Patent US5995145A successfully refreshed from Google Patents.
US5995145A
Expired / Lapsed
US
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Image capture apparatus for selectively causing a stepped reduction in video image signal values
Assignee: Sony Broadcast and Communications Ltd
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Filing: 1993-12-15
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Granted: 1999-11-30
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Expires: 2013-12-15
Abstract
Abstract An image capture apparatus (eg. a video camera) for producing video image signals includes an image sensor for producing image signals having signal values representative of radiation intensity incident on respective positions of the sensor. The apparatus is able to identify an area of the sensor at which the incident intensity exceeds a predetermined intensity and to cause a stepped reduction in the image signal values corresponding to said area. The apparatus enables a range of intensity levels above a predetermined maximum to be translated or shifted to within a range which can be accommodated, for example by a broadcast television system, in a manner equivalent to applying a negative pedestal to that range of intensity levels. Preferably, for detecting an area of the sensor at which the incident intensity exceeds a predetermined intensity, a sense array additional to the image sensor is provided for producing sample signals representative of the radiation incident on the sensor at corresponding image positions. Various specific examples of the apparatus are described.
Inventors
- 👤 Nicholas Alfred William Viliesid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:08
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/70; H04N23/75; H04N23/73; H04N23/76; H04N25/00; H04N25/50; H04N25/57; H04N25/571; H04N25/70; H04N25/71; H04N25/75; H04N25/76; H04N25/78
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
102 words
Image capture apparatus for producing video image signals, comprising: image sensor means for producing video image signals having voltage levels representative of radiation intensities incident on respective areas of said image sensor means; means for identifying those respective areas of said image sensor means at which the incident radiation intensity exceeds a predetermined intensity and for producing a control signal representative thereof; and means responsive to said control signal for selectively causing a reduction in the voltage levels of said video image signals corresponding to said respective areas, which reduction is equivalent to applying a negative offset to said video image signals.
Claim 2
Dependent Claim
102 words
Image capture apparatus for producing video image signals, comprising: image sensor means for producing video image signals having voltage levels representative of radiation intensities incident on respective areas of said image sensor means; means for identifying those respective areas of said image sensor means at which the incident radiation intensity exceeds a predetermined intensity and for producing a control signal representative thereof; and means responsive to said control signal for selectively causing a reduction in the voltage levels of said video image signals corresponding to said respective areas, which reduction is equivalent to applying a negative offset to said video image signals.
Claim 3
Dependent Claim
67 words
An image capture apparatus as claimed in claim 1 wherein the means for identifying those respective areas of the image sensor means at which the incident radiation intensity exceeds a predetermined intensity includes threshold detection means responsive to the video image signals output by the image sensor means for detecting voltage levels exceeding a predetermined level as indicative of an incident radiation intensity exceeding the predetermined intensity.
Claim 4
Dependent Claim
49 words
An image capture apparatus as claimed in claim 2 comprising attenuation means responsive to the threshold detection means selectively to reduce a voltage level representative of an incident radiation intensity exceeding the predetermined intensity to produce a reduced voltage level representative of a radiation intensity below the predetermined intensity.
Claim 5
Dependent Claim
35 words
An image capture apparatus as claimed in claim 3 wherein the attenuation means is operative to pass unaltered a video image signal having a voltage level representative of a radiation intensity below the predetermined intensity.
Claim 6
Dependent Claim
75 words
An image capture apparatus as claimed in claim 3 wherein the image sensor means is a scanned sensor producing signals for a 2-D array of pixels, the image sensor means comprising a plurality of output lines for respective pixel positions along a scan line, and wherein the threshold detection means comprises a plurality of threshold detectors associated with respective output lines and the attenuation means comprises a plurality of attenuators associated with respective threshold detectors.
Claim 7
Dependent Claim
26 words
An image capture apparatus as claimed in claim 3 comprising storage means connected to the output of the attenuation means for storing the processed image signals.
Claim 8
Dependent Claim
74 words
An image capture apparatus as claimed in claim 2 wherein the image sensor means comprises an array of sense elements having respective image integration times of which are controllable, the image capture apparatus comprising control means responsive to the threshold detection means indicating an incident radiation intensity exceeding the predetermined intensity selectively to reduce the integration time of the respective sense element or elements at which the incident radiation intensity exceeds the predetermined intensity.
Claim 9
Dependent Claim
116 words
An image capture apparatus as claimed in claim 2 comprising a programmable optical filter interposed in the optical path preceding the image sensor means, and control means for causing the programmable optical filter to be set to a selected transmission coefficient during a calibration period when the image capture apparatus is not outputting a video image signal, the control means being responsive to signals output by the threshold detection means during a calibration time to reduce, for a subsequent active output period during which a video image signal is output, the transmission coefficient of the programmable optical filter at locations corresponding to areas of the sensed image at which the radiation intensity exceeds the predetermined intensity.
