JP2005316250A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of preventing the adhesion of dust to the reflection surface of a reflection mirror and scratch thereon, and further restraining the number of exchanging times of a transparent member with which an aperture is covered. <P>SOLUTION: The aperture part 6 formed on the upper part of a housing 5 is covered with a part of flexible long-length film 8 transmitting image light, and a shutter 10 with which the upper part of the film 8 is covered so as to be freely open/shut is provided. Furthermore, the film 8 is laid between a roller 13 provided rotatably on one end side of the aperture part 6 and rotating with the opening/shutting operation of the shutter 10, and a roller 12 provided rotatably on the other end side of the aperture part 6 opposed to the roller 13. The film 8 is taken up by the roller 13 by predetermined length, so as to renew the film 8 with which the aperture part 6 is covered with the opening/shutting operation of the shutter 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projector that projects an image on a screen.

  In recent years, various projectors that display images on a screen have been put into practical use. The projector includes an image generation unit such as a liquid crystal element or a DMD (Digital Micromirror Device). The image generation unit generates image light based on the illumination light emitted from the light source. The image light is enlarged and projected on the screen by the projection optical system.

  A projection optical system is known in which image light is imaged on a screen by a projection lens or a reflecting mirror whose reflective surface is coated with a metal film (see, for example, Patent Document 1). Since the projection lens and the reflecting mirror are often provided so as to be exposed from the main body of the apparatus and dust is easily attached, it is necessary to perform a cleaning operation such as wiping off dust with a special cloth or the like.

  However, there are cases where the reflecting surfaces such as the projection lens and the reflecting mirror are damaged during the cleaning operation. If the reflective surface is scratched, it may affect the image projected on the screen, and it will be necessary to replace the projection lens and reflector. In particular, the reflecting surface of the reflecting mirror is often coated with a metal film, and such a reflecting surface is easily scratched.

  As shown in FIG. 3, in a projector 97 provided with a reflecting mirror 95 that irradiates image light 92 onto a screen 93, a lid 98 integrated with the reflecting mirror 95 is opened during use, and a lid is used when not in use. Some close the section 98. In this way, there is one that prevents dust from adhering to the reflecting surface 95a of the reflecting mirror 95 when the projector 97 is not used.

  However, when the lid 98 of the projector 97 is opened and closed, the hand may touch the reflecting surface 95a of the reflecting mirror 95 provided integrally with the lid 98, and the reflecting surface 95a may be soiled or damaged. Further, when the projector 97 is used, dust adheres to the reflecting surface 95a. For this reason, it is necessary to perform a cleaning operation, and the reflective surface 95a may be damaged.

  In addition, by incorporating a reflecting mirror that irradiates the screen with image light into the housing, forming an opening in the housing through which the image light irradiated on the screen passes, and closing the opening with transparent glass or resin, There is a projector that prevents dust from getting on the reflecting mirror (see, for example, Patent Document 2).

JP 2002-055306 A JP 2004-012749 A

  However, in the projector described in Patent Document 2, since the transparent glass or resin that covers the opening is always exposed, it is necessary to perform a cleaning operation such as wiping off dust attached to the transparent glass or resin at the start of use. is there. In addition, transparent glass or resin may be damaged during storage or cleaning operations. In such a case, it is necessary to exchange transparent glass or resin in order to affect the image projected on the screen.

  It is an object of the present invention to provide a projector that prevents dust and scratches from being attached to a reflecting mirror, and further reduces the number of replacements of a transparent member that closes an opening.

  In the projector according to the present invention, an opening through which image light projected on a screen from a reflecting mirror incorporated in the housing passes is formed in the upper portion of the housing, and in the vicinity of the opening so as to close the opening, A transparent member that transmits image light and a shutter that covers the transparent member so as to be openable and closable are provided.

  The transparent member is rotatably provided at one end of the opening, and is rotatably provided at the other end of the first roller that rotates in accordance with the opening / closing operation of the shutter and the opening opposite to the first roller. A flexible long film stretched between the second roller and the second roller wound up by a predetermined length by the first roller in accordance with the opening / closing operation of the shutter, and a portion for closing the opening is newly renewed. It is characterized by being.

  In the projector according to the present invention, by providing a transparent member that closes the opening formed in the upper part of the housing and a shutter that covers the transparent member, not only the reflection mirror is prevented from getting dust and scratches, but also the transparent member. It is possible to prevent dust and scratches from being attached to the surface, and it is possible to reduce the number of times the transparent member is replaced. In addition, a new part of the transparent member appears in the part that closes the opening in conjunction with the opening of the shutter, so if the shutter is opened and closed even if the transparent member has dust or scratches, the transparent member that closes the opening is clean Thus, there is no need for cleaning work or replacement of the transparent member.

