Apparatus for suppressing field radiation from display device.

摘要

In order to eliminate such a possibility that field radiation in a VDT exerts a bad influence on the human body, field radiation from a front surface of a cathode ray tube is reduced. A degaussing coil (3) arranged in proximity to the peripheral edge of a front surface (2) of a cathode ray tube (1) is so advantageously employed that this degaussing coil (3) is supplied with a voltage which is reverse in polarity to an electric field (12) radiated from the front surface (2) of the cathode ray tube (1). The voltage of reverse polarity is provided by an output signal (18) obtained from an output signal (16) of a horizontal deflection circuit (15) by a flyback transformer (17) and/or a voltage obtained by phase-inverting an anode voltage fluctuating in vertical synchronization. After a degaussing operation is completed, relay contacts (7, 8) are opened on the basis of a timer-controlled relay switch (9), thereby completely cutting connection between the degaussing coil (3) and a degaussing power source (4) generating an alternating current which is supplied to the degaussing coil (3) for the degaussing operation. <IMAGE>