Coordinates input apparatus
US4999461A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 1989 |
| Grant date | Mar 12, 1991 |
| Priority date | — |
| Expiry date | May 19, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/046
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A coordinates input apparatus has a tablet including X- and Y-direction position detecting portions having a multiplicity of loop coils arranged in parallel with one another in X- and Y-directions, respectively, the X- and Y-direction position detecting portions being superposed one on the other. The apparatus also has a position appointing device incorporating a tuning circuit capable of making resonance with electric wave produced from one of the loop coils. The loop coils are successively selected in a one-by-one fashion and an A.C. signal of a predetermined frequency is supplied to the thus selected loop coil. The electric wave causes a tuning of the tuning circuit in the position appointing device so that a voltage of a frequency substantially the same as the above-mentioned predetermined frequency is generated in the loop coil which is near the position appointing device. The position appointed by the position appointing device is therefore detected by sensing the induced voltage of a frequency substantially equal to the predetermined frequency of the A.C. voltage, through a processing by a suitable processing device. Since the position appointing device need not be connected…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.