US5654775A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Three lamp, three light valve projection system
Assignee: Philips North America LLC
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Filing: 1995-12-27
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Granted: 1997-08-05
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Expires: 2015-12-27
Abstract
Abstract In a three lamp, three light valve projection system, the lamps are energized sequentially in a three phase illumination cycle. The light therefrom is separated by an optical system composed of a three by three array of nine mirrors, all but one of which must be dichroic, to produce red, green, blue color sequential illumination of each light valve. Each light valve, which is controlled by a different control signal derived from an input video signal, is illuminated by a different color sequence such that during each phase of the illumination cycle, each light valve is illuminated by a different color. When the output beams from the light valves are converged over the same area of a screen, the phases of the illumination cycle occur at the field rate of the input video signal, whereas, when the output beams are arranged to produce a tiled image, the phases of the illumination cycle occur at three times the field rate.
Inventors
- 👤 Matthew Scott Brennesholtz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:53
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/12; H04N9/31; H04N9/3102; H04N9/3105; H04N9/3141; H04N9/315; H04N9/3155; H04N9/3164
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
145 words
A projection system in which three output light beams are formed for projection on a screen in accordance with an illumination cycle having three phases for displaying a video image in response to an input video signal, said system comprising: three light sources which are sequentially activatable during respective different phases of the illumination cycle; three light valves positioned for controlling respective different ones of the output light beams in response to said input video signal; and an optical system intermediate the three light sources and the three light valves for separating light from each light source into three colors and directing the light of each color separated from the same light source to a different one of the three light valves, in a manner that each light valve sequentially receives input light in a different sequence of the three colors during the illumination cycle.
Claim 2
Dependent Claim
145 words
A projection system in which three output light beams are formed for projection on a screen in accordance with an illumination cycle having three phases for displaying a video image in response to an input video signal, said system comprising: three light sources which are sequentially activatable during respective different phases of the illumination cycle; three light valves positioned for controlling respective different ones of the output light beams in response to said input video signal; and an optical system intermediate the three light sources and the three light valves for separating light from each light source into three colors and directing the light of each color separated from the same light source to a different one of the three light valves, in a manner that each light valve sequentially receives input light in a different sequence of the three colors during the illumination cycle.
Claim 3
Dependent Claim
40 words
The projection system as claimed in claim 1, further comprising means for converging the three output light beams projected onto the screen and wherein the phases of the illumination cycle occur at the field rate of the input video signal.
Claim 4
Dependent Claim
37 words
The projection system as claimed in claim 1, further comprising means for tiling the three output light beams projected onto the screen and wherein the illumination cycle occurs at the field rate of the input video signal.
Claim 5
Dependent Claim
32 words
The projection system as claimed in claim 1, wherein said optical system has a same optical path length from each of the three light sources to each of the three light valves.
Claim 6
Dependent Claim
34 words
The projection system of claim 4, further comprising another optical system intermediate the light valves and the screen providing a same optical path length from each of the three light valves to the screen.
Claim 7
Dependent Claim
32 words
The projection system as claimed in claim 2, wherein said optical system has a same optical path length from each of the three light sources to each of the three light valves.
Claim 8
Dependent Claim
34 words
The projection system of claim 6, further comprising another optical system intermediate the light valves and the screen providing a same optical path length from each of the three light valves to the screen.
Claim 9
Dependent Claim
37 words
The projection system as claimed in claim 3, wherein said optical system has a same optical path length along nine optical paths directed from each of the three light sources to each of the three light valves.
Claim 10
Dependent Claim
34 words
The projection system of claim 4, further comprising another optical system intermediate the light valves and the screen providing a same optical path length from each of the three light valves to the screen.
Claim 11
Dependent Claim
52 words
The projection system as claimed in claim 1, further comprising: means for sequentially activating the three light sources during the respective different phases of the illumination cycle; and means for converting the input video signal to three different color sequential control signals, each controlling a different one of the three light valves.
Claim 12
Dependent Claim
52 words
The projection system as claimed in claim 2, further comprising: means for sequentially activating the three light sources during the respective different phases of the illumination cycle; and means for converting the input video signal to three different color sequential control signals, each controlling a different one of the three light valves.
Claim 13
Dependent Claim
52 words
The projection system as claimed in claim 3, further comprising: means for sequentially activating the three light sources during the respective different phases of the illumination cycle; and means for converting the input video signal to three different color sequential control signals, each controlling a different one of the three light valves.
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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) | 2000-08-04 | 2001-02-03 | 2001-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-08-04 | 2005-02-03 | 2005-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-08-04 | 2009-02-03 | 2009-08-05 | $7700.00 | Window Closed / Lapsed |