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;

determining a noise processing method of a raw value of the capacitive touch screen according to the variation caused by the noise to the raw data of the capacitive touch screen;

performing noise cancellation processing on a first raw value set of the capacitive touch screen using the noise processing method, to obtain a first processed value set; and

determining a touch position on the capacitive touch screen according to the first processed value set;

wherein the determining the variation caused by the noise to the raw data of the capacitive touch screen comprises:

determining a phase variation caused by the noise to the raw data of the capacitive touch screen according to phase differences between a plurality of raw data sets acquired correspondingly when a drive signal is output to the capacitive touch screen in a plurality of periods, wherein the phase variation serves as the variation caused by the noise to the raw data of the capacitive touch screen.

2. The method according to claim 1 , wherein the determining the phase variation caused by the noise to the raw data of the capacitive touch screen according to the phase differences between the plurality of raw data sets acquired correspondingly when the drive signal is output to the capacitive touch screen in the plurality of periods 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 a raw value set acquired when a drive signal 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 is output to the capacitive touch screen.

3. The method according to claim 2 , wherein the phase variation ϕ caused by the noise to the raw data of the capacitive touch screen 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.

4. The method according to claim 1 , wherein the determining the variation caused by the noise to the raw data of the capacitive touch screen further comprises:

determining a raw value acquired when no drive signal is output to the capacitive touch screen as an amplitude variation caused by the noise to the raw data of the capacitive touch screen, wherein the amplitude variation serves as the variation caused by the noise to the raw data of the capacitive touch screen.

5. The method according to claim 1 , wherein the determining the noise processing method of the raw value of the capacitive touch screen according to the variation caused by the noise to the raw data of the capacitive touch screen comprises:

determining a level of the noise according to the variation caused by the noise to the raw data of the capacitive touch screen and a corresponding relationship between a variation caused by a noise to raw data of a capacitive touch screen and a noise level; and

determining the noise processing method of the raw value of the capacitive touch screen from a plurality of noise processing methods according to the level of the noise and a corresponding relationship between a noise level and a noise processing method.

6. The method according to claim 1 , wherein before the determining the noise processing method of the raw value of the capacitive touch screen according to the variation caused by the noise to the raw data of the capacitive touch screen, the method further comprises:

determining to perform noise cancellation processing on the raw value of the capacitive touch screen when the variation caused by the noise to the raw data of the capacitive touch screen is greater than or equal to a threshold value.

7. 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 determine a noise processing method of a raw value of the capacitive touch screen according to the variation caused by the noise to the raw data of the capacitive touch screen;

the processing module further configured to perform noise cancellation processing on a first raw value set of the capacitive touch screen using the noise processing method, to obtain a first processed value set; and

the processing module further configured to determine a touch position on the capacitive touch screen according to the first processed value set;

wherein the processing module is configured to determine a phase variation caused by the noise to the raw data of the capacitive touch screen according to phase differences between a plurality of raw data sets acquired correspondingly when a drive signal is output to the capacitive touch screen in a plurality of periods, wherein the phase variation serves as the variation caused by the noise to the raw data of the capacitive touch screen.

8. The touch control chip according to claim 7 , 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 a raw value set acquired when a drive signal 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 is output to the capacitive touch screen.

9. The touch control chip according to claim 8 , wherein the phase variation ϕ caused by the noise to the raw data of the capacitive touch screen 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.

10. The touch control chip according to claim 7 , wherein the processing module is further configured to:

determine a raw value acquired when no drive signal is output to the capacitive touch screen as an amplitude variation caused by the noise to the raw data of the capacitive touch screen, wherein the amplitude variation serves as the variation caused by the noise to the raw data of the capacitive touch screen.

11. The touch control chip according to claim 7 , wherein the processing module is configured to:

determine a level of the noise according to the variation caused by the noise to the raw data of the capacitive touch screen and a corresponding relationship between a variation caused by a noise to raw data of a capacitive touch screen and a noise level; and

determine the noise processing method of the raw value of the capacitive touch screen from a plurality of noise processing methods according to the level of the noise and a corresponding relationship between a noise level and a noise processing method.

12. The touch control chip according to claim 7 , wherein before the processing module determines the noise processing method of the raw value of the capacitive touch screen according to the variation caused by the noise to the raw data of the capacitive touch screen, the processing module is further configured to determine to perform noise cancellation processing on the raw value of the capacitive touch screen when the variation caused by the noise to the raw data of the capacitive touch screen is greater than or equal to a first threshold value.