GB683605A - Improvements relating to television apparatus employing non-linear circuits - Google Patents

Improvements relating to television apparatus employing non-linear circuits

Info

Publication number
GB683605A
GB683605A GB10953/48A GB1095348A GB683605A GB 683605 A GB683605 A GB 683605A GB 10953/48 A GB10953/48 A GB 10953/48A GB 1095348 A GB1095348 A GB 1095348A GB 683605 A GB683605 A GB 683605A
Authority
GB
United Kingdom
Prior art keywords
diode
valve
conductive
cathode
linear
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
GB10953/48A
Inventor
Eric Lawrence Casling White
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.)
EMI Ltd
Electrical and Musical Industries Ltd
Original Assignee
EMI Ltd
Electrical and Musical Industries Ltd
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 EMI Ltd, Electrical and Musical Industries Ltd filed Critical EMI Ltd
Publication of GB683605A publication Critical patent/GB683605A/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

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Picture Signal Circuits (AREA)
  • Video Image Reproduction Devices For Color Tv Systems (AREA)
  • Electrophonic Musical Instruments (AREA)

Abstract

683,605. Electric analogue computing systems. ELECTRIC & MUSICAL INDUSTRIES, Ltd. March 26, 1949 [April 21, 1948], No. 10953/48. Class 37. [Also in Group XL (c)] A non-linear circuit for modifying the contrast of television signals comprises a valve to the grid of which the signals are fed and having a cathode feed-back impedance across which is connected a series combination of a linear impedance and a non-linear impedance the modified signals being derived from an intermediate point on the series combination. The output of a cathode follower circuit 1, 8 in the head amplifier of a television camera is applied to the following valve 9 through a first potentiometer comprising resistor 10 and diode 16 and a second potentiometer comprising resistor 11 and diode 17. The anodes of the diodes are biased from a source 7 to be normally non-conductive the anode of diode 17 having a greater bias than that of diode 16. As the instanteous value of the input potential increases diode 16 first becomes conductive and then diode 17 so that the attenuation progressively increases. By a suitable choice of components an approximately exponential characteristic may be obtained. Inductors 12 and 13 and capacitor 25 compensate for any loss in high frequency response. In an alternative arrangement (Fig. 3, not shown), the diodes in parallel with resistors are arranged in series in the connection between the cathode of valve 1 and the grid 9 and become success. ively non-conductive as the input potential increases. Specification 536,089 is referred to.
GB10953/48A 1948-04-21 1948-04-21 Improvements relating to television apparatus employing non-linear circuits Expired GB683605A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB281913X 1948-04-21
GB260349X 1949-03-26

Publications (1)

Publication Number Publication Date
GB683605A true GB683605A (en) 1952-12-03

Family

ID=26258026

Family Applications (1)

Application Number Title Priority Date Filing Date
GB10953/48A Expired GB683605A (en) 1948-04-21 1948-04-21 Improvements relating to television apparatus employing non-linear circuits

Country Status (2)

Country Link
CH (1) CH281913A (en)
GB (1) GB683605A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1248095B (en) * 1959-04-07 1967-08-24 Standard Elektrik Lorenz Ag Process for influencing the course of contrast when reproducing television images
US3651252A (en) * 1970-01-22 1972-03-21 Polaroid Corp Image reproduction system which detects subject by sensing intensity ratios

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB726134A (en) * 1952-07-26 1955-03-16 Standard Telephones Cables Ltd Gamma correcting and frequency compensating circuit
DE1138424B (en) * 1959-08-04 1962-10-25 Philips Patentverwaltung Circuit arrangement for correcting the gradation of a video signal

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1248095B (en) * 1959-04-07 1967-08-24 Standard Elektrik Lorenz Ag Process for influencing the course of contrast when reproducing television images
US3651252A (en) * 1970-01-22 1972-03-21 Polaroid Corp Image reproduction system which detects subject by sensing intensity ratios

Also Published As

Publication number Publication date
CH281913A (en) 1952-03-31

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