Source: http://www.google.com/patents/US8152313?dq=6,952,563
Timestamp: 2017-05-26 12:47:37
Document Index: 393752406

Matched Legal Cases: ['art.\n4', 'Application No. 2008', 'art 681', 'art 681', 'art 682', 'art 682', 'art 682', 'art 681', 'art 682', 'art 682', 'art 682', 'art 682', 'art 682', 'art 682', 'art 681', 'art 682', 'art 682', 'art 682', 'art 682', 'art 682']

Patent US8152313 - Projection display device that displaces an optical position of an imager in ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inPatentsA projection display device has an imager that modulates light from a light source in accordance with an image signal, a projection optical system that enlarges and projects the light modulated by the imager onto a projection plane, a focus adjustment part disposed in the projection optical system, and...http://www.google.com/patents/US8152313?utm_source=gb-gplus-sharePatent US8152313 - Projection display device that displaces an optical position of an imager in conjunction with a focus adjustmentAdvanced Patent SearchTry the new Google Patents, with machine-classified Google Scholar results, and Japanese and South Korean patents.Publication numberUS8152313 B2Publication typeGrantApplication numberUS 12/426,725Publication dateApr 10, 2012Filing dateApr 20, 2009Priority dateMay 9, 2008Fee statusLapsedAlso published asUS20090279055Publication number12426725, 426725, US 8152313 B2, US 8152313B2, US-B2-8152313, US8152313 B2, US8152313B2InventorsRyuhei AmanoOriginal AssigneeSanyo Electric Co., Ltd.Export CitationBiBTeX, EndNote, RefManPatent Citations (5), Referenced by (2), Classifications (6), Legal Events (4) External Links: USPTO, USPTO Assignment, EspacenetProjection display device that displaces an optical position of an imager in conjunction with a focus adjustment
US 8152313 B2Abstract
an imager that modulates light from a light source in accordance with an image signal;
a projection optical system that enlarges and projects the light modulated by the imager onto a projection plane;
a focus adjustment part provided in the projection optical system;
a displacement part that displaces an optical position of the imager relative to the projection optical system in a direction vertical to a light axis of the projection optical system in conjunction with the focus adjustment part; and
a drive part that drives the focus adjustment part and the displacement part in accordance with a throw distance from the projection optical system to the projection plane, wherein
the drive part drives the focus adjustment part and the displacement part in such a manner that an amount of shift of the imager from the light axis becomes smaller with the increasing throw distance.
3. The projection display device according to claim 1, further comprising:
a distance detection part that detects a distance in relation to the throw distance, wherein
the drive part includes a drive source for driving the focus adjustment part and the displacement part, and controls the drive source in accordance with the distance detected by the distance detection part.
4. The projection display device according to claim 3, further comprising:
a slide stage on which a main body of the projection display device is placed in such a manner that the main body can slide in directions that come closer to or away from the projection plane, wherein
the distance detection part includes a detection part for detecting a movement distance of the main body on the slide stage from a reference position, as the distance in relation to the throw distance.
5. The projection display device according to claim 3, wherein
the distance detection part includes a distance sensor that detects a distance from a predetermined reference surface as the distance in relation to the throw distance, and
the focus adjustment part makes a focus adjustment when the projection display device is in a first position, and thereafter, when the projection display device is moved to a second position different from the first position, the drive part acquires an amount of control on the drive source after the movement, on the basis of the two distances detected by the distance sensor before and after the movement, respectively. Description
This application claims priority under 35 U.S.C. Section 119 of Japanese Patent Application No. 2008-123922 filed May 9, 2008, entitled “PROJECTION DISPLAY DEVICE”.
At present, there are commercialized and widely spread projection display devices (hereinafter, referred to as “projectors”) that enlarge and project an image on an imager (such as a liquid crystal panel) onto a projection plane (such as a screen). For this kind of projectors, various techniques for shortening a throw distance have been proposed. The term “throw distance” herein refers to a distance from a projection aperture in a projector or a terminal optical component in a projection optical system to a plane including a projection plane. If the throw distance is short, projected light is less prone to be cut off by some obstacle, thereby increasing usability of the projector and convenience of a user.
On a projector with such an oblique-projection arrangement, a size of a projected image (hereinafter, referred to as “projection size”) can be adjusted by changing the throw distance as appropriate. For example, the projection size can be decreased by making the projector closer to the screen to shorten the throw distance. In addition, the projection size can be increased by making the projector away from the screen to lengthen the throw distance.
The housing 100 stores the optical engine 200, and the optical engine 200 generates light modulated in accordance with an image signal (hereinafter, referred to as “image light”). The lens unit 300 is attached to the optical engine 200, and the image light emitted from the optical engine 200 is entered into the lens unit 300. In the optical engine 200, an imager 200 a generating the image light is disposed in such a manner that a center of an effective display area thereof is shifted by a predetermined distance d from a light axis L1 of the lens unit 300.
The lens unit 300 has a focus adjustment lever 301 (hereinafter, referred to as “focus lever”). As described later, a user can operate the focus lever 301 to make a focus adjustment and a position adjustment to an image projected onto a screen.
