Optical surface detection for magnetic disks
US5661559A · kind A · utility
23Cited by
3References
28Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1996 |
| Grant date | Aug 26, 1997 |
| Priority date | — |
| Expiry date | Mar 14, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/88
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An automatic surface inspection apparatus comprises a light source that provides a coherent light beam that is spit and then recombined in a prism to generate an interference pattern. A cylindrical lens projects the interference pattern onto the surface of a disk as a line of light. A linear detection array converts the reflected line of light into an electrical signal that has a magnitude which varies dependent upon the reflected light intensity. Defects present on the surface of the disk cause variations in the reflected light intensity manifested as differences in the electrical signal output by the detection array.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.