IP Library Granted Patent US 7,891,080
Granted Patent B2
US 7,891,080 · App. 11/935,711 · Granted Feb 22, 2011

Techniques for detecting head-disc contact

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Quick Facts
Patent No.
US 7,891,080
App. No.
11/935,711
Granted
Feb 22, 2011
Kind
B2
Abstract

A method for detecting head-disc contact is disclosed. The method comprises locating a head including a head positioning microactuator and at least one of a read transducer and a write transducer adjacent to a disc such that the head is in communication with the disc, monitoring an output signal from the head positioning microactuator of the head, and evaluating the output signal to determine if the head contacts the disc.

Claims (40)

1. A method for detecting head-disc contact comprising:

locating a head including a head positioning microactuator and at least one of a read transducer and a write transducer adjacent to a disc such that the head is in communication with the disc;

monitoring an output signal from the head positioning microactuator of the head;

evaluating the output signal by isolating a first sway mode of the microactuator to determine if the head contacts the disc; and

initiating an alarm in response to the head contacting the disc with a contact magnitude sufficient to result in physical damage to at least one of the head and the disc.

2. The method of claim 1 , further comprising performing a head merge operation to position the head on the disc while monitoring the output signal.

3. The method of claim 2 , wherein performing a head merge operation comprises using a static head merge tool to position the head on the disc.

4. The method of claim 1 , wherein evaluating the output signal comprises filtering the output signal with a band-pass filter.

5. The method of claim 1 , further comprising:

storing a record of the output signal if the head contacts the disc; and

inputting the record into a statistical process control system used to evaluate the output signal.

6. The method of claim 1 , wherein the head positioning microactuator is a piezoelectric microactuator.

7. The method of claim 1 , wherein a contact detection circuit monitors the output signal from the head positioning microactuator of the head, evaluates the output signal to determine if the head contacts the disc, and initiates the alarm in response to the head contacting the disc with the contact magnitude sufficient to result in physical damage to at least one of the head and the disc, wherein the contact detection circuit includes a comparator that evaluates the output signal to determine if the head contacts the disc.

8. A method for detecting head-disc contact comprising:

locating a head including a head positioning microactuator and at least one of a read transducer and a write transducer adjacent to a disc such that the head is in communication with the disc, wherein the head is a component of a bulk writing machine;

monitoring an output signal from the head positioning microactuator of the head;

evaluating the output signal by isolating a first sway mode of the microactuator to determine if the head contacts the disc; and

writing a servo pattern to the disc with the head.

9. The method of claim 8 , further comprising initiating an alarm in response to the head contacting the disc with a contact magnitude sufficient to result in physical damage to at least one of the head and the disc.

10. The method of claim 9 , wherein a contact detection circuit monitors the output signal from the head positioning microactuator of the head, evaluates the output signal to determine if the head contacts the disc, and initiates the alarm in response to the head contacting the disc with the contact magnitude sufficient to result in physical damage to at least one of the head and the disc, wherein the contact detection circuit includes a comparator that evaluates the output signal to determine if the head contacts the disc.

11. The method of claim 8 , further comprising installing the disc in a disc drive.

12. The method of claim 8 , wherein the head positioning microactuator is a piezoelectric microactuator.

13. A method for detecting head-disc contact comprising:

locating a head including a head positioning microactuator and at least one of a read transducer and a write transducer adjacent to a disc such that the head is in communication with the disc, wherein the head is a component of a media certification machine;

monitoring an output signal from the head positioning microactuator of the head;

evaluating the output signal by isolating a first sway mode of the microactuator to determine if the head contacts the disc;

performing reading and writing operations to the disc with the head; and

certifying a number of defects on the disc based on the reading and writing operations.

14. The method of claim 13 , further comprising initiating an alarm in response to the head contacting the disc with a contact magnitude sufficient to result in physical damage to at least one of the head and the disc.

15. The method of claim 14 , wherein a contact detection circuit monitors the output signal from the head positioning microactuator of the head, evaluates the output signal to determine if the head contacts the disc, and initiates the alarm in response to the head contacting the disc with the contact magnitude sufficient to result in physical damage to at least one of the head and the disc, wherein the contact detection circuit includes a comparator that evaluates the output signal to determine if the head contacts the disc.

