Cathode ray tube display apparatus

Abstract

Cathode ray tube display apparatus comprises a cathode ray tube display screen for displaying successive frames of a non-interlaced video image in response to excitation by at least one raster-scanned electron beam. A line timebase circuit sequentially addresses each electron beam to successive pixels on the screen in a line of a raster in response to a line timebase sync signal. A frame timebase circuit sequentially addresses each electron beam to successive lines of the raster in response to a frame timebase sync signal. The frame timebase circuit comprises means for offsetting successive frames of the video image in a direction transverse of the lines of the raster by a distance less than the spacing of adjacent lines of the raster. Gaps between adjacent pixels on successive lines of the raster are made invisible to the viewer because the persistence of viewer's eye effectively integrates the image content of successive frames. Also, because the successive frames have the same image content, there is no low-frequency component in the image spectrum below the frame timebase frequency. Therefore, the displayed image is free from objectionable flicker.

Dependencies are inferred from the claim text.