Apparatus for converting the position of a manually operated instrument into an electrical signal
US4039747A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 5, 1976 |
| Grant date | Aug 2, 1977 |
| Priority date | — |
| Expiry date | Feb 5, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0446
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An improved apparatus capable of converting the position of a pen-type sensor relative to the surface of a writing table into an electrical signal representative of such position and which may be utilized for control, data input or transmission purposes. The writing table includes two sets of independent, spaced-apart conducting wires which form a grid throughout the writing area. The conducting wires are individually and discretely pulsed sequentially to generate a time varying electrostatic field adjacent to the writing table that can be sensed by the sensor. The signal sensed by the sensor and the signals used to drive the time-varying electrostatic field are electronically processed and converted into electrical signals representing the position of the sensor relative to the writing table.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.