Clock jitter in a servo-derived clocking scheme for magnetic disk drives

Friction/stiction behaviour of ultrahigh-density magnetic disk drives can be controlled by controlling the size and shape of the laser bumps. Tribological behaviour of laser-textured disk surfaces depends on the size and shape of the laser bumps, bump density and operating conditions. In this study, theoretical and experimental analyses have been carried out on nine different laser-textured disk surfaces. Stiction and friction experiments have been carried out on sombrero, V-type and W-type laser-textured disks and these results are compared with theoretical results. A good correlation is obtained between experimental and theoretical results. The effect of laser bump uniformity on critical number of bumps required to prevent plastic deformation and stiction has also been studied.

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Magnetic disk drives

Introduction to Digital Audio ◽

10.4324/9780080495811-10 ◽

2013 ◽

pp. 337-358

Keyword(s):

Disk Drives ◽

Magnetic Disk

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Investigation of Photo-Lithographically Precoded Servo Pattern for High Track-Density Magnetic Disk Drives

Advances in Information Storage Systems ◽

10.1142/9789812831415_0017 ◽

1995 ◽

pp. 263-274

Author(s):

K. Akagi ◽

Y. Miyamura ◽

M. Suzuki

Keyword(s):

Track Density ◽

Disk Drives ◽

Magnetic Disk ◽

High Track

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Depletion of Moleculary Thin Lubricant Under Flying Head in Hard Disk Drives

ASME/STLE 2007 International Joint Tribology Conference, Parts A and B ◽

10.1115/ijtc2007-44224 ◽

2007 ◽

Author(s):

Kenji Yanagisawa ◽

Youichi Kawakubo ◽

Masato Yoshino

Keyword(s):

Thin Film ◽

Hard Disk Drives ◽

Hard Disk ◽

Lubricant Film ◽

Simulation Program ◽

Disk Drives ◽

Lubricant Thickness ◽

Magnetic Disk ◽

Lubricant Depletion ◽

Lubricant Films

In Hard Disk Drives, lubricants are very important materials to reduce head and disk wear. Therefore, it is necessary to know the lubricant depletion under flying heads. Lubricant depletion due to flying heads has been studied experimentally. We developed simulation program to calculate numerically the change in lubricant thickness under a flying head on a thin-film magnetic disk from 10nm thick lubricant film. In recent HDDs, the lubricants thickness has become molecularly thin and polar lubricants have been used. In this paper, we took account of thickness-dependent lubricants diffusion and viscosity in our simulations to calculate a 1.2 nm thick polar lubricant film used in recent HDDs. The simulated results considering the thickness-dependent diffusion and viscosity showed that depletion was small in molecularly thin lubricant films. We considered it necessary to include thickness-dependent diffusion and viscosity in lubricant depletion simulation.

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Evaluation of capacitance displacement sensors used for slider-disk spacing measurements in magnetic disk drives

IEEE Transactions on Magnetics ◽

10.1109/20.179550 ◽

1992 ◽

Vol 28 (5) ◽

pp. 2542-2544 ◽

Cited By ~ 2

Author(s):

M. Suk ◽

T. Ishii ◽

D.B. Bogy

Keyword(s):

Disk Drives ◽

Magnetic Disk ◽

Displacement Sensors ◽

Disk Spacing

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Adaptive Seeking Control for Magnetic Disk Drives.

JSME International Journal Series C ◽

10.1299/jsmec.43.300 ◽

2000 ◽

Vol 43 (2) ◽

pp. 300-305 ◽

Cited By ~ 4

Author(s):

Masahito KOBAYASHI ◽

Takashi YAMAGUCHI ◽

Hiromu HIRAI

Keyword(s):

Disk Drives ◽

Magnetic Disk

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Basic Design Guide Proposal on Nanometer Flying-Height Slider for Small Magnetic Disk Drives

Journal of Robotics and Mechatronics ◽

10.20965/jrm.2005.p0509 ◽

2005 ◽

Vol 17 (5) ◽

pp. 509-516

Author(s):

Yoshinori Takeuchi ◽

◽

Katsuyuki Tanaka ◽

Keyword(s):

Negative Pressure ◽

Flying Height ◽

Constant Density ◽

Basic Design ◽

Disk Drives ◽

Magnetic Media ◽

Magnetic Disk ◽

Design Guide ◽

Sudden Decrease ◽

Yaw Angle

We propose a basic design guide to design a very low spacing slider for small magnetic disk drives. The design features; (1) A multipad or side-step slider to avoid a sudden decrease in flying height due to the yaw angle of the swing actuator. (2) The slider must be as small as possible to be stable because the very low flying height makes the slider tend to vibrate unstably. (3) High spacing mode must be avoided to stabilize the negative-pressure slider used in constant density recording (CDR) suitable for high-density magnetic media.

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