  In FIG. 1 showing the embodiment of the present invention, a housing 5 of the projector 2 has a box shape, and an upper portion thereof has an arc shape. The rectangular opening 6 formed in the upper portion is closed by a part of a long film 8 having flexibility, which is a transparent member that transmits image light. Further, an armor-type shutter 10 that covers the upper side of the film 8 so as to be freely opened and closed is provided.

  When the knob 10a formed on the shutter 10 is slid in the direction of the arrow in the figure, the shutter 10 is retracted to the shutter housing part 5a (see FIG. 2) formed on the housing 5 to open the opening 6, and the direction opposite to the arrow in the figure. When the slider 10 is slid, the shutter 10 is pulled out from the shutter housing 5a, and the opening 6 is closed.

  In FIG. 2 showing the internal structure of the projector 2, the projector 2 includes a film 8, a film feed mechanism that feeds the film 8, a light source 20, an illumination optical system, a total reflection prism 30, a DMD 40, a projection optical system, and a blower mechanism 60. These are provided in a housing 5. In addition, an intake port 62 and an exhaust port (not shown) constituting the air blowing mechanism 60 are provided outside the housing 5.

  The film 8 is supplied by being wound around a roller 12 in a roll shape, and is attached to the back of one end side of the opening 6. The end of the film 8 is joined to a roller 13 provided at a position facing the roller 12 with the opening 6 in between. When the roller 13 is rotated clockwise by the film feeding mechanism, a dirty or damaged part of the film 8 is wound around the roller 13, and a new part of the film 8 is pulled out from the roller 12 to the opening 6. Set. The inner surface of the film 8 is subjected to an inner surface antireflection process for preventing reflection of light in the housing 5.

  The film feeding mechanism includes a shutter 10, rollers 12 and 13, a belt 15, a gear 16, and a one-way clutch 17. When the shutter 10 is slid in the opening direction, the claw 10b formed on the shutter 10 and the gear 16 mesh with each other, the gear 16 rotates, and this rotation is transmitted to the roller 13 by the one-way clutch 17 and rotates clockwise. When the roller 13 rotates, the roller 12 rotates following the belt 15. When the shutter 10 is slid in the closing direction, the claw 10b and the gear 16 mesh with each other, and the gear 16 rotates, but the roller 13 rotates idly by the action of the one-way clutch 17. The belt 15 can be omitted if the roller 12 is rotated without play by following the film 8 transferred along with the rotation of the roller 13 by applying appropriate friction to the roller 12.

  As the light source 20, for example, a white light source such as a xenon lamp or a mercury lamp is used. The illumination light emitted from the light source 20 enters the illumination optical system along the illumination optical axis 22. The illumination optical system includes a color wheel 24, a rod integrator 26, a relay lens 28, and a mirror 29.

  The color wheel 24 separates the illumination light from the light source 20 into three colors of B, G, and R in a time division manner. The color wheel 24 has three color filters from the center of rotation of the substrate: a B filter that transmits only B light, a G filter that transmits only G light, and an R filter that transmits only R light. They are arranged at approximately the same distance. The color wheel 24 rotates at high speed and sequentially inserts the filters of each color into the illumination optical axis 22. As a result, the illumination light is color-separated into three colors B, G, and R in a time-sharing manner, and the light of each separated color is sequentially emitted toward the DMD 40.

  The rod integrator 26 makes the light intensity distribution of the light receiving surface of the DMD 40 uniform from the center to the periphery by making the density of the light beams of the respective colors separated by the color wheel 24 uniform. The rod integrator 26 is formed, for example, by forming a total reflection surface on the inner wall of a glass rod. The light beam that has entered the rod integrator 26 is superimposed by repeating total reflection inside. Thereby, the density of the light beam emitted from the rod integrator 26 is made uniform.

  The relay lens 28 is composed of a convex lens, and relays the light beam emitted from the rod integrator 26 to the mirror 29. The mirror 29 reflects the light beam relayed by the relay lens 28 toward the total reflection prism 30.

  The total reflection prism 30 is for separating incident light incident on the DMD 40 from the mirror 29 and reflected light reflected by the DMD 40. The total reflection prism 30 is composed of, for example, two triangular prisms having different refractive indexes, and a boundary surface 30a is formed at the boundary between the two triangular prisms. Since the incident light has an incident angle larger than the critical angle, the incident light is totally reflected by the boundary surface 30a and enters the DMD 40. On the other hand, the reflected light reflected by the DMD 40 is transmitted through the boundary surface 30a because the incident angle is smaller than the critical angle.

  As is well known, the DMD 40 is a matrix in which a large number of mirror elements each having a light receiving surface corresponding to one pixel are arranged in a matrix. Each mirror element changes the reflection direction of the received illumination light by changing the angle based on the projected image. When displaying pixels brightly, the mirror element is displaced to the on position, and the received light is reflected as on light toward the projection optical system. On the other hand, when the pixel is displayed darkly, the mirror element is displaced to the off position, and the received light is reflected as off light in a direction away from the projection optical system. The image light is constituted by a set of on-lights directed to the projection optical system.

