US3558809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic dark current control system for pickup tubes employing a light inhibiting strip mounted on the pickup tube face plate
Assignee: Sony Corp
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Filing: 1968-07-30
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Granted: 1971-01-26
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Expires: 1988-07-30
Abstract
Abstract An automatic dark current control system for a pickup tube including an opaque region provided on the pickup tube face plate, means for detecting an output signal corresponding to the opaque region, and means for controlling a target voltage with the detected signal.
Inventors
- 👤 Takao Aoki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:34
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/40; H04N23/70; H04N23/749
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
77 words
An automatic dark current control system for pickup tubes comprising means for providing a light-transmission inhibiting region on a target of the pickup tube at one selected area, means for detecting the level of the portion of a video output signal produced by scanning the light-transmission inhibiting region, and means for controlling the target voltage with the detected portion of the video output signal produced by scanning the light-inhibiting region to hold the said level substantially constant.
Claim 2
Dependent Claim
77 words
An automatic dark current control system for pickup tubes comprising means for providing a light-transmission inhibiting region on a target of the pickup tube at one selected area, means for detecting the level of the portion of a video output signal produced by scanning the light-transmission inhibiting region, and means for controlling the target voltage with the detected portion of the video output signal produced by scanning the light-inhibiting region to hold the said level substantially constant.
Claim 3
Dependent Claim
44 words
2. An automatic dark current control system for pickup tubes as claimed in claim 1 including a deflection means of the pickup tube in which the detecting means includes a sampling circuit operated in synchronization with a deflection signal applied to the deflection means.
Claim 4
Dependent Claim
28 words
An automatic dark current control system for pickup tubes as claimed in claim 1 in which the light-transmission inhibiting region is scanned during an ineffective video signal period.
Claim 5
Dependent Claim
26 words
An automatic dark current control system for pickup tubes as claimed in claim 1 including a plurality of pickup tubes respectively for the different color images.
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) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |