Circuit for curve display on visual viewing screen - has comparison and anti-valence circuits enabling closed curves to be presented

摘要

The circuit is for displaying curves on the screen of a visual display working on the line raster principle has a line counter summing line pulses, a column counter summing time pulses of higher frequency than the line pulses, and an image reproduction store. It is designed to accommodate closed curve paths in association with an abscissa in the line direction. Digital data is read from the store in synchronisation with time pulses as each line in turn is scanned. A comparator outputs one of two signals corresp. to the value of the digital data w.r.t. the line counter status. A register holds the comparator output for a time pulse duration and is connected to an antivalence element input. Another input is connected to the comparator output directly. The antivalence element controls the beam intensity.