US4644287A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low noise synchronous detection for a charge transfer device
Assignee: RCA Corp
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Filing: 1986-03-10
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Granted: 1987-02-17
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Expires: 2006-03-10
Abstract
Abstract Charge transfer device output signals typically include an information component which is contaminated with both on-chip amplifier noise and reset noise. For reducing these noise components, the device output signal is applied to first and second synchronous detectors. The first synchronous detector is responsive to a first reference carrier signal for maximizing at its output the information component while the second synchronous detector is responsive to a second reference carrier for maximizing at its output the noise components. The synchronous detector output signals are then differentially combined so as to substantially reduce the noise components from the contaminated information component.
Inventors
- 👤 Peter A. Levine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:58
CPC Classifications
G; G11; G11C; G11C19/00; G11C19/28; G11C19/282; G11C19/285; G11C27/00; G11C27/04; H; H04; H04N; H04N25/00; H04N25/60; H04N25/65
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
100 words
In combination with a charge transfer device, apparatus for recovering a charge transfer device output signal including an information component contaminated with a noise component, comprising: first and second synchronous detectors each responsive to said device output signal; said first synchronous detector being responsive to a first reference carrier signal for detecting said information component contaminated with noise and said second synchronous detector being responsive to a second reference carrier for detecting substantially only said noise component; and means for differentially combining the outputs of said first and second detectors for reducing said noise component from said contaminated information component.
Claim 2
Dependent Claim
100 words
In combination with a charge transfer device, apparatus for recovering a charge transfer device output signal including an information component contaminated with a noise component, comprising: first and second synchronous detectors each responsive to said device output signal; said first synchronous detector being responsive to a first reference carrier signal for detecting said information component contaminated with noise and said second synchronous detector being responsive to a second reference carrier for detecting substantially only said noise component; and means for differentially combining the outputs of said first and second detectors for reducing said noise component from said contaminated information component.
Claim 3
Dependent Claim
17 words
Apparatus according to claim 1 wherein: said first and second synchronous detectors each comprise respective balanced modulators.
Claim 4
Dependent Claim
35 words
Apparatus according to claim 1 further including: first and second filter means for suppressing at least the baseband portion of the device output signal before it is applied to said first and second synchronous detectors.
Claim 5
Dependent Claim
15 words
Apparatus according to claim 1 wherein: said means for differentially combining comprises a differential amplifier.
Claim 6
Dependent Claim
15 words
Apparatus according to claim 2 wherein: said means for differentially combining comprises a differential amplifier.
Claim 7
Dependent Claim
34 words
Apparatus according to claim 2 further including a low pass filter coupled to the output of said means for differentially combining for passing substantially only the baseband component of said synchronous detector output signals.
Claim 8
Dependent Claim
34 words
Apparatus according to claim 3 further including a low pass filter coupled to the output of said means for differentially combining for passing substantially only the baseband component of said synchronous detector output signals.
Claim 9
Dependent Claim
15 words
Apparatus according to claim 3 wherein: said means for differentially combining comprises a differential amplifier.
Claim 10
Dependent Claim
16 words
Apparatus according to claim 3 wherein: said first and second filter means each comprise bandpass filters.
Claim 11
Dependent Claim
25 words
Apparatus according to claim 9 wherein: said bandpass filters have a passband selected to pass fundamental signal components of said charge transfer device output signal.
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) | 1990-02-16 | 1990-08-18 | 1991-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-16 | 1994-08-18 | 1995-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-16 | 1998-08-18 | 1999-02-17 | $7700.00 | Window Closed / Lapsed |