METHOD AND DRIVING APPARATUS FOR IDENTIFYING SENSING VALUE OF TOUCH PANEL

• US 20120056851A1
• Filed: 09/06/2011
• Published: 03/08/2012
• Est. Priority Date: 09/07/2010
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: Chi Mei Innolux Corporation (InnoLux Corporation)
• Inventors: CHEN, PO-YANG, SHIH, PO-SHENG, CHENG, CHIEN-YUNG
• Granted Patent: US 8,884,915 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

A method and a driving apparatus for identifying a sensing value of a touch panel are provided. The method includes sensing a plurality of electrodes of the touch panel to obtain raw data and baseline data of each electrode, wherein an electrode S_i denotes an i^th electrode of the electrodes in the touch panel. A sensing value of the electrode S_i is calculated in accordance with the raw data and the baseline data of the electrode S_i. When sensing values of all electrodes S_i are smaller than a threshold value, the baseline data of the electrode S_i is updated in accordance with the raw data of the electrode S_i. When a sensing value of any one electrode S_i of the electrodes is larger than the threshold value, the baseline data of the electrodes is suspended from being updated.

Claims

1. A method for identifying a sensing value of a touch panel, comprising:

sensing a plurality of electrodes of the touch panel to obtain raw data and baseline data of each electrode, wherein an electrode S_i denotes an ith electrode of the electrodes of the touch panel;

calculating a sensing value of the electrode S_i in accordance with the raw data and the baseline data of the electrode S_i;

when sensing values of all the electrodes S_i are smaller than a threshold value, updating the baseline data of the electrode S_i in accordance with the raw data of the electrode S_i; and

when a sensing value of any one electrode S_i of the electrodes is larger than the threshold value, suspending updating the baseline data of the electrodes.

2. The method according to claim 1, wherein the step of updating the baseline data of the electrode S_i comprises:

calculating BL_i(n)=(N−

1)×

BL_i(n−

1)+(N)×

RD_i, wherein N is a constant ranging from 0 to 1, RD_i denotes the raw data of the electrode S_i, BL_i(n−

1) denotes baseline data obtained before the electrode S_i is updated, and BL_i(n) denotes baseline data obtained after the electrode Si is updated.

3. The method according to claim 1, wherein the step of calculating the sensing value of the electrode Si comprises:

calculating a difference between the raw data and the baseline data of the electrode Si, so as to take the difference to be served as the sensing value of the electrode Si.

4. The method according to claim 1, wherein the touch panel comprises a conductive layer with anisotropic conductivity, a low impedance direction of the conductive layer is a first axial direction, two opposite side edges of the conductive layer along the first axial direction are a first side and a second side respectively, and the electrodes are disposed at the first side and the second side.

5. The method according to claim 4, wherein the conductive layer is a carbon nano-tube (CNT) thin film.

6. A driving apparatus of a touch panel, comprising:

a selector, connected to a plurality of electrodes of the touch panel, wherein an electrode Si denotes an ith electrode of the electrodes of the touch panel;

a sensing circuit, connected to the selector, wherein the sensing circuit senses the electrodes one by one through a switching operation of the selector, and obtains raw data and baseline data of each electrode Si; and

a controller, connected to the sensing circuit, wherein the controller calculates a sensing value of the electrode Si in accordance with the raw data and the baseline data of the electrode Si;

when sensing values of all the electrodes Si are smaller than a threshold value, the controller updates the baseline data of the electrode Si in accordance with the raw data of the electrode Si; and

when a sensing value of any one electrode Si of the electrodes is larger than the threshold value, the controller suspends updating the baseline data of the electrodes.

7. The driving apparatus of the touch panel according to claim 6, wherein if RDi denotes the raw data of the electrode Si, BLi(n−

1) denotes baseline data obtained before the electrode Si is updated, and BLi(n) denotes baseline data obtained after the electrode Si is updated, the controller calculates BLi(n)=(N−

1)×

BLi(n−

1)+(N)×

RDi, so as to update the baseline data of the electrode Si, wherein N is a constant ranging from 0 to 1.

8. The driving apparatus of the touch panel according to claim 6, wherein the controller calculates a difference between the raw data and the baseline data of the electrode Si, so as to take the difference to be served as the sensing value of the electrode Si.

9. The driving apparatus of the touch panel according to claim 6, wherein the touch panel comprises a conductive layer with anisotropic conductivity, a low impedance direction of the conductive layer is a first axial direction, two opposite side edges of the conductive layer along the first axial direction are a first side and a second side respectively, and the electrodes are disposed at the first side and the second side.

10. The driving apparatus of the touch panel according to claim 9, wherein the conductive layer is a carbon nano-tube (CNT) thin film.

11. A method for identifying a sensing value of a touch panel, wherein two opposite side edges of the touch panel along a first axial direction are a first side and a second side respectively, the touch panel comprises a plurality of electrode pairs, the electrode pairs respectively comprise a first electrode and a second electrode, the first electrodes are disposed at the first side of the touch panel, and the second electrodes are disposed at the second side of the touch panel, the method comprising:

sensing the electrode pairs of the touch panel to obtain raw data and baseline data of each electrode, wherein an electrode Si denotes one of the first electrodes and the second electrodes of the touch panel;

calculating a sensing value of the electrode Si in accordance with the raw data and the baseline data of the electrode Si;

when a sum of a sensing value of a first electrode and a sensing value of a second electrode of the electrode pairs is smaller than a threshold value, updating the baseline data of the electrode Si in accordance with the raw data of the electrode Si; and

when the sum of the sensing value of the first electrode and the sensing value of the second electrode of any one of the electrode pairs is larger than the threshold value, suspending updating the baseline data of the electrode pairs.

12. The method according to claim 11, wherein the step of updating the baseline data of the electrode Si comprises:

calculating BLi(n)=(N−

1)×

BLi(n−

1)+(N)×

RDi, wherein N is a constant ranging from 0 to 1, RDi denotes the raw data of the electrode Si, BLi(n−

1) denotes baseline data obtained before the electrode Si is updated, and BLi(n) denotes baseline data obtained after the electrode Si is updated.

13. The method according to claim 11, wherein the step of calculating the sensing value of the electrode Si comprises:

calculating a difference between the raw data and the baseline data of the electrode Si, so as to take the difference to be served as the sensing value of the electrode Si.

14. The method according to claim 11, wherein the touch panel comprises a conductive layer with anisotropic conductivity, and a low impedance direction of the conductive layer is the first axial direction.

15. The method according to claim 14, wherein the conductive layer is a carbon nano-tube (CNT) thin film.

16. The method according to claim 11, wherein in the electrode pairs, a direction from the first electrodes to the second electrodes is the first axial direction.