METHOD AND CIRCUIT FOR CONTROLLING CONTRAST OF BACKGROUND AREA

摘要

PURPOSE: A method and a circuit for contrast control of a background area are provided to control the contrast of a background area or a gain of a video signal by a user, thereby providing various contents of a highlighting area in the optimum state. CONSTITUTION: A circuit for contrast control of a background area includes an IBLK generating circuit(41) and an amplifier(45). The IBLK generating circuit received position data and area data input serially via an SDA(Serial DAta line) in response to horizontal and vertical synchronizing signals, and outputs a highlighting enable signal and parallel data(12C_data) to the amplifier. The amplifier controls a gain and/or width of R,G,B video signals(RIN,GIN,BIN) corresponding to the highlighting enable signal and outputs R,G,B video signals(ROUT,GOUT,BOUT), of which contrast and/or sharpness is controlled. The amplifier includes a control signal generating circuit, a highlighting area contrast control circuit, and a background area contrast control circuit.