Digitizer stylus with pressure transducer
USRE34095E · kind E · reissue
Assignee
Inventors
Key dates
| Filing date | Sep 17, 1990 |
| Grant date | Oct 13, 1992 |
| Priority date | — |
| Expiry date | Sep 17, 2010 |
Classification
- Technology area (CPC —)General
Abstract
A stylus switch is activated automatically when the tip of the stylus is pressed against a digitizer tablet with sufficent force. The pressure switch inlcudes a transducer in the form of an ink layer having electrical resistance which varies as a function of the pressure applied thereon. Electrodes of conductive ink contact the ink layer of the transducer, providing a circuit element including a variable resistance. The current which flows between the two conductive ink electrodes varies as a function of the force with which the stylus tip is pressed against the data tablet, thus providing an analog output which can be detected as a function of pressure or which can be detected to determine when the pressing force exceeds a predetermined value. Processing of the data representing the coordinates of the stylus tip is enabled only when the tip is being pressed with at least a predetermined force, i.e. the amount of force applied by a stylus user during writing. The ink layers of the electrodes and transducer, as well as the stylus anode, are applied on a single piece of flexible plastic film which is wrapped around a central assembly and inside a coaxial barrel. A collapsible dome of…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.