Magneto-optical scanning device with small coil
US5307328A · kind A · utility
6Cited by
3References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1992 |
| Grant date | Apr 26, 1994 |
| Priority date | — |
| Expiry date | Sep 23, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10532
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A device for writing, reading or erasing a record carrier has a coil with a winding arranged between an objective lens and the record carrier. Optical radiation is focused to a spot, the converging beam passing through the coil opening. A core of a transparent material, having an index of refraction which significantly decreases vergence of the focused beam, is placed in the winding opening. As a result the diameter of the coil can be reduced, and permit increase of the generated magnetic field.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.