JP2006098588A - Optical equipment of digital micro mirror system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens protection device capable of easily and surely protecting a projection lens by utilizing the characteristic of a digital micro mirror system in which the projection lens is partially used. <P>SOLUTION: The lens protection device 200 has a 1st protection member 210 covering over the projection non-utilization area 32 of the projection lens; a 2nd protection member 300 attached to relatively rotate to the 1st protection member 210, and covering over the projection utilization area 30 of the projection lens when the optical equipment is not used and exposing the projection utilization area 30 when it is used; and a rotary gear 500 and a motor 600 moving the 2nd protection member 300. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical device using a digital micro mirror, and more particularly to lens protection of a projector that projects an image such as a high definition television (HDTV) or a DVD.

  In projectors and cameras, the projection lens and imaging lens are exposed to the outside, so it is necessary to protect the lens when not in use. For example, Patent Document 1 relates to a lens cap that protects a lens of an imaging apparatus. A cap holding hole is formed in a lens cap holder attached to the grip belt, and an engaging piece of the lens cap is inserted into and engaged with the cap holding hole. Further, the lens cap holder is formed with a cap string through-hole through which the cap string is movably inserted with a certain resistance, and the lens cap can be stored by pulling the end of the cap string. . Thereby, the lens cap can be easily held in the housed state so that the lens cap hangs down in the imaging apparatus and does not interfere with shooting.

  Patent Document 2 relates to a shutter mechanism for protecting a projection lens of a liquid crystal projector device. A shutter for protecting the front surface of the projection lens is provided, and the shutter performs an opening / closing operation in conjunction with a retracting operation of the projection lens, using a zooming motor of the projection lens as a drive source.

JP 2000-194035 A JP 2002-207190 A

  As a technique related to lens protection, there are a technique in which a lens cap and an apparatus main body are connected with a cap string as shown in Patent Document 1, and a technique in which a shutter opening / closing mechanism is provided as shown in Patent Document 2. However, those using a cap string have a problem that they themselves become an obstacle, and those provided with a shutter mechanism have a problem that the design is limited thereby and the cost is increased.

The present invention solves the above-described conventional problems, and can easily and reliably protect the projection lens by utilizing the characteristics of the digital micromirror system that partially uses the projection lens. I will provide a.
It is a further object of the present invention to provide a projector having such an improved lens protection device.

  A digital micromirror type optical apparatus according to the present invention includes a digital micromirror that generates projection light, a projection lens that includes a first region that is not used for projection and a second region that can be used for projection, and a projection lens. A protection device for protecting the first protection member that covers the first region of the projection lens and is movable relative to the first protection member and is not used. A second protective member that sometimes covers the second region of the projection lens and exposes the second region when in use, and a movement control means for moving the second protective member.

  Preferably, the first protection member is fixedly attached to the projection lens, and the second protection member is rotated relative to the first protection member. The first protection member includes a first protection part corresponding to the first region and a first exposed part corresponding to the second region, and the second protection member is a second protection part. And the second exposed portion, the second exposed portion overlaps the first exposed portion when in use, and the second protected portion overlaps the first exposed portion when not in use The member is rotated. More preferably, the second protection member includes a movable member whose position is changed in conjunction with the rotational movement of the second protection member, and the movable member overlaps with the first protection portion when in use, and when not in use. It exists in the position which overlaps with a 1st exposed part. The second protection member includes a fulcrum at a position offset from the rotation center, and the movable member is rotatably supported by the fulcrum. When not in use, the first protection unit, the second protection unit, and the movable member The projection lens is protected by the cover.

  Preferably, the movement control means moves the second protection member to a use position when the power switch of the optical apparatus is turned on, and moves the second protection member to a non-use position when the power switch is turned off. Move to.

  According to the present invention, it is possible to protect the projection lens with a configuration at a low cost without adding restrictions on the main body design of the digital micromirror optical device. Furthermore, loss of the protective device can be prevented.

  The digital micromirror type optical apparatus according to the present invention is implemented in a projector. Hereinafter, it will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an optical system of a projector using a digital micromirror. In the figure, 10 is an arc (light emitting point) of a white light source, 12 is an elliptical mirror as a condensing mirror, and 14 is a rotatable color filter in which an annular portion is divided into three primary colors (red, green, and blue) of light. , 16 is a light tunnel which is an optical component, 18 is a condenser lens, 20 is a plane mirror as a folding mirror, 22 is a spherical mirror as a second folding mirror, 24 is a DMD (digital micromirror device), and 26 is a DMD. A second condenser lens 28, which is disposed on the front surface, is a projection lens.

