Positioning method for touch display panel

• US 8,963,879 B2
• Filed: 09/14/2012
• Issued: 02/24/2015
• Est. Priority Date: 07/03/2012
• Status: Active Grant

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: E Ink Holdings Incorporated
• Inventors: Chen, Wei-Hao, Lin, Chin-Yi
• Primary Examiner(s): JOHNSON, ALLISON WALTHALL
• Application Number:
  US13/615,643
• Publication Number:
  US 20140009433A1
• Time in Patent Office: 893 Days
• Field of Search: 345/174, 178/18.06
• 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 3/0446 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 positioning method for a touch display panel is provided. The touch display panel includes a touch panel and a display panel. The display panel is disposed on the touch panel, and sensing points and reference positions are set on the touch panel. In the method, pressures with different values are repeatedly applied to each reference position; under the pressures with the different values, average capacitance values of the reference positions corresponding to the sensing points are calculated. When an object touches the display panel, the sensing points of the touch panel correspondingly generate second capacitance values. Under a touch pressure value, the average capacitance values of the reference positions corresponding to the sensing points are selected. The second capacitance values and the average capacitance values of the reference positions corresponding to the sensing points under the touch pressure value are used to calculate a touch position of the object.

Claims

1. A positioning method for a touch display panel comprising a display panel and a touch panel, the display panel being disposed on the touch panel, wherein the touch panel has a plurality of sensing points thereon and contains a plurality of reference positions defined by a plurality of x-axes and a plurality of y-axes, the x-axes and the y-axes being alternately arranged in a matrix manner, the sensing points being distributed on the reference positions, the positioning method comprising:

applying pressures with different values to each of the reference positions repeatedly, detecting a plurality of first capacitance values generated by the sensing points under the pressures with the different values, performing a calculation operation on the first capacitance values respectively corresponding to the reference positions under the same pressure value, and calculating a plurality of average capacitance values of the reference positions corresponding to the sensing points under the pressures with the different values;

when an object touches the display panel, correspondingly generating a plurality of second capacitance values by the sensing points of the touch panel;

comparing the second capacitance values with the average capacitance values under the pressures with the different values, and selecting the average capacitance values of the reference positions corresponding to the sensing points under a touch pressure value of the pressures with the different values; and

using the second capacitance values and the average capacitance values of the reference positions corresponding to the sensing points under the touch pressure value to calculate a touch position of the object,

wherein the step of comparing the second capacitance values with the average capacitance values under the pressures with the different values comprises;

selecting the average capacitance values of the reference positions in a first target region around one of the sensing points having a maximum second capacitance value of the second capacitance values;

using a formula comprising parameters of the second capacitance values of the touch position and the average capacitance values of the reference positions in the first target region under the pressures with the different values to at least calculate a third capacitance value and a fourth capacitance value of the first target region respectively corresponding to two of the pressures with the different values; and

selecting a minimum value from the third and fourth capacitance values of the first target region to obtain the average capacitance values of the reference positions corresponding to the sensing points under the touch pressure value.

2. The positioning method for the touch display panel as recited in claim 1, further comprising:

after selecting the average capacitance values of the reference positions in the first target region under the pressures with the different values, selecting the average capacitance values of the reference positions in a second target region around one of the sensing points having a second largest second capacitance value of the second capacitance values under the pressures with the different values, wherein the second target region and the first target region are partially overlapped;

using a formula comprising parameters of the second capacitance values of the touch position and the average capacitance values of the reference positions in the second target region under the pressures with the different values to at least calculate a fifth capacitance value and a sixth capacitance value respectively corresponding to two of the pressures with the different values; and

selecting a minimum value from the third, fourth, fifth, and sixth capacitance values to obtain the average capacitance values of the reference positions corresponding to the sensing points under the touch pressure value.

