Multicapacitor sensor array

• US 7,343,813 B1
• Filed: 02/15/2006
• Issued: 03/18/2008
• Est. Priority Date: 02/15/2005
• Status: Active Grant

• Current Assignee: College Park Industries, Inc. (Ossur hf)
• Original Assignee: Richard H. Harrington
• Inventors: Harrington, Richard H.
• Primary Examiner(s): Lefkowitz; Edward
• Assistant Examiner(s): DUNLAP, JONATHAN M
• Application Number:
  US11/355,052
• Time in Patent Office: 762 Days
• Field of Search: 737/80
• US Class Current: 73/780
• CPC Class Codes: G01L 1/146 for measuring force distributions, e.g. using force arrays G01L1/148 takes precedence
• CPC Class Codes: G01L 5/165 using variations in capacitance

Abstract

A new capacitive sensor array comprises a first plurality of conductors separated by a compressible insulator from a second plurality of conductors lying in a second plane parallel to the first plane. The second plurality of conductors are paired to partially overlap the first plurality of conductors, two by one in sets, whereby a shear force applied in a plane parallel to the conductor array will cause capacitance between the first and second conductors to change. Serially sampling the two by one sets for changes in capacitance provides information on both the magnitude and direction of shear. Moreover, forces applied perpendicular to the planes causes the insulator to compress, thus also changing the capacitances of the two by one sets of the sensor array. In the preferred embodiment, the imbalance of voltages between the paired conductors is applied to a differential amplifier to sense shear magnitude and direction. Compression force appears as an increase in peak voltage magnitude in both of the paired conductors.

Claims

1. A capacitive shear sensor array comprising:

a plurality of conductive drive plates lying in a first plane and

a plurality of conductive sense plates lying in a second plane parallel to the first plane,

said first and second planes separated by a dielectric;

each of the drive plates being partially overlapped by each of a pair of the sense plates, the pair of sense plates being spaced apart over the drive plate; and

means to energize a subset of drive plates and means to sample the capacitance of the sense plates overlapping the drive plates sequentially pair by pair,

wherein the means to sample the capacitance of the paired sense plates includes a differential amplifier.

2. A capacitive shear sensor array comprising:

a plurality of conductive drive plates having a plurality of crenelations lying in a first

a plurality of conductive sense plates having a plurality of crenelations lying in a second plane parallel to the first plane, said first and second planes separated by a dielectric;

each of the drive plates being partially overlapped by each of a pair of the sense plates, the pair of sense plates being spaced apart over the drive plate; and

means to energize a subset of drive plates and means to sample the capacitance of the sense plates overlapping the drive plates sequentially pair by pair,

wherein the means to sample the capacitance of the paired sense plates includes a differential amplifier.

3. The capacitive shear sensor array of claim 2 wherein the crenelations on the drive plate vary in width.

4. The capacitive shear sensor array of claim 2 wherein the crenelations on the sense plate vary in width.

5. A capacitive shear sensor array comprising:

a plurality of conductive drive plates having prongs and lying in a first plane and

a plurality of conductive sense plates having prongs and lying in a second plane parallel to the first plane, the drive plate prongs having crenelations and the sense plate prongs having crenelations, said first and second planes separated by a dielectric;

said crenelations varying in width;

each of the drive plates being partially overlapped by each of a pair of the sense plates, the pair of sense plates being spaced apart over the drive plate; and

means to energize a subset of drive plates, and means to sample the capacitance of the sense plates overlapping the drive plates sequentially pair by pair,

wherein the means to sample the capacitance of the paired sense splates includes a differential amplifier,

wherein when the sense plates halfway overlap the drive plates, maximum capacitance is achieved.