Method and device for reducing poor linearity in location detection

• US 9,575,596 B2
• Filed: 10/05/2016
• Issued: 02/21/2017
• Est. Priority Date: 12/28/2012
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: Yeh, Shang-Tai
• Primary Examiner(s): Haley, Joseph
• Assistant Examiner(s): KIYABU, KARIN A
• Application Number:
  US15/286,008
• Publication Number:
  US 20170024079A1
• Time in Patent Office: 139 Days
• US Class Current: 1/1
• 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

Abstract

The changes of capacitances of a plurality of detecting locations on a touch screen are detected for determining a profile corresponding to each external object approaching or touching the touch screen. Then the location of each external object is generated separately by two or four values in the corresponding profile.

Claims

1. A method for location detection of a touch screen comprising:

detecting changes in capacitances of a plurality of detecting locations on the touch screen, wherein each change in capacitances corresponds to a coordinate; and

determining a profile corresponding to each external object based on the changes in capacitances of the detecting locations on the touch screen, and generating a coordinate data of each external object based on two values in the corresponding profile,

wherein the coordinate data is (C1×

X1+C3×

X3)/(C1+C3), wherein X1 and X3 are the coordinates for C1 and C3, respectively, and C1 and C3 correspond to two values in the profile of each external object, respectively, wherein C1 is the value immediately preceding a largest value C2 in the profile, C3 is the value immediately following the largest value C2 in the profile.

2. A device for location detection of a touch screen comprising:

a detecting unit for detecting changes in capacitances of a plurality of detecting locations on the touch screen, wherein each change in capacitances corresponds to a coordinate; and

a control unit for determining a profile corresponding to each external object based on the changes in capacitances of the detecting locations on the touch screen, and generating a coordinate data of each external object is based on two values in the corresponding profile,

wherein the coordinate data is (C1×

X1+C3×

X3)/(C1+C3), wherein X1 and X3 are the coordinates for C1 and C3, respectively, and C1 and C3 correspond to two values in the profile of each external object, respectively, wherein C1 is the value immediately preceding a largest value C2 in the profile, C3 is the value immediately following the largest value C2 in the profile.