror bracket 53 are attached is screwed to the illumination bracket 26.

  FIG. 13 is a perspective view showing a state in which the mirror bracket 53 and the free mirror bracket 6 of the projection optical unit 2 are removed. The projection optical unit 2 includes a projection lens unit 4, a folding mirror 52, a concave mirror 5, a dustproof glass 51, and the like. The concave reflecting surface that reflects the light of the concave mirror 5 can be a spherical surface, a rotationally symmetric aspherical surface, a free-form surface, or the like.

FIG. 14 is a perspective view showing an optical path from the projection lens unit 4 to the projection surface S (screen).
The projection image formed by the DMD is transmitted through the projection lens unit 4 that is the first optical system, and forms an intermediate image conjugate with the image generated by the DMD 32 between the folding mirror 52 and the concave mirror 5. This intermediate image is formed as a curved image between the folding mirror 52 and the concave mirror 5 which are the second optical system. Next, the divergent light beam after forming the intermediate image is incident on the concave mirror 5 to become a convergent light beam, and the concave mirror 5 converts the intermediate image into a “further enlarged image” and is projected onto the projection surface S. To do.

  In this way, the projection optical system is constituted by the first optical system and the second optical system, an intermediate image is formed between the first optical system and the concave mirror 5 of the second optical system, and the concave mirror 5 By enlarging and projecting with, the projection distance can be shortened and it can be used even in a narrow conference room.

Next, cooling of the light source unit 15 will be described.
FIG. 15A is a perspective view showing a light source cooling mechanism that cools the light source unit 15 and the optical engine unit 100, and FIG. 15B is a perspective view showing the light source cooling mechanism.
The light source cooling mechanism includes a light source blower 71, a light source exhaust duct 80, an exhaust fan 7, and the like. In the present embodiment, a double-sided intake sirocco fan is used as the light source blower 71, and an exhaust port of the light source blower 71 is connected to an intake duct portion 70c provided in the light source housing. The light source exhaust duct 80 is attached to the light source housing 70 so as to cover the upper surface portion of the light source housing 70.

  Side walls extending downward are provided at both ends in the front-rear direction of the bottom surface 70d of the light source housing 70, and two attachment portions 70e are provided on the side walls at predetermined intervals. These mounting portions are provided with through holes through which screws pass. The light source housing has a bottom surface 70d having a predetermined gap with respect to the lower sheet metal part 14d, by inserting screws into the through holes of the respective attachment parts and stopping the screws in the screw holes of the lower sheet metal part. It is attached to the side sheet metal part 14d. The bottom surface 70d is provided with an air intake port 70b for taking in air for cooling the region outside the reflector of the light source, as will be described later (see FIGS. 20 and 21).

FIG. 16A is a perspective view showing the light source exhaust duct 80, and FIG. 16B is a cross-sectional view of the light source exhaust duct 80 taken along the alternate long and short dash line E in FIG.
The light source exhaust duct 80 is formed of a resin and has a fan holding portion 81 that holds an exhaust fan, an exhaust guide portion 82 that guides the cooled air that has cooled the light source unit, a fan attachment portion 86 to which the exhaust fan 7 is attached, a light source 160 has an inflow portion 85 or the like into which air after cooling flows. The fan holding portion 81 includes a bottom surface portion 81a that faces the lower surface of the exhaust fan, and a facing surface portion 81b that extends straight upward from both front and rear direction ends of the bottom surface portion 81a and faces the side surface of the exhaust fan. The fan holding portion 81 holds the exhaust fan so as to surround the lower portion of the exhaust fan other than the intake port and the exhaust port.

  A fan mounting portion 86 to which the exhaust fan 7 is mounted is provided at the upper end of each facing surface portion 81b of the fan holding portion 81. Each fan mounting portion 86 is provided with a screw hole, and the exhaust fan 7 is screwed to the fan mounting portion 86.

  The exhaust guide portion 82 includes four duct portions 82a, 82b, 82c, and 82d, and these four duct portions are arranged side by side in the direction of the rotation axis of the exhaust fan. In addition, the air inlets serving as the air intakes of the ducts 82 a, 82 b, 82 c, and 82 d are arranged facing the light source 161. Each duct portion is provided with air guide wall portions 83a, 83b, 83c and 83d for guiding air flowing through the duct portion. Of the four duct parts, the first duct part 82a arranged closest to the exhaust fan and the second duct part 82b adjacent to the first duct part 82a guide the air flowing through the second duct part. It is partitioned off by two wind guide walls 83b. The second duct portion 82b and the third duct portion 82c adjacent to the second duct portion 82b are partitioned by a third air guide wall portion 83c that guides the air flowing through the third duct portion 82c. Further, the third duct portion 82c and the fourth duct portion 82d arranged at the position farthest from the exhaust fan are partitioned by a fourth air guide wall portion 83d for guiding the air flowing through the fourth duct portion 82d. Yes.

  Further, as shown in FIG. 16B, the position of the upper end of the air guide wall portion is positioned higher as the distance from the exhaust fan increases, and the length of the first duct portion 82a is set to L1, and the second duct. When the length of the portion 82b is L2, the length of the third duct portion 82c is L3, and the length of the fourth duct portion 82d is L4, L1 <L2 <L3 <L4. That is, the length of the duct portion becomes longer as the distance from the exhaust fan increases, so that the air in the duct is discharged toward the exhaust fan from a higher position as the duct portion is further away from the exhaust fan.

  Further, the opening area of the intake port of the first duct portion 82a is d1, the opening area of the intake port of the second duct portion 82b is d2, the opening area of the intake port of the third duct portion 82c is d3, and the fourth duct portion 82d When the opening area of the intake port is d4, d1> d2> d3> d4. That is, as the duct part is farther from the exhaust fan, the opening area of the intake port is smaller and the air is less likely to flow.

  Further, the minimum flow area of the first duct portion 82a is D1, the minimum flow area of the second duct portion 82b is D2, the minimum flow area of the third duct portion 82c is D3, and the fourth duct portion 82d is When the minimum cross-sectional area of the flow path is D4, D1> D2> D3> D4. That is, the flow path cross-sectional area is smaller as the duct part is farther from the exhaust fan, and the air is less likely to flow and the influence of the intake force of the exhaust fan 7 is weaker as the duct part is farther from the exhaust fan.

The first air guide wall portion 83a arranged closest to the exhaust fan for guiding the air flowing into the first duct portion 82a extends in the vertical direction, which is a direction perpendicular to the rotational axis direction of the exhaust fan. In addition, the first air guide wall portion 83a is inclined such that the upper side downstream in the air flow direction in the first duct portion is farther from the exhaust fan than the lower side. The second, third, and fourth air guide wall portions 83b, 83c, and 83d extend straight upward and are inclined in the direction away from the exhaust fan in the middle.
On the surface of the portion of each wind guide wall portion that is inclined away from the exhaust fan, a fine concavo-convex pattern as a light diffusion portion is formed (hereinafter, the surface on which the crease is formed is referred to as a crease surface Z). ). In the present embodiment, both surfaces of the inclined portion are the textured surface Z.

  Further, the wall portion 84 on the exhaust fan side of the inflow portion 85 is also inclined so that the upper portion is separated from the exhaust fan, and the air after cooling the outside of the reflector of the light source that flows into the inflow portion as described later. It has a function as a guide leading to the first duct part and the second duct part. Both sides of the wall portion 84 also have a textured surface Z.

FIG. 17 is a cross-sectional view showing a part of a mold for molding the light source exhaust duct 80.
The light source exhaust duct 80 is an injection molded product of resin, and as shown in FIG. 17, at least each duct part is molded by a first mold 701 and a second mold 702. In order to mold the light source exhaust duct 80 having a duct portion having a certain length in a direction orthogonal to the rotation axis direction of the exhaust fan 7 with a rectangular cross section of the flow path, The moving directions X1 and X2 of the mold need to be the same as the direction in which the duct portion extends. The texture formed on each air guide wall is formed by roughening a portion corresponding to a portion to which the texture of the mold is applied with sandblasting or the like. In this case, the embossed surface Z needs to be provided with a so-called slip-off slope that is inclined at a predetermined angle with respect to the movement directions X1 and X2 of the mold due to the problem of mold-release characteristics. For this reason, it is necessary to incline the portion of each wind guide wall portion to be textured with respect to the direction in which the duct portion extends. As shown in FIG. 17, a textured surface Z facing the exhaust fan of the wind guide wall is formed by a first mold 701 that moves in the X1 direction in the drawing. On the other hand, the embossed surface Z opposite to the surface facing the exhaust fan of the air guide wall is formed by a second mold 702 that moves in the X2 direction in the drawing.

