Patent · US Expired

Voice coil motor with linearized force constant

US4908816A · kind A · utility

19Cited by
8References
1Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 20, 1988
Grant dateMar 13, 1990
Priority date
Expiry dateDec 20, 2008

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11B7/08582
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A linear motor with uniform force constant across the full stroke length achieved by varying the width of the air gap face area of the permanent magnet such that the width is reduced towards the center of the magnet in relation to the widths at the ends thereof to compensate for reducing field strength at the magnet ends caused by fringing effects on the field.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.