LOW-COST RESISTIVE TABLET WITH TOUCH AND STYLUS FUNCTIONALITY

摘要

A data entry device with a resistive layer enables a user to enter data both by finger and stylus. The stylus is electrically connected to the device. An AC driver drives the layer with a time-varying voltage for capacitive finger detection. A DC driver drives the layer with a substantially constant voltage for resistive stylus detection. The AC driver is disabled when the capacitance of the stylus relative to ground is increased due to the user's hand holding the stylus.