International Business Machines Corporation

Shinji Ueno

Isao Yoneda

Fuminori Sai

Hiroshi Uchiike

Kenji Ogasawara

Nobuyuki Kitazaki

Yoshiro Amano

Masahiro Shimizu

Takashi Nakamura

Haruo Andoh

Yuji Yokoe

Shusuke Kurihara

Kenja Ogasawara

Kenjo Ogasawara

Yasuhiro Iihara

Keiichi Ohtsubo

Hirotoshi Tanimura

Kazunari Tsuchimto

Yoshihiko Aoki

An electronic package in which an electronic component (e.g., LSI chip module) includes a heat dissipating surface (e.g., metal layer) and is positioned on a printed wiring board such that the heat dissipating surface is located adjacent a heat transfer area on the board. The heat transfer area is in the form of a pattern of solder-applied areas from which the solder bonds to the heat dissipating layer to provide heat transfer from the component to the board. Through holes may also be used in the board to increase heat removal.

Electronic package with plurality of solder-applied areas providing heat transfer

A disk drive with means to prevent accidental landing of a head/slider on the disk surface is described. In one embodiment a shock sensor is provided to sense external shocks received by the mechanism. During loading (positioning) of the actuator bearing the head/slider over the disk, if a shock is sensed, loading is stopped and an immediate unloading is performed to return the actuator to the withdrawn position. In another embodiment the unload operation is performed when the rotational speed of the disk is changed. In another embodiment the unload operation is performed when the rotational speed of the disk drops below a threshold. A circuit and method for detecting when the rotational speed of the disk drops below a threshold is also provided. The unloading in the various embodiments may be performed using velocity control or without velocity control.

Disk drive with actuator load/unload controller

The present invention provides a disk drive, a loading/unloading apparatus, and a method for controlling the apparatus, capable of improving the reliability of data by performing stable speed control. A disk drive comprises a VCM spindle driver for rotating a disk, a magnetic head, an actuator mechanism for moving a head slider having the magnetic head to a position above the surface of the magnetic disk and an unloaded position, a ramp block, and a CPU/HDC for performing the speed control of an actuator and the calibration control for detecting the offset and dynamic range of an AD converter before the speed control and controlling the operation for reading or writing data from or into the disk, which increases a rectangular current value to be applied to a voice coil while successively changing codes, measures an offset in accordance with the AD converter value for each current value, and moreover measures a dynamic range by deciding a nonlinear area when the difference between the expected value and measured value of the AD converter becomes a predetermined value or more.

Disk drive loading/unloading apparatus and method for controlling the apparatus

The invention relates to a magnetic recording device which can be used at a reduced atmospheric pressure without having the head/slider assembly stick to the disk. A method of the present invention for controlling the operation of a disk drive device in reduced atmospheric pressure where a read/write head mounted on a head support arm flies above the surface of a rotating recording disk. The head support arm is moved along a radial direction of the recording disk to position the read/write head to one of cylinder positions of the recording disk. The method comprises steps of (i) detecting a value of the reduced atmospheric pressure during a power on reset period before a read/write period, (ii) storing information indicating whether the detected value of atmospheric pressure is lower than a threshold value, and (iii) accessing, during the read/write period, the stored information to determine whether an operation for lowering a flying height of the read/write head to a height which is lower than a height for the read/write operation should be inhibited.

Disk drive device and method for controlling the same

The present invention is an apparatus and method to reliably unload a head slider from a recording medium. Transistor Tr5 is on. If the main power supply Vdd is turned off at time t1, Tr1, Tr2, and D1 are turned off and the level of the control signal Ret becomes higher than the threshold voltage Vth of Tr3 and Tr4, turning on Tr3 and Tr4. C1 also starts to discharge. The control signal InRet changes to a 'L'-level, and the control signal OutRet remains to be at the 'L'-level. This allows the IR driver to feed a negative-polarity VCM current through the voice coil to preliminarily move the head arm in the direction opposite to the unload direction. Then, at time t2 when the level of Ret becomes equal to or lower than Vth, both InRet and OutRet change to a 'H'-level, the IR driver becomes inoperative, and the OR driver feeds a positive-polarity VCM current through the voice coil to reverse the moving direction of the head arm.

Head mechanism control apparatus, disk drive unit, and method of

The invention relates to a head mechanism control apparatus for magnetic recording device which ensures that the transducer head has been unloaded in a head unloading operation. A head slider having a transducer head is mounted on a head arm and is unloaded from the disk by the swinging of the head arm. The retract position is at the limit portion of the swingable range of the head arm. When the head slider is successfully unloaded to the retract position, a drive force applied to the head arm in the unload direction causes little movement of the head arm. After an unloading is performed, a position check drive force is applied to the head arm and the moving speed of the head slider is detected. Based on the moving speed, it is judged whether the head slider has been unloaded to the retract position. If the head slider has not been unloaded to the retract position, re-unloading is performed for moving the head slider to the retract position.

Head mechanism control apparatus, disk drive, and head unload control

A disk drive has an error recovery procedure with a plurality of ERP steps. An unused capacity of an alternate area on a disk for reassigning data is determined. While executing the error recovery procedure, an execution condition for reassigning data is changed based unused capacity of the alternate area. Data is reassigned to the alternate area in response to the execution condition. This prevents the early loss of the alternate area.

Growing community of inventors

Fujisawa, Japan

Shinji Ueno