Device for and method of controlling osd in muting video signals

Abstract

A device for controlling an OSD in muting video signals is adapted to eliminate an after-image of the OSD when muting the video signals in a display monitor having an OSD function by use of both hardware and software. The device includes: a microcomputer for generating a cut-off signal to mute the video signals upon sensing a variation in horizontal and vertical sync signals fed thereto by a video card, and for generating a blank signal by executing an OSD erase control program for erasing the OSD; an OSD IC for saving the blank signal in a random access memory (RAM) by means of an OSD erase section when variation in the horizontal and vertical sync signals provided to the microcomputer is sensed, and for generating the blank signal according to an OSD control signal; and a video pre-amplifier and a video main amplifier responsive to the cut-off signal generated by the microcomputer for muting the video signals, and for applying the blank signal to a CRT to erase the OSD displayed thereon.

Dependencies are inferred from the claim text.