Touch panel and differential detection method for same

• US 8,766,947 B2
• Filed: 03/10/2011
• Issued: 07/01/2014
• Est. Priority Date: 03/17/2010
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: InnoLux Corporation
• Inventors: Cheng, Chien-Yung, Shih, Po-Sheng, Chen, Po-Yang
• Primary Examiner(s): Mengistu, Amare
• Assistant Examiner(s): LAM, VINH TANG
• Application Number:
  US13/044,560
• Publication Number:
  US 20110227863A1
• Time in Patent Office: 1,209 Days
• Field of Search: 345173-184, 178 1801- 2004
• US Class Current: 345/174
• 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
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells

Abstract

A touch panel and a differential detection method thereof are disclosed. A controller provides a driving signal to the i-th scan electrode. During providing the driving signal to the i-th scan electrode, the controller senses the feature difference value between two neighboring sensing electrodes within the plural sensing electrodes, and senses the feature difference value ΔCi between the k-th sensing electrode within the sensing electrodes and a reference feature value, in which the feature difference values between the j-th sensing electrode and the (j+1)-th sensing electrode is represented by ΔC(i,j). The controller set the feature value of a base sensing point within a plurality of sensing points of the touch panel as a base feature value, and use the base feature value, the feature difference values ΔCi and the feature difference values ΔC(i,j) to calculate the feature values of the sensing points.

Claims

1. A differential detection method of a touch panel, wherein the touch panel has a plurality of scan electrodes and a plurality of sensing electrodes respectively along a first axial direction and a second axial direction;

the differential detection method comprising;

selecting the i-th scan electrode within the scan electrodes so as to provide a driving signal to the i-th scan electrode, wherein i is integer;

sensing a feature difference value Δ

C(i, j), where C is a capacitance, current or voltage, between the j-th sensing electrode within the sensing electrodes and another neighbouring sensing electrode during providing the driving signal to the i-th scan electrode, wherein j is an integer;

sensing a feature difference value Δ

Ci, where Ci is a capacitance, current or voltage, between the k-th sensing electrode within the sensing electrodes and a reference feature value during providing the driving signal to the i-th scan electrode, wherein k is an integer;

setting the feature value of a base sensing point within a plurality of sensing points of the touch panel as a base feature value; and

using the base feature value, the feature difference values Δ

Ci and the feature difference values Δ

C(i,j) to calculate the feature values of the sensing points,

wherein the above-mentioned step of calculating the feature values of a plurality of sensing points of the touch panel comprises;

calculating Δ

C[i]=Δ

Ci−

Δ

C(i+1), wherein Δ

C[i] represents the feature difference value between the i-th scan electrode and the (i+1)-th scan electrode;

if the base sensing point is located at the i-th row, using the base feature value to calculate C(i+1,j)=C(i,j)−

Δ

C[i] or C(i−

1,j)=C(i,j)+Δ

C[i], wherein C(i,j) represents the feature value of the sensing point with the i-th column and the j-th row within the sensing points; and

calculating C(i,j+1)=C(i,j)−

Δ

C(i,j) or C(i,j−

1)=C(i,j)+Δ

C(i,j).

2. The differential detection method of a touch panel as claimed in claim 1, wherein the feature value of the sensing points is capacitance value, current value or voltage value.

3. The differential detection method of a touch panel as claimed in claim 1, further comprising:

calculating the difference between the minimum feature value within the feature values of all the sensing points on the i-th scan line and the base feature value, and taking the difference as a compensation value; and

adjusting the feature values of all the sensing points on the i-th scan line according to the compensation value.

4. The differential detection method of a touch panel as claimed in claim 1, further comprising:

calculating an average feature value of all the sensing points on the i-th scan line;

calculating the difference between the average feature value and the base feature value, and taking the difference as a compensation value; and

adjusting the feature values of all the sensing points on the i-th scan line according to the compensation value.

5. The differential detection method of a touch panel as claimed in claim 1, wherein the step of sensing the feature difference value Δ

Ci comprises;

sensing the feature difference value Δ

Ci between the k-th sensing electrode and a dummy sensing electrode of the touch panel.

6. The differential detection method of a touch panel as claimed in claim 1, wherein the step of sensing the feature difference value Δ

Ci comprises;

sensing the feature difference value Δ

Ci between the k-th sensing electrode and a reference capacitor.

