Abstract: Embodiments of the present invention precisely measure clearance variation by temperature change using a value in a RW channel. In an embodiment of the present invention, an HDD measures resolution by signals in a RW channel. The measured resolution shows variations depending on temperature according to two factors. One factor is the clearance variation depending on the temperature and the other is the variation in operational property of the RW channel depending on the temperature. The HDD compensates for the temperature variation of the resolution according to the two factors. The HDD uses two kinds of sensed temperature. One corresponds to the temperature inside an enclosure in which head sliders are provided and the other corresponds to the temperature of the chip in which the RW channel is implemented. Sensing the drive temperature and the channel temperature independently achieves precise compensation for the variation in the measured resolution caused by clearance variation and channel property.

Abstract: Embodiments in accordance with the present invention reduce the number of errors caused by the aged deterioration of a heater for adjusting the clearance between a head and a disk. According to one embodiment, a thermal fly height control (TFC) controller executes the measurement of a resistance value of a heater in a predetermined timing. The TFC controller judges whether or not the measured resistance value falls within a predetermined reference range. If the measured resistance value falls within the reference range, the processing ends without performing any other processing. If the measured resistance value goes out of the reference range, the TFC controller executes error handling processing in response to a resistance failure. As one of the error handling processing, the TFC controller notifies the host that the abnormality (resistance failure) has been detected in the resistance value of the TFC heater.

Abstract: A method for manufacturing a magnetic head that is effective for the suppression of thermal protrusion. The magnetic head includes SiO2, Si nitride, or Si oxide as a coil insulator having a low coefficient of thermal expansion and high workability. The coil insulator is arranged at a position away from the air bearing surface and the air bearing surface is made of alumina, making slider processing easy.

Abstract: In a magnetic disk unit, the flying height margin of a magnetic recording element part during recording is reduced, whereby improvement in recording density and increase in capacity or decrease in size of the unit is realized. In one embodiment, a magnetic disk unit has a magnetic disk arranged in a freely rotational manner and a magnetic head slider disposed to face a surface of the magnetic disk, and generates air flow between the magnetic disk and the magnetic head slider for flying, and records data using a magnetic recording element. The magnetic head slider has a slider substrate part and a thin-film head part formed on the slider substrate part using a thin-film process. The thin-film head part has an insulating member, a magnetic recording element provided in the insulating member, and a heat radiation member for radiating heat generated by the magnetic recording element from lateral regions of the magnetic recording element to the slider substrate part.

Abstract: According to one embodiment, a magnetic head includes a write element, a read element, and a heating element disposed between the write element and the read element. When power is applied to the heating element, either the read element or the write element projects beyond a plane of an air-bearing surface (ABS) of the magnetic head, and when power is not applied to the heating element, a portion of the ABS of the magnetic head facing a magnetic disk close to the heating element has a concave shape. In another embodiment, when power is applied to the heating element, at least one of a portion of the read element and a portion of the write element approaches a magnetic disk, and when power is not applied to the heating element, a portion of the ABS of the magnetic head facing a magnetic disk close to the heating element has a concave shape.

Abstract: Embodiments of the invention achieve a decrease in electric power consumption while ensuring high recording density and high reliability in a magnetic disk apparatus. In one embodiment, a magnetic disk apparatus comprises a rotatable magnetic disk and a magnetic head slider to be able to fly above a surface of the magnetic disk. The magnetic head slider comprises an air bearing surface, by which the magnetic head slider is caused to fly and come near to the rotating surface of the magnetic disk with a predetermined spacing therebetween, recording and reproducing elements to perform at least one of recording on and reproduction from the magnetic disk, and a heating device to adjust a distance between the recording and reproducing elements and the surface of the magnetic disk. The heating device is mounted such that heating thereof causes a part of the air bearing surface to expand and project to increase a distance between the recording and reproducing elements and the surface of the magnetic disk.

Abstract: Embodiments of the invention secure a sufficiently large magnetic field, and deter a protrusion phenomenon of a perpendicular magnetic recording head, causing a problem in implementing a low flying height, while solving problems such as erasure of information in peripheral tracks. In one embodiment, a main pole or a stacked body made up of the main pole, and an auxiliary pole is deposited over an underlayer formed on a substrate so as to be in contact with the underlayer. On top of the main pole or the stacked body, there is deposited a coil, a return pole, and a read element in that order, thereby fabricating a perpendicular magnetic recording head.

