Cathode ray tube burn compensation

摘要

Compensation for phosphor burn in a CRT scanner is achieved by offsetting the scan by half a line spacing on alternate scans when the film is stationary in the scanner. To avoid unpleasant effects the offset scan output is supressed and the previous frame output frozen in the frame store 24. The previous frame is output again from the frame store in place of the offset scan output. Offset scanning is not performed when a control adjustment is made to avoid a juddering effect on the displayed output.