Abstract: In a circuit and method of controlling the horizontal and vertical screen sizes of a cathode ray tube (CRT) monitor, the circuit includes a horizontal screen size compensation circuit, an east-west correction signal controller, a vertical screen size compensation circuit, and a vertical screen size correction signal controller. The horizontal screen size compensation circuit compares the voltage value of a horizontal screen size correction signal with the voltage value of a horizontal reference voltage to obtain first and second horizontal current signals. In response to a horizontal control signal, the horizontal screen size compensation circuit outputs a horizontal correction current signal obtained by subtracting a horizontal variable current signal from the first horizontal current signal.

Abstract: A system and method for controlling the horizontal size of a monitor screen are provided. The provided system for controlling the horizontal size of a monitor screen includes a processor, a driving circuit, and a microcomputer. Here, the processor generates a calibration signal to control the horizontal size of a monitor screen, in response to predetermined control signals. The driving circuit receives the calibration signal and controls the driving capacity of the calibration signal according to an external load to output the calibration signal. The microcomputer generates the control signals.

Abstract: An on-screen display system is adapted for displaying OSD information on an OSD background portion which is selectively filled with either an half tone video image or a background raster of a specific color selected by a user, or which is filled by superimposing the half tone video image and the half tone background raster selected by the user. Mixing and amplifying circuits are provided for each of three red/green/blue (R/G/B) channels. Each of the three mixing and amplifying circuits receives a video signal and an OSD signal of a respective channel, mixes the video signal and the OSD signal according to a video selection signal and an OSD selection signal, amplifies a mixed signal, and outputs an amplified image signal to a display. A selection signal generating circuit receives OSD signals for R/G/B channels, a video/OSD switching signal, a half tone signal, and OSD control signals generates and outputs the OSD selection signal and the video selection signal.