US Patent 10101828 Pen wake up on screen detect

A stylus that receives a signal transmitted by a digitizer and processes the received signal to control a state of the stylus is described. In implementations, a detector circuit in the stylus detects a signal emitted from a transmitter of the digitizer and toggles a state of the stylus between multiple states supported by the stylus. In implementations, the state of the stylus toggles between the multiple states in dependence upon a peak voltage associated with the detected signal. The stylus can also or instead be implemented to toggle a state of the stylus between the multiple states in dependence upon a relative proximity of the stylus to a digitizer. Different battery usage and conservation modes can be implemented in dependence upon a state of the stylus.