TOUCH POINT DETECTING DEVICE AND THE TOUCH POINT DETECTING METHOD THEREOF

• US 20120299842A1
• Filed: 08/17/2011
• Published: 11/29/2012
• Est. Priority Date: 05/28/2011
• Status: Active Grant

• Current Assignee: TPK Touch Solutions (Xiamen) Inc. (TPK Holding Co., Ltd.)
• Original Assignee: TPK Touch Solutions (Xiamen) Inc. (TPK Holding Co., Ltd.)
• Inventors: LIU, YONG
• Granted Patent: US 9,256,313 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
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• 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
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A touch point detecting device is provided. The touch point detecting device comprises a plurality of electrodes and a scanning unit connected to said electrodes and scanning said electrodes with at least two variable excitation signal frequencies. A touch point detecting method is also provided. By means of the touch point detecting device, the electrode border as well as the integrated circuit package of the processor is reduced without reducing the detection accuracy of touch points.

Claims

1. A touch point detecting device, comprising:

a plurality of electrodes;

a scanning unit connected to said electrodes and scanning said electrodes with at least two variable excitation signal frequencies.

2. The touch point detecting device of claim 1, wherein said electrodes is disposed in a first direction.

3. The touch point detecting device of claim 1, wherein said electrodes comprise a plurality of first electrodes disposed in a first direction and a plurality of second electrodes disposed in a second direction.

4. The touch point detecting device of claim 3, wherein said first direction intersects with said second direction.

5. The touch point detecting device of claim 1, wherein said electrodes are polygon.

6. The touch point detecting device of claim 1, wherein said electrodes comprise a plurality of separated conductive units and a plurality of conductive lines connecting said conductive units.

7. The touch point detecting device of claim 1, wherein said scanning unit is set within a processor.

8. The touch point detecting device of claim 1, wherein said scanning unit is set outside a processor.

9. The touch point detecting device of claim 1, wherein said electrodes are made of transparent conductive material.

10. The touch point detecting device of claim 1, wherein said electrodes are made of metal.

11. A touch point detecting method, comprising the steps of:

a) scanning electrodes with at least two variable excitation signal frequencies;

b) detecting output values generated on said electrodes where at least one touch points occur; and

c) calculating output value differences of said output values; and

d) outputting positions of said touch points on said electrodes.

12. The touch point detecting method of claim 11, further comprising a calibration step comprising:

a1) scanning said electrodes with said at least two variable excitation signal frequencies;

a2) detecting output values generated on said electrodes;

a3) calculating output value difference of said output values when said touch points occur at a first end of said electrodes;

a4) recording said output value difference as a first baseline output value difference;

a5) repeating steps

     1) and

     2) herein;

a6) calculating output value difference of said output values when said touch points occur at a second end of said electrodes; and

a7) recording said output value difference as a second baseline output value difference.

13. The touch point detecting method of claim 12, wherein said electrodes are disposed in a first direction, and said step a) further comprises:

a1) scanning said electrodes with a first excitation signal frequencies of said at least two variable excitation signal frequencies;

a2) detecting a first output value generated on said electrodes where said touch points occur;

a3) detecting said electrodes generating said first output value;

a4) scanning said electrodes generating said first output value with a second excitation signal frequencies of said at least two variable excitation signal frequencies; and

a5) detecting a second output value.

14. The touch point detecting method of claim 12, wherein said electrodes are disposed in a first direction, and said step a) further comprises:

a1) scanning said electrodes with a first excitation signal frequencies of said at least two variable excitation signal frequencies;

a2) detecting a first output value generated on said electrodes where said touch points occur;

a3) scanning said electrodes with a second excitation signal frequencies of said at least two variable excitation signal frequencies;

a4) detecting a second output value generated on said electrodes where said touch points occur; and

a5) detecting said electrodes generating said first output value and said second output value.

15. The touch point detecting method of claim 13 or 14, wherein said step b) further comprises:

b1) calculating said output value difference of said first output value and said second output value; and

b2) calculating said position of said touch point on said electrodes based on said output value difference between said first output value and said second output value, said first baseline output value difference and said second baseline output value difference.

16. The touch point detecting method of claim 13 or 14, wherein said electrodes are scanned one at a time.

17. The touch point detecting method of claim 13 or 14, wherein said electrodes are scanned synchronously.