In the projector, when a distance between the screen and the projector main body is changed, a throw distance H of image light (refer to FIG. 3) from the projector to the screen is changed accordingly, whereby a projection size is enlarged or contracted. Accordingly, the projection size can be decreased by making the projector main body closer to the screen, and the projection size can be increased by making the projector main body away from the screen. In this embodiment, a distance from the terminal optical component (the reflective mirror 400) in the projection optical system to the projection plane is designated as “throw distance”.
FIG. 2A is a top perspective view of an internal structure of the optical engine 200. As shown in FIG. 2A, the optical engine 200 includes a light source 201, a light-guiding optical system 202, three transmissive liquid crystal panels 203, 204, and 205 as an imager 200 a, and a dichroic prism 206. The liquid crystal panels 203, 204, and 205 each have polarizers (not shown) on an incident side and an output side. The liquid crystal panels 203, 204, and 205 and the dichroic prism 206 are formed as an imager module 207. These optical components are disposed on an installation plate 208.
A white light emitted from the light source 201 is separated by the light-guiding optical system 202 into a red-waveband light (hereinafter, referred to as “R light”), a green-waveband light (hereinafter, referred to as “G light”), and a blue-waveband light (hereinafter, referred to as “B light”), and then applied to the liquid crystal panels 203, 204, and 205. The R, G, and B lights modulated by the liquid crystal panels 203, 204, and 205 are combined and emitted as image light by the dichroic prism 206.
An inner cylinder 303 is disposed in an outer cylinder 302 of the lens unit 300. A base end of the focus lever 301 is fixed to the inner cylinder 303. The focus lever 301 is rotatable by a predetermined range in an in-plane direction of a Y-Z plane in the diagram. The outer cylinder 302 has a slit 302 a spanning the rotatable range of the focus lever 301. The focus lever 301 is exposed through the slit 302 a to outside the outer cylinder 302.
For example, if the projector is located at the shortest throw distance H with which the projection size becomes minimum, the focus lever 301 is set to an upper-end position (an upper-limit position where the focus lever 301 cannot turn upward any more) of the slit 302 a to displace the moving lens group 305 to an on-focus position, thereby bringing a projected image into proper focus. In addition, if the projector is located at the longest throw distance H with which the projection size becomes maximum, the focus lever 301 is set to a lower-end position (a lower-limit position where the focus lever 301 cannot turn downward any more) of the slit 302 a to displace the moving lens group 305 to the on-focus position, thereby bringing a projected image into proper focus.
As stated above, when the focus lever 301 turns downward, the imager module 207 moves downward and comes closer to the light axis L1 accordingly. As a result, chief ray positions of the image light at the upper and down ends emitted from the lens unit 300 (hereinafter, “chief ray positions at the upper and lower ends” abbreviated as “light positions”) are changed from ray positions shown by dotted lines in FIG. 3B to ray positions shown by solid lines in FIG. 3B. More specifically, the ray positions of the image light from the lens unit 300 become closer to the light axis L1, and the incident position of the image light on the reflective mirror 400 is shifted upward accordingly. This lowers the ray positions of the image light reflected by the reflective mirror 400 and headed toward the screen. Accordingly, the position of the image projected onto the screen comes down.
More specifically, a distance sensor 700 is disposed at a front end of the housing 100 to detect a distance between the screen and the front end of the housing 100, that is, a distance between the screen and the projector main body (hereinafter, referred to as “main body distance I”). Since the main body distance I varies with a change in the throw distance H, it is possible to make a focus adjustment and a position adjustment to a projected image in accordance with the throw distance H by making a focus adjustment and a position adjustment to a projected image in accordance with the main body distance I.
The memory 30 stores a control program for actuating the control circuit 10. The memory 30 stores a control amount table for controlling the drive motor 800. The control amount table has an amount of rotation of the drive motor 800 from the initial position to thereby move the moving lens group 305 to the on-focus position in accordance with the main body distance I (hereinafter, referred to as “on-focus rotation amount”).
When the control circuit 10 determines that the manual focus adjustment is ended from the operation of the adjustment end button 60 (S23: YES), the control circuit 10 detects a distance D between a wall surface in front of the projector (hereinafter, referred to as “reference surface”) and the projector main body with the use of the distance sensor 700 (S24). Then, the control circuit 10 stores the detected distance D from the reference surface as projector initial position information in the memory 30 (S25). This completes the initial position setup mode.
The imager module 235 is a module formed by three polarized beam splitters (PBS) 226, 227, and 228, three LCOS's 229, 230, and 231, two λ/2 plate 232 and 233, a dichroic prism 234, and polarizers (not shown) disposed on incident planes of the PBS's 226, 227, and 228.
Thus, the modulated R light passes through the PBS 226 in the polarization direction, and passes through the λ/2 plate 232 to thereby further rotate the polarization direction, and then enters the dichroic prism 234.
Thus, the modulated B light passes through the PBS 228 in the polarization direction, and passes through the λ/2 plate 223 to thereby further rotate the polarization direction, and then enters the dichroic prism 234.
