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JPS57212871A - Black level stabilizing circuit - Google Patents

Black level stabilizing circuit

Info

Publication number
JPS57212871A
JPS57212871A JP56097562A JP9756281A JPS57212871A JP S57212871 A JPS57212871 A JP S57212871A JP 56097562 A JP56097562 A JP 56097562A JP 9756281 A JP9756281 A JP 9756281A JP S57212871 A JPS57212871 A JP S57212871A
Authority
JP
Japan
Prior art keywords
black level
signal
level
false
base
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.)
Pending
Application number
JP56097562A
Other languages
Japanese (ja)
Inventor
Hiroshi Kaneko
Yukimi Saeki
Osanori Watanabe
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP56097562A priority Critical patent/JPS57212871A/en
Publication of JPS57212871A publication Critical patent/JPS57212871A/en
Pending 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
    • H04N5/16—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

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Picture Signal Circuits (AREA)

Abstract

PURPOSE:To stably reproduce a black level, by inserting a false black level having a value corresponding to an amplitude of a video signal to a vertical blancing part and controlling a DC level of a video signal with the false black level. CONSTITUTION:A blanking pulse is applied to the base of a transistor (TR)8, a DC output voltage of a contrast adjusting variable resistor 5 is applied to the collector via level shift diodes D1-D3, and a false black level signal is obtained at the emitter. The false black level signal and a luminance adjusting DC voltage determined with resistors R16 and R17 are applied to the base of a TR1, and a video signal from a pedestal clamp circuit is applied to the base of a TR2 in which the emitter and the collector are commonly connected to the TR1. A signal outputted from the common emitter is applied to a black peak detection circuit 8, the obtained black peak voltage is amplified at a correction circuit 9 and applied to a final stage video amplifier 4 as a control voltage.
JP56097562A 1981-06-25 1981-06-25 Black level stabilizing circuit Pending JPS57212871A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56097562A JPS57212871A (en) 1981-06-25 1981-06-25 Black level stabilizing circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56097562A JPS57212871A (en) 1981-06-25 1981-06-25 Black level stabilizing circuit

Publications (1)

Publication Number Publication Date
JPS57212871A true JPS57212871A (en) 1982-12-27

Family

ID=14195669

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56097562A Pending JPS57212871A (en) 1981-06-25 1981-06-25 Black level stabilizing circuit

Country Status (1)

Country Link
JP (1) JPS57212871A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6149558A (en) * 1984-08-18 1986-03-11 Matsushita Electric Ind Co Ltd Direct current regenerating circuit
JPS61242472A (en) * 1985-04-19 1986-10-28 Matsushita Electric Ind Co Ltd Dc restoration
US5334998A (en) * 1991-07-05 1994-08-02 Sun Microsystems, Inc. Method and apparatus for utilizing blanking on both zero setup and pedestal setup display monitors with a conventional computer system

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS517820A (en) * 1974-07-08 1976-01-22 Mitsubishi Electric Corp
JPS5326A (en) * 1976-06-22 1978-01-05 Admiral Corp Video signal amplifier for television receiver
JPS553540B2 (en) * 1973-07-25 1980-01-25

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS553540B2 (en) * 1973-07-25 1980-01-25
JPS517820A (en) * 1974-07-08 1976-01-22 Mitsubishi Electric Corp
JPS5326A (en) * 1976-06-22 1978-01-05 Admiral Corp Video signal amplifier for television receiver

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6149558A (en) * 1984-08-18 1986-03-11 Matsushita Electric Ind Co Ltd Direct current regenerating circuit
JPS61242472A (en) * 1985-04-19 1986-10-28 Matsushita Electric Ind Co Ltd Dc restoration
US5334998A (en) * 1991-07-05 1994-08-02 Sun Microsystems, Inc. Method and apparatus for utilizing blanking on both zero setup and pedestal setup display monitors with a conventional computer system

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