  In order to form the embossed surface Z on the air guide wall portion, it is only necessary that the portion of the air guide wall portion where the emboss is formed is inclined at a predetermined angle with respect to the moving direction of the mold. Therefore, the embossing can be formed even if the part of the air guiding wall portion where the embossing is formed is inclined so as to approach the exhaust fan. However, by tilting the portion of the air guide wall where the texture is formed in the direction away from the exhaust fan as in this embodiment, the following advantages can be obtained compared to the case of tilting closer to the exhaust fan. Can be obtained.

FIG. 18 is a diagram illustrating light leaking from the light source unit.
As shown in FIG. 18, part of the light emitted from the light emitting unit 162 a and directed to the reflector 161 is transmitted through the reflector 161. The light transmitted through the reflector 161 passes through the light source exhaust port 152 of the light source unit and the housing exhaust port 70a and enters the duct portion. Further, the light emitted from the light emitting part 162a leaks out from the outlet 158b at the upper part of the light emitting side part 151c, and enters the duct part.

  As shown by the chain line in FIG. 18, when the portion where the textured portion of the air guide wall portion is tilted so as to approach the exhaust fan, when the user looks inside the casing from the exhaust port of the outer case, the reflector of the light source I will peep up to 161. As a result, as indicated by a solid line arrow in the figure, strong light incident on the duct portion may leak from the exhaust fan directly without being reflected by the wind guide wall portion. That is, the strong light incident on the duct portion may leak out without being incident on the embossed surface Z, and there is a possibility that it does not make sense to form the embossed surface Z.

  On the other hand, as in the present embodiment, when the portion of the air guide wall portion where the texture is formed is tilted away from the exhaust fan, the air passage forming portion of the air guide wall portion covers the inside of the duct portion. . As a result, even if the user looks inside the housing from the exhaust port of the exterior case, the user can only see the textured surface Z on the side of the air guide wall facing the exhaust fan. As a result, the light leaking from the exhaust fan is reflected at least once by the embossed surface of the wind guide wall portion facing the exhaust fan. The light incident on the textured surface Z is diffused by being diffusely reflected by the fine uneven shape on the surface and becomes light whose intensity is weakened. Therefore, even if the user looks inside the housing from the exhaust port of the exterior case, it is the weak light that reaches the user's eyes, the user does not feel dazzling, and does not feel uncomfortable during use The advantage that can be obtained.

  Moreover, in this embodiment, the embossing is formed in both surfaces of the baffle wall part. Thereby, it is possible to increase the light incident on the textured surface Z a plurality of times before passing through the duct portion. Thereby, light can be diffused a plurality of times, and light that leaks from the duct portion and travels toward the exhaust fan can be further weakened.

  In addition, by tilting the portion of the air guide wall portion where the texture is formed away from the exhaust fan, the incident angle of light incident on the texture surface Z opposite to the surface facing the exhaust fan is changed to the air guide wall portion. Can be narrower than the case of extending straight in the vertical direction. Thereby, it becomes possible to increase the frequency | count of reflecting in a duct part. Since light attenuates every time it reflects off the air guide wall made of resin, it can leak out from the duct and further weaken the light toward the exhaust fan. Furthermore, the light incident on the textured surface Z can be increased a plurality of times, and the light leaking from the exhaust fan can be further weakened.

Next, the flow of air for cooling the light source will be described.
19 is a cross-sectional view taken along the line C in FIG. 15A, and FIG. 20 is a cross-sectional view taken along the line B in FIG. FIG. 21 is a cross-sectional view taken along the line D in FIG.
As shown in FIG. 19, air around the light source blower of the main body casing is sucked by the light source blower 71. Due to this suction, the area around the light source blower 71 in the main body casing becomes negative pressure, and outside air is taken in from the third air inlet 10c below the right sheet metal part 14e shown in FIG. The taken-in outside air flows to the heat sink 33 (see FIG. 11) that cools the DMD 32 and cools the heat sink 33. Thereby, the heat sink 33 can efficiently release the heat of the DMD 32, and the temperature rise of the DMD 32 can be suppressed.

  Air sucked by the light source blower 71 (hereinafter referred to as first air) flows from the exhaust port of the light source blower 71 to the intake duct portion 70c of the light source housing 70, passes through the inlet 158a of the light source casing 151, and is reflected by the reflector. 161 flows into the inside. A wind direction plate 158 c is disposed inside the reflector 161. A part of the first air that has flowed into the reflector 161 from the inlet 158 a of the light source casing 151 flows toward the light emitting part 162 a of the arc tube 162 by the wind direction plate 158 c, and the rest of the air is supplied to the arc tube 162. It flows toward the tip. Thereby, the arc tube 162 can be air-cooled with good balance. The first air after cooling the arc tube 162 flows into the outside of the reflector 161 from the outlet 158b as shown in FIGS. 20 and 21 due to the extrusion from the light source blower and the drawing of the exhaust fan.

  Further, as shown in FIGS. 20 and 21, due to the suction force of the exhaust fan 7, the air intake port 70 b is inserted into the air intake port 70 b from the space between the bottom surface 70 d of the light source housing 70 and the lower sheet metal part 14 d of the main body housing. Air flows in. Air that has flowed into the air intake port 70b (hereinafter referred to as second air) flows into the space outside the reflector of the light source housing 151 through the second light source suction port 153, and cools the electrode portion 163 of the light source and the like. .

  The first air that has cooled the inside of the reflector 161 and the second air that has cooled the electrode portion 163 of the light source pass through the light source exhaust port 152 and the housing exhaust port 70a of the light source housing, and the inflow portion 85 of the light source exhaust duct 80. Flow into.

  When a discharge lamp such as a halogen lamp, a metal halide lamp, or a high pressure mercury lamp is used as the light source, the temperature of the arc tube 162 reaches 1000 ° C. Therefore, the first air after cooling the arc tube 162 has a high temperature. Become. If the light source exhaust port 152 is disposed immediately above the outlet port 158b, the first air heated to a high temperature by cooling the arc tube 162 is directly used as the third duct part 82c or the fourth duct as the first duct. It will flow to the duct part 82d. And the low temperature 2nd air which flowed out from the exhaust port of the 3rd duct part 82c or the 4th duct part 82d, and flowed through the 1st duct part 82a and the 2nd duct part 82b which are 2nd ducts, and a light source exhaust duct Then, it is mixed above 80 and exhausted through the exhaust fan 7 to the outside of the apparatus.

  However, in order to cool the hot arc tube 162 satisfactorily, the first air flows by both the push of the light source blower 71 and the suction of the exhaust fan, whereas the second air is an exhaust fan. 7 is sucked only. Therefore, the first air has a higher flow rate and a higher flow rate than the second air. Therefore, the first air and the second air cannot be sufficiently mixed above the light source exhaust duct 80 and are discharged outside the apparatus. Further, the second air flowing through the first duct portion 82a and the second duct portion 82b close to the exhaust fan 7 is mainly exhausted from the region below the rotating shaft portion of the exhaust fan 7 to the outside of the machine. On the other hand, the first air flowing through the third and fourth duct portions 82c and 82d is mainly exhausted from the region above the rotating shaft portion of the exhaust fan to the outside of the machine. As a result, there is a concern that a clear bias occurs in the distribution of the exhaust temperature exhausted from the exhaust port of the exterior cover.

  Further, the applicant applies the high temperature first air and the low temperature second air to the shaft portion of the exhaust fan 7 to mix the first air and the low temperature second air, There has been proposed an image projection apparatus that exhausts air after the temperature is lowered in the housing (Japanese Patent No. 5637469). However, in such a configuration, since the high-temperature first air after cooling the arc tube 162 strikes the rotation center portion of the exhaust fan 7, the temperature of the rotation shaft portion of the exhaust fan 7 rises. The rotating shaft portion is provided with a bearing or the like, and when the temperature of the rotating shaft portion rises, the thermal deterioration of the bearing advances, and the exhaust fan reaches the end of its life at an early stage. In other words, it can be said that the configuration disclosed in Japanese Patent No. 5537469 is a configuration that realizes suppression of hot spots while sacrificing the life of the exhaust fan.

