METHOD FOR DETERMINING TOUCH POINTS ON TOUCH PANEL AND SYSTEM THEREOF

• US 20110279386A1
• Filed: 06/23/2010
• Published: 11/17/2011
• Est. Priority Date: 05/14/2010
• Status: Active Grant

• Current Assignee: Alcorlink Corp.
• Original Assignee: Alcor Micro Corp.
• Inventors: Wang, Chuen-Heng, Chang, Chi-Tung
• Granted Patent: US 8,350,819 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184

Abstract

The present invention discloses a method for determining touch points on a touch panel and a system thereof. The method includes the following steps: sampling, calculating a difference, comparing the difference, sampling a determinative area, and calculating a barycenter. The barycenter position from the said steps is a touch point position. The present invention can overcome the problem of the ghost point in traditional touch panels and also be applicable for touch panels of various types.

Claims

1. A method for determining touch points on a touch panel, comprising:

a sampling step for acquiring a first sensed value of each of sensors on the touch panel and storing the first sensed values;

a difference calculating step for acquiring a second sensed value of each of the sensors and then acquiring a difference of each of the sensors, wherein the difference is obtained by subtracting the second sensed value sensed by each of the sensors from the first sensed value;

a difference comparing step for comparing each of the differences with a preset threshold value and defining a touched sensor, wherein the difference of the touched sensor is greater than the preset threshold value and greater than the difference of each of the sensors adjacent to the touched sensor;

a determinative area sampling step for acquiring each of the differences of the sensors in a determinative area, wherein the determinative area is centered around the touched sensor; and

a barycenter calculating step for calculating a barycenter position according to each of the differences acquired in the determinative area sampling step, wherein the barycenter position comprises a longitudinal coordinate and a horizontal coordinate,

wherein the barycenter position is a position of the touch point.

2. The method of claim 1, wherein the determinative area is formed by the sensors surrounding the touched sensor.

3. The method of claim 2, wherein the longitudinal coordinate is equal to a divisional result obtained by dividing a sum of each of the differences in the determinative area multiplied by a relative position longitudinal coordinate thereof with a sum of the differences, and the horizontal coordinate is equal to a divisional result obtained by dividing the sum of each of the differences in the determinative area multiplied by a relative position horizontal coordinate thereof with the sum of the differences.

4. The method of claim 3, wherein the preset threshold value is obtained by calculating an average value and a standard deviation according to each of the differences of the sensors in an area and adding up the average value and the standard deviation according to a ratio.

5. The method of claim 4, wherein the area comprises all of the sensors on the touch panel.

6. The method of claim 1, wherein the longitudinal coordinate is equal to a divisional result obtained by dividing a sum of each of the differences in the determinative area multiplied by a relative position longitudinal coordinate thereof with a sum of the differences, and the horizontal coordinate is equal to a divisional result obtained by dividing the sum of each of the differences in the determinative area multiplied by a relative position horizontal coordinate thereof with the sum of the differences.

7. The method of claim 6, wherein the preset threshold value is obtained by calculating an average value and a standard deviation according to each of the differences of the sensors in an area and adding up the average value and the standard deviation according to a ratio.

8. The method of claim 7, wherein the area comprises all of the sensors on the touch panel.

9. A system for determining touch points on a touch panel by using sensors on the touch panel, the system comprising:

a sampling module electrically connected to the touch panel, being configured to acquire a first sensed value of each of the sensors on the touch panel and store the first sensed values;

a difference calculating module electrically connected to the sampling module, being configured to acquire a second sensed value of each of the sensors and then acquire a difference of each of the sensors, wherein the difference is obtained by subtracting the second sensed value sensed by each of the sensors from the first sensed value;

a difference comparing module electrically connected to the difference calculating module, being configured to compare each of the differences with a preset threshold value and define a touched sensor, wherein the difference of the touched sensor is greater than the preset threshold value and greater than the difference of each of the sensors adjacent to the touched sensor;

a determinative area sampling module electrically connected to the difference comparing module, being configured to acquire each of the differences of the sensors in a determinative area, wherein the determinative area is centered around the touched sensor; and

a barycenter calculating module, being configured to calculate a barycenter position according to each of the differences acquired by the determinative area sampling module, wherein the barycenter position comprises a longitudinal coordinate and a horizontal coordinate,

wherein the barycenter position is a position of the touch point.

10. The system of claim 9, wherein the determinative area is formed by the sensors surrounding the touched sensor.

11. The system of claim 10, wherein the longitudinal coordinate is equal to a divisional result obtained by dividing a sum of each of the differences in the determinative area multiplied by a relative position longitudinal coordinate thereof with a sum of the differences, and the horizontal coordinate is equal to a divisional result obtained by dividing the sum of each of the differences in the determinative area multiplied by a relative position horizontal coordinate thereof with the sum of the differences.

12. The system of claim 11, wherein the preset threshold value is obtained by calculating an average value and a standard deviation according to each of the differences of the sensors in an area and adding up the average value and the standard deviation according to a ratio.

13. The system of claim 12, wherein the area comprises all of the sensors on the touch panel.

14. The system of claim 9, wherein the longitudinal coordinate is equal to a divisional result obtained by dividing a sum of each of the differences in the determinative area multiplied by a relative position longitudinal coordinate thereof with a sum of the differences, and the horizontal coordinate is equal to a divisional result obtained by dividing the sum of each of the differences in the determinative area multiplied by a relative position horizontal coordinate thereof with the sum of the differences.

15. The system of claim 14, wherein the preset threshold value is obtained by calculating an average value and a standard deviation according to each of the differences of the sensors in an area and adding up the average value and the standard deviation according to a ratio.

16. The system of claim 15, wherein the area comprises all of the sensors on the touch panel.