Patent application number | Description | Published |
20090034114 | Magnetic disk drive with head retraction control - Embodiments of the invention improve utility of a magnetic disk drive in which a head is retracted if the magnetic disk drive is in a dropping state. In one embodiment, an HDC/MPU provided in a magnetic disk drive judges whether the magnetic disk drive is in a dropping state based on an output from an acceleration sensor which may detect an acceleration and performs a retraction operation of a head. After the HDC/MPU judges that a drop is occurring, the HDC/MPU detects whether the drop judgment is incorrect according to whether a shock sensor detects a shock occurrence and changes the drop judgment condition based on a detection history of detected incorrect judgments. | 02-05-2009 |
20090201598 | Disc drive device - 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. | 08-13-2009 |
20090300907 | Method for manufacturing magnetic disk unit - Embodiments of the present invention provide a method for manufacturing a magnetic disk unit, the method permitting easy and efficient introduction of a low-density gas into the enclosure. According to one embodiment, an enclosure of the magnetic disk unit has a gas inlet and a gas outlet, each of which is provided with a filter. When the enclosure is filled with helium, the mass flow rate of helium being supplied to the gas inlet is detected and the mass flow rate of helium being supplied to the gas inlet is controlled according to the thus detected mass flow rate of helium. | 12-10-2009 |
20100118442 | HEAD-SLIDER WITH PROTRUSION CONTROL STRUCTURE AND MANUFACTURING METHOD OF THE HEAD-SLIDER WITH PROTRUSION CONTROL STRUCTURE - A head-slider. The head-slider includes a slider and a magnetic-recording head formed on the slider. The magnetic-recording head includes a main pole, a return pole to which a recording magnetic field from the main pole returns, a sensor element, a shield provided between the sensor element and the main pole, and a heater element for adjusting a shape of a flying surface of the magnetic-recording head. The magnetic-recording head further includes a first recess provided at a tip end face of at least one element selected from the group consisting of the return pole and the shield, and a second recess provided on an exposed flying surface and corresponding to the first recess. | 05-13-2010 |
20100123970 | DISK DRIVE, METHOD FOR MEASURING CLEARANCE AND METHOD FOR WRITING SERVO PATTERNS - A disk drive. The disk drive includes a plurality of head-sliders, an actuator, a plurality of clearance adjustment sections, and a controller. Each head-slider includes a slider and a magnetic-recording head on the slider for accessing a disk for storing data. The plurality of head-sliders is secured to the actuator that is configured to move the plurality of head-sliders concurrently. Each clearance adjustment section corresponds to each head-slider of the plurality of head-sliders and adjusts a clearance of the corresponding head-slider. In addition, the controller is configured to position the actuator by servo control with a first head-slider selected from the plurality of head-sliders, to change a clearance of a second head-slider different from the first head-slider by controlling a clearance adjustment section of the second head-slider to bring the second head-slider into contact with a disk, and to detect the contact to measure the clearance of the second head-slider. | 05-20-2010 |
20100149693 | HEAD-SLIDER INCLUDING A LOW-SURFACE-ENERGY FILM THAT PREVENTS LUBRICANT ACCUMULATION, HEAD-ARM ASSEMBLY INCLUDING THE HEAD-SLIDER, AND HARD-DISK DRIVE INCLUDING THE HEAD-ARM ASSEMBLY - The head-slider is configured to receive an air-stream produced by rotation of a magnetic-recording disk and is configured to fly in proximity with a recording surface of the magnetic-recording disk. The head-slider includes a trailing edge on an outflow side of the air-stream, and a disk-facing surface that is configured to face the recording surface of the magnetic-recording disk. A low-surface-energy film is disposed on a portion of a trailing-edge side of the head-slider that is in contact with a boundary between the trailing edge and the disk-facing surface. The low-surface-energy film has a lower surface energy than other portions of the trailing-edge side where the low-surface-energy film is not disposed. | 06-17-2010 |
20110069408 | DISK DRIVE, HEAD-SLIDER AND METHOD FOR CONTROLLING CLEARANCE OF A READ ELEMENT AND A WRITE ELEMENT IN THE DISK DRIVE - A disk drive. The disk drive includes a disk, a head-slider, a moving mechanism, and a controller. The head-slider includes a read/write element, a first heater element, a contact pad, and a second heater element. The read/write element includes a read element configured to read user data from the disk, and a write element configured to write user data to the disk. The moving mechanism is configured to support and to move the head-slider. The controller is configured to control the second heater element to control contact between the contact pad and the disk, and is configured to control clearance between the read/write element and the disk by using the first heater element with the contact pad in contact with the disk. | 03-24-2011 |
20110102933 | DISK DRIVE AND METHOD FOR MEASURING CLEARANCE CHANGE IN THE DISK DRIVE - A method for measuring a change of a clearance between a head and a disk. The method includes reading a preliminarily written data string for clearance measurement on a disk to obtain a first measured value corresponding to a clearance, and writing a new data string for deterioration check onto the disk and reading the data string for deterioration check to obtain a second measured value corresponding to the clearance. The method also includes determining a deterioration of the data string for clearance measurement from a difference between the first measured value and the second measured value, measuring a clearance change using the data string for clearance measurement by a normal operation if the determination is that the data string for clearance measurement has not deteriorated, and measuring a clearance change by an operation different operation if the determination is that the data string for clearance measurement has deteriorated. | 05-05-2011 |
20110141603 | HEAD/DISK CONTACT DETERMINATION - A disk drive including a sensor element that senses contact between a head slider and a disk, a head integrated circuit (IC) comprising an amplification circuit section that amplifies a signal of the head slider, a controller IC comprising a controller that accesses a register of the head IC for controlling the head IC, and an identification section, within the head IC, that determines a contact frequency of the contact by the sensor element by using a timing control signal of the controller IC. | 06-16-2011 |
20120099218 | MAGNETIC-RECORDING HEAD WITH FIRST THERMAL FLY-HEIGHT CONTROL ELEMENT AND EMBEDDED CONTACT SENSOR ELEMENT CONFIGURABLE AS SECOND THERMAL FLY-HEIGHT CONTROL ELEMENT - A magnetic-recording head with a first thermal fly-height control (TFC) element and an embedded contact sensor element (ECSE) configurable as a second TFC element. The magnetic-recording head includes a write element, a read element, a first heater element, and an ECSE. The write element is configured for writing data to a magnetic-recording disk. The read element is configured for reading data from the magnetic-recording disk. The first heater element is configured as a first TFC element to coarsely adjust a fly-height of the magnetic-recording head with respect to the magnetic recording disk. The ECSE is configured to detect a contact with the magnetic-recording disk, and to function as a second heater element that is configured as a second TFC element to finely adjust the fly-height. The first heater element is configured with a first stroke-length larger than a second stroke-length of the second heater element for adjusting the fly-height. | 04-26-2012 |