# US 6,721,124 B2 · Method and apparatus for providing an intelligent settle scheme for a hard disk drive with dual stage actuators

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- Number: US 6,721,124 B2
- Document ID: US6721124B2
- Status: Granted
- Kind: B2
- Application number: 09/753,967
- Filed: 2001-01-02
- Published: 2001-11-01
- Granted: 2004-04-13
- Earliest claimed: 2000-05-09
- Assignees: Maxtor Corporation
- Inventors: Jye-Kai Chang; Lin Guo
- Web page: https://patentgrep.com/patent/US6721124B2

## CPC

- G11B 5/5552: {using fine positioning means for track acquisition separate from the coarse (e.g. track changing) positioning means}
- G11B 5/5556: {with track following after a "seek"}
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

A method and apparatus for controlling the position of a computer hard disk drive transducer head are provided. According to the invention, an initial value compensation scheme is applied to a signal derived from available states of the transducer head when the control mode of the disk drive switches from a track seek mode to a settling mode. In particular, at least portions of a the compensation signal are provided to both a coarse actuator and a microactuator associated with the transducer head. According to one embodiment of the present invention, high frequency components of the compensation signal are generally provided to the microactuator, while low frequency components of the compensation signal are generally provided to the coarse actuator. The method and apparatus of the present invention provide a computer hard disk drive having improved performance due to reduced settling times and improved audible characteristics.

## Claims

### Claim 1

A method of controlling a disk drive transducer head following a seek operation, comprising:
producing an initial state signal;
introducing an initial value compensation scheme to said initial state signal to produce a compensation signal, wherein said compensation signal is produced no more than once per seek operation;
providing said compensation signal to first and second signal modifiers;
providing a first modified signal from said first signal modifier to a first actuator; and
providing a second modified signal from said second signal modifier to a second actuator, wherein said first and second actuators control a position of said transducer head with respect to tracks on a disk.

### Claim 2 (depends on 1)

The method of claim 1, wherein said first and second signal modifiers comprise first and second filters, and wherein said compensation signal is modified by said first filter to produce said first modified signal and wherein said compensated signal is modified by said second filter to produce said second modified signal.

### Claim 3 (depends on 1)

The method of claim 1, wherein said first signal modifier includes a first gain value.

### Claim 4 (depends on 1)

The method of claim 1, wherein said second signal modifier includes a second gain value.

### Claim 5 (depends on 2)

The method of claim 2, wherein said first filter comprises a high-pass filter.

### Claim 6 (depends on 2)

The method of claim 2, wherein said second filter comprises a low-pass filter.

### Claim 7 (depends on 1)

The method of claim 1, wherein said first actuator is a microactuator, and wherein said second actuator is a coarse actuator.

### Claim 8 (depends on 1)

The method of claim 1, wherein said second actuator comprises a voice coil motor.

### Claim 9 (depends on 7)

The method of claim 7, wherein said microactuator is selected from the group consisting of a piezoelectric actuator, an electromagnetic actuator, and an electrostatic actuator.

### Claim 10 (depends on 1)

The method of claim 1, wherein the compensation signal is produced once per transition from seek operation to track following operation.

### Claim 11 (depends on 1)

The method of claim 1, wherein the compensation signal is not produced during track following operations.

### Claim 12

A method for positioning a transducer head in a computer disk drive, comprising:
performing a seek operation;
producing a first information signal comprising information regarding a physical state of said transducer head;
introducing said first information to an initial value compensator to produce a compensation signal, wherein said compensation signal is produced no more than once per seek operation;
providing said compensation signal to a first signal modifier;
providing said compensation signal to a second signal modifier;
modifying said compensation signal using said first signal modifier to produce a first modified signal;
modifying said compensation signal using said second signal modifier to produce a second modified signal;
providing said first modified signal to a first actuator as a first control signal; and
providing said second modified signal to a second actuator as a second control signal.

### Claim 13 (depends on 12)

The method of claim 12, wherein said step of modifying said compensation signal using said first signal modifier to produce a first modified signal comprises passing said compensation signal through a first filter, and wherein said step of modifying said compensation signal using said second signal modifier to produce a second modified signal comprises passing said compensation signal through a second filter.

