GB538947A - Improvements in television signal-translating systems - Google Patents

Improvements in television signal-translating systems

Info

Publication number
GB538947A
GB538947A GB32445/39A GB3244539A GB538947A GB 538947 A GB538947 A GB 538947A GB 32445/39 A GB32445/39 A GB 32445/39A GB 3244539 A GB3244539 A GB 3244539A GB 538947 A GB538947 A GB 538947A
Authority
GB
United Kingdom
Prior art keywords
signals
valve
accordance
signal
grids
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB32445/39A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BAE Systems Aerospace Inc
Original Assignee
Hazeltine Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hazeltine Corp filed Critical Hazeltine Corp
Publication of GB538947A publication Critical patent/GB538947A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/14—Picture signal circuitry for video frequency region
    • H04N5/20—Circuitry for controlling amplitude response
    • H04N5/202—Gamma control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/14—Picture signal circuitry for video frequency region
    • H04N5/16—Circuitry for reinsertion of dc and slowly varying components of signal; Circuitry for preservation of black or white level
    • H04N5/165—Circuitry for reinsertion of dc and slowly varying components of signal; Circuitry for preservation of black or white level to maintain the black level constant

Abstract

538,947. Television ; valve amplifying circuits. HAZELTINE CORPORATION. Dec. 18, 1939, Nos. 32445 and 32446. Convention dates, Jan. 14 and Jan. 27. [Classes 40 (iii) and 40 (v)] The contrast or gamma of .a television receiver is automatically varied in accordance with (1) the instantaneous value of the signal, e.g. by feeding the signals to two grids of the same valve, or (2) the general brightness of the subject or average intensity of the signal. Signals derived from different points of a potentiometer 22 following the video-frequency amplifier 16 are fed through amplifiers 23, 30 to the first and third grids of the valve 21, diodes 24, 31 deriving bias voltages equal to the peak value of the signal to supplement the fixed bias.voltages and representing the uni-directional background illumination components. The non- linear amplification of the signals in accordance with their instantaneous values constitutes an automatic gamma control. This control may be varied in accordance with the average intensity of the signals by applying to the grid of valve 30 a further biasing voltage derived by the rectifier 38 receiving part of the video signals.
GB32445/39A 1939-01-14 1939-12-18 Improvements in television signal-translating systems Expired GB538947A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US250914A US2255691A (en) 1939-01-14 1939-01-14 Television signal-translating system

Publications (1)

Publication Number Publication Date
GB538947A true GB538947A (en) 1941-08-22

Family

ID=22949682

Family Applications (1)

Application Number Title Priority Date Filing Date
GB32445/39A Expired GB538947A (en) 1939-01-14 1939-12-18 Improvements in television signal-translating systems

Country Status (4)

Country Link
US (1) US2255691A (en)
BE (1) BE437358A (en)
FR (1) FR862876A (en)
GB (1) GB538947A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE955779C (en) * 1952-05-07 1957-01-10 Philips Nv Circuit arrangement for regulating the gradation of an image signal
US4799106A (en) * 1985-08-22 1989-01-17 Rank Pullin Controls Limited Controlling image signals in an imaging apparatus

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2594870A (en) * 1945-11-29 1952-04-29 Us Navy Indicator
US2548436A (en) * 1946-01-25 1951-04-10 Hazeltine Corp Television receiver background control circuit
US2519238A (en) * 1947-04-05 1950-08-15 Rca Corp Biased diode wave shaping circuit
US2552588A (en) * 1947-04-26 1951-05-15 Columbia Broadeasting System I Gamma control circuit
US2692299A (en) * 1948-12-11 1954-10-19 Westinghouse Electric Corp Image contrast intensifier
US2569297A (en) * 1948-12-16 1951-09-25 Rca Corp Direct-current restoring apparatus
US2740071A (en) * 1950-05-11 1956-03-27 Columbia Broadcasting Syst Inc Television
US2760008A (en) * 1950-08-30 1956-08-21 Rca Corp Amplifier having controllable signal expansion and compression characteristics
FR2117909B1 (en) * 1970-12-16 1976-12-03 Fernseh Gmbh
JPS56107674A (en) * 1980-01-31 1981-08-26 Sony Corp Gradation correcting device of video signal
JPS627290A (en) * 1985-07-04 1987-01-14 Fuji Photo Film Co Ltd Gradient correction for color negative film picking up image and its device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE955779C (en) * 1952-05-07 1957-01-10 Philips Nv Circuit arrangement for regulating the gradation of an image signal
US4799106A (en) * 1985-08-22 1989-01-17 Rank Pullin Controls Limited Controlling image signals in an imaging apparatus

Also Published As

Publication number Publication date
US2255691A (en) 1941-09-09
BE437358A (en)
FR862876A (en) 1941-03-18

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