Two dimensional magnetoresistive position sensor

• US 6,326,782 B1
• Filed: 03/15/1999
• Issued: 12/04/2001
• Est. Priority Date: 03/15/1999
• Status: Expired due to Fees

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Schroeder, Thaddeus
• Primary Examiner(s): Snow, Walter E.
• Application Number:
  US09/270,904
• Time in Patent Office: 995 Days
• Field of Search: 324/207.21, 324/207.23, 324/252, 338/32.R, 345/160, 744/71.XY
• US Class Current: 324/207.21
• CPC Class Codes: G01B 7/004 for measuring coordinates of points

Abstract

A magnetosensitive die and actualizing circuit therefor by which a plurality of individual magnetosensitive elements are arranged and configured so as to produce a two dimensional position sensor which does not require the use of active components. Four MR elements are provided, wherein each MR element has an orthogonally serpentine configuration. A first MR sensor is formed of two MR elements that are diametrically opposed along a first axis, and a second MR sensor is formed of the remaining two MR elements which are diametrically opposed along a second, orthogonal axis. Each MR element is interdigitated with both of the MR elements of the other MR sensor, such that each MR sensor is electrically independent and orthogonally oriented with respect to the other MR sensor. Accordingly, one MR sensor consisting of two MR elements senses position along a first axis, and the other MR sensor consisting of the two other MR elements senses position along a second axis that is orthogonal to the first axis. The interdigitation of the MR elements may be accomplished with geometries other than orthogonally serpentine.

Claims

1. A die for a two dimensional position sensor, comprising:

a first magnetosensitive sensor comprising a first pair of diametrically disposed magnetosensitive elements; and

a second magnetosensitive sensor comprising a second pair of diametrically disposed magnetosensitive elements, wherein said first and second pairs of magnetosensitive elements are mutually orthogonally oriented and mutually interdigitated such that said first pair of magnetoresistive elements is electrically independent of said second pair of magnetosensitive elements, and wherein said first and second magnetosensitive elements are substantially equally magnetically biased;

wherein said first magnetosensitive sensor senses movement of a magnetic material target along a first axis, and wherein said second magnetosensitive sensor senses movement of a magnetic material target along a second axis that is orthogonal to the first axis.

2. The die of claim 1, wherein each magnetosensitive element comprises a multiplicity of magnetosensitive cells.

3. The die of claim 1, wherein said first and second pairs of magnetosensitive elements comprise:

a first magnetosensitive element;

a second magnetosensitive element, wherein said first and second magnetosensitive elements are diametrically disposed in relation to a first axis;

a third magnetosensitive element; and

a fourth magnetosensitive element, wherein said third and fourth magnetosensitive elements are diametrically disposed in relation to a second axis;

wherein said first and second axes are orthogonal to each other; and

wherein said first and second magnetosensitive elements are independently interdigitated with said third and fourth magnetosensitive elements, and said third and fourth magnetosensitive elements are independently interdigitated with said first and second magnetosensitive elements.

4. The die of claim 3, wherein said interdigitation is orthogonally serpentine.

5. The die of claim 4, wherein each magnetosensitive element comprises a plurality of parallel segments serially connected by conductive bridges;

and wherein said interdigitation is compact.

6. The die of claim 3, wherein each magnetosensitive element comprises a multiplicity of magnetosensitive cells.

7. The die of claim 6, wherein each magnetosensitive element comprises a plurality of parallel segments serially connected by conductive bridges, wherein the magnetosensitive cells of each segment are demarcated by a multiplicity of regularly spaced shorting bars located thereupon.

8. The die of claim 7, wherein said interdigitation is orthogonally serpentine.

9. The die of claim 8, wherein said interdigitation is compact.

10. A two dimensional position sensor, comprising:

a first magnetosensitive sensor comprising a first pair of diametrically disposed magnetosensitive elements, wherein said first magnetosensitive sensor senses movement of a magnetic material target along a first axis;

a second magnetosensitive sensor comprising a second pair of diametrically disposed magnetosensitive elements, wherein said first and second pairs of magnetosensitive elements are mutually orthogonally oriented and mutually interdigitated such that said first and second magnetosensitive elements are substantially equally magnetically biased, wherein said second magnetosensitive sensor senses movement of the magnetic material target along a second axis that is orthogonal to the first axis; and

circuit means comprising passive components connected with said first and second magnetosensitive sensors for providing a signal responsive to said first and second magnetosensitive sensors to sensing position of the magnetic material target with respect thereto, wherein said first pair of magnetoresistive elements is electrically independent of said second pair of magnetosensitive elements.

11. The position sensor of claim 10, wherein each magnetosensitive element comprises a multiplicity of magnetosensitive cells.

12. The position sensor of claim 10, wherein said first and second pairs of magnetosensitive elements comprise:

a first magnetosensitive element;

a second magnetosensitive element, wherein said first and second magnetosensitive elements are diametrically disposed in relation to a first axis;

a third magnetosensitive element; and

a fourth magnetosensitive element, wherein said third and fourth magnetosensitive elements are diametrically disposed in relation to a second axis;

wherein said first and second axes are orthogonal to each other; and

wherein said first and second magnetosensitive elements are independently interdigitated with said third and fourth magnetosensitive elements, and said third and fourth magnetosensitive elements are independently interdigitated with said first and second magnetosensitive elements.

13. The position sensor of claim 12, wherein said interdigitation is orthogonally serpentine.

14. The position sensor of claim 13, wherein each magnetosensitive element comprises a plurality of parallel segments serially connected by conductive bridges;

and wherein said interdigitation is compact.

15. The position sensor of claim 12, wherein each magnetosensitive element comprises a multiplicity of magnetosensitive cells.

16. The position sensor of claim 15, wherein each magnetosensitive element comprises a plurality of parallel segments serially connected by conductive bridges, wherein the magnetosensitive cells of each segment are demarcated by a multiplicity of regularly spaced shorting bars located thereupon.

17. The position sensor of claim 16, wherein said interdigitation is orthogonally serpentine.

18. The position sensor of claim 17, wherein said interdigitation is compact.

19. A die for a two dimensional position sensor, comprising:

a first magnetosensitive sensor comprising a first pair of diametrically disposed magnetosensitive elements; and

a second magnetosensitive sensor comprising a second pair of diametrically disposed magnetosensitive elements, wherein said first and second pairs of magnetosensitive elements are mutually orthogonally oriented and mutually interdigitated such that said first pair of magnetoresistive elements is electrically independent of said second pair of magnetosensitive elements, and wherein said first and second magnetosensitive elements are equally magnetically biased;

wherein said first magnetosensitive sensor senses movement of a magnetic material target along a first axis, and wherein said second magnetosensitive sensor senses movement of a magnetic material target along a second axis that is orthogonal to the first axis; and

wherein each magnetosensitive element comprises a multiplicity of magnetosensitive cells.

20. The die of claim 19, wherein each magnetosensitive element comprises a plurality of parallel segments serially connected by conductive bridges, wherein the magnetosensitive cells of each segment are demarcated by a multiplicity of regularly spaced shorting bars located thereupon.