JP2006201646A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector designed such that the operation of opening/closing a lens cap (lens protective member) also functions as a switch for turning on/off the projector. <P>SOLUTION: The projector 100 includes: the lens protective member 120 capable of protecting a projection lens 28 mounted on the front of a housing; and the main switch 130 for turning on/off the projector in accordance with the position of the lens protective member 120. The lens protective member 120 is slidable. When the lens protective member 120 is in an opened position, the main switch 130 is turned on. When the lens protective member 120 is in a closed position, the main switch 130 is turned off. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a front-projection or rear-projection projector that can project an image such as a television or a DVD, and more particularly to protection of a projector projection lens.

  A projector that displays a color image using liquid crystal or DMD (Digital Micro-mirror Device) as a spatial modulation element has been put into practical use. The projector includes a projection lens for enlarging and displaying the light modulated by the spatial modulation element on the screen. The projection lens is exposed from the projector housing, and when not in use, the projection lens is protected by a lens cap or the like. On the other hand, if light is projected from the projection lens with the lens cap attached, the lens cap will be deformed by heat, and the optical and electronic devices inside the projector will be adversely affected by the heat. When using the projector, the lens cap must be removed from the projection lens.

  In addition to protecting the projection lens, Japanese Patent Laid-Open No. 2004-151620 discriminates the presence or absence of projection light by blocking the projection light from the projection lens while causing leakage light to the operator or the explainer on the projection side. Provides a projection lens cap that can Specifically, the outer peripheral surface of the lens cap is made a translucent surface, or a hole is formed in the outer peripheral surface.

  Patent Document 2 relates to a technique for preventing forgetting to remove a lens cap of a projector. The lens cap includes a cap body and optical means. The cap body is made of polycarbonate, and a light transmitting part is formed at the center thereof. Optical means is mounted on the translucent part, and the optical means includes lens means and display means. When the projector is operated with the lens cap attached, characters on the display means are enlarged and projected onto the screen. And forgetting to remove the lens cap.

  Patent Document 3 detects the attachment / detachment of the lens cap, and prevents the lens cap from being deformed by preventing the lamp power source for the light source lamp from being turned on when the lens cap is attached. In this projector, a lens cap detector that detects attachment of a lens cap that protects the projection lens is provided in the vicinity of the projection lens, and a lamp control unit that inputs and outputs a detection signal from the lens cap detector and turns the lamp power on and off. When the lens cap is mounted, the lamp power supply is controlled to be cut off. This prevents the lens cap from being melted and deformed even when the power is turned on with the lens cap attached by mistake.

  Patent Document 4 provides a projector that can reliably prevent deformation of the lens cap without disconnecting the lamp power supply when the lens cap is attached to the projection lens while the lamp is on. This projector blocks the light from the lamp 13 when it is determined that the lens cap is attached based on a signal from the detection unit and a signal from the detection unit. Alternatively, a projection display control unit that controls the liquid crystal panel so as to reduce the light is provided.

  In Patent Document 5, when the light path for projecting an image is blocked by a cap, the power supplied to the lamp is reduced to reduce the heat generation in the lamp power supply without causing any trouble in use. It is an object of the present invention to provide a projector that can be made to operate.

JP2003-20098A JP 2003-149742 A JP 2002-122940 A JP 2004-245986 A JP-A-10-239767

  The above-described conventional example discloses a technique for detecting the presence or absence of a lens cap and the like and turning off the lamp or reducing the power when the lens cap is attached. In such a projector, the opening / closing operation of the lens cap and the on / off operation of the main switch of the projector are performed separately. Therefore, if the user does not notice the mounting of the lens cap, the main switch is turned on. Despite this, it may be confusing why the light source does not turn on. Furthermore, Patent Documents 3 and 4 require a separate detector for detecting the lens cap, which increases the cost of the apparatus.

  The present invention has been made to solve the above-described problems, and provides a projector in which a switching function for turning on / off the projector is also used for opening / closing operations of a lens protection member (lens cap, etc.) of the projector. Objective.

A projector according to the present invention includes a light source, a modulation unit that modulates light from the light source,
A projection lens that projects the modulated light, a lens protection member that can protect the projection lens, and a switch unit that switches between an on state and an off state in response to the position of the lens protection member.

  Preferably, the projection lens is protected by the lens protection member when the lens protection member is in the first position, and the projection exposed from the lens protection member when the lens protection member is in the second position. The lens is in a state where it can project light, and the switch means switches to the on state in response to the lens protection member being in the second position.

  The lens protection member may be rotatably attached to the projection lens and may be moved to the first position or the second position by a rotation operation, or may be slidably attached to the projection lens and may be moved by the slide operation. It may be moved to the first position or the second position.

  Preferably, the switch means is a main switch of the projector, and the lens protection member is a lens cap. By manually moving the lens protection member to the first or second position, the main switch is turned on / off. Turning off the main switch includes, for example, a state in which the operation of an internal circuit (such as a lamp lighting circuit) of the projector is substantially stopped and a state in which power supply to the internal circuit is stopped.

