Generation of TV image of drawing - employs memory systems to provide contour line around specific area

摘要

The points in a TV image frame are stored in a memory and the image is generated by exploring the memory contents in synchronism with the image sweep. This enables drawings to be displayed with a contour line surrounding an area on the image. A luminous probe (3) placed in front of the screen (2) of a tube (1) sends a position signal to a keyboard (30) each time the beam passes. The keyboard is connected to a memory (20) and output (40) circuits so that memory assemblies (22) of the write control circuits (23) can be addressed by a multiplexer (21). The memory assembly contains colour memories (221,222,223) and a zone contour memory (CZ) which are explored in parallel under control from a time base (10) which ensures synchronism with the image sweep. The video output signals are applied to the image screen and to a video monitor (5).