Head suspension with stacked coil microactuator for tracking axis adjustment of a read/write head

• US 5,867,347 A
• Filed: 06/13/1997
• Issued: 02/02/1999
• Est. Priority Date: 06/13/1997
• Status: Expired due to Term

• Current Assignee: Hutchinson Technology Incorporated (TDK Corporation)
• Original Assignee: Hutchinson Technology Incorporated (TDK Corporation)
• Inventors: Knight, Steven J., Girard, Mark T.
• Primary Examiner(s): HEINZ, ALLEN J
• Application Number:
  US08/874,137
• Time in Patent Office: 599 Days
• Field of Search: 360/106, 360/104
• US Class Current: 360/294.5
• CPC Class Codes: G11B 5/4873 the arm comprising piezoelectric or other actuators for adjustment of the arm
• CPC Class Codes: G11B 5/5552 using fine positioning means for track acquisition separate from the coarse (e.g. track changing) positioning means

Abstract

A disk drive suspension for mounting to the end of an actuator arm. The suspension includes a load beam having a rigid region, a proximal end, a flexure for receiving and supporting a read/write head on a distal end of the load beam, and a linkage for movably coupling the flexure to the proximal end of the load beam. A microactuator is located on the load beam and includes spaced first and second coil assemblies which undergo displacement perpendicular to the plane of the load beam in response to tracking control signals. The linkage translates the vertical displacement of the coil assemblies into displacement of the distal end of the load beam including the flexure along a transverse tracking axis.

Claims

1. A disk drive suspension configured for attachment to an actuator arm, including:

a load beam having a proximal end, a distal end, and a rigid region between the proximal end and the distal end;

a flexure at the distal end of the load beam, the flexure configured for receiving and supporting a read/write head;

a microactuator on the load beam and including first and second spaced actuator members responsive to tracking control signals wherein in response to tracking control signals at least the first actuator member generates a force on the second actuator member which causes a relative displacement between the first and second actuator members; and

a linkage coupled to the microactuator for translating the relative displacement between the first and second actuator members into a displacement of the distal end of the load beam including the flexure along a transverse tracking axis.

2. The disk drive suspension of claim 1 wherein:

the load beam includes a substantially planar rigid region; and

the relative displacement between the first and second actuator members is in a direction generally perpendicular to a plane defined by the substantially planar rigid region of the load beam.

3. The disk drive suspension of claim 2 wherein both the first and second actuator members include magnetic field generating coils.

4. The disk drive suspension of claim 3 wherein:

the rigid region of the load beam includes a proximal section and a distal section; and

the linkage includes;

at least one resilient member connecting the distal section to the proximal section such that the distal section can pivot about a connection point with respect to the proximal section; and

at least a first linkage member connecting the first actuator member to the proximal section and at least a second linkage member connecting the first actuator member to the distal section, such that in response to a displacement of the first actuator member, the first and second linkage members cause a distance in the plane of the load beam between the proximal section and the distal section to change, the change in distance causing the distal section to pivot with respect to the proximal section and move the flexure along the transverse tracking axis.

5. The disk drive suspension of claim 3 wherein:

the rigid region of the load beam includes a proximal section and a distal section; and

the linkage includes;

at least one longitudinally extending rail connecting the distal section to the proximal section; and

at least one linkage member coupling the first actuator member to the longitudinally extending rail, such that in response to tracking control signals a displacement of the first actuator member causes the linkage member to transversely displace the longitudinally extending rail moving the distal section of the load beam including the flexure along the transverse tracking axis.

6. The disk drive suspension of claim 3 wherein:

the rigid region of the load beam includes a proximal section and a distal section; and

the linkage includes;

a first linkage member coupled to the first actuator member and connecting the proximal section to the distal section such that a twisting deformation of the first linkage member changes a distance in the plane of the load beam between the proximal section and the distal section; and

a second linkage member connecting the proximal section to the distal section allowing the distal section to pivot with respect to the proximal section, such that in response to tracking control signals, a rotation of the first actuator member twistably deforms the first linkage member causing the distal section of the load beam to pivot with respect to the proximal section and move the flexure along the transverse tracking axis.

