Abstract: A perpendicular magnetic recording medium including a soft magnetic underlayer. The perpendicular magnetic recording medium includes: a lower structural body including an anti-ferromagnetic layer; a first soft magnetic underlayer, a non-magnetic layer, and a second soft magnetic underlayer sequentially formed on the anti-ferromagnetic layer, where the thickness ratio of the second soft magnetic underlayer to that of the first soft magnetic underlayer is designed to be within specific range; and a recording layer formed on the second soft magnetic underlayer. Therefore, noise generated on the soft magnetic underlayer due to external magnetic fields of a magnetic head and a voice coil motor can be reduced greatly.

Abstract: A method and an apparatus for improving performance of a hard disk drive at low temperature are provided. The method includes: measuring an internal temperature of the hard disk drive; checking whether a measured internal temperature is not more than a predetermined critical temperature; if the measured internal temperature is not more than the predetermined critical temperature, driving a motor of the hard disk drive for a predetermined time and proceeding to the operation of the measuring of the internal temperature of the hard disk drive; and if the measured internal temperature is greater than the predetermined critical temperature, determining that reading/writing operations with respect to the hard disk drive are available.

Abstract: Provided are a hard disk drive (HDD) assembly and a mobile phone employing the HDD assembly. The HDD assembly includes: a HDD including a base member, a cover member, a spindle motor installed on the base member, at least one data storage disk mounted on the spindle motor, and an actuator pivotably installed on the base member and moving a read/write head to a predetermined position on the disk; a printed circuit board (PCB) disposed beside the HDD and operating the HDD; and a mounting bracket mounted on an electronic device while accommodating the HDD and the PCB, and including a first accommodating space adapted to accommodate the HDD and a second accommodating space disposed beside the first accommodating space and adapted to accommodate the PCB.

Abstract: Provided is a hard disk drive (HDD) assembly. The HDD assembly includes: a HDD including a base member, a cover member, a spindle motor, a data storage disk, and an actuator; and a printed circuit board (PCB) disposed beside the HDD and operating the HDD. The HDD assembly can be mounted on an electronic device, for example, a mobile phone. In this case, the HDD assembly is mounted between a main PCB and a back cover of the mobile phone using a first damping pad interposed between the cover member and the main PCB and a second damping pad interposed between the base member and the back cover. The PCB for the HDD is disposed on the main PCB of the mobile phone to be placed beside the HDD.

Abstract: Provided is a magnetic head including a bottom pole, a top pole spaced a predetermined distance apart from the bottom pole, an inductive write coil for forming a magnetic field at the bottom and top poles, and a magnetic shield layer positioned over the top pole.

Abstract: A negative pressure air-bearing slider includes a body flying in a first direction along a track of a disc where information is recorded while being raised to a predetermined height, a plurality of rails provided at the bottom of the body corresponding to a surface of the disc, an air inflow channel arranged at the bottom of the body in the first direction and having an air inflow portion at the leading end portion of the slider and an air exhaust portion at the inside of the body, and a pair of negative pressure recess portions provided at the air exhaust portion of the air inflow channel to be arranged in a second direction perpendicular to the first direction with respect to the air inflow channel. Thus, a constant flying height is maintained in the overall area of a disc. A pitch angle is maintained within an appropriate range in the overall area of a disc. The size of the roll angle is minimized in the overall area of a disc and maintained to be constant.

Abstract: Provided is a magnetic head including a bottom pole, a top pole spaced a predetermined distance apart from the bottom pole, an inductive write coil for forming a magnetic field at the bottom and top poles, and a magnetic shield layer positioned over the top pole.

Abstract: A negative pressure air-bearing slider includes a body flying in a first direction along a track of a disc where information is recorded while being raised to a predetermined height, a plurality of rails provided at the bottom of the body corresponding to a surface of the disc, an air inflow channel arranged at the bottom of the body in the first direction and having an air inflow portion at the leading end portion of the slider and an air exhaust portion at the inside of the body, and a pair of negative pressure recess portions provided at the air exhaust portion of the air inflow channel to be arranged in a second direction perpendicular to the first direction with respect to the air inflow channel. Thus, a constant flying height is maintained in the overall area of a disc. A pitch angle is maintained within an appropriate range in the overall area of a disc. The size of the roll angle is minimized in the overall area of a disc and maintained to be constant.

Abstract: An improved 10-pole 9-slot brushless DC motor used as a spindle motor used in devices, such as a computer hard disk driver or a laser scanner, is provided which reduces cogging torque and improves driving torque. The motor includes a field magnet having an annular permanent magnet which is formed of 10 magnetic poles attached to each other in a radial orientation, for generating a flux field and an armature formed by winding an armature core formed of nine slots and nine salient-poles with windings connected in three phases. Also, the field magnet of the motor is rotated by the rotating magnetic field generated by the armature windings. Since the motor has a short cycle and low cogging torque, the motor is very stable. Also, torque ripple is low and the torque characteristics as a whole are improved, thus achieving high efficiency.