METHOD AND APPARATUS FOR PRODUCING PERCEPTION OF HIGH QUALITY GRAYSCALE SHADING ON DIGITALLY COMMANDED DISPLAYS

摘要

The perpection of grayscale shading on a digitally commanded display (12) is produced by commanding pixels (12a) of the display with brightness-setting signals (0/17, 1/17, 2/17, ...17/17) of differing average duty cycles. The energization of spatially adjacent pixels (79, P1) is scattered in time and pixels which are energized at the same time (P0) are selected to be spatially scattered (78) so as to avoid the perception of visual disturbances such as flickering and surface streaming. This energization is represented as a placement pattern (77) which includes a previously energized pixel (P0) immediately surrounded by eight pixels (78) energigized at different phases and those eight pixels (78) are surrounded by pixels (79) which are preferred locations for the next pixel-energizing pulse. This pattern (77) is shifted throughout the matrix in correspondance with the movement of the previously energized pixel (P0).