Phase compensation method for multi-scan in touch sensing system and phase compensation circuit thereof

Patent metadata

Field	Value
Publication number	US-10152148-B2
Application number	US-201414475582-A
Country	US
Kind code	B2
Filing date	Sep 3, 2014
Priority date	Apr 23, 2014
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

A phase compensation method for multi-scan in touch sensing system is provided. The phase compensation method includes the following steps. A plurality of carrier signals are received, and a demodulating operation is preformed on each of the carrier signals to obtain a first component signal and a second component signal of each of the carrier signals. An inverse matrix operation is respectively preformed on the first component signal and the second component signal both demodulated by the demodulating operation. A signal mixing operation is preformed on the first component signal and the second component signal both processed by the inverse matrix operation to obtain raw data of each of the carrier signals. Furthermore, a phase compensation circuit applying afore-said phase compensation method is also provided.

First claim

What is claimed is:

1. A phase compensation method for multi-scan in touch sensing system, the method comprising:
receiving a plurality of carrier signals, and performing a demodulating operation on each of the carrier signals to obtain a first component signal and a second component signal of each of the carrier signals, wherein the received carrier signals are generated from a plurality of carrier signals having been transmitted to a touch panel and processed by a touch panel matrix;
respectively performing an inverse matrix operation by an inverse matrix determined at least according to the touch panel matrix on each of the first component signals and the second component signals each demodulated by the demodulating operation; and
performing a signal mixing operation on the first component signals and the second component signals each processed by the inverse matrix operation to obtain data carried on each of the carrier signals.

2. The phase compensation method of claim 1 , wherein the step of respectively performing the inverse matrix operation on each of the first component signals and the second component signals each demodulated by the demodulating operation comprises:
via a signal processing channel, performing the inverse matrix operation on the first component signals demodulated by a first demodulating operation and the second component signals demodulated by a second demodulating operation.

3. The phase compensation method of claim 1 , wherein the step of respectively performing the inverse matrix operation on each of the first component signals and the second component signals each demodulated by the demodulating operation comprises:
via a first signal processing channel, performing the inverse matrix operation on the first component signals demodulated by a first demodulating operation; and
via a second signal processing channel, performing the inverse matrix operation on the second component signals demodulated by a second demodulating operation.

4. The phase compensation method of claim 3 , wherein the first component signals are one of an in-phase signal and a quadrature signal in a quadrature amplitude modulation mode, and the second component signals are another one of the in-phase signal and the quadrature signal in the quadrature amplitude modulation mode.

5. The phase compensation method of claim 4 , wherein the first demodulating operation is one selected from an in-phase demodulating operation and a quadrature demodulating operation in correspondence to the first component signals, and the second demodulating operation is another one selected from the in-phase demodulating operation and the quadrature demodulating operation in correspondence to the second component signals.

6. The phase compensation method of claim 1 , wherein the received carrier signals are already processed by a matrix operation before being received, and the inverse matrix operation processes the first component signals and the second component signals each demodulated by the demodulating operation in correspondence to the matrix operation.

7. The phase compensation method of claim 1 , wherein the step of performing the signal mixing operation on the first component signals and the second component signals each processed by the inverse matrix operation comprises:
respectively performing a power operation on each of the first component signals with the inverse matrix operation processed and on each of the second component signals with the inverse matrix operation processed to perform the phase compensation on each of the first component signals and the second component signals; and
performing a summation operation on the first component signals and the second component signals each processed by the power operation.

8. The phase compensation method of claim 7 , wherein the step of performing the signal mixing operation on the first component signals and the second component signals each processed by the inverse matrix operation further comprises:
performing a radical operation on the first component signals and the second component signals each processed by the power operation.

9. The phase compensation method of claim 1 , wherein the step of respectively performing the inverse matrix operation on each of the first component signals and the second component signals each demodulated by the demodulating operation is performed before the step of performing the signal mixing operation on the first component signals and the second component signals each processed by the inverse matrix operation to obtain the data carried on each of the carrier signals.

10. The phase compensation method of claim 1 , wherein the step of performing the demodulating operation on each of the carrier signals to obtain the first component signal and the second component signal of each of the carrier signals comprises:
respectively receiving a first demodulating signal and a second demodulating signal, and mixing each of the carrier signals with the first demodulating signal and the second demodulating signal; and
performing a filtering operation on each of the carrier signals including the first demodulating signal and on each of the carrier signals including the second demodulating signal to obtain the first component signal and the second component signal of each of the carrier signals.

11. The phase compensation method of claim 1 , wherein the power operation is a square operation.

12. A phase compensation circuit for multi-scan in touch sensing system, comprising:
a plurality of demodulators, receiving a plurality of carrier signals, and performing a demodulating operation on each of the carrier signals to obtain a first component signal and a second component signal of each of the carrier signals, wherein the received carrier signals are generated from a plurality of carrier signals having been transmitted to a touch panel and processed by a touch panel matrix; and
a processor, configured to:
respectively perform an inverse matrix operation by an inverse matrix determined at least according to the touch panel matrix on each of the first component signals and the second component signals each demodulated by the demodulating operation; and
perform a signal mixing operation on the first component signals and the second component signals each processed by the inverse matrix operation to obtain data carried on each of the carrier signals.

13. The phase compensation circuit of claim 12 , wherein each of the demodulators comprises:
an amplifier, configured to receive and amplify the corresponding one of the carrier signals to transfer the corresponding one of the carrier signals to the first demodulating channel and the second demodulating channel of the demodulator.

14. The phase compensation circuit of claim 12 , further comprising:
a signal generator, configured to generate the first demodulating signal and the second demodulating signal.

15. The phase compensation circuit of claim 12 , wherein the processor comprises:
a signal processing channel, configured to perform the inverse matrix operation on each of the first component signals and the second component signals.

16. The phase compensation circuit of claim 12 , wherein the processor comprises:
a first signal processing channel, configured to perform the inverse matrix operation on the first component signals; and
a second signal processing channel, configured to perform the inverse matrix operation on the second component signals.

17. The phase compensation circuit of claim 16 , wherein the first component signals are one of an in-ph

Assignees

• Novatek Microelectronics Corp

Inventors

• Kuo Hung-Cheng
• Chang Tsen-Wei
• Chen Chun-Hung

Classifications

• G06F2218/02

  Preprocessing · CPC title

• G06F3/041 Primary

  Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means · CPC title

• G06K9/00503

  Physics · mapped topic

• G06F3/0416

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/04182 Primary

  Filtering of noise external to the device and not generated by digitiser components · CPC title