Beam irradiation device
US8345268B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 2010 |
| Grant date | Jan 1, 2013 |
| Priority date | — |
| Expiry date | Aug 30, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/42
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A beam irradiation device includes a photodetector which receives servo light and outputs a detection signal depending on a light receiving position of the servo light, and a signal processing section which obtains the light receiving position based on the detection signal. In the above arrangement, the signal processing section has an A/D conversion circuit which converts the detection signal into a digital signal, and an error signal adjusting circuit which converts an error component signal to be outputted from the photodetector when the photodetector is not irradiated by the servo light, into a signal within a processable range of the A/D conversion circuit, and supplies the converted signal to the A/D conversion circuit. A first digital signal derived from the detection signal is corrected with a second digital signal derived from the error component signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.