Method for determining touch position and touch control chip

Patent metadata

Field	Value
Publication number	US-10691271-B2
Application number	US-201816179923-A
Country	US
Kind code	B2
Filing date	Nov 3, 2018
Priority date	Aug 1, 2017
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

The present application provides a method for determining a touch position and a touch control chip. The method includes: determining a variation caused by a noise to raw data of a capacitive touch screen; performing noise processing on a first raw value set of the capacitive touch screen according to the variation caused by the noise to the raw data of the capacitive touch screen, to obtain a first processed data set; and determining a touch position on the capacitive touch screen according to the first processed data set. The method for determining a touch position and the touch control chip provided by the present application contribute to improving accuracy of the touch position.

First claim

What is claimed is:

1. A method for determining a touch position, comprising:
determining a variation caused by a noise to raw data of a capacitive touch screen;
performing noise processing on a first raw value set of the capacitive touch screen according to the variation, to obtain a first processed data set;
determining a touch position on the capacitive touch screen according to the first processed data set; and
wherein the performing the noise processing on the first raw value set of the capacitive touch screen according to the variation, to obtain the first processed data set comprises: determining, according to the variation, a first ratio of each second processed data in a second processed data set of the capacitive touch screen to corresponding data in the first processed data set, wherein the second processed data set is obtained prior to the determination, by recursively filtering a raw value set acquired when a drive signal with a first frequency is output to the capacitive touch screen, and the first frequency is a frequency of the drive signal output to the capacitive touch screen when the first raw value set is acquired; and performing, by means of recursive filtering, the noise processing on the first raw value set according to the second processed data set and the first ratio, to obtain the first processed data set.

2. The method according to claim 1 , wherein the first ratio is 1 when the variation is greater than a configured first threshold value.

3. The method according to claim 1 , wherein the determining, according to the variation, the first ratio of each second processed data in the second processed data set of the capacitive touch screen to the corresponding data in the first processed data set comprises:
determining, according to a maximum difference between a raw value in the first raw value set and second processed data in the second processed data set, a second ratio of each second processed data in the second processed data set to corresponding data in the first processed data set; and
obtaining the first ratio according to the variation and the second ratio.

4. The method according to claim 3 , wherein the first ratio is equal to the second ratio when the variation is less than or equal to a configured second threshold value.

5. The method according to claim 4 , wherein the variation caused by the noise to the raw data of the capacitive touch screen comprises a phase variation caused by the noise to the raw data of the capacitive touch screen.

6. The method according to claim 5 , wherein the determining the variation caused by the noise to the raw data of the capacitive touch screen comprises:
determining a maximum value in a difference set between a second raw value set of the capacitive touch screen and a reference value set, wherein the second raw value set is the raw value set acquired when the drive signal with the first frequency is output to the capacitive touch screen;
determining a first sensing terminal corresponding to the maximum value; and
determining the phase variation according to a phase difference between raw data corresponding to the first sensing terminal in a first raw data set of the capacitive touch screen and raw data corresponding to the first sensing terminal in a second raw data set, wherein the first raw data set and the second raw data set are acquired when the drive signal with the first frequency is output to the capacitive touch screen.

7. The method according to claim 6 , wherein the phase variation go′ satisfies the following formula:

φ
′

=

∑

i
=
1

M

⁢

⁢



φ

i
⁢

⁢
1

-

φ

i
⁢

⁢
2



wherein M is a number of raw data corresponding to the first sensing terminal in the first raw data set, φ i1 is a phase of i th raw data corresponding to the first sensing terminal in the first raw data set, and φ i1 is a phase of i th raw data corresponding to the first sensing terminal in the second raw data set.

8. The method according to claim 3 , wherein the first ratio and the second ratio satisfy the following formula:

R
1

=

R
2

+

IQ
now

-

IQ
low

IQ
high

-

IQ
now

*

(

1
-

R
2

)

wherein R 1 is the first ratio, R 2 is the second ratio, IQ high is an upper limit value of a phase variation, and IQ low is a lower limit value of the phase variation; and
the second processed data set, the first ratio and the first raw value set satisfy the following formula:
RawData=RawDatallow*(1 −R 1 )+RawDataLast* R 1

wherein RawData is data in the first processed data set, RawDatallow is data in the first raw value set, and RawDataLast is data in the second processed data set.

9. The method according to claim 1 , wherein the method further comprises:
determining the touch position of the capacitive touch screen according to the first raw value set and a reference value set when the variation is less than or equal to a third threshold value.

10. A touch control chip, comprising:
a processing module configured to determine a variation caused by a noise to raw data of a capacitive touch screen;
the processing module further configured to perform noise processing on a first raw value set of the capacitive touch screen according to the variation, to obtain a first processed data set;
the processing module further configured to determine a touch position on the

Assignees

• Shenzhen Goodix Tech Co Ltd

Inventors

• Li Gang
• Peng Haijun
• Pang Wing Ho

Classifications

• G01D5/241

  by relative movement of capacitor electrodes · CPC title

• G06F3/04182 Primary

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

• G06F3/0446

  using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes · CPC title

• G06F2203/04101

  2.5D-digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface and also measures the distance of the input means within a short range in the Z direction, possibly with a separate measurement setup · CPC title

• G06F3/0412

  Digitisers structurally integrated in a display · CPC title