JP2015004881A - Image projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image projection device that can suppress dust and dirt from being adhered to optical elements and suppress an increase in cost of the device.SOLUTION: The image projection device includes an image forming unit that forms an image by using light from a light source 61 and a plurality of optical elements, and a projection optical unit, such as a projection optical system that projects the image formed by the image forming unit on a projection surface by using the plurality of optical elements, where the projection optical unit has a raised member 131 as a dust collection member arranged around a folding mirror 41. By using the raised member having a plurality of raised bristles as the dust collection member, the raised bristles are rubbed with each other due to the vibration during the transport of the device or the air flowing through the raised bristles to cause frictional charge of the raised bristles, and thereby enabling electrostatic attraction of dust and dirt inside the projection optical unit.

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 a plurality of optical elements such as an image generation element and a lens. An image projection apparatus that projects and displays on a screen or the like through a projection optical unit including a plurality of optical elements such as a lens and a mirror is known.

  When dust or dust adheres to optical elements such as the lens, mirror, and image generating element, there is a problem that an image projected on a screen or the like deteriorates.

  Patent Document 1 discloses an image projection in which an electrostatic dust collecting member is disposed in the vicinity of a liquid crystal panel serving as an optical element, and dust and dirt are electrostatically adsorbed to suppress the adhesion of dust and dirt to the liquid crystal panel. An apparatus is described.

  However, in the image projection apparatus described in Patent Document 1, a voltage is applied to the electrostatic dust collecting member by a voltage generation circuit, thereby electrostatically charging the electrostatic dust collecting member and electrostatically adsorbing dust and dirt. Is. Therefore, a voltage generator for charging the electrostatic dust collecting member is required, and there is a problem that the cost of the apparatus is increased due to an increase in the number of parts.

  The present invention has been made in view of the above problems, and an object thereof is to provide an image projection apparatus capable of suppressing dust and dust from adhering to an optical element and suppressing an increase in cost of the apparatus. It is.

  In order to achieve the above object, an invention according to claim 1 is directed to an image forming unit that forms an image using light from a light source and a plurality of optical elements, and an image formed by the image forming unit to a plurality of optical elements. In an image projection apparatus including a projection optical unit that projects onto a projection surface using an element, and a dust collection member that electrically adsorbs dust and dirt in the apparatus, the dust collection member is not applied with a voltage. The apparatus is characterized in that dust and dust in the apparatus can be electrically adsorbed.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that a dust and dust adhere to an optical element, and can suppress the cost increase of an apparatus.

The perspective view which shows the projector and projection surface which concern on this embodiment. An optical path diagram from the projector to the projection surface. FIG. 2 is a schematic perspective view showing an internal configuration of a projector. The schematic perspective view of a light source device. The perspective view which shows the optical system components accommodated in the illumination part with other parts. The perspective view which looked at the illumination part, the projection lens part, and the image formation part from the A direction of FIG. The figure explaining the optical path of the light in an illumination part. The figure which shows the optical path from a 1st optical system to a projection surface. The perspective view which looked at the installation surface side of the projector. The perspective view which shows a 1st optical part with an illumination part and a light modulation part. The schematic diagram which showed the arrangement | positioning relationship of each part in an apparatus. The figure which shows the usage example of a projector. The figure which shows another example of use of a projector. Explanatory drawing explaining the flow of the air in a projector. The perspective view which shows a light modulation part, an illumination part, and an intake blower. The schematic diagram of the projector which provided the exhaust port in the surface facing the projection surface of an exterior cover. The schematic block diagram which shows the raising member in 2nd optics.

  Hereinafter, an embodiment of a projector as an image projection apparatus to which the present invention is applied will be described. FIG. 1 is a perspective view showing a projector 1 and a projection surface 101 such as a screen according to the present embodiment. In the following description, the normal direction of the projection plane 101 is the X direction, the short axis direction (vertical direction) of the projection plane is the Y direction, and the long axis direction (horizontal direction) of the projection plane 101 is the Z direction.

  The projector is a device that forms a projection image based on image data input from a personal computer or a video camera, and projects and displays the projection image P on a projection surface 101 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, a small and light projector 1 using a micro drive mirror device DMD (Digital Micro-mirror Device: registered trademark) has become widespread, and the projector 1 has been widely used not only in offices and schools but also at home. It is coming. 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 a large screen image (increasing the projection surface) and to make the “projection space required outside the projector” as small as possible. As will be described later, in the projector 1 according to the present embodiment, a transmission optical system such as a projection lens is set in parallel to the projection surface 101, and the light beam is turned back by a folding mirror, and then the light beam is projected to the projection surface 101 by a free-form curved mirror. And is configured to be enlarged and projected. With this configuration, it is possible to reduce the size of the optical engine unit in a vertical three-dimensional manner.

As shown in FIG. 1, a transmissive glass 51 from which a projection image P is emitted is provided on the upper surface of the projector 1, and the projection image P emitted from the transmissive glass 51 is projected onto a projection surface 101 such as a screen. .
Further, on the upper surface of the projector 1, an operation unit 83 is provided for the user to operate the projector 1. A focus lever 33 for adjusting the focus is provided on the side surface of the projector 1.

FIG. 2 is an optical path diagram from the projector 1 to the projection surface 101.
The DMD 12 that generates an image to be projected generates light by irradiating light from a light source (not shown) by the lighting unit 20 and modulating the light irradiated by the lighting unit 20. The image generated by the DMD 12 is projected onto the projection surface 101 via the first optical system 70 of the first optical unit 30, the folding mirror 41 of the second optical unit 40, and the curved mirror 42.