Claim 10
Dependent Claim
28 words
An image capture apparatus as claimed in claim 8 wherein the programmable optical filter is located between the image sensor means and optical elements in the optical path.
Claim 11
Dependent Claim
21 words
An image capture apparatus as claimed in claim 8 wherein the programmable optical filter comprises an array of liquid crystal elements.
Claim 12
Dependent Claim
62 words
The image capture apparatus as claimed in claim 1 comprising sense array means responsive to said radiation for producing sample signal values representative of the radiation intensities incident on the respective areas of the image sensor means, wherein the means for identifying comprises threshold detection means responsive to said sample signal values to indicate an incident radiation intensity exceeding the predetermined intensity.
Claim 13
Dependent Claim
38 words
The image capture apparatus as claimed in claim 11 comprising beam splitter means in an optical path preceding the image sensor means for diverting from said optical path part of the incident radiation onto the sense array means.
Claim 14
Dependent Claim
49 words
An image capture apparatus as claimed in claim 11 comprising attenuation means responsive to the threshold detection means selectively to reduce a voltage level representative of an incident radiation intensity exceeding the predetermined intensity to produce a reduced voltage level representative of a radiation intensity below the predetermined intensity.
Claim 15
Dependent Claim
35 words
An image capture apparatus as claimed in claim 13 wherein the attenuation means is operative to pass unaltered a video image signal having a voltage level representative of a radiation intensity below the predetermined intensity.
Claim 16
Dependent Claim
75 words
An image capture apparatus as claimed in claim 13 wherein the image sensor means is a scanned sensor producing signals for a 2-D array of pixels, the image sensor means comprising a plurality of output lines for respective pixel positions along a scan line, and wherein the threshold detection means comprises a plurality of threshold detectors associated with respective output lines and the attenuation means comprises a plurality of attenuators associated with respective threshold detectors.
Claim 17
Dependent Claim
26 words
An image capture apparatus as claimed in claim 11 comprising storage means connected to the output of the attenuation means for storing the processed image signals.
Claim 18
Dependent Claim
74 words
An image capture apparatus as claimed in claim 11 wherein the image sensor means comprises an array of sense elements having respective image integration times of which are controllable, the image capture apparatus comprising control means responsive to the threshold detection means indicating an incident radiation intensity exceeding the predetermined intensity selectivity to reduce the integration time of the respective sense element or elements at which the incident radiation intensity exceeds the predetermined intensity.
Claim 19
Dependent Claim
83 words
Image capture apparatus as in claim 11, further comprising a programmable optical filter having an array of optical filter elements with programmable transmission coefficients in an optical path preceding the image sensor means, and control means responsive to the threshold detection means indicating an incident radiation intensity exceeding the predetermined intensity selectively to reduce the transmission coefficient of the programmable optical filter at locations corresponding to the area of the image sensor means at which the incident radiation intensity exceeds the predetermined intensity.
Claim 20
Dependent Claim
26 words
Image capture apparatus as in claim 18, wherein the programmable optical filter is located between the image sensor means and optical elements in the optical path.
Claim 21
Dependent Claim
19 words
Image capture apparatus as in claim 18, wherein the programmable optical filter includes an array of liquid crystal elements.
Claim 22
Dependent Claim
22 words
The image capture apparatus as claimed in claim 1 wherein the image sensor means comprises an array of charge coupled device elements.
Claim 23
Dependent Claim
23 words
The image capture apparatus as claimed in claim 1 wherein said respective areas correspond to a pixel resolution of the image sensor means.
Claim 24
Dependent Claim
18 words
The image capture apparatus as claimed in claim 1 wherein the image capture apparatus is a video camera.
Claim 25
Dependent Claim
46 words
Image capture apparatus as in claim 1, in which said means responsive to said control signal for selectively causing the reduction in the voltage levels of said video image signals includes a programmable optical filter through which said radiation is incident on said image sensor means.
Claim 26
Dependent Claim
26 words
A programmable optical filter for use in an image capture apparatus as in claim 1, comprising an array of optical filter elements with controllable transmission coefficients.
Claim 27
Dependent Claim
16 words
The programmable optical filter as in claim 25, further including an array of liquid crystal elements.
Claim 28
Dependent Claim
66 words
Image capture apparatus as in claim 1, in which said means responsive to said control signal for selectively causing the reduction in the voltage levels of said video image signals includes a programmable attenuator coupled to receive said video image signals and responsive to said control signal for selectively causing a reduction in the voltage levels of said video image signals corresponding to said respective areas.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2002-11-29 | 2003-05-31 | 2003-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-11-29 | 2007-05-31 | 2007-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-11-29 | 2011-05-31 | 2011-11-30 | $7700.00 | Window Closed / Lapsed |