Abstract: A suspension having a magnetic head assembly 1 mounted thereon is provided, wherein the magnetic head assembly comprises: a write head 1-2; a read head 1-1; and a resistive heating element 1-3 for controlling the flying heights of the magnetic heads, wherein the wires HTx and GTx for the resistive heating element is disposed such that they sandwich the wires RxX and RxY for the read head. The wires for the resistive heating element may be disposed between the wires for the write head and the wires for the read head. Furthermore, the waveform of the current or voltage to the resistive heating element has a time constant of 1 ?sec or more, the resistive heating element having wires disposed near the wires of the read head.

Abstract: Embodiments of the invention improve the power consumption and response speed of a heater for the gap flying height (hg) adjustment, to minimize an influence that the heater has on a life of a read element, and to provide a heater having resistance lines reduced in breaking and ensuring higher reliability. In one embodiment, a read/write element is formed near an air bearing surface (ABS) on a slider, and the circumference of the read/write element is filled with alumina. The read/write element includes an upper magnetic pole piece, a lower magnetic pole piece, a coil, and a resist filling around the coil, and a read element (MR) for performing reading, and an upper shield and lower shield for protecting the read element from an external magnetic field. A heater for adjusting the flying height is provided between the slider and the read/write element but near the read/write element.

Abstract: Embodiments of the present invention help to improve the cost, mountability, and reliability of a magnetic disk drive that regulates a fly height of a magnetic head slider correspondingly to the operating altitude of the drive by using an air pressure sensor and a heater. According to one embodiment, a preamplifier is a semiconductor chip formed by three-dimensionally laminating thin film circuits on a bulk silicon wafer. An air pressure sensor is integrally formed on the semiconductor chip through a semiconductor process. The air pressure sensor is configured to include an isolating cavity, a diaphragm that deflecting in response to a change in a pressure difference between the isolating cavity and the outside, and lower and upper electrodes and for detecting variation in electrostatic capacitance. The preamplifier including the air pressure sensor integrally formed therein is attached to a flexible printed cable (FPC) to oppose the FPC.

Abstract: Embodiments of the invention provide a magnetic disk device which lowers the cost, maintains reliability by compensating the thermal dent or protuberance caused by a change in the environmental temperature, makes it possible to increase the recording density by decreasing the floating amount of the slider, to increase the capacity of the device or to decrease the size thereof. In one embodiment, a magnetic disk device comprises a magnetic disk, a magnetic head slider, and a drive unit for moving the magnetic head slider, wherein an air stream is generated between the magnetic disk that rotates and the magnetic head slider to effect the recording or the reproduction in a state where the magnetic head slider is floating. The magnetic head slider includes a slider substrate portion and a thin-film head portion that has recording and reproducing elements, a metal film, and an insulating film formed on the slider substrate portion and constituting a slider-floating plane along with the slider substrate portion.

Abstract: Embodiments of the present invention provide a technique for projecting both a write element portion in writing and a read element portion in reading, and controlling a projecting distance of each write element and read element. According to one embodiment, a light absorbing member and a thermally expanding member are formed near a read element, and light is irradiated to the light absorbing member, thereby a read element is projected. Alternatively, light absorbing members, which absorb light having different wavelengths from each other, and thermally expanding members are formed near a write element and near the read element respectively, and a wavelength or intensity of light to be irradiated is changed, thereby a projecting distance of each of the write element and the read element is individually optionally controlled.

Abstract: Embodiments of the invention achieve a decrease in electric power consumption while ensuring high recording density and high reliability in a magnetic disk apparatus. In one embodiment, a magnetic disk apparatus comprises a rotatable magnetic disk and a magnetic head slider to be able to fly above a surface of the magnetic disk. The magnetic head slider comprises an air bearing surface, by which the magnetic head slider is caused to fly and come near to the rotating surface of the magnetic disk with a predetermined spacing therebetween, recording and reproducing elements to perform at least one of recording on and reproduction from the magnetic disk, and a heating device to adjust a distance between the recording and reproducing elements and the surface of the magnetic disk. The heating device is mounted such that heating thereof causes a part of the air bearing surface to expand and project to increase a distance between the recording and reproducing elements and the surface of the magnetic disk.

