JPS567574A - Black level detection circuit for video signal - Google Patents

Black level detection circuit for video signal

Info

Publication number
JPS567574A
JPS567574A JP8363179A JP8363179A JPS567574A JP S567574 A JPS567574 A JP S567574A JP 8363179 A JP8363179 A JP 8363179A JP 8363179 A JP8363179 A JP 8363179A JP S567574 A JPS567574 A JP S567574A
Authority
JP
Japan
Prior art keywords
circuit
video signal
transistor
detection circuit
level detection
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.)
Granted
Application number
JP8363179A
Other languages
Japanese (ja)
Other versions
JPS6318385B2 (en
Inventor
Namio Yamaguchi
Minoru Miyata
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co 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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP8363179A priority Critical patent/JPS567574A/en
Publication of JPS567574A publication Critical patent/JPS567574A/en
Publication of JPS6318385B2 publication Critical patent/JPS6318385B2/ja
Granted 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

Landscapes

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

Abstract

PURPOSE:To make suitable the circuit for circuit integration, by avoiding the dispersion of the characteristics and reducing the number of terminals, through the application of bias from the common bias circuit to two constant current sources connected to the video output transistor. CONSTITUTION:The series circuit of the transistor 8 for constant current source, diode 9 and resistance 10 is connected in parallel with the collector of the transistor TR1, the variable resistor 12 is connected to the video signal output terminal 11 of the emitter of TR1, the resistances 13, 14 for reference voltage are taken as the fixed resistances, and the collector of TR1 is connected to the base of TR4 via TR15. With this constitution, in the case of circuit integration, the connection terminal of the variable resistance 12 and the output terminal of video signal are realized by the common terminal 11 and each resistor can be biased by a common bias circuit.
JP8363179A 1979-07-02 1979-07-02 Black level detection circuit for video signal Granted JPS567574A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8363179A JPS567574A (en) 1979-07-02 1979-07-02 Black level detection circuit for video signal

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8363179A JPS567574A (en) 1979-07-02 1979-07-02 Black level detection circuit for video signal

Publications (2)

Publication Number Publication Date
JPS567574A true JPS567574A (en) 1981-01-26
JPS6318385B2 JPS6318385B2 (en) 1988-04-18

Family

ID=13807805

Family Applications (1)

Application Number Title Priority Date Filing Date
JP8363179A Granted JPS567574A (en) 1979-07-02 1979-07-02 Black level detection circuit for video signal

Country Status (1)

Country Link
JP (1) JPS567574A (en)

Also Published As

Publication number Publication date
JPS6318385B2 (en) 1988-04-18

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