Digitizer tablet having high permeability grid shield
US5357061A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 30, 1992 |
| Grant date | Oct 18, 1994 |
| Priority date | — |
| Expiry date | Apr 30, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/046
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A combined shield member and grid shield for a digitizer tablet having conductive grids on a flexible substrate comprising a sheet of a metal having a high magnetic permeability substantially the size of a square X-Y axis coordinate system of the digitizer tablet shielding the flexible substrate. Preferably, the metal has an initial permeability of at least 5,000. The metal can be a NiFe alloy having an initial permeability sufficiently high to qualify it as a .mu.-metal. Typically, the sheet of metal is a square sheet of substantially the size of a square X-Y axis coordinate system of the digitizer tablet and the flexible substrate has edge portions which extend beyond side edges of the sheet of metal and are wrapped around the side edges. An alternate embodiment employs the high permeability shield positioned between two rigid substrates carrying the grids and interconnects respectively. A conductive metal foil over the surface of the substrate corrects any signal errors introduced by the shield. The foil can also be grounded for electostatic shielding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.