Dual mode touchpad with a low power mode using a proximity detection mode

摘要

A system includes a touchpad sensor array, a touch circuit, and a proximity circuit. The touch circuit executes a touch mode configured to track the position of a user or conductive object on the touchpad sensor array by detecting a change in an electrical property of the touchpad. The proximity circuit executes a proximity detection mode configured to track the position of a user or conductive object near or proximate to the touchpad sensor array by detecting a change in an electrical property of the touchpad. The system is configured to switch from the touch mode to the proximity detection mode after a predetermined period of inactivity, where the proximity detection mode can operate at one or more reduced polling rates, resulting in a reduced overall power dissipation. The system is configured to switch back to the touch mode when activity is detected by the proximity circuit.

主权项

1. A system comprising:
a touch-based interface; a proximity circuit electronically coupled to the touch-based interface and configured to detect a change in an electrical property of the touch-based interface to detect a user adjacent to the touch-based interface but not touching the touch-based interface; and a touch circuit electronically coupled to the touch-based interface and configured to detect a change in an electrical property of the touch-based interface to detect a touch on the touch-based interface; wherein if the proximity circuit is electronically monitoring the touch-based interface, the touch circuit is electronically decoupled from the touch-based interface, and if the touch circuit is electronically monitoring the touch-based interface, the proximity circuit is electronically decoupled from the touch-based interface; wherein if the touch circuit is configured to monitor the touch-based interface for a touch mode of operation, after a first inactivity time of the touch-based interface, the proximity circuit is configured to monitor the touch-based interface for a proximity mode of operation and the touch circuit is electronically decoupled from the touch-based interface, and wherein if the proximity circuit is configured to monitor the touch-based interface, after a second inactivity time of the touch-based interface, a polling rate of the proximity circuit is reduced from a first polling rate to a second polling rate.