16. The method of claim 13 , further comprising installing the disc in a disc drive.

17. A method for detecting head-disc contact comprising:

locating a head including a head positioning microactuator and at least one of a read transducer and a write transducer adjacent to a disc such that the head is in communication with the disc;

monitoring an output signal from the head positioning microactuator of the head;

evaluating the output signal by isolating a first sway mode of the microactuator to determine if the head contacts the disc; and

performing dynamic testing and certification of the head by reading and writing to the disc with the head.

18. The method of claim 17 , further comprising initiating an alarm in response to the head contacting the disc with a contact magnitude sufficient to result in physical damage to at least one of the head and the disc.

19. The method of claim 18 , wherein a contact detection circuit monitors the output signal from the head positioning microactuator of the head, evaluates the output signal to determine if the head contacts the disc, and initiates the alarm in response to the head contacting the disc with the contact magnitude sufficient to result in physical damage to at least one of the head and the disc, wherein the contact detection circuit includes a comparator that evaluates the output signal to determine if the head contacts the disc.

20. The method of claim 17 , further comprising installing the head in a disc drive.

21. The method of claim 17 , wherein the head positioning microactuator is a piezoelectric microactuator.

Assignments (7)
RELEASE OF SECURITY INTEREST Recorded Jul 23, 2025
From: THE BANK OF NOVA SCOTIA
To: SEAGATE TECHNOLOGY PUBLIC LIMITED COMPANY; SEAGATE TECHNOLOGY; SEAGATE TECHNOLOGY HDD HOLDINGS; I365 INC.; SEAGATE TECHNOLOGY LLC; SEAGATE TECHNOLOGY INTERNATIONAL; SEAGATE HDD CAYMAN; SEAGATE TECHNOLOGY (US) HOLDINGS, INC.
Reel/Frame 072193/0001 →
TERMINATION AND RELEASE OF SECURITY INTEREST IN PATENT RIGHTS Recorded Jul 19, 2013
From: WELLS FARGO BANK, NATIONAL ASSOCIATION, AS COLLATERAL AGENT AND SECOND PRIORITY REPRESENTATIVE
To: SEAGATE TECHNOLOGY LLC; EVAULT INC. (F/K/A I365 INC.); SEAGATE TECHNOLOGY INTERNATIONAL; SEAGATE TECHNOLOGY US HOLDINGS, INC.
Reel/Frame 030833/0001 →
SECURITY AGREEMENT Recorded Mar 24, 2011
From: SEAGATE TECHNOLOGY LLC
To: THE BANK OF NOVA SCOTIA, AS ADMINISTRATIVE AGENT
Reel/Frame 026010/0350 →
RELEASE Recorded Jan 19, 2011
From: JPMORGAN CHASE BANK, N.A., AS ADMINISTRATIVE AGENT
To: SEAGATE TECHNOLOGY HDD HOLDINGS; MAXTOR CORPORATION; SEAGATE TECHNOLOGY LLC; SEAGATE TECHNOLOGY INTERNATIONAL
Reel/Frame 025662/0001 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 30, 2009
From: MAXTOR CORPORATION
To: SEAGATE TECHNOLOGY LLC
Reel/Frame 022893/0855 →
SECURITY AGREEMENT Recorded May 15, 2009
From: MAXTOR CORPORATION; SEAGATE TECHNOLOGY LLC; SEAGATE TECHNOLOGY INTERNATIONAL
To: JPMORGAN CHASE BANK, N.A., AS ADMINISTRATIVE AGENT AND FIRST PRIORITY REPRESENTATIVE; WELLS FARGO BANK, NATIONAL ASSOCIATION, AS COLLATERAL AGENT AND SECOND PRIORITY REPRESENTATIVE
Reel/Frame 022757/0017 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 7, 2007
From: ALEXANDER, JAMES C.; LAKS, JASON H.
To: SEAGATE TECHNOLOGY LLC
Reel/Frame 020077/0169 →