CAPACITIVE SENSOR AND METHOD FOR PLANAR RECOGNITION OF AN APPROACH

Abstract

A capacitive sensor for a planar recognition of an approach of an object. The capacitive sensor includes a first planar electrode and a second planar electrode, a dielectric being situated between the first electrode and second electrode for spacing. The first electrode and the second electrode being designed to be limp and/or torsion flexible.

Claims

1. A capacitive sensor for planar recognition of an approach of an object, the capacitive sensor comprising: a first planar electrode; a second planar electrode; a dielectric situated between the first electrode and second electrode for spacing; wherein the first electrode and the second electrode are limp and/or torsion flexible.

2. The capacitive sensor as recited in claim 1, wherein the first planar electrode and/or the second planar electrode each include a first partial electrode and a second partial electrode, the first and the second partial electrodes each being situated laterally spaced apart and forming electrical capacitances isolated from one another in such a way that a value of a capacitance of the capacitive sensor changes upon approach of an object.

3. The capacitive sensor as recited in claim 2, wherein the second electrode includes a third and a fourth partial electrode, the first, second, third, and fourth partial electrodes being interconnected in such a way that they form at least two electrical capacitances, the first, second, third, and fourth partial electrode being situated in such a way that detection areas of two electrical capacitances formed by electrical field lines at least partially overlap.

4. The capacitive sensor as recited in claim 1, wherein the first electrode and/or the second electrode each include a textile layer, wherein: (i) an electrode surface is situated on the textile layer, and/or (ii) the textile layer includes and/or forms an electrode surface.

5. The capacitive sensor as recited in claim 4, wherein the textile layer forms a microfiber nonwoven material.

6. The capacitive sensor as recited in claim 1, wherein electrode surfaces of the first electrode and/or the second electrode form: (i) a metal-coated textile, and/or (ii) a textile based on electrically conductive yarn.

7. The capacitive sensor as recited in claim 1, wherein the capacitive sensor includes a device side to be situated on a surface and a surroundings side for recognizing the object, the first electrode being situated on the device side with respect to the dielectric and the second electrode being situated on the surroundings side with respect to the dielectric, the first electrode forming a shielding electrode.

8. The capacitive sensor as recited in claim 1, wherein: (i) the dielectric is limp and/or torsion flexible, and/or (ii) the dielectric forms a spacer knit or a spacer fabric or spacer felt or spacer foam.

9. The capacitive sensor as recited in claim 1, further comprising: an electronics module including electronic components and an electronic carrier, the electronic components being situated on the electronic carrier, the electronic carrier forming a rigid circuit board or a flexible circuit board including vias for embroidery fastening and contacting with the aid of conductive yarn.

10. The capacitive sensor as recited in claim 1, wherein the first electrode and the second electrode are each connected to the dielectric with using a layer connection, the layer connection forming a permanent connection, and/or non-displaceable connection, and/or integrally-joined connection.

11. The capacitive sensor as recited in claim 10, wherein the layer connection is based on a lamination and/or an embroidery and/or adhesive bonding.

12. The capacitive sensor as recited in claim 9, further comprising: strip conductors, the strip conductors electronically connecting each of the electrodes to the electronics module and/or externally, the strip conductors being based on an electrical conductor, the electrical conductor being processable and/or embroiderable.

13. The capacitive sensor as recited in claim 12, wherein the electrical conductor forms a metal-coated yarn.

14. A method for recognizing an approach of an object, the method comprising: providing a capacitive sensor including a first planar electrode and a second planar electrode, the first planar electrode and the second planar electrode being situated spaced apart from one another using a dielectric, the first electrode and the second electrode being limp and/or torsion flexible; and recognizing the approach of the object using the capacitive sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 shows a schematic structure of a capacitive sensor, in accordance with an example embodiment of the present invention.

[0024] FIG. 2 shows a detail of a capacitive sensor including partial electrodes, in accordance with an example embodiment of the present invention.

[0025] FIGS. 3A and 3B show an electrical field between partial electrodes without and with object approach.

