In-cell touch sensor touch area enhancing algorithm

• US 8,674,956 B2
• Filed: 06/13/2011
• Issued: 03/18/2014
• Est. Priority Date: 06/13/2011
• Status: Active Grant

• Current Assignee: InnoLux Corporation
• Original Assignee: InnoLux Corporation
• Inventors: Sumi, Naoki, Matsui, Yoshikazu
• Primary Examiner(s): FRY, MATTHEW A
• Application Number:
  US13/158,924
• Publication Number:
  US 20120313861A1
• Time in Patent Office: 1,009 Days
• Field of Search: 345173-174, 345/178, 178/18.01, 178/18.02, 178/18.06
• 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 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A touch detection method includes: scanning the row electrodes or the column electrodes in sequence to obtain touch data of the touch sensor; labeling a plurality of coordinates as a touch image according to the touch data; mirror copying the touch data of the touch image corresponding to at least one column electrode and at least one row electrode which are adjacent to an edge of the pixel active area in the x-direction and the y-direction, respectively, to at least one corresponding location which is outside of the touch sensor active area with respect to the edge of the pixel active area; calculating a location (x_ave, y_ave) of the central point of the touch image by a weighted average; and outputting the location (x_ave, y_ave) of the central point of the touch image.

Claims

1. A touch detection method, comprising:

scanning row electrodes or column electrodes of a touch sensor in sequence to obtain touch data of the touch sensor;

labeling a plurality of coordinates as a touch image according to the touch data;

mirror copying the touch data of the touch image corresponding to at least one column electrode and at least one row electrode which are adjacent to an edge of the pixel active area in the x-direction and the y-direction, respectively, to at least one corresponding location which is outside of the touch sensor active area with respect to the edge of the pixel active area;

calculating a location (x_ave, y_ave) of the central point of the touch image by a weighted average; and

outputting the location (x_ave, y_ave) of the central point of the touch image,

wherein in the case where touch data of the touch image corresponding to only the first column electrode from the edge of the pixel active area and only the first row electrode from the edge of the pixel active area are mirror-copied, the location (x_ave, y_ave) of the central point of the touch image is calculated by the following formula, wherein V_x,y is the touch data that is linked to capacitance of a touch level at a location (x, y), M is the number of column electrodes, and N is the number of row electrodes;

2. The touch detection method as claimed in claim 1, wherein the distance between the corresponding location which is outside of the touch sensor active area and the edge of the pixel active area is equal to the distance between the location where the touch data is copied and the edge of the pixel active area.

3. The touch detection method as claimed in claim 1, wherein the calculation formula for 4 corners of the coordinate system is considered as a special case, wherein:

x=y=1, then X_mod=y_mod=0, and k=4;

x=M, y=1, then x_mod=4M+4, y_mod=0, and k=4;

x=1, y=N, then x_mod=0, y_mod=4N+4, and k=4; and

x=M, y=N, then x_mod=4M+4, y_mod=4N+4, and k=4.

4. A touch sensor, comprising:

a scanning device scanning row electrodes or column electrodes in sequence to obtain touch data of the touch sensor; and

a calculation device comprising;

a labeling module labeling a plurality of coordinates as a touch image according to the touch data;

a calculation module mirror copying the touch data of the touch image corresponding to at least one column electrode and at least one row electrode which are adjacent to an edge of the pixel active area in the x-direction and the y-direction, respectively, to at least one corresponding location which is outside of the touch sensor active area with respect to the edge of the pixel active area, and calculating a location (x_ave, y_ave) of the central point of the touch image by a weighted average; and

an output module outputting the location (x_ave, y_ave) of the central point of the touch image,

wherein in the case where touch data of the touch image corresponding to only the first column electrode from the edge of the pixel active area and only the first row electrode from the edge of the pixel active area are mirror-copied, the location (x_ave, y_ave) of the central point of the touch image is calculated by the following formula, wherein V_x,y is the touch data that is linked to capacitance of a touch level at a location (x, y), M is the number of column electrodes, and N is the number of row electrodes;

5. The touch sensor as claimed in claim 4, wherein the distance between the corresponding location which is outside of the touch sensor active area and the edge of the pixel active area is equal to the distance between the location where the touch data is copied and the edge of the pixel active area.

6. The touch sensor as claimed in claim 4, wherein the calculation formula for 4 corners of the coordinate system is considered as a special case, wherein:

if x=y=1, then x_mod=y_mod=0, and k=4;

if x=M, y=1, then x_mod=4M+4, y_mod=0, and k=4;

if x=1, y=N, then x_mod=0, y_mod=4N+4, and k=4; and

if x=M, y=N, then x_mod=4M+4, y_mod=4N+4, and k=4.