Patent ID: 9632117
Date: 2017-04-25
CPC Classifications: G01R,G21K,H01J

Claim:
1. An electron beam detecting device, by which a state of an electron beam radiated by an electron beam radiation device is detected, the electron beam detecting device comprising: a plurality of conductors disposed such that each one of the plurality of conductors is arranged corresponding to each one of a plurality of filaments, the plurality of filaments are provided in the electron beam radiation device to radiate thermal electrons, the conductors being electrically insulated from each other, in the area in which the electron beams are radiated; a plurality of measuring units, each measuring unit corresponding to one conductor, the plurality of measuring units measuring the current value flowing through each one of the conductors; and a determining unit determining the radiation level of the electron beams by receiving a signal output by each of the plurality of measuring units, the determining unit judging that when one of the measuring units measures a decrease in the electrical current value, an abnormal condition exists in the filament corresponding to the conductor in which the lower current value is detected.