US 6,982,705 B2
Imaging apparatus and method of optical-black clamping
Hiroyasu Kunimi, Kamakura (Japan); Hiroshi Nishiyama, Kanagawa-Ken (Japan); Tetsuya Oura, Yokohama (Japan); Hiroyuki Miyahara, Yokohama (Japan); and Takeshi Ibaraki, Kawasaki (Japan)
Assigned to Victor Company of Japan, Ltd., Yokohama (Japan)
Filed on Feb. 27, 2003, as Appl. No. 10/373,864.
Claims priority of application No. 2002-050580 (JP), filed on Feb. 27, 2002.
Prior Publication US 2003/0160772 A1, Aug. 28, 2003
Int. Cl. G09G 5/00 (2006.01)
U.S. Cl. 345—204 8 Claims
OG exemplary drawing
 
1. An imaging apparatus comprising:
a solid-state image sensing device having an imaging area divided into at least two sub-imaging areas in a horizontal direction in the imaging area, a first optical-black area and a second optical-black area being provided at both edges of the imaging area in the horizontal direction;
an extractor to extract first video signals from a plurality of monitoring areas provided in the sub-imaging areas in the vicinity of the border between the sub-imaging areas; and
an optical-black clamp processor to apply optical-black clamp processing to second video signals output from the sub-imaging areas by subtracting a first optical-black signal indicating an optical black level in the first optical-black area from the second video signal output from one of the sub-imaging areas and subtracting a second optical-black signal indicating an optical black level in the second optical-black area from the second video signal output from the other of the sub-imaging areas, the optical-black clamp processor including:
a detector to detect a level difference between the extracted first video signals;
a calculator to calculate an adjusting value per row of pixels, that provides the smallest level difference per row of pixels in a vertical direction in the imaging area based on the detected level difference;
a plurality of optical-black clampers each subtracting the first optical-black signal from the second video signal output from one of the sub-imaging areas and subtracting the second optical-black signal from the second video signal output from the other of the sub-imaging areas, thus outputting an optical-black-clamped video signal; and
an adjuster to perform adjustments to video-signal levels by multiplying the optical-black-clamped video signal by the adjusting value.