Optical sensor with an elliptical illumination spot
US5719840A · kind A · utility
21Cited by
3References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 30, 1996 |
| Grant date | Feb 17, 1998 |
| Priority date | — |
| Expiry date | Dec 30, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/1378
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical sensor which provides a focused elliptical illumination spot. The instrument includes a light source which provides a light beam that is directed through a cylindrical lens. The cylindrical lens focuses the light beam normally on a disk surface as an elliptical illumination spot with a major axis along a tracking direction and a minor axis along a scanning direction. Light scattered by the disk is then detected by a detector and processed to detect defects on the disk surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.