Magneto-optical recording/reproducing system having an electromagnetic actuator
US5305294A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1993 |
| Grant date | Apr 19, 1994 |
| Priority date | — |
| Expiry date | Mar 30, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10576
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Magneto-optical disk recording and reproducing devices and actuators and distance detectors for use therewith are disclosed. The mageneto-optical disk device comprises, in addition to the usual elements, a bimorph type actuator or an electromagnetic actuator for driving the magnetic head of the magneto-optical disk device. The bimorph actuator has a metallic shim whose width varies with respect to the longitudinal distance inversely porportional to the normal function of the first or the second free natural vibration mode. Alternatively, the bimorph type actuator have a recess formed on a bimorph element to expose a piezoelectric crystal which outputs a voltage corresponding to the acceleration of the vibration of the actuator; the driver circuit of the actuator reduces the driving voltage when the frequency of the voltage generated at the recess comes into the neighborhood of a higher resonance frequency of the actuator. The optical distance detector comprises a light-emitting diode and a pair of photodiodes which detects the amount of light incident thereon after being reflected at a surface of an object the distance to which is measured. The geometric parameters of the photodiod…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.