  In contrast, the configuration of the present embodiment distributes the first air so that the high-temperature first air flows through all the duct portions, and the exhaust temperature distribution exhausted from the exhaust port of the exterior cover. The occurrence of bias is suppressed.

  In the present embodiment, as shown in FIG. 21, the light source exhaust port 152 of the light source casing 151 serving as the light source storage unit is disposed upstream of the outflow port 158b in the light emission direction of the light source (right side in the drawing). . Therefore, the outlet 158b is separated from the third duct part 82c and the fourth duct part 82d by the upper surface part 151a of the light source casing. As a result, the flow direction of the first air flowing out from the outlet 158b to the light source casing 151 is suddenly changed from above to the upstream direction of the light emission direction of the light source. Then, due to the suction force of the exhaust fan, the flow direction suddenly changes upward from the upstream direction of the light emission direction and flows to the light source exhaust port 152.

  A sudden change in the direction of flow increases the fluid resistance and slows the flow of the first air. Thereby, the flow velocity difference with the second air is reduced, and it becomes easy to mix with the second air. The second air flows upward and travels toward the light source exhaust port 152. Therefore, the first air flows from the direction orthogonal to the flow direction of the second air and travels toward the light source exhaust port 152. As a result, a part of the first air is mixed with the second air before the light source exhaust port 152, and the temperature is lowered. Then, the first air and the second air flow into the inflow portion 85 of the light source exhaust duct 80 through the light source exhaust port 152 and the housing exhaust port 70a.

  As shown in FIG. 21, the first air mainly enters the light source exhaust duct 80 through the light source exhaust port 152 and the edge of the housing exhaust port 70a far from the exhaust fan 7 (left side in the figure). Flows into section 85. The edges of the housing exhaust port 70a and the light source exhaust port 152 on the side far from the exhaust fan 7 are located closer to the second duct portion 82b than the central portion of the third duct portion 82c. For this reason, the first air is shaped to flow between the second duct portion 82b and the third duct portion 82c of the inflow portion 85. On the other hand, the second air mainly flows through the light source exhaust port 152 and the side of the housing exhaust port 70a close to the exhaust fan (the right side in the drawing) into the inflow portion 85 of the light source exhaust duct 80. As a result, the second air flows between the first duct portion 82a and the second duct portion 82b of the inflow portion 85.

  In the present embodiment, as shown in FIG. 16, the opening area of the intake port of each duct portion is made smaller as the duct portion is farther from the exhaust fan, and air is less likely to flow in as the duct portion is farther from the exhaust fan. Yes. Moreover, the flow path cross-sectional area is smaller as the duct part is farther from the exhaust fan, and the air is less likely to flow as the duct part is farther from the exhaust fan. As the duct part is farther from the exhaust fan, the suction force of the exhaust fan becomes weaker and the air does not flow easily, but in this embodiment, the opening area of the exhaust port and the minimum channel cross-sectional area of each duct part are separated from the exhaust fan. The smaller the duct portion is, and the more the duct portion is farther from the exhaust fan, the more difficult it is for air to flow in.

The second air flowing between the first duct portion 82a and the second duct portion 82b of the inflow portion 85 flows into the first duct portion 82a and the second duct portion 82b. This is for the following three reasons.
1. It is difficult for air to flow into the third duct part 82c and the fourth duct part 82d.
2. The first air flowing from the side farther from the exhaust fan than the second air is prevented from flowing into the third duct part 82c and the fourth duct part 82d.
3. Air may easily flow into the first duct portion 82a and the second duct portion 82b.
For these three reasons, the second air flows into the first duct portion 82a and the second duct portion 82b. In the present embodiment, since the wall portion 84 on the exhaust fan side of the inflow portion 85 is inclined so that the upper portion is separated from the exhaust fan, the second air flowing into the exhaust fan side of the inflow portion 85 is It is guided and smoothly flows into the first duct part 82a and the second duct part 82b. Thereby, the fall of flow velocity can be suppressed and the 2nd air can be sent through the 1st duct part 82a and the 2nd duct part 82b.

  On the other hand, the first air that flows between the second duct portion 82b and the third duct portion 82c of the inflow portion 85 flows into all the duct portions 82a to 82d. As described above, in the third duct portion and the fourth duct portion, air hardly flows and the suction force of the exhaust fan is also weak. On the other hand, in the first and second duct portions, air easily flows and the suction force of the exhaust fan is strong. As a result, a part of the first air flowing between the second duct portion 82b and the third duct portion 82c of the inflow portion 85 is strongly affected by the suction force of the exhaust fan, and the opening area of the intake port is wide. The air flows into the first duct part 82a and the second duct part 82b where the air easily flows. Then, the remaining first air flows into the third duct part 82c and the fourth duct part 82d. In this way, the first air flows in a distributed manner in each duct portion, and the flow rate of the air flowing into each duct portion is reduced.

Here, as a method of lowering the temperature of the hot air after cooling the arc tube and exhausting it out of the device,
(I) Reduce the temperature of hot air by mixing with low temperature air (II) Reduce the temperature of hot air by lengthening the flow path (III) Unit area by exhausting high temperature air over a wide area There are three ways to reduce the amount of heat per hit.

  The high temperature first air and the low temperature second air flow into the first duct portion 82a and the second duct portion 82b while mixing, and further move while mixing within the duct portions. And the mixed air of the 1st air and 2nd air which came out of these duct parts is exhausted outside the apparatus from the area | region below the rotating shaft part 7a of the exhaust fan 7. FIG. That is, in the first duct portion 82a and the second duct portion 82b, the high-temperature air is lowered by the method (I) described above and exhausted outside the apparatus.

  In order to air-cool the high-temperature arc tube 162 satisfactorily, it is necessary to increase the flow rate of air flowing through the arc tube 162 and to flow cooling air from the next to the arc tube 162. Therefore, the first air that cools the arc tube 162 flows by using both the extrusion by the light source blower 71 and the suction of the air by the exhaust fan 7. On the other hand, the second air flows only by the suction of the exhaust fan 7, and the flow rate of the first air is larger than that of the second air. However, in the present embodiment, the flow rate of the first air flowing to each duct portion is reduced by dispersing the first air into the four duct portions. Thereby, in the 1st duct part 82a and the 2nd duct part 82b, temperature can be reduced favorably by mixing with 2nd air.

  Further, as described above, the first air flows into the inflow portion 85 in a state where the flow direction is suddenly changed before flowing into the inflow portion 85 and the flow velocity is lowered, and a part of the first air flows. It flows into the duct part 82a and the second duct part 82b. On the other hand, the second air flows into the inflow portion 85 without causing a sudden change in the flow direction, and is guided to the wall portion 84 on the exhaust fan side of the inflow portion 85, and the first duct portion 82 a. Or flows into the second duct portion 82b. Therefore, the second air flows into the first duct portion 82a and the second duct portion 82b while suppressing a decrease in the flow velocity. Therefore, when the first air that has flowed faster than the second air when flowing inside the reflector flows into the first duct portion 82a and the second duct portion 82b, the first air and the second air The difference in flow rate from the air is reduced. As a result, the first air can be mixed well with the second air in the first duct portion 82a and the second duct portion 82b, and the temperature can be lowered well and exhausted.

  On the other hand, only the substantially hot first air flows into the third duct portion 82c and the fourth duct portion 82d, and the high temperature air cannot be lowered by the method (I). Therefore, in the present embodiment, the remaining first air that has flowed into the third duct portion 82c and the fourth duct portion is reduced in temperature by the methods (II) and (III) above, and is moved out of the apparatus. Exhaust.

