INPUT DEVICE INTERFERENCE DETERMINATION
First Claim
1. An interference determining circuit for a capacitive sensor device, said circuit comprising:
- an amplifier configured for receiving a reference voltage at a first input and for receiving a resulting signal at a second input, wherein the resulting signal is from a sensor electrode of said capacitive sensor device;
absolute differential circuitry coupled with an output of said amplifier and configured for outputting a difference signal, wherein said difference signal represents an absolute differential between currents utilized in said amplifier; and
comparator circuitry coupled with said absolute differential circuitry and configured for generating a non-linearity indication based on a comparison of said difference signal with at least one reference signal.
3 Assignments
0 Petitions
Accused Products
Abstract
An interference determining circuit for a capacitive sensor device comprises an amplifier, absolute differential circuitry, and comparator circuitry. The amplifier is configured for receiving a reference voltage at a first input and for receiving a resulting signal at a second input. The resulting signal is from a sensor electrode of the capacitive sensor device. The absolute differential circuitry is coupled with an output of the amplifier and configured for outputting a difference signal. The difference signal represents an absolute differential between currents utilized in the amplifier. The comparator circuitry is coupled with the absolute differential circuitry and configured for generating a non-linearity indication based on a comparison of the difference signal with at least one reference signal.
67 Citations
21 Claims
-
1. An interference determining circuit for a capacitive sensor device, said circuit comprising:
-
an amplifier configured for receiving a reference voltage at a first input and for receiving a resulting signal at a second input, wherein the resulting signal is from a sensor electrode of said capacitive sensor device; absolute differential circuitry coupled with an output of said amplifier and configured for outputting a difference signal, wherein said difference signal represents an absolute differential between currents utilized in said amplifier; and comparator circuitry coupled with said absolute differential circuitry and configured for generating a non-linearity indication based on a comparison of said difference signal with at least one reference signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method of interference determination in a capacitive sensor device, said method comprising:
-
measuring a resulting signal received from a receiver electrode of a capacitive sensor device, wherein said measuring is performed with an amplifier; determining a difference signal, wherein said difference signal represents an absolute differential between currents utilized in said amplifier during said measuring; and generating a non-linearity indication based upon a comparison of said difference signal with at least one reference signal. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
-
17. An input device comprising:
-
a sensor pattern including a transmitter electrode and a receiver electrode; a processing system coupled with said sensor pattern and configured to; drive a transmitter signal onto said transmitter electrode; receive a resulting signal from a receiver electrode with an amplifier of said processing system; output a difference signal, wherein said difference signal represents an absolute differential between currents utilized in said amplifier; generate a non-linearity indication based on a comparison of said difference signal with at least one reference signal; and take one of a plurality of actions based on said non-linearity indication. - View Dependent Claims (18, 19, 20, 21)
-
Specification