Using spectral control in detecting touch input

摘要

Detecting a location of a touch input on a surface of a propagating medium is disclosed. A transmitter coupled to the propagating medium emits a signal. The signal is received using a receiver coupled to the propagating medium. The receiver is configured to receive the signal from the transmitter to at least in part detect the location of the touch input as indicated by an effect of the touch input on the signal. Spectral control of the signal is performed.

主权项

1. A system for detecting a location of a touch input on a surface of a propagating medium, including:
a transmitter coupled to the propagating medium and configured to emit a signal, wherein the signal has been allowed to freely propagate through the propagating medium in multiple directions to a plurality of receivers on a plurality axes of the propagating medium, wherein the propagating medium is a touch input medium made of at least one of the following: glass, plastic, metal, or semiconductor; a receiver coupled to the propagating medium, wherein the receiver is one of the plurality of receivers on the plurality axes of the propagating medium and the receiver is configured to receive a touch input affected version of the signal to at least in part detect the location of the touch input as indicated by an effect of the touch input on the signal; a signal generator configured to perform spectral control including by using a windowing function or an amplitude modulation to generate an intermediary signal that is modulated to a carrier frequency to generate the emitted signal and selecting the carrier frequency such that the emitted signal is an ultrasonic signal.