Hitachi, Ltd.

Hitachi Global Storage Technologies Netherlands B.v.

Hitachi Global Storage Technologies Japan, Ltd.

Hitachi Global Storage Netherlands, B.v.

Hitachi Video and Information Systems, Inc.

Shozo Saegusa

Mikio Tokuyama

Yuzo Yamaguchi

Masahiko Sega

Toshihisa Okazaki

Satomitsu Imai

Hayato Shimizu

Kenji Tomida

Hiroshi Nishida

Masaru Muranishi

Shinobu Yoshida

Hideaki Tanaka

Takeshi Yoshida

Shigeo Nakamura

Mike Suk

Masayuki Kurita

Remmelt Pit

Katsutoshi Nii

Shigenori Togashi

Toshiya Shiramatsu

Kazuo Sakai

Yuuichi Yanagase

Masao Iwakura

Toshiaki Kobari

Masayuki Kaiho

Donald Ray Gillis

Tsuyoshi Takahashi

Karl Arthur Flechsig

Kazuhiko Kawakami

Reinhard Ferdinand Wolter

Takashi Matsuki

Mitsuyuki Tsuyuki

Kouki Uefune

Katsuhiko Kimura

Hiroshi Ogasawara

Yoshiaki Yamauchi

Tetsuya Hamaguchi

Masayoshi Watanabe

Shinsuke Higuchi

Toshio Sugiyama

Tomokazu Ishii

Shigeki Mori

Hidekazu Kohira

Takako Hayakawa

Takeshi Harada

Masaaki Matsumoto

Hidehiko Kando

Kyo Akagi

Takashi Kouno

Takashi Yoshida

Takashi Yamaguchi

Toshihiro Arisaka

Kazutaka Sato

Hisahiro Miki

Atsushi Ichikawa

Akira Saito

Yasuhiro Matsuda

Katsuyuki Tanaka

Marutomo Goto

Akio Yabe

Kuniyuki Kimura

Akira Matsuda

Toshio Matsushita

Yoshihiro Sato

Mamoru Kainuma

Hiromitu Mori

A magnetic disc unit includes a rotating disc type magnetic disc, a head for recording and reproducing data to and from the magnetic disc, and a head support mechanism for supporting the head. The magnetic disc unit includes a shroud surrounding an outer periphery of the magnetic disc other than at least at an inserting part of a carriage arm which is linked to the magnetic head support mechanism. A gap between an end face of the outer periphery of the magnetic disc and the shroud is set in a range not less than 0.1 mm but not greater than 0.4 mm.

Magnetic disc unit with gap between magnetic disc and shroud

A magnetic disc unit includes a rotating disc type magnetic disc having an outer periphery, and a carriage arm linked to a head support mechanism for a recording/reproducing head. A base has an outer periphery and mounts the rotating disc type magnetic disc and the carriage arm, and has a side wall with an inner wall surface having an opening for inserting the carriage arm. The inner wall surface of the side wall defines a shroud surrounding the outer periphery of the magnetic disc, except at the opening in the side wall where the shroud is projected inwardly so as to decrease an opening angle of the opening in the side wall. A gap between the outer periphery of the magnetic disc and the shroud is set in a range not less than 0.1 mm but not greater than 0.6 mm.

A magnetic disk apparatus includes a plurality of magnetic disks driven to rotate by a spindle motor, arms supporting magnetic heads on the magnetic disks, an actuator for moving the arms on the magnetic disks by a voice coil motor, and a housing which surrounds the magnetic disks, the arms and the actuator. A shroud which arcuately surrounds the magnetic disks along the outer periphery thereof has an opened portion for inserting the arms is formed in a part of the housing. The shroud on an upstream side of the arms relative to airflow generated by the magnetic disks when rotating is provided with an opening having a greater width than that of a gap defined between the shroud and the outer periphery of the magnetic disks. An empty bypass channel is provided which communicates from the opening through a rear side of the voice coil motor to the downstream side of the arms.

Magnetic disk apparatus with shroud and having open space downstream of moveable arms in communication with bypass channel

A magnetic storage system according to one embodiment includes a magnetic disk having a load zone and a data area; at least one head for reading from and writing to the magnetic disk; and a slider for supporting the head. The load zone is created by: creating a load zone marker on the disk, the load zone marker indicating a position of a load zone of the disk; reading the load zone marker for determining a position of the load zone on the disk; and storing the position of the load zone. The head is loaded on the load zone during subsequent load operations. Methods are also presented.

Load/unload systems and methods for maximizing disk writeable area

Various embodiments of the present invention pertain to enabling location specific burnishing of a disk. According to one embodiment, the smoothness of a disk is evaluated by gliding over a disk to determine if there is an asperity on the disk. If there is an asperity on the disk, a location of the asperity is stored to enable location specific burnishing of the disk.

Enabling location specific burnishing of a disk

A system and method for loading a head onto a specified load zone of a disk includes reading positional index information for determining a position of a pre-specified load zone of a disk. When to load a head is determined based on the positional index information so that the head will load onto the load zone, the load zone having an arc of less than 360 degrees. The head is loaded from a ramp onto the load zone at the proper time.