  Specifically, in order to lengthen the flow path of (II), the length of the duct portion is increased as the distance from the exhaust fan increases, and the lengths of the third duct portion 82c and the fourth duct portion 82d are increased. It is longer than the one duct part 82a and the second duct part 82b. Further, the position of the upper end of the third air guide wall portion 83c for guiding the air of the third duct portion 82c and the fourth air guide wall portion 83d for guiding the air of the fourth duct portion 82d is defined as the air of the first duct portion 82a. Are made higher than the first wind guide wall portion 83a for guiding the air and the second wind guide wall portion 83b for guiding the air in the second duct portion 82b. As a result, the air flowing through the third duct portion 82c and the fourth duct portion 82d is exhausted from above the rotating shaft portion 7a of the exhaust fan. By exhausting the exhaust fan to the upper part of the rotating shaft part 7a, the flow path until the exhaust fan is exhausted can be made longer than when exhausting to the lower part of the exhaust fan rotating shaft part 7a. .

  In this way, by making the flow path longer, heat escapes until exhausted. Thereby, the temperature of the remaining 1st air which flowed into the 3rd duct part 82c and the 4th duct part 82d can be reduced.

  Further, the exhaust ports of the third duct part 82c and the fourth duct part 82d are located farther from the exhaust fan than the exhaust ports of the first duct part and the second duct part. The exhaust ports of the first duct part and the second duct part are located close to the exhaust fan. Therefore, the air exhausted from the first duct portion and the second duct portion is strongly drawn in by the suction force of the exhaust fan, and vigorously flows toward the exhaust fan without being diffused. Exhausted from the spot.

  On the other hand, since the remaining first air exhausted from the third duct part 82c and the fourth duct part 82d is exhausted at a position away from the exhaust fan 7, the suction force of the exhaust fan 7 is weak and gradually. Toward the exhaust fan 7. Furthermore, since the flow paths of the third duct part 82c and the fourth duct part 82d are long, the remaining first air exhausted from the third duct part 82c and the fourth duct part 82d is sufficiently decelerated by the flow resistance. The flow rate is significantly reduced. Accordingly, the remaining first air exhausted from the third duct part 82c and the fourth duct part 82d gradually moves toward the exhaust fan 7 while diffusing, and is located above the rotating shaft part 7a of the exhaust fan 7. Exhausted from the whole. Thus, the remaining first air exhausted from the third duct part 82c and the fourth duct part 82d is diffused widely, so that the amount of heat per unit area is reduced and exhausted from the exhaust fan 7. The temperature of the air can be lowered. As described above, the temperature of the remaining high-temperature first air flowing in the third duct portion 82c and the fourth duct portion 82d is lowered in the casing by the method (II). Further, the amount of heat per unit area is reduced by the method (III). As a result, the remaining first air is exhausted by the exhaust fan while the temperature is lowered.

  As described above, in the present embodiment, the opening area of the intake port is increased for the first duct portion and the second duct portion, which have a strong pulling force by the exhaust fan 7, so that not only the low temperature second air but also the high temperature first Two airs with different temperatures are mixed so that one air can be drawn in. And about the 3rd duct part 82c and the 4th duct part 82d with which the pulling force of the exhaust fan 7 is weak, the opening area of an inlet port is made small and the flow volume of the inflowing high temperature 1st air is restrict | squeezed. In addition, the height of the third and fourth air guide wall portions 83c and 83d is increased to create an environment in which the flow path is earned and the temperature can be easily lowered. Further, the high-temperature first air exhausted from the third duct part 82c and the fourth duct part 82d is diffused while going to the exhaust fan, and is exhausted in a wide area of the upper half of the exhaust fan 7. Thus, a device for reducing the amount of heat per unit area has been devised. As a result, it is possible to exhaust the hot air outside the apparatus with a uniform temperature distribution without causing a large deviation in the temperature distribution of the air exhausted from the exhaust fan 7.

Note that the flow rate of the first air flowing through each duct portion depends on the opening area of the intake port of each duct portion and the position of the light source exhaust port 152 and the edge of the housing exhaust port 70a on the side farther from the exhaust fan (left side in the figure). Can be adjusted. Specifically, when it is desired to increase the flow rate of the first air flowing through the first and second duct parts, the opening area of the inlet of the first and second duct parts is increased, or the third and fourth ducts are increased. Or throttle the opening area of the air intake. Further, the positions of the edges of the light source exhaust port 152 and the housing exhaust port 70a on the side farther from the exhaust fan (left side in the figure) may be closer to the exhaust fan. By carrying out like this, the 1st air which flows in into the inflow part 85 can be made into an exhaust fan side, and can make 1st air flow easily to a 1st, 2nd duct part. Thereby, the flow volume of the 1st air sent to a 1st, 2nd duct part can be increased.
Also, if you want to increase the flow rate of the first air flowing through the third and fourth duct parts, conversely to the above, constricting the intake ports of the first and second duct parts, Widen the air intake. Further, the positions of the edges of the light source exhaust port 152 and the housing exhaust port 70a on the side farther from the exhaust fan (left side in the figure) are moved away from the exhaust fan.

  Moreover, in this embodiment, although the two duct parts (1st, 2nd duct parts) into which 1st air and 2nd air flow are provided, 1st air and 2nd air flow in. One duct portion may be provided, or three or more duct portions may be provided. Moreover, although two duct parts (third and fourth duct parts) into which only the first air flows are provided, only one duct part into which only the first air flows may be provided, or three or more duct parts may be provided. Good.

  Further, in this embodiment, the opening area of the intake port is smaller as the duct part is farther from the exhaust fan 7, but the opening area of the intake port of the third duct part and the fourth duct part may be equal. In addition, when the first air hardly flows through the fourth duct portion, the opening area of the intake port of the fourth duct portion may be larger than the opening area of the intake port of the third duct portion. However, even in such a configuration, the opening area of the intake port of the third duct portion and the fourth duct portion is made smaller than the opening area of the intake port of the first and second duct portions. In addition, for example, when most of the second air flows to the first duct part and hardly flows to the second duct part, the opening area of the inlet of the second duct part is set to the opening area of the inlet of the first duct part. May be equal or larger.

  In this embodiment, the length of the duct portion becomes longer as the distance from the exhaust fan increases. However, the third and fourth duct portions may be longer than the first and second duct portions. The length of the part and the fourth duct part may be the same. The lengths of the first duct part and the second duct part may be the same.

  A plurality of substrates are arranged in the housing. Specifically, an operation board for controlling an operation unit operated by a user, a connection circuit board for controlling connection with an external device such as a personal computer, and supplying stable power (current, voltage) to the light source 160. A ballast substrate that is a light source driving circuit substrate for driving the light source, a control substrate that controls the entire projector, a power supply circuit substrate that supplies power to each substrate in the apparatus, and the like are disposed. On these substrates, electrical elements such as coils, capacitors, and resistors are mounted. Among these electric elements, there are electric elements that generate a large amount of heat or have a low rated temperature, and there are electric elements that have a rated temperature or higher if they are not cooled. In particular, in order to apply a high voltage of 380 V at the maximum to the light source, a power supply circuit board having a circuit for raising the temperature of the commercial power supply (100 V) to 380 V at the maximum, or a light source to which a voltage of 380 V at the maximum is supplied. An electric element that generates a large amount of heat and easily reaches the rated temperature is mounted on the ballast substrate to be driven.

  Usually, a substrate on which an electric element that may reach the rated temperature if not cooled is cooled by air cooling. However, when a projector is used in a quiet environment such as a home theater, the wind noise of the fan becomes noise, so it is necessary to suppress the number of fans and the number of rotations of the fan. In the present embodiment, in order to reduce the noise of the projector, the cooling air for cooling the substrate is generated only by the suction force of the exhaust fan 7 to cool the substrate. In order to reduce the noise, it is preferable to suppress the rotational speed of the exhaust fan as much as possible. Further, if the exhaust fan is made large, a large amount of air can be exhausted at a low rotation, the flow rate of the substrate cooling air can be increased, and the substrate can be cooled satisfactorily. However, this leads to an increase in the size of the apparatus due to an increase in the size of the exhaust fan. As a result, the portability of the projector may be hindered. In order to suppress an increase in the size of the exhaust fan and to suppress the number of revolutions of the exhaust fan so as to suppress the substrate satisfactorily, efficient cooling of the substrate is required. Therefore, in the present embodiment, the arrangement position of the substrate is devised so that the substrate can be efficiently cooled. Hereinafter, it demonstrates concretely using drawing.

