Patent US6803958B1 successfully refreshed from Google Patents.
US6803958B1
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US
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Apparatus and method for eliminating artifacts in active pixel sensor (APS) imagers
Assignee: Micron Technology Inc
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Filing: 2000-03-09
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Granted: 2004-10-12
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Expires: 2020-03-09
Abstract
Abstract An active pixel sensor (APS) that includes circuitry to eliminate artifacts in digital images. The APS includes a comparator for comparing a signal level from a pixel to an adjusted saturation voltage to determine if the pixel is saturated. If the pixel is saturated, the signal output from the pixel is replaced with an analog voltage having a maximum value corresponding to a brightest pixel in the image.
Inventors
- 👤 Yibing (Michelle) Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:08
CPC Classifications
H; H04; H04N; H04N25/00; H04N25/60; H04N25/62; H04N25/627; H04N23/00; H04N23/70; H04N23/76; H04N25/70; H04N25/76; H04N25/78
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
97 words
An active pixel sensor comprising: at least one pixel comprising a photodetector that outputs an output level indicative of incoming light; a storage element, electrically connected to the photodetector, operating to store said output level during a photodetector readout operation; a comparison element electrically connected to said storage element operating to compare said output level and an adjusted saturation voltage; and an output selector electrically connected to said comparison element, operating to output an adjusted maximum voltage during pixel readout operation in response to the comparison element determining that said adjusted saturation voltage exceeds said output level.
Claim 2
Dependent Claim
97 words
An active pixel sensor comprising: at least one pixel comprising a photodetector that outputs an output level indicative of incoming light; a storage element, electrically connected to the photodetector, operating to store said output level during a photodetector readout operation; a comparison element electrically connected to said storage element operating to compare said output level and an adjusted saturation voltage; and an output selector electrically connected to said comparison element, operating to output an adjusted maximum voltage during pixel readout operation in response to the comparison element determining that said adjusted saturation voltage exceeds said output level.
Claim 3
Dependent Claim
27 words
The active pixel sensor of claim 1 further comprising an adjusted saturation voltage source electrically connected to said comparison element operating to provide said adjusted saturation voltage.
Claim 4
Dependent Claim
27 words
The active pixel sensor of claim 1 further comprising an adjusted maximum voltage source electrically connected to said output selector operating to provide said adjusted maximum voltage.
Claim 5
Dependent Claim
24 words
The active pixel sensor of claim 1 wherein the photodetector is selected from the group comprising a photodiode, a photogate, and a pinned photodiode.
Claim 6
Dependent Claim
22 words
The active pixel sensor of claim 1 wherein the adjusted saturation voltage is greater than a voltage at which the photodetector saturates.
Claim 7
Dependent Claim
14 words
The active pixel sensor of claim 1 wherein the comparison element is a comparator.
Claim 8
Dependent Claim
22 words
The active pixel sensor of claim 1 wherein the adjusted maximum voltage is an operating voltage of the at least one pixel.
Claim 9
Dependent Claim
31 words
The active pixel sensor of claim 1 further comprising an analog-to-digital converter electrically connected to the output selector and operating to convert the adjusted maximum voltage to a maximum digital value.
Claim 10
Dependent Claim
20 words
The active pixel sensor of claim 8 wherein the maximum digital value is an 8-bit word having the value “11111111”.
Claim 11
Dependent Claim
33 words
The active pixel sensor of claim 1 further comprising a differencing element electrically connected to the storage element and operating to calculate a difference voltage from said output level and a reset level.
Claim 12
Dependent Claim
37 words
The active pixel sensor of claim 10 wherein the output selector operates to output said difference voltage during the pixel readout operation in response to the comparator determining that the output level exceeds the adjusted saturation voltage.
Claim 13
Independent Claim
95 words
A method comprising: storing an output level indicative of incoming light output from a photodetector during a photodetector readout operation; comparing said output level to an adjusted saturation voltage; outputting an adjusted maximum voltage during a pixel readout operation in response to said adjusted saturation voltage exceeding said output level; storing a reset level from the photodetector during the photodetector readout operation; calculating a difference voltage from said output level and said reset level; and outputting said difference voltage during the pixel readout operation in response to said output level exceeding said adjusted saturation voltage.
Claim 14
Independent Claim
95 words
A method comprising: storing an output level indicative of incoming light output from a photodetector during a photodetector readout operation; comparing said output level to an adjusted saturation voltage; outputting an adjusted maximum voltage during a pixel readout operation in response to said adjusted saturation voltage exceeding said output level; storing a reset level from the photodetector during the photodetector readout operation; calculating a difference voltage from said output level and said reset level; and outputting said difference voltage during the pixel readout operation in response to said output level exceeding said adjusted saturation voltage.
Claim 15
Dependent Claim
20 words
The method of claim 12 wherein said adjusted saturation voltage is greater than a voltage at which the photodetector saturates.
Claim 16
Dependent Claim
17 words
The method of claim 12 further comprising converting said adjusted maximum voltage to a maximum digital value.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2007-10-12 | 2008-04-12 | 2008-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-10-12 | 2012-04-12 | 2012-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-10-12 | 2016-04-12 | 2016-10-12 | $7700.00 | Window Closed / Lapsed |