Patent US5420655A successfully refreshed from Google Patents.
US5420655A
Expired / Lapsed
US
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Color projection system employing reflective display devices and prism illuminators
Assignee: Philips North America LLC
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Filing: 1992-12-16
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Granted: 1995-05-30
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Expires: 2012-12-16
Abstract
Abstract In a color projection display system employing display devices operating in the reflective mode, the optical path lengths are considerably reduced by employing prism illuminators immediately adjacent the display devices to illuminate the reflective display surface and to spatially separate the incident and reflected illumination. Such color projection systems are easier to arrange and offer sufficient brightness to be useful in both home and commercial applications, such as movie theaters.
Inventors
- 👤 Jeffrey A. Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:58
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105; G; G02; G02B; G02B26/00; G02B26/08; G02B26/0816
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
148 words
A color projection display apparatus comprising; (a) a white illumination source; (b) means for splitting an illumination beam from the source into at least two sub-beams; (c) at least two DMD display devices having a reflective display surface and operating in the reflective mode; (d) a prism illuminator for each display device, each prism illuminator consisting of: (i) a first prism with a first input face, a second illumination face, and a third output face; and (ii) a second prism having a first input face and a second output face; the illumination face of the first prism directly adjacent to the reflective display surface of a display device; (e) means for directing the sub-beams to the input faces of the prism illuminators; (f) means for recombining the sub-beams from the output faces of the prim illuminators; and (g) means for projecting the recombined sub-beams to a display screen.
Claim 2
Dependent Claim
148 words
A color projection display apparatus comprising; (a) a white illumination source; (b) means for splitting an illumination beam from the source into at least two sub-beams; (c) at least two DMD display devices having a reflective display surface and operating in the reflective mode; (d) a prism illuminator for each display device, each prism illuminator consisting of: (i) a first prism with a first input face, a second illumination face, and a third output face; and (ii) a second prism having a first input face and a second output face; the illumination face of the first prism directly adjacent to the reflective display surface of a display device; (e) means for directing the sub-beams to the input faces of the prism illuminators; (f) means for recombining the sub-beams from the output faces of the prim illuminators; and (g) means for projecting the recombined sub-beams to a display screen.
Claim 3
Dependent Claim
12 words
The apparatus of claim 1 in which there are three display devices.
Claim 4
Dependent Claim
88 words
The apparatus of claim 2 in which; (a) the means for splitting the illumination beam into sub-beams comprises a first separation filter for splitting the illumination beam into a red beam and a blue-green beam, and a second separation filter for splitting the blue-green beam into a blue beam and a green beam; (b) the means for recombining the sub-beams comprises a first recombination filter for recombining the blue and green sub-beams into a blue-green sub-beam, and a second recombination filter for recombining the blue-green and red sub-beams.
Claim 5
Dependent Claim
30 words
The apparatus of claim 3 in which the display devices are located at substantially equal path lengths from the source, and at substantially equal path lengths from the projecting means.
Claim 6
Dependent Claim
21 words
The apparatus of claim 1 in which field lenses are located adjacent the input and output faces of the prism illuminators.
Claim 7
Dependent Claim
14 words
The apparatus of claim 1 in which the source is a Xenon arc lamp.
Claim 8
Dependent Claim
15 words
The apparatus of claim 3 in which the separation and recombination filters are dichroic filters.
Claim 9
Dependent Claim
218 words
A color projection display apparatus comprising; (a) a white illumination source; (b) means for splitting an illumination beam from the source into at least two sub-beams; (c) at least two display devices having a reflective display surface and operating in the reflective mode; (d) a prism illuminator for each display device, each prism illuminator consisting of: (i) a first prism with a first input face, a second illumination face, and a third output face; (ii) a second prism having a first input face and a second output face; the third output face of the first prism facing the first input face of the second prism and the illumination face of the first prism directly adjacent to the reflective display surface of a display device; (e) means for directing the sub-beams to the input faces of the prism illuminators; (f) means for recombining the sub-beams from the output faces of the prism illuminators; and (g) means for projecting the recombined sub-beams to a display screen and (h) field lenses located adjacent to input and output faces of the prism illuminators, the display devices located at substantially equal path lengths from the source, and at substantially equal path lengths from the projecting means and each sub-beam from each prism illuminator being independently directed to said means for combining the sub-beams.