Abstract: Embodiments of the present invention precisely measure clearance variation by temperature change using a value in a RW channel. In an embodiment of the present invention, an HDD measures resolution by signals in a RW channel. The measured resolution shows variations depending on temperature according to two factors. One factor is the clearance variation depending on the temperature and the other is the variation in operational property of the RW channel depending on the temperature. The HDD compensates for the temperature variation of the resolution according to the two factors. The HDD uses two kinds of sensed temperature. One corresponds to the temperature inside an enclosure in which head sliders are provided and the other corresponds to the temperature of the chip in which the RW channel is implemented. Sensing the drive temperature and the channel temperature independently achieves precise compensation for the variation in the measured resolution caused by clearance variation and channel property.

Abstract: Embodiments of the invention achieve a decrease in electric power consumption while ensuring high recording density and high reliability in a magnetic disk apparatus. In one embodiment, a magnetic disk apparatus comprises a rotatable magnetic disk and a magnetic head slider to be able to fly above a surface of the magnetic disk. The magnetic head slider comprises an air bearing surface, by which the magnetic head slider is caused to fly and come near to the rotating surface of the magnetic disk with a predetermined spacing therebetween, recording and reproducing elements to perform at least one of recording on and reproduction from the magnetic disk, and a heating device to adjust a distance between the recording and reproducing elements and the surface of the magnetic disk. The heating device is mounted such that heating thereof causes a part of the air bearing surface to expand and project to increase a distance between the recording and reproducing elements and the surface of the magnetic disk.

Abstract: Embodiments of the present invention help to precisely control the clearance between a head and disk for the pressure without using a barometric sensor. In an embodiment of the present invention, an HDD determines a clearance from variations in operational parameters, and further determines a variation in pressure by deducting the clearance variation caused by a variation in temperature from the clearance. When the HDD controls the clearance in accordance with the pressure change, the HDD checks for head-disk contact. The accuracy and reliability in pressure measurement (clearance measurement) using operational parameters are not high. Therefore, confirming the pressure measurement by the presence or absence of head-disk contact eliminates head-disk contact in the following read/write operation to attain a securer margin for the clearance.

Abstract: Embodiments of the invention provide a magnetic disk device which improves the shielding function for the magnetic heads while maintaining a form factor having an inexpensive constitution. In one embodiment, a magnetic disk device comprises a rotary disk-type magnetic disk; a magnetic head for recording or reproducing information; a magnetic head support mechanism for supporting the magnetic head; a shroud having an opening in which the magnetic head support mechanism is inserted, and surrounding the outer circumference of the magnetic disk; and a housing. The housing includes a base and a cover, and accommodates the magnetic disk, the magnetic head, the magnetic head support mechanism and the shroud. The base is constituted by using a nonmagnetic material and the shroud is constituted by using a magnetic material.

Abstract: In a magnetic disk apparatus, mounting of plural heating elements to a magnetic head slider is permitted. Thermally assisted magnetic recording from inner to outer surface is permitted at a small amount of power consumption. In one embodiment, the magnetic disk apparatus has a magnetic disk on which magnetic information is recorded, a magnetic head slider having an air bearing surface for floating from the magnetic disk in proximity thereto, and a rotary actuator moving over the disk arcuately while supporting the magnetic head slider by a suspension. A recording element acting to record magnetic information on the magnetic disk, a playback element acting to play back the magnetic information recorded on the magnetic disk, and plural heating elements acting to locally heat the magnetic disk are carried on the magnetic head slider.

Abstract: Embodiments of the invention appropriately control the flying height of a magnetic head slider as necessary without making the magnetic head slider touch the magnetic disk. In one embodiment, when a magnetic disk drive is started, the level of electric power predefined for the ordinary temperature (room temperature) is read in from the internal memory of an MPU. A temperature sensor measures the internal temperature of the magnetic disk drive and sends it to the MPU. According to the temperature sent from the temperature sensor, the MPU calculates the level of electric power which should be applied to a flying height adjustment structure. According to the calculated electric power, the MPU increases or decreases the electric power applied to the flying height adjustment structure. At a flying height controlled (corrected) by the flying height adjustment structure, a magnetic head slider performs read/write on a magnetic disk.

Abstract: In a magnetic disk device, cost reduction is designed by improving productivity, and increase in recording density and increase in capacity of the device or size reduction are designed with reliability being ensured. In one embodiment, a magnetic disk device has a magnetic disk arranged rotatably, a magnetic head slider arranged in a manner of facing a surface of the magnetic disk, and a driving device for moving the magnetic head slider in a radial direction of the surface of the magnetic disk. The magnetic head slider has a silicon slider-substrate-portion and a thin-film head portion which is formed on the slider substrate portion using a thin-film process and forms an air-bearing surface along with the slider substrate portion.