Patent US2867792A successfully refreshed from Google Patents.
Patent US3593151A successfully refreshed from Google Patents.
US3593151A
Expired / Lapsed
US
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Detector for receiver printer startup
Assignee: Xerox Corp
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Filing: 1968-08-12
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Granted: 1971-07-13
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Expires: 1988-08-12
Abstract
Abstract A detector for controlling the startup of a facsimile printing transducer. The detector includes a comparator which activates the transducer when a FM carrier signal of a first frequency is received and enables the facisimile transducer to continue operation until the carrier signal falls below a second frequency corresponding to an adjusted bias applied to the comparator input when the carrier signal of said first frequency is received.
Inventors
- 👤 John R Veale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:05
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/32; H04N1/327
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
157 words
Apparatus for generating a signal indicating that a signal of a frequency within a predetermined frequency range has been received comprising: comparator means for generating said indicating signal when the signal received at the input thereof is of a frequency equal to a frequency corresponding to the bias signals applied to said input, first means for generating a first bias signal corresponding to a signal of a first frequency within said predetermined frequency range and connected to the input of said comparator means, second means connected to said comparator means input for generating a second bias signal corresponding to a signal of a second frequency when a signal of said first frequency is received, means for coupling said indicating signal to said second generating means, the bias signal applied to the input of said comparator means being equal to the sum of said first and second bias signals after a signal of said first frequency is received.
Claim 2
Dependent Claim
157 words
Apparatus for generating a signal indicating that a signal of a frequency within a predetermined frequency range has been received comprising: comparator means for generating said indicating signal when the signal received at the input thereof is of a frequency equal to a frequency corresponding to the bias signals applied to said input, first means for generating a first bias signal corresponding to a signal of a first frequency within said predetermined frequency range and connected to the input of said comparator means, second means connected to said comparator means input for generating a second bias signal corresponding to a signal of a second frequency when a signal of said first frequency is received, means for coupling said indicating signal to said second generating means, the bias signal applied to the input of said comparator means being equal to the sum of said first and second bias signals after a signal of said first frequency is received.
Claim 3
Dependent Claim
40 words
The apparatus as defined in claim 1 wherein the indicating signal is maintained if a subsequently received signal is of a frequency equal to or greater than a frequency corresponding to the sum of said first and second bias signals.
Claim 4
Dependent Claim
37 words
The apparatus as defined in claim 2 wherein the indicating signal is removed if a subsequently received signal is of a frequency less than a frequency corresponding to the sum of said first and second bias signals.
Claim 5
Independent Claim
147 words
A method of generating a signal indicating that a signal of a frequency within a predetermined frequency range has been received comprising the steps of: a. comparing a signal derived from a received signal having a first frequency with a bias signal corresponding to a second frequency within said predetermined frequency range, b. generating said indicating signal at the output of said comparator when said first frequency equals said bias signal, c. producing a second bias signal when said indicating signal is generated, and d. comparing a signal derived from a subsequently received signal with a bias signal equal to the sum of said first and second bias signals, said first and second bias signals corresponding to a third frequency within said predetermined frequency range, said indicating signal being generated when said signal derived from said subsequently received signal is at least equal to said third frequency.
Claim 6
Independent Claim
147 words
A method of generating a signal indicating that a signal of a frequency within a predetermined frequency range has been received comprising the steps of: a. comparing a signal derived from a received signal having a first frequency with a bias signal corresponding to a second frequency within said predetermined frequency range, b. generating said indicating signal at the output of said comparator when said first frequency equals said bias signal, c. producing a second bias signal when said indicating signal is generated, and d. comparing a signal derived from a subsequently received signal with a bias signal equal to the sum of said first and second bias signals, said first and second bias signals corresponding to a third frequency within said predetermined frequency range, said indicating signal being generated when said signal derived from said subsequently received signal is at least equal to said third frequency.
Claim 7
Dependent Claim
44 words
The method as defined in claim 4 wherein said indicating signal is maintained if said signal derived from said subsequently received signal is of a frequency equal to or greater than a frequency corresponding to the sum of said first and second bias signals.
Claim 8
Dependent Claim
41 words
The method as defined in claim 5 wherein said indicating signal is removed if said signal derived from said subsequently received signal is of a frequency less than a frequency corresponding to the sum of said first and second bias signals.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-12 | 1975-01-11 | 1975-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-12 | 1979-01-11 | 1979-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-12 | 1983-01-11 | 1983-07-13 | $7700.00 | Window Closed / Lapsed |