Method for Determining Touch Point Displacement and Associated Apparatus

• US 20110025628A1
• Filed: 07/27/2010
• Published: 02/03/2011
• Est. Priority Date: 07/31/2009
• Status: Active Grant

• Current Assignee: Xueshan Technologies Inc. (Wi-LAN Inc.)
• Original Assignee: MStar Semiconductor Incorporated (MediaTek, Inc.)
• Inventors: Wen, Chao-Cheng, Lin, Tsung-Fu
• Granted Patent: US 8,994,697 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text

Abstract

A method for determining a displacement of a touch point is applied to a touch panel to reduce noise interfering with determination of the displacement. The method includes obtaining a displacement according to a movement of a touch point on the touch panel; checking whether the displacement is within a predetermined range; and determining that the movement is valid when the displacement is within the predetermined range.

Claims

1. A method for determining a displacement of a touch point, applied to a touch panel, comprising:

obtaining the displacement according to a movement of the touch point on the touch panel;

checking whether the displacement is within a predetermined range; and

determining that the movement is valid when the displacement is within the predetermined range.

2. The method as claimed in claim 1, further comprising:

discarding the displacement when the displacement is not within the predetermined range.

3. The method as claimed in claim 1, wherein the step of obtaining the displacement according to the movement of the touch point on the touch panel comprises:

performing a first calculation on the movement of the touch point to obtain the displacement.

4. The method as claimed in claim 3, wherein the first calculation is a normalizing calculation.

5. The method as claimed in claim 1, wherein the movement of the touch point is detected within a time interval.

6. The method as claimed in claim 5, wherein the step of obtaining the displacement according to the movement of the touch point on the touch panel comprises:

generating a plurality of reference displacements according to a start position of the touch point at a start point of the time interval and a plurality of end positions of the touch point at an end point of the time interval; and

performing a second calculation on the plurality of reference displacements to obtain the displacement.

7. The method as claimed in claim 6, wherein the second calculation is an average calculation.

8. The method as claimed in claim 1, wherein the predetermined range is determined by a first predetermined value and a second predetermined value, and the step of checking whether the displacement is within the predetermined range comprises:

comparing the displacement with the first predetermined value and the second predetermined value to check whether the displacement is within a predetermined range.

9. The method as claimed in claim 8, wherein the displacement is determined as being within the predetermined range when the displacement is greater than the first predetermined value and is smaller than the second predetermined value.

10. The method as claimed in claim 1, wherein the displacement is a component of the movement of the touch point in one direction.

11. An apparatus for determining a displacement of a touch point, comprising:

a detecting module, for detecting the displacement according to a movement of the touch point on a touch panel;

a checking module, for checking whether the displacement is within a predetermined range; and

a determining module, for determining that the movement is valid when the check result indicates that the displacement is within the predetermined range.

12. The apparatus as claimed in claim 11, wherein the determining module discards the displacement when the check result indicates that the displacement is not within the predetermined range.

13. The apparatus as claimed in claim 11, wherein the detecting module comprises a calculating module for performing a first calculation to generate the displacement.

14. The apparatus as claimed in claim 13, wherein the first calculation is a normalizing calculation.

15. The apparatus as claimed in claim 11, further comprising:

a time module, for generating a time signal;

wherein, the detecting module determines a time interval according to the time signal, and detects the movement of the touch point within the time interval to generate the displacement.

16. The apparatus as claimed in claim 15, wherein the detecting module comprises a calculating module, for generating a plurality of reference displacements according to a start position of the touch point at a start point of the time interval and a plurality of end positions of the touch point at an end point of the time interval, and performs a second calculation on the plurality of reference displacements to generate the displacement.

17. The apparatus as claimed in claim 16, wherein the second calculation is an average calculation.

18. The apparatus as claimed in claim 11, wherein the predetermined range is determined by a first predetermined value and a second predetermined value, and the checking module compares the displacement with the first predetermined value and the second predetermined value to check whether the displacement is within a predetermined range.

20. The apparatus as claimed in claim 11, wherein the displacement is a component of the movement of the touch point in one direction.

19. The apparatus as claimed in claim 19, wherein the checking module determines the displacement as being within the predetermined range when the displacement is greater than the first predetermined value and is smaller than the second predetermined value