  In the DMD 24, each pixel arranged two-dimensionally is composed of a minute mirror, and the inclination of the minute mirror is controlled by an electrostatic field effect by a memory element arranged immediately below each pixel, thereby changing the reflection angle of reflected light. Thus, it is a reflective display element that creates an on / off state. When the pixel is off, the reflected light from the pixel's micromirror does not enter the projection lens. When the pixel is on, the reflected light from the pixel's micromirror enters the projection lens and forms an image on the screen. System parts are arranged. The tilt angle of each pixel when the micromirror is on is determined to be about 10 to 12 degrees with respect to the incident surface of the DMD beam.

  The light from the light source 10 is sequentially separated into R, G, and B light by the color filter 14, which illuminates the DMD 24. On-state light reflected by the DMD 24 is magnified by the projection lens 28 and projected on the screen.

  The projection lens 28 receives the light in the ON state from the DMD 24, but there is an area that is not actually used for projection on the projection lens. FIG. 2 is a plan view and a side view schematically showing the projection lens. The projection lens 28 includes an area 30 used for projection (hereinafter referred to as a projection use area) and an area 32 not used for projection (hereinafter referred to as a non-projection use area) 32. This is because the on-state light from the DMD 24 is reflected at a certain angle. In the case of the projector of this embodiment, the projection use area 30 occupies more than half of the upper side of the projection lens 28, and the projection light incident thereon is enlarged and projected. The non-projection utilization area 32 is less than half of the lower side of the projection lens 28 and is smaller than the area of the projection utilization area 30.

  In this embodiment, in view of the fact that the non-projection utilization area 32 exists in a part of the projection lens 28, a lens protection device suitable for this is configured. FIG. 3 is an external perspective view of a projector equipped with the lens protection device of this embodiment.

  In addition to the optical system shown in FIG. 1, the projector 100 includes a housing 110 that houses a power source, a circuit board, and the like. A lens protection device 200 that protects the projection lens is attached to the front surface 112 of the housing 110. Further, a slit 114 for sucking and discharging outside air is formed on the front surface 112, and an operation button 118 is attached to the upper surface 116.

  The lens protection device 200 includes a plurality of protection members, a rotation gear 500 and a motor 600 arranged in the housing 110. Details of the plurality of protection members are shown in FIG. The lens protection device 200 includes a cylindrical first protection member 210, a cylindrical second protection member 300 attached to the first protection member 210, and a movable member 400 attached to the second protection member 300. have.

  The first protective member 210 has an outer peripheral portion 220 having a predetermined inner diameter and a first protective portion 230 formed on the front surface side of the outer peripheral portion 220. As described above, the first protection unit 230 is desirably designed to have a size and shape corresponding to the non-projection use area 32 of the projection lens 28. Here, the first protection unit 230 has a linear boundary 232, covers the non-projection use area 32 of the projection lens 28 below the boundary 232, and covers the first exposed part 240 above the boundary 232. The projection use area 30 of the projection lens 28 is always exposed by the first exposure portion 240.

  The back surface side of the first protection member 210 is open, and the projection lens holding member 250 is inserted from this open surface (see FIG. 4C). The projection lens holding member 250 has a cylindrical outer peripheral portion 252 having an outer diameter substantially equal to or slightly smaller than the inner diameter of the outer peripheral portion 220 of the first protective member 210. Thereby, the first protection member 210 is fixedly fitted to the projection lens holding member 250. In addition, the projection lens 28 is held inside the outer peripheral portion 252, and both are positioned so that the non-projection use area 32 of the projection lens 28 coincides with the first protection unit 230. Preferably, in order to facilitate positioning, an engaging portion such as a recess or a protrusion that engages with each other may be provided.

  The second protective member 300 has a cylindrical outer peripheral portion 310 that covers the outer peripheral portion 220 of the first protective member 210. A groove 312 is formed on the inner side of the outer peripheral portion 310 in the circumferential direction. The groove 312 engages with a protruding portion 222 formed along the outer periphery of the outer peripheral portion 220 of the first protective member 210, whereby the second protective member 300 slides on the first protective member 210. It can be rotated while.

  On the front side of the second protective member 300, a second protective part 320 and a rectangular second exposed part 330 are formed. When the rotation center of the second protective member 300 is C, the second exposed portion 330 has a size including the center C, in other words, a size corresponding to the projection use area 30 of the projection lens 28. ing. A part of the outer peripheral part 310 of the second protective member 300 is cut off, and the second exposed part 330 is cut off and connected to the part.

  A protrusion 322 is provided on the back surface of the second protection part 320 at a position offset from the center C. The protrusion 322 supports the movable member 400 described later. Furthermore, an uneven gear portion 340 is formed along the circumferential direction of the outer peripheral portion 310 of the second protective member 300. As shown in FIG. 3, the gear portion 340 meshes with the rotation gear 500 rotated by the motor 600, thereby rotating the second protection member 300 relative to the first protection member 210.

