Apparatus for measuring the clearance of recording transducer, and a recorder using the apparatus, and a method of controlling the recorder
US5153785A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1989 |
| Grant date | Oct 6, 1992 |
| Priority date | — |
| Expiry date | Sep 15, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0925
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus for measuring the clearance between a recording transducer and a recording medium, which includes at least a conductive layer or conductive section, comprises a field electron emission electrode section disposed on the recording transducer, a voltage source for applying a voltage, which is greater at least in its peak value than the work functions of the electrode section and the conductive layer or conductive section of the recording medium, between the electrode section and the conductive layer or conductive section of the recording medium, a current measuring device for measuring the current flowing from the voltage source to the electrode section and the conductive layer or conductive section of the recording medium, and a computation processor for calculating the distance between the electrode section and the recording medium from the value of current measured by the current measuring device. A recording apparatus having the recording transducer clearance measuring apparatus is designed to support the recording transducer, which records and reproduces data on the recording medium, with a recording transducer supporting device through an advance/retract mechanism a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.