US7129975B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Addressable imager with real time defect detection and substitution
Assignee: RPX Corp
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Filing: 2002-01-10
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Granted: 2006-10-31
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Expires: 2022-01-10
Abstract
Abstract A video imaging system includes an imaging array having a plurality of picture elements (pixels) formed in a substrate. An analog to digital converter formed in the substrate converts signals from the pixels into digital pixel signals. A defect detection circuit formed in said substrate provides a defective pixel output signal indicating, as the digital pixel signal corresponding to the pixels is processed, if any one pixel of the plurality of pixels in the imaging array is defective. The video imaging system includes a defect substitution circuit, also formed in the substrate, that substitutes a corrected pixel for any defective pixel. The video imaging system is responsive to a gain control signal to adjusts the pixels in magnitude. The gain control signal is applied to the first circuit to control the analysis of the pixel to determine if it is defective.
Inventors
- 👤 Peter Alan Levine
- 👤 Nathaniel Joseph McCaffrey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:38
CPC Classifications
H; H04; H04N; H04N25/00; H04N25/60; H04N25/67; H04N25/68
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
171 words
A video imaging system comprising: a substrate of a semiconductor material; an imaging array formed in said substrate and having a plurality of picture elements (pixels) each pixel being adapted to receive light and convert the light to an electrical signal, said imaging array having an output port for providing the electrical signals from the pixels representing an active video image; a first circuit formed in said substrate and connected to receive the pixel signals and for analyzing the pixel signals to provide a defective pixel output signal indicating if any one pixel of the plurality of pixels in the imaging array is defective, as the pixel signal corresponding to the one pixel is processed by the first circuit, wherein said first circuit includes a filter that is responsive to a plurality of pixel values adjacent to the one pixel to provide an output signal, and circuitry including a comparator which compares the one pixel and to the output signal of the filter to determine if the one pixel is defective.
Claim 2
Dependent Claim
171 words
A video imaging system comprising: a substrate of a semiconductor material; an imaging array formed in said substrate and having a plurality of picture elements (pixels) each pixel being adapted to receive light and convert the light to an electrical signal, said imaging array having an output port for providing the electrical signals from the pixels representing an active video image; a first circuit formed in said substrate and connected to receive the pixel signals and for analyzing the pixel signals to provide a defective pixel output signal indicating if any one pixel of the plurality of pixels in the imaging array is defective, as the pixel signal corresponding to the one pixel is processed by the first circuit, wherein said first circuit includes a filter that is responsive to a plurality of pixel values adjacent to the one pixel to provide an output signal, and circuitry including a comparator which compares the one pixel and to the output signal of the filter to determine if the one pixel is defective.
Claim 3
Dependent Claim
57 words
A video imaging system in accordance with claim 1 , wherein the comparator further includes hysteresis circuitry that establishes a range of values including a value of the output signal of the filter and indicates that the one pixel is defective only when the one pixel has a value that is outside of the range of values.
Claim 4
Dependent Claim
49 words
A video imaging system in accordance with claim 2 further comprising a gain control circuit, formed in said substrate, the gain control circuit providing a camera pixel gain control output signal, wherein the hysteresis circuitry is responsive to the gain control output signal for establishing the range of values.
Claim 5
Dependent Claim
46 words
A video imaging system in accordance with claim 1 wherein: the imager further includes optics for focusing an image onto the imaging array, the optics having a modulation transfer function (MTF); and the filter has a frequency response characteristic that approximates the MTF of the optics.
Claim 6
Dependent Claim
30 words
A video imaging system in accordance with claim 1 , wherein the filter is an averaging filter that averages the plurality of adjacent pixel values to produce the output signal.
Claim 7
Dependent Claim
57 words
A video imaging system in accordance with claim 1 further comprising a second circuit, formed in said substrate, coupled to receive the defective pixel output signal, the one pixel and a corrected version of the one pixel, the second circuit providing the corrected pixel when the defective pixel output signal indicates that the one pixel is defective.
Claim 8
Dependent Claim
33 words
A video imaging system in accordance with claim 6 , wherein the second circuit further comprises a histogramming circuit, which generates the corrected pixel from the pixel signals provided by the imaging array.
Claim 9
Dependent Claim
32 words
A video imaging system in accordance with claim 6 , wherein the second circuit is coupled to the first circuit to receive the output signal of the filter as the corrected pixel.
Claim 10
Dependent Claim
33 words
An video imaging system in accordance with claim 6 in which the imaging array is a CMOS imager and the first and second circuits are CMOS circuits formed concurrently with the CMOS imager.
Claim 11
Independent Claim
130 words
A method for processing video signals representing at least one video image, each video image including a plurality of picture element (pixel) signals, the method comprising the steps of: analyzing the pixel signals to provide a defective pixel output signal indicating if any one pixel of the plurality of pixels in the at least one video image is defective, including the steps of: filtering a plurality of pixel values adjacent to the one pixel in the at least one video image to provide an output signal; processing the output signal to establish a range of values including the output signal; and comparing the one pixel to the range of values to provide a defective pixel output signal if the one pixel has a value outside of the range of values.
Claim 12
Independent Claim
130 words
A method for processing video signals representing at least one video image, each video image including a plurality of picture element (pixel) signals, the method comprising the steps of: analyzing the pixel signals to provide a defective pixel output signal indicating if any one pixel of the plurality of pixels in the at least one video image is defective, including the steps of: filtering a plurality of pixel values adjacent to the one pixel in the at least one video image to provide an output signal; processing the output signal to establish a range of values including the output signal; and comparing the one pixel to the range of values to provide a defective pixel output signal if the one pixel has a value outside of the range of values.
Claim 13
Dependent Claim
40 words
A method for processing video signals in accordance with claim 10 further comprising the steps of: modifying the pixel signals in magnitude responsive to a gain control signal; and modifying the range of values responsive to the gain control signal.
Claim 14
Dependent Claim
66 words
A method for processing video signals in accordance with claim 10 , wherein the video images are formed in accordance with a modulation transfer function (MTF); and the step of filtering the plurality of pixel values adjacent to the one pixel value includes the step of filtering the plurality of pixel values with a frequency response characteristic that approximates the MTF to produce the output signal.
Claim 15
Dependent Claim
58 words
A method for processing video signals in accordance with claim 10 , wherein the video images are formed in accordance with a modulation transfer function (MTF); and the step of filtering the plurality of pixel values adjacent to the one pixel value includes the step of averaging the plurality of adjacent pixel values to produce the output signal.
Claim 16
Dependent Claim
42 words
A method for processing video signals in accordance with claim 10 , further including the step of replacing the one pixel with a corrected version of the one pixel when the defective pixel output signal indicates that the one pixel is defective.
Claim 17
Dependent Claim
52 words
A method for processing video signals in accordance with claim 14 , further includes the step of generating a histogram of the pixels in at least a portion of the video image including the one pixel and selecting a most frequently occurring pixel to generate the corrected version of the one pixel.
Claim 18
Dependent Claim
27 words
A method for processing video signals in accordance with claim 14 , further includes the step of filtering the plurality of pixels to generate the corrected pixel.
Claim 19
Dependent Claim
29 words
A method for processing video signals in accordance with claim 14 , further including the step of applying the output signal of the filtering step as the corrected pixel.
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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) | 2009-10-30 | 2010-05-01 | 2010-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2013-10-30 | 2014-05-01 | 2014-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2017-10-30 | 2018-05-01 | 2018-10-31 | $7700.00 | Window Closed / Lapsed |