  The projection optical system includes a diaphragm 52 and reflecting mirrors 53, 54, 55, and 56 that reflect light on the reflecting surface. The reflecting surface 53a of the reflecting mirror 53 is configured by a concave curved surface, and the reflecting surfaces 54a, 55a, and 56a of the reflecting mirrors 54, 55, and 56 are respectively configured by convex curved surfaces. The image light generated by the DMD 40 is sequentially reflected by the reflecting surfaces 53 a, 54 a, 55 a, 56 a, passes through the opening 6 and the film 8, and is projected onto the screen 59. The diaphragm 52 cuts extra light such as light other than image light out of the light traveling from the reflective mirror 53a to the reflective mirror 54a.

  Thus, when an image is projected on the screen 59, the light source 20 becomes high temperature. For this reason, the projector 2 is provided with a blowing mechanism 60 that blows cooling air and cools the light source 20. The blower mechanism 60 is provided with a blower chamber 66 in which an intake port 62 for taking in outside air and an exhaust port for exhausting the taken-out outside air are formed.

  The intake port 62 has a filter 68 fitted in an opening 67 formed in the housing 5, and prevents the dust from entering the blower chamber 66 by the filter 68. Similarly, a filter (not shown) is fitted into an opening formed in the housing 5 at an exhaust port (not shown). A blower 70 is provided behind the filter 68. The blower 70 rotates as the connected motor 72 rotates. The blower 70 takes outside air into the blower chamber 66 by rotation, and blows cooling air for cooling the light source 20. The projector 2 rotates the blower 70 when the light source 20 is turned on to suppress the temperature rise of the light source 20 due to image projection.

  The operation of the present invention having the above configuration will be described below. Since the opening 6 formed in the housing 5 of the projector 2 is closed by the film 8, dust does not enter the housing 5. For this reason, dust does not adhere to the reflecting mirrors 53 to 56 incorporated in the housing 5. Further, since it is not necessary to wipe the reflecting mirrors 53 to 56, the reflecting surfaces 53a to 56a of the reflecting mirrors 53 to 56 can be prevented from being damaged. If the opening 6 is closed with the film 8 and the inside of the housing 5 is kept in a secret structure, the reflecting surfaces 53a to 56a do not come into contact with the outside air, and corrosion of the reflecting surfaces 53a to 56a can be prevented.

  When the projector 2 is not used, the film 8 that closes the opening 6 is covered with the shutter 10 so that dust and scratches are not attached. At the start of use of the projector 2, the shutter 10 is slid in the opening direction. At this time, the claw 10 b formed on the shutter 10 meshes with the gear 16 in the projector 2, and the roller 13 rotates through the one-way clutch 17. As a result, the film 8 is wound around the roller 13, the film 8 is conveyed, and a new portion of the film 8 appears at a portion that closes the opening 6. When the shutter 10 is slid in the closing direction, the roller 13 idles and the film 8 is not transferred.

  Thus, since the clean film 8 is always located in the opening 6 when the projector 2 is used, it is not necessary to perform a cleaning operation such as wiping off dust attached to the film 8 at the start of use. When the film 8 becomes dirty or scratched during use, the film 10 that closes the opening 6 can be kept clean by opening and closing the shutter 10, and cleaning work and replacement of the film 8 are performed. Even if not, a good image can be displayed on the screen 59.

  In the above embodiment, the transparent member that closes the opening is renewed in conjunction with the operation of opening the shutter. However, it may be in conjunction with the operation of closing the shutter, and is not necessarily in conjunction with the opening and closing operation of the shutter. May be. For this reason, as long as the transparent member can be exchanged at any time, not only the flexible member such as a film but also a non-flexible member such as a transparent resin or glass may be used. The transparent member is preferably subjected to an internal reflection preventing process.

It is an external appearance perspective view of a projector. It is a schematic block diagram of a projector. It is the external appearance schematic which shows the projector of a prior art example.

Explanation of symbols

2,97 projector 5 housing 6 opening 8 film 10 shutter 10b claw 12, 13 roller 15 belt 16 gear 17 one-way clutch 20 light source 40 DMD
52 Aperture 53, 54, 55, 56 Reflector 53a, 54a, 55a, 56a Reflective surface 59 Screen

Claims (2)

In a projector that projects image light from a reflecting mirror in a housing toward a screen through an opening formed in the upper portion of the housing,
A projector comprising: a transparent member that is provided in the vicinity of the opening so as to close the opening, and that transmits the image light; and a shutter that covers the transparent member in an openable and closable manner.   The transparent member is rotatably provided on one end side of the opening, and is rotatably provided on a first roller that rotates in accordance with the opening / closing operation of the shutter and on the other end side of the opening facing the first roller. A flexible long film stretched between the second roller and wound up by a predetermined length by the first roller in accordance with the opening / closing operation of the shutter, and a portion for closing the opening is renewed. The projector according to claim 1.

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