Hard disk drive having dual micro-actuators on carriage arms

Patent metadata

Field	Value
Publication number	US-10984827-B2
Application number	US-202016797321-A
Country	US
Kind code	B2
Filing date	Feb 21, 2020
Priority date	Jul 10, 2019
Publication date	Apr 20, 2021
Grant date	Apr 20, 2021

Abstract

According to one embodiment, there is provided a hard disk drive including a first recording surface, a second recording surface, a first magnetic head, a first actuator and a second actuator that move the first magnetic head, a second magnetic head, a third actuator and a fourth actuator that move the second magnetic head, a fifth actuator that moves the second actuator and the fourth actuator, a drive circuit that implements at least one of a first mode in which the second actuator and the fourth actuator operate differently from each other or a second mode in which the first and third actuators operate differently from each other, and a controller that controls the drive circuit.

First claim

What is claimed is:

1. A hard disk drive comprising:
a first recording surface;
a second recording surface;
a first magnetic head that performs reading/writing on the first recording surface;
a first actuator that moves the first magnetic head;
a second actuator that moves the first magnetic head and the first actuator in an integrated manner;
a second magnetic head that performs reading/writing on the second recording surface;
a third actuator that moves the second magnetic head;
a fourth actuator that moves the second magnetic head and the third actuator in an integrated manner;
a fifth actuator that moves the second actuator and the fourth actuator in an integrated manner;
a drive circuit that implements at least one of a first mode in which the first actuator and the third actuator perform same operation and the second actuator and the fourth actuator perform different operations or a second mode in which the second actuator and the fourth actuator perform same operation and the first actuator and the third actuator perform different operations; and
a controller that controls the drive circuit.

2. The hard disk drive according to claim 1 , wherein the drive circuit includes a plurality of switches that switches a switching state to select, from the first actuator, the second actuator, the third actuator, and the fourth actuator, an actuator to which a drive signal is input.

3. The hard disk drive according to claim 1 , wherein the drive circuit is capable of selecting, with the controller, a third mode in which the first actuator and the second actuator operate in a mutually independent manner.

4. The hard disk drive according to claim 1 , wherein the first magnetic head and the second magnetic head are capable of reading/writing data different from each other on the first recording surface and the second recording surface simultaneously.

5. The hard disk drive according to claim 3 , wherein in the third mode, the third actuator performs operation same as operation performed by the first actuator, and the fourth actuator performs operation same as operation performed by the second actuator.

6. The hard disk drive according to claim 1 , wherein the drive circuit switches to the first mode or to the second mode.

7. The hard disk drive according to claim 1 , wherein the fifth actuator is driven by a voice coil motor (VCM).

8. The hard disk drive according to claim 3 , further comprising:
a third recording surface, wherein the drive circuit switches to the third mode in a case where, when the first magnetic head records servo information on the first recording surface, the controller determines that a distance between the third recording surface and the first recording surface is longer than a reference distance.

9. The hard disk drive according to claim 8 , wherein the drive circuit switches to the first mode or to the second mode in a case where, when the first magnetic head records servo information on the first recording surface, the controller determines that the distance between the third recording surface and the first recording surface is shorter than the reference distance.

10. The hard disk drive according to claim 9 , wherein the first magnetic head and the second magnetic head simultaneously record servo information on the first recording surface and the second recording surface.

11. The hard disk drive according to claim 1 , further comprising:
a fourth recording surface;
a third magnetic head that performs reading/writing on the fourth recording surface;
a sixth actuator that moves the third magnetic head; and
a seventh actuator that is provided between the fifth actuator and the third magnetic head and moves the third magnetic head and the sixth actuator in an integrated manner, wherein the sixth actuator and the first actuator perform same operation, and the seventh actuator and the second actuator perform same operation.

12. The hard disk drive according to claim 11 , wherein the same operation includes operation in which both two actuators are displaced by a same amount in a same direction, and the different operations include operation in which a displacement amount of one of two actuators is different from a displacement amount of the other actuator.

13. The hard disk drive according to claim 12 , wherein in the first mode and the second mode, the operation in which both two actuators are displaced by a same amount in a same direction includes operation in which the two actuators are not displaced by no signal being input to the two actuators or by a same signal being continuously input to the two actuators.

14. The hard disk drive according to claim 1 , wherein the first actuator, the second actuator, the third actuator, and the fourth actuator include a piezoelectric element.

15. The hard disk drive according to claim 2 , further comprising:
at least one signal generation circuit that outputs a plurality of digital signals different from each other for controlling any of the first actuator, the second actuator, the third actuator, and the fourth actuator, wherein the drive circuit includes a plurality of converters that converts a digital signal output from the signal generation circuit into an analog signal, and a plurality of amplifiers that amplifies the analog signal output from the converter and outputs the analog signal to the actuator as a drive signal.

16. The hard disk drive according to claim 15 , wherein at least one of the plurality of switches includes at least one end and another end, one end is electrically connected to the converter, and the other end is electrically connected to the amplifier, and the drive circuit switches a conduction state between one end and the other end of the switch under control of the controller.

17. The hard disk drive according to claim 16 , wherein the plurality of digital signals different from each other is output from a plurality of different output terminals of the signal generation circuit,
the plurality of output terminals is electrically connected to input of the different converters, and the first actuator, the second actuator, the third actuator, and the fourth actuator are electrically connected to output of the amplifier.

18. The hard disk drive according to claim 15 , wherein the switch has at least one end and another end, one end is electrically connected to the amplifier, and the other end is electrically connected to any of the first actuator, the second actuator, the third actuator, and the fourth actuator, and the drive circuit switches a conduction state of one end and the other end of the switch under control of the controller.

19. A hard disk drive comprising:
a plurality of recording surfaces including a first recording surface and a second recording surface;
a first magnetic head that performs reading/writing on the first recording surface;
a second magnetic head that performs reading/writing on the second recording surface;
a first actuator and a second actuator that move the first head;
a third actuator and a fourth actuator that move the second head;
a fifth actuator that moves the second actuator and the fourth actuator in an integrated manner;
a drive circuit that switches a combination of actuators to be operated independently among the first to fourth actuators; and
a controller that controls the drive circuit;
wherein the first actuator, the second actuator and the fifth actuator constitute a triple stage actuator (TSA), and the third actuator, the fourth actuator and the fifth actuator constitute a triple stag

Assignees

• Toshiba Kk
• Toshiba Electronic Devices & Storage Corp

Inventors

• Miyamoto Koichiro
• Oozeki Kenichiro
• Chen Yu

Classifications

• G11B5/4833 Primary

  Structure of the arm assembly, e.g. load beams, flexures, parts of the arm adapted for controlling vertical force on the head (G11B5/484 takes precedence) · CPC title

• G11B5/59633

  Servo formatting (G11B5/59627, G11B5/59677, G11B5/59683, G11B5/59688 take precedence) · CPC title

• G11B5/58

  with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following {(spacing means incorporated in the head structure G11B5/187, G11B5/255, G11B5/3106)} · CPC title

• G11B5/56

  with provision for moving the head {support} for the purpose of adjusting the position of the head relative to the record carrier, e.g. manual adjustment for azimuth correction or track centering ({G11B5/52,} G11B5/54, G11B5/58 take precedence) · CPC title

• G11B5/5573 Primary

  Details of the magnetic circuit, e.g. of actuators · CPC title