Method of grinding core blank for magnetic heads, using markers for determining grinding depth for nominal magnetic gap depth
US5305559A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 29, 1993 |
| Grant date | Apr 26, 1994 |
| Priority date | — |
| Expiry date | Apr 29, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/232
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of grinding a core blank which yields at least one head core each used for a magnetic head, each head core having an annular magnetic path having a magnetic gap, the core blank having a working surface that is to be opposed to a magnetic recording medium is disclosed. According to the present grinding method, at least one marker is formed by photolithography so that the marker(s) is/are embedded in the core blank. Each marker has two edges which are spaced from each other in a direction of width of the magnetic gap, by a first distance that continuously varies in a direction of depth of the magnetic gap, the two edges of each marker being located on the same side as viewed in the gap-width direction. During grinding of the core blank, the first distance between the two edges of each marker which is exposed on the working surface under grinding is measured, so as to determine a required residual depth of grinding which is to be further effected to establish a nominal depth dimension of the magnetic gap.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.