Hgst Netherlands, B.v.

Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Akira Morinaga

Norifumi Miyamoto

Takayoshi Ohtsu

Shuichi Kojima

Koichi Nishioka

Satoshi Tabata

Masahiro Ito

Hideaki Tanaka

Nobumasa Nishiyama

Keiichi Nagasaka

Shigeru Tadokoro

Chiaki Ishikawa

Norihiro Ookawa

Wataru Kimura

Koji Okazaki

Masahiko Hatatani

Yasunobu Yanagisawa

A hard disk drive (HDD) is described which includes a magnetic field-generating device in the vicinity of a load/unload ramp such that the write head moves into a magnetic field generated by the device while the head is being unloaded from disk, whereby the magnetic field pins in a predominant direction the direction of magnetization of a magnetic shield associated with the write head, and away from the direction toward the disk. Recording magnetic field leakage associated with the shield is thereby suppressed and corresponding far track interference is inhibited.

Magnetization control for magnetic shield in magnetic recording head

A magnetic recording write head has a continuous electrically conductive plate with an aperture, a coil region around the aperture and heat-sink regions spaced from the coil region. A yoke stud is located in the aperture and connects the upper yoke layer to the main pole. The plate with the aperture replaces the multi-turn coil of the prior art and thus allows for a short yoke height. Write current is directed to the plate coil region and induces a magnetic field in the aperture, which generates magnetic flux in the yoke stud and the connected main pole. The heat-sink regions dissipate heat generated in the plate by the write current. A lower electrical lead layer is located below the plate and also has an aperture coincident with the aperture in the plate and a coil region around the aperture to assist in generating the magnetic field in the aperture.

Perpendicular magnetic recording write head with plate having coil regions and heat-sink regions

In one embodiment, a hard disk drive includes a magnetic disk medium, a magnetic head adapted for writing data to the magnetic disk medium, a mechanism (such as a detection circuit) adapted for detecting at least one recording condition of drive current provided to the magnetic head during writing operations, and an energy conversion element for controlling at least one recording characteristic of the magnetic head in response to the at least one detected recording condition. According to another embodiment, a method includes writing data to a magnetic medium using a magnetic head, detecting at least one recording condition of drive current provided to the magnetic head during the writing, and controlling at least one recording characteristic of the magnetic head during the writing using an energy conversion element in response to the at least one detected recording condition.

Hard disk drive with write assist based on detected conditions

In one embodiment, a magnetic head slider includes at least one magnetic head element chosen from a group consisting of: a write element adapted for writing data to a magnetic recording medium and a read element adapted for reading data from the magnetic recording medium, a heater element adapted for controlling a flying height of the at least one magnetic head element above the magnetic recording medium, a contact sensor element adapted for detecting contact between the magnetic head slider near the at least one magnetic head element and the magnetic recording medium, and shared terminals adapted for supplying voltage to the heater element and for conveying signals from the contact sensor element. Other magnetic head sliders and methods of use are described according to additional embodiments.

Magnetic head slider having shared heater and contact sensor terminal pads

A magneto-resistive effect head including: an antiferromagnetic layer; a pinned layer which is formed on the antiferromagnetic layer and whose magnetizing direction has been fixed; a spacer formed on the pinned layer; a free layer formed on the spacer; and magnetic domain control layers having antiferromagnetic flims and magnet layers for performing a magnetic domain control of the free layer; wherein the each of the antiferromagnetjc films is formed on the free layer; wherein the each of magnet layers has at least two magnetic films coupled anti-ferromagnetically through at least one nonmagnetic film; a pair of lead layers for supplying a current to the stack of layers; and wherein seed layers are formed between the antiferromagnetic films and the lead layers.

Magnetic head with magnetic domain control structure having anti-ferromagnetic layer and plural magnetic layers

In a narrow magnetoresistive head having a magnetic domain control film comprising a single layer of magnetic film or magnetic films antiferromagnetically coupled by means of a nonmagnetic member, it has been found that the magnetic domain can be controlled with a smaller magnetization film thickness product than anticipated so far and the range is defined relative to the geometrical track width in the present invention. By defining the magnetization film thickness product of the magnetic domain control film within a prescribed range of the invention, a magnetic head having higher output than usual and having stable output with no hysteresis in the transfer curve and with no output fluctuation can be attained.

Magnetoresistive head having defined relationships between the tract width and magnetization film thickness product to permit no hysteresis in the transfer curve

In a magnetoresistive head according to the present invention, a magnetic domain control film formed at the end of a free layer of a stack of magnetoresistive layers is formed of a Co alloy film, and an underlayer controlling the crystallization state of the Co alloy film and an amorphous metal film layer for controlling the crystallization state of the underlayer are disposed below the magnetic domain control film.

Magnetoresistive sensor with random crystal orientation underlayer and magnetic domain control film center aligned with free layer

The invention provides a magnetic domain controlling structure wherein a lamination stack Madjacent to a magnetoresistive stack of a GMR, CPP-GMR or TMR magnetic head has at least two magnetic filmsandanti-ferromagnetically coupled through a non-magnetic film, or the lamination stack Mdisposed on the end portions of the free layer of the magnetoresistive stack of the GMR magnetic head has a magnetic layer anti-ferromagnetically coupled to the free layerthrough the non-magnetic film. Ferromagnetic film deposition dead zone area problems and the consequent problem of film rippling in free layer portions that reduces element sensitivity are prevented, as is the problem of increased error from read drift in the magnetic field exchange coupling method, resulting in a highly stable, highly sensitive MR head with no loss of magnetic field intensity.

Magnetic head with a lamination stack to control the magnetic domain

A magneto-resistive effect head includes a magnetic domain control construction using both of an antiferromagnetic film and a magnetic domain control layer made of a magnet layer. The head is constructed by: an antiferromagnetic layer; a pinned layer which is formed on the antiferromagnetic layer and whose magnetizing direction has been fixed; a spacer formed on the pinned layer; a free layer formed on the spacer; magnetic domain control layers having antiferromagnetic films and magnet layers for performing a magnetic domain control of the free layer; and a pair of lead layers for supplying a current to a stack of the antiferromagnetic layer, pinned layer, spacer, and free layer. Thus, even for realization of a narrow track, a magneto-resistive effect head having large sensitivity and small side reading can be realized.

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Chigasaki, Japan

Akira Morinaga