Capacitive sensor device

• US 9,525,417 B2
• Filed: 11/27/2012
• Issued: 12/20/2016
• Est. Priority Date: 04/19/2011
• Status: Active Grant

• Current Assignee: Sumitomo Riko Company Limited.
• Original Assignee: Sumitomo Riko Company Limited.
• Inventors: Inada, Seishou, Guo, Shijie, Shiraoka, Takahisa, Isobe, Hiroshi
• Primary Examiner(s): Wagner, Jenny L
• Assistant Examiner(s): Ramaswamy, Arun
• Application Number:
  US13/686,325
• Publication Number:
  US 20130082763A1
• Time in Patent Office: 1,484 Days
• Field of Search: 361/283.1, 361/280, 361/291, 200/600, 345/173, 345/174, 327/517
• US Class Current: 1/1
• CPC Class Codes: G01L 1/146 for measuring force distributions, e.g. using force arrays G01L1/148 takes precedence
• CPC Class Codes: H03K 17/962 Capacitive touch switches

Abstract

Provided is a capacitive sensor device capable of detecting the position and magnitude of external force with high accuracy.

Employed is a capacitive sensor which comprises pairs of electrodes arranged in a matrix, each of the pairs of electrodes being disposed to face each other with a distance therebetween, and an elastically deformable dielectric layer arranged between each of the pairs of electrodes. A capacitance measuring part measures capacitance of respective electrode pair groups in a plurality of combinations each comprising more than one of the pairs of electrodes including a selected one of the pairs of electrodes. An external force calculating part calculates the magnitude of external force applied to the position of the selected pair of electrodes based on a plurality of measured values of the capacitance.

Claims

1. A capacitive sensor device, comprising:

a capacitive sensor comprising pairs of electrodes that are defined by respective first electrodes of a first electrode group and respective second electrodes of a second electrode group arranged in a matrix, each of the pairs of electrodes being disposed to face each other with a distance therebetween, and an elastically deformable dielectric layer arranged between each of the pairs of electrodes;

a capacitance measurer that measures capacitance of respective electrode pair groups in a plurality of combinations, each of the plurality of combinations of electrode pair groups comprising a same selected one of the pairs of electrodes and the pairs of electrodes adjoining the same selected one of the pairs of electrodes;

an external force calculator that calculates a magnitude of external force applied to position of the selected pair of electrodes based on a plurality of measured values of the capacitance;

an input switching circuit having a plurality of first switches; and

an output switching circuit having a plurality of second switches,

wherein the plurality of first switches are configured to connect at least two of the first electrodes to a voltage source and the plurality of second switches are configured to connect at least two of the second electrodes to the capacitance measurer such that a capacitance of at least a plurality of the pairs of electrodes can be directly measured at the same time.

2. The capacitive sensor device according to claim 1, wherein:

the first electrodes extend in a first direction and are arranged in a second direction perpendicular to the first direction;

the second electrodes extend in the second direction and are arranged in the first direction, and the second electrode group being arranged to face the first electrode group with a distance therebetween; and

the dielectric layer disposed between the first electrode group and the second electrode group.

3. The capacitive sensor device according to claim 1, wherein each of the electrode pair groups whose capacitance is to be measured by the capacitance measurer comprises a plurality of adjoining ones of the pairs of electrodes.

4. The capacitive sensor device according to claim 1, wherein each of the electrode pair groups whose capacitance is to be measured by the capacitance measurer is one of the electrode pair groups not including pairs of electrodes constituting a just measured one of the electrode pair groups.