Coordinate input system and input implement used in the system
US5134689A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1988 |
| Grant date | Jul 28, 1992 |
| Priority date | — |
| Expiry date | Aug 24, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/03545
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A coordinate input system has a tablet composed of an X-direction loop coil assembly and a Y-direction loop coil assembly, and an input pen having a tuning circuit the tuning frequency of which is variable about a predetermined frequency. The system has a coordinate detecting function for detecting the X- and Y-coordinate values of position input by the input pen, and a phase detecting function for detecting the change in the tuning frequency of the tuning circuit as a change in the phase with respect to the phase of the predetermined tuning frequency. Information concerning the detected coordinate point, e.g., spread of the coordinate point proportional to the pressure at which the pen is pressed onto the tablet, is computed in accordance with the amount of change in the phase detected by the phase detecting function.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.