After having been modulated by the LOCS's 229, 230, and 231 and then having passes through the PBS 226, 227, and 228, the R, G and B lights are turned into P polarized lights with respect to the dichroic prism 234. In this arrangement, an S polarized light is higher than a P polarized light in reflectivity at a wider wavelength band due to characteristics of a dielectric multilayer structure of a dichroic prism. Accordingly, in the dichroic prism 234, the G light is higher in transmission efficiency, but the R and B lights become lower in reflection efficiency since they are P polarized lights. Thus, in the optical engine 220 of FIG. 13A, the R and B lights are allowed to pass through the λ/2 plates 223 and 224 so as to turn into S polarized lights, thereby increasing reflection efficiencies of the R and B lights at the dichroic prism 234.
The imager module 288 is a module formed by a 3-digital micro-mirror device (DMD) color separation/combination prism 284 including a TIR prim 284 a, and DMDs 285, 286, and 287.
Light emitted from the light source 281 is equalized in illuminance distribution by the rod integrator 282, and then is entered through the relay lens group 283 into the TIR prism 284 a of the 3-DMD color separation/combination prism 284. For example, JP 2006-79080 A describes a detailed configuration of the 3-DMD color separation/combination prism 284.
The light entered into the 3-DMD color separation/combination prism 284 is separated by dichroic films 284 b and 284 c constituting the 3-DMD color separation/combination prism 284, and the separated lights are entered into the DMDs 285, 286, and 287. The R, G, and B lights modulated by the DMDs 285, 286, and 287 are unified in light path by the 3-DMD color separation/combination prism 284, and the image light combined from the three color lights is entered from the TIR 284 a into the lens unit 300.
FIGS. 16A, 16B, and 16C show an arrangement example of a displacement means in place of the Z axis stage 600, 650. FIG. 16A is a perspective view of a lifting/lowering device 660 in this arrangement example, and FIG. 16B is a perspective view of a fixing member 680. FIG. 16C is a cross-section view of FIG. 16A taken along a line A-A′ for describing a configuration of a linear guide 690.
The base member 670 includes a pedestal 671, and a support plate 672 that extends vertically (upward) with respect to the pedestal 671. The pedestal 671 has attachment holes 671 a on right and left sides of a rear end (shown on the right side only). The base member 670 is screwed at predetermined positions in the housing 100 through the attachment holes 671 a. The fixing member 680 is attached to a rear side of the support plate 672 via the right and left linear guides 690 (shown on the right side only).
The fixing member 680 includes a flat-plate part 681 that is disposed along the support plate 672. The flat-plate part 681 has an opening 681 a through which image light from the imager module 207 passes.
A reception part 682 a is integrated at a base portion with the underside of the placement part 682 such that the reception part 682 a is linked to the flat-plate part 681, thereby enhancing strength of the base portion of the placement part 682. In addition, an attachment boss 682 b is formed on the underside of the placement part 682 so that the imager module 207 can be screwed to a leading end of the placement part 682. Further, a reinforcement rib 682 c is formed so as to connect the reception part 682 a and the attachment boss 682 b. In addition, two reinforcement ribs 682 d connecting to the reception part 682 a are formed on both sides of the reinforcement rib 682 c. These reinforcement ribs 682 c and 682 d are both formed along a direction in which the placement part 682 projects from the flat-plate part 681.
As stated above, the placement part 682 is reinforced by the reception part 682 a, the attachment boss 682 b, and the reinforcement ribs 682 c and 682 d. This prevents that the leading end of the placement part 682 is deformed downward under the weight of the imager module 207. In addition, the imager module 207 generates high heat by applied light. Therefore, the placement part 682 is prone to be heated at a high temperature, but the foregoing reinforcement components prevent thermal deformation of the placement part 682.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS5741057 *Apr 22, 1996Apr 21, 1998Goldberg; Gerald K.Device for displaying a projected imageUS5798864 *Feb 16, 1995Aug 25, 1998Olympus Optical Co., Ltd.Projection type image display apparatusUS20050099609 *Nov 3, 2004May 12, 2005Tomonari MasuzawaProjector with auto focus deviceJP2006235516A Title not availableJPH05100312A Title not available* Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS20120229771 *Feb 15, 2012Sep 13, 2012Seiko Epson CorporationProjector and image display systemUS20160154294 *Nov 12, 2015Jun 2, 2016Tetsuya FujiokaImage projection device and image projection method* Cited by examinerClassifications U.S. Classification353/101, 348/745International ClassificationG03B21/14, H04N3/22Cooperative ClassificationG03B3/00European ClassificationG03B3/00Legal EventsDateCodeEventDescriptionApr 20, 2009ASAssignmentOwner name: SANYO ELECTRIC CO., LTD., JAPANFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:AMANO, RYUHEI;REEL/FRAME:022568/0712Effective date: 20090409Nov 20, 2015REMIMaintenance fee reminder mailedApr 10, 2016LAPSLapse for failure to pay maintenance feesMay 31, 2016FPExpired due to failure to pay maintenance feeEffective date: 20160410RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services