Patent US4983032A successfully refreshed from Google Patents.
US4983032A
Expired / Lapsed
US
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Projection system
Assignee: US Philips Corp
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Filing: 1990-01-12
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Granted: 1991-01-08
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Expires: 2010-01-12
Abstract
Abstract A projection system comprises a plurality of reflective LCDs (41, 42, 43) which are irradiated with colored sub-beams (21, 22, 23). The sub-beams are not perpendicularly incident on the LCDs so that the reflected beams (24, 25, 26) do not coincide with the incident beams. The sub-beams originate from a white light beam (20) which is split up into colored sub-beams by means of color-selective mirrors (31, 33). The same mirrors are used to combine the reflected beams (24, 25, 26) to a projection beam (27). An angle-dependent beam separater (80) is arranged so as to realize a spatial separation between the incident beams and the reflected beam. The angle-dependent beam separater (80) is arranged in such a way that the angle at which the beam (20) is incident on the color-selective mirrors (31, 33) is equal to the angle at which the reflected sub-beams (24, 25, 26) are incident on these mirrors.
Inventors
- 👤 Adrianus H. J. Van Den Brandt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:15
CPC Classifications
H; H01; H01J; H01J31/00; H01J31/08; H01J31/10; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
129 words
A projection system comprising a radiation source unit (10) for generating a radiation beam (20), a modulation system for modulating the radiation beam in accordance with a picture to be displayed, and a projection lens system (60) for projecting the picture to be displayed on a projection screen, said modulation system having at least one color-selective mirror (31) for splitting the radiation beam to sub-beams (21, 22) and at least a first and a second reflective light valve (41, 42) for reflecting and modulating the sub-beams (24, 25), characterized in that the axes of the radiation path of the radiation beams incident on the light valves (41, 42) and reflected by the light valves extend at an angle to the respective normals of the planes of the light valves.
Claim 2
Dependent Claim
129 words
A projection system comprising a radiation source unit (10) for generating a radiation beam (20), a modulation system for modulating the radiation beam in accordance with a picture to be displayed, and a projection lens system (60) for projecting the picture to be displayed on a projection screen, said modulation system having at least one color-selective mirror (31) for splitting the radiation beam to sub-beams (21, 22) and at least a first and a second reflective light valve (41, 42) for reflecting and modulating the sub-beams (24, 25), characterized in that the axes of the radiation path of the radiation beams incident on the light valves (41, 42) and reflected by the light valves extend at an angle to the respective normals of the planes of the light valves.
Claim 3
Dependent Claim
40 words
A projection system as claimed in claim 1, characterized in that the color-selective mirror (31, 33) is arranged in the radiation path of both the radiation beams incident on the light valves and the beams reflected by the light valves.
Claim 4
Dependent Claim
32 words
A projection system as claimed in claim 1, characterized in that the projection system comprises an angle-dependent beam separator (71, 75; 72, 76; 80) for separating the incident and reflected radiation beams.
Claim 5
Dependent Claim
36 words
A projection system as claimed in claim 3, characterized in that the color-selective mirror (31, 33) is arranged in the radiation path between the reflective light valves (41, 42, 43) and the angle-dependent beam separator (80).
Claim 6
Dependent Claim
71 words
A projection system as claimed in claim 1, characterized in that a first plane in which the axes of the radiation path of the sub-beams (22, 25) incident on the first light valve and reflected thereby are located and a second plane in which the radiation path of the sub-beams (23, 26) incident on the second light valve and reflected thereby are located, extend at an angle of more than zero.
Claim 7
Dependent Claim
53 words
A projection system as claimed in claim 5, characterized in that the said first plane and the said second plane intersect each other in accordance with the line of intersection which is parallel to a line of intersection of a plane of the color-selective mirror and a plane of a reflective light valve.
Claim 8
Dependent Claim
60 words
A projection system as claimed in claim 1, in which the modulation system has two color-selective mirrors (31, 33) for splitting the radiation beam generated by the radiation source unit into a red, a green and a blue sub-beam and three reflective light valves (41, 42, 43) for modulating the three sub-beams with parts of a picture to be displayed.
References Cited (Backward Citations)
US4127322A
Cited
US4464019A
Cited
US4850685A
Cited
US4836649A
Cited
US4749259A
Cited
US4913528A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-01-07 | 1994-07-09 | 1995-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-07 | 1998-07-09 | 1999-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-07 | 2002-07-09 | 2003-01-08 | $7700.00 | Window Closed / Lapsed |