3. The positioning method for the touch display panel as recited in claim 2, wherein the formula comprising the parameters of the second capacitance values of the touch position and the average capacitance values of the reference positions in the first target region or the second target region under the pressures with the different values is:

M1=(C₁-table_—

C₁)^2+(C₂-table_—

C₂)^2+(C₃-table_—

C₃)^2+ . . . +(C_n-table_—

C_n)^2,

n≧

1, wherein n is the number of the sensing points, C₁˜

C_n are the second capacitance values of the sensing points corresponding to the reference positions, table_C₁˜

table_C_n are the average capacitance values of the reference positions corresponding to the sensing points, and M1 is a capacitance value corresponding to each of the pressures with the different values.

4. The positioning method for the touch display panel as recited in claim 2, wherein the formula comprising the parameters of the second capacitance values of the touch position and the average capacitance values of the reference positions in the first target region or the second target region under the pressures with the different values is:

M1=abs(C₁-table_—

C₁)+abs(C₂-table_—

C₂)+abs(C₃-table_—

C₃)+ . . . +abs(C_n-table_—

C_n),

n≧

1, wherein n is the number of the sensing points, C₁˜

C_n are the second capacitance values of the sensing points corresponding to the reference positions, table_C₁˜

table_C_n are the average capacitance values of the reference positions corresponding to the sensing points, and M1 is a capacitance value corresponding to each of the pressures with the different values.

5. The positioning method for the touch display panel as recited in claim 1, wherein the step of using the second capacitance values and the average capacitance values of the reference positions corresponding to the sensing points under the touch pressure value to calculate the touch position of the object comprises:

selecting the average capacitance values of the reference positions corresponding to the sensing points in a third target region around one of the sensing points having a maximum second capacitance value of the second capacitance values under the touch pressure value;

using a formula comprising parameters of the second capacitance values of the touch position and the average capacitance values of the reference positions in the third target region under the touch pressure value to at least calculate a third capacitance value and a fourth capacitance value of the third target region respectively corresponding to two different values; and

selecting a minimum value from the third and fourth capacitance values of the third target region to obtain the touch position of the object.

6. The positioning method for the touch display panel as recited in claim 5, further comprising:

after selecting the average capacitance values of the reference positions corresponding to the sensing points in the third target region under the touch pressure value, selecting the average capacitance values of the reference positions corresponding to the sensing points in a fourth target region around one of the sensing points having a second largest second capacitance value of the second capacitance values under the touch pressure value, wherein the fourth target region and the third target region are partially overlapped;

using a formula comprising parameters of the second capacitance values of the touch position and the average capacitance values of the reference positions in the fourth target region under the touch pressure value to at least calculate a fifth capacitance value and a sixth capacitance value respectively corresponding to two different values; and

selecting a minimum value from the third, fourth, fifth, and sixth capacitance values to obtain the touch position of the object.

7. The positioning method for the touch display panel as recited in claim 6, wherein the formula comprising the parameters of the second capacitance values of the touch position and the average capacitance values of the reference positions in the third target region or the fourth target region under the touch pressure value is:

M2=sqrt((C₁-table_—

C₁)^2+(C₂-table_—

C₂)^2+(C₃-table_—

C₃)^2+ . . . +(C_n-table_—

C_n)^2),

n≧

1, wherein n is the number of the sensing points, C₁˜

C_n are the second capacitance values of the sensing points corresponding to the reference positions, table_C₁˜

table_C_n are the average capacitance values of the reference positions corresponding to the sensing points, and M2 is a capacitance value under the touch pressure value.

8. The positioning method for the touch display panel as recited in claim 6, wherein the formula comprising the parameters of the second capacitance values of the touch position and the average capacitance values of the reference positions in the third target region or the fourth target region under the touch pressure value is:

M2=abs(C₁-table_—

C₁)+abs(C₂-table_—

C₂)+abs(C₃-table_—

C₃)+ . . . +abs(C_n-table_—

C_n),

n≧

1, wherein n is the number of the sensing points, C₁˜

C_n are the second capacitance values of the sensing points corresponding to the reference positions, table_C₁˜

table_C_n are the average capacitance values of the reference positions corresponding to the sensing points, and M2 is a capacitance value under the touch pressure value.

9. The positioning method for the touch display panel as recited in claim 6, further comprising:

applying different weights respectively to the third, fourth, fifth, and sixth capacitance values.