BEAM INDEX COLOR CATHODE RAY TUBE

摘要

A beam index color cathode ray tube has index stripes spaced apart across a run-in area of the screen which have a pitch substantially equal to the pitch of index stripes in an image area, and a predetermined number of the index stripes in the run-in area are counted as an electron beam scans them to preset color control circuits to a predetermined condition at the commencement of scanning of the image area. A characteristic of the signal resulting from scanning of the index stripes may be used to begin the counting thereof from a specific one of the index stripes in the run-in area other than the first one encountered by the electron beam.