Patent US5821992A successfully refreshed from Google Patents.
US5821992A
Expired / Lapsed
US
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Focal plane array capacitance cancellation
Assignee: Raytheon Co
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Filing: 1997-02-13
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Granted: 1998-10-13
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Expires: 2017-02-13
Abstract
Abstract A video buffer of a focal plane array (FPA) electrical interface module is presented for providing output capacitance cancellation. The buffer has a capacitance cancellation stage (50) for receiving an analog signal produced by a FPA. The cancellation stage (50) includes an amplifier having a gain greater than unity for amplifying the analog signal and positive feedback capacitor for reducing power requirements and providing an increased pixel rate for the system. A dc restoration stage (52) is included for setting the analog signal to a dc level that is required by an external system and a line driving stage (54) for driving a video cable from the buffer to the external components of the system.
Inventors
- 👤 Richard Saylor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:49
CPC Classifications
H; H04; H04N; H04N25/00; H04N25/70; H04N25/71; H04N25/75
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
110 words
A video buffer of a focal plane array (FPA) electrical interface module for providing output capacitance cancellation, comprising: a capacitance cancellation stage for receiving an analog signal produced by a FPA, said cancellation stage including an amplifier having a gain greater than unity for amplifying said analog signal, and said cancellation stage further including positive feedback means for reducing power requirements and providing an increased pixel rate for said system; a dc restoration stage for setting said analog signal to a dc level of external components of said system; and a line driving stage for driving a video cable from said video buffer to said external components of said system.
Claim 2
Dependent Claim
110 words
A video buffer of a focal plane array (FPA) electrical interface module for providing output capacitance cancellation, comprising: a capacitance cancellation stage for receiving an analog signal produced by a FPA, said cancellation stage including an amplifier having a gain greater than unity for amplifying said analog signal, and said cancellation stage further including positive feedback means for reducing power requirements and providing an increased pixel rate for said system; a dc restoration stage for setting said analog signal to a dc level of external components of said system; and a line driving stage for driving a video cable from said video buffer to said external components of said system.
Claim 3
Dependent Claim
15 words
The video buffer of claim 1 wherein said positive feedback means is a feedback capacitor.
Claim 4
Dependent Claim
43 words
The video buffer of claim 2 wherein the value of said capacitor is selected using the following relationship: ##EQU3## wherein C 1 is said capacitor, K is the gain of said amplifier, and C s is the equivalent output capacitance of said FPA.
Claim 5
Dependent Claim
17 words
The video buffer of claim 1 wherein said FPA includes a plurality of photoelectrically responsive detector elements.
Claim 6
Dependent Claim
13 words
The video buffer of claim 1 wherein said amplifier is a non-inverting amplifier.
Claim 7
Dependent Claim
23 words
The video buffer of claim 1 wherein said gain is provided with a dual resistor configuration coupled to an input of said amplifier.
Claim 8
Dependent Claim
19 words
The video buffer of claim 1 wherein said cancellation stage receives a plurality of analog signals from said FPA.
Claim 9
Dependent Claim
24 words
The video buffer of claim 7 wherein said plurality of analog signals are proportional to the flux of infrared light received by said FPA.
Claim 10
Independent Claim
113 words
A method for reducing the focal plane array output capacitance of a thermal imaging system, comprising the steps of: (a) receiving an analog signal generated by said FPA with a video buffer; (b) amplifying said signal with a video buffer amplifier having a gain greater than unity and producing an amplified analog signal; (c) feeding said amplified signal through a positive feedback means for reducing power requirements and providing an increased pixel rate for said system; (d) setting said analog signal to a dc level with a video buffer dc restoration stage; and (e) driving a video cable from said video buffer to external components of said system with an output line driver.
Claim 11
Independent Claim
113 words
A method for reducing the focal plane array output capacitance of a thermal imaging system, comprising the steps of: (a) receiving an analog signal generated by said FPA with a video buffer; (b) amplifying said signal with a video buffer amplifier having a gain greater than unity and producing an amplified analog signal; (c) feeding said amplified signal through a positive feedback means for reducing power requirements and providing an increased pixel rate for said system; (d) setting said analog signal to a dc level with a video buffer dc restoration stage; and (e) driving a video cable from said video buffer to external components of said system with an output line driver.
Claim 12
Dependent Claim
14 words
The method of claim 9 wherein said positive feedback means is a feedback capacitor.
Claim 13
Dependent Claim
42 words
The method of claim 10, further comprising the step of selecting said capacitor using the following relationship: ##EQU4## wherein C 1 is said capacitor, K is the gain of said amplifier, and C s is the equivalent output capacitance of said FPA.
Claim 14
Dependent Claim
22 words
The method of claim 9 wherein step (a) is repeated so that a plurality of analog signals are received by said buffer.
Claim 15
Dependent Claim
30 words
The method of claim 9, further comprising the step of generating said analog signal which is proportional to the flux of infrared light received by a detector of said FPA.
Claim 16
Dependent Claim
12 words
The method of claim 9 wherein said amplifier is a non-inverting amplifier.
Claim 17
Dependent Claim
65 words
The method of claim 9 further comprising the step of selecting a first resistor having a first value and a second resistor having a second value, said step of selecting said first and second resistor values is conducted using the following relationship: ##EQU5## wherein K is the desired gain of said amplifier, R 1 is said first value, and R 2 is said second value.
Claim 18
Dependent Claim
123 words
An electrical interface module for a thermal imaging system focal plane array (FPA), comprising: a digital processor for generating timing and logic signals of said FPA; a communication controller for receiving and storing timing data and bias adjustment commands of said FPA, said controller evaluating said timing data with the results provided to said processor; a memory for storing instructions which control the operation of said processor; and a video buffer having output capacitance cancellation, said buffer receiving an analog signal generated by said FPA and producing a standardized output, said buffer including an amplifier having a gain greater than unity for receiving said analog signal and positive feedback means for reducing power requirements and providing an increased pixel rate for said system.
Claim 19
Dependent Claim
123 words
An electrical interface module for a thermal imaging system focal plane array (FPA), comprising: a digital processor for generating timing and logic signals of said FPA; a communication controller for receiving and storing timing data and bias adjustment commands of said FPA, said controller evaluating said timing data with the results provided to said processor; a memory for storing instructions which control the operation of said processor; and a video buffer having output capacitance cancellation, said buffer receiving an analog signal generated by said FPA and producing a standardized output, said buffer including an amplifier having a gain greater than unity for receiving said analog signal and positive feedback means for reducing power requirements and providing an increased pixel rate for said system.
Claim 20
Dependent Claim
16 words
The electrical interface module of claim 16 wherein said positive feedback means is a feedback capacitor.
Claim 21
Dependent Claim
44 words
The electrical interface module of claim 17 wherein the value of said capacitor is selected using the following relationship: ##EQU6## wherein C 1 is said capacitor, K is the gain of said amplifier, and C s is the equivalent output capacitance of said FPA.
Claim 22
Dependent Claim
18 words
The electrical interface module of claim 16 wherein said FPA includes a plurality of photoelectrically responsive detector elements.
Claim 23
Dependent Claim
23 words
The electrical interface module of claim 16 wherein said analog signal is proportional to the flux of infrared light received by said FPA.
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) | 2001-10-12 | 2002-04-13 | 2002-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-12 | 2006-04-13 | 2006-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-12 | 2010-04-13 | 2010-10-13 | $7700.00 | Window Closed / Lapsed |