Active stylus force sensing mechanism for generating a wakeup interrupt to the controller
US9081569B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 2012 |
| Grant date | Jul 14, 2015 |
| Priority date | — |
| Expiry date | Jun 14, 2033 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D10/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An active stylus having a control circuit configured to wake up the stylus from a sleep mode to an active mode in response to pressure applied to a tip of the stylus. The stylus includes a force sensor electrically coupled to a power source, an operational amplifier, and a voltage level comparator, the voltage level comparator configured to output a digital wake up interrupt signal when pressure is applied to the tip when the control circuit is in the sleep mode. The operational amplifier is configured to provide an analog signal representative of varying pressure on the tip. This signal is processed by the control circuit such that the stylus goes into the sleep mode after a specified period of time following cessation of variations in the analog signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.