JPS5566178A - Shading correction circuit - Google Patents

Shading correction circuit

Info

Publication number
JPS5566178A
JPS5566178A JP13895678A JP13895678A JPS5566178A JP S5566178 A JPS5566178 A JP S5566178A JP 13895678 A JP13895678 A JP 13895678A JP 13895678 A JP13895678 A JP 13895678A JP S5566178 A JPS5566178 A JP S5566178A
Authority
JP
Japan
Prior art keywords
output
amplifier
correcting
circuit
parabola
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
JP13895678A
Other languages
Japanese (ja)
Inventor
Hisatoshi Aoki
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.)
Toshiba Corp
Original Assignee
Toshiba Corp
Tokyo Shibaura Electric 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 Toshiba Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP13895678A priority Critical patent/JPS5566178A/en
Publication of JPS5566178A publication Critical patent/JPS5566178A/en
Pending legal-status Critical Current

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  • Picture Signal Circuits (AREA)

Abstract

PURPOSE: To secure the correction for the luminance without any expertness by providing the saturation region to the gain control amplifier of the device and then giving a comparison between the saturation level and the shading correcting waveform.
CONSTITUTION: The HD (horizontal drive) and VD (vertical drive) pulses turn into the saw-tooth waves through saw-tooth wave formation circuits 1 and 2 to form the parabola waveforms through parabola wave formation circuits 3 and 4 each. These parabola waves are compounded at 3rd compounding circuit 11 via 1st and 2nd compounding circuits 9 and 10 to be led into signal correcting amplifier 20. And the output of the waveform the upper areas of which near the rise and fall reached the gain saturation region are cut off is applied to gain control amplifier 8. In this connection, amplifier 8 is controlled by the output of amplifier 20 and then controls the contrast component of the video signal to lead out the correcting video signal. On the other hand, the output of amplifier 20 is applied to peak detector circuit 23, and the peak level is given to comparator 21 as the reference level for the comparison with the output of circuit 11. And in case the peak level is higher than the output, analog switch 22 is closed. Then the peak level is applied to 4th compounding circuit 7 to obtain the correcting output.
COPYRIGHT: (C)1980,JPO&Japio
JP13895678A 1978-11-13 1978-11-13 Shading correction circuit Pending JPS5566178A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP13895678A JPS5566178A (en) 1978-11-13 1978-11-13 Shading correction circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP13895678A JPS5566178A (en) 1978-11-13 1978-11-13 Shading correction circuit

Publications (1)

Publication Number Publication Date
JPS5566178A true JPS5566178A (en) 1980-05-19

Family

ID=15234085

Family Applications (1)

Application Number Title Priority Date Filing Date
JP13895678A Pending JPS5566178A (en) 1978-11-13 1978-11-13 Shading correction circuit

Country Status (1)

Country Link
JP (1) JPS5566178A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58144959U (en) * 1982-03-26 1983-09-29 日立電子株式会社 Shading correction circuit
US4731652A (en) * 1986-03-25 1988-03-15 Kabushiki Kaisha Toshiba Shading correction signal generating device for a television camera apparatus
US5343302A (en) * 1991-11-15 1994-08-30 Sony Corporation Video camera with improved shading correction using clipped parabolic wave signal

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58144959U (en) * 1982-03-26 1983-09-29 日立電子株式会社 Shading correction circuit
US4731652A (en) * 1986-03-25 1988-03-15 Kabushiki Kaisha Toshiba Shading correction signal generating device for a television camera apparatus
US5343302A (en) * 1991-11-15 1994-08-30 Sony Corporation Video camera with improved shading correction using clipped parabolic wave signal

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