MULTI-TOUCH DETECTION METHOD FOR TOUCH PANEL

• US 20110018837A1
• Filed: 06/29/2010
• Published: 01/27/2011
• Est. Priority Date: 07/24/2009
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: InnoLux Corporation
• Inventors: CHENG, CHIEN-YUNG, PAN, HSUAN-LIN, SHIH, PO-SHENG, CHEN, PO-YANG
• Granted Patent: US 8,922,496 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• 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 3/0416 Control or interface arrangements specially adapted for digitisers
• 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 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: G06F 3/04883 for inputting data by handwriting, e.g. gesture or text

Abstract

An apparatus and a method for controlling a touch panel are disclosed herein, the apparatus includes an object detection module and an adjusting device. The object detection module can detect a position of at least one object contacting the touch panel. A position analyzer recognizes position of the object and the adjusting device can set the touch panel to a predetermined position according to the result recognized by the position analyzer.

Claims

1. A multi-touch detection method for a touch panel, wherein the touch panel comprises a first conductive layer and an overlapping second conductive layer, the first conductive layer having a plurality of first electrodes disposed along a first-axis direction, and the second conductive layer having a plurality of second electrodes disposed along a second-axis direction, the multi-touch detection method comprising:

sensing the second electrodes to obtain a first voltage function when a first voltage is provided to the first electrodes;

sensing the second electrodes to obtain a second voltage function when the first voltage is provided to a first portion of the first electrodes and is not provided to a second portion of the first electrodes; and

calculating positions of a first contact point and a second contact point in the second-axis direction by the first and the second voltage functions.

2. The multi-touch detection method as claimed in claim 1, wherein the first conductive layer and the second conductive layer are anisotropic in electric conductivity.

3. The multi-touch detection method as claimed in claim 2, wherein the first conductive layer and the second conductive layer each have a low impedance direction and a high impedance direction, the low impedance direction of the second conductive layer is the first-axis direction, and the low impedance direction of the first conductive layer is the second-axis direction.

4. The multi-touch detection method as claimed in claim 2, wherein the first conductive layer and the second conductive layer are conductive films formed by carbon nanotubes substantially arranged in parallel.

5. The multi-touch detection method as claimed in claim 1, wherein the first-axis direction and the second-axis direction are substantially perpendicular to each other.

6. The multi-touch detection method as claimed in claim 1, further comprising:

when the second electrodes are sequentially sensed, providing a second voltage to the second electrodes which are not sensed.

7. The multi-touch detection method as claimed in claim 1, further comprising:

when the first voltage is provided to the first portion of the first electrodes, providing a second voltage to the second portion of the first electrodes.

8. The multi-touch detection method as claimed in claim 1, wherein the step of calculating the positions of the first contact point and the second contact point in the second-axis direction by the first and the second voltage functions comprises:

providing a correction parameter r;

deeming a position corresponding to an extreme value of the second voltage function as the position of the first contact point in the second-axis direction;

calculating an equation P2=P(1+2)−

r×

P1 to obtain a third voltage function P2, wherein P(1+2) represents the first voltage function, and P1 represents the second voltage function; and

deeming a position corresponding to an extreme value of the third voltage function P2 as the position of the second contact point in the second-axis direction.

9. The multi-touch detection method as claimed in claim 8, wherein the step of providing the correction parameter r comprises:

providing a lookup table; and

searching the lookup table to obtain and provide the correction parameter r according to a position of the first contact point in the first-axis direction.

10. The multi-touch detection method as claimed in claim 1, wherein the step of calculating the positions of the first contact point and the second contact point in the second-axis direction by the first and the second voltage functions comprises:

deeming a position corresponding to an extreme value of the first voltage function as a central position;

deeming a position corresponding to an extreme value of the second voltage function as the position of the first contact point in the second-axis direction; and

calculating an equation p2=2×

pm−

p1 to obtain a position of the second contact point p2, wherein pm represents the central position, and p1 represents the position of the first contact point.

11. The multi-touch detection method as claimed in claim 1, further comprising:

sensing the first electrodes to obtain a fourth voltage function when a second voltage is provided to the second electrodes; and

respectively deeming positions corresponding to two extreme values of the fourth voltage function as positions of the first contact point and the second contact point in the first-axis direction.

12. The multi-touch detection method as claimed in claim 11, further comprising:

when the first electrodes are sequentially sensed, providing the first voltage to the first electrodes which are not sensed.

13. A multi-touch detection method for a touch panel, wherein the touch panel comprises a first conductive layer and an overlapping second conductive layer, the first conductive layer having a plurality of first electrodes disposed along a first-axis direction, the second conductive layer having a plurality of second electrodes and third electrodes along a second-axis direction, and the second electrodes and the third electrodes are respectively disposed at different sides of the second conductive layer along the first-axis direction, the multi-touch detection method comprising:

sensing the second electrodes to obtain a first voltage function when a first voltage is provided to a first portion of the first electrodes and is not provided to a second portion of the first electrodes;

sensing the third electrodes to obtain a second voltage function when the first voltage is provided to the second portion of the first electrodes and is not provided to the first portion of the first electrodes;

deeming a position corresponding to an extreme value of the first voltage function as a position of the first contact point in the second-axis direction; and

deeming a position corresponding to an extreme value of the second voltage function as a position of the second contact point in the second-axis direction.

14. The multi-touch detection method as claimed in claim 13, wherein the first conductive layer and the second conductive layer are anisotropic in electric conductivity.

15. The multi-touch detection method as claimed in claim 14, wherein the first conductive layer and the second conductive layer each have a low impedance direction and a high impedance direction, the low impedance direction of the second conductive layer is the first-axis direction, and the low impedance direction of the first conductive layer is the second-axis direction.

16. The multi-touch detection method as claimed in claim 14, wherein the first conductive layer and the second conductive layer are conductive films formed by carbon nanotubes arranged substantially in parallel.

17. The multi-touch detection method as claimed in claim 13, wherein the first-axis direction and the second-axis direction are substantially perpendicular to each other.

18. The multi-touch detection method as claimed in claim 13, further comprising:

when the second electrodes and the third electrodes are sequentially sensed, providing a second voltage to the second electrodes and the third electrodes which are not sensed.

19. The multi-touch detection method as claimed in claim 13, further comprising:

when the first voltage is provided to the first portion of the first electrodes, providing a second voltage to the second portion of the first electrodes.

20. The multi-touch detection method as claimed in claim 13, further comprising:

sensing the first electrodes to obtain a third voltage function when a second voltage is provided to at least one of the second electrodes and the third electrodes; and

respectively deeming positions corresponding to two extreme values of the third voltage function as positions of the first contact point and the second contact point in the first-axis direction.

21. The multi-touch detection method as claimed in claim 20, further comprising:

when the first electrodes are sequentially sensed, providing the first voltage to the first electrodes which are not sensed.