Magneto-optical recording and reproducing disk device having a bimorph type actuator with specific structures for mounting a magnetic head in opposing to the surface of the disk
US5247493A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 1989 |
| Grant date | Sep 21, 1993 |
| Priority date | — |
| Expiry date | Apr 5, 2009 |
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 magneto-optical disk device includes 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 having a width that varies with respect to the longitudinal distance in inverse proportion to the normal function of the first or the second free natural vibration mode. Alternatively, the bimorph type actuator has a recess formed on a bimorph element to expose a piezoelectric portion 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 the light is reflected from a surface of an object the distance to which is measured. The geometric parameters of the photodiodes are selected such th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.