Input device with two input signal generating means having a power state where one input means is powered down and the other input means is cycled between a powered up state and a powered down state
US6611921B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 26, 2001 |
| Grant date | Aug 26, 2003 |
| Priority date | — |
| Expiry date | Nov 26, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D10/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Power management is provided in a user operated data input device utilizing proximity sensing and switching between three or more power states. Capacitive proximity sensing may be carried out by detecting a relative change in the capacitance of a “scoop” capacitor formed by a conductor and a surrounding ground plane, wherein charge is transferred between the “scoop” capacitor and a relatively large “bucket” capacitor, a voltage of the bucket capacitor is applied to an input threshold switch, and a number of cycles of charge transfer required to reach the state transition is determined. Switching between the power states occurs based upon the presence or absence of input activity, and an operation instrumentality (e.g., a hand) in close proximity to or contact with the device. In an optical surface tracking cursor control device embodiment, switching to and from a BEACON state, which provides a reduced flash rate of a surface illuminating light source, is carried out based upon a detected presence or absence of a trackable surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.