公开(公告)号：US3540011A

公开(公告)日：1970-11-10

申请号：US3540011D

申请日：1968-09-06

Applicant: PHILIPS CORP

Inventor： STUPP EDWARD H ,  CATH PIETER G ,  SZILAGYI ZSOLT

IPC: G11C11/36 ,  G11C11/42 ,  H01L27/146 ,  H04N5/369

CPC classification number: H01L27/14643 ,  H04N5/374

公开(公告)号：US3584146A

公开(公告)日：1971-06-08

申请号：US3584146D

申请日：1968-11-21

Applicant: PHILIPS CORP

Inventor： CATH PIETER G ,  STUPP EDWARD H ,  RITTNER EDMUND S

IPC: H04N5/217 ,  H04N5/232 ,  H04N5/353 ,  H04N5/361 ,  H04N5/38

CPC classification number: H04N5/217

Abstract: Dark current compensation in a video imaging tube is accomplished by virtue of establishing a dark current level and subtracting it from the video signal. The dark current level can be established by overscanning or scanning a nonexposed area of the image tube or by means of a compensating video sensing segment positioned directly on the actual video sensing segment. In a silicon target tube, the compensating junction can consist of a conveniently sized assembly or mosaiced junctions similar to those of the target, and connected in parallel with the target. The subtraction signal can then be placed in a sample and hold circuit, averaged and subtracted from the actual video signal during a successive scan.