### Claim 14 (depends on 12)

The method of claim 12, wherein said step of modifying said compensation signal using said first signal modifier comprises multiplying said compensation signal by a first gain value.

### Claim 15 (depends on 12)

The method of claim 12, wherein said step of modifying said compensation signal using said second signal modifier comprises multiplying said compensation signal by a second gain value.

### Claim 16 (depends on 13)

The method of claim 13, wherein said first filter comprises a high pass filter.

### Claim 17 (depends on 13)

The method of claim 13, wherein said second filter comprises a low pass filter.

### Claim 18 (depends on 12)

The method of claim 12, wherein said first actuator is a microactuator, and wherein said second actuator is a coarse actuator.

### Claim 19 (depends on 18)

The method of claim 18, wherein said microactuator is selected from the group consisting of a piezoelectric actuator, and electromagnetic actuator, and an electrostatic actuator.

### Claim 20 (depends on 12)

The method of claim 12, wherein said second actuator comprises a voice coil motor.

### Claim 21 (depends on 12)

The method of claim 12, wherein the compensation signal is produced once per transition from seek operation to track following operation.

### Claim 22 (depends on 12)

The method of claim 12, wherein the compensation signal is not produced during track following operations.

### Claim 23

A disk drive having a dual-stage actuator, comprising:
a base;
a magnetic storage disk rotatably mounted to said base, wherein data is stored on said storage disk magnetically in concentric tracks, and wherein said tracks are divided into a plurality of data sectors;
an actuator arm comprising first and second members, wherein a first of said members is mounted to said base at a first end such that it is movable with respect to said magnetic storage disk, and wherein said second member is mounted to said first member such that it is movable with respect to said first member;
a transducer head coupled to said second member of said actuator arm, wherein said transducer head is capable of reading information from and writing information to said magnetic storage disk;
a coarse actuator for moving said first member of said actuator arm relative to said base;
a microactuator for moving said second member of said actuator arm relative to said first member of said actuator arm, wherein said transducer head is capable of addressing said concentric tracks by operation of at least one of said coarse actuator and said microactuator;
a controller for selectively actuating said coarse actuator and said microactuator to position said transducer head over a selected concentric track; and
a channel for processing and transmitting a signal from said transducer head to on board electronics and for transmitting a signal from said host computer to said transducer head, wherein following a seek operation a positional signal read by said transducer head and derived from a servo burst is modified by an initial value compensator to produce a compensation signal no more than once per seek operation, and wherein said compensation signal is provided to first and second signal modifiers, wherein a first modified signal produced by said first signal modifier is provided to said microactuator, and wherein a second modified signal produced by said second signal modifier is provided to said coarse actuator.

### Claim 24 (depends on 23)

The disk drive of claim 23, wherein said first signal modifier multiplies said compensation signal by a gain amount to produce said first modified signal.

### Claim 25 (depends on 23)

The disk drive of claim 23, wherein said second signal modifier multiplies said compensation signal by a second gain amount to produce said second modified signal.

### Claim 26 (depends on 23)

The disk drive of claim 23, wherein said first signal modifier comprises a filter.

### Claim 27 (depends on 23)

The disk drive of claim 23, wherein said second signal modifier comprises a filter.

### Claim 28 (depends on 23)

The disk drive of claim 23, wherein said first signal modifier comprises a high pass filter.

### Claim 29 (depends on 23)

The disk drive of claim 23, wherein said second signal modifier comprises a low pass filter.

### Claim 30 (depends on 23)

The disk drive of claim 23, wherein said microactuator is selected from the group consisting of a piezoelectric actuator, and electromagnetic actuator, and an electrostatic actuator.

### Claim 31 (depends on 23)

The disk drive of claim 23, wherein said coarse actuator comprises a voice coil motor.

### Claim 32 (depends on 23)

The disk drive of claim 23, wherein the compensation signal is produced once per transition from seek operation to track following operation.

### Claim 33 (depends on 23)

The disk drive of claim 23, wherein the compensation signal is not produced during track following operations.