US 5,345,264 A · Video signal processing circuit for a video camera using a luminance signal

Abstract

Auto focus control and/or auto exposure control is carried out by using a luminance signal before gamma correction, before addition of aperture signal but after hand shake correction. Auto white balance control is carried out by using a color signal after hand shake correction. Consequently, precise auto focus control, auto exposure control and/or auto white balance control can be done. The field memory for electronic zooming and/or hand shake correction is also used as a field memory for noise reduction. Consequently, a video signal processing circuit which is inexpensive and simple can be implemented.

Claims9

Dependent claims

A video signal processing circuit for a video camera, comprising:

Y/C separating means for separating a video signal obtained by AD conversion of an output from an image pickup device to a luminance signal and a color signal for outputting;
and
auto focus accumulating means for accumulating, at a prescribed period, high frequency component of the luminance signal outputted from said Y/C separating means before gamma correction, for outputting the result as an auto focus reference signal for automatic focus adjustment.

Dependencies are inferred from the claim text.

Facts

Application

08/021,590Filed 24 Feb 1993

Priority

JP 4-4120527 Feb 1992

Granted

6 Sep 1994

Term ends

Not estimatedThe source records don’t support an estimate.

Classification8 codes

H04N 23/68
Control of cameras or camera modules: for stable pick-up of the scene, e.g. compensating for camera body vibrations
H04N 23/673
Focus control based on electronic image sensor signals: based on contrast or high frequency components of image signals, e.g. hill climbing method
H04N 23/6811
Motion detection: based on the image signal
H04N 23/683
Vibration or motion blur correction: performed by a processor, e.g. controlling the readout of an image memory

Video signal processing circuit for a video camera using a luminance signal

Life of this patent

Video signal processing circuit for a video camera using a luminance signal

Life of this patent

Abstract

Claims9