ON-SCREEN DISPLAY CIRCUIT AND VIDEO SIGNAL PROCESSING APPARATUS

摘要

PROBLEM TO BE SOLVED: To display a character or a graphic without impairing visibility even while using an on-screen display (OSD) controller of which the clock frequency is slower than that of a video signal processing circuit.;SOLUTION: An OSD circuit includes: an on-screen control circuit which outputs on-screen data to be used for OSD; a line memory for storing the on-screen data; a frequency divider circuit which frequency-divides a clock signal input to a video signal processing circuit and outputs the clock signal to the on-screen control circuit in accordance with a ratio of a clock frequency of the video signal processing circuit to a clock frequency of the on-screen control circuit; and a superimposing circuit which reads the on-screen data from the line memory and superimposes the on-screen data on a video output signal in response to the clock signal of the video signal processing circuit.;COPYRIGHT: (C)2010,JPO&INPIT