Apparatus and method used in disk drive for driving spindle motor

• US 6,841,954 B2
• Filed: 05/22/2003
• Issued: 01/11/2005
• Est. Priority Date: 07/31/2002
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nakabayashi, Yoichi
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US10/442,922
• Publication Number:
  US 20040212332A1
• Time in Patent Office: 600 Days
• Field of Search: 318 60- 65, 318/138, 318/254, 318/439, 318/601, 60/71, 60/730.3, 60/730.4, 60/75
• US Class Current: 318/62
• CPC Class Codes: G11B 19/2054 Spindle motor power-up sequences
• CPC Class Codes: G11B 19/28 Speed controlling, regulating, or indicating G11B19/24 takes precedence

Abstract

A CPU sets an SPM driver in SPM start-up mode when a SPM is started up. At this time, a voltage selector applies, to a driver circuit, a voltage (high voltage) boosted by a voltage booster. A starter control circuit controls, during the period of an SPM start-up mode, the driver circuit with the high voltage applied thereto, thereby starting up the SPM. After the SPM has been started up, the CPU sets the SPM driver in PWM mode. At this time, the voltage selector switches the voltage applied to the driver circuit, from the boosted voltage to the voltage (low voltage) of a power supply. During the period of the PWM mode, a PWM circuit controls the driver circuit with the low voltage applied thereto, so as to rotate the SPM at a rated speed.

Claims

1. A disk drive using a disk as a recording medium, comprising:

a spindle motor which rotates the disk;

a driver circuit which drives the spindle motor by supplying a current to the spindle motor;

a first control circuit which controls the spindle motor via the driver circuit to start up the spindle motor in a first mode;

a second control circuit which controls the spindle motor via the driver circuit to rotate the spindle motor at a rated speed in a second mode;

a voltage booster which boosts a power supply voltage from a disk drive power supply;

a voltage selector which selects, in the first mode as a voltage applied to the driver circuit, the power supply voltage boosted by the booster, and selects, in the second mode as the voltage applied to the driver circuit, the power supply voltage from the disk drive power supply; and

a controller which sets the first mode to start up the spindle motor, and sets the second mode when the spindle motor has been started up.

2. The disk drive according to claim 1, wherein the second control circuit controls, using pulse width modulation, the spindle motor to rotate it at the rated speed.

3. The disk drive according to claim 1, further comprising a main control circuit which controls the first control circuit, the second control circuit and the voltage selector, depending upon whether the controller has set the first mode or the second mode.

4. The disk drive according to claim 3, wherein:

if the controller sets the first mode, the main control circuit causes the voltage selector to select the power supply voltage boosted by the voltage booster, and operates the first control circuit; and

if the first mode is switched to the second mode, the main control circuit causes the voltage selector to select the power supply voltage from the disk drive power supply, stops an operation of the first control circuit and operate the second control circuit.

5. The disk drive according to claim 1, wherein the controller monitors a rotational speed of the spindle motor in the first mode, and determines that the spindle motor has been started up if the rotational speed of the spindle motor exceeds a predetermined value that is lower than the rated speed.

6. The disk drive according to claim 1, wherein the controller operates the voltage booster before the first mode is set, and stops an operation of the voltage booster after the first mode is switched to the second mode.

7. A spindle motor driver for use in a disk drive using a disk as a recording medium, the spindle motor driver driving a spindle motor which rotates the disk, comprising:

a driver circuit which drives the spindle motor by supplying a current to the spindle motor;

a first control circuit which controls the spindle motor via the driver circuit to start up the spindle motor;

a second control circuit which controls the spindle motor via the driver circuit to rotate the spindle motor at a rated speed;

a voltage booster which boosts a power supply voltage from a disk drive power supply;

a voltage selector which selects, as a voltage applied to the driver circuit, one of the power supply voltage from the disk drive power supply and the power supply voltage boosted by the booster; and

a main control circuit which controls the first control circuit, the second control circuit and the voltage selector, the main control circuit operating the first control circuit and causing the voltage selector to select the power supply voltage boosted by the voltage booster, if the spindle motor is in a first mode in which the spindle motor is started up, and the main control circuit stopping an operation of the first control circuit, operating the second control circuit and causing the voltage selector to select the power supply voltage from the disk drive power supply, if the spindle motor is in a second mode in which the spindle motor is rotated at a rated speed.

8. The spindle motor driver according to claim 7, wherein the second control circuit controls, using pulse width modulation, the spindle motor to rotate it at the rated speed.

9. A method, for use in a disk drive using a disk as a recording medium, of driving a spindle motor which rotates the disk, the method comprising:

setting a first mode when the spindle motor is started up;

switching the first mode to a second mode when the spindle motor has been started up;

controlling, in the first mode, a driver circuit which drives the spindle motor, to start up the spindle motor;

controlling, in the second mode, the driver circuit to rotate the spindle motor at a rated speed;

boosting, using a booster, a power supply voltage from a disk drive power supply;

applying, to the driver circuit in the first mode, the power supply voltage boosted by the booster; and

applying the power supply voltage from the disk drive power supply to the driver circuit in the second mode.

10. The method according to claim 9, further comprising:

monitoring a rotational speed of the spindle motor in the first mode; and

determining that the spindle motor has been started up if the rotational speed of the spindle motor exceeds a predetermined value lower than the rated speed.

11. The method according to claim 9, further comprising:

operating the voltage booster before the first mode is set; and

stopping an operation of the voltage booster after the first mode is switched to the second mode.