SINGLE-SURFACE POSITION SENSOR AND POSITIONING METHD THEREOF

• US 20180267650A1
• Filed: 02/11/2015
• Published: 09/20/2018
• Est. Priority Date: 01/21/2015
• Status: Active Grant

• Current Assignee: Peking University
• Original Assignee: Peking University
• Inventors: ZHANG, Haixia, SHI, Mayue, CHEN, Haotian, ZHANG, Jinxin, HAN, Mengdi, SU, Zongming, MENG, Bo, CHENG, Xiaoliang
• Granted Patent: US 10,712,893 B2
• Time in Patent Office: Days
• CPC Class Codes: G01B 7/003 for measuring position, not involving coordinate determination coordinate measuring G01B7/004
• CPC Class Codes: G01D 5/20 by varying inductance, e.g. by a movable armature
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A single-surface position sensor and a positioning method thereof are disclosed. The single-surface position sensor comprises a substrate layer (1) and induction electrodes (3, 4, 5, 6); the induction electrodes (3, 4, 5, 6) are located on the substrate layer (1); the sensor further comprises a friction layer (2); the friction layer (2) is located on the substrate layer (1); the friction layer (2) is located among the induction electrodes (3, 4, 5, 6); the individual induction electrodes (3, 4, 5, 6) are grounded through the same load resistors, so that an object under test contacts with and is separated from the friction layer (2) at least one time and different voltage outputs are generated across the various load resistors; a position of the object under test is determined by analyzing a ratio of the voltages of all the electrodes (3, 4, 5, 6); the single-surface position sensor is an active sensor and reduce energy consumption as compared with traditional sensors; the single-surface position sensor can be manufactured into a flexible transparent thin film and can be widely applied to portable electronic devices and wearable devices; and the single-surface position sensor is simple in process and low in cost.

Claims

1. A single-surface position sensor, comprising:

a substrate layer; and

induction electrodes located on the substrate layer.

2. The single-surface position sensor according to claim 1, further comprising a friction layer located on the substrate layer and located among the induction electrodes.

3. The single-surface position sensor according to claim 1, further comprising a friction layer located under the substrate layer.

4. The single-surface position sensor according to claim 1, wherein a number of the induction electrodes is one or more.

5. The single-surface position sensor according to claim 1, wherein individual induction electrodes are grounded through load resistors which are the same, such that an object under test contacts with or is separated from the friction layer at least one time, different voltage outputs are generated across respective load resistors;

and a position of the object under test is determined by analyzing a ratio of voltages of the respective electrodes.

6. A positioning method of a single-surface position sensor adapted to the single-surface position sensor according to claim 1, comprising steps of:

dividing an operation region of the sensor into a plurality of test points, and performing an induction test on each test point in order, to obtain peak voltage data of respective electrodes corresponding to each test point;

fitting out a transverse fitting curve of each row of test points according to peak voltage data of the respective electrodes corresponding to each row of test points, and fitting out a longitudinal fitting curve of each column of test points according to peak voltage data of the respective electrodes corresponding to each column of test points;

connecting or fitting points corresponding to transverse electrode peak voltage ratios of a position under test on various transverse fitting curves, to obtain a curve L₁, and connecting or fitting points corresponding to longitudinal electrode peak voltage ratios of the position under test on various longitudinal fitting curves, to obtain a curve L₂; and

determining a coordinate of a point of intersection of the curve L₁ and the curve L₂ as a coordinate of the position under test.

7. The positioning method of a single-surface position sensor according to claim 6, wherein the step of dividing an operation region of the sensor into a plurality of test points and performing an induction test on each test point in order to obtain peak voltage data of respective electrodes corresponding to each test point comprises:

dividing the operation region of the sensor into n*n regions in a transverse direction and a longitudinal direction, and performing induction tests on n² test points in order, to obtain peak voltages of four electrodes corresponding to each test point; and

calculating a transverse electrode peak voltage ratio and a longitudinal electrode peak voltage ratio corresponding to each test point according to the peak voltages of four electrodes corresponding to each test point.

8. The positioning method of a single-surface position sensor according to claim 7, wherein the step of fitting out the transverse fitting curve of each row of test points according to peak voltage data of the respective electrodes corresponding to each row of test points, and fitting out the longitudinal fitting curve of each column of test points according to peak voltage data of the respective electrodes corresponding to each column of test points comprises:

fitting the transverse electrode peak voltage ratio data corresponding to each test point in each row of test points by a set transverse fitting formula, according to a coordinate corresponding to each test point in each row of test points, to obtain the transverse fitting curve of each row of test points; and

fitting the longitudinal electrode peak voltage ratio data corresponding to each test point in each column of test points by a set longitudinal fitting formula, according to a coordinate corresponding to each test point in each column of test points, to obtain the longitudinal fitting curve of each column of test points.

9. The positioning method of a single-surface position sensor according to claim 8, wherein the step of connecting points corresponding to transverse electrode peak voltage ratios of a position under test on various transverse fitting curves to obtain a curve L1, and connecting points corresponding to longitudinal electrode peak voltage ratios of the position under test on various longitudinal fitting curves to obtain a curve L₂ comprises:

pressing the position under test on the single-surface position sensor to be located, to obtain peak voltages of four electrodes corresponding to the position under test, and calculating a transverse electrode peak voltage ratio and a longitudinal electrode peak voltage ratio corresponding to the position under test;

determining one designated point on each transverse fitting curve, according to the transverse electrode peak voltage ratio corresponding to the position under test, and connecting or fitting designated points on all transverse fitting curves, to obtain a possible curve L₁ of the position under test; and

determining one designated point on each longitudinal fitting curve, according to the longitudinal electrode peak voltage ratio corresponding to the position under test, and connecting or fitting designated points on all longitudinal fitting curves, to obtain a possible curve L₂ of the position under test.