CAPACITANCE TYPE SENSOR

• US 20140326079A1
• Filed: 07/15/2014
• Published: 11/06/2014
• Est. Priority Date: 03/26/2012
• Status: Active Grant

• Current Assignee: Sumitomo Riko Company Limited.
• Original Assignee: Tokai Rubber Industries Limited
• Inventors: MAEDA, Ichinosuke, SHIBATA, Tetsuyoshi
• Granted Patent: US 9,274,010 B2
• Time in Patent Office: Days
• US Class Current: 73/862.626
• CPC Class Codes: G01L 1/142 using capacitors
• CPC Class Codes: G01L 1/144 with associated circuitry G01L1/146 and G01L1/148 take precedence
• CPC Class Codes: G01L 1/146 for measuring force distributions, e.g. using force arrays G01L1/148 takes precedence

Abstract

A capacitance type sensor includes: a dielectric layer made of a polymer; an elongated front-side electrode placed on a front side of the dielectric layer; an elongated back-side electrode placed on a back side of the dielectric layer; a front-side wiring connected to the front-side electrode; a back-side wiring connected to the back-side electrode; and a plurality of detection portions formed between the front-side electrode and the back-side electrode. Each of the front-side electrode and the back-side electrode has an elongated electrode body containing a binder and a conductive material, and an extended wiring portion extending in a longitudinal direction of the electrode body and having lower volume resistivity than the electrode body, and the front-side wiring and the back-side wiring have lower volume resistivity than the electrode body.

Claims

1. A capacitance type sensor, comprising:

a dielectric layer made of a polymer;

an elongated front-side electrode placed on a front side of the dielectric layer;

an elongated back-side electrode placed on a back side of the dielectric layer;

a front-side wiring connected to the front-side electrode;

a back-side wiring connected to the back-side electrode; and

a plurality of detection portions formed between the front-side electrode and the back-side electrode which face each other in a front-back direction,

the capacitance type sensor being capable of detecting surface pressure distribution based on a change in capacitance of the detection portion, characterized in that

each of the front-side electrode and the back-side electrode has an elongated electrode body containing a binder and a conductive material, and an extended wiring portion extending in a longitudinal direction of the electrode body and having lower volume resistivity than the electrode body, and

the front-side wiring and the back-side wiring have lower volume resistivity than the electrode body.

2. The capacitance type sensor according to claim 1, wherein

the extended wiring portion of the front-side electrode and the front-side wiring are made of the same material such that the extended wiring portion of the front-side electrode is continuous with the front-side wiring, and

the extended wiring portion of the back-side electrode and the back-side wiring are made of the same material such that the extended wiring portion of the back-side electrode is continuous with the back-side wiring.

3. The capacitance type sensor according to claim 1, wherein

the binder of the electrode body is a resin.

4. The capacitance type sensor according to claim 1, wherein

the volume resistivity of the electrode body is 1×

10¹ Ω

·

cm or less.

5. The capacitance type sensor according to claim 1, wherein

the extended wiring portion contains a binder and metal powder.

6. The capacitance type sensor according to claim 1, wherein

in each of the front-side electrode and the back-side electrode, electrical resistance between an upstream end to which the front-side wiring or the back-side wiring is connected and a downstream end as a longitudinal terminal end is 3,000Ω

or less.

7. The capacitance type sensor according to claim 1, wherein

the extended wiring portion has a smaller area than the electrode body.

8. The capacitance type sensor according to claim 1, wherein

the electrode body and the extended wiring portion are formed by a printing method.

9. The capacitance type sensor according to claim 1, further comprising:

a pair of front-side and back-side sheets that are placed with the dielectric layer interposed therebetween,

the front-side electrode is formed on a back surface of the front-side sheet which contacts the dielectric layer, and the extended wiring portion of the front-side electrode is interposed between the electrode body and the front-side sheet, and

the back-side electrode is formed on a front surface of the back-side sheet which contacts the dielectric layer, and the extended wiring portion of the back-side electrode is interposed between the electrode body and the back-side sheet.

10. The capacitance type sensor according to claim 1, wherein

the capacitance is measured by an electric charge method or an impedance method.