Patent US3683108A successfully refreshed from Google Patents.
US3683108A
Expired / Lapsed
US
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Television camera tube residual charge removal
Assignee: Individual
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Filing: 1970-10-30
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Granted: 1972-08-08
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Expires: 1990-10-30
Abstract
Abstract This invention concerns the reduction in the time taken to erase the residual charge pattern from a television camera tube target. The invention is applicable to television camera tubes having a photosensitive layer of fast internal time constant which is defined in the specification. The invention is performed by increasing the scanning rate of the electron beam during the erase scan. In this way more than one erase scan can be performed in the time normally occupied by a single frame scan of the camera target. Either frame scanning rate or line scanning rate or both can be increased. If the line scanning rate is increased it is also found necessary to increase the beam current and in some circumstances increased spot size during erase intervals has also been found to be advantageous. The invention also provides for gating the video output from the camera tube during each erase interval.
Inventors
- 👤 Leon Andre Pieters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:02
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/40
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
114 words
In a method of image analysis employing a television camera tube having a target with a fast internal time constant photosensitive layer, wherein an image to be scanned is flashed on to the photosensitive layer to form a charge pattern thereon corresponding to the image, the charge pattern is read during one read-out scan of a scanning electron beam and any residual charge pattern in the photosensitive layer corresponding to a preceeding image is removed by a plurality of erase scans by the electron beam prior to the next read scan, the improvement comprising, increasing the rate of scanning of said electron beam performed per unit time for the duration of the erAse interval.
Claim 2
Dependent Claim
114 words
In a method of image analysis employing a television camera tube having a target with a fast internal time constant photosensitive layer, wherein an image to be scanned is flashed on to the photosensitive layer to form a charge pattern thereon corresponding to the image, the charge pattern is read during one read-out scan of a scanning electron beam and any residual charge pattern in the photosensitive layer corresponding to a preceeding image is removed by a plurality of erase scans by the electron beam prior to the next read scan, the improvement comprising, increasing the rate of scanning of said electron beam performed per unit time for the duration of the erAse interval.
Claim 3
Dependent Claim
26 words
The method as set forth in claim 1 further comprising the step of blocking the video signal output from the camera tube during the erase interval.
Claim 4
Dependent Claim
44 words
The method as set forth in claim 2 wherein said step of increasing the rate of scanning comprises increasing the frame scan rate and wherein the spot size on the target is increased simultaneously with increasing said frame scan rate during the erase interval.
Claim 5
Dependent Claim
22 words
The method as set forth in claim 3 wherein the spot size is increased by altering the focusing of the electron beam.
Claim 6
Dependent Claim
65 words
The method as set forth in claim 1 wherein said step of increasing the rate of scanning comprises increasing the number of frame scans performed per unit time and wherein the number of line scans performed per unit time and the current of said electron beam are simultaneously increased with increasing the number of frame scans performed per unit of time during the erase interval.
Claim 7
Dependent Claim
26 words
The method as set forth in claim 5 further comprising the step of blocking the video signal output from the camera tube during the erase interval.
Claim 8
Dependent Claim
20 words
The method as set forth in claim 5 comprising the step of increasing the spot size during the erase interval.
Claim 9
Dependent Claim
150 words
Apparatus for producing a video signal for an image analysis system corresponding to an image which is flashed onto the photosensitive layer of a television camera tube and which is converted into a video signal during a read scan and in which the residual charge pattern is reduced to an acceptable layer during subsequent erase scans, comprising in combination: a television camera tube having a fast internal time constant photosensitive layer, means for generating line scan pulses, means for generating frame scan pulses, a read-erase control unit arranged to generate switching signals for controlling the frame scan generator to increase the frequency of the frame scan pulses during the erase intervals to be greater than the frequency of the frame scan pulses during the read interval, and a master timing generator for controlling and synchronizing the line scan pulse generator, the frame scan pulse generator and the read-erase control unit.
Claim 10
Dependent Claim
150 words
Apparatus for producing a video signal for an image analysis system corresponding to an image which is flashed onto the photosensitive layer of a television camera tube and which is converted into a video signal during a read scan and in which the residual charge pattern is reduced to an acceptable layer during subsequent erase scans, comprising in combination: a television camera tube having a fast internal time constant photosensitive layer, means for generating line scan pulses, means for generating frame scan pulses, a read-erase control unit arranged to generate switching signals for controlling the frame scan generator to increase the frequency of the frame scan pulses during the erase intervals to be greater than the frequency of the frame scan pulses during the read interval, and a master timing generator for controlling and synchronizing the line scan pulse generator, the frame scan pulse generator and the read-erase control unit.
Claim 11
Dependent Claim
49 words
Apparatus as set forth in claim 8 comprising in combination therewith electrical or electronic gate means controlling the video signal output of the camera tube and responsive to signals from the read-erase control unit to block the passage of video signal from the camera tube during the erase interval.
Claim 12
Dependent Claim
30 words
Apparatus as set forth in claim 9 further comprising in combination therewith means to defocus the beam in the camera tube to thereby increase spot size during the erase interval.
Claim 13
Dependent Claim
51 words
Apparatus as set forth in claim 9 further comprising in combination therewith means to increase the frequency of the line scan pulses produced by the line scan generator and means to increase the beam current of the camera tube, each said means being responsive to signals from the read-erase control unit.
Claim 14
Dependent Claim
34 words
Apparatus as set forth in claim 11 further comprising in combination therewith means for controlling the focusing of the camera beam to defocus the beam and thereby increase spot size during the erase interval.
Claim 15
Dependent Claim
147 words
In a method of image analysis employing a television camera tube having a target with a fast internal time constant photosensitive layer wherein an image to be scanned is flashed on to the photosensitive layer to form a charge pattern thereon corresponding to the image, the charge pattern is read during one read-out scan of a scanning electron beam occurring during a read-out interval and any residual charge pattern in the photosensitive layer corresponding to a preceding image is removed by a plurality of erase scans by the electron beam prior to the next read scan, said erase scans occurring during an erase interval, the improvement comprising: increasing the rate of scanning of said electron beam performed per unit time during said erase interval so that it is greater than the rate of scanning durinG said read interval and correspondingly decreasing the duration of said erase interval.
Claim 16
Dependent Claim
147 words
In a method of image analysis employing a television camera tube having a target with a fast internal time constant photosensitive layer wherein an image to be scanned is flashed on to the photosensitive layer to form a charge pattern thereon corresponding to the image, the charge pattern is read during one read-out scan of a scanning electron beam occurring during a read-out interval and any residual charge pattern in the photosensitive layer corresponding to a preceding image is removed by a plurality of erase scans by the electron beam prior to the next read scan, said erase scans occurring during an erase interval, the improvement comprising: increasing the rate of scanning of said electron beam performed per unit time during said erase interval so that it is greater than the rate of scanning durinG said read interval and correspondingly decreasing the duration of said erase interval.
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) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |