Capacitive proximity sensor for detecting component belts, component feeding device and method for detecting component belts

• US 20040175257A1
• Filed: 02/09/2004
• Published: 09/09/2004
• Est. Priority Date: 08/09/2001
• Status: Abandoned Application

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Pallas, Dirk
• Application Number:
  US10/486,097
• Publication Number:
  US 20040175257A1
• Time in Patent Office: Days
• US Class Current: 414/222.02
• CPC Class Codes: H03K 17/955 using a capacitive detector

Abstract

The invention relates to a capactive proximity sensor for detecting component belts, comprising at least two electrically conductive sensor surfaces (151, 152) which are arranged opposite each other on a non-conducting substrate having a low dielectricity number, whereby the component belts which are to be detected are detected in the millimetre range as a result of the low dielectric number of the substrate material and the geometric arrangement of the sensor surfaces (151, 152).

Claims

1. Capacitive proximity sensor for detecting component tapes, said sensor having

an electrically non-conducting substrate made of low dielectric constant material, and

at least two electrically conductive sensor surfaces (151, 152) implemented facing one another on the substrate,

so that because of the dielectric constant of the substrate material and the arrangement of the sensor surfaces (151, 152) on the substrate, component tapes (200) to be detected can be detected in the millimeter range.

2. Capacitive proximity sensor according to claim 1, wherein the dielectric constant of the substrate material is between 3 and 4 and the detection distance between 0.1 and 25 mm.

3. Capacitive proximity sensor according to claim 1 or 2, wherein the sensor surfaces (151, 152) are disposed in a single plane.

4. Capacitive proximity sensor according to one of claims 1 to 3, wherein the sensor surfaces (151, 152) are implemented in a meander or interdigitated pattern and the meanders or fingers of the sensor surfaces are intermeshed with a predetermined clearance with respect to one another.

5. Capacitive proximity sensor according to claim 4, wherein the predetermined clearance of the sensor surfaces with respect to one another is constant for the entire sensor.

6. Capacitive proximity sensor according to one of claims 1 to 5,

wherein a first sensor surface is an essentially rectangular basic surface having an extension disposed thereon in a first direction,

wherein the extension has a plurality of fingers in each case, and

wherein facing said extension there is disposed a second sensor surface which is provided with fingers so as to leave a meander-shaped interspace (300) between the first sensor surface and second sensor surface.

7. Capacitive proximity sensor according to claim 6, wherein the sensor (150) has a symmetrical structure with respect to the rectangular basic surface relative to the first direction, so that altogether the first sensor surface (151) has extensions respectively in and counter to the first direction, of which the extension disposed in the first direction faces the second sensor surface (152) and the extension disposed counter to the first direction faces the third sensor surface (153) which is implemented and disposed symmetrically with respect to the second sensor surface (152).

8. Capacitive proximity sensor according to one of claims 1 to 5, wherein a first sensor surface is an essentially rectangular basic surface having two extensions disposed thereon in a first direction, the extensions each having a plurality of fingers which are disposed facing the fingers of the other extension in each case, and a second sensor surface being disposed between the extensions which is provided with fingers facing the first sensor surface and the second sensor surface in such a way that a meander-shaped interspace (300) remains between the first sensor surface and the second sensor surface.

9. Capacitive proximity sensor according to claim 8, wherein the sensor (160) has a symmetrical structure with respect to the rectangular basic surface relative to the first direction, so that altogether there are formed the first sensor surface (161) with two extensions respectively in and counter to the first direction, the second sensor surface (162) between the two extensions disposed in the first direction and a third sensor surface (163), similar to the second sensor surface (162), disposed between the two extensions disposed counter to the first direction.

10. Capacitive proximity sensor according to claim 7, 9 or 10, wherein the first sensor surface is electrically connected to a reference potential.

11. Capacitive proximity sensor according to claim 7 or 9, wherein the sensor (150, 160) in the first direction is essentially made twice as long as an object to be detected.

12. Component feeding device with a component transporting device by means of which components can be transported in a feeding direction to an unloading position, and a sensor by means of which the presence or absence of objects can be detected, wherein

the sensor is a capacitive proximity sensor according to one of claims 1 to 11 which is disposed in proximity to the unloading position.

13. Component feeding device according to claim 12, wherein

the objects are components and/or coupling elements suitable and used for joining component tapes together.

14. Component feeding device according to claim 13, wherein the coupling elements are conductive and can be connected to a reference potential.

15. Component feeding device according to one of the preceding claims,

wherein the sensor is integral with a feeding channel through which the components can be transported to the unloading position.

16. Component feeding device according to one of the preceding claims, additionally having an evaluation device by which a sensor output signal can be processed.

17. Component feeding device according to claim 16, wherein the evaluation device is set up in such a way that digital filtering of the output signal is performed.

18. Method for detecting component tapes by means of a feeding device according to one of claims 12 to 17, wherein

an electric field is applied between the sensor surfaces of the capacitive proximity sensor,

the field applied is detected using the capacitive proximity sensor,

the field detected is analyzed by an evaluation device, and

from the analyzed field it is determined whether there is an object between the sensor surfaces.

19. Method according to claim 18, wherein

a component disposed in a component tape and/or a splicing strip for joining two component tapes is detected as the object to be detected.

20. Method according to claim 18 or 19, wherein by means of a capacitive proximity sensor according to claim 7, 9, 10 or 11

a first field detected between the first sensor surface and the second sensor surface and a second field detected between the second sensor surface and the third sensor surface are compared with one another in order to determine environmentally caused disturbances in the field applied between the sensor surfaces, and

the disturbances determined are taken into account in the analyzing of the detected field.