Display apparatus for displaying pictures virtually instantaneously

A display apparatus for displaying pictures comprising:

• a cathode ray tube having a dispenser cathode wherein a cathode material is filled in pores of a porous body and a porous heater is directly connected to said cathode material;
• a voltage generator which produces a first voltage for driving said heater;
• means for supplying a video signal to said cathode;
• deflection means for deflecting horizontally and vertically an electron beam generated from said cathode to produce a raster by scanning the fluorescent surface of said cathode ray tube;
• and
• a flyback transformer for generating a second voltage so as to be supplied to an anode and one or more grids of said cathode ray tube using a horizontal deflection output signal supplied from said deflection means, wherein said voltage generator comprises a heater transformer for transforming the second voltage of said flyback transformer into a rating voltage or a rating current for driving said heater, said heater transformer comprising at least one primary winding coil to which the second voltage of said flyback transformer is applied and at least two independent secondary winding coils, all of which have the same number of coil windings.