Patent US2171692A successfully refreshed from Google Patents.
Patent US3627909A successfully refreshed from Google Patents.
US3627909A
Expired / Lapsed
US
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Coherent color generator for light valve projection system
Assignee: General Electric Co
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Filing: 1970-01-28
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Granted: 1971-12-14
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Expires: 1990-01-28
Abstract
Abstract Radio frequency carrier signals to establish optical diffraction gratings of predetermined spatial frequency for each primary color respectively employed in a light valve are generated by a gated master oscillator and frequency divider apparatus. The carrier frequency ratios are constant, and all oscillations begin simultaneously from a zero crossing, with full amplitude oscillation occurring immediately at the outset. Phase alternation at vertical field rate is introduced in one of the carrier signals to alternately establish diffraction gratings oriented in the same direction and having identical spatial frequency but opposite spatial phase in order to minimize optical beat frequencies between the first and second diffraction gratings.
Inventors
- 👤 Thomas P L Liu
- 👤 Ho-Chol Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:52
CPC Classifications
H; H04; H04N; H04N5/00; H04N5/74; H04N5/7416; H04N5/7425; H04N25/00; H04N25/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
175 words
A system for generating coherent radio frequency carrier signals to establish, within a raster generated by a scanning electron beam, optical diffraction gratings of predetermined spatial frequency for each respective primary color utilized in images to be optically projected onto a remote display surface by directing light onto said diffraction gratings so as to modulate said light with information requisite to formation of said images, said system comprising: oscillator means producing a signal of substantially constant frequency; frequency divider means coupled to said oscillator means; pulse generator means coupled to said frequency divider means for resetting said frequency divider means to ensure that each output signal produced by said frequency divider means begins with full amplitude at a desired phase angle with respect to the signal produced by said oscillator means, said pulse generator means being actuated upon completion of each horizontal scan of said electron beam; and gating means coupled to said oscillator means for maintaining said oscillator means disabled during each interval in which said pulse generator means resets said frequency divider means.
Claim 2
Independent Claim
175 words
A system for generating coherent radio frequency carrier signals to establish, within a raster generated by a scanning electron beam, optical diffraction gratings of predetermined spatial frequency for each respective primary color utilized in images to be optically projected onto a remote display surface by directing light onto said diffraction gratings so as to modulate said light with information requisite to formation of said images, said system comprising: oscillator means producing a signal of substantially constant frequency; frequency divider means coupled to said oscillator means; pulse generator means coupled to said frequency divider means for resetting said frequency divider means to ensure that each output signal produced by said frequency divider means begins with full amplitude at a desired phase angle with respect to the signal produced by said oscillator means, said pulse generator means being actuated upon completion of each horizontal scan of said electron beam; and gating means coupled to said oscillator means for maintaining said oscillator means disabled during each interval in which said pulse generator means resets said frequency divider means.
Claim 3
Dependent Claim
44 words
The system of claim 1 wherein said frequency divider means comprises first and second frequency counters producing signals of respectively different submultiple frequencies of said substantially constant frequency, and said pulse generator means is coupled to each of said first and second frequency counters.
Claim 4
Dependent Claim
68 words
The system of claim 2 wherein said second frequency counter produces first and second output signals of identical frequency but opposite phase, said system further including means coupled to said second frequency counter for controllably selecting one or the other of said first and second output signals therefrom at a frequency rate corresponding to the frequency rate at which image fields are produced by said system for display.
Claim 5
Dependent Claim
25 words
The system of claim 2 including tuned amplifier means coupled to said first and second frequency counters in order to produce a sinusoidal output signal.
Claim 6
Dependent Claim
25 words
The system of claim 3 including tuned amplifier means coupled to said first and second frequency counters in order to produce a sinusoidal output signal.
Claim 7
Dependent Claim
67 words
The system of claim 2 wherein each of said first and second frequency counters comprises a pair of bistable circuits, one bistable circuit of each pair of said bistable circuits producing output pulses from each of said first and second frequency counters respectively, each said one of said bistable circuits producing a first output pulse upon occurrence of each initial output signal cycle from said oscillator means.
Claim 8
Dependent Claim
33 words
The system of claim 1 including means coupled jointly to said pulse generator means and said gating means in order to prevent said oscillator means and said pulse generator means from operating simultaneously.
Claim 9
Dependent Claim
33 words
The system of claim 2 including means coupled jointly to said pulse generator means and said gating means in order to prevent said oscillator means and said pulse generator means from operating simultaneously.
Claim 10
Dependent Claim
78 words
The system of claim 6 wherein said one bistable circuit of said second frequency counter produces first and second output signals of identical frequency but opposite phase, said system further including means coupled to said one bistable circuit of said second frequency counter for controllably selecting one or the other of said first and second output signals therefrom at a frequency rate corresponding to the frequency rate at which image fields are produced by said system for display.
References Cited (Backward Citations)
US3325592A
Cited
US3401343A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-13 | 1975-06-14 | 1975-12-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-13 | 1979-06-14 | 1979-12-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-13 | 1983-06-14 | 1983-12-14 | $7700.00 | Window Closed / Lapsed |