Electron beam detecting device
US9632117B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 2013 |
| Grant date | Apr 25, 2017 |
| Priority date | — |
| Expiry date | Feb 25, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J33/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electron beam detecting device detects a state of an electron beam radiated by an electron beam radiation device. A plurality of wire electrodes, which are conductors, are disposed corresponding to a plurality of filaments, the wire electrodes being electrically insulated from each other, in the area in which the electron beams are radiated. The electrical current flowing through each of the wire electrodes is measured by an electric current measuring instrument (measuring unit). A CPU (determining unit) determines the radiation level of the electron beams by receiving a signal output by the electric current measuring instrument. The CPU judges that when the measuring instrument measures a decrease of the current value, an abnormal condition exists in the filament corresponding to the conductor with the lower current value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.