Patent ID: 6137245
Filing Date: 2000-10-24
Classification: G09G,H04N

Abstract:
A circuit for generating a control grid voltage for a CRT, comprising:a high-voltage source for supplying a high reference voltage, the high-voltage source being coupled to the ground through a low-impedance path;a low-voltage source for supplying a low reference voltage;an amplifier circuit, coupled between the high-voltage source and the low-voltage source and biased by the high reference voltage and the low reference voltage, for receiving an input signal and generating the control grid voltage responsive to the input signal, the amplifier circuit being constructed and arranged to discharge to an off state through the low-impedance path coupled between the high-voltage source and the ground and arranged such that the control grid voltage is driven to be the low reference voltage to cut off an electron beam of the CRT when the CRT is powered off;and a transistor coupled between a resistive network, said resistive network coupled to said amplifier circuit, and the ground and controlled by a pulse-width-modulation signal controlling the on/off states of the transistor for adjusted the input voltage generated at the junction of the resistive network.