STYLUS AND TOUCH INPUT SYSTEM
One variation of a system for tracking stylus inputs on a touch sensor surface includes: a touch sensor surface, and a touch sensor arranged under the touch sensor surface. The touch sensor includes a substrate and a set of drive and sense electrode pairs. The system further includes an excitation inductor arranged under the touch sensor surface and a stylus. The stylus includes: a body; a conductive stylus tip; and a stylus inductor configured to inductively couple to the excitation inductor to induce a voltage at the conductive stylus tip. The system includes a controller configured to: drive the excitation inductor with an alternating voltage signal; detect a set of self-capacitance values across the substrate; and detect a stylus location of a stylus input for the conductive stylus tip on the touch sensor surface based on the set of self-capacitance values and the second set of self-capacitance values.
1 . A system for tracking stylus inputs on a touch sensor surface comprising:
a touch sensor surface;
a touch sensor arranged under the touch sensor surface and comprising:
a substrate;
a first array of drive electrodes arranged on the substrate; and
a second array of sense electrodes arranged on the substrate and paired with the first array of drive electrodes;
a first excitation inductor arranged under the touch sensor surface; and
a stylus comprising:
a body;
a conductive stylus tip arranged on a distal end of the body; and
a first stylus inductor arranged in the body and configured to inductively couple to the first excitation inductor to induce a first voltage at the conductive stylus tip.
1 . The system of claim 1 , further comprising a controller configured to:
during a first touch segment of a first scan cycle:
drive the first array of drive electrodes;
detect a set of mutual-capacitance values across the second array of sense electrodes; and
detect a touch location of a non-stylus input on the touch sensor surface based on the set of mutual-capacitance values; and
during a first stylus segment of the first scan cycle:
drive the first excitation inductor with an alternating voltage signal;
detect a first set of self-capacitance values across the first array of drive electrodes;
detect a second set of self-capacitance values across the second array of sense electrodes; and
detect a first stylus location of a stylus input for the conductive stylus tip on the touch sensor surface based on the first set of self-capacitance values and the second set of self-capacitance values.