Dual collector optical flaw detector
US4597665A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1984 |
| Grant date | Jul 1, 1986 |
| Priority date | — |
| Expiry date | May 14, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/112
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A flaw detector for optically transmissive surfaces having a first light collector above the surface and a second light collector below the surface. A scanning light beam is directed into the first light collector through a beam entrance aperture and only light scattered from the surface is collected. Light specularly reflected from the surface exits the collector through the beam entrance aperture. Similarly, light passing through the surface enters the second collector, but the axial beam component is dumped through an opening in the second collector, while only diffracted light is collected. Preferably, two-stage light collectors are used with the first stage admitting the beam and generating a scattered or diffracted beam component, with the second stage admitting the scattered or diffracted beam component and integrating the component over a collection surface and sampling the integrated portion at a photoelectric detector. An electrical output signal from the detector may be displayed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.