Abstract: Method and apparatus are described for recovery from temporary errors in a disk drive resulting from excessive temperature or the like. After a first error recovery procedure has been executed and failed, a waiting time is selected after which a second error recovery procedure will be performed. The length of the waiting time can be determined by the measured temperature if a sensor is included in the drive. If the error still cannot be recovered after the waiting period, the location where the error had occurred is temporarily registered as defective. Subsequently the drive will retest the failing location and remove the temporary defect registration if the error has been removed by, for example, the temperature having gone down.

Abstract: The present invention provides a production process for a transparent heat-resistant resin, and further, a transparