DISK APPARATUS AND HEAD APPARATUS

• US 20190066729A1
• Filed: 03/01/2018
• Published: 02/28/2019
• Est. Priority Date: 08/30/2017
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Electronic Devices & Storage Corporation (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation), Toshiba Electronic Devices & Storage Corporation (Toshiba Corporation)
• Inventors: YAMASAKI, Nobuyoshi
• Granted Patent: US 10,242,708 B2
• Time in Patent Office: Days
• CPC Class Codes: G11B 20/18 Error detection or correction; Testing , e.g. of drop-outs
• CPC Class Codes: G11B 5/09 Digital recording
• CPC Class Codes: G11B 5/486 with provision for mounting or arranging electrical conducting means or circuits on or along the arm assembly
• CPC Class Codes: H05K 1/028 Bending or folding regions of flexible printed circuits H05K1/0283 takes precedence
• CPC Class Codes: H05K 1/111 Pads for surface mounting, e.g. lay-out
• CPC Class Codes: H05K 2201/09445 Pads for connections not located at the edge of the PCB, e.g. for flexible circuits
• CPC Class Codes: H05K 2201/10151 Sensor
• CPC Class Codes: H05K 2201/10159 Memory

Abstract

A disk apparatus includes a disk, a head, a circuit board, and an abnormality detection circuit. The head includes a plurality of loads, including at least a first load and a second load, associated with writing or reading of data to or from the disk, and a plurality of head terminals corresponding to and connected to the plurality of loads, respectively. The circuit board includes board terminals corresponding to and connected to the plurality of head terminals, respectively, and a preamplifier that applies a voltage to the loads via the plurality of board terminals during writing or reading of the data to or from the disk. The abnormality detection circuit detects a short-circuit between a first board terminal, which is the board terminal connected to the head terminal of the first load, and a second board terminal, which is the board terminal connected to the head terminal of the second load.

Claims

1. A disk apparatus comprising:

a disk;

a magnetic head including a plurality of loads, including at least a first load and a second load, and a plurality of head terminals corresponding to and connected to the plurality of loads, respectively;

a circuit board including a plurality of board terminals corresponding to and connected to the plurality of head terminals, respectively, and a preamplifier configured to apply a voltage to the loads via the plurality of board terminals, the plurality of board terminals including a first board terminal and a second board terminal that are connected to the first load via at least part of the head terminals, and a third board terminal that is connected to the second load via at least part of the head terminals and not connected to the first load;

a first abnormality detection circuit configured to detect a short-circuit between the first board terminal and the second board terminal; and

a second abnormality detection circuit configured to detect a short-circuit between the second board terminal and the third board terminal.

2. The disk apparatus according to claim 1, wherein the first board terminal and the second board terminal are adjacent to each other.

3. The disk apparatus according to claim 1, wherein

each of the loads is one of a write head configured to write the data to the disk, a read head configured to read the data from the disk, a first contact sensor configured to detect a contact between the write head and the disk, a second contact sensor configured to detect a contact between the read head and the disk, and a heater that is controlled to thermally expand the write head or the read head.

4. The disk apparatus according to claim 1, wherein the second abnormality detection circuit includes:

a power supply that applies a voltage between the second board terminal and the third board terminal; and

a comparator configured to compare an inter-terminal voltage between the second board terminal and the third board terminal with a reference voltage, and detect the short-circuit between the second board terminal and the third board terminal when the inter-terminal voltage exceeds the reference voltage.

6. The disk apparatus according to claim 1, further comprising:

a third abnormality detection circuit connected to one of the board terminals and configured to detect a ground fault thereof.

7. The disk apparatus according to claim 1, wherein the circuit board is a flexible circuit board.

5. (canceled)

8. A head apparatus comprising:

a magnetic head including a plurality of loads, including at least a first load and a second load, and a plurality of head terminals corresponding to and connected to the plurality of loads, respectively;

a circuit board including a plurality of board terminals corresponding to and connected to the plurality of head terminals, respectively, and a preamplifier configured to apply a voltage to the loads via the plurality of board terminals, the plurality of board terminals including a first board terminal and a second board terminal that are connected to the first load via at least part of the head terminals, and a third board terminal that is connected to the second load via at least part of the head terminals and not connected to the first load;

a first abnormality detection circuit configured to detect a short-circuit between the first board terminal and the second board terminal; and

a second abnormality detection circuit configured to detect a short-circuit between the second board terminal and the third board terminal.

9. The head apparatus according to claim 8, wherein the first board terminal and the second board terminal are adjacent to each other.

10. The head apparatus according to claim 8, wherein

each of the loads is one of a write head configured to write the data to a disk, a read head configured to read the data from the disk, a first contact sensor configured to detect a contact between the write head and the disk, a second contact sensor configured to detect a contact between the read head and the disk, and a heater that is controlled to thermally expand the write head or the read head.

11. The head apparatus according to claim 8, wherein the second abnormality detection circuit includes:

a power supply that applies a voltage between the second board terminal and the third board terminal; and

a comparator configured to compare an inter-terminal voltage between the second board terminal and the third board terminal with a reference voltage, and detect the short-circuit between the second board terminal and the third board terminal when the inter-terminal voltage exceeds the reference voltage.

13. The head apparatus according to claim 8, further comprising:

a third abnormality detection circuit connected to one of the board terminals and configured to detect a ground fault thereof.

14. The head apparatus according to claim 8, wherein the circuit board is a flexible circuit board.

12. (canceled)

15. A pre-amplifier circuit for a disk apparatus comprising:

a plurality of terminals including first, second, and third terminals in order with no other terminal between first and second terminals and no other terminal between the second and third terminals, the first and second terminals for connection to a first load on a magnetic head, and the third terminal for connection to a second load on the magnetic head and not to the first load;

a plurality of abnormality detection circuits; and

a plurality of inter-terminal abnormality detection circuits, wherein

one of the abnormality detection circuits is configured to detect a short-circuit between the first and second terminals, and

one of the inter-terminal abnormality detection circuits is configured to detect a short-circuit between the second and third terminals.

17. The circuit according to claim 15, wherein the terminals are connectable to terminals on a flexible circuit board, and the terminals on the flexible circuit board are connectable to terminals on the magnetic head.

18. The circuit according to claim 15, wherein one of the inter-terminal abnormality detection circuits includes:

a power supply that applies a voltage between the second and third terminals; and

a comparator configured to compare an inter-terminal voltage between the second and third terminals with a reference voltage, and detect the short-circuit between the second and third terminals when the inter-terminal voltage exceeds the reference voltage.

16. (canceled)