Western Digital Technologies, Inc.

Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Michiya Kazusawa

Masato Shiimoto

Satoshi Tabata

Atsushi Yamada

Naoto Ito

Erhard Theodor Schreck

Hiroaki Suzuki

Hideo Asano

Masayuki Kurita

Kenji Kuroki

Hideki Zaitsu

Hiroyasu Tanabe

Sarbanoo Das

Yoshihiko Maeda

Noriaki Sato

Jun Hashimoto

A magnetic recording system for preventing data loss resulting magnetic oscillator current. The magnetic recording system includes a magnetic write head with a magnetic write pole, a magnetic oscillator near the magnetic write pole, and a write coil for magnetizing the write pole. Circuitry is connected with the magnetic write coil to supply a current to the write coil and connected with the magnetic oscillator to supply a current to the magnetic oscillator. The circuitry is configured to ensure that the current to the magnetic oscillator does not inadvertently magnetize the write pole after the magnetic write pole has demagnetized.

Switching period control of microwave assisted magnetic recording for pole erasure suppression

A data storage device and method for improved flying height control (TFC) in a HAMR or MAMR system employing three heat sources to control the head protrusion: write coil current, TFC heater current, and media exciter power. The TFC heater is used to pre-heat the write head. The media exciter may be operated at a either a zero level or a low level below that required for the HAMR or MAMR process, optionally serving as an additional source of heat to the write head. The HAMR or MAMR data writing process commences only after the head protrusion has been increased and stabilized. During data writing, the media exciter power is increased to the higher level required to heat the disk medium in an HAMR or MAMR process and the TFC heater power is slightly reduced to maintain the total heat into the head approximately constant.

Write current and media heater control for heat or microwave assisted magnetic recording

A method of storing data includes providing a write signal for a write head of a hard disk drive, generating a transition pulse signal derived from the write signal using a transition pulse generator, and generating a logic signal to drive a thermal source associated with the write head of the hard disk drive. The logic signal includes the logical summation of a cyclical base pulse signal and the transition pulse signal.

Self-controlled laser pulsing for thermally assisted recording

A disk drive including a sensor element that senses contact between a head slider and a disk, a head integrated circuit (IC) comprising an amplification circuit section that amplifies a signal of the head slider, a controller IC comprising a controller that accesses a register of the head IC for controlling the head IC, and an identification section, within the head IC, that determines a contact frequency of the contact by the sensor element by using a timing control signal of the controller IC.

Head/disk contact determination

A data storage device, data write method, and program to avoid extra power consumption and suppress a write error that may result from voltage variations. To write data onto a magnetic disk, a write circuit generates a write current that is to be supplied to a write head. The write circuit operates on a positive power supply voltage provided by a host computer, and on a negative power supply voltage generated by a programmable DC&#x2014;DC converter mounted on a hard disk drive's card. The magnitude of the negative power supply voltage generated by the programmable DC&#x2014;DC converter is varied in accordance with the temperature surrounding the magnetic disk. Further, the magnitude of the negative power supply voltage generated by the programmable DC&#x2014;DC converter is varied in accordance with the magnitude of the positive power supply voltage supplied from the host computer.

Data storage device, data write method, and program

Growing community of inventors

Fujisawa, Japan

Michiya Kazusawa