Multipoint touch surface controller
AssigneeApple Inc.
InventorsSteven P. HOTELLING, Christoph H. KRAH, Brian Q. HUPPI
Life of this patent
Estimating the term…
Abstract
A multipoint touch surface controller is disclosed herein. The controller includes an integrated circuit including output circuitry for driving a capacitive multi-touch sensor and input circuitry for reading the sensor. Also disclosed herein are various noise rejection and dynamic range enhancement techniques that permit the controller to be used with various sensors in various conditions without reconfiguring hardware.
Claims21
(canceled)
A method for demodulating one or more capacitive coupling signals associated with an image of touch, the method comprising:
- receiving, at a demodulator circuit, a first signal associated with a capacitive coupling between one or more drive electrodes and one or more sense electrodes of a touch surface during a first time period, wherein the one or more drive electrodes are driven with a first waveform during the first time period;
- performing a first operation associated with the first signal and a first demodulation waveform, wherein the first demodulation waveform is determined based on one or more characteristics associated with the first signal;
- generating a first demodulated signal based on performing the first operation;
- and
- determining an image of touch using the first demodulated signal.
A controller for a touch surface, the controller comprising:
- output circuitry configured to generate drive waveforms for one or more drive electrodes on the touch surface, the drive waveforms including a first periodic waveform having a first predetermined frequency;
- input circuitry operatively connected to one or more sense electrodes;
- a demodulator circuit coupled to the input circuitry;
- and
- one or more processors configured to:
- receive, at the demodulator circuit, a first signal, the first signal associated with a capacitive coupling between the one or more drive electrodes and the one or more sense electrodes on the touch surface during a first time period, wherein the one or more drive electrodes are driven with the first periodic waveform during the first time period;
- perform a first operation associated with the first signal and a first demodulation waveform, wherein the first demodulation waveform is determined based on one or more characteristics associated with the first signal;
- generate a first demodulated signal based on performing the first operation;
- and
- determine an image of touch using the first demodulated signal.
A computer-implemented method for controlling a touch surface, the method comprising:
- receiving, at a demodulator circuit, a first signal, the first signal associated with a capacitive coupling between one or more drive electrodes and one or more sense electrodes of a touch surface during a first time period, wherein the one or more drive electrodes are driven with a first waveform during the first time period;
- performing a first operation associated with the first signal and a first demodulation waveform, wherein the first demodulation waveform is determined based on one or more characteristics associated with the first signal;
- generating a first demodulated signal based on performing the first operation;
- and
- determining an image of touch using the first demodulated signal.
Dependencies are inferred from the claim text.