Patent US5743612A successfully refreshed from Google Patents.
US5743612A
Expired / Lapsed
US
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Liquid crystal projector
Assignee: Hitachi Ltd
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Filing: 1996-11-04
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Granted: 1998-04-28
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Expires: 2016-11-04
Abstract
Abstract In a liquid crystal projector using a reflective and scattering or reflective type liquid crystal panel, a plurality of light sources are used, thereby securing sufficient brightness of an image, increasing the F-number of a projection lens, and miniaturizing and lightening the projector. A light source is arranged right next to the projection lens and an exhaust port is arranged on the front face of the projector, thereby preventing hot heat discharged from the exhaust port from being discharged toward peripheral equipment or the operator.
Inventors
- 👤 Yutaka Matsuda
- 👤 Nobuhiro Konuma
- 👤 Kenji Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:36
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105; H04N9/3141; H04N9/315; H04N9/3164
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
74 words
A liquid crystal projector comprising: at least two lights sources; a dichroic prism; and three reflective type liquid crystal panels, in which illumination light from one or more of the light sources are allowed to enter the reflective types liquid crystal panels and are modulated to image lights by the reflective type liquid crystal panels and reflected, and the image lights from the reflective type liquid crystal panels are enlargedly projected onto a screen.
Claim 2
Dependent Claim
74 words
A liquid crystal projector comprising: at least two lights sources; a dichroic prism; and three reflective type liquid crystal panels, in which illumination light from one or more of the light sources are allowed to enter the reflective types liquid crystal panels and are modulated to image lights by the reflective type liquid crystal panels and reflected, and the image lights from the reflective type liquid crystal panels are enlargedly projected onto a screen.
Claim 3
Dependent Claim
145 words
A liquid crystal projector comprising: a light source; a reflective type liquid crystal panel; a projection lens; a mirror arranged in an optical path between the light source and the reflective type liquid crystal panel; and an aperture diaphragm arranged in an optical path between the reflective type liquid crystal panel and the projection lens, in which an illumination light from the light source is allowed to enter the reflective type liquid crystal panel via the mirror on the light source side and is modulated to an image light by the reflective type liquid crystal panel and is reflected, and the image light from the reflective type liquid crystal panel is allowed to enter the projection lens through the aperture diaphragm on the projection lens side and is enlargedly projected onto a screen by the projection lens, wherein at least two light sources are provided.
Claim 4
Dependent Claim
145 words
A liquid crystal projector comprising: a light source; a reflective type liquid crystal panel; a projection lens; a mirror arranged in an optical path between the light source and the reflective type liquid crystal panel; and an aperture diaphragm arranged in an optical path between the reflective type liquid crystal panel and the projection lens, in which an illumination light from the light source is allowed to enter the reflective type liquid crystal panel via the mirror on the light source side and is modulated to an image light by the reflective type liquid crystal panel and is reflected, and the image light from the reflective type liquid crystal panel is allowed to enter the projection lens through the aperture diaphragm on the projection lens side and is enlargedly projected onto a screen by the projection lens, wherein at least two light sources are provided.
Claim 5
Dependent Claim
13 words
The projector according to claim 2, wherein at least two mirrors are arranged.
Claim 6
Dependent Claim
56 words
The projector according to claim 3, wherein a set of the aperture diaphragm and the mirror is positioned on an oblique line, another set of the aperture diaphragm and the mirror is positioned on another oblique line, the oblique lines cross each other with respect to an optical axis of the projection lens as a center.
Claim 7
Dependent Claim
72 words
The projector according to claim 2, wherein two light sources are used, two mirrors are adjacent in the vertical or horizontal direction within a focal plane of the projection lens and occupy about half of the focal plane of the projection lens, and two aperture diaphragms are adjacently arranged in the horizontal or vertical direction on the opposite side to the mirrors with respect to the optical axis of the projection lens.
Claim 8
Dependent Claim
25 words
The projector according to claim 5, wherein adjacent portions of the adjacent aperture diaphragms are blended, thereby making a long shape in the neighboring direction.
Claim 9
Dependent Claim
14 words
The projector according to claim 5, wherein shapes of the aperture diaphragms are different.
Claim 10
Dependent Claim
30 words
The projector according to claim 6, wherein the shape of the aperture diaphragm is almost a quarter of a circle and the blended aperture diaphragms have an almost semicircular shape.
Claim 11
Dependent Claim
41 words
The projector according to claim 2, wherein only light sources of an optional number among provided light sources are turned on and a mechanism for closing the aperture diaphragm corresponding to a light source which is not turned on is provided.
Claim 12
Dependent Claim
60 words
The projector according to claim 2, wherein an exhaust port from which residual heat from the light source is discharged is positioned on the front face of the projector, on which a light-outgoing face of the projection lens is also positioned, and a discharging direction of the exhaust is almost the same as an outgoing direction of the image light.
Claim 13
Dependent Claim
18 words
The projector according to claim 10, wherein the light source is arranged almost next to the projection lens.
Claim 14
Dependent Claim
145 words
A liquid crystal projector comprising: a light source; a reflective type liquid crystal panel; a projection lens; an aperture diaphragm arranged in an optical path between the light source and the reflective type liquid crystal panel; and a mirror arranged in an optical path between the reflective type liquid crystal panel and the projection lens, in which an illumination light from the light source is allowed to enter the reflective type liquid crystal panel through the aperture diaphragm on the light source side and is modulated to an image light by the reflective type liquid crystal panel and is reflected, and the image light from the reflective type liquid crystal panel is allowed to enter the projection lens via the mirror on the projection lens side and is enlargedly projected onto a screen by the projection lens, wherein at least two light sources are provided.
Claim 15
Dependent Claim
145 words
A liquid crystal projector comprising: a light source; a reflective type liquid crystal panel; a projection lens; an aperture diaphragm arranged in an optical path between the light source and the reflective type liquid crystal panel; and a mirror arranged in an optical path between the reflective type liquid crystal panel and the projection lens, in which an illumination light from the light source is allowed to enter the reflective type liquid crystal panel through the aperture diaphragm on the light source side and is modulated to an image light by the reflective type liquid crystal panel and is reflected, and the image light from the reflective type liquid crystal panel is allowed to enter the projection lens via the mirror on the projection lens side and is enlargedly projected onto a screen by the projection lens, wherein at least two light sources are provided.
Claim 16
Dependent Claim
102 words
A liquid crystal projector comprising a light source, a liquid crystal panel, and a projection lens, in which an illumination light emitted from the light source is modulated to an image light by the liquid crystal panel and the image light is enlargedly projected by the projection lens, wherein an exhaust port from which residual heat from the light source is discharged is positioned on the front face of the projector, on which a light-outgoing face of the projection lens is also arranged, and a discharging direction of the exhaust is almost the same as the outgoing direction of the image light.
Claim 17
Dependent Claim
102 words
A liquid crystal projector comprising a light source, a liquid crystal panel, and a projection lens, in which an illumination light emitted from the light source is modulated to an image light by the liquid crystal panel and the image light is enlargedly projected by the projection lens, wherein an exhaust port from which residual heat from the light source is discharged is positioned on the front face of the projector, on which a light-outgoing face of the projection lens is also arranged, and a discharging direction of the exhaust is almost the same as the outgoing direction of the image light.
Claim 18
Dependent Claim
14 words
The projector according to claim 5, wherein sizes of the aperture diaphragms are different.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-04-27 | 2001-10-27 | 2002-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-04-27 | 2005-10-27 | 2006-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-04-27 | 2009-10-27 | 2010-04-28 | $7700.00 | Window Closed / Lapsed |