FIG. 3 is a schematic perspective view showing the internal configuration of the projector 1.
As shown in FIG. 3, the light modulation unit 10, the illumination unit 20, the first optical unit 30, and the second optical unit 40 are arranged side by side in the Y direction in the drawing in the direction parallel to the projection plane and the image plane of the projection image. Has been. A light source device 60 is arranged on the right side of the illumination unit 20 in the drawing.

  Note that reference numerals 32a1 and 32a2 shown in FIG. 3 are leg portions of the lens holder 32 of the first optical unit 30, and reference numeral 263 is a screwing unit for screwing the light modulation unit 10 to the illumination unit 20. .

  Next, the structure of each part will be described in detail.

First, the light source device 60 will be described.
FIG. 4 is a schematic perspective view of the light source device 60.
The light source device 60 has a light source bracket 62, and a light source 61 such as a halogen lamp, a metal halide lamp, or a high pressure mercury lamp is mounted on the light source bracket 62. Further, the light source bracket 62 is provided with a connector portion 62a that connects to a power connector connected to a power supply portion (not shown). The connector part 62 a is provided on one end side in the longitudinal direction (Z direction) of the light source device 60.

  A holder 64 as a holding member holding a reflector (not shown) is screwed to the light emitting side of the light source 61 above the light source bracket 62 (the other end in the longitudinal direction of the light source device 60). An exit window 63 is provided on the surface of the holder 64 opposite to the light source 61 arrangement side. The light emitted from the light source 61 is collected on the emission window 63 by a reflector (not shown) held by the holder 64 and emitted from the emission window 63.

  Further, light source positioning portions 64a1 and 64a2 are provided at both ends in the X direction of the upper surface of the holder 64 and the lower surface of the holder 64 in order to position the light source device 60 on the illumination bracket 26 (see FIG. 6) of the illumination unit 20. . The two light source positioning portions 64a1 and 64a2 provided on the lower surface of the holder 64 have a hole shape.

  Further, a light source air supply port 64 b into which air for cooling the light source 61 flows is provided on the side surface of the holder 64, and air heated by the heat of the light source 61 is exhausted on the upper surface of the holder 64. A light source exhaust port 64c is provided.

  The light source bracket 62 is provided with a handle 68 for picking up the light source device 60 by a user's finger when replacing the light source device 60. The handle portion 68 is attached to the light source bracket 62 so as to be rotatable at substantially the center portion of the connector portion 62a and the light source positioning portions 64a1 and 64a2 in the longitudinal direction of the light source bracket 62 (Z direction in the drawing). In addition to the illustrated shape, the handle portion 68 may have a shape that is moderate enough to be picked up by a fingertip.

Next, the illumination unit 20 will be described.
FIG. 5 is a perspective view showing the optical system parts housed in the illumination unit 20 together with other parts.
As shown in FIG. 5, 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, which are held by an illumination bracket 26. Yes. The illumination bracket 26 has a housing-like portion 261 in which the two relay lenses 23, the cylinder mirror 24, and the concave mirror 25 are accommodated. Of the four side portions of the housing-like portion 261, Only the right side in the figure has a side surface, and the other three surfaces are open. An OFF light plate 27 (see FIG. 6) is attached to the side opening on the back side in the X direction in the figure, and the side opening on the near side in the X direction in the figure is shown in any drawing. An uncovered cover member is attached. As a result, the two relay lenses 23, the cylinder mirror 24, and the concave mirror 25 housed in the housing-like portion 261 of the illumination bracket 26 are either the illumination bracket 26 or the OFF light plate 27 (see FIG. 6). It is covered with a cover member not shown in the drawing.

  Further, an irradiation through-hole 26d for exposing the DMD 12 is provided on the lower surface of the housing-like portion 261 of the illumination bracket 26.

  The lighting bracket 26 has three leg portions 29. These leg portions 29 are in contact with the base member 53 (see FIG. 9) of the projector 1 and support the weight of the first optical unit 30 and the second optical unit 40 that are stacked and fixed on the illumination bracket 26. Further, by providing the leg portion 29, a space for allowing air outside the apparatus to flow into the heat sink 13 (see FIG. 6) as a heat radiating means for radiating the heat of the DMD 12 of the light modulation portion 10 is formed.

  Note that reference numerals 32a3 and 32a4 shown in FIG. 5 are legs of the lens holder 32 of the first optical unit 30, and reference numeral 45a3 is a screwing part 45a3 of the second optical unit 40.

6 is a perspective view of the illumination unit 20, the projection lens unit 31, and the light modulation unit 10 as viewed from the direction A in FIG.
An upper surface 26b orthogonal to the Y direction in the figure is provided on the upper portion of the housing-like portion 261 of the illumination bracket 26. In the four corners of the upper surface 26b, through holes through which screws for screwing the first optical unit 30 pass are provided (in FIG. 6, the through holes 26c1 and 26c2 are shown, and the remaining holes are illustrated. The through hole is not shown). Further, positioning holes 26e1 and 26e2 for positioning the first optical unit 30 on the illumination unit 20 are provided adjacent to the through holes 26c1 and 26c2 on the near side in the X direction in the drawing. Of the two positioning holes provided on the near side in the X direction in the figure, the positioning hole 26e1 on the arrangement side of the color wheel 21 is a main reference for positioning and has a round hole shape. The positioning hole 26e2 on the side opposite to the arrangement side of the color wheel 21 is a secondary reference for positioning, and is a long hole extending in the Z direction. Further, the periphery of each through hole 26c1, 26c2 protrudes from the upper surface 26b of the illumination bracket 26, and serves as a positioning projection 26f for positioning the first optical unit 30 in the Y direction. When the positional accuracy in the Y direction is increased without providing the positioning protrusions 26f, it is necessary to increase the flatness of the entire upper surface of the illumination bracket 26, which increases the cost. On the other hand, by providing the positioning projection 26f, it is only necessary to increase the flatness of only the portion of the positioning projection 26f. Therefore, the cost can be reduced and the positional accuracy in the Y direction can be increased.