Load/unload system and method for maximizing disk writeable area

A method for selectively sensing and removing asperities from the surface of hard disk drive media is disclosed. A thermally controlled flying height burnish slider is flown on a test stand with its thermal flying height control deactivated. The burnish slider flies at a nominal flying height over the surface of the media to remove any existing loose particles from the surface. A glide slider coupled to a PZT sensor is then flown over the surface of the media, the PZT sensor head mapping locations of any asperities on the surface of the media. The thermal flying height controlled burnish slider is next flown over the surface of the media with the thermal flying height control activated. The thermal flying height control is actuated when a mapped location of an asperity on the surface is proximate to the burnish slider, causing the burnish slider to protrude, wearing off the asperity.

Method for selectively sensing and removing asperities from hard disk drive media utilizing active thermally controlled flying heights

A system for selectively sensing and removing asperities from hard disk drive disk is disclosed. The system includes a test stand supporting the disk, the test stand having at least one suspension for flying over a surface of the disk. The system also includes a glide pad coupled to the at least one suspension for flying over the surface and locating asperities. A PZT sensor is coupled to the glide pad for sensing and mapping asperities on the surface of the disk. A burnish pad is coupled to the at least one suspension for wearing-away sensed and mapped asperities on the surface of the disk and a thermal fly height controller is coupled to the burnish pad for protruding the burnish pad when it is proximate to one of the mapped asperities for facilitating the wearing-away of the mapped asperity.

System and apparatus for selectively sensing and removing asperities from hard disk drive media utilizing active thermally controlled flying heights

A glide-height disk-tester operates with the test disk rotating at a predetermined constant rotational speed and uses a glide head with an electrically-resistive heater and a thermally-responsive protrusion pad located on its trailing end. The linear velocity of the disk relative to the slider maintains the slider at its nominal fly height, which is typically higher than any expected asperity. With no current applied to the heater, the protrusion pad is generally flush with the air-bearing surface of the slider. Increasing levels of current are applied to the heater, which causes movement of the protrusion pad toward the disk surface. When the pad contacts an asperity, the current level applied at the instant of asperity contact is recorded. The applied current level can be correlated to the glide height from a previous calibration process using a calibration disk with known calibration bump heights.

Glide-height disk-tester and method of operation

A magnetic disc unit having a rotating disc type magnetic disc, a head for recording and reproducing data to and from the magnetic disc, and a shroud surrounding an end surface of an outer periphery of the magnetic disc, except a part where a carriage arm is inserted, wherein a gap between the outer peripheral end surface of the magnetic disc and the shroud is set in a range which is greater than 0.1 mm but not greater than 0.6 mm.

Magnetic disc unit with range of gap between disc and shroud

A magnetic disk apparatus includes magnetic disks stacked on a rotating shaft, arms supporting magnetic heads, a rotary actuator for moving the arms, and a housing forming at least a part of an arcuate-shaped shroud which substantially surrounds a portion of side surfaces of the magnetic disks so as to define a gap between the shroud and the portion of the side surfaces of the magnetic disks. The arcuate-shaped shroud has portions delimiting an open space adjacent to another portion of the side surfaces of the magnetic disks which is located on a downstream side of the arms relative to an air flow which moves on surfaces of the magnetic disks. A bypass channel provides air flow to the disks in a region of the open space at a reduced pressure on the downstream side of the arms with respect to pressure at an upstream side of the arms.

Magnetic disk apparatus with air flow bypass channel

A spindle motor for magnetic disc device includes a hub having an inside and an outer peripheral side on which a magnetic disc is mounted, a rotary shaft having an axial direction and coupled with the hub so as to be integrally rotated therewith, with the motor being arranged on the inside of the hub. The hub, the rotary shaft and a part of the motor constitute a rotary body. A radial bearing having a length in the axial direction of the rotary shaft, for supporting the rotary body in a direction crossing the rotary shaft, and a thrust bearing for supporting the rotary body in the axial direction of the rotary shaft are provided. The thrust bearing has an outer diameter greater than the length of the radial bearing, and is arranged at a position which is inside of the motor and diametrically inward of the hub.

Spindle motor and magnetic disc device using thereof having radial and thrust bearings

A magnetic disc unit which can restrain occurrence of flutter so as to countermeasure such a problem that the larger the rotational speed of discs, the higher the flutter, causing heat positioning errors, in order that the high rotational speed and high positioning accuracy are consistent with each other. Discs are surrounded along their outer peripheries by a shroud (outer wall) while a gap between end faces of the discs and the shroud is decreased to a predetermined distance, thereby to eliminate air pressure differential between opposite surfaces of each of the discs in order to reduce flutter.

Magnetic disc unit

Shock-absorbing material made from a mixture of solid particles and viscous elastic material is arranged at the periphery of an information storage and retrieval device. When an external shock is applied to the device, the shock-absorbing material is greatly deformed and dissipates the shock energy by inner friction sufficiently to prevent damage to the inner mechanism of the device. The deformed shock-absorbing material can be restored to the original shape so that it is repeatedly usable. Furthermore, by comparing the deformed shape and the quick reference table provided with the device, the amount shock acceleration can be roughly determined. The device conforms to one of a series of dimensional standards for information storage and retrieval devices.

Information storage and retrieval device

Growing community of inventors

Ibaraki-ken, Japan

Shozo Saegusa