JPS56140776A - Luminance control circuit - Google Patents

Luminance control circuit

Info

Publication number
JPS56140776A
JPS56140776A JP4298980A JP4298980A JPS56140776A JP S56140776 A JPS56140776 A JP S56140776A JP 4298980 A JP4298980 A JP 4298980A JP 4298980 A JP4298980 A JP 4298980A JP S56140776 A JPS56140776 A JP S56140776A
Authority
JP
Japan
Prior art keywords
voltage
luminance control
luminance
transistor
control circuit
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
JP4298980A
Other languages
Japanese (ja)
Other versions
JPS6339151B2 (en
Inventor
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 JP4298980A priority Critical patent/JPS56140776A/en
Publication of JPS56140776A publication Critical patent/JPS56140776A/en
Publication of JPS6339151B2 publication Critical patent/JPS6339151B2/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
    • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
    • H04N5/57—Control of contrast or brightness

Landscapes

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

Abstract

PURPOSE:To obtain a screen which is free from uneven luminance without effected from the video signal or the undesired signal, by connecting the both ends of a clamping capacitor to the both input terminals of a differential amplifier to which both the clamp voltage and the luminance control voltage are applied. CONSTITUTION:The video signal is applied to a pair of switching transistors 5 and 6 via the control circuit 2 and transistor 3, and these transistors conduct only in the pedestal period and by the clamp pulse of the terminal 10. And the voltage is accumulated to the clamping capacitor 7. On the other hand, the luminance control voltage obtained at the variable resistance 16 is applied to the transistor 15 of a differential amplifier, and the output is fed back continuously to the control circuit 2 until a coincidence is obtained between the clamp voltage applied to the transistor 14 and the luminance control voltage. Then the DC level of the video signal is set at the voltage which is controlled by the variable resistance 16. The clamping capacitor 7 in such circuit is connected to both input terminals of a differential amplifier. In such way, the AC component is negated to ensure a good luminance control with no uneven luminance.
JP4298980A 1980-04-01 1980-04-01 Luminance control circuit Granted JPS56140776A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4298980A JPS56140776A (en) 1980-04-01 1980-04-01 Luminance control circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4298980A JPS56140776A (en) 1980-04-01 1980-04-01 Luminance control circuit

Publications (2)

Publication Number Publication Date
JPS56140776A true JPS56140776A (en) 1981-11-04
JPS6339151B2 JPS6339151B2 (en) 1988-08-03

Family

ID=12651433

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4298980A Granted JPS56140776A (en) 1980-04-01 1980-04-01 Luminance control circuit

Country Status (1)

Country Link
JP (1) JPS56140776A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4994756A (en) * 1987-05-02 1991-02-19 U.S. Philips Corporation Circuit arrangement for amplifying a television signal

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54177852U (en) * 1978-06-06 1979-12-15

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54177852U (en) * 1978-06-06 1979-12-15

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4994756A (en) * 1987-05-02 1991-02-19 U.S. Philips Corporation Circuit arrangement for amplifying a television signal

Also Published As

Publication number Publication date
JPS6339151B2 (en) 1988-08-03

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