Abstract: According to one embodiment, a disk drive has a magnetic disk and a magnetic head having a spin-torque oscillator. The disk drive further has a head amplifier IC configured to supply a write signal and a drive signal to the magnetic head. The write signal corresponds to write data. The drive signal is supplied to generate a high-frequency magnetic field. The head amplifier IC continuously supplies a drive signal of normal level to the spin-torque oscillator, and supplies a drive signal of high level higher than the normal level, only for a prescribed time after the polarity inversion of the write signal.

Abstract: A control circuit board is opposed to an outer surface of a case in the form of a rectangular box, and an connector cable, which has connector terminals connectable with an external device, extends from the circuit board. The control circuit board has a plurality of first connector pads with a first property and a plurality of second connector pads with a second property different from the first property, the first and second connector pads being arranged side by side on the control circuit board. The connector cable has a proximal end portion connected to at least one type, among the first and second connector pads, and the connector terminals including a plurality of connector terminals connecting with the at least one type of connector pads to which the proximal end portion is connected.

Abstract: In a disk drive that performs perpendicular magnetic recording, the read/write channel has a sync mark generator. The sync mark generator generates a second sync mark before the read/write channel operates to write data on a disk. The second sync mark has a bit pattern including a series of bits representing positive polarity and a series of bits representing negative polarity. The series of bits, which is longer than the other, has a bit length that is at least 50% but less than 85% of the total bit length of the second sync mark.

Abstract: A disk drive includes a casing which houses a disk-shaped recording medium, a drive motor which holds and rotates the recording medium, a head which performs read/write operations, a head actuator movably supporting the head to move the head relative to the recording medium, and a board unit connected to the head actuator. The board unit has a board main body arranged on the inner surface of the casing and at least one capacitor, mounted on the board main body for supplying power to perform a retracting operation for permitting the head actuator to move the head to a retracted position.

Abstract: There is disclosed a servo writing method in which servo data is recorded by a perpendicular magnetic recording system. In the servo writing method, at the time of perpendicular magnetic recording of the servo data on a disk, a servo writing operation is executed including an offset process set based on the hard-easy transition shift (HETS) phenomenon.

Abstract: There is disclosed a servo writing method in which servo data is recorded by a perpendicular magnetic recording system. In the servo writing method, at the time of perpendicular magnetic recording of the servo data on a disk, a servo writing operation is executed including an offset process set based on the hard-easy transition shift (HETS) phenomenon.

Abstract: A perpendicular magnetic recording disk drive is discloses which performs a head positioning control operation effectively against a hard easy transition shift (HETS) phenomenon. In the disk drive, a CPU performs an offset correcting operation in positioning control mode after a seek operation, using an offset value set on the basis of the HETS phenomenon from a memory when data is recorded.

Abstract: A disk drive includes a case which contains a disk-shaped recording medium, drive motor, head, and head actuator. The drive motor supports and rotates the recording medium. The head processes information for the recording medium. The head actuator supports the head for movement and moves the head with respect to the recording medium. A control circuit board is mounted to the outer surface of the case. The control circuit board has a plurality of connector pads for connection with external equipment. The connector pads are arranged side by side and exposed on the outer surface of the control circuit board. The connector pads are positioned on a side of the control circuit board adjacent the head actuator.

Abstract: A control circuit board is opposed to an outer surface of a case in the form of a rectangular box, and an connector cable, which has connector terminals connectable with an external device, extends from the circuit board. The control circuit board has a plurality of first connector pads with a first property and a plurality of second connector pads with a second property different from the first property, the first and second connector pads being arranged side by side on the control circuit board. The connector cable has a proximal end portion connected to at least one type, among the first and second connector pads, and the connector terminals including a plurality of connector terminals connecting with the at least one type of connector pads to which the proximal end portion is connected.

Abstract: A disk drive includes a casing which houses a disk-shaped recording medium, a drive motor which holds and rotates the recording medium, a head which performs read/write operations, a head actuator movably supporting the head to move the head relative to the recording medium, and a board unit connected to the head actuator. The board unit has a board main body arranged on the inner surface of the casing and at least one capacitor, mounted on the board main body for supplying power to perform a retracting operation for permitting the head actuator to move the head to a retracted position.

