Magnetic encoder system

• US 7,141,965 B2
• Filed: 11/05/2004
• Issued: 11/28/2006
• Est. Priority Date: 11/26/2003
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kraemer, Hans-Guenter, Grimm, Hubert, Luckner, Nikolaus, Breuer, Marcus
• Primary Examiner(s): Patidar, Jay M.
• Application Number:
  US10/982,210
• Publication Number:
  US 20050116705A1
• Time in Patent Office: 753 Days
• Field of Search: 32420714-20717, 324/207.2, 324/207.21, 324/207.25, 324/207.26, 324/252, 338/32.R, 338/32.H
• US Class Current: 324/207.21
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06

Abstract

A magnetic encoder system according to one embodiment includes a magnetic sensor mounted on a first substrate above a magnetic medium, the magnetic medium carrying at least one magnetic track, the sensor detecting changes in the magnetic track during a relative movement between the sensor and the magnetic medium. The first substrate is provided with a second substrate rotatably engaging the magnetic medium.

Claims

1. A magnetic encoder system, comprising:

a magnetic sensor mounted on a first substrate above a magnetic medium, said magnetic medium carrying at least one magnetic track, said sensor detecting changes in said magnetic track during a relative movement between said sensor and said magnetic medium,

wherein said first substrate is provided with a second substrate rotatably engaging said magnetic medium,

wherein a pressure element is provided, said pressure element being adapted to press said first substrate smoothly in the direction of said magnetic medium.

2. The magnetic encoder system according to claim 1, wherein said pressure element is selected from a group consisting of a spring and a pneumatic/hydraulic pressure element.

3. A magnetic encoder system, comprising:

a magnetic sensor mounted on a first substrate above a magnetic medium, said magnetic medium carrying at least one magnetic track, said sensor detecting changes in said magnetic track during a relative movement between said set sensor and said magnetic medium,

wherein said first substrate is provided with a second substrate rotatably engaging said in magnetic medium,

wherein said magnetic medium includes a magnetic layer deposited on a third substrate.

4. The magnetic encoder system according to claim 3, wherein said third substrate is a rotatable disk.

5. The magnetic encoder system according to claim 3, wherein said third substrate is selected from the group consisting of plastic, ceramic, silicon and glass.

6. The magnetic encoder system according to claim 3, wherein said magnetic layer is covered by a protective layer.

7. The magnetic encoder system according to claim 6, wherein said protective layer is made of Al₂O₃.

8. The magnetic encoder system according to claim 6, wherein said protective layer is covered by a hard sandwich layer.

9. The magnetic encoder system according to claim 8, wherein said hard sandwich layer is made of SiC or SiN.

10. The magnetic encoder system according to claim 9, wherein a lubricant layer is positioned between said hard sandwich layer and said second substrate.

11. The magnetic encoder system according to claim 10, wherein the lubricant layer is selected from a group consisting of long chain hydrocarbons, MoS, MoSe, polytetrafluoroethylene (PTFE), perfluoropolyether (PFPE).

12. The magnetic encoder system according to claim 3, wherein GMR technology is used to form the magnetic sensor.

13. The magnetic encoder system according to claim 3, wherein TMR technology is used to form the magnetic sensor.

14. The magnetic encoder system according to claim 3, wherein said magnetic sensor is a read/write magnetic head.

15. A magnetic encoder system, comprising:

a magnetic sensor mounted on a first substrate above a magnetic medium, said magnetic medium carrying at least one magnetic track, said sensor detecting changes in said magnetic track during a relative movement between said sensor and said magnetic medium,

wherein said first substrate is provided with a second substrate rotatably engaging said magnetic medium,

wherein a distance between said magnetic sensor and said magnetic track is in a range of about 0.1 to 50 μ

m.

16. A magnetic encoder system, comprising:

a magnetic sensor mounted on a first substrate above a magnetic medium, said magnetic medium carrying at least one magnetic track, said sensor detecting changes in said magnetic track during a relative movement between said sensor and said magnetic medium,

wherein said first substrate is provided with a second substrate rotatably engaging said in magnetic medium,

wherein the system is encapsulated.

17. A magnetic encoder system, comprising:

a magnetic sensor mounted on a first substrate above a magnetic medium, said magnetic medium carrying at least one magnetic track, said sensor detecting changes in said magnetic track during a relative movement between said sensor and said magnetic medium,

wherein said first substrate is provided with a second substrate rotatably engaging said magnetic medium,

wherein the system is operatively coupled to a motor or spindle of a hard disk drive system.

18. A magnetic encoder system, comprising:

a magnetic sensor mounted on a first substrate above a magnetic medium;

a second substrate coupled to said first substrate, said second substrate operatively engaging a protective layer coupled to said magnetic medium;

said magnetic medium including a magnetic layer carrying at least one magnetic track, said sensor detecting changes in said magnetic track during a relative movement between said sensor and said magnetic medium.

19. The magnetic encoder system according to claim 18, wherein a pressure element is provided, said pressure element being adapted to press said first substrate smoothly in the direction of said magnetic medium.

20. The magnetic encoder system according to claim 19, wherein said pressure element is selected from a group consisting of a spring and a pneumatic/hydraulic pressure element.

21. The magnetic encoder system according to claim 18, wherein said magnetic medium includes a rotatable disk.

22. The magnetic encoder system according to claim 18, wherein said protective layer is covered by a hard sandwich layer.

23. The magnetic encoder system according to claim 18, wherein a lubricant layer is positioned between said magnetic medium and said second substrate.

24. The magnetic encoder system according to claim 18, wherein at least one of GMR and TMR technology is used to form the magnetic sensor.

25. The magnetic encoder system according to claim 18, wherein said magnetic sensor is a read/write magnetic head.

26. The magnetic encoder system according to claim 18, wherein a distance between said magnetic sensor and said magnetic track is in a range of about 0.1 to 50 μ

m.

27. The magnetic encoder system according to claim 18, wherein the system is encapsulated.

28. The magnetic encoder system according to claim 18, wherein the system is operatively coupled to a motor or spindle of a hard disk drive system.

29. A magnetic encoder system, comprising:

a magnetic sensor mounted on a first substrate above a magnetic medium, said magnetic sensor being a GMR or TMR sensor;

a second substrate coupled to said first substrate, said second substrate operatively and rotatably engaging said magnetic medium,

said magnetic medium including a magnetic layer carrying at least one magnetic track and a protect layer covering said magnetic layer,

said sensor detecting chances in said magnetic track during a relative movement between said sensor and said magnetic medium,

wherein a distance between said magnetic sensor and said magnetic track is in a range of about 0.1 to 50 μ

m.

wherein a lubricant layer is positioned between said second substrate and said magnetic medium.