  In addition, a light shielding plate 262 into which the lower portion of the projection lens unit 31 is fitted is provided in the opening on the upper surface of the illumination bracket 26 to prevent light from entering the housing-like portion 261 from above.

  Further, between the through holes 26c1 and 26c2 on the upper surface 26b of the illumination bracket 26, as will be described later, the second optical unit 40 is cut out so as not to be an obstacle when screwed to the first optical unit 30. .

  At the end of the illumination bracket 26 on the color wheel 21 side (the front side in the Z direction in the figure), two light source positioning portions 64a1 and 64a2 provided on the light source bracket 62 side of the holder 64 are fitted in a protruding shape. Two light source positioned portions 26a1 and 26a2 are provided. Then, the two light source positioning portions 64a1 and 64a2 of the holder 64 are fitted into the two light source positioned portions 26a1 and 26a2 provided on the illumination bracket 26 of the illumination unit 20, so that the light source device 60 is provided with the illumination unit. Positioned and fixed to 20 (see FIG. 3).

  An illumination cover 28 is attached to the illumination bracket 26 so as to cover the color wheel 21 and the light tunnel 22.

FIG. 7 is a diagram illustrating an optical path L of light in the illumination unit 20.
The color wheel 21 has a disk shape and is fixed to the motor shaft 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. Light collected by a reflector (not shown) provided in the holder 64 of the light source device 60 passes through the emission window 63 and reaches the peripheral end of the color wheel 21. The light reaching 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 focused on the image generation surface of the DMD 12 to form an image.

Next, the light modulation unit 10 will be described.
As illustrated in FIG. 7, the light modulation unit 10 includes a DMD board 11 on which the DMD 12 is mounted. The DMD 12 is mounted on a socket 11 a provided on the DMD board 11 with an image generation surface on which micromirrors are arranged in a lattice shape facing upward. The DMD board 11 is provided with a drive circuit for driving the DMD mirror. A heat sink 13 is fixed to the rear surface of the DMD board 11 (the surface opposite to the surface on which the socket 11a is provided) as heat radiating means for radiating the heat of the DMD 12. The portion of the DMD board 11 where the DMD 12 is mounted penetrates, and the heat sink 13 is formed with a protrusion 13a that is inserted into a through hole (not shown). The tip of the protrusion 13a is planar. The protrusion 13a is inserted into a through hole (not shown), and the flat surface at the tip of the protrusion 13a is brought into contact with the back surface (the surface opposite to the image generation surface) of the DMD 12. A heat transfer sheet that can be elastically deformed is affixed to the flat portion or the place where the heat sink 13 on the back surface of the DMD 12 abuts to improve the adhesion between the flat portion of the protrusion 13a and the back surface of the DMD 12, thereby increasing the thermal conductivity. May be.

  When the light modulator 10 is screwed to the illumination bracket 26 (see FIG. 6), the heat sink 13 is pressed and fixed to the surface opposite to the surface on which the socket 11a of the DMD board 11 is provided by the fixing member 14. The

  Below, fixation of the illumination bracket 26 of the light modulation part 10 is demonstrated. First, the DMD 12 positions the light modulation unit 10 on the illumination bracket 26 so as to face the opening surface of the irradiation through hole 26d provided on the lower surface of the illumination bracket 26 of the illumination unit 20 shown in FIG. Next, a screw is inserted from the lower side in the drawing so as to pass through a through hole (not shown) provided in the fixing portion 14 a and the through hole 15 of the DMD board 11. Next, a screw is screwed into a screw hole provided in the lower surface of a screwing portion 263 (see FIG. 3) provided in the illumination bracket 26, and the light modulation unit 10 is fixed to the illumination bracket 26. Further, when screws are screwed into the screw fixing portions 263 provided on the illumination bracket 26, the fixing member 14 pushes the heat sink 13 toward the DMD board. Thereby, the heat sink 13 is pressed and fixed by the fixing member 14 to the surface opposite to the surface on which the socket 11a of the DMD board 11 is provided.

  As described above, the light modulation unit 10 is fixed to the illumination bracket 26, and the three legs 29 shown in FIG. 5 also support the weight of the light modulation unit 10.

  A plurality of movable micromirrors are arranged in a lattice pattern on the image generation surface of the DMD 12. 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 61 is reflected toward the first optical system 70 (see FIG. 2) as indicated by the arrow L2 in FIG. When it is “OFF”, the light from the light source 61 is reflected toward the OFF light plate 27 held on the side surface of the illumination bracket 26 shown in FIG. 6 (see arrow L1 in FIG. 7). 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 reflected toward the OFF light plate 27 (not shown) is absorbed as heat and cooled by the flow of outside air.

Next, the second optical unit 40 will be described.
FIG. 8 is a perspective view showing an optical path from the first optical system to the projection surface.
As shown in FIG. 8, the second optical unit 40 includes a folding mirror 41 and a concave curved mirror 42 that constitute the second optical system. The surface of the curved mirror 42 that reflects the light can be a spherical surface, a rotationally symmetric aspherical surface, a free curved surface shape, or the like.

