Detector constructed from fabric having non-uniform conductivity

• US 6,369,804 B1
• Filed: 04/23/1999
• Issued: 04/09/2002
• Est. Priority Date: 09/26/1998
• Status: Expired due to Term

• Current Assignee: Wearable Technologies Ltd. (Blackline Safety Corp.)
• Original Assignee: Eleksen Limited (Peratech Limited)
• Inventors: Sandbach, David L.
• Primary Examiner(s): Liang, Regina
• Application Number:
  US09/298,172
• Time in Patent Office: 1,082 Days
• Field of Search: 345/173, 345/174, 178/18.01, 178/18.03, 178/18-5-, 338/99, 338/208
• US Class Current: 345/173
• CPC Class Codes: G01L 1/205 using distributed sensing elements
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact
• CPC Class Codes: H01H 2203/01 Woven wire screen
• CPC Class Codes: H01H 3/141 Cushion or mat switches

Abstract

A detector is constructed from fabric having electrically conductive elements to define at least two electrically conducting planes and configured to produce an electrical output in response to a mechanical interaction. A potential is applied across at least one of the planes to determine the position of a mechanical interaction and the second electrical property is determined to identify additional properties of the mechanical interactions. A conductivity non-uniformity is included in at least one of the planes so as to modify an electrical response to a mechanical interaction.

Claims

1. A detector constructed from fabric having electrically conductive elements to define a first electrically conductive plane and a second electrically conductive plane, wherein said planes are configured to produce an electrical output in response to a mechanical interaction, said detector comprising:

means for applying a first electrical potential across one of said planes to produce a first voltage gradient that can be used to determine the position of a mechanical interaction in a first direction by voltage measurement;

means for applying a second electrical potential across one of said planes to produce a second voltage gradient that can be used to determine the position of a mechanical interaction in a second direction by voltage measurement;

said first plane and said second plane having a substantially uniform conductivity except at one or more of their edges where conductivity is modified such that the conductivity of the plane overall is not uniform thus modifying said electrical output in response to said mechanical interaction by modifying the distribution of said voltage gradients; and

additional conducting thread is included to effect said modified conductivity.

2. A detector as in claim 1 wherein said first electrically conducting plane of non-uniform conductivity includes a co-operating pair of conducting strips configured to generate a first substantially linear electric field.

3. A detector as in claim 2 wherein said second electrically conducting plane includes a second co-operating pair of conducting strips configured to generate a second substantially linear electric field substantially orthogonal to said first co-operating pair of conducting strips.

4. A detector as in claim 1 wherein all edges of said first conducting plane are modified and all edges of the second conducting plane are modified.

5. A detector as in claim 1 wherein said electrically conductive elements are constructed from a fabric having electrically conducting fibers and electrically insulating fibers by a mechanical process, wherein electrical connection is made to electrically conducting fibers of said fabric during said mechanical process.

6. A detector as in claim 5 wherein said mechanical process comprises a knitting operation or weaving operation and said connection includes an insulation displacement connector.

7. A detector as in claim 1 having electrically conductive elements and configured to produce electrical outputs in response to mechanical interactions, wherein:

a detector surface is divided into a plurality of regions;

each of said regions includes a first conducting plane and a second conducting plane; and

said conducting planes of at least one of said regions being configured to cause mechanical interaction therewith to bring said planes closer together.

8. A detector as in claim 1 wherein:

at least one of said planes includes first portions and second portions,

said first portions having a higher resistance than said second portions, and

said first higher resistance portions being more flexible than said second portions.

9. A detector as in claim 1 configured to measure current in addition to measuring voltage so as to determine an applied pressure.

10. A detector as in claim 1 configured to measure current in addition to measuring voltage so as to determine an applied area of contact or orientation of an object.

11. A detector constructed from fabric having electrically conductive elements to define a first electrically conductive plane and a second electrically conductive plane, wherein said planes are configured to produce an electrical output in response to a mechanical interaction, said detector comprising:

means for applying a first electrical potential across one of said planes to produce a first voltage gradient that can be used to determine the position of a mechanical interaction in a first direction by voltage measurement;

means for applying a second electrical potential across one of said planes to produce a second voltage gradient that can be used to determine the position of a mechanical interaction in a second direction by voltage measurement;

said first plane and said second plane having substantially uniform conductivity except at one or more of their edges where conductivity is modified such that the conductivity of the plane overall is not uniform thus modifying said electrical output in response to said mechanical interaction by modifying the distribution of said voltage gradient; and

the density of said conducting elements being modified at said edge positions to effect said modified conductivity.

12. A detector as in claim 11, wherein:

said first electrically conducting plane of non-uniform conductivity includes a cooperating pair of conducting strips configured to generate a first substantially linear electric field.

13. A detector as in claim 12 wherein:

said second electrically conducting plane includes a second co-operating pair of conducting strips configured to generate a second substantially linear electric field substantially orthogonal to said first co-operating pair of conducting strips.

14. A detector as in claim 11 wherein:

all edges of said first conducting plane are modified and all edges of the second conducting plane are modified.

15. A detector as in claim 11 wherein:

said electrically conductive elements are constructed from a fabric having electrically conducting fibers and electrically insulating fibers by a mechanical process, and

electrical connection is made to electrically conducting fibers of said fabric during said mechanical process.

16. A detector as in claim 15 wherein said mechanical process comprises a knitting or weaving operation and said connection includes an insulation displacement connector.

