Head-gap calculating device, storage device, head-gap calculating method, and computer product
AssigneeFujitsu Limited
InventorAkihiro Yamazaki
Life of this patent
Estimating the term…
Abstract
A harmonic wave obtaining unit performs a fast Fourier transform (FFT) operation on repeatable run out (RRO) correction data in the time domain and transforms the RRO correction data into a higher harmonic signal data in the frequency domain. A selective-output unit outputs wavelength and amplitude of a first-order harmonic wave and of a third-order harmonic wave of the higher harmonic signal data to a hard disk controller via a formatting unit. A hard disk controller calculates a head-gap between a magnetic head and a magnetic disk in a storage device at the time of reading user data as well as servo data.
Claims12
A head-gap calculating device that calculates a head-gap between a storage medium and a head in a storage device, the head-gap calculating device comprising:
- a converting unit that receives via the head a plurality of analog signals from the storage medium, and converts the analog signals into digital signals;
- a wave-component obtaining unit that performs signal conversion on control signals necessary for reading user data from among the digital signals to obtain a fundamental wave component and a higher harmonic wave component;
- and
- a head-gap calculating unit that calculates the head-gap based on the fundamental wave component and the higher harmonic wave component.
A storage device comprising a head-gap calculating device that calculates a head-gap between a storage medium and a head in a storage device, the head-gap calculating device including
- a converting unit that receives via the head a plurality of analog signals from the storage medium, and converts the analog signals into digital signals;
- a wave-component obtaining unit that performs signal conversion on control signals necessary for reading user data from among the digital signals to obtain a fundamental wave component and a higher harmonic wave component;
- and
- a head-gap calculating unit that calculates the head-gap based on the fundamental wave component and the higher harmonic wave component.
A head-gap calculating method for calculating a head-gap between a storage medium and a head in a storage device, the head-gap calculating method comprising:
- converting a plurality of analog signals read via the head from the storage medium into digital signals;
- obtaining a fundamental wave component and a higher harmonic wave component by performing signal conversion on control signals necessary for reading user data from among the digital signals;
- and
- calculating the head-gap based on the fundamental wave component and the higher harmonic wave component.
A computer-readable recording medium that stores therein a computer program that causes a computer to calculate a head-gap between a storage medium and a head in a storage device, the computer program causing a computer to execute:
- converting a plurality of analog signals read via the head from the storage medium into digital signals;
- obtaining a fundamental wave component and a higher harmonic wave component by performing signal conversion on control signals necessary for reading user data from among the digital signals;
- and
- calculating the head-gap based on the fundamental wave component and the higher harmonic wave component.
Dependencies are inferred from the claim text.