Method For Determining The Number Of Fingers On A Sensing Device

• US 20090184934A1
• Filed: 07/01/2008
• Published: 07/23/2009
• Est. Priority Date: 01/17/2008
• Status: Active Grant

• Current Assignee: Touchscreen Gestures LLC
• Original Assignee: Touchscreen Gestures LLC
• Inventors: Liu, Yen-Fu, Shen, John, Lin, Jao-Ching, Chu, Linabel
• Granted Patent: US 8,760,411 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• 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
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

A method for determining the number of fingers on a sensing device, which has a plurality of scanlines, includes the steps of: identifying the scanlines that generate a detecting signal, which has a value greater than a threshold value; finding adjacent ones of the scanlines; forming at least one group from the adjacent ones of the scanlines thus found; and counting the number of the scanlines in the at least one group thus formed in order to determine the number of fingers on the sensing device.

Claims

1. A method for determining the number of fingers on a sensing device that has a plurality of scanlines, said method comprising the steps of:

A) scanning the scanlines;

B) identifying the scanlines scanned in step A) that generate a detecting signal, which has a value greater than a threshold value;

C) finding adjacent ones of the scanlines identified in step B);

D) forming at least one group from the adjacent ones of the scanlines found in step C); and

E) counting the number of the scanlines in the at least one group formed in step D) in order to determine the number of fingers on the sensing device.

2. The method as claimed in claim 1, wherein, in step E), the number of the fingers in a group formed in step D) is determined to be one when the number of the scanlines in the group is not greater than a predetermined value.

3. The method as claimed in claim 2, further comprising the step of obtaining a position of the finger on the sensing device based on the values of the detecting signals of the scanlines in the corresponding group.

4. The method as claimed in claim 1, wherein, in step E), the number of the fingers in a group formed in step D) is determined to be more than one when the number of the scanlines in the group is greater than a predetermined value.

5. The method as claimed in claim 4, further comprising the step of obtaining positions of the fingers on the sensing device based on the values of the detecting signals of the scanlines in the corresponding group.

6. The method as claimed in claim 1, wherein, in step A), the scanlines are scanned using one of an interlaced scanning and a non-interlaced scanning.

7. A method for determining the number of fingers on a sensing device that has a plurality of first scanlines, and a plurality of second scanlines that intersect the first scanlines, said method comprising the steps of:

A) scanning the first and second scanlines;

B) identifying the first and second scanlines scanned in step A) that generate a detecting signal, which has a value greater than a threshold value;

C) finding adjacent ones of the first scanlines and adjacent ones of the second scanlines identified in step B);

D) forming at least one first group from the adjacent ones of the first scanlines found in step C), and at least one second group from the adjacent ones of the second scanlines found in step C);

E) when the number of the at least one first group is equal to the number of the at least one second group formed in step D), counting the number of the first scanlines in the at least one first group formed in step D) in order to determine the number of the fingers on the sensing device;

F) when the number of the at least one first group is less than the number of the at least one second group formed in step D), counting the number of the first scanlines in the at least one first group formed in step D) in order to determine the number of the fingers on the sensing device; and

G) when the number of the at least one second group is less than the number of the at least one first group formed in step D), counting the number of the second scanlines in the at least one second group formed in step D) in order to determine the number of the fingers on the sensing device.

8. The method as claimed in claim 7, wherein, in step E), the number of the fingers in a first group formed in step D) is determined to be one when the number of the first scanlines in the first group is not greater than a predetermined value.

9. The method as claimed in claim 8, further comprising the step of obtaining a position of the finger on the sensing device based on the values of the detecting signals of the first scanlines in the corresponding first group.

10. The method as claimed in claim 7, wherein, in step E), the number of the fingers in a first group formed in step D) is determined to be more than one when the number of the first scanlines in the first group is greater than a predetermined value.

11. The method as claimed in claim 10, further comprising the step of obtaining positions of the fingers on the sensing device based on the values of the detecting signals of the first scanlines in the corresponding first group.

12. The method as claimed in claim 7, wherein, in step F), the number of the fingers in a first group formed in step D) is determined to be one when the number of the first scanlines in the first group is not greater than a predetermined value.

13. The method as claimed in claim 12, further comprising the step of obtaining a position of the finger on the sensing device based on the values of the detecting signals of the first scanlines in the corresponding first group.

14. The method as claimed in claim 7, wherein, in step F), the number of fingers in a first group formed in step D) is determined to be more than one when the number of the first scanlines in the first group is greater than a predetermined value.

15. The method as claimed in claim 14, further comprising the step of obtaining positions of the fingers on the sensing device based on the values of the detecting signals of the first scanlines in the corresponding first group.

16. The method as claimed in claim 7, wherein, in step G), the number of the fingers in a second group formed in step D) is determined to be one when the number of the second scanlines in the second group is not greater than a predetermined value.

17. The method as claimed in claim 16, further comprising the step of obtaining a position of the finger on the sensing device based on the values of the detecting signals of the second scanlines in the corresponding second group.

18. The method as claimed in claim 7, wherein, in step G), the number of fingers in a second group formed in step D) is determined to be more than one when the number of the second scanlines in the second group is greater than a predetermined value.

19. The method as claimed in claim 18, further comprising the step of obtaining positions of the fingers on the sensing device based on the values of the detecting signals of the second scanlines in the corresponding second group.

20. The method as claimed in claim 7, wherein, in step A), at least one of the first scanlines and the second scanlines are scanned using one of an interlaced scanning and a non-interlaced scanning.