External magnetic field correction device and CRT display device

摘要

An external magnetic field correction device capable of preventing malfunctions of the external magnetic field correction device due to operation of a degaussing circuit by judging that an abnormality has occurred when an output of an external magnet.ic field detector is not less than a predetermined value and interrupting offset adjustment process accordingly, and that is capable of limiting irregularities of offset current in operational current of the magnetic field correction device to predetermined value or less by adjusting an offset value as to make correction current to be supplied to an external magnetic field correction coil when an external magnetic field around a CRT is zero to a regular value or less.