US3764738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and arrangement for limiting the output signal amplitude of a video amplifier during fly-back highlight discharge
Assignee: Robert Bosch Fernsehanlagen GmbH
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Filing: 1973-02-15
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Granted: 1973-10-09
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Expires: 1993-02-15
Abstract
Abstract A method and apparatus for amplifying television picture signals. The amplified television picture signals from an amplifier are monitored by a circuit arrangement including a Zener diode. When the amplitude level of the amplified signals exceeds a predetermined value, the Zener diode becomes conductive and an auxiliary signal is generated. A normally high resistance semi-conductor arrangement is connected in parallel with the high resistance in the input circuit of the amplifier. The semiconductor arrangement is normally non-conductive, and in such cases, the effective load impedance at the input of the amplifier is substantially equal to the high resistance. When the auxiliary signals are applied to the semi-conductor arrangement, the latter becomes conductive to thereby provide a substantially lower resistance in the input circuit of the amplifier. In the latter case, the voltage levels developed at the input of the amplifier are limited, to thereby limit the amplitude of the amplified signals at the output of the amplifier.
Inventors
- 👤 H Zettl
- 👤 E Siegel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:52
CPC Classifications
H; H04; H04N; H04N23/00; H04N23/40; H04N23/70; H04N23/749; H04N23/76
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
136 words
In a television camera having a pick-up tube having a determined sensitivity and having a signal electrode for furnishing television picture signals, and amplifier means having an input connected to said signal electrode and an output for furnishing amplified television picture signals corresponding to said television picture signals, a method for limiting the amplitude of said amplified television picture signals to a predetermined maximum amplitude while maintaining said determined sensitivity of said pick-up tube, comprising, in combination, the steps of furnishing an auxiliary signal when said amplitude of said amplified television picture signals exceeds said predetermined maximum amplitude; and limiting the amplitude of said television picture signals at said signal electrode to an amplitude corresponding to said predetermined maximum amplitude in response to said auxiliary signal, while maintaining said sensitivity of said pick-up tube substantially constant.
Claim 2
Dependent Claim
136 words
In a television camera having a pick-up tube having a determined sensitivity and having a signal electrode for furnishing television picture signals, and amplifier means having an input connected to said signal electrode and an output for furnishing amplified television picture signals corresponding to said television picture signals, a method for limiting the amplitude of said amplified television picture signals to a predetermined maximum amplitude while maintaining said determined sensitivity of said pick-up tube, comprising, in combination, the steps of furnishing an auxiliary signal when said amplitude of said amplified television picture signals exceeds said predetermined maximum amplitude; and limiting the amplitude of said television picture signals at said signal electrode to an amplitude corresponding to said predetermined maximum amplitude in response to said auxiliary signal, while maintaining said sensitivity of said pick-up tube substantially constant.
Claim 3
Dependent Claim
42 words
A method as set forth in claim 1, wherein said step of creating an auxiliary signal comprises monitoring said amplified television picture signals and creating said auxiliary signal when the amplitude of said amplified television picture signals exceed said predetermined maximum amplitude.
Claim 4
Dependent Claim
65 words
A method as set forth in claim 2, wherein said television picture signals have retrace intervals; wherein said pick-up tube is operated with fly-back highlight discharge, whereby said television picture signals have signal peaks substantially exceeding said amplitude corresponding to said predetermined maximum amplitude during said retrace intervals; and wherein creating said auxiliary signal comprises creating said auxiliary signal in response to said signal peaks.
Claim 5
Dependent Claim
124 words
In a television camera, a signal limiting arrangement, comprising, in combination, a pick-up tube having a determined sensitivity and having a signal electrode for furnishing a television pick-up signal having retrace intervals; amplifier means having an input connected to said signal electrode and having an output for furnishing amplified television picture signals corresponding to said television picture signals; monitoring means connected to said amplifier means for furnishing an auxiliary signal when the amplitude of said amplified television picture signals exceeds a predetermined maximum amplitude; and regulation means connected to said monitoring means and said input of said amplifier means, for preventing an increase of amplitude of signals at said input in response to said auxiliary signal, independent of said sensitivity of said pick-up tube.
Claim 6
Dependent Claim
124 words
In a television camera, a signal limiting arrangement, comprising, in combination, a pick-up tube having a determined sensitivity and having a signal electrode for furnishing a television pick-up signal having retrace intervals; amplifier means having an input connected to said signal electrode and having an output for furnishing amplified television picture signals corresponding to said television picture signals; monitoring means connected to said amplifier means for furnishing an auxiliary signal when the amplitude of said amplified television picture signals exceeds a predetermined maximum amplitude; and regulation means connected to said monitoring means and said input of said amplifier means, for preventing an increase of amplitude of signals at said input in response to said auxiliary signal, independent of said sensitivity of said pick-up tube.
Claim 7
Dependent Claim
28 words
An arrangement as set forth in claim 4, wherein said monitoring means are connected to said output of said amplifier means, for monitoring said amplified television picture signals.
Claim 8
Dependent Claim
37 words
An arrangement as set forth in claim 5, further comprising a source of D.C. voltage for providing an operating voltage to said signal electrode; and resistance means connecting said source of D.C. voltage to said signal electrode.
Claim 9
Dependent Claim
50 words
An arrangement as set forth in claim 6, wherein said regulation means are diode means connected in parallel to said resistance means, and connected to said monitoring means in such a manner that said diode means furnish a shunt path for said resistance means upon receipt of said auXiliary signal.
Claim 10
Dependent Claim
44 words
An arrangement as set forth in claim 7, wherein said diode means comprise a first diode having an anode connected to receive said auxiliary signal and a cathode connected to said signal electrode, and a second diode connected in series to said first diode.
Claim 11
Dependent Claim
51 words
An arrangement as set forth in claim 7, wherein said regulation means comprises semi-conductor means connected in parallel with said resistance means, and connected to said monitoring means in such a manner that said semi-conductor means is normally non-conductive and changes to the conductive state upon receipt of said auxiliary signal.
Claim 12
Dependent Claim
41 words
An arrangement as set forth in claim 9, wherein said semi-conductor means comprise a field-effect transistor having a source-drain circuit connected in parallel with said resistance means and having a gate connected to said monitoring means for receiving said auxiliary signal.
Claim 13
Dependent Claim
61 words
An arrangement as set forth in claim 5, wherein said monitoring means comprise a transistor having a base connected to said output of said amplifier means, and having an emitter and a collector; a Zener diode having a first terminal connected to said emitter, and a second terminal; and circuit means connected to said second terminal, for furnishing said auxiliary signal.
Claim 14
Dependent Claim
16 words
An arrangement as set forth in claim 11, wherein said circuit means comprise a resistance-capacitance circuit.
Claim 15
Dependent Claim
29 words
An arrangement as set forth in claim 5, further comprising additional amplification stages connected to said output of said amplifier means for further amplifying said amplified television picture signals.
Claim 16
Dependent Claim
50 words
An arrangement as set forth in claim 5, further comprising means for furnishing a signal corresponding to the average value with respect to time of said amplified television picture signals; wherein said arrangement has an output; further comprising means for connecting said signal to said output during said retrace intervals.
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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) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |