An item consisting of a cathode ray tube and a video pickup tube such as a photomultiplier. The radial sweep of the cathode ray tube sequentially illuminates either an opaque or translucent object such as a map or transparency. The electrical output of the video pickup tube is uniformly related to the input light signal variations caused by the color contrast characteristics of the object being scanned. See also SCANNER, LIGHT GENERATING and VIDEO MAPPING GROUP.
