Surface inspection method and surface inspection device
US7477373B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2007 |
| Grant date | Jan 13, 2009 |
| Priority date | — |
| Expiry date | Mar 20, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/887
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A surface inspection method for projecting a laser beam to an inspection surface and for scanning and detecting foreign objects or the like on the inspection surface, comprising a step of being had a required number of detecting regions by a photodetector against a projecting site of the laser beam, a step of receiving a detection light at the photodetector so that a detection light intensity is varied between the detecting regions, a step of acquiring a required number of output signals with different detection light intensities on an inspection site, and a step of selecting an output signal which is an unsaturated output signal and has the highest value among the required number of output signals as a surface detection signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.