US 11,868,561 B2
Multi-phase exciting and scanning with zero-sum sequences
Volodymyr Bihday, Lviv (UA); Andriy Maharyta, Lviv (UA); Igor Kravets, Lviv (UA); Mykhaylo Krekhovetskyy, Lviv (UA); and Ihor Musijchuk, Lviv (UA)
Assigned to Cypress Semiconductor Corporation, San Jose, CA (US)
Filed by Cypress Semiconductor Corporation, San Jose, CA (US)
Filed on May 26, 2021, as Appl. No. 17/331,389.
Prior Publication US 2022/0382451 A1, Dec. 1, 2022
Int. Cl. G06F 3/041 (2006.01); G06F 3/044 (2006.01)
CPC G06F 3/041662 (2019.05) [G06F 3/044 (2013.01); G06F 3/0418 (2013.01); G06F 3/04164 (2019.05)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
generating an in-phase drive signal and an opposite-phase drive signal;
selecting a sequence having a number of one values, negative one values, and zero values, wherein the one values correspond to the in-phase drive signal, the negative one values correspond to the opposite-phase drive signal, and the zero values correspond to a reference signal, wherein the reference signal is from a voltage potential or a ground potential, and wherein a sum of the sequence is equal to zero;
applying, at a substantially same time to each of a first set of transmitter electrodes at a first stage of a plurality of scanning stages, (i) at least one of the in-phase drive signal or the opposite-phase drive signal and (ii) the reference signal according to the sequence;
rotating the sequence to obtain a rotated sequence;
applying, at a substantially same time to each of a second set of transmitter electrodes at a second stage of the plurality of scanning stages, (i) at least one of the in-phase drive signal or the opposite-phase drive signal and (ii) the reference signal according to the rotated sequence; and
receiving sense signals from a set of receiver electrodes to detect a presence of an object on a touch panel, wherein the sense signals represent capacitances associated with the set of receiver electrodes.