Force sensing semiconductive touchpad
US6239790A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1999 |
| Grant date | May 29, 2001 |
| Priority date | — |
| Expiry date | Aug 17, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0488
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A touchpad assembly and method for providing a signal to a computer indicative of the location and applied pressure of an object touching the touchpad assembly is provided. The touchpad assembly includes X and Y position and pressure sensitive semiconductor resistance sensor layers. The X and Y sensors have a pair of spaced apart X and Y conductive traces running across opposite ends such that a resistance RX connects the pair of X traces and a resistance RY connects the pair of Y traces. The X and Y sensors come into contact at a contact point when an object asserts a pressure on the touchpad. The contact point is connected to each trace by a variable pressure resistance RZ associated with the X and Y sensors and variable position resistances of the X and Y resistances. First and second pair of timing capacitors are connected to respective ones of the pairs of X and Y traces. A microprocessor controls and monitors charging time of the capacitors to determine the position and asserted pressure of the object touching the touchpad.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.