Claim 10
Dependent Claim
218 words
A color projection display apparatus comprising; (a) a white illumination source; (b) means for splitting an illumination beam from the source into at least two sub-beams; (c) at least two display devices having a reflective display surface and operating in the reflective mode; (d) a prism illuminator for each display device, each prism illuminator consisting of: (i) a first prism with a first input face, a second illumination face, and a third output face; (ii) a second prism having a first input face and a second output face; the third output face of the first prism facing the first input face of the second prism and the illumination face of the first prism directly adjacent to the reflective display surface of a display device; (e) means for directing the sub-beams to the input faces of the prism illuminators; (f) means for recombining the sub-beams from the output faces of the prism illuminators; and (g) means for projecting the recombined sub-beams to a display screen and (h) field lenses located adjacent to input and output faces of the prism illuminators, the display devices located at substantially equal path lengths from the source, and at substantially equal path lengths from the projecting means and each sub-beam from each prism illuminator being independently directed to said means for combining the sub-beams.
Claim 11
Dependent Claim
203 words
A color projection display apparatus comprising; (a) a white illumination source; (b) means for splitting an illumination beam from the source into at least two sub-beams; (c) at least two display devices having a reflective display surface and operating in the reflective mode; (d) a prism illuminator for each display device, each prism illuminator consisting of: (i) a first prism with a first input face, a second illumination face, and a third output face; (ii) a second prism having a first input face and a second output face; the third output face of the first prism facing the first input face of the second prism and the illumination face of the first prism directly adjacent to the reflective display surface of a display device; (e) means for directing the sub-beams to the input faces of the prism illuminators; (f) means for recombining the sub-beams from the output faces of the prism illuminators; and (g) means for projecting the recombined sub-beams to a display screen, the display devices located at substantially equal path lengths from the source, and at substantially equal path lengths from the projecting means and each sub-beam from each prism illuminator being independently directed to said means for recombining the sub-beams.
Claim 12
Dependent Claim
203 words
A color projection display apparatus comprising; (a) a white illumination source; (b) means for splitting an illumination beam from the source into at least two sub-beams; (c) at least two display devices having a reflective display surface and operating in the reflective mode; (d) a prism illuminator for each display device, each prism illuminator consisting of: (i) a first prism with a first input face, a second illumination face, and a third output face; (ii) a second prism having a first input face and a second output face; the third output face of the first prism facing the first input face of the second prism and the illumination face of the first prism directly adjacent to the reflective display surface of a display device; (e) means for directing the sub-beams to the input faces of the prism illuminators; (f) means for recombining the sub-beams from the output faces of the prism illuminators; and (g) means for projecting the recombined sub-beams to a display screen, the display devices located at substantially equal path lengths from the source, and at substantially equal path lengths from the projecting means and each sub-beam from each prism illuminator being independently directed to said means for recombining the sub-beams.
Claim 13
Dependent Claim
12 words
The apparatus of claim 9 in which there are three display devices.
Claim 14
Dependent Claim
88 words
The apparatus of claim 10 in which; (a) the means for splitting the illumination beam into sub-beams comprises a first separation filter for splitting the illumination beam into a red beam and a blue-green beam, and a second separation filter for splitting the blue-green beam into a blue beam and a green beam; (b) the means for recombining the sub-beams comprises a first recombination filter for recombining the blue and green sub-beams into a blue-green sub-beam, and a second recombination filter for recombining the blue-green and red sub-beams.
Claim 15
Dependent Claim
14 words
The apparatus of claim 9 in which the source is a Xenon arc lamp,
Claim 16
Dependent Claim
15 words
The apparatus of claim 11 in which the separation and recombination filters are dichroic filters,
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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) | 1998-05-29 | 1998-11-28 | 1999-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-29 | 2002-11-28 | 2003-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-29 | 2006-11-28 | 2007-05-30 | $7700.00 | Window Closed / Lapsed |