Apparatus for and method of verifying etching of optical servo information on magnetic media
US5334849A · kind A · utility
14Cited by
9References
44Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 10, 1992 |
| Grant date | Aug 2, 1994 |
| Priority date | — |
| Expiry date | Jun 10, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B33/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for etching a point on the surface of a magnetic medium to reduce the reflectivity of the point and for verifying that proper etching occurred. A light source provides a collimated incident beam of light. The incident beam is focused to a point on the medium and a portion of the beam is reflected. The reflected beam is separated from the incident beam and the intensity of the reflected beam is measured. The measured intensity is compared to a threshold value and verification is indicated if the measured intensity exceeds the threshold value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.