7. The differential detection method of a touch panel as claimed in claim 1, wherein the k-th sensing electrode mentioned in the step of sensing the feature difference value Δ

Ci is an edge electrode within the sensing electrodes.

8. The differential detection method of a touch panel as claimed in claim 1, wherein in the step of selecting the i-th scan electrode within the scan electrodes, the next scan electrode is sequentially selected.

9. The differential detection method of a touch panel as claimed in claim 1, further comprising:

if within the sensing points, the feature value of a first sensing point is greater than the feature values of all the neighbouring sensing points adjacent to the first sensing point, deciding the first sensing point as a touch point.

10. A touch panel, comprising:

a first conductive layer;

a plurality of scan electrodes, disposed at a side of the first conductive layer along a first axial direction;

a second conductive layer;

a plurality of sensing electrodes, disposed at a side of the second conductive layer along a second axial direction; and

a controller, selecting the i-th scan electrode within the scan electrodes so as to provide a driving signal to the i-th scan electrode, wherein during providing the driving signal to the i-th scan electrode, the controller senses the feature difference value Δ

C(i, j), where C is a capacitance, current or voltage, between the j-th sensing electrode within the sensing electrodes and another neighbouring sensing electrode;

during providing the driving signal to the i-th scan electrode, the controller senses the feature difference value Δ

Ci, where Ci is a capacitance, current or voltage, between the k-th sensing electrode within the sensing electrodes and a reference feature value, the above-mentioned i, j and k are integers;

the controller sets the feature value of a base sensing point within a plurality of sensing points of the touch panel as a base feature value; and

the controller uses the base feature value, the feature difference values Δ

Ci and the feature difference values Δ

C(i,j) to calculate the feature values of the sensing points,

wherein the controller calculates Δ

C[i]=Δ

Ci−

Δ

C(i+1), wherein Δ

C[i] represents the feature difference value between the i-th scan electrode and the (i+1)-th scan electrode;

if the base sensing point is located at the j-th row, the controller uses the base feature value to calculate C(i+1,j)=C(i,j)−

Δ

C[i] or C(i−

1,j)=C(i,j)+Δ

C[i], wherein C(i,j) represents the feature value of the sensing point with the i-th column and the j-th row within the sensing points; and

the controller calculates C(i,j+1)=C(i,j)−

Δ

C(i,j) or C(i,j−

1)=C(i,j)+Δ

C(i,j).

11. The touch panel as claimed in claim 10, wherein the feature value of the sensing points is capacitance value, current value or voltage value.

12. The touch panel as claimed in claim 10, wherein the controller further calculates the difference between the minimum feature value within the feature values of all the sensing points on the i-th scan line and the base feature value, and takes the difference as a compensation value;

and the controller adjusts the feature values of all the sensing points on the i-th scan line according to the compensation value.

13. The touch panel as claimed in claim 10, wherein the controller further calculates an average feature value of all the sensing points on the i-th scan line;

the controller calculates the difference between the average feature value and the base feature value and takes the difference as a compensation value; and

the controller adjusts the feature values of all the sensing points on the i-th scan line according to the compensation value.

14. The touch panel as claimed in claim 10, wherein the controller senses the feature difference value Δ

Ci between the k-th sensing electrode and a dummy sensing electrode of the touch panel.

15. The touch panel as claimed in claim 10, wherein the controller senses the feature difference value Δ

Ci between the k-th sensing electrode and a reference capacitor.

16. The touch panel as claimed in claim 10, wherein the k-th sensing electrode is an edge electrode within the sensing electrodes.

17. The touch panel as claimed in claim 10, wherein the controller sequentially selects the next scan electrode.

18. The touch panel as claimed in claim 10, wherein the controller further compares the feature values of the sensing points, if within the sensing points, the feature value of a first sensing point is greater than the feature values of all the sensing points adjacent to the first sensing point, the controller decides the first sensing point as a touch point.

19. The touch panel as claimed in claim 10, wherein at least one of the first conductive layer and second conductive layer is composed of carbon nanotube film.

20. The touch panel as claimed in claim 10, wherein second conductive layer is a indium tin oxide film.

21. The touch panel as claimed in claim 10, further comprising:

an insulating layer structure, disposed between the first conductive layer and the second conductive layer.