Touch sensor and method for deriving a stylus position
A stylus includes a first sensor configured to receive a first receive signal from a touch sensor of a device, and a second sensor configured to receive a second receive signal from the touch sensor of the device. The stylus includes an amplifier coupled to the first and second sensors and configured to produce a third signal by amplifying the difference between the first receive signal and the second receive signal. The stylus includes a controller configured to decode information encoded in the first receive signal and the second receive signal by processing the third signal.
1 . A stylus comprising:
a receiver configured to receive signal including a first signal and a second signal, the first signal transmitted from a first portion of a touch sensor, the second signal transmitted from a second portion of the touch sensor at the same time as the first signal is transmitted, the second signal including a third signal derived from inverting the first signal; and
transmitter configured to transmit, after the receiver has received the signal including the first signal and the second signal, a stylus signal to the touch sensor, the stylus signal used to detect a position of the stylus.
2 . The stylus of claim 1 , wherein the first portion includes a transmission electrode located at a first position of the touch sensor and the second portion includes a transmission electrode located at a second position different from the first position of the touch sensor.
3 . A method comprising:
transmitting a first signal from a first portion of a touch sensor, and at the same time transmitting a second signal from a second portion of the touch sensor, wherein the second signal includes a third signal derived from inverting the first signal; and
deriving a position of a stylus based on a stylus signal transmitted from the stylus that has received a signal including the first signal and the second signal.
4 . The method of claim 3 , wherein the first portion includes a transmission electrode located at a first position of the touch sensor and the second portion includes a transmission electrode located at a second position different from the first position of the touch sensor.
5 . A touch sensor comprising:
a first portion configured to transmit a first signal;
a second portion configured to transmit a second signal, which includes a third signal derived from inverting the first signal, at the same time as transmission of the first signal; and
a processor configured to derive a position of a stylus based on a stylus signal transmitted from the stylus that has received a signal including the first signal and the second signal.
6 . The touch sensor of claim 5 , wherein the first portion includes a transmission electrode located at a first position of the touch sensor and the second portion includes a transmission electrode located at a second position different from the first position of the touch sensor.