7. The disk drive suspension of claim 3 wherein:

the rigid region of the load beam includes a distal section, a proximal section, and an open region therebetween;

the first and second actuator members are located in the open region; and

the linkage includes;

first and second longitudinal edge rails, the second edge rail connecting the proximal section of the rigid region to the distal section;

a resilient transverse arm coupling the second edge rail to the first actuator member; and

a gap between the proximal section and the distal section and extending from the first edge rail to the open region;

such that in response to tracking control signals, a displacement of the first actuator member causes the transverse arm of the linkage to deform the second edge rail into the open region changing a longitudinal distance between the proximal section and the distal section causing the distal section of the rigid region to pivot with respect to the proximal section at an intersection of the gap and the first edge rail and moving the flexure along the transverse tracking axis with respect to the proximal section of the rigid region.

8. The disk drive suspension of claim 7 wherein the linkage includes:

first and second longitudinal arms coupling the second actuator member to the proximal section of the rigid region;

third and fourth longitudinal arms coupling the second actuator member to the distal section; and

such that in response to a displacement of the second actuator member, the first,

second, third, and fourth linkage arms change a longitudinal distance between the proximal section and the distal section, moving the distal section including the flexure along the transverse tracking axis.

9. The disk drive suspension of claim 8 wherein the second actuator member is attached to the proximal and distal section of the rigid region by resilient members.

10. The disk drive suspension of claim 8 wherein the second actuator member is resilient.

11. The disk drive suspension of claim 8 wherein the first and second actuator members displace away from each other.

12. The disk drive suspension of claim 3 wherein:

the rigid region of the load beam includes a distal section and a proximal section and an open region therebetween;

the first and second actuator members are located in the open region, and the linkage includes;

first and second longitudinal edge rails connecting the proximal section of the rigid region to the distal section;

a first linkage member extending from the distal section along the first longitudinal edge rail and connected to the first actuator member at a first location; and

a second linkage member extending from the proximal section along the second longitudinal edge rail and connected to the first actuator member at a second location transversely spaced from the first location;

such that in response to tracking control signals, a vertical displacement of the first actuator member changes a transverse distance between the first and second locations causing the distal section of the rigid region including the flexure to shift transversely, moving the flexure along the transverse tracking axis with respect to the proximal section of the rigid region.

13. The disk drive suspension of claim 12 wherein the first linkage member is attached to the second actuator member at a first location and the second linkage member is attached to the second actuator member at a second location transversely spaced from the first location such that a displacement of the second actuator member changes a transverse distance between the first and second locations causing the distal section of the rigid region including the flexure to shift transversely, moving the flexure along the transverse tracking axis with respect to the proximal section of the rigid region.

14. The disk drive suspension of claim 13 wherein both the first and second actuator members are attached to the first and second linkage members by resilient transverse fingers which have a reduced thickness with respect to a remainder of the load beam.

15. The disk drive suspension of claim 14 wherein the resilient transverse fingers are sloped with respect to a plane of the load beam such that the displacement of the first actuator member and the displacement of the second actuator member cause a greater transverse displacement of the distal end of the load beam including the flexure along the transverse tracking axis than would be caused if the fingers remained in the plane of the load beam.

16. The disk drive suspension of claim 3 wherein:

the rigid region of the load beam includes a distal section, a proximal section, and an open region therebetween;

the linkage includes first and second resilient longitudinal edge rails, the second edge rail connecting the proximal section of the rigid region to the distal section;

the first actuator member is located in the open region and includes an outer edge parallel and connected to the second edge rail along a length thereof, and

the second actuator member is located in the open region;

such that in response to tracking control signals, a rotation of the first actuator member out of a plane of the load beam twistedly deforms the second edge rail decreasing a longitudinal distance between the proximal section and the distal section and causing the distal section of the rigid region including the flexure to pivot about a point along the first longitudinal edge rail, moving the flexure along the transverse tracking axis with respect to the proximal section.

17. The disk drive suspension of claim 16 wherein the second actuator member is affixed to the proximal section of the rigid region and is further affixed to the distal section of the rigid region such that a displacement of the second actuator member decreases a longitudinal distance between proximal section and distal section pivoting the distal section about a point along the first edge rail and moving distal section including the flexure along the transverse tracking axis.

