Patent attributes
A microcomputer 60 takes in voltages output from the sustaining voltage Vsus generation circuit 52, the addressing voltage Vadd generation circuit 53, and the standby voltage generating circuit 54 via A/D input ports 1 through 6 mounted on the microcomputer board, and performs examinations to judge whether abnormal values are detected about the voltages. If there is at least one abnormal value detected, the main power supply is set OFF and after a predetermined time the main power supply is set ON again to perform a reexamination. If the number of times when abnormal values about a certain voltage are detected reaches the number of abnormal value detections N, the main power supply is left OFF. The number of abnormal value detections N for the Vsamp, the Vset, the Ve or the Vscan, is set larger than the number of abnormal value detections set for the Vsus or the Vadd.