  According to the projector of the present invention, since the switch means for switching the on state or the off state in response to the position of the lens protection member is provided, the on state or the off state is switched in conjunction with the use state of the lens protection member. It can be performed. Accordingly, it is reliably prevented that the lens protection member is forgotten and light is projected from the projection lens. In addition, by linking the lens protection member and the switch means, it is possible to provide a user-friendly projector without increasing the number of parts.

  The projector according to the present invention is preferably used in a DLP 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 DMD. 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 the primary color of light in the zone part (red, green, blue, or red, green, blue, white). A color wheel device including a rotatable filter divided into two parts, 16 a light tunnel which is an optical component, 18 a condenser lens, 20 a plane mirror as a folding mirror, 22 a spherical mirror as a second folding mirror, 24 Is a DMD, 26 is a second condenser lens disposed in front of the DMD, and 28 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 to change 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.

  FIG. 2 is a front view of the projector. In addition to the optical system shown in FIG. 1, the projector 100 has a housing that houses a power supply, a circuit board, and the like. A suction / exhaust slit 112 is formed on the front surface 110 of the housing, and a lens protection member 120 for protecting the projection lens 28 exposed from the housing is attached. The lens protection member 120 is a plate-like member, and can slide the front side 110 in the horizontal direction. As shown in FIG. 2A, when the lens protection member 120 is located on the leftmost side (open position), the projection lens 28 is exposed, and light can be projected from the projection lens 28. When the lens protection member 120 is slid and positioned on the rightmost side (closed position) as shown in FIG. 2B, the projection lens 28 is covered and the lens surface is protected.

  A main switch 130 that turns on and off according to the position of the lens protection member 120 is attached in the housing. The main switch 130 is engaged with the lens protection member 120, and a mechanical switch that operates in response to the movement of the lens protection member 120 can be used. When the lens protection member 120 is in the open position in FIG. 2A, the main switch 130 is turned on, and when the lens protection member 120 is in the closed position in FIG. 2B, the main switch 130 is turned off.

  FIG. 3 is a block diagram showing an electrical configuration of the projector. The control unit 700 is configured by a microcomputer, for example, and executes a desired operation sequence by a program stored in a memory such as a RAM or a ROM. A main switch 130 is connected to the control unit 700, and when the main switch 130 is turned on, the control unit 700 becomes operable. The controller 700 is connected to the DMD driving circuit 720, the lamp driving circuit 730, and the color wheel driving circuit 740 via the bus 710, and supplies signals for controlling these. Further, the control unit 700 supplies enable signals EN1, EN2, and EN3 for enabling the DMD driving circuit 720, the lamp driving circuit 730, and the color wheel driving circuit 740.

  The DMD driving circuit 720 drives the DMD 24 in accordance with the DMD format image data generated by the control unit 700. The lamp driving circuit 730 performs power control when the lamp 10 is ignited, turned off, and turned on. The color wheel drive circuit 740 controls the drive of the motor of the color wheel device 14. The power supply circuit 750 supplies predetermined power to the control unit 700, the DMD drive circuit 720, the lamp drive circuit 730, and the color wheel drive circuit 740 via lines L1, L2, L3, and L4.

  When the lens protection member 120 is closed (the state shown in FIG. 2B), the main switch 130 is off, that is, the circuit of the control unit 700 is open. In this state, the enable signals EN1, EN2, and EN3 from the control unit 700 are at a low level (ground level), and the DMD driving circuit 720, the lamp driving circuit 730, and the color wheel driving circuit 740 are not substantially driven. Accordingly, the projector is turned off, and the light from the projection lens 28 is not projected onto the lens protection member 120.

  On the other hand, when the user manually slides the lens protection member 120 to the opened state (the state shown in FIG. 2A), the main switch 130 is turned on in response to this, and the circuit of the control unit 700 is closed. As a result, the enable signals EN1, EN2, and EN3 from the control unit 700 become high level (for example, 5 volts), the DMD driving circuit 720, the lamp driving circuit 730, and the color wheel driving circuit 740 can be driven. Operated according to the sequence. When the modulated light is projected from the projection lens 28, the lens protection member 120 is in the open position, and the lens protection member 120 is not irradiated with the light.

  As described above, according to the present embodiment, since the lens protection member 120 is provided with the on / off function of the main switch 130, the main switch is not turned on unless the lens protection member 120 is opened. The lens protection member is not irradiated with light due to forgetting to remove it. In other words, no light is irradiated from the projection lens unless the lens protection device 120 is opened. Accordingly, the user can simultaneously perform the opening / closing operation of the lens protection member and the on / off operation of the projector, and the operation efficiency can be improved.