  Further, as shown in FIG. 3, the second optical unit 40 also includes a transmission glass 51 for transmitting the image reflected from the curved mirror 42 and protecting the optical system components in the apparatus. The second optical unit 40 includes a mirror bracket 43 that holds the folding mirror 41 and the transmission glass 51. Further, a free mirror bracket 44 for holding the curved mirror 42 and a mirror holder 45 to which the mirror bracket 43 and the free mirror bracket 44 are attached are provided.

  The mirror bracket 43 is attached to the upper part of the mirror holder 45. The folding mirror 41 is held so as to close the opening of the inclined surface of the mirror bracket 43, and the transmission glass 51 is held so as to close the upper opening of the mirror bracket 43. A free mirror bracket 44 that holds the curved mirror 42 is attached to a mirror holder 45. The second optical unit 40 is stacked and fixed on the lens holder 32 of the first optical unit 30. Accordingly, the projection lens unit 31 is surrounded by the folding mirror 41, the curved mirror 42, the mirror bracket 43, the free mirror bracket 44, the mirror holder 45, and the transmission glass 51.

  A dust collecting member is provided around the folding mirror 41. In this embodiment, the raising member 131 which has a several raising is used as a dust collection member. The raising is made of an insulator, and the raising is rubbed and charged at the time of shipment from the factory. As a result, even if no voltage is applied, the dust and dirt in the second optical unit 40 are electrostatically adsorbed to the raised hair, and the dust and dirt adhere to the exit surface of the folding mirror 41, the curved mirror, and the projection lens unit 31. Can be suppressed. Thereby, the power supply device which applies a voltage to a dust collecting member becomes unnecessary, and the cost increase of an apparatus can be suppressed. In addition, by using a raised member as the dust collecting member, it is possible to widen the adsorption area where dust and dust are adsorbed, and it is possible to maintain good dust collecting performance over time.

  In addition, there is a risk that the triboelectric charge will decrease due to discharge over time. However, in the present embodiment, by using the raised members, the raised hairs are frictionally charged by, for example, vibration when the projector apparatus is carried or installed, or the raised hairs rub against each other due to the air flow in the second optical unit 40. Can be made. Thereby, the charging of the raised hair can be maintained over time, and dust and dirt in the second optical can be electrostatically adsorbed over time.

  Moreover, you may use the electret material which carried out the electric polarization permanently as a dust collection member. Even when the electret material is used, dust and dirt in the second optical can be electrostatically adsorbed without using a power supply device that applies a voltage to the dust collecting member, and the cost of the device can be suppressed. Further, it is preferable that the raising of the raising member is made of an electret material, so that the adsorption area to which dust and dust are adsorbed can be increased, and good dust collection performance can be maintained over time.

  In addition, as shown in FIG. 5, by arranging the raised member 131 in the vicinity of the folding mirror 41 that is an optical element, dust and dust adhering to the folding mirror 41 can be adsorbed. It is possible to satisfactorily suppress the adhesion of dust.

  In the present embodiment, the raised member 131 is disposed only in the vicinity of the folding mirror 41. However, the raised member 131 may be provided in the vicinity of the curved mirror 42 or in the vicinity of the projection lens unit 31. Thereby, dust adhering to the projection lens unit 31 and the curved mirror 42 can be adsorbed, which is preferable.

  As shown in FIG. 8, the light beam transmitted through the projection lens unit 31 constituting the first optical system 70 forms an intermediate image conjugate with the image generated by the DMD 12 between the folding mirror 41 and the curved mirror 42. To do. This intermediate image is formed as a curved surface image between the folding mirror 41 and the curved mirror 42. Next, the divergent light beam after forming the intermediate image is incident on the concave curved mirror 42 and becomes a convergent light beam. The curved mirror 42 converts the intermediate image into a “further enlarged image” on the projection surface 101. Projection images are formed.

  As described above, the projection optical system is configured by the first optical system 70 and the second optical system, and an intermediate image is formed between the first optical system 70 and the curved mirror 42 of the second optical system. By enlarging and projecting with the mirror 42, the projection distance can be shortened and it can be used even in a narrow conference room.

  In addition, the first optical unit 30 and the second optical unit 40 are stacked and fixed on the illumination bracket 26. Further, the light modulation unit 10 is also fixed. Therefore, the leg part 29 of the illumination bracket 26 is fixed to the base member 53 so as to support the weight of the first optical part 30, the second optical part 40 and the light modulation part 10.

  Since the light source 61 reaches the end of its life when used over time, it needs to be periodically replaced. For this reason, in this embodiment, the light source device 60 is detachably provided from the apparatus main body.

FIG. 9 is a perspective view of the projector 1 as viewed from the installation surface side.
As shown in FIG. 9, the base member 53 constituting the bottom surface of the projector 1 is provided with an opening / closing cover 54, and the opening / closing cover 54 is provided with a rotation operation portion 54 a. When the rotation operation unit 54a is rotated, the fixing of the opening / closing cover 54 and the apparatus main body is released, and the opening / closing cover 54 can be detached from the apparatus main body. Further, a first air inlet 92 is provided at a location facing the DMD 12 of the base member 53.

