Circuit for Selection of Colour or Grey Level Display
Original Publication Date: 1985-Oct-01
Included in the Prior Art Database: 2005-Feb-19
A circuit using TTL (transistor-transistor logic) modules is disclosed which provides a colour display or a display with up to eight grey levels. A set of fixed resistors controls the gamma characteristics of the display. The circuit includes a logic switch to select either a seven colour display or an eight grey level display. In addition, each beam may be turned off selectively to allow grey level display in each of seven basic colours. Various applications of the circuit are described including anti-aliasing and colour overlay on grey level facsimile. The circuit diagram illustrates the selection of colour or grey level display using a total of 14 TTL modules and a number of fixed resistors. Input colour digital signals are RIN, GIN and BIN .