Optical sensor and optical apparatus using the same
US5663796A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 1996 |
| Grant date | Sep 2, 1997 |
| Priority date | — |
| Expiry date | Mar 11, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/254
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In an optical apparatus utilizing moire fringes to inspect surface irregularities of a test object, a single light beam forms a light beam network in an optical sensor (28) such that the test object can be two-dimensionally detected, thereby preventing the test object from abnormally approaching a moire grating (12). The light beam is reflected between a pair of mirrors (50, 52) a plurality of times within an identical plane and then the optical sensor (28) detects the intensity of the light beam. The optical sensor (28) is disposed such that the light beam network is positioned directly below the moire grating (12). Accordingly, a test object (2) abnormally approaching the moire grating (12) can be two-dimensionally detected by the light beam network, thereby improving the accuracy in detection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.