Opto-electronic apparatus for inscribing and/or reading recording tracks by means of a radiation beam
US4561081A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1981 |
| Grant date | Dec 24, 1985 |
| Priority date | — |
| Expiry date | Oct 21, 2001 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16C2370/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An opto-electronic apparatus for inscribing and/or reading recording tracks on a record carrier by means of a radiation beam comprises an objective mounted in an objective holder. The objective holder is supported in a frame by bearing arrangement for movement in accordance with a number of desired degrees of freedom and the apparatus includes electromagnetic actuator means for driving the objective holder in accordance with the desired directions of movement. The bearing arrangement of the objective holder on the frame comprises electromagnetic bearing means for counteracting movements in accordance with at least one undesired degree of freedom. An objective-position measuring device supplies a positional error signal which represents the deviation of the objective holder in accordance with the undesired degree of freedom relative to the frame and which is utilized by a levitation control circuit which counteracts movements of the objective holder relative to the frame in accordance with the undesired degree of freedom by means of electromagnetic levitation forces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.