Process and apparatus for controlled laser texturing of magnetic recording disk
US5586040A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 1995 |
| Grant date | Dec 17, 1996 |
| Priority date | — |
| Expiry date | Apr 11, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B33/10
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Controlled laser texturing of a magnetic recording disk is accomplished by use of a textured test band on the disk and an analyzing laser system to provide feedback to the texturing laser. The analyzing laser system determines, from diffracted laser light, the average height of the laser-induced bumps formed in the test band by the texturing laser. The analyzing laser beam is directed to the substrate surface and overlaps a group of individual bumps formed in a repetitive pattern. A scanning linear photodector array receives light diffracted from the surface. The digitized output of the array is the angular distribution of diffracted light intensities and is used to compute the average height of the bumps in the test band. The disk is then translated radially so that the texturing laser is aligned with the region of the disk where the textured landing zone is to be placed. Then, in response to the computed value of average bump height in the test band, a correction signal or signals is output to modify one or more parameters of the texturing laser so that the texturing laser can form bumps of the correct average height in the textured landing zone.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.