Illumination flicker correction for video cameras

Assignee: Panasonic Holdings Corp

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Filing: 1992-03-25

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Granted: —

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Expires: 2012-03-25

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Abstract

Abstract A flicker correcting circuit for reducing a large, rapid change in signal level generated in a case where a CCD television camera or the like is operated in the shutter mode, and for obtaining a flickerless, high-quality video signal for an object illuminated with a fluorescent lamp, is disclosed, in which the level of a video signal from a CCD (1) is detected at each field by a signal processor (4), and a microcomputer (5) controls a shutter pulse generating circuit (6) so that a shutter pulse for controlling the charge storage period of the CCD is delivered from the shutter pulse generating circuit to the CCD in accordance with the detected level at each field.

Inventors

👤 Hidetoshi Mimura
👤 Haruo Kogane

Bibliographic Details

Application Number —

Jurisdiction EP

Data Source google_patents

Last Synchronized 2026-11-09 12:40

CPC Classifications

H; H04; H04N; H04N23/00; H04N23/70; H04N23/745

Claims Analysis

Total Claims: 4

Claim 1

Independent Claim 89 words

A flicker correcting circuit comprising: a solid-state imaging element (1); a shutter pulse generating circuit (6) for sending out a shutter pulse to the solid-state imaging element; a signal processor (4) for detecting the level of a video signal at each field, the video signal being delivered from the solid-state imaging element; and control means (5) for causing the shutter pulse generating circuit to send out the shutter pulse at each field in accordance with the detected level, to control the charge storage period of the solid-state imaging element.

Claim 2

Dependent Claim 105 words

A flicker correcting circuit comprising: a solid-state imaging element (1); a shutter pulse generating circuit (6) for sending out a shutter pulse to the solid-state imaging element; an amplifier (2) for amplifying a video signal delivered from the solid-state imaging element; a signal processor (4) for detecting the level of the output signal of the amplifier at each field; and control means (5) for causing the shutter pulse generating circuit to send out the shutter pulse at each field and for controlling the amplifier, in accordance with the detected level, the charge storage period of the solid-state imaging element being controlled by the shutter pulse.

Claim 3

Dependent Claim 61 words

A flicker correcting circuit according to Claim 1, wherein the shutter pulse for controlling the charge storage period of the solid-state imaging element in accordance with a portion of the video signal outputted therefrom is delivered from the shutter pulse generating circuit, when a time corresponding to three fields has elapsed after the signal portion was detected by the signal processor.

Claim 4

Dependent Claim 62 words

A flicker correcting circuit according to Claim 2, wherein the shutter pulse for controlling the charge storage period of the solid-state imaging element in accordance with a portion of the output signal of the amplifier is delivered from the shutter pulse generating circuit, when a time corresponding to three fields has elapsed after the signal portion was detected by the signal processor.

References Cited (Backward Citations)

US4670787A Cited

US4879591A Cited

WO1990004303A2 Cited

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