18. The disk drive suspension of claim 17 wherein the second actuator member is attached to the proximal and distal sections of the rigid region by resilient members.

19. The disk drive suspension of claim 17 wherein the second actuator member is resilient.

20. The disk drive suspension of claim 17 wherein the second actuator member is attached to the proximal section of the rigid region along a proximal edge of the second actuator member and is attached to the distal section of the rigid region along a distal edge of the second actuator member.

21. The disk drive suspension of claim 3 wherein:

the rigid region of the load beam includes a distal section, a proximal section, and an open region therebetween;

the first actuator member of the microactuator includes first and second lower magnetic field generating coil assemblies;

the second actuator member of the microactuator includes first and second upper magnetic field generating coil assemblies vertically spaced from the first and second lower coil assemblies; and

the linkage includes;

first and second lower longitudinal edge rails each having two ends and connecting the proximal section of the rigid region to the distal section;

a first lower torsion arm diagonally connecting the first lower edge rail to the proximal section; and

a first lower finger connecting the first lower coil assembly to the first lower torsion arm;

such that in response to tracking control signals, the first lower coil assembly rotates out of a plane of the load beam and the first lower finger of the linkage twists the first lower torsion arm shortening a longitudinal distance between the ends of the first lower edge rail such that the distal section of the rigid region including the flexure pivots about a point along the second lower edge rail with respect to the proximal section, moving the flexure along the transverse tracking axis.

22. The disk drive suspension of claim 21 wherein the linkage also includes:

a second lower torsion arm diagonally connecting the second lower edge rail to the proximal section; and

a second lower finger connecting the second lower coil assembly to the second lower torsion arm;

such that in response to tracking control signals, the second lower coil assembly rotates out of the plane of the load beam and the second lower finger of the linkage twists the second lower torsion arm shortening a longitudinal distance between the ends of the second lower edge rail such that the distal section of the rigid region including the flexure pivots about a point along the first lower edge rail with respect to the proximal section, moving the flexure along the transverse tracking axis.

23. The disk drive suspension of claim 21 wherein:

the linkage includes;

a support frame for supporting the first and second upper coil assemblies and having a proximal member attached to the proximal section of the rigid region and distal member attached to the distal section of the rigid region;

first and second upper longitudinal edge rails each having two ends and connecting the proximal member of the support frame to the distal member of the support frame;

a first upper torsion arm diagonally connecting the first upper edge rail to the proximal support member; and

a first upper finger connecting the first upper coil assembly to the first upper torsion arm;

such that in response to tracking control signals, the first upper coil assembly rotates out of a plane of the load beam and the first upper finger of the linkage twists the first upper torsion arm shortening the longitudinal distance between the ends of the first upper edge rail such that the distal section of the rigid region including the flexure pivots about a point along the second upper edge rail with respect to the proximal section, moving the flexure along the transverse tracking axis.

24. The disk drive of claim 23 wherein the linkage further includes:

a second upper torsion arm diagonally connecting the second edge rail to the proximal support member; and

a second upper finger connecting the second upper coil assembly to the second upper torsion arm;

such that in response to tracking control signals the second upper coil assembly rotates out of the plane of the load beam and the second upper finger of the linkage twists the second upper torsion arm shortening the longitudinal distance between the ends of the second upper edge rail such that the distal section of the rigid region including the flexure pivots about a point along the first upper edge rail with respect to the proximal section, moving the flexure along the transverse tracking axis.

25. The disk-drive suspension of claim 3 wherein:

the rigid region of the load beam includes a distal section, a proximal section, and an open region therebetween;

the first actuator member of the microactuator includes a lower proximal edge and a lower distal edge; and

the linkage includes;

a lower longitudinal edge rail connecting the distal section of the rigid region to the proximal section;

a resilient first lower partial thickness trough connecting the proximal edge of the first actuator member to the proximal section; and

a resilient second lower partial thickness trough connecting the distal edge of the first actuator member to the distal section; and

a transverse lower notch extending from the open region to the longitudinal edge rail;

such that in response to tracking control signals, a displacement of the first actuator member decreases a longitudinal distance between the distal and proximal sections of the rigid region pivoting the distal section with respect to the proximal section about the lower notch, moving the flexure along the transverse tracking axis with respect to the proximal section.

