Noise reduction method and system for touch detection device

1. A noise reduction method for a touch detection device, wherein touch detection nodes of the touch detection device are divided into one or more groups and the noise reduction method comprises:

step A, performing a synchronous sampling on the touch detection nodes in one same group and storing the sampling data;

step B, comparing each sampling data against a corresponding reference data to calculate a differential data which, as a detection data, replaces a corresponding original sampling data;

step C, calculating statistics of the replacing detection data obtained at step B to screen out, according to a predetermined screening condition, valid data to calculate a DC offset component indicative of a noise ingredient; and

step D, obtaining noise-filtered detection data by subtracting the DC offset component obtained at step C from each detection data obtained at step B;

wherein step C further comprises:

step C 31 , setting a dividing value for screening out valid data;

step C 32 , calculating an average of a group of detection data obtained at step B;

step C 33 , using the average as a center and the dividing value as an amplitude to determine a scope and screen out the detection data in the scope as valid data according to the dividing value set at step C 31 and the average obtained at step C 32 ; and

step C 34 , calculating an average of the valid data screened out at step C 33 , the obtained average being considered as the desired DC offset component.

2. A noise reduction system for a touch detection device, touch detection nodes of the touch detection device being divided into one or more groups, the noise reduction system comprising:

a sampling unit configured to perform a synchronous sampling on the touch detection nodes belonging to the same group and store the sampling data;

a differential value calculating unit configured to compare each sampling data against a corresponding reference data to calculate a differential data to replace a corresponding original sampling data;

a noise calculating unit configured to calculate statistics of the replacing detection data obtained by the differential value calculating unit to screen out, according to a predetermined screening condition, valid data to calculate a DC offset component indicative of a noise ingredient; and

a noise filtering unit configured to obtain noise-filtered detection data by subtracting the DC offset component obtained by the noise calculating unit from each detection data calculated by the differential value calculating unit;

wherein the noise calculating unit comprises:

a valid data dividing value setting module configured to set a dividing value for screening valid data;

an average calculating module configured to calculate an average of the group of detection data;

a valid data screening module configured to use the average as a center and the dividing value as an amplitude to determine a scope and screen out the detection data in the scope as valid data according to the dividing value set by the valid data dividing value setting module and the average obtained by the average calculating module; and

a DC offset component determining module configured to calculate an average of the valid data screened out by the valid data screening module, the average obtained being considered as the desired DC offset component.

3. A touch terminal comprising a touch detection device, the touch detection device comprising:

a touch sensor unit; and

a touch controller unit coupled to the touch sensor unit, wherein the touch controller unit comprises a noise reduction system, touch detection nodes of the touch detection device being divided into one or more groups, the noise reduction system comprising:

a sampling unit configured to perform a synchronous sampling on the touch detection nodes belonging to the same group and store the sampling data;

a differential value calculating unit configured to compare each sampling data against a corresponding reference data to calculate a differential data to replace a corresponding original sampling data;

a noise calculating unit configured to calculate statistics of the replacing detection data obtained by the differential value calculating unit to screen out, according to a predetermined screening condition, valid data to calculate a DC offset component indicative of a noise ingredient; and

a noise filtering unit configured to obtain noise-filtered detection data by subtracting the DC offset component obtained by the noise calculating unit from each detection data calculated by the differential value calculating unit;

wherein the noise calculating unit comprises:

a valid data dividing value setting module configured to set a dividing value for screening valid data;

an average calculating module configured to calculate an average of the group of detection data;

a valid data screening module configured to use the average as a center and the dividing value as an amplitude to determine a scope and screen out the detection data in the scope as valid data according to the dividing value set by the valid data dividing value setting module and the average obtained by the average calculating module; and

a DC offset component determining module configured to calculate an average of the valid data screened out by the valid data screening module, the average obtained being considered as the desired DC offset component.