  Further, as shown in FIG. 9, on one YX plane of the exterior cover 59 of the projector 1, the second intake port 84 and an external input unit 88 to which image data from an external device such as a personal computer is input. Is provided

FIG. 10 is a perspective view showing the first optical unit 30 together with the illumination unit 20 and the light modulation unit 10.
As shown in FIG. 10, the projection lens unit 31 is provided with a focus gear 36, and the idler gear 35 is engaged with the focus gear 36. A lever gear 34 meshes with the idler gear 35, and a focus lever 33 is fixed to the rotation shaft of the lever gear 34. The tip portion of the focus lever 33 is exposed from the apparatus main body as shown in FIG.

  When the focus lever 33 is moved, the focus gear 36 is rotated via the lever gear 34 and the idler gear 35. When the focus gear 36 rotates, a plurality of lenses constituting the first optical system 70 in the projection lens unit 31 move in predetermined directions, and the focus of the projected image is adjusted.

  The idler gear 35 is provided in the gap between the lower surface of the curved mirror 42 and the lens holder 32 shown in FIG.

  FIG. 11 is a schematic diagram showing an arrangement relationship of each part in the apparatus. As illustrated in FIG. 11, the light modulation unit 10, the illumination unit 20, the first optical unit 30, and the second optical unit 40 are stacked in the Y direction, which is the minor axis direction of the projection surface. The light source device 60 is disposed in the Z direction, which is the major axis direction of the projection surface, with respect to the stacked body in which the light modulation unit 10, the illumination unit 20, the first optical unit 30, and the second optical unit 40 are stacked. Thus, in this embodiment, the light modulation unit 10, the illumination unit 20, the first optical unit 30, the second optical unit 40, and the light source unit are in a direction parallel to the projected image and the projection plane 101. Arranged side by side in the direction or Z direction. More specifically, the image forming unit composed of the light modulation unit 10 and the illumination unit 20 and the projection optical system composed of the first optical unit 30 and the second optical unit 40 are orthogonal to the stacked direction. In the direction, the light source device 60 is connected to the image forming unit. Further, the image forming unit and the light source device 60 are arranged on the same straight line parallel to the base member 53. The image forming unit and the projection optical system are arranged on the same straight line perpendicular to the base member 53, and are arranged in the order of the image forming unit and the projection optical system from the base member 53 side. Thereby, it can suppress that the installation space of an apparatus is taken in the direction orthogonal to the surface of the projection image projected on the projection surface 101. FIG. Accordingly, when the image projection apparatus is used on a desk or the like, the apparatus can be prevented from interfering with the arrangement of the desk or chair even in a small room.

  Further, in the present embodiment, a power supply device 80 for supplying power to the light source 61 and the DMD 11 is stacked above the light source device 60. The light source device 60, the power supply device 80, the image forming unit, and the projection optical system are housed in a housing of the projector 1 including the upper surface of the projector, the base member 53, and an exterior cover 59 that covers the periphery of the projector 1. Yes.

FIG. 12 is a diagram illustrating a usage example of the projector 1 of the present embodiment.
As shown in FIG. 12, when the projector 1 is used in, for example, a conference room, the projector 1 is used by placing the projector 1 on a table 100 and projecting an image onto a projection surface 101 such as a whiteboard. Further, as shown in FIG. 13, the projector 1 according to the present embodiment can be used by being suspended from the ceiling 105.

  In the present embodiment, the second optical system is configured by the folding mirror 41 and the curved mirror 42. However, the second optical system may be configured by only the curved mirror 42. The folding mirror 41 may be a plane mirror, a mirror having a positive refractive power, or a mirror having a negative refractive power. In this embodiment, a concave mirror is used as the curved mirror 42, but a convex mirror can also be used. In this case, the first optical system 70 is configured not to form an intermediate image between the first optical system 70 and the curved mirror 42.

FIG. 14 is an explanatory diagram for explaining the flow of air in the projector 1 according to the present embodiment. This figure is a diagram of the projector 1 viewed from a direction (X direction) orthogonal to the projection plane 101.
As shown in FIG. 14, a second intake port 84 that is open for taking air outside the apparatus into the projector 1 is provided on one of the side surfaces of the projector 1 (left side in the drawing). No intake fan is disposed at the second intake port 84. Further, an exhaust port 85 having an opening for exhausting air in the projector 1 is provided on the other side (right side in the drawing) of the side surface of the projector 1. An exhaust fan 86 is provided so as to face the exhaust port 85.

  A part of the exhaust port 85 and the second intake port 84 is provided so as to be between the light source device 60 and the operation unit 83 when the projector 1 is viewed from a direction (X direction) orthogonal to the projection plane 101. It has been. As a result, the air outside the apparatus taken in from the second intake port 84 can be removed from the gap between the lower surface of the curved mirror 42 and the lens holder 32 shown in FIG. 5 or from the mirror holder 45 of the second optical unit 40. It moves around the back surface of the ZY plane or the curved mirror 42 and moves toward the exhaust port 85 along the back surface of the mirror holder 45 or the curved mirror 42. Further, a part of the air outside the apparatus taken in from the second intake port 84 is further sucked into the light source blower 95 inside the casing and flows to the light source apparatus 60. When viewed from the Z direction in the figure, the power supply device 80 arranged on the upper portion of the light source device 60 has a shape in which the U-shaped light source device 60 side is opened due to the arrangement of three substrates.

  A part of the exhaust port 85 and the second intake port 84 is provided so as to be between the light source device 60 and the operation unit 83 when the projector 1 is viewed from a direction (X direction) orthogonal to the projection plane 101. Thus, the following effects can be obtained. That is, there is an effect that an air flow that passes between the light source device 60 and the operation unit 83 and is discharged from the exhaust port 85 can be generated.

