Stylus sensing system
US5117071A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1990 |
| Grant date | May 26, 1992 |
| Priority date | — |
| Expiry date | Oct 31, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2203/04106
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An improved finger touch and stylus detection system for use on the surface of a display device is disclosed. An overlay having horizontal and vertical transparent conductors is coupled to the other elements of the system through a bus having a minimum number of bus wires. A control processor issues command signals which selectively couples the transparent conductors to a capacitive measuring device and a radiative measuring device to determine finger and stylus position respectively. The improvements to the system include a radiative stylus having a spherical antenna which receives the overlay signal independent of the angle at which it is held. Further, a contact detecting mode has been added to eliminate spurious stylus positions measured between strokes, when the stylus is proximate to but not in contact with the overlay.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.