Method of inspecting magnetic disk surface
US4789238A · kind A · utility
7Cited by
3References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 4, 1987 |
| Grant date | Dec 6, 1988 |
| Priority date | — |
| Expiry date | May 4, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9506
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a method of inspecting a magnetic disk surface, a magnetic disk web is exposed to a light beam, information on the condition of reflection of the light beam by the magnetic disk web or passing of the light beam through the magnetic disk web is detected, and the condition of surface defects of a magnetic disk is judged based on results obtained by the detected information. The judgement is carried out based on the results at a portion of the magnetic disk web outside of a non-use region of the magnetic disk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.