Patent ID: 6072540
Filing Date: 2000-06-06
Classification: H04N

Abstract:
A brightness control apparatus for a video display appliance receiving an input video signal, the brightness control apparatus comprising:a parabolic wave generator for generating a horizontal parabolic wave corresponding to a horizontal sync signal separated from the video signal, and a vertical parabolic wave corresponding to a vertical sync signal separated from the video signal;a first variable amplifying section for amplifying the horizontal parabolic wave generated from the parabolic wave generator and being variable by a user of the apparatus;a second variable amplifying section for amplifying the vertical parabolic wave generated from the parabolic wave generator and being variable by a user of the apparatus;a signal superimposing section for superimposing both the horizontal and vertical parabolic waves amplified by the first and second amplifying sections, respectively, with a DC voltage outputted from a variable resistor to provide a superimposed signal; anda video amplifying section for amplifying said superimposed video signal and outputting said amplified superimposed video signal to a CRT.