Patent · US Expired

Position detecting apparatus

US5028745A · kind A · utility

101Cited by
5References
44Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 28, 1989
Grant dateJul 2, 1991
Priority date
Expiry dateSep 28, 2009

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F3/03545
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

The position of an implement is determined relative to a tablet including a tuned circuit with a resonant frequency including coils arranged in two coordinate directions. Coils of the tablet are sequentially excited with AC energy having approximately the same frequency as the resonant frequency. The tuned circuit interacts with the AC energy to change the AC current flowing in coils of the tablet as a function of the implement position so the greatest changes in the AC current are in coils of the tablet closest to the implement. Detected values of changes in current as a function of coil position are interpolated to indicate the implement position.

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