  Further, a light source blower 95 is arranged at a location where air around a color motor 21a (see FIG. 5) for rotating the color wheel 21 of the illumination unit 20 can be sucked. Thereby, the color motor 21a can be cooled by the airflow generated by the intake of the light source blower 95.

  The air sucked by the light source blower 95 passes through the light source duct 96 and flows into the light source air inlet 64b (see FIG. 4) of the holder 64. Further, part of the air flowing into the light source duct 96 flows between the light source housing 97 and the exterior cover 59 from an opening 96 a formed on the surface of the light source duct 96 facing the exterior cover 59 (see FIG. 9). .

  The air flowing between the light source housing 97 and the exterior cover 59 from the opening 96 a of the light source duct 96 is discharged from the exhaust port 85 by the exhaust fan 86 after cooling the light source housing 97 and the exterior cover 59.

  The air that has flowed to the light source supply port 64 b flows into the light source 61, cools the light source 61, and is then exhausted from the light source exhaust port 64 c provided on the upper surface of the holder 64. The air exhausted from the light source exhaust port 64 c is exhausted from the opening on the upper surface of the light source housing 97 to the space surrounded by the power supply device 80. Thereafter, the low-temperature air that has entered the second optical unit 40 and flows into the space surrounded by the power supply device 80 is mixed with the low-temperature air, and is then discharged from the exhaust port 85 by the exhaust fan 86. As described above, the high-temperature air exhausted from the light source exhaust port 64 c is mixed with the air outside the apparatus taken in from the second intake port 84 and then exhausted, whereby the air exhausted from the exhaust port 85 is exhausted. It can suppress becoming high temperature.

  Moreover, it is preferable that the operation unit 83 operated by the user is provided on the upper surface of the apparatus so that the user can easily operate. However, in the present embodiment, since the transmissive glass 51 for projecting an image on the projection surface 101 is provided on the upper surface of the projector 1, the operation unit is located at a position overlapping the light source 61 when the projector is viewed from the Y direction. 83 must be provided.

  In the present embodiment, air that has flowed between the light source device 60 and the operation unit 83 from the air inlet 84 toward the air outlet 85 and has cooled the light source 61 to a high temperature is exhausted toward the air outlet. Therefore, it is possible to suppress the movement of the high-temperature air to the operation unit 83. Thereby, it is possible to suppress the temperature of the operation unit 83 from rising due to the air heated to a high temperature by cooling the light source 61. Further, a part of the air that flows around the second optical unit 40 from the intake port 84 and flows toward the exhaust port 85 passes right under the operation unit 83 to cool the operation unit 83. This can also suppress the temperature rise of the operation unit 83.

  In addition, air outside the apparatus is sucked from the power inlet 56 provided in the base member 53 shown in FIG. A ballast substrate (not shown) for supplying a stable power (current) to the light source 61 is disposed behind the light source housing 97 in the X direction in the drawing. Air outside the apparatus sucked from the power supply inlet 56 cools the ballast substrate while moving upward between the light source housing 97 and a ballast substrate (not shown). Then, after flowing into a space surrounded by the power supply device 80 disposed above the ballast substrate, the exhaust fan 86 exhausts the air from the exhaust port 85.

  A cooling unit 120 that cools the heat sink 13 of the light modulation unit 10, the light source bracket 62 of the light source device 60, and the like is disposed on the lower left side of the apparatus main body. The cooling unit 120 has an intake blower 91 and a horizontal duct 93. A first air inlet 92 is provided at a location of the base member 53 facing the air intake blower 91. With such a configuration, the intake blower 91 is disposed in the first intake port 92.

  As shown in FIG. 15, the intake blower 91 is a double-sided intake sirocco fan. The intake blower 91 is configured so that the base member-side blower intake port 91a of the intake blower 91 is opposed to the first intake port 92 provided in the base member 53 which is a facing surface portion facing the DMD 12 of the projector housing. Attached to the modulator 10. In addition, although the surface opposite to the base member side blower intake port 91a of the intake blower 91 is also an intake port, the intake amount of the base member side blower intake port 91a is larger. The heat sink 13 is formed of a first fin portion having a predetermined fin height and a second fin portion having a fin height higher than that of the first fin portion. The intake blower 91 is attached to the first fin portion so that the blower exhaust port 91 b of the intake blower 91 faces the second fin portion of the heat sink 13. By using the intake blower 91 as a double-sided intake sirocco fan, the first fin portion of the heat sink 13 can be efficiently cooled.

  As shown in FIG. 14, the horizontal duct 93 has an upper surface and a part of the lower surface opened, and the opening on the lower surface faces the first air inlet 92 provided in the base member 53. The horizontal duct 93 is fixed to the base member 53 of the projector 1. Further, the light modulation unit 10 is arranged on the horizontal duct 93 so that the heat sink 13 of the light modulation unit 10 and the intake blower 91 attached to the light modulation unit 10 pass through the opening on the upper surface of the horizontal duct.

  The intake blower 91 draws air outside the apparatus through the first intake opening 92 at the base member side blower intake opening 91a, and takes out the intake blower 91 from the blower exhaust opening 91b toward the second fin portion of the heat sink 13. Exhaust the air. Thereby, the 2nd fin part of the heat sink 13 is air-cooled. When the second fin portion of the heat sink 13 is air-cooled, the DMD 12 can be efficiently cooled, and the DMD 12 can be prevented from reaching a high temperature.

