Abstract: To provide an OSD circuit needing little load for the control command transfer for displaying a background color, a OSD circuit of the invention comprises a background color control circuit (4) for out-putting three color signals and a blanking signal generated by a character generator (3), when a background control signal supplied from the command processor is inactive, said background control signal made active when the video picture is to be replaced with a background color, and outputting the three color signals generated by the character generator during the blanking signal is active and background color signals for displaying the background color during the blanking signal is inactive, together with a background blanking signal for suppressing signals of all of the video picture instead of the blanking signal, when the background control signal is active.

Abstract: An apparatus for inserting color character data into a composite video signal, comprises a display controller determining a character display position on the basis of a horizontal synchronizing signal and a vertical synchronizing signal to generate a character generation timing signal and a character output timing signal. A character generator receives the character generation timing signal and generates a character color data signal and a character dot data signal, which are used for controlling the kind of a character to be displayed. A luminance signal generator receives the character color data signal and generates a luminance component control signal controlling a luminance component of the character to be displayed.

Abstract: An automatic frequency control circuit includes a phase comparator, a voltage-controlled oscillator, a frequency divider, a decoder, and a discriminating circuit. The phase comparator compares a phase of an input signal of a horizontal sync signal for television with a phase of a signal phase-locked with the horizontal sync signal to generate a control voltage. The VCO outputs a VCO signal having a frequency controlled by the control voltage. The frequency divider divides a frequency of the VCO signal and outputs an intermediate frequency division ratio signal and the phase-locked signal serving as a terminal frequency division ratio output. A decoder logically processes the phase-locked signal, the intermediate frequency division ratio signal, and the VCO signal and outputs a horizontal sync signal phase-locked with the horizontal sync signal.