Digitizer having flat tablet with magnetic shield plate
US4956526A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jul 18, 1989 |
| Grant date | Sep 11, 1990 |
| Priority date | — |
| Expiry date | Jul 18, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2203/04107
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A digitizer for determining coordinate value of a point designated on a given two-dimensional coordinate plane. A pointing instrument is manually operable to designate a point on the given two-dimensional coordinate plane of a tablet. The tablet includes a flat sensor defining the given two-dimensional coordinate plane and operative for transmitting magnetic signal between the flat sensor and the pointing instrument disposed thereon to detect the designated point to thereby produce a detection signal, and a shielding plate disposed under the flat sensor to magnetically shield the flat sensor. The shielding plate is composed of silicon steel containing 4.0 to 7.0 weight % of silicon. A processing circuit is connected to the flat sensor for processing the detection signal to determine the coordinate value of the designated point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.