Noise reduction method and system for touch detection device

• US 9,946,378 B2
• Filed: 09/27/2013
• Issued: 04/17/2018
• Est. Priority Date: 03/28/2011
• Status: Active Grant

• Current Assignee: Shenzhen Goodix Technology Co., Ltd.
• Original Assignee: Shenzhen Goodix Technology Co., Ltd.
• Inventors: Deng, Gengchun, Chen, Xiaoxiang
• Primary Examiner(s): FLORES, ROBERTO W
• Application Number:
  US14/038,791
• Publication Number:
  US 20140028620A1
• Time in Patent Office: 1,663 Days
• Field of Search: 345173-178, 178 1801- 1807
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer

Abstract

Noise reduction method and system for a touch detection device are disclosed. The noise reduction method includes: 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 to screen out 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 from each detection data.

Claims

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 C41, setting a plurality of mutually exclusive data ranges each having a preset upper limit and a preset lower limit;

step C42, comparing each detection data of a group of detection data obtained at step B with the preset upper limit and the preset lower limit of each of the plurality of mutually exclusive data ranges to determine which data range each detection data of the group of detection data falls in;

step C43, calculating the number of detection data in each data range to identify a most concentrated data range in which the number of the detection data fall is greatest; and

step C44, calculating an average of all the detection data in the most concentrated data range, the obtained average being considered as a DC offset component; and

step D, obtaining noise-filtered detection data by subtracting the DC offset component obtained at step C44 from each detection data obtained at step B.