US4556910A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image sensing device having on-chip fixed-pattern noise reducing circuit
Assignee: Fujifilm Holdings Corp
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Filing: 1984-01-05
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Granted: 1985-12-03
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Expires: 2004-01-05
Abstract
Abstract An image sensing device having an on-chip output signal extracting circuit employing low gain-bandwidth product amplifiers and a simple circuit design. The output signal from scanning a photosensor element array is applied to the inverting input of an operational amplifier, the noninverting input of which receives a reference potential. A feedback capacitor is connected between the output and inverting input of the operational amplifier, and a resetting FET is connected in parallel with the feedback capacitor. An inverted replica of switching transients which occur on the inverting input terminal of the amplifier is fed to that terminal via a second capacitor. The output of the operational amplifier is buffered and applied to the output terminal of the sensor chip.
Inventors
- 👤 Gil Tisue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:37
CPC Classifications
H; H04; H04N; H04N25/00; H04N25/60; H04N25/67
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
166 words
An image sensing device on a semiconductor chip comprising: a chip output terminal; an array of photosensing elements; means responsive to clocking signals for sequentially coupling outputs of said photosensing elements to an array output terminal, said array output terminal having fixed-pattern noise thereon due to switching transients and induced noise; means for removing said fixed-pattern noise by integration of the output on said array output terminal over a period corresponding to the period of said clocking signals; and buffer means, connected between said removing means and said chip output terminal means, for isolating said chip output terminal from said removing means and from said array output terminal, wherein said removing means comprises an operational amplifier integrator having an inverting input coupled to said array output terminal, a first capacitor coupled between an output of said operational amplifier and said inverting input, an FET transistor having a channel coupled in parallel with said first capacitor and a gate coupled to a source of a reset signal.
Claim 2
Dependent Claim
166 words
An image sensing device on a semiconductor chip comprising: a chip output terminal; an array of photosensing elements; means responsive to clocking signals for sequentially coupling outputs of said photosensing elements to an array output terminal, said array output terminal having fixed-pattern noise thereon due to switching transients and induced noise; means for removing said fixed-pattern noise by integration of the output on said array output terminal over a period corresponding to the period of said clocking signals; and buffer means, connected between said removing means and said chip output terminal means, for isolating said chip output terminal from said removing means and from said array output terminal, wherein said removing means comprises an operational amplifier integrator having an inverting input coupled to said array output terminal, a first capacitor coupled between an output of said operational amplifier and said inverting input, an FET transistor having a channel coupled in parallel with said first capacitor and a gate coupled to a source of a reset signal.
Claim 3
Dependent Claim
44 words
The image sensing device of claim 1, further comprising a second capacitor coupled between said inverting input and a source of a signal having a waveshape similar to and a polarity opposite from a non-information-bearing component of a signal on said array output terminal.
Claim 4
Dependent Claim
21 words
The image sensing device of claim 1, wherein a noninverting input of said amplifier is coupled to a reference potential terminal.
Claim 5
Dependent Claim
25 words
The image sensing device of claim 1, wherein said buffer means is a buffer amplifier having a gain-bandwidth product of about 5 to 10 MHz.
Claim 6
Dependent Claim
42 words
The image sensing device of claim 2, wherein said source of said signal having a waveshape similar to and a polarity opposite from a non-information-bearing component of said signal on said array output terminal comprises a source of said reset signal inverted.
Claim 7
Dependent Claim
54 words
The image sensing device of claim 2, wherein said source of said signal having a waveshape similar to and a polarity opposite from a non-information-bearing component of said signal on said array output terminal comprises a resistive summing network receiving as inputs a source of said reset signal inverted and said clocking signals inverted.
References Cited (Backward Citations)
US4011442A
Cited
US4335406A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-02 | 1989-06-03 | 1989-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-02 | 1993-06-03 | 1993-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-02 | 1997-06-03 | 1997-12-03 | $7700.00 | Window Closed / Lapsed |