Method and apparatus for detecting surface flaws
US5835220A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1995 |
| Grant date | Nov 10, 1998 |
| Priority date | — |
| Expiry date | Oct 27, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J4/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for detecting a surface flaw which includes the steps of (i) irradiating polarized light to a surface of a sample to be inspected and determining ellipso-parameters (.PSI., .DELTA.) of reflected light from the surface of the sample; (ii) irradiating light to a same position as irradiated by the polarized light and determining the intensity (I) of reflected light from the surface of the sample; and (iii) determining a type and grade of a flaw on the surface of the sample based on the ellipso-parameters (.PSI.,.DELTA.) and the reflected light intensity (I). A surface flaw detecting apparatus includes (i) a first measuring device for irradiating polarized light to a surface to be inspected and measuring ellipso-parameters (.PSI.,.DELTA.) of reflected light from the surface; (ii) a second measuring device for irradiating light to a same position as irradiated by the polarized light and measuring the intensity (I) of reflected light from that position; and (iii) an output device for outputting a three-dimensional coordinate position of .PSI., .DELTA., I representing the reflected light from the surface, while sorting the position into a preset zone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.