Electronic device with touch sensor and driving method thereof

Patent metadata

Field	Value
Publication number	US-9417730-B2
Application number	US-201414473116-A
Country	US
Kind code	B2
Filing date	Aug 29, 2014
Priority date	Sep 3, 2013
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

An electronic device with a touch sensor comprises: a touch screen including touch sensors defined by Tx lines and Rx lines; a touch sensing circuit that supplies a drive signal to the Tx lines and senses a voltage change in the touch sensors to output sensing data; and a noise filtering unit that profiles the type of noise in the sensing data and compensates the sensing data so that the sensing data is near the maximum threshold or the minimum threshold, which is calculated based on a average value of the previous frame, or within the range between the maximum and minimum thresholds.

First claim

What is claimed is:

1. An electronic device with a touch sensor, the electronic device comprising:
a touch screen including touch sensors defined by Tx lines and Rx lines;
a touch sensing circuit that supplies a drive signal to the Tx lines and senses a voltage change in the touch sensors to output sensing data; and
a microcontroller executing program instructions stored in a memory, which is configured to perform noise filtering, which;
profile a type of noise in the sensing data in order to compensate the sensing data so that the compensated sensing data is near a maximum threshold or a minimum threshold which is calculated based on an average value of the sensing data of a previous frame, or within a range between the maximum and the minimum thresholds;
compare the average value of the sensing data with a preset touch threshold, determine whether the sensing data is classified as touch or no touch, and set sensing data classified as touch being a first parameter and set sensing data classified as no touch being a second parameter.

2. The electronic device of claim 1 , wherein the microcontroller is configured to:
calculate a reference value by using N samples of sensing data (N is an integer equal to or greater than 2); and
subtract an average value of the first parameter and an average value of the second parameter, respectively, from the reference value, compare resultant values from the respective subtractions to determine which of the first and the second parameters to apply, and define data regions classified as noise by using the determined parameter.

3. The electronic device of claim 2 , wherein the microcontroller is configured to calculate the maximum and minimum thresholds for first and second modes in order to define data regions classified as noise by using the determined parameter, and update the maximum and minimum thresholds every frame.

4. The electronic device of claim 3 , wherein the maximum threshold for the first mode is calculated by a first equation: average value of previous frame+average value of previous frame*gain,
the minimum threshold for the first mode is calculated by a second equation: average value of previous frame−average value of previous frame*gain,
the maximum threshold for the second mode is calculated by the second equation: average value of previous frame−average value of previous frame*gain, and
the minimum threshold for the second mode is calculated by the second equation: average value of previous frame−average value of previous frame*gain.

5. The electronic device of claim 1 , wherein the microcontroller is configured to compare the sensing data with the maximum threshold and the minimum threshold, and if the sensing data has a value other than the maximum threshold and the minimum threshold, compensate the sensing data.

6. The electronic device of claim 5 , wherein the microcontroller is configured to compare the sensing data with the maximum threshold and the minimum threshold and compensate the sensing data so that the sensing data is near the maximum threshold, near the minimum threshold or within the range between the maximum and minimum thresholds M times (M is an integer equal to or greater than 1) or more.

7. A driving method of an electronic device with a touch sensor, the method comprising:
acquiring sensing data, comparing an average value of the sensing data with a preset touch threshold, determining whether the sensing data is classified as touch or no touch, and setting sensing data classified as touch being a first parameter and sensing data classified as no touch being a second parameter;
calculating a reference value, subtracting an average value of the first parameter and an average value of the second parameter, respectively, comparing resultant values from the respective subtractions, and determining which of the first and the second parameters to apply;
calculating a maximum and minimum thresholds for first and second modes based on an average value of the sensing data of the previous frame in order to define data regions classified as noise by using the determined parameter; and
comparing the sensing data with the maximum threshold and the minimum threshold, and if the sensing data has a value other than the maximum threshold and the minimum threshold, compensating the sensing data so that the sensing data is near the maximum threshold or the minimum threshold, which is calculated based on the average value of the sensing data of the previous frame, or within the range between the maximum and minimum thresholds.

8. The method of claim 7 , wherein the maximum threshold for the first mode is calculated by a first equation: average value of previous frame+average value of previous frame*gain, the minimum threshold for the first mode is calculated by a second equation: average value of previous frame−average value of previous frame*gain, the maximum threshold for the second mode is calculated by the second equation: average value of previous frame−average value of previous frame*gain, and the minimum threshold for the second mode is calculated by the second equation: average value of previous frame−average value of previous frame*gain.

9. The method of claim 8 , wherein the procedure of comparing the sensing data with the maximum threshold and the minimum threshold and compensating the sensing data so that the sensing data is near the maximum threshold, near the minimum threshold or within the range between the maximum and minimum thresholds is performed M times (M is an integer equal to or greater than 1) or more.

Assignees

• Lg Display Co Ltd

Inventors

• Shin Sunkyung

Classifications

• G06F3/0418 Primary

  for error correction or compensation, e.g. based on parallax, calibration or alignment · CPC title

• G06F3/0416

  Control or interface arrangements specially adapted for digitisers · CPC title

• G06F3/044

  by capacitive means · CPC title