Patent ID: 6504534
Filing Date: 2003-01-07
Classification: G06F,G09G,H04N,Y02D

Abstract:
A CRT display unit adapted to be connected to a central unit which generates a synchronizing signal and a video signal for displaying an image of said video signal on the CRT display unit, said CRT display unit comprising:a) a power supply circuit including: 1) a main power supply; and 2) an auxiliary power supply; b) a power circuit driven by said main power supply independently of said auxiliary supply, said power circuit including: 1) a high voltage circuit; 2) a deflection circuit; and 3) a video circuit; c) a synchronous processing circuit for processing said synchronizing signal output from said central unit and supplying a processed synchronizing signal to said high voltage circuit and said deflection circuit; d) a video input processing circuit including: 1) a video signal detector for detecting at least one of the presence and absence of said video signal output from said central unit, for processing said video signal and supplying a processed video signal to said video circuit; e) a CRT including: 1) an anode being supplied with a high dc voltage from said high voltage circuit; 2) a deflection yoke being supplied with a deflecting current from said deflection circuit; 3) a cathode being supplied with a cathode drive signal from said video circuit; and 4) a heater being supplied with a current from said auxiliary power supply independently of said main power supply; f) a main power supply controller for controlling said main power supply to turn on and turn off said power circuit upon detection of the presence and absence, respectively, of said processed video signal output by said video signal detector; g) a first timer for timing at least a predetermined period of time starting when a turn off operation of said power circuit is executed by said main power supply controller and continuing timing until said predetermined period of time has elapsed; and h) an auxiliary power supply controller for controlling said auxiliary power supply to turn off said heater after a lapse of said predetermined period of time which is previously set in said first timer.