Abstract: A display device capable of removing a defocused beam spot on the focusing screen by obtaining the fluctuation of a focusing voltage following the fluctuation of a high-tension voltage. There is applied a DC voltage of a predetermined high-tension voltage. Also, there is supplied a dynamic focus (DF) correction waveform such as a parabolic waveform voltage or the like matched with horizontal and vertical deflections or the like, for dynamically controlling the focusing in accordance with the shape of the tubular surface of a cathode-ray tube or the like. Further, there is supplied a peak focus (PF) correction waveform voltage corresponding to the fluctuation of the high-tension voltage. The DF correction waveform and the PF correction waveform are added by an adder. An added signal from the adder is amplified by an amplifier to 600 to 800 Vp-p, for example.

Abstract: Discharge current limiting resistors are provided in respective high-voltage supply lines for distributing high voltages produced by a high-voltage distributor to the anodes of respective CRTs. As a result, a discharge current coming from a high-voltage capacitor that is part of a total discharge current flowing into a CRT where an abnormal discharge has occurred can be reduced to ½ of that in the conventional case and discharge currents coming from coating capacitances of the remaining CRTs that is another part of the total discharge current can be inhibited.