Position detecting device
US4988837A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1990 |
| Grant date | Jan 29, 1991 |
| Priority date | — |
| Expiry date | Apr 30, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/046
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The position on a surface of an implement including a tuned circuit with a predetermined resonant frequency is determined and displayed by an apparatus having a housing including the surface. A tablet in the housing includes coils arranged in two coordinate directions parallel to the surface. The coils are 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 the coils as a function of the implement on the tablet. An electronic two-coordinate direction display in the housing configured as a plate is superposed with and lies in a plane parallel to the tablet and the surface. The display responds to the change in AC current resulting from the interaction between the AC energy and the tuned circuit to indicate the position of the implement on the surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.