Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Kabushiki Kaisha Toshiba

Hitachi Global Storage Technologies Netherlands B.v.

Toshiba Electronic Devices & Storage Corporation

Hiroshi Tani

Hiroyuki Matsumoto

Takayuki Nakakawaji

Mitsuhiro Shoda

Yutaka Ito

Mina Ishida

Yoshiki Kato

Takao Nakamura

Heigo Ishihara

Nobuya Sekiyama

Yoko Ogawa

Hiroyuki Suzuki

Mikio Tokuyama

Koji Sonoda

Junguo Xu

Toshinori Ono

Ryuji Tsuchiyama

Tomonori Kozaki

Kazuhiko Takaishi

Yuzuru Hosoe

Akira Kato

Yoshibumi Matsuda

Hidekazu Kohira

Masayuki Kurita

Masaaki Matsumoto

Yotsuo Yahisa

Hiromitsu Tokisue

Yoshinori Honda

Masaki Ohura

Koji Sakamoto

Katsuo Abe

Takaaki Shirakura

Yuuichi Kokaku

Katsuyuki Tanaka

Shigehiko Fujimaki

Muneo Mizumoto

Mina Amo

Kouji Sonoda

Shinichi Hirose

Yoshihiro Sato

Susumu Funamoto

Youichi Inoue

Sunao Yonekawa

Toru Yatsue

Masanori Inoue

Mitsuhiro Shyoda

Hiroshi Ishikawa

According to one embodiment, a magnetic disk device writes a plurality of simulated reference patterns to the magnetic disk on write conditions different from each other, detects a write state of each of the simulated reference patterns, selects one of the write conditions according to detection results, and writes a plurality of regular reference patterns which become criteria for predetermined processing to be executed on the magnetic disk to the magnetic disk on the selected write condition.

Magnetic disk device and reference pattern writing method of the same preliminary class

A magnetic disk device includes a magnetic disk, a first read element, a second read element, and a controller. In the magnetic disk, first servo information is written. The controller controls the servo writing of second servo information on the magnetic disk, based on the first servo information. In addition, the controller controls acquisition of the first servo information by the first read element. The controller switches a read element to be used to control the servo writing from the first read element to the second read element based on quality of the first servo information acquired by the first read element.

Magnetic disk device

Embodiments of the present invention help to prevent, in a magnetic head slider adapted to be able to control flying height of a head element, the occurrence of excessive frictional force, even in case of contact with a magnetic disk, and suppress vibration of the slider. According to one embodiment, an air bearing surface of a magnetic head slider includes a deep groove, a shallow-trench rail about 100 nm higher than the deep groove, a rear end shoulder, two leading end pads about 1 &#x3bc;m higher than the deep groove, a trailing end pad about 970-995 nm higher than the deep groove, and an element pad about 5-30 nm higher than the trailing end pad and flush with the leading end pads. A head element includes a magnetic head element and a heater. The element pad has an area of 50-500 &#x3bc;m, and the magnetic head element is disposed near a central section of the element pad.

Magnetic head slider and magnetic disk drive

In one embodiment, the slider surface comprises an inflow shallow groove part formed in a stepped manner, two inflow end pads, a negative pressure generating deep groove part, an outflow shallow deep groove part formed on the air outflow end side, an outflow end pad provided on the outflow shallow groove part, and a trimmed part (flying height reducing portion) in which the outflow end pad is extended to the air outflow end while being narrowed in width. A magnetic head is formed on the trimmed part on the outflow side of the outflow end pad, and the trimmed part between the magnetic head and the outflow end is formed with a groove portion in the air outflow direction.

Magnetic head slider with groove formed in reduced-width portion of trailing pad between head and trailing edge

This magnetic recording medium is characterized in that in the magnetic recording medium having a magnetic layer on a non-magnetic substrate by intercalating at least an under layer, the proportion of functional groups per 100 carbon atoms in a diamond-like carbon protective layer mainly composed of carbon for protecting the magnetic layer exceeds 20%. The bonding force between the protective layer and the lubricating layer of the magnetic recording medium is increased so that under high speed rotation, a decrease in the lubricating layer is not caused so as to provide a magnetic recording apparatus having high reliability.

Magnetic recording medium, the manufacturing method and magnetic recording apparatus using the same

A magnetic head slider in which a leading pad is projected in a thicknesswise direction of the slider, in comparison with a trailing pad so as to reduce vibration caused by contact between a flat medium surface of a disc and the slider carrying thereon a magnetic head, to reduce variation in flying height caused by wavy unevenness of the medium surface, and to reduce variation in atmospheric pressure around the slider, thereby it is possible to enhance the recording density and the reliability of the magnetic head slider while reducing the costs thereof. Further, a magnetic disc unit using the above-mentioned magnetic head slider.

Magnetic head slider and magnetic disc unit

To provide an atomic force microscopy which allows the measurement of the configuration of a surface being measured by using the phenomenon observed between the surface being measured and a probe approaching thereto at very fine distance. By selecting the material of the tip surface of said probe such that the surface energy of said probe tip becomes less than the interface energy between the tip surface and the surface being measured, thereby the surface configuration of soft body, or soft fouling adhered to the body surface can be measured. A method of measuring the surface configuration and a method of producing magnetic recording medium using the same are also provided.