17. A detector as in claim 11 having electrically conductive elements and configured to produce electrical outputs in response to mechanical interactions, wherein:

a detector surface is divided into a plurality of regions;

each of said regions includes a first conducting plane and a second conducting plane; and

said conducting planes of at least one of said regions being configured to cause mechanical interaction therewith to bring said plates closer together.

18. A detector as in claim 11 wherein:

at least one of said planes includes first portions and second portions, said first portions having a higher resistance than said second portions, and

said first higher resistance portions being more flexible than said second portions.

19. A detector as in claim 11 configured to measure current in addition to measuring voltage so as to determine an applied pressure.

20. A detector as in claim 11 configured to measure current in addition to measuring voltage so as to determine an applied area of contact or orientation of an object.

21. A method for detecting mechanical interaction with a detector constructed from fabric having electrically conductive elements to define a first electrically conductive plane and a second electrically conductive plane, wherein said planes are configured to produce an electrical output in response to a mechanical interaction, said method comprising:

applying a first electrical potential across one of said planes to produce a first voltage gradient used to determine the position of a mechanical interaction in a first direction by voltage measurement;

applying a second electrical potential across one of said planes to produce a second voltage gradient used to determine the position of a mechanical interaction in a second direction by voltage measurement;

said first plane and said second plane having a substantially uniform conductivity except at one or more of their edges where conductivity is modified such that the conductivity of the plane overall is not uniform thus modifying said electrical output in response to said mechanical interaction by modifying the distribution of said voltage gradients; and

effecting said modified conductivity by including additional conducting thread in said conductive planes.

22. A method as in claim 21 wherein said first electrically conducting plane of non-uniform conductivity uses a co-operating pair of conducting strips configured to generate a first substantially linear electric field.

23. A method as in claim 22 wherein said second electrically conducting plane use a second co-operating pair of conducting strips configured to generate a second substantially linear electric field substantially orthogonal to said first co-operating pair of conducting strips.

24. A method as in claim 21 wherein all edges of said first conducting plane are modified and all edges of the second conducting plane are modified.

25. A method as in claim 21 wherein said electrically conductive elements are constructed from a fabric having electrically conducting fibers and electrically insulating fibers by a mechanical process, wherein electrical connection is made to electrically conducting fibers of said fabric during said mechanical process.

26. A method as in claim 25 wherein said mechanical process comprises a knitting operation or weaving operation and said connection includes an insulation displacement connector.

27. A method as in claim 21 having electrically conductive elements and configured to produce electrical outputs in response to mechanical interactions, wherein:

a detector surface is divided into a plurality of regions;

each of said regions includes a first conducting plane and a second conducting plane; and

mechanically interacting with at least one of said regions causing conducting planes of said at least one of said regions to be brought closer together.

28. A method as in claim 21 wherein:

at least one of said planes includes first portions and second portions,

said first portions having a higher resistance than said second portions, and

said first higher resistance portions being more flexible than said second portions.

29. A method as in claim 21 including measurement of electrical current in addition to measuring electrical voltage and using the measured current to determine an applied pressure.

30. A method as in claim 21 including measurement of electrical current in addition to measuring electrical voltage and using the measured current to determine an applied area of contact or orientation of an object.

31. A method for detecting mechanical interaction with a detector constructed from fabric having electrically conductive elements to define a first electrically conductive plane and a second electrically conductive plane, wherein said planes are configured to produce an electrical output in response to a mechanical interaction, said method comprising:

applying a first electrical potential across one of said planes to produce a first voltage gradient used to determine the position of a mechanical interaction in a first direction by voltage measurement;

applying a second electrical potential across one of said planes to produce a second voltage gradient used to determine the position of a mechanical interaction in a second direction by voltage measurement;

said first plane and said second plane having substantially uniform conductivity except at one or more of their edges where conductivity is modified such that the conductivity of the plane overall is not uniform thus modifying said electrical output in response to said mechanical interaction by modifying the distribution of said voltage gradient; and

effecting said modified conductivity by modifying the density of said conducting elements at said edge positions.

32. A method as in claim 31 wherein:

said first electrically conducting plane of non-uniform conductivity includes a cooperating pair of conducting strips configured to generate a first substantially linear electric field.

33. A method as in claim 32 wherein:

said second electrically conducting plane includes a second co-operating pair of conducting strips configured to generate a second substantially linear electric field substantially orthogonal to said first co-operating pair of conducting strips.

34. A method as in claim 31 wherein:

all edges of said first conducting plane are modified and all edges of the second conducting plane are modified.

35. A method as in claim 31 wherein:

said electrically conductive elements are constructed from a fabric having electrically conducting fibers and electrically insulating fibers by a mechanical process, and

electrical connection is made to electrically conducting fibers of said fabric during said mechanical process.

36. A fabric method as in claim 35 wherein said mechanical process comprises a knitting or weaving operation and said connection includes an insulation displacement connector.

37. A method as in claim 31 having electrically conductive elements and configured to produce electrical outputs in response to mechanical interactions, wherein:

a detector surface is divided into a plurality of regions;

each of said regions includes a first conducting plane and a second conducting plane; and

mechanically interacting with at least one of said regions causing said conducting planes of said at least one of said regions to be brought closer together.

38. A method as in claim 31 wherein:

at least one of said planes includes first portions and second portions,

said first portions having a higher resistance than said second portions, and

said first higher resistance portions being more flexible than said second portions.

39. A method as in claim 31 including measurement of electrical current in addition to measuring electrical voltage and using the measured current to determine an applied pressure.

40. A method as in claim 31 including measurement of electrical current in addition to measuring electrical voltage and using the measured current to determine an applied area of contact or orientation of an object.