  As shown in FIG. 14, air is generated by the intake blower 91, and the air passing through the heat sink 13 moves through the horizontal duct 93 and passes through the light source bracket 62 of the light source device 60 shown in FIG. Flows into the portion 65 or the opening 65a. The air flowing into the opening 65a flows between the opening / closing cover 54 and the light source bracket 62, and cools the opening / closing cover 54.

  On the other hand, the air that has flowed into the passage portion 65 cools the light source bracket 62, then flows into the portion of the light source 61 opposite to the emission side, and cools the side of the light source 61 opposite to the reflecting surface of the reflector. Then, the reflector of the light source 61 is cooled. Therefore, the air passing through the passage portion 65 takes heat from both the light source bracket 62 and the light source 61. The air that has passed near the reflector passes through the exhaust duct 94 that guides the air from the height of the light source bracket 62 to the height near the bottom of the exhaust fan 86, and then merges with the air exhausted from the light source exhaust port 64C. The air is exhausted from the exhaust port 85 by the exhaust fan 86 through the guide 87. The air flowing between the opening / closing cover 54 and the light source bracket 62 through the opening 65 a cools the opening / closing cover 54, moves inside the apparatus, and is discharged from the exhaust port 85 by the exhaust fan 86. . Therefore, the flow path from the first intake port 92 to the exhaust port 85 does not include the vicinity of the gap between the lower surface of the curved mirror 42 and the lens holder 32.

  In the present embodiment, as described above, a gap is provided between the lower surface of the curved mirror 42 and the lens holder 32 in order to secure an arrangement space for the idler gear 35 that meshes with the focus gear 36 of the projection lens unit 31. . Because of such a gap, air enters and exits inside and outside the second optical unit 40. Therefore, a part of the air from outside the apparatus taken in from the second intake port 84 that moves toward the exhaust port 85 along the back surface of the mirror holder 45 or the curved mirror 42 is caused by the lower surface of the curved mirror 42 and the lens. It flows into the gap between the holder 32 and the holder 32. As a result, air flows into the second optical unit 40, and dust or other dust contained in the air from outside the apparatus may adhere to the curved mirror 42, the folding mirror 41, and the like.

  However, in the present embodiment, as shown in FIG. 17, a raised member 131 made of triboelectric charging or electret material is disposed in the second optical unit 40, and the raised member 131 is used for dust or the like. Dust is collected electrostatically. Thereby, it is possible to suppress dust and the like from adhering to the curved mirror 42 and the folding mirror 41, and it is possible to suppress quality deterioration of the projected image.

  Further, in the present embodiment, the first air inlet 92 is provided in the base member 53 which is a facing surface portion facing the DMD 12 of the projector casing. Thereby, the cooling air from the outside of the apparatus sucked from the first air inlet 92 flows directly into the heat sink 13. Therefore, the pressure loss until the cooling air reaches the heat sink 13 can be suppressed as compared with the configuration in which the cooling air taken from outside the apparatus flows into the heat sink 13 via the duct. As a result, the flow rate of air flowing into the exhaust port 85 via the heat sink 13 and the light source device 60 can be increased as compared with a configuration in which air outside the device flows into the heat sink 13 via the duct. Since the flow rate of the air exhausted from the exhaust port 85 by the exhaust fan 86 is constant, the air outside the apparatus taken in from the second intake port 84 by the exhaust fan 86 is increased by increasing the flow rate of the air after cooling the light source. The flow rate can be reduced. As a result, the flow rate of the air outside the apparatus that moves toward the second air intake port 84 along the vicinity of the gap between the lower surface of the curved mirror 42 and the lens holder 32 or along the back surface of the mirror holder 45 or the curved mirror 42 is increased. It is possible to suppress the air outside the apparatus from flowing into the second optical unit. Thereby, it is possible to further suppress the dust contained in the air outside the apparatus from adhering to the curved mirror 42 and the folding mirror 41 of the second optical unit 40. Thereby, a favorable projection image can be projected over a long period of time, and a highly reliable projector can be provided.

  Even in the configuration in which the air outside the apparatus flows into the DMD 12 via the duct, the flow rate of the DMD 12 flowing into the exhaust port 85 and the air after cooling the light source can be increased by increasing the rotational speed of the fan of the intake blower. . However, in this case, the wind noise of the fan of the intake blower 91 increases and becomes noise. In addition, there is a demerit that power consumption increases. On the other hand, in this embodiment, the flow rate of the cooled air after cooling the DMD 12 and the light source that flows into the exhaust port 85 can be increased without increasing the rotational speed of the fan of the intake blower. Thereby, an increase in noise and power consumption can be suppressed.

  Further, as shown in FIG. 14, when the projector is divided into two equal parts in the Z-axis direction in the figure and two equal parts in the Y-axis direction in the figure, and the project is divided into four regions S1 to S4, The exhaust port 85 is disposed in the region S3, and the light source device 60 is disposed in the region S4. As a result, the air outside the apparatus sucked from the first air inlet 92 is exhausted outside the apparatus in the order of S2 → S3 → S4 as shown in FIG. 14, and the second optical unit 40 is arranged. It is possible to prevent the region S1 from passing through. Thereby, the DMD 12 and the light source device 60 can be cooled without passing the air outside the apparatus sucked by the first air inlet 92 through the region where the second optical unit 40 is provided.

  Further, the exhaust port 85 may be in the region S3 shown in FIG. For example, as shown in FIG. 16, an exhaust port 85 is provided on a surface facing the projection surface 101 of the exterior cover 59 (a surface opposite to the surface on which the focus lever 33 is provided) and faces the exhaust port 85. An exhaust fan 86 may be provided on the surface.

