Disk drives and host devices including a resetable shock sensor

• US 6,975,476 B1
• Filed: 02/28/2003
• Issued: 12/13/2005
• Est. Priority Date: 02/28/2003
• Status: Expired due to Fees

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Berding, Keith R.
• Primary Examiner(s): Hudspeth, David
• Assistant Examiner(s): OLSON, JASON C
• Application Number:
  US10/376,832
• Time in Patent Office: 1,019 Days
• Field of Search: 360/69, 360/75, 360/105, 360/106, 360/31, 360/78.01, 360/78.04, 73/13.8, 734/89, 734/94, 734/96
• US Class Current: 360/69
• CPC Class Codes: G11B 25/043 using rotating discs
• CPC Class Codes: G11B 31/006 with video camera or receiver
• CPC Class Codes: G11B 33/08 Insulation or absorption of undesired vibrations or sounds
• CPC Class Codes: G11B 5/5582 system adaptation for working during or after external perturbation, e.g. in the presence of a mechanical oscillation caused by a shock

Abstract

Disclosed herein are disk drives and mobile host devices that include a resetable shock sensor. A mobile host device may include a memory device configured to receive a shock event signal and a shock sensor. The shock sensor may be coupled to the memory device and is configured to generate the shock event signal. The shock sensor includes a fixed portion, and a movable portion responsive to shock events. The movable portion is configured to remain out of contact with the fixed portion until the mobile host device is subjected to a shock event greater than a predetermined magnitude and to contact and remain in contact with the fixed portion and to generate the shock event signal after the mobile host device is subjected to a shock event greater than the predetermined magnitude.

Claims

1. A mobile host device, comprising:

a memory device, the memory device being configured to receive a shock event signal;

a single tri-axial shock sensor coupled to the memory device and configured to generate the shock event signal, the single tri-axial shock sensor including;

a magnet defining a first region that is magnetized in a first polarization direction and defining a second region that is magnetized in a second polarization direction;

a fixed sensor assembly coupled to the first region of the magnet and magnetized in the first polarization direction;

a movable sensor assembly coupled to the second region of the magnet and magnetized in the second polarization direction, the movable sensor assembly being configured to;

remain out of contact with the fixed sensor assembly as long as the shock sensor does not undergo a shock event equal to or greater than a predetermined magnitude and to

deflect in any of the x, y and z directions to contact the fixed sensor assembly and change the level of the shock event signal irrespective of a direction of the shock event when the shock sensor undergoes a shock event in any direction whose magnitude is equal to or greater than the predetermined magnitude and to remain in contact with the fixed sensor assembly.

2. The mobile host device of claim 1, wherein the memory device is further configured to carry out a predetermined shock recovery operation depending upon a level of the received shock event signal.

3. The mobile host device of claim 1, further comprising a reset circuit coupled to the magnet and wherein the movable sensor assembly is further configured to remain in contact with the fixed sensor assembly until reset by the reset circuit.

4. The mobile host device of claim 3, wherein the reset circuit includes a selectively energizable electromagnet that is configured to generate a magnetic field counter to that of the magnet.

5. The mobile host device of claim 1, wherein the memory device includes spinning media.

6. The mobile host device of claim 5, wherein the memory device includes a magnetic disk drive.

7. The mobile host device of claim 1, further including a spring member coupled to the movable sensor assembly, the spring member being configured to keep the movable sensor assembly from contacting the fixed sensor assembly until the shock sensor undergoes the shock event that is equal to or greater than the predetermined magnitude.

8. The mobile host device of claim 1, wherein at least a portion of the shock sensor is fabricated using Micro-Electro-Mechanical-System (MEMS) processes.

26. The mobile host device of claim 1, wherein the fixed and movable sensors are configured such that the movable sensor is separated from the fixed movable sensor by first to sixth gaps corresponding to the +x, −

x, +y, −

y, +z and −

z directions respectively, and wherein the movable sensor is configured to deflect to close at least one of the first to sixth gaps and contact the fixed sensor when the shock sensor undergoes a shock event in any direction whose magnitude is equal to or greater than the predetermined magnitude.