Atomic force microscopy, method of measuring surface configuration using the same, and method of producing magnetic recording medium

A head slider has small friction force even if the head slider comes in contact with a magnetic disk having a smooth surface at high speed. The vibration is also low and wear resistance is high. The head slider is provided with plural air bearing surfaces for floating over the magnetic disk or one or more lubricant bearing surfaces for smoothly gliding over the magnetic disk. A slope angle on the front side of the bearing surface in the traveling direction of the head slider is larger than a slope angle on the rear side of the bearing surface in the vicinity of a contact part of the bearing surface that may come in contact with the magnetic disk.

Magnetic head slider and magnetic head slider assembly having a leading slope angle smaller than a trailing slope angle

A magnetic disk drive having a magnetic disk, a spindle motor for rotating the magnetic disk, a magnetic head slider for recording or reproducing data onto or from the magnetic disk and a housing. A control circuit system is provided for controlling the head slider so that the head slider is positioned on the magnetic disk plane when the magnetic disk is rotating, and the head slider is saved to outside the magnetic disk plane when rotation of the magnetic disk is stopped. A lubricant supplier is provided for supplying lubricant to the surface of the magnetic disk. The lubricant supplier contains at least a perfluoropolyether compound having any one of an alcohol group, a cyclic ether group, and an alkyl-ester group at its terminal position as a lubricant, and the lubricant contains the perfluoropolyether compound having a molecular weight sufficient to enable lubrication and no greater than 4000.

Magnetic disk drive

A lubricant which does not splash easily and has an improved property of slidableness, and a magnetic disk using the lubricant are provided. A magnetic disk apparatus featuring a prolonged service life of a stable operation and an excellent record reproduction property is provided by installing the above magnetic disk. The lubricant of the invention contains perfluoropolyether expressed by the following general formula, in which a component of its molecular weights less than 1000 is smaller than 10 wt. %, a component of its molecular weights not less than 7000 is smaller than 15 wt. %, a ratio between a weight average molecular weight and a numeric average molecular weight is 1.5 or less, and a substitution ratio of its terminal functional group is not less than 90%:R&#x2014;CFO&#x2014;[&#x2014;(CFCFO)&#x2014;&#x2014;(CFO)&#x2014;&#x2014;]&#x2014;CF&#x2014;R&#x2003;&#x2003;(1),where R1 and R2 are univalent organic groups, m and n are positive integers. Further for the magnetic disk which rotates at a speed of 10000 rpm or more, a lubricant containing a perfluoropolyether expressed by the following general formula is used, in which its numeric average molecular weight is not less than 5500, a component of molecular weights less than 3000 is 15 wt. % or less, a ratio between its weight average molecular weight and its numeric average molecular weight is 1.5 or less, and a substitution ratio of its terminal functional group is not less than 90%:HOCH&#x2014;CFO&#x2014;[&#x2014;CFCFO]&#x2014;&#x2014;[CFO]&#x2014;&#x2014;CF&#x2014;CHOH&#x2003;&#x2003;(2),where m and n are positive integers.

Lubricant, magnetic disk and magnetic disk apparatus

A low cost and highly reliable lubricating technique is realized by using a lubricant having an average molecular weight in the range of 900 to 2500. The lubricant is efficiently supplied to inner portions of a magnetic disk apparatus utilizing heat generated during operation of the apparatus. The method of assembling the apparatus is not affected since it is not necessary to provide a separate lubricant supply mechanism.

Magnetic disc apparatus and its fabricating method

Hard disk drive utilizing second lubricant over a first lubricant having a phosophezine group

The object of this invention is to provide a magnetic disk which has an excellent durability even with a protective film having a small film thickness of 4 nm or less. The magnetic disk of this invention is a magnetic disk comprising a non-magnetic substrate and, provided thereon, a magnetic metal film, carbon protective film and fluorine-containing lubricant film, wherein the carbon protective film is a DLC film having a film thickness of 4 nm or less and the ratio of infrared absorption intensity resulting from the C&mdash;H bond near 2,920 cm determined by FT-IR using ATR to infrared absorption intensity resulting from the C&mdash;F bond of the lubricant film is 0.035-0.060.

Magnetic disk having ultrathin carbon protective film and magnetic disk apparatus

A magnetic disk drive having a small decrease in lubricant film thickness on the surface of the magnetic disk and a superior sliding reliability between the magnetic head and the magnetic disk surface. Perfluoropolyether is supplied as the lubricant onto the surface of the magnetic disk using heat and air flow by applying perfluoropolyether onto the surface of a suspension, or impregnating perfluoropolyether into a filter. The lubricant contains perfluoropolyether having a molecular weight sufficient to enable lubrication and smaller than 4000 by at least 40%.

Magnetic disk drive with supply of perfluoropolyether as lubricant

A head element is made into contact with the surface of a recording medium so as to realize a float-up degree of 5 nm. Accordingly, a slider incorporating the head element for recording and reproducing data to and from the recording medium is provided thereon with a plurality of pads having step parts, and one of the plurality of pads, on which the head element is mounted, has a height which is less than that of the other pads. Thus, the pads other than the pad on which the head element is mounted are floated up while the pad on which the head element is mounted is stably made into contact with the surface of the recoding medium by means of a meniscus suction force and a damping action of lubricant applied on the surface of the recording medium.

Slider capable of reducing distance between head element and recording medium, and recording apparatus incorporating same

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Ninomiya, Japan

Hiroshi Tani