Abstract: A disk drive which includes a head amplifier having a function of degaussing a magnetic head effective to suppression of an EAW phenomenon is disclosed. The head amplifier includes a degaussing controller which performs switching from write operation to degaussing operation, a write driver which outputs degaussing current necessary for the degaussing operation, and a current control unit which sets a current waveform of the degaussing current.

Abstract: Disclosed is a cellular phone terminal including: a processing part including a transmitting/receiving part; a hard disc drive capable of holding information processable by the processing part and information having been processed by the processing part; a hard disc drive control part interposed between and connected to the processing part and the hard disc drive and controlling transfer of information from the processing part to the hard disc drive and transfer of information from the hard disc drive to the processing part; and a recording preventing part provided in the hard disc drive control part and preventing information to be transferred from the processing part to the hard disc drive from being recorded on the hard disc drive.

Abstract: A portable information terminal has a main body portion and a cover portion. A main body portion has a key switches and a microphone. A cover portion has an open state and a close state. The key switches enable to be operated in the open state. A hard disc drive (HDD) as magnetic disc device has a heat generating board and is disposed in the main body portion so that the heat generating board faces a side of the front surface. A sound insulator is disposed in the main body portion so that the sound insulator insulates sound of the HDD from the microphone.

Abstract: An open/closed state detecting unit detects in which one of an open state, a closed state, and an intermediate state a portable information terminal is, and the operation of a magnetic disk is controlled based on the detection result. Opening/closing a cover relative to a main body generates an impact. Since this impact occurs when the cover shifts from the intermediate state to the open state or to the closed state, detecting the open/closed state of the cover by the open/closed state detecting unit and controlling the magnetic disk according to the detection result makes it possible to protect the magnetic disk from the impact.

Abstract: A servo track write method is disclosed in which, in a disk drive of a perpendicular magnetic recording system, servo data is written with the use of a single magnetic pole type head of the disk drive itself. In this method, the servo data is recorded on a disk in those servo areas with the use of the single magnetic hole type head mounted on the disk drive. A head mounted as the single magnetic pole type head is position-controlled relative to the servo area by a servo track writer. The servo data is recorded with perpendicular magnetization under a recording magnetic field from the single magnetic pole type head in accordance with the magnetic pole thickness of the single magnetic pole type head.

Abstract: A disk drive including a write head for perpendicular magnetic recording is disclosed. The write head includes a main recording magnetic pole which applies a perpendicular recording magnetic field onto a disk medium and an auxiliary magnetic pole, and has a structure in which the auxiliary magnetic pole is arranged on a rear end side of the main recording magnetic pole through a small gap there between in a relative movement direction of this write head. this write head.

Abstract: There is disclosed a servo writing method in which servo data is recorded by a perpendicular magnetic recording system. In the servo writing method, at the time of perpendicular magnetic recording of the servo data on a disk, a servo writing operation is executed including an offset process set based on the hard-easy transition shift (HETS) phenomenon.

Abstract: In a disk drive that performs perpendicular magnetic recording, the read/write channel has a sync mark generator. The sync mark generator generates a second sync mark before the read/write channel operates to write data on a disk. The second sync mark has a bit pattern including a series of bits representing positive polarity and a series of bits representing negative polarity. The series of bits, which is longer than the other, has a bit length that is at least 50% but less than 85% of the total bit length of the second sync mark.

Abstract: A perpendicular magnetic recording disk drive is discloses which performs a head positioning control operation effectively against a hard easy transition shift (HETS) phenomenon. In the disk drive, a CPU performs an offset correcting operation in positioning control mode after a seek operation, using an offset value set on the basis of the HETS phenomenon from a memory when data is recorded.

Abstract: Provided is a block heater structured so as to be capable of maintaining the thermal transmission and thermal effect, as well as the mechanical strength, in a prescribed state in the respective components upon assembling the sheathed heater, cylindrical body, cap, and so on of the engine cooling water antifreeze block heater. This block heater has a sheathed heater 2 having a heating element 18 embedded in heat-resistant insulation powder 22 inside a sheath 11; a cylindrical body 3 for retaining the back-end portion of the sheathed heater and mounted onto a heater mounting portion of an automotive engine block; and a cap 4 attached to the opposite end of the sheathed heater of this cylindrical body, and structured so as to retain the heater connection end of a cable 5 having a power supply outlet at one end thereof. A gap 30 is provided between the end on the cap side of the cylindrical body and the end on the body side of the cap.