26. The disk drive suspension of claim 25 wherein:

the second actuator member of the microactuator includes an upper proximal edge and an upper distal edge; and

the linkage includes;

a support frame for supporting the second actuator member and having a proximal member attached to the proximal section of the rigid region, a distal member attached to the distal section of the rigid region, and an upper longitudinal edge rail;

an upper notch extending from the open region towards the upper transverse edge;

a first upper partial thickness trough connecting the upper proximal member of the support frame to the proximal edge of the second actuator member along an entire length thereof; and

a second upper partial thickness trough connecting the upper distal member of the support frame to the distal edge of the second actuator member along an entire length thereof;

such that a displacement of the second actuator member decreases a longitudinal distance between the distal and proximal sections of the rigid region pivoting the distal section with respect to the proximal section about the upper notch, moving the flexure along the transverse tracking axis with respect to the proximal section.

27. The disk drive suspension of claim 3 wherein the load beam is fabricated from a multi-layered sheet of material including a lower layer of stainless steel;

an intermediate dielectric layer; and

an upper conducting layer.

28. The disk drive suspension of claim 27 wherein the first and second actuator members are fabricated from the multi-layered sheet of material such that the magnetic field generating coil of the first actuator member includes a stainless steel base;

a conducting lead; and

a dielectric layer between the stainless steel base and the conducting lead.

29. The disk drive suspension of claim 27 wherein the second actuator member includes a magnetic field generating coil having a stainless steel base;

a conducting lead; and

a dielectric layer between the stainless steel base and the conducting lead.

30. A disk drive suspension configured for attachment to an actuator, including:

a load beam having a proximal end, a distal end, and a substantially planar rigid region between the proximal end and the distal end;

a flexure at the distal end of the load beam, the flexure configured for receiving and supporting a read/write head;

a microactuator on the load beam and including first and second spaced actuator members wherein in response to tracking control signals, at least the first actuator member generates a force on the second actuator member which causes a relative displacement between the first and second actuator members in a direction out of a plane defined by the substantially planar rigid region of the load beam; and

a linkage coupled to the microactuator for translating the relative displacement between the first and second actuator members into a displacement of the distal end of the load beam including the flexure along a transverse tracking axis.

31. The disk drive suspension of claim 30 wherein the relative displacement between the first and second actuator members is in a direction generally perpendicular to the plane defined by the substantially planar rigid region of the load beam.

32. The disk drive suspension of claim 31 wherein both the first and second actuator members include magnetic field generating coils.

33. The disk drive suspension of claim 32 wherein:

the rigid region of the load beam includes a proximal section and a distal section; and

the linkage includes;

at least one resilient member connecting the distal section to the proximal section such that the distal section can pivot about a connection point with respect to the proximal section; and

at least a first linkage member connecting the first actuator member to the proximal section and at least a second linkage member connecting the first actuator member to the distal section, such that in response to a displacement of the first actuator member, the first and second linkage members cause a distance in the plane of the load beam between the proximal section and the distal section to change, the change in distance causing the distal section to pivot with respect to the proximal section and move the flexure along the transverse tacking axis.

34. The disk drive suspension of claim 32 wherein:

the rigid region of the load beam includes a proximal section and a distal section; and

the linkage includes;

at least one longitudinally extending rail connecting the distal section to the proximal section; and

at least one linkage member coupling the first actuator member to the longitudinally extending rail, such that in response to tracking control signals a displacement of the first actuator member causes the linkage member to transversely displace the longitudinally extending rail moving the distal section of the load beam including the flexure along the transverse tracking axis.

35. The disk drive suspension of claim 32 wherein:

the rigid region of the load beam includes a proximal section and a distal section; and

the linkage includes;

a first linkage member coupled to the first actuator member and connecting the proximal section to the distal section such that a twisting deformation of the first linkage member changes a distance in the plane of the load beam between the proximal section and the distal section; and

a second linkage member connecting the proximal section to the distal section allowing the distal section to pivot with respect to the proximal section, such that in response to tracking control signals, a rotation of the first actuator member twistably deforms the first linkage member causing the distal section of the load beam to pivot with respect to the proximal section and move the flexure along the transverse tracking axis.