Patent ID: 6288690
Filing Date: 2001-09-11
Classification: G09G,H04N

Abstract:
A video control circuit for a video display device, comprising:a preamplifing section for controlling and preamplifying gains and contrast of color video signals from a computer system;a video output section for amplifying an output signal of the preamplifying section and outputting the amplified output signal to a cathode ray tube;a first variable resistor for controlling contrast and providing an output signal;a second variable resistor for controlling brightness and providing an output signal;converting means for receiving the output signals from said first and second variable resistors and a bias/gain control input signal, and for converting the received signals in an inter interface control (I.sup.2 C) manner so as to obtain converted data for controlling contrast, brightness, gain and bias, and so as to provide a clock signal;I.sup.2 C data process and pulse width modulation signal generation means connected to said converting means and responsive to the converted data and the clock signal therefrom for generating pulse width modulated (PWM) signals for controlling contrast, brightness, bias and gain; andrectification means connected to said I.sup.2 C data process and pulse width modulation signal generation means for generating a contrast control signal, a brightness control signal, a gain control signal and a cutoff voltage by rectifying the PWM signals generated by said I.sup.2 C data process and pulse width modulation signal generation means; anda cutoff control section connected to said rectification means for receiving said brightness control signal and said cutoff voltage, and responsive thereto for generating a bias voltage and applying said bias voltage to said video display device.