  The movable member 400 includes a third protection part 410 made of a fan-shaped thin plate member, and a slit-like support hole 420 formed on the third protection part 410. The horizontal length of the third protection part 410 is somewhat longer than the horizontal length of the second exposed part 330 of the second protection member 300. Further, the bottom portion of the third protection portion 410 has a curvature that is substantially equal to the outer peripheral portion 310 of the second protection member 300. The protrusion 322 of the second protection member 300 is inserted into the support hole 420 of the movable member 400, whereby the movable member 400 is attached to the back surface side of the second protection member 300.

  When the second protection member 300 rotates, the position of the protrusion 322 offset from the center C changes, and the position of the movable member 400 changes in conjunction with this. When the second exposed portion 330 of the second protection member 300 is located at the uppermost position, the movable member 400 is located at the lowermost position, and the bottom thereof is in contact with or close to the second protection member 300. Further, when the second exposed portion 330 is located at the lowermost position, the protrusion 322 is located at the uppermost position, that is, the movable member 400 is located at the uppermost position. When the movable member 400 is located at the uppermost position, as shown in FIGS. 4B and 4C, the third protective part 410 of the movable member is formed by the first protective part 230 and the second protective part 330. The gap S is blocked.

  FIG. 5 is a block diagram showing an electrical configuration of the projector. The control unit 700 is constituted by a microcomputer, for example, and executes a desired operation sequence by a program stored in a memory. The input unit 710 is a user interface that receives instructions from the user. The user gives an instruction to adjust the brightness of the projected image and an instruction to turn on / off the lamp to the control unit 700 from the operation button 118 or the remote controller. The power switch 720 gives a signal in response to power on / off to the control unit 700. When the power-on signal is input, the control unit 700 performs sequence control for starting the operation of the DMD driving circuit 730, the lamp lighting circuit 740, and the motor driving circuit 750.

  Next, the lens protection operation of the projector will be described. FIG. 6 is a diagram illustrating a positional relationship among the first protection member 210, the second protection member 300, and the movable member 400 when the lens protection device is viewed from the front. Here, in order to easily understand the protection state of the projection lens, the anteroposterior relationship of each member is ignored. The first protective member 210 indicates the position in the diagonal direction, the second protective member 300 indicates the position without hatching, and the movable member 400 indicates the position in the vertical direction.

  FIG. 5A shows a state where the lens protection device is closed, that is, a state where the power switch is turned off. At this time, the non-projection use area 32 of the projection lens 28 is covered by the first protection part 230 of the first protection member 210, and the projection use area 30 of the projection lens 28 is exposed by the first exposure part 240. . That is, the upper half or more of the projection lens 20 is exposed. On the other hand, the second protection member 300 is in an initial state, and the second protection part 320 is located at the uppermost position (the second exposed part 330 is located at the lowermost position). Since the second exposed portion 330 is approximately the same size as the projection use area 30, the area of the lower half or more of the projection lens 28 is exposed. That is, a part of the first exposed portion 240 and the second exposed portion 330 overlap each other, in other words, a gap S is generated between the first protective portion 230 and the second protective portion 320, The entire surface of the projection lens 28 cannot be covered. This overlapping portion (gap S) is covered by the third protection part 410 of the movable member 400 lifted upward by the second protection member 300. Thus, the projection lens 28 is completely covered and protected by the first protection unit 230, the second protection unit 320, and the third protection unit 410.

  Next, when the power switch of the projector is turned on, a signal indicating the on state is supplied from the power switch 720 to the control unit 700. The controller 700 rotates the motor 600 via the motor drive circuit 750 in response to this signal. Accordingly, the second protection member 300 is rotated via the gear portion 340 that engages with the rotation gear 500.

  FIG. 5B shows a state where the second protective member 300 is rotated 45 degrees clockwise. FIG. 5C shows a state in which the second protective member 300 is rotated 90 degrees clockwise. The second exposed portion 330 gradually appears. FIG. 5D shows a state where the second protective member 300 is rotated 180 degrees, that is, a state where the protective device is completely opened. The controller 700 rotates the second protective member 300 to this position.

  When in the state shown in FIG. 5D, the second exposed portion 330 of the second protective member 300 is located at the uppermost position, and the second exposed portion 330 and the first exposed portion 240 coincide. That is, the projection utilization area 30 of the projection lens 28 is completely exposed. When the second exposed portion 340 is located at the uppermost position, the projecting portion 322 is located at the lowermost position. Therefore, the movable member 400 is located below the center C by an offset amount, and the lower portion is located on the second protective member 300. Abut or close. At this time, the movable member 400 is within a range that does not exceed the first protection portion 230 of the first protection member. Thus, the projection lens 28 is exposed, and light from the DMD 24 is projected on the screen via the projection lens 28.

