Apparatus and method for controlling brightness in a monitor screen

摘要

There is provided a device for controlling the brightness of a monitor screen to prevent the edge of the screen from appearing darker than the center of the screen by setting a black level signal scanned to the edge of the screen to be greater than a black level signal scanned to the center of the screen. The device includes a parabolic signal generator for generating a parabolic signal. A video output signal generator receives a video input signal in which an image is carried on a black level signal voltage and a brightness control voltage for controlling the brightness of the screen. The video output signal generator generates a first video output signal having a black level signal adjusted by the brightness control voltage. A signal synthesizer receives the first video output signal and the parabolic signal and generates therefrom a second video output signal in which the parabolic signal is added to the first video output signal.