Stylus power management using motion and orientation sensing

摘要

A system including an active stylus and a mobile computing device where an electronic signal emitted by the tip of the stylus that the mobile computing device uses to locate the tip is turned on and off when the stylus is not being used to save power. Whether the stylus is being used is determined based on an orientation of the stylus in comparison to an orientation of an electronic writing surface of the computing device. Difference in barometric air pressure or altitude between the stylus and mobile computing device may also be used to turn the tip signal on and off.

主权项

1. An active stylus configured for use with an electronic device, the active stylus comprising:
a processor; an accelerometer; a tip including a sensor, the sensor configured to detect contact between the tip and a surface of a touch screen of the electronic device; a radio frequency (RF) transmitter coupled to the tip configured to emit a modulated signal to be used by the electronic device to identify a location of the tip on the surface; a memory including instruction operable to be executed by the processor to cause the stylus to:
determine when the tip is in contact with the surface;determine when the tip is not in contact with the surface;determine a first orientation of the active stylus based on first data from the accelerometer from when the tip is in contact with the surface;determine a second orientation of the active stylus based on second data from the accelerometer from when the tip is not in contact with the surface;determine a first difference between the first orientation and the second orientation;determine that the first difference lies outside of a threshold range;deactivate the RF transmitter coupled to the tip based on the first difference lying outside the threshold range;determine that the tip is not in contact with the surface after the RF transmitter is deactivated;determine a third orientation of the active stylus based on third data from the accelerometer from when the tip is not in contact with the surface after the RF transmitter is deactivated;determine a second difference between the first orientation and the third orientation;determine that the second difference is within the threshold range; andreactivate the RF transmitter coupled to the tip based on the second difference being within the threshold range.