Fujitsu Corporation

Shin Tomimoto

Takao Sugawara

Hiroshi Ashikaga

The storage deviceprovides a signal detection method for preventing the degradation of an error rate at the time of information reading, caused by the change of a magnetic characteristic due to a non-uniform magnetic storage medium. The storage devicecomprises a storage mediumfor storing information, a reproduction signal generation unit for generating a reproduction signal, a synch mark pattern detection unitfor detecting a synch mark pattern from the reproduction signal, a filter setting unit for setting filters and filtersfor demodulating the reproduction signal and a data detection unitfor detecting data from the demodulated signal.

Method for detecting signal used when reading information from storage device

A magnetic disk control apparatus is capable of reducing the overall length of synchronization fields in split sectors and hence capable of increasing the storage capacity for data fields. The apparatus records data for each sector in such a manner that when a servo field is present in a sector, the sector is split into a first split sector and a second split sector each including a synchronization field and a data field. The apparatus has a storage medium, a head, a mechanical section that controls the relative position of the storage medium and the head, a hard disk controller that controls write timing and read timing, and a read channel that modulates and writes a synchronization field and a data field according to the write timing, performs phase synchronization and frequency synchronization based on the synchronization field read according to the read timing, and demodulates the data field according to the obtained phase and frequency. The synchronization field of each second split sector has a length required only for phase synchronization.

Magnetic disk control apparatus, magnetic disk control method, magnetic disk control program, and magnetic disk

A data storage apparatus for magnetic recording and regeneration on a medium. Only in case of a dibit or Tri-bit code sequence in MTR codes having a restricted number of magnetic transition consecutive, a write unit records the interval of the magnetic transition on the medium with an extension of &Dgr;T relative to the original magnetic transition interval. For the maximum likelihood detection after equalization of the medium read signals, a read unit adds to an expected value of the maximum likelihood detection an amplitude error &Dgr;V arising from the extension record of the magnetic transition interval relative to the original magnetic transition interval. A parameter regulation unit regulates and sets &Dgr;T and &Dgr;V by use of test patterns.

Growing community of inventors

Kawasaki, Japan

Shin Tomimoto