Noncontact optical gauging system
US4299491A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1979 |
| Grant date | Nov 10, 1981 |
| Priority date | — |
| Expiry date | Dec 11, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/24
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A laser beam is focused to a spot on the surface of an object whose contour is to be measured. The spot is projected from the surface onto a detector by a reciprocating mirror which scans the spot across the detector. The detector produces two output signals consisting of sequential pulses at the frequency scan. The relative duration of these pulses or duty cycle reflects the change in contour dimension with respect to the scan centerline or mid point that corresponds to the base or zero dimension of the contour surface. The duty cycle is utilized to compute the change in contour dimension and to move the optics in such a way as to allow the spot to be continually scanned across the detector. The movement of the optics is made whenever there is a certain contour dimension change and by correlating the movement in the position of the optics and the instantaneous computed contour change reflected in the scan, the actual contour dimension is obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.