  22A is a perspective view of the projector from which the upper sheet metal part 14a, the rear sheet metal part 14c, and the right sheet metal part 14e of the main body housing 14 are removed, as seen from the rear side, and FIG. FIG. 3 is a front perspective view showing the inside of the main body housing of the projector. FIG. 22C is a rear perspective view showing the inside of the main body of the projector with the mirror bracket 53 of the projection optical unit removed.

  In the present embodiment, the power supply unit 8 for supplying power to the control board and the ballast board is disposed above the light source unit 15. The power supply unit 8 includes a main power supply unit 8a having a main power supply circuit board and a sub power supply unit 8b having a sub power supply circuit board. As shown in FIG. 22A, the main power supply unit 8a is attached to the front sheet metal part 14b of the main body casing, and the sub power supply unit 8b is attached to the rear sheet metal part 14c of the main body casing. . In the present embodiment, the main power supply unit 8a and the sub power supply unit 8b are attached at positions that do not face the air suction port of the exhaust fan 7. As a result, the main power supply unit 8a and the sub power supply unit 8b can suppress the intake air of the exhaust fan 7 and suppress the rotation speed of the exhaust fan to obtain a desired exhaust amount. As a result, the number of rotations of the exhaust fan can be suppressed, and the heat generating components in the main body housing such as the light source can be cooled.

  Further, a light source driving unit 12 including a ballast substrate as a light source driving circuit substrate is attached to a surface of the main body casing facing the projection optical unit 2 of the front sheet metal portion 14b. Further, as shown in FIG. 22C, a resin plate 170 is provided so as to partition the projection optical unit 2 and the power supply unit 8 arrangement space.

FIG. 23 is a block diagram of power supply.
As shown in FIG. 23, the sub power supply circuit board 80b included in the sub power supply unit 8b converts the AC voltage supplied from the power switch 182, the PFC switch unit 183, and the power cable 190 into a DC voltage, and controls the control board 200. Has a starting voltage converter 184 for supplying a DC voltage of 3.3V.

  The main power supply circuit board 80a included in the main power supply unit 8a has a control voltage conversion unit for converting the AC voltage supplied from the power cable 190 into a DC voltage and supplying the control board 200 with a DC voltage of 12V. 185. In addition, the ballast switch unit 186, the transformer unit 187 that changes the AC voltage of 100V to a predetermined voltage, the AC voltage adjusted by the transformer unit 187 is converted into a DC voltage, and a predetermined DC voltage is applied to the ballast substrate 12a. And a ballast voltage converter 188 for supply. In the present embodiment, the voltage is adjusted to 80 V to 380 V by the transformer 187, and the circuit constituting the transformer 187 includes a field effect transistor (FET) 284 (see FIG. 26) as an electrical element. ing.

  When the plug of the power cable 190 is inserted into the outlet, the power switch 182 is turned on, and an AC voltage is applied to the sub power circuit board 80b, a 3.3V DC voltage is applied from the starting voltage converter 184 to the control board 200. Applied. When a DC voltage of 3.3 V is applied to the control board 200, for example, the temperature detected by temperature detecting means such as a thermistor provided at a predetermined position of the device is checked, and the device is in a normal state. If it is determined that there is, the PFC switch unit 183 of the sub power circuit board 80b is turned on.

  When the PFC switch unit 183 is turned on, the AC voltage from the power cable 190 is supplied to the main power circuit board 80a. When an AC voltage is supplied to the main power supply circuit board 80a, a DC voltage of 12V is applied from the control voltage converter 185 to the control board 200. When a DC voltage of 12 V is applied, the control board 200 checks the temperature of the light source 160, for example, and turns on the ballast switch unit 186 of the main power supply circuit board 80a if there is no abnormality in the light source 160 or the like.

  When the ballast switch unit 186 of the main power circuit board 80a is turned on, an AC voltage from the power cable 190 is applied to the transformer unit 187, and the AC voltage is boosted to 380V by the transformer unit 187. Next, it is converted into a DC voltage by the ballast voltage converter 188 and supplied to the ballast substrate 12a. Then, the ballast substrate 12 a is controlled so that stable power (current / voltage) is supplied to the light source 160, and a DC voltage of 380 V is applied to the light source 160. As a result, the light source is turned on. After the light source is turned on, the transformer 187 is controlled by the controller 121 of the ballast substrate 12a, and the transformer 187 supplies the AC voltage adjusted to 80 to 90V to the ballast voltage converter 188. Then, as described above, after being converted into a DC voltage by the ballast voltage converter 188, the ballast substrate 12a is controlled so that stable power (current / voltage) is supplied to the light source. For example, when the rated power of the light source is 270 W, a voltage of 80 to 90 V and a current of 3.0 A to 3.4 A are supplied to the light source.

FIG. 24 is a perspective view showing the front sheet metal part 14b and the light source drive unit 12, and FIG. 25 is a side view showing the optical engine part 100 and the light source drive unit 12.
As shown in FIG. 24, the light source drive unit 12 is a light source drive circuit board, and includes a ballast board 12a that is a power stabilization circuit board and a ballast holder 13 that holds the ballast board 12a. The ballast holder 13 includes a substrate attachment portion 13a to which the ballast substrate 12a is attached, and a fixing portion 13b that extends rearward from the lower end of the substrate attachment portion 13a.

  The front sheet metal portion 14b has an upper surface portion 114a that protrudes to the front side compared to the lower surface portion 114b. The board mounting portion 13a of the ballast holder 13 is screwed to the upper surface portion 114a of the front sheet metal portion 14b and fixed to the step surface portion 114c orthogonal to the vertical direction connecting the upper surface portion 114a and the lower surface portion 114b of the front sheet metal portion 14b. The part 13b is screwed.

  Further, the four corners of the substrate attachment portion 13a of the ballast holder 13 are provided with screwing portions 113a extending rearward with respect to the substrate attachment portion 13a. Accordingly, as shown in FIG. 25, the ballast substrate 12a is screwed to the substrate attachment portion 13a with a predetermined gap J with respect to the substrate attachment portion 13a.

  Of the electric elements mounted on the ballast substrate 12a, the electric element 112b that reaches the rated temperature early is attached with a heat sink 112a, and the heat of the electric element 112b is dissipated by the heat sink 112a, The electric element 112b is prevented from reaching the rated temperature. Moreover, when the ballast board | substrate 12a is attached to the ballast holder 13, the heat sink 112a is arrange | positioned so that it may be located in the uppermost part of a board | substrate. As shown in FIG. 25A, when the ballast substrate 12a is attached to the ballast holder 13, the gap between the upper portion of the ballast substrate 12a and the back side of the concave mirror (free mirror bracket 6) is the narrowest portion, and the narrow portion The heat radiating plate 112a is disposed on the surface. The flow rate of air increases when flowing from a large space into a narrow space. Therefore, the substrate cooling air taken in from the first intake port 10a having a large opening area has a high flow velocity when passing through the narrow space surrounded by A in FIG. Thereby, the flow of the substrate cooling air passing through the surface of the heat radiating plate 112a can be accelerated, the heat radiating plate 112a can be well cooled by the substrate cooling air, and the heat radiating efficiency of the heat radiating plate 112a can be enhanced. Thereby, the heat of the electric element 112b that reaches the rated temperature early can be radiated well by the heat radiating plate 112a, and the electric element 112b can be prevented from reaching the rated temperature or more.

  Further, as shown in FIG. 22 (c), the concave mirror 5 reflects the incident projection image obliquely rearward and upward, so that the lower side is positioned closer to the inside of the housing than the upper side. Inclined with respect to the vertical direction. Further, the free mirror bracket 6 that holds the concave mirror 5 has a concave shape that follows the curvature of the back surface of the concave mirror 5 in FIG. Are attached to the mirror bracket 53. As a result, there is a large dead space between the lower part of the concave mirror (free mirror bracket 6) and the front sheet metal part 14b (precisely, the upper surface part 114a of the front sheet metal part) parallel to the vertical direction. A space is created. Since such a large dead space is open, the cooling air taken in from the first air inlet 10a (see FIGS. 2B and 2C) provided in the right sheet metal part 14e is transferred to the front sheet metal part. It tends to flow in the gap between 14b and the back side of the concave mirror.

