Patent US4677490A successfully refreshed from Google Patents.
US4677490A
Expired / Lapsed
US
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CCD imager output signal processing using drain output signal and wide-band sampled detected floating-element output signal
Assignee: RCA Corp
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Filing: 1985-09-13
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Granted: 1987-06-30
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Expires: 2005-09-13
Abstract
Abstract First and second output signals are taken from a floating element in a CCD charge transfer channel and from the terminal drain diffusion of that CCD charge transfer channel. The floating element is part of an electrometer, and the electrometer response is wide-band sampled at the CCD charge transfer channel clocking rate. Current flow through the terminal drain diffusion is sensed by the input circuit of a low l/f noise transresistance amplifier. Continuous-frequency-spectrum low-noise output signal is generated from the low-frequency components of the transresistance amplifier response and from the high-frequency components of the processed second output signal. Subsequent filtering removes unwanted clock and aliased frequency components.
Inventors
- 👤 Peter A. Levine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:25
CPC Classifications
H; H04; H04N; H04N25/00; H04N25/60; H04N25/62; H04N25/621; H04N25/622
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
175 words
In combination with a solid-state imager having an output charge-coupled device charge transfer channel clocked at a prescribed clock rate, having a floating element electrometer for sensing charge at a point in said charge transfer channel to supply a first signal at a first electrical output, and having a terminal drain at the end of said charge transfer channel for supplying a further signal at a second electrical output, circuitry for generating an output video signal responsive to the signals at said first and second electrical outputs comprising: means for deriving the high-frequency portion of said output video signal, said deriving means including means coupled to said first electrical output for providing wide-band multiple sampling of the video information portion of said first signal, which wide-band sampling is associated with the generation of undesirable low-frequency-fixed pattern shading; means for deriving the low-frequency portion of said output video signal from said further signal at said second electrical output; and means for combining the low-frequency and high-frequency portions of said output video signal into a continuous-frequency-spectrum signal.
Claim 2
Dependent Claim
175 words
In combination with a solid-state imager having an output charge-coupled device charge transfer channel clocked at a prescribed clock rate, having a floating element electrometer for sensing charge at a point in said charge transfer channel to supply a first signal at a first electrical output, and having a terminal drain at the end of said charge transfer channel for supplying a further signal at a second electrical output, circuitry for generating an output video signal responsive to the signals at said first and second electrical outputs comprising: means for deriving the high-frequency portion of said output video signal, said deriving means including means coupled to said first electrical output for providing wide-band multiple sampling of the video information portion of said first signal, which wide-band sampling is associated with the generation of undesirable low-frequency-fixed pattern shading; means for deriving the low-frequency portion of said output video signal from said further signal at said second electrical output; and means for combining the low-frequency and high-frequency portions of said output video signal into a continuous-frequency-spectrum signal.
Claim 3
Dependent Claim
239 words
In combination with a solid-state imager having an output charge-coupled device charge transfer channel clocked at a prescribed clock rate, having a floating element electrometer for sensing charge at a point in said charge transfer channel to supply a first electrical output signal, and having a terminal drain at the end of said charge transfer channel for supplying a second output signal, circuitry for generating an output video signal responsive to said first and second electrical signals comprising: means for deriving the high-frequency portion of said output video signal from said first electrical output signal after wide-band sampling thereof, which wide-band sampling is associated with the generation of undesirable low-frequency-fixed pattern shading; means for deriving the low-frequency portion of said output video signal from said second electrical output signal; means for combining the low-frequency and high-frequency portions of said output video signal into a continuous-frequency-spectrum signal; and said means for deriving the high-frequency portion of said output signal includes: a low-frequency-suppresion filter, with an input connection receptive of said first electrical output signal from said solid-state imager, and with an output connection; and a synchronous detector having an input connection from the output connection of said low-frequency-suppression filter, performing said wide-band sampling at a harmonic of said prescribed clock rate, and having an output connection; and a filter separating the high-frequency portion of response at the output connection of said synchronous detector, for application to said means for combining.
Claim 4
Dependent Claim
239 words
In combination with a solid-state imager having an output charge-coupled device charge transfer channel clocked at a prescribed clock rate, having a floating element electrometer for sensing charge at a point in said charge transfer channel to supply a first electrical output signal, and having a terminal drain at the end of said charge transfer channel for supplying a second output signal, circuitry for generating an output video signal responsive to said first and second electrical signals comprising: means for deriving the high-frequency portion of said output video signal from said first electrical output signal after wide-band sampling thereof, which wide-band sampling is associated with the generation of undesirable low-frequency-fixed pattern shading; means for deriving the low-frequency portion of said output video signal from said second electrical output signal; means for combining the low-frequency and high-frequency portions of said output video signal into a continuous-frequency-spectrum signal; and said means for deriving the high-frequency portion of said output signal includes: a low-frequency-suppresion filter, with an input connection receptive of said first electrical output signal from said solid-state imager, and with an output connection; and a synchronous detector having an input connection from the output connection of said low-frequency-suppression filter, performing said wide-band sampling at a harmonic of said prescribed clock rate, and having an output connection; and a filter separating the high-frequency portion of response at the output connection of said synchronous detector, for application to said means for combining.
Claim 5
Dependent Claim
198 words
In combination with a solid-state imager having an output charge-coupled device charge transfer channel clocked at a prescribed clock rate, having a floating element electrometer for sensing charge at a point in said charge transfer channel to supply a first electrical output signal, and having a terminal drain at the end of said charge transfer channel for supplying a second output signal, circuitry for generating an output video signal responsive to said first and second electrical signals comprising: means for deriving the high-frequency portion of said output video signal from said first electrical output signal after wide-band sampling thereof, which wide-band sampling is associated with the generation of undesirable low-frequency-fixed pattern shading; means for deriving the low-frequency portion of said output video signal from said second electrical output signal; means for combining the low-frequency and high-frequency portions of said output video signal into a continuous-frequency-spectrum signal; and said means for deriving the high-frequency portion of said output signal includes: correlated double sampling apparatus for wide-band sampling said first electrical output signal from said solid-state imager; and a filter separating the high-frequency portion of the correlated double sampled first electrical output signal, for application to said means for combining.
Claim 6
Dependent Claim
198 words
In combination with a solid-state imager having an output charge-coupled device charge transfer channel clocked at a prescribed clock rate, having a floating element electrometer for sensing charge at a point in said charge transfer channel to supply a first electrical output signal, and having a terminal drain at the end of said charge transfer channel for supplying a second output signal, circuitry for generating an output video signal responsive to said first and second electrical signals comprising: means for deriving the high-frequency portion of said output video signal from said first electrical output signal after wide-band sampling thereof, which wide-band sampling is associated with the generation of undesirable low-frequency-fixed pattern shading; means for deriving the low-frequency portion of said output video signal from said second electrical output signal; means for combining the low-frequency and high-frequency portions of said output video signal into a continuous-frequency-spectrum signal; and said means for deriving the high-frequency portion of said output signal includes: correlated double sampling apparatus for wide-band sampling said first electrical output signal from said solid-state imager; and a filter separating the high-frequency portion of the correlated double sampled first electrical output signal, for application to said means for combining.
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) | 1990-06-29 | 1990-12-29 | 1991-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-29 | 1994-12-29 | 1995-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-29 | 1998-12-29 | 1999-06-30 | $7700.00 | Window Closed / Lapsed |