9. A disk drive, comprising:

a disk;

a spindle motor for rotating the disk;

a head stack assembly for reading from and writing to the disk;

a controller for controlling the disk drive, and a single tri-axial resetable shock sensor coupled to the controller printed circuit board and configured to generate the shock event signal, the single tri-axial resetable shock sensor including;

a magnet defining a first region that is magnetized in a first polarization direction and defining a second region that is magnetized in a second polarization direction;

a reset circuit coupled to the magnet;

a fixed sensor assembly coupled to the first region of the magnet and magnetized in the first polarization direction;

a movable sensor assembly coupled to the second region of the magnet and magnetized in the second polarization direction, the movable sensor assembly being configured to;

remain out of contact with the fixed sensor assembly as long as the resetable shock sensor does not undergo a shock event equal to or greater than a predetermined magnitude and to

deflect in any of the x, y and z directions to contact the fixed sensor assembly and change the level of the shock event signal irrespective of a direction of the shock event when the resetable shock sensor undergoes a shock event in any direction whose magnitude is equal to or greater than the predetermined magnitude and to remain in contact with the fixed sensor until reset by the reset circuit.

10. The disk drive of claim 9, wherein the memory device is further configured to carry out a predetermined shock recovery operation depending upon a level of the received shock event signal.

11. The disk drive of claim 9, further comprising a reset circuit coupled to the magnet and wherein the movable sensor assembly is further configured to remain in contact with the fixed sensor assembly until reset by the reset circuit.

12. The disk drive of claim 11, wherein the reset circuit includes a selectively energizable electromagnet that is configured to generate a magnetic field counter to that of the magnet.

13. The disk drive of claim 9, wherein the memory device includes spinning media.

14. The disk drive of claim 13, wherein the memory device includes a magnetic disk drive.

15. The disk drive of claim 9, further including a spring member coupled to the movable sensor assembly, the spring member being configured to keep the movable sensor assembly from contacting the fixed sensor assembly until the shock sensor undergoes the shock event that is equal to or greater than the predetermined magnitude.

16. The disk drive of claim 9, wherein at least a portion of the shock sensor is fabricated using Micro-Electro-Mechanical-System (MEMS) processes.

27. The disk drive of claim 9, wherein the fixed and movable sensors are configured such that the movable sensor is separated from the fixed movable sensor by first to sixth gaps corresponding to the +x, −

x, +y, −

y, +z and −

z directions respectively, and wherein the movable sensor is configured to deflect to close at least one of the first to sixth gaps and contact the fixed sensor when the shock sensor undergoes a shock event in any direction whose magnitude is equal to or greater than the predetermined magnitude.

17. A mobile host device, comprising:

a memory device, the memory device being configured to receive a shock event signal;

a single tri-axial shock sensor coupled to the memory device and configured to generate the shock event signal, the single tri-axial shock sensor including;

a fixed portion;

a movable portion responsive to shock events, the movable portion being configured to remain out of contact with the fixed portion until the mobile host device is subjected to a shock event greater than a predetermined magnitude and to defect in any of the x, y and z directions to contact and remain in contact with the fixed portion and to generate the shock event signal irrespective of a direction of the shock event after the mobile host device is subjected to a shock event in any direction whose magnitude is greater than the predetermined magnitude.

18. The mobile host device of claim 17, wherein the memory device is further configured to carry out a predetermined shock recovery operation depending upon a level of the received shock event signal.

19. The mobile host device of claim 17, wherein the shock sensor further comprises a reset circuit and wherein the movable portion is further configured to remain in contact with the fixed portion until reset by the reset circuit.

20. The mobile host device of claim 17, wherein the shock sensor is configured such that a magnetic force maintains the movable portion in contact with the fixed portion after the mobile host device is subjected to a shock event greater than the predetermined magnitude.

21. The mobile host device of claim 17, wherein the shock sensor is configured such that a mechanical latch maintains the movable portion in contact with the fixed portion after the mobile host device is subjected to a shock event greater than the predetermined magnitude.

22. The mobile host device of claim 17, wherein shock sensor further includes a reset circuit to break the contact of movable portion with the fixed portion after the mobile host device is subjected to a shock event greater than the predetermined magnitude.

23. The mobile host device of claim 17, wherein the memory device includes spinning media.

24. The mobile host device of claim 17, wherein the memory device includes a magnetic disk drive.

25. The mobile host device of claim 17, wherein at least a portion of the shock sensor is fabricated using Micro-Electro-Mechanical-System (MEMS) processes.

28. The mobile host device of claim 17, wherein the fixed and movable portions are configured such that the movable portion is separated from the fixed movable portion by first to sixth gaps corresponding to the +x, −

x, +y, −

y, +z and −

z directions respectively, and wherein the movable portion is configured to deflect to close at least one of the first to sixth gaps and contact the fixed portion when the shock sensor undergoes a shock event in any direction whose magnitude is equal to or greater than the predetermined magnitude.