  Further, the first air inlet 92 may be provided in a portion of the exterior cover 59 that faces the DMD 12. Even in such a configuration, the air outside the apparatus sucked in by the first air inlet 92 can be directly flowed to the DMD 12.

  In the present embodiment, the raised member 131 is provided in the second optical unit 40. However, the raised member 131 may be provided in the illumination unit 20, for example, in the vicinity of the DMD 12 that is an optical element. By adopting such a configuration, it is possible to suppress dust and dirt from adhering to optical elements such as the mirror part of the DMD 12 and the relay lens 23, the cylinder mirror 24, and the concave mirror 25 in the illumination part 20.

What has been described above is an example, and the present invention has a specific effect for each of the following aspects.
(Aspect 1)
An image forming unit that forms an image using light from the light source 61 and a plurality of optical elements, and a projection optical system that projects an image formed by the image forming unit onto a projection surface using the plurality of optical elements In an image projection apparatus including an optical unit and a dust collecting member that electrically adsorbs dust and dirt in the apparatus, the dust collecting member is electrically adsorbed to dust and dirt in the apparatus without applying a voltage. Configured to be possible.
According to the aspect 1, since the dust collecting member can electrically adsorb dust and dirt in the apparatus without applying a voltage, the cost of the apparatus can be reduced as compared with that charged using a voltage generation circuit. You can suppress the up. Further, dust and dirt in the apparatus are electrostatically attracted and collected by the dust collecting member, so that dust and dirt can be prevented from adhering to the optical element such as the folding mirror 41. Thereby, projection image degradation can be suppressed.
Note that, for example, the dust collecting member can be configured to be capable of electrically adsorbing dust or dust in the apparatus without applying a voltage by frictionally charging at the time of shipment from the factory. In addition, as described in aspect 2, the dust collecting member can be a raised member so that the dust and dirt in the apparatus can be electrically adsorbed. Moreover, even if an electret material that is permanently electrically polarized by a predetermined construction method is used as the dust collecting member, the dust collecting member can electrically adsorb dust and dust in the apparatus without applying a voltage. Can be configured.

(Aspect 2)
In (Aspect 1), a raising member having a plurality of raisings was used as the charging member.
In the configuration in which the charging member is frictionally charged at the time of shipment from the factory, there is a risk that the charge amount is reduced by natural discharge. However, by using a raised member having a plurality of raised parts as the dust collecting member, the raised parts rub against each other due to vibration during transportation of the apparatus or air flowing in the raised parts, and the raised parts are frictionally charged, and the dust collecting member is charged. Can be maintained. In addition, by making the dust collecting member a raised member having a plurality of raised parts, the adsorption area for adsorbing dust and dust can be expanded compared to dust collecting members with a smooth surface, and good dust collection performance over time Can be maintained.

(Aspect 3)
In (Aspect 1) or (Aspect 2), the dust collecting member is disposed in the vicinity of the optical element.
By providing such a configuration, dust and dirt adhering to the optical element such as the folding mirror 41 can be favorably adsorbed by the raised member 131, and it is possible to satisfactorily suppress the dust and dirt from adhering to the optical element. it can.

(Aspect 4)
In (Aspect 3), a projection optical unit such as a projection optical system includes, as optical elements, a projection lens unit 31 and a reflection mirror such as a folding mirror 41 that reflects an image emitted from the projection lens unit 31. A dust collecting member 131 is disposed in the vicinity of the reflecting mirror.
By providing such a configuration, it is possible to satisfactorily suppress dust and dirt from adhering to the reflection mirror such as the folding mirror 41.

(Aspect 5)
In any one of (Aspect 1) to (Aspect 4), an electret material is used as the dust collecting member.
With such a configuration, the charging member can be permanently charged, and dust and dirt can be favorably adhered over time.

1: Projector 10: Light modulator 11: DMD board 12: DMD
13: heat sink 20: illumination unit 30: first optical unit 40: second optical unit 41: folding mirror 42: curved mirror 53: base member 59: exterior cover 60: light source device 61: light source 80: power supply device 84: second Intake port 85: Exhaust port 86: Exhaust fan 91: Intake blower 91a: Blower intake port 91b: Blower exhaust port 92: First intake port 93: Horizontal duct 94: Exhaust duct 95: Light source blower 96: Light source duct 120: Cooling unit 131: Brushed member

Japanese Patent Laid-Open No. 2002-6283

Claims (5)

An image forming unit that forms an image using light from the light source and a plurality of optical elements;
A projection optical unit that projects an image formed by the image forming unit onto a projection surface using a plurality of optical elements; and
In the image projection apparatus provided with a dust collecting member that electrically adsorbs dust and dust in the apparatus,
An image projection apparatus, wherein the dust collecting member is configured to be capable of electrically adsorbing dust and dirt in the apparatus without applying a voltage. 2. The image projection apparatus according to claim 1, wherein a raised member having a plurality of raised portions is used as the dust collecting member. The image projection apparatus according to claim 1 or 2,
An image projection apparatus, wherein the dust collecting member is disposed in the vicinity of the optical element. The image projection apparatus according to claim 3.
The projection optical unit includes, as optical elements, a projection lens unit, and a reflection mirror that reflects an image emitted from the projection lens unit,
An image projection apparatus, wherein the dust collecting member is disposed in the vicinity of the reflecting mirror. In the image projection apparatus in any one of Claims 1 thru | or 4,
An image projection apparatus using an electret material as the dust collecting member.

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