Title:
PICTURE QUALITY CONTROL CIRCUIT
Document Type and Number:
Japanese Patent JPS63169895
Kind Code:
A
Abstract:
PURPOSE:To reduce the circuit area and to decrease the number of parts of a picture quality control circuit by using a variable gain control circuit consisting of two double balanced differential amplifiers whose gains can be controlled in response to the DC voltage for a TV receiver. CONSTITUTION:The video signals supplied from an input terminal 105 are applied to a delay line 103 having its delay time tau as ell as to an input terminal 106 of a 1st double balanced differential amplifier 101. The delay signals passed through the line 103 are applied to a delay line 104 having a delay time tau and to a common input terminal 108 for 1st and 2nd input terminals of a 2nd double balanced differential amplifier 102. The delay signals passed through the line 104 are applied to a 2nd input terminal 107 of the amplifier 101. The signals supplied to input terminals 106-108 are synthesized and outputted through an output terminal 109. In such a way, a secondary differential waveform is produced and added to an original signal concurrently with control of the correction value for output by means of both amplifiers 101 and 102.
Inventors:
MURAKAMI MASAHARU
Application Number:
JP146587A
Publication Date:
July 13, 1988
Filing Date:
January 07, 1987
Export Citation:
Assignee:
TOSHIBA CORP
International Classes:
H04N9/68; (IPC1-7): H04N9/68
Attorney, Agent or Firm:
Takehiko Suzue