  In the above embodiment, the lens protection member is slid, but the lens protection member may be rotated. For example, the lens protection member may be a cylindrical lens cap that covers the projection lens 28, and the projection lens may be exposed or covered by rotating the lens cap. For example, as shown in FIG. 4, a lens cap 140 for protecting the projection lens 28 can be attached to the front surface 110 of the projector 100. The lens cap 140 can be manually rotated, and the main switch 130 is turned on when the lens cap 140 is in the open position, and the main switch 130 is turned off when the lens cap 140 is in the closed position.

  FIG. 5 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. 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 or equal to the lower half of the projection lens 28 and is smaller than the area of the projection utilization area 30.

  The configuration of the lens cap using the non-projection utilization area is shown in FIG. The lens cap 200 includes a cylindrical first protective member 210, a cylindrical second protective member 300 attached to the first protective member 210, and a movable member 400 attached to the second protective 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. The first protection unit 230 is designed to have a size and shape corresponding to the non-projection use area 32 of the projection lens 28 as described above. 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. 6C). 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 connected to the cut off 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.

  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. 6B and 6C, 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. 7 shows the positional relationship between the first protection member 210, the second protection member 300, and the movable member 400 when the lens cap 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. 7A shows a position where the lens cap is closed, that is, a state where the main switch 130 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. . 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.

  FIG. 7B shows a state where the second protective member 300 is rotated 45 degrees clockwise. FIG. 7C shows a state in which the second protective member 300 is rotated 90 degrees clockwise. The second exposed portion 330 gradually appears. FIG. 7D shows a state where the second protective member 300 is rotated by 180 degrees, that is, 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 second exposed portion 330 And the exposed portion 240 of the projection lens 28 are 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 main switch 130 is turned on, and the control unit 700 sets the enable signals EN1, EN2, and EN3 to high level to operate each unit. Thus, the light from the DMD 24 is projected on the screen from the exposed projection lens 28.

  Next, another mode in which the projector is turned off using the main switch will be described. As shown in FIG. 8A, the main switch 130 is connected between the power supply circuit 750 and the internal circuit 800, and when the main switch 130 is turned on, the power from the power supply circuit 750 is supplied to the internal circuit 800. You may do it. When the main switch 130 is off, power is not supplied to the internal circuit 800 and the operation of the internal circuit 800 is not performed. The internal circuit 800 includes a control unit 800, a DMD driving circuit 720, a lamp driving circuit 730, and a color wheel driving circuit 740 shown in FIG.

  Further, as shown in FIG. 8B, the main switch 130 may be connected to the power supply circuit 750, and the power supply circuit 750 may be operated when the main switch 130 is turned on. While the main switch 130 is off, power is not supplied to the internal circuit 800. Further, as shown in FIG. 8C, the main switch 130 may be connected to the internal circuit 800, and the internal circuit 800 may operate when the main switch 130 is turned on. In this case, of the internal circuit 800, for example, only the lamp driving circuit 730 may be selectively on / off controlled.

  Although the preferred embodiment of the present invention has been described in detail, the present invention is not limited to the specific embodiment, and various modifications, within the scope of the gist of the present invention described in the claims, It can be changed.

  The lens protection member or the lens cap according to the present invention can be used in an image display apparatus such as a projector using DMD, liquid crystal, or other modulation elements.

It is a figure which shows the optical system of the projector which concerns on the Example of this invention. FIG. 2A is a front view of the projector according to the present embodiment, FIG. 2A shows a state where the lens protection member is opened, and FIG. 2B shows a state where the lens protection member is closed. It is a block diagram which shows the electric constitution of the projector of a present Example. It is a perspective view which shows the external appearance of the projector of another Example. It is a figure explaining a projection lens. It is a figure which shows the structure of the lens cap of another Example. It is a figure explaining operation | movement of a lens cap. It is a figure which shows the example of other on / off using the main switch.

Explanation of symbols

10: Lamp 24: DMD
28: Projection lens 100: Projector 110: Front 120: Lens protection member 130: Main switch 200: Lens cap

Claims (8)

A light source;
Modulation means for modulating light from the light source;
A projection lens that projects the modulated light;
A lens protection member capable of protecting the projection lens;
Switch means for switching between an on state and an off state in response to the position of the lens protection member;
Projector. When the lens protection member is in the first position, the projection lens is protected by the lens protection member. When the lens protection member is in the second position, the projection lens exposed from the lens protection member is light. The projector according to claim 1, wherein the switch means switches to an on state in response to the protection member being in the second position. The projector according to claim 2, wherein the lens protection member is rotatably attached to the projection lens and is moved to the first position or the second position by a rotation operation. The projector according to claim 2, wherein the lens protection member is slidably attached to the projection lens and is moved to the first position or the second position by a sliding operation. The projector according to claim 1, wherein the off state includes a state in which an operation of an internal circuit of the projector is substantially stopped. The projector according to claim 1, wherein the off state includes a state in which power supply to an internal circuit of the projector is stopped. The projector according to claim 1, wherein the switch means is a main switch of the projector. The projector according to claim 1, wherein the projector holds the light source, the modulation unit, and the projection lens in the housing, and protects the projection lens exposed from the front surface of the housing with a lens protection member.

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