  In the present embodiment, the light source drive unit 12 has a large dead space between the lower part of the concave mirror (free mirror bracket 6) and the front sheet metal part 14b (more precisely, the upper surface part 114a of the front sheet metal part). It is arranged in a space (gap). By disposing the light source driving unit 12 in such a large dead space where the cooling air easily flows, it is possible to suppress the increase in size of the apparatus and cool the ballast substrate 12a of the light source driving unit 12 satisfactorily.

  Further, as shown in FIG. 24, four main power supply unit fixing portions 114d provided to be inclined with respect to the upper surface portion 114a are provided on the upper surface portion 114a of the front sheet metal portion 14b.

FIG. 26 is a perspective view showing the front sheet metal part 14b and the main power supply unit 8a.
As shown in FIG. 26, the main power supply unit 8a has a main power supply circuit board 80a and a main power supply holder 16 to which the main power supply circuit board 80a is attached. The main power supply holder 16 is screwed to the main power supply unit fixing part 114d provided on the upper surface part 114a of the front sheet metal part 14b, so that the main power supply unit 8a is attached to the front sheet metal part 14b. A coil 281, a capacitor 282, and a transformer 283 are mounted on the front surface of the main power supply circuit board 80 a. A field effect transistor (FET) 284 is mounted on the back surface of the main power circuit board 80a. The main body of the field effect transistor 284 is fixed to a heat radiating plate 285 facing the back surface of the main power circuit board 80a with a predetermined gap. Since the heat radiating plate 285 is fixed to the field effect transistor 284 mounted on the circuit constituting the transformer 187 that may reach the rated temperature at an early stage, the heat of the field effect transistor 284 is dissipated by the heat radiating plate 285, The field effect transistor 284 is prevented from reaching the rated temperature.

  The main power supply holder 16 holds the main power supply circuit board 80a. Further, the heat sink 285 is held by the main power supply holder 16 so as to face the back surface of the main power supply circuit board 80a with a predetermined gap.

FIG. 27 is a diagram for explaining the inclination of the main power supply circuit board.
The main power circuit board 80a is attached to the front sheet metal part 14b in a state of being inclined with respect to the upper surface part 114a of the front sheet metal part 14b. Specifically, as shown in FIG. 27, the front metal plate 80a is arranged so that the board surface of the main power circuit board 80a is substantially parallel to the tangent line F of the free mirror bracket 6 passing through the rotation center O3 of the exhaust fan 7. It is attached to be inclined with respect to the upper surface portion 114a of the portion 14b.
Further, the cross-sectional area G between the resin plate 170 and the main power supply circuit board 80a is smaller than the cross-sectional area of the first air inlet 10a (see FIGS. 2B and 2C).

  FIG. 28 is a view showing the flow of the substrate cooling air in the main body, and FIG. 29 is a sectional view taken along the line KK of FIG. Due to the suction force of the exhaust fan 7, outside air is taken in from the first air inlet 10 a and the second air inlet 10 b provided in the main body housing 14 shown in FIGS. 2 (b) and 2 (c). The first air inlet 10a is provided on the front side (concave mirror side) with respect to the central portion in the front-rear direction of the right sheet metal portion 14e. Therefore, the outside air taken in from the first air inlet 10a flows into the first substrate cooling flow path R1 configured by a gap between the back side of the concave mirror 5 and the front sheet metal part 14b. Also, outside air taken in from the vicinity of the front end of the second air inlet 10b and the operation opening 18 flows along the right side surface of the optical engine unit, and then flows into the first substrate cooling channel R1.

  The second air inlet 10b, the operation opening 18, and the third air inlet 10c extend to the vicinity of the rear end of the right sheet metal portion 14e, and the opening near the rear end of the third air inlet 10c is formed. It is getting bigger. The outside air taken in from the vicinity of the rear end of the second intake port 10b, the operation opening 18, and the third intake port 10c is a second substrate configured by a gap between the projection optical unit and the rear sheet metal part 14c. It flows into the cooling channel R2.

  As shown in FIG. 25, since the first substrate cooling channel R1 is wider than the second substrate cooling channel R2, the suction force of the exhaust fan 7 is greater than that of the second substrate cooling channel R2. It acts on R1 strongly. Further, as shown in FIG. 2 (c), the first intake port 10a having a large opening area is provided on the concave mirror 5 side with respect to the center of the right side sheet metal part 14e (dashed line in the figure). The total opening area of the intake port is larger on the concave mirror side of the right sheet metal part 14e. Therefore, a lot of air is taken into the first substrate cooling channel R1 and flows into the first substrate cooling channel R1. As a result, the flow rate of the substrate cooling air is higher in the first substrate cooling flow path R1 than in the second substrate cooling flow path R2.

  In the present embodiment, the light source driving unit 12 including the ballast substrate 12a on which the electric element 112b that may reach the rated temperature of the element at an early stage is mounted in the first substrate cooling flow path R1 having a large flow rate. A main power supply circuit board 80a having a field effect transistor 284 mounted on a circuit constituting the transformer 187 that may reach the rated temperature is disposed. Thereby, the ballast board | substrate 12a and the main power supply circuit board 80a can be cooled favorably, and it can suppress that the electric element 112b and the field effect transistor 284 become more than rated temperature.

  Further, as described above, the ballast substrate 12a is screwed to the substrate attachment portion 13a with a predetermined gap J with respect to the substrate attachment portion 13a of the ballast holder 13. Thereby, as shown in FIG. 29, a part of the outside air taken in from the first air inlet 10a or the like flows into the gap J. Thereby, the back surface of the ballast substrate 12a (the surface opposite to the electric element mounting surface) can be air-cooled, and the ballast substrate 12a can be further air-cooled.

  As shown in FIG. 28, the substrate cooling air that has flowed into the first substrate cooling flow path R 1 flows along the curved shape of the free mirror bracket 6, and the power supply unit 8 is arranged by the suction force of the exhaust fan 7. Flow into the space. The substrate cooling air that has flowed into the second substrate cooling flow path R <b> 2 flows along the mirror bracket 53 of the projection optical unit, and then flows into the space where the power supply unit 8 is disposed by the suction force of the exhaust fan 7.

  In the present embodiment, a resin plate 170 that partitions the space in which the power supply unit 8 is disposed from the projection optical unit 2 is provided. By providing this resin plate 170, the influence of the suction force of the exhaust fan 7 does not act in a region T surrounded by a circle around the upstream side of the exhaust fan 7 of the resin plate 170 in the exhaust direction. As a result, the substrate cooling air that has flowed into the first substrate cooling flow path R1 does not flow along the curved shape of the free mirror bracket 6 to the downstream end T1 of the free mirror bracket 6 in the air flow direction. Also on the upstream side, the air flows along the main power circuit board 80a by the suction force of the exhaust fan 7. As a result, as shown by the chain line in FIG. 28, air that flows away from the main power supply circuit board 80a can be suppressed, and the first substrate cooling flow path R1 extends along the main power supply circuit board 80a. It becomes a flowing channel. As a result, the main power supply circuit board 80a can be cooled well.

  Part of the substrate cooling air that has flowed to the main power supply circuit board 80a flows along the front surface of the main power supply circuit board 80a, and a coil 281, a capacitor 282, a transformer mounted on the front face 283 and the like are cooled. Further, the remaining air for cooling the substrate flows in a gap between the back surface of the main power circuit board 80a and the heat sink 285. The back surface of the main electric circuit board 80a, the heat radiation plate 285, and the field effect transistor 284 can be cooled by the substrate cooling air that flows in the gap between the back surface of the main power supply circuit board 80a and the heat radiation plate 285. The air flowing along the main power supply circuit board is exhausted to the outside by the exhaust fan 7.

  The air flowing through the second substrate cooling flow path R2 flows along the sub power supply circuit board 80b, cools the sub power supply circuit board 80b, and is then exhausted outside the apparatus by the exhaust fan 7.