[0026] FIGS. 4A and 4B show a field line profile of a capacitive sensor with and without object approach according to FIGS. 3A and 3B.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0027] FIG. 1 shows an exemplary embodiment of a capacitive sensor 1. Capacitive sensor 1 is in particular designed to be planar and to be situated on a curved surface 2, for example, a device surface or a robot surface. Sensor 1 in particular includes a device side 3, device side 3 being formed to be situated and/or fastened on surface 2. Capacitive sensor 1 is in particular designed to be limp, torsion flexible, drapable, reversibly deformable, and/or flexible. In particular, the capacitive sensor includes a textile behavior and/or textile properties. Capacitive sensor 1 in particular forms a textile sensor. Capacitive sensor 1 includes a surroundings side 4, surroundings side 4 being oriented toward the surroundings. For example, the approach of a hand as object 5 to the sensor or surface 2 is establishable and/or detectable by capacitive sensor 1, in particular by measuring a changed capacity of capacitive sensor 1. Capacitive sensor 1 includes an electronics module 6, electronics module 6 including electronic components, for example, processors, memories, or functional modules, which are situated on a classic carrier (circuit board or flexible circuit board).

[0028] Capacitive sensor 1 includes a first electrode 7 and a second electrode 8, which are spaced apart via a dielectric 9. First electrode 7 in particular includes two partial electrodes 10c, second electrode 8 including four partial electrodes 10a, b. First electrode 7 is situated on the side of surface 2 with respect to dielectric 9, second electrode 8 being oriented toward surroundings 5 with respect to dielectric 9. First electrode 7 and second electrode 8 include textile properties and/or in particular form textile electrodes, these electrodes being fixedly connected to dielectric 9 with the aid of a layer connection. Furthermore, capacitive sensor 1 includes strip conductors 11, strip conductors 11 being embroidered from an electrically conductive yarn. Strip conductors 11 extend in particular through layers and/or plies of capacitive sensor 1, for example, second electrode 8 is connected to the electronics module through the other parts with the aid of strip conductors 11.

[0029] FIG. 2 shows by way of example a detail of a capacitive sensor 1. The capacitive sensor includes a first electrode 7 and a second electrode 8. First electrode 7 includes two partial electrodes 10c. Second electrode 8 includes four partial electrodes 10a and 10b. Partial electrodes 10a, b, c each form electrically conductive surfaces. Partial electrodes 10a form a rectangular frame, partial electrodes 10b being situated inside the frame. Partial electrodes 10a each include two legs, which are at right angles to one another. Partial electrodes 10b form rectangular surfaces, in particular square surfaces. Partial electrodes 10b are diagonally spaced apart inside the frame.

[0030] In each case one partial electrode 10a forms a capacitance with one, in particular the more remote, partial electrode 10b, so that two capacitances formed from four partial electrodes 10a, b result. After application of a voltage between partial electrodes 10a, b of the two capacitances, an electrical field including field lines 12 forms between them. It is preferably provided that the electrical field of the two capacitances is formed alternating over time. In one variant, it is provided that the electrical field of the two capacitances is formed at the same time. Upon approach of an object 5, the capacitance changes so that the approach of object 5 is detected. It is not necessary for object 5 to touch capacitive sensor 1, rather the change of the capacitance already occurs upon an approach of object 5. FIG. 3A shows the detail of capacitive sensor 1 from FIG. 2. In this case, field lines 12 of the electrical field of the capacitance formed by second electrode 2, in particular partial electrodes 10a, b, are shown by way of example. Field lines 12 extend in the surroundings, in particular surroundings air and/or the detection area.

[0031] FIG. 3B shows the detail of capacitive sensor 1 from FIG. 2 and FIG. 3A. In contrast to FIG. 3A, an object 5 is situated here in the surroundings or in the detection area. Object 5 changes the profile of field lines 12 of the electrical field of the capacitance of second electrode 8. This change of the electrical field is accompanied by a measurable change of the capacitance, so that object 5 may already be detected upon its approach due to the disturbance of the electrical field.

[0032] FIGS. 4A and 4B schematically show the profile of field lines 12 between object 5, first and second electrode 7, 8, and partial electrodes 10a, b, c. FIG. 4A shows the situation according to FIG. 3A without object 5 and FIG. 4B shows the situation according to FIG. 3B with object 5. Furthermore, an exemplary embodiment of a circuit structure for measuring the capacitance change is shown. A voltage source 13, in particular an AC voltage source, and a voltage meter 14 are provided for this purpose. For object 5, an equivalent circuit branch 15 is shown in FIG. 4B to illustrate the capacitance change due to object 5.