  When the power switch is turned off, the control unit 700 rotates the second protective member 300 clockwise by 180 degrees or counterclockwise to close the lens protective device as shown in FIG. .

  In order to accurately control the rotation angle of the second protective member 300, it is desirable to use a stepping motor. Further, a position sensor may be provided to determine whether or not the second protective member 300 is in the initial position.

  As described above, according to this embodiment, the projection lens can be protected or exposed only by attaching the first and second protection members to the projection lens holding member 250 and rotating the second protection member by the motor. Can be done easily. For this reason, an inexpensive lens protection device can be provided without using a complicated mechanism or device.

  In the above embodiment, the lens protection device is opened / closed in response to turning on / off of the power switch. However, the present invention is not limited to this. For example, the user may give an instruction to open / close the lens protection device. Or you may make it respond to on / off of a lamp lighting device. Further, the shape and size of the exposed portion of the first and second protection members and the shape and size of the movable member can be appropriately changed according to the size of the projection lens, the size of the projection use area 30, and the like. It is.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Modifications and changes are possible.

  The digital micromirror type optical apparatus according to the present invention can be used in a front projection type projector or a rear projection type projector. Further, in addition to the projector, it can also be used as a protection device for an optical unit of a digital camera using DMD.

It is a figure which shows the optical system of the projector using DMD which concerns on the Example of this invention. It is a figure which shows the area | region utilized for projection of a projection lens, and the area | region not utilized for projection. 1 is an external perspective view of a projector equipped with a lens protection device of an embodiment. 4A is a diagram illustrating the configuration of each part of the lens protection device, FIG. 4B is a diagram of the lens protection device viewed from the front, and FIG. 4C is a diagram illustrating a cross-sectional structure of the lens protection device. is there. It is a block diagram which shows the electric structure of a projector. 6A and 6B are diagrams for explaining the operation of the lens protection device, FIG. 6A shows a state where the lens protection device is closed, FIG. 6B shows a state where the second lens protection member is rotated 45 degrees, 6 (c) shows a state where the second lens protection member is rotated 90 degrees, and FIG. 6 (d) shows a state where the second lens protection member is rotated 180 degrees (a state where the lens protection device is opened).

Explanation of symbols

24: DMD 28: Projection lens 30: Projection use area 32: Non-projection use area 100: Projector 110: Housing 200: Lens protection device 210: First protection member 220: Outer peripheral part 222: Projection part 230: First protection Part 232: Boundary 240: First exposed part 250: Projection lens holding member 300: Second protective member 310: Outer peripheral part 312: Groove 320: Second protective part 322: Projection part 330: Second exposed part 340 : Gear part 400: movable member 410: third protection part 420: support hole S: gap

Claims (6)

A digital micromirror that generates projection light;
A projection lens having a first region not used for projection and a second region available for projection;
A protective device for protecting the projection lens,
The protection device includes a first protection member that covers a first region of the projection lens;
A second protective member that is movable relative to the first protective member, covers the second region of the projection lens when not in use, and exposes the second region when in use;
Movement control means for moving the second protective member;
A digital micromirror optical device. 2. The digital micromirror type of claim 1, wherein the first protection member is fixedly attached to the projection lens, and the second protection member is rotated relative to the first protection member. Optical equipment. The first protection member includes a first protection part corresponding to the first region and a first exposed part corresponding to the second region, and the second protection member includes the second protection part and the second protection part. Two exposed parts,
The second protective member is rotated so that the second exposed portion overlaps the first exposed portion when in use and the second protected portion overlaps the first exposed portion when not in use. 2. A digital micromirror optical device according to 2. The second protection member includes a movable member whose position is changed in conjunction with the rotational movement of the second protection member. The movable member overlaps with the first protection portion when used, and the first exposed portion when not used. The digital micromirror type optical device according to claim 3, wherein the optical device is in a position overlapping with the optical micromirror device. The second protection member includes a fulcrum at a position offset from the rotation center, and the movable member is rotatably supported by the fulcrum. When not in use, the first protection unit, the second protection unit, and the movable member 5. The optical device of the digital micromirror type according to claim 4, wherein the projection lens is protected by the optical device. The movement control means moves the second protective member to a position when in use when the power switch of the optical device is turned on, and moves the second protective member to a position when not in use when the power switch is turned off. The digital micromirror type optical device according to any one of claims 1 to 5, wherein the optical device is moved.

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