US 11,983,354 B2
Circuitry for touch-sensitive apparatus and method
Stephen William Roberts, Fareham (GB); and Peter Timothy Sleeman, Fareham (GB)
Assigned to TouchNetix Limited, Fareham (GB)
Appl. No. 17/995,513
Filed by TouchNetix Limited, Fareham (GB)
PCT Filed Mar. 29, 2021, PCT No. PCT/GB2021/050774
§ 371(c)(1), (2) Date Oct. 5, 2022,
PCT Pub. No. WO2021/219974, PCT Pub. Date Nov. 4, 2021.
Claims priority of application No. 2006301 (GB), filed on Apr. 29, 2020.
Prior Publication US 2023/0176675 A1, Jun. 8, 2023
Int. Cl. G06F 3/041 (2006.01); G06F 3/044 (2006.01)
CPC G06F 3/0416 (2013.01) [G06F 3/0446 (2019.05)] 17 Claims
OG exemplary drawing
 
1. Circuitry for calculating the magnitude of a received signal from an electrode of a capacitive touch sensitive apparatus, the circuitry comprising:
a first digital signal generator configured to generate a first digital signal, the first digital signal representing a sinusoidal wave having a first frequency;
a second digital signal generator configured to generate a second digital signal, the second digital signal representing a sinusoidal wave having the first frequency, wherein the second digital signal is orthogonal to the first digital signal;
sensing circuitry for coupling to an electrode array, the sensing circuitry configured to receive the first digital signal, provide a driving signal to at least one electrode of the electrode array, wherein the driving signal is an analogue signal converted from the first digital signal, and output a received digital signal, wherein the received digital signal is indicative of a capacitive coupling experienced by the at least one electrode;
a first multiplier configured to receive the first digital signal and the received digital signal and multiply the two digital signals together;
a second multiplier configured to receive the second digital signal and the received digital signal and multiply the two digital signals together; and
a signal magnitude calculator configured to calculate the magnitude of the received digital signal based on the output from the first multiplier and the second multiplier.