  In the present embodiment, the main power supply circuit board 80a is provided with a transformer 187, and a field effect transistor 284 mounted on a circuit constituting the transformer 187 is provided on the power supply circuit board (main and sub power supply circuit boards). It is the electrical element that reaches the rated temperature earliest among the mounted electrical elements. In this way, the main power supply circuit board 80a including the transformer 187 having the field effect transistor 284 that is the electric element that reaches the rated temperature earliest among the power supply circuit boards is used as the first substrate cooling flow path R1 having a large air flow rate. Is arranged. Thereby, main power supply circuit board 80a can be cooled well, and field effect transistor 284 can be prevented from reaching the rated temperature.

  Further, in the present embodiment, a heat radiating plate 285 for releasing the heat of the field effect transistor 284 is provided at a predetermined distance from the back surface of the main power supply circuit board 80a. Then, substrate cooling air is poured into a narrow gap between the back surface of the main power supply circuit board 80a and the heat radiating plate 285 to cool the field effect transistor 284 in air. As described above, since the flow rate of air increases when passing through a narrow space, the flow rate of the substrate cooling air flowing into the narrow gap between the back surface of the main power supply circuit board 80a and the heat radiating plate 285 increases. As a result, the heat sink 285 and the field effect transistor 284 can be satisfactorily cooled by the substrate cooling air, and the field effect transistor 284 can be prevented from reaching the rated temperature.

  In the present embodiment, the heat radiating plate 285 has the same size as the main power supply circuit board 80a. Thereby, the heat of the field effect transistor can be dissipated over a wide area, and the temperature rise of the field effect transistor can be satisfactorily suppressed. Further, the main body of the field effect transistor is separated from the back surface of the main power circuit board. Thereby, it is possible to suppress the heat of the electric elements such as the coil 281 and the capacitor 282 mounted on the front surface of the main power supply circuit board 80a from moving to the main body of the field effect transistor 284 through the board. it can. As a result, the temperature rise of the field effect transistor 284 can be suppressed.

  A field effect transistor 284 is mounted on the lower side of the main power supply circuit board 80a. Under the main power supply circuit board 80a, the substrate cooling air that has flowed into a large dead space (gap) between the lower part of the concave mirror (free mirror bracket 6) and the front sheet metal part 14b flows. The flow rate is high. Therefore, the field effect transistor 284 can be air-cooled satisfactorily.

  Further, the field effect transistor 284 may be mounted on the upper side of the main power supply circuit board 80a. As shown in FIG. 24, since the light source driving unit 12 is attached to the lower side of the upper surface portion 114a of the front sheet metal portion 14b, the air flowing above the main power circuit board 80a is heated by the heat of the ballast substrate 21a. Low temperature air that has not risen flows. Therefore, by mounting the field effect transistor 284, which is an electrical element that easily reaches the rated temperature, on the upper side of the main power supply circuit board 80a, the field effect transistor 284 can be used with the substrate cooling air that does not rise in temperature due to the heat of the ballast board 21a. Can be cooled.

  On the other hand, the sub power circuit board 80b includes only the starting voltage converter 184 for supplying a DC voltage of 3.3V, and the amount of heat generated by the electric elements is relatively small, and the rated temperature is hardly reached. Therefore, even if the sub power circuit board is disposed on the side where the flow rate is low, the electric elements of the sub power circuit board can be cooled well. Thereby, each power supply circuit board of the power supply unit 8 can be efficiently cooled, and even if the flow rate of the board cooling air flowing in the housing is reduced, each power supply circuit board of the good power supply unit 8 can be cooled. it can. Therefore, the rotation speed of the exhaust fan 7 can be suppressed without using the large exhaust fan 7, the noise of the apparatus can be suppressed, and the increase in the size of the apparatus can be suppressed. Moreover, each power supply circuit board of the power supply unit 8 can be efficiently cooled only by the intake of the exhaust fan 7, the number of parts can be reduced, and the cost of the apparatus can be reduced.

  In the present embodiment, as shown in FIG. 27, the board surface of the main power supply circuit board 80a is substantially parallel to the tangent line F of the free mirror bracket 6 passing through the rotation center O3 of the exhaust fan 7. As described above, the front sheet metal part 14b is attached to be inclined with respect to the upper surface part 114a. The substrate cooling air in the first substrate cooling flow path R <b> 1 flowing into the space where the power supply unit 8 is disposed flows toward the rotation center O <b> 3 of the exhaust fan 7 by the suction force of the exhaust fan 7. For this reason, in this embodiment, the board surface of the main power supply circuit board 80a is substantially parallel to the tangent line F of the free mirror bracket 6 passing through the rotation center O3 of the exhaust fan 7. Thereby, the main power supply circuit board 80a can be arranged along the flow direction of the air flowing along the curved shape of the free mirror bracket 6 of the first substrate cooling flow path R1. As a result, it is possible to flow through the main power circuit board 80a without reducing the air flow rate. Therefore, the main power supply circuit board 80a can be efficiently air-cooled, and the main power supply circuit board 80a can be satisfactorily cooled even if the rotational speed of the exhaust fan 7 is reduced or the number of fans is reduced. Therefore, the noise of the device can be reduced.

  Furthermore, in this embodiment, as shown in FIG. 27, the cross-sectional area G between the resin plate 170 that is the outlet of the flow path that flows along the curved shape of the free mirror bracket 6 and the main power supply circuit board 80a. However, it is smaller than the cross-sectional area of the first intake port 10a as the suction port of the first substrate cooling channel R1. Thereby, the flow rate when the substrate cooling air in the first substrate cooling flow path R1 passes through the gap between the resin plate 170 and the main power circuit board 80a can be increased. As a result, the flow velocity flowing along the main power circuit board 80a can be increased, and the main power circuit board 80a can be efficiently cooled.

  In the present embodiment, the sub power circuit board is disposed in the second substrate cooling flow path R2 having a small flow rate. However, instead of the sub power circuit board, an operation board and control board for controlling the operation panel are provided. A connection circuit board for controlling connection with an external device such as 200 or a personal computer may be arranged. Further, the positions of the main power supply circuit board 80a and the ballast board 12a may be changed. Further, the main ballast substrate including the electric element 112b that is divided into two ballast substrates 12a and cooled by the heat radiating plate 112a is disposed on the first substrate cooling channel R1 side, and the sub ballast substrate is replaced with the second substrate. You may arrange | position to the cooling flow path R2 side.

  Further, in the present embodiment, the exhaust fan 7 is provided on the left side surface of the main body housing, and the exhaust direction of the exhaust fan 7 is substantially the same as the projection direction of the projection image projected from the dust-proof glass 51 (backward obliquely upward). The directions are orthogonal. As described above, since the air after cooling the substrate and the light source is exhausted from the exhaust fan 7, air having a temperature higher than that of the outside air is exhausted. For example, when the exhaust fan 7 is provided on the rear sheet metal part 14c of the main body housing, the exhaust air may rise and cross the optical path of the projected image from the dustproof glass 51 to the projection surface S. The exhaust of the exhaust fan 7 is higher than the temperature of the surrounding air and has a low density. For this reason, the light passing through the periphery of the exhaust gas takes a path different from normal, and the projection image projected on the projection surface S is fluctuated like a hot flame. On the other hand, by setting the exhaust direction of the exhaust fan 7 to a direction substantially orthogonal to the projection direction of the projection image projected from the dust-proof glass 51 (backward and obliquely upward), even if the exhaust rises, the dust-proof The optical path of the projected image between the glass 51 and the projection surface S does not cross. As a result, it is possible to prevent fluctuations in the projected image projected on the projection surface S.

  In the present embodiment, the exhaust fan 7 is provided on the left side surface of the main body housing. However, it is only necessary that the exhaust of the exhaust fan does not cross the optical path of the projected image between the dustproof glass 51 and the projection surface S. . For example, it may be provided on the front sheet metal part 14b of the main body housing, and the exhaust direction of the exhaust fan may be the front.

  Further, in the present embodiment, an intake port is provided in the right sheet metal part 14e on the side where the optical engine unit 100 is disposed, and an exhaust fan is provided on the left side surface of the main body housing opposite to the side on which the optical engine unit 100 is disposed. 7 is provided. Thereby, the outside air taken in from each intake port flows along the outer peripheral surface of the projection optical unit 2, and the temperature rise of the projection optical unit 2 can be suppressed. As a result, thermal expansion of the projection optical system such as the concave mirror and the projection lens unit can be suppressed, and a good projection image can be maintained.

  Moreover, in this embodiment, since the light source drive unit 12 is attached to the front sheet metal part 14b, a part of the heat of the ballast substrate 12a is conducted to the front sheet metal part 14b and can be radiated from the front sheet metal part. The ballast substrate 12a can be cooled more effectively. Since the main power supply unit 8a is also attached to the front sheet metal part, part of the heat of the main power supply circuit board 80a can be conducted to the front sheet metal part 14b and radiated from the front sheet metal part, so that the main power supply can be more effectively The circuit board 80a can be cooled. Further, since the sub power circuit board 80b is attached to the rear sheet metal part 14c, part of the heat of the sub power circuit board 80b is conducted to the rear sheet metal part 14c and radiated from the rear sheet metal part. Therefore, the sub power circuit board 80b can be cooled more effectively.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect 1)
A light source 160, a concave mirror 5 that reflects an image formed using light from the light source 160 toward the projection plane S, an air blowing means such as an exhaust fan 7 that causes an air flow in the main body housing, and a main body An image projection apparatus comprising: a power circuit board such as a main power circuit board 80a that supplies power to an electrical component in a housing; and a light source driving circuit board such as a ballast board 12a that drives a light source. The light source drive circuit board is disposed to be inclined on the back surface of the concave mirror of the main body casing.
According to this, the air which has flowed through the back side of the concave mirror flows in a direction inclined with respect to the surface on the back side of the concave mirror of the main body casing. Therefore, the power circuit board or the light source driving circuit board is disposed on the back surface of the concave mirror of the main body casing so that the air flowing through the back surface of the concave mirror can be It flows along a light source driving circuit board such as a board. Thus, the air flowing through the concave mirror can be flowed to the power supply circuit board or the light source drive circuit board without reducing the flow velocity of the air. As a result, the power supply circuit board or the light source drive circuit board can be efficiently air-cooled, and the power supply circuit board or the light source can be satisfactorily reduced even if the rotational speed of the blowing means such as a fan is reduced or the number of fans is reduced The drive circuit board can be cooled. As a result, the noise of the apparatus can be reduced.

(Aspect 2)
In (Aspect 1), the body housing 14 is provided with an air inlet such as the first air inlet 10a for taking air into the housing, and an outlet portion of the flow path (in this embodiment, a resin plate) The cross-sectional area G of the flow path between 170 and the main power circuit board is made smaller than the cross-sectional area of the intake port.
According to this, the flow velocity of air increases when passing through a place where the cross-sectional area is narrow. Therefore, the flow rate of air can be increased when passing through the outlet portion of the flow path having a narrow cross-sectional area (in this embodiment, the flow path between the resin plate 170 and the main power supply circuit board 80a). Thereby, the flow velocity of the air flowing along the substrate can be increased, and the power supply circuit board or the light source driving circuit board can be effectively cooled.

(Aspect 3)
In (Aspect 1) or (Aspect 2), the air blowing means is an exhaust fan that exhausts air in a main body housing, and forms a flow path on the back side of the concave mirror that passes through the rotation center of the exhaust fan. The power supply circuit board or the drive circuit board was arranged in parallel with the tangent line of the shape flow path forming surface.
According to this, as described in the embodiment, the air that flows along the curve of the concave mirror on the back side of the concave mirror then flows toward the rotation center of the exhaust fan by the suction force of the exhaust fan. . Therefore, by arranging the power supply circuit board or the drive circuit board in parallel with the tangent line of the curved flow path forming surface that forms the flow path on the back side of the concave mirror passing through the rotation center of the exhaust fan, The power supply circuit board or the drive circuit board can be arranged along the flow of the air flow, and can flow to the power supply circuit board or the ballast circuit board without reducing the flow velocity of the air flowing through the back side of the concave mirror. The power circuit board or the light source driving circuit board can be effectively cooled.

(Aspect 4)
In (Aspect 3), the curved flow path forming surface is a facing surface portion facing the back surface of the concave mirror or the back surface of the concave mirror of a holding member such as the free mirror bracket 6 that holds the concave mirror.
According to this, air can be flowed along the back surface of a concave mirror or the opposing surface part which opposes the back surface of the concave mirror of the holding member holding the said concave mirror.

DESCRIPTION OF SYMBOLS 1 Projector 2 Projection optical unit 3 Image formation part 4 Projection lens part 4a Focus lever 5 Concave mirror 6 Free mirror bracket 7 Exhaust fan 7a Rotating shaft part 8 Power supply unit 8a Main power supply unit 8b Sub power supply unit 10a First inlet 10b Second Air inlet 10c Third air inlet 12 Light source drive unit 12a Ballast substrate 13 Ballast holder 13a Substrate attachment portion 13b Fixed portion 14 Main body housing 14a Upper sheet metal portion 14b Front sheet metal portion 14c Rear sheet metal portion 14d Lower sheet metal portion 14e Right sheet metal portion 15 Light source unit 16 Main power supply holder 18 Operation opening 20 Illumination unit 21 Color wheel 21a Color motor 22 Light tunnel 23 Relay lens 24 Cylinder mirror 25 Concave mirror 26 Illumination bracket 27 OFF light plate 28 Cooling member 28b Whey Cover cover 29a Through hole 30 Light modulation part 33 Heat sink 34 Fixing member 41 Lens holder 51 Dust-proof glass 52 Folding mirror 53 Mirror bracket 53a Claw part 54 Base member 70 Light source housing 70a Housing exhaust port 70b Air intake port 70c Intake duct unit 70d Bottom surface 70e Attachment Part 71 light source blower 80 light source exhaust duct 80a main power circuit board 80b sub power circuit board 81 fan holding part 82 exhaust guide part 82a first duct part 82b second duct part 82c third duct part 82d fourth duct part 83a first guide Wind wall portion 83b Second wind guide wall portion 83c Third wind guide wall portion 84 Exhaust fan side wall portion 85 Inflow portion 86 Fan mounting portion 100 Optical engine portion 112a Heat radiating plate 112b Electric element 114a Upper surface portion 114b Lower surface portion 114c Stepped surface portion 14d Main power supply unit fixing part 141 Projection opening part 141f Light source attachment / detachment opening part 141g Recessed part 151 Light source housing 151a Upper surface part 151b Lower surface part 151c Light emitting side surface part 151d Case attachment part 151e Fitting protrusion 152 Light source exhaust port 153 Second light source Suction port 154 Connector 155a Positioning projection 156 Opening portion 157 Glass plate 158a Inlet port 158b Outlet port 158c Airflow direction plate 159 Explosion-proof mesh 160 Light source 161 Reflector 162 Light emitting tube 162a Light emitting portion 163 Electrode portion 163a Electrode terminal 170 Resin plate F Tangent G Cross section J Clearance O3 Exhaust fan rotation center R1 First substrate cooling channel R2 Second substrate cooling channel Z Texture surface S Projection surface

Japanese Patent No. 5664979

Claims (4)

A light source;
A concave mirror that reflects an image formed using light from the light source toward the projection surface;
A blowing means for generating an air flow in the main body housing;
A power circuit board for supplying power to the electrical components in the main body housing;
In an image projection apparatus comprising a light source driving circuit board for driving the light source,
The image projection apparatus, wherein the power supply circuit board or the light source drive circuit board is disposed on an inclined surface on a back surface side of the concave mirror of the main body casing. The image projection apparatus according to claim 1,
The main body housing is provided with an air inlet for taking air into the housing,
An image projection apparatus, wherein a cross-sectional area of an outlet portion of the flow path is narrower than a cross-sectional area of the intake port. In the image projection device according to claim 1 or 2,
The air blowing means is an exhaust fan for exhausting air in the main body housing,
The image is characterized in that the power supply circuit board or the drive circuit board is arranged in parallel to a tangent to a curved flow path forming surface that forms a flow path on the back side of the concave mirror, passing through the rotation center of the exhaust fan. Projection device. The image projection apparatus according to claim 3.
An image projection apparatus, wherein the curved flow path forming surface is a back surface of a concave mirror or a facing surface portion facing the back surface of the concave mirror of a holding member that holds the concave mirror.

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