Disk device

Patent metadata

Field	Value
Publication number	US-12211532-B2
Application number	US-202318454636-A
Country	US
Kind code	B2
Filing date	Aug 23, 2023
Priority date	Mar 23, 2023
Publication date	Jan 28, 2025
Grant date	Jan 28, 2025

Abstract

According to one embodiment, a disk device includes a disk-shaped recording medium, a magnetic head including a write head, a read head, and a heater, and a controller including a reference signal generator outputting a reference signal having a constant voltage amplitude at the same frequency as a high-frequency component of a gap measurement signal recorded in the recording medium, a measurer measuring a component amplitude of a reproduced signal of the gap measurement signal and an amplitude of the reference signal, and a heater controller controlling a power value of heater power supplied to the heater based on the measured values of the component amplitude and the amplitude of the reference signal.

First claim

What is claimed is:

1. A disk device comprising:
a disk-shaped recording medium on which a gap measurement signal containing a high-frequency component is recorded;
a magnetic head comprising a write head, a read head, and a heater to adjust a gap between the recording medium and the magnetic head; and
a controller including a reference signal generator outputting a reference signal having a constant voltage amplitude at the same frequency as the high-frequency component, a measurer measuring a component amplitude of a reproduced signal of the gap measurement signal and an amplitude of the reference signal, and a heater controller controlling a power value of heater power supplied to the heater based on the measured values of the component amplitude and the amplitude of the reference signal; wherein
the controller calculates an amount of change in the gap based on a ratio between an initial value of a component amplitude of the reproduced signal measured in a state where the magnetic head is in contact with the recording medium and a measured value of a component amplitude of the reproduced signal measured in the state where the gap is generated, and a ratio between an initial value of the amplitude of the reference signal and the measured value of the amplitude of the reference signal.

2. A disk device comprising:
a disk-shaped recording medium on which a gap measurement signal containing a high-frequency component is recorded;
a magnetic head comprising a write head, a read head, and a heater to adjust a gap between the recording medium and the magnetic head; and
a controller including a reference signal generator outputting a reference signal having a constant voltage amplitude at the same frequency as the high-frequency component, a measurer measuring a component amplitude of a reproduced signal of the gap measurement signal and an amplitude of the reference signal, and a heater controller controlling a power value of heater power supplied to the heater based on the measure values of the component amplitude and the amplitude of the reference signal; wherein
the gap measurement signal includes a signal pattern in which a third-order component amplitude of a reproduced signal is larger than a first-order component amplitude of a reproduced signal, and the controller controls the power value of the heater power based on the amount of change in the third-order component amplitude.

3. The disk device of claim 2 , wherein
in a case where a clock cycle of the gap measurement signal is T, the gap measurement signal includes a square wave pattern that reverses polarity every 2T, 1T, and 2T clock cycles.

4. The disk device of claim 1 , wherein
the controller comprises a head amplifier IC including a heater power supply circuit and an amplifier, and a main controller including the measurer and the heater controller, and
the reference signal generator is provided in the main controller.

5. The disk device of claim 1 , wherein
the controller comprises a head amplifier IC including a heater power supply circuit and an amplifier, and a main controller including the measurer and the heater controller, and
the reference signal generator is provided in the head amplifier IC.

6. The disk device of claim 2 , wherein
the controller comprises a head amplifier IC including a heater power supply circuit and an amplifier, and a main controller including the measure and the heater controller, and
the reference signal generator is provided in the main controller.

7. The disk device of claim 2 , wherein
the controller comprises a head amplifier IC including a heater power supply circuit and an amplifier, and a main controller including the measurer and the heater controller, and
the reference signal generator is provided in the head amplifier IC.

Assignees

• Toshiba Kk
• Toshiba Electronic Devices & Storage Corp

Inventors

• Watanabe Toru

Classifications

• G11B5/6029 Primary

  Measurement using values derived from the data signal read from the disk · CPC title

• G11B2005/0021

  Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal · CPC title

• G11B5/6064

  using air pressure · CPC title

• G11B5/607 Primary

  using thermal means · CPC title

• G11B17/00 Primary

  Guiding record carriers not specifically of filamentary or web form, or of supports therefor (guiding cards or sheets G06K13/00) · CPC title