Non-contact displacement detecting device using optical astigmatism
US8247786B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 2009 |
| Grant date | Aug 21, 2012 |
| Priority date | — |
| Expiry date | Feb 24, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A displacement detecting device includes a non-contact sensor having a light source, an objective lens focusing output light from the light source onto a measurement surface, and a light receiving element detecting displacement information based on a focal length of the objective lens by using reflected light from the measurement surface; a control unit adjusting the focal length based on the displacement information; a displacement-amount measuring unit having a linear scale attached to the objective lens with a link member therebetween and measuring an amount of displacement of the linear scale when the focal length is adjusted. A light adjustment member is disposed between the light source and the objective lens or between the objective lens and the light receiving element and has an aperture section transmitting the output and/or reflected light therethrough and a light blocking section that blocks a specific light component of the output and/or reflected light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.