Method for determining touch position and touch control chip

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 capacitive touch screen according to the first processed data set; and

wherein the processing module is configured to: determine, 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 perform, 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.

11. The touch control chip according to claim 10 , wherein the first ratio is 1 when the variation is greater than a configured first threshold value.

12. The touch control chip according to claim 10 , wherein the processing module is configured to:

determine, 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

obtain the first ratio according to the variation and the second ratio.

13. The touch control chip according to claim 12 , wherein the first ratio is equal to the second ratio when the variation is less than or equal to a configured second threshold value.

14. The touch control chip according to claim 13 , 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.

15. The touch control chip according to claim 14 , wherein the processing module is configured to:

determine 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;

determine a first sensing terminal corresponding to the maximum value; and

determine 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.

16. The touch control chip according to claim 15 , 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 i2 is a phase of i th raw data corresponding to the first sensing terminal in the second raw data set.

17. The touch control chip according to claim 12 , 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.

18. The touch control chip according to claim 10 , wherein the processing module is further configured to determine 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.