Apparatus and method for controlling a monitor using first and second

Abstract

A monitor control device for use in a CRT-type of monitor which receives video signals and synchronizing signals from a host computer and provides a visual display of information on a screen. The monitor control device includes a polarity converter for converting polarities of synchronizing signals into the same polarity; a bias adjusting circuit for receiving a first color signal including a first clock signal and a second color signal including a monitor control information signal, and adjusting respective DC bias voltages of the first and the second color signals to a zero level so as to output bias voltage adjusted color signals; an signal extracting circuit for extracting the first clock signal and the monitor control information signal from the bias voltage adjusted color signals; a micro controller for receiving the first clock signal and the monitor control information signal from the extracting circuit during a vertical synchronization period of the synchronizing signals, and generating a second clock signal and a plurality of function control signals corresponding to the first clock signal and the monitor control information signal, respectively, while the monitor control information signal is effective; and a monitor function adjusting circuit responsive to the function control signals, for adjusting functions of the monitor control apparatus in synchronization with the second clock signal so as to display information on the screen. The monitor control device allows the user to control a variety of monitor functions from the host computer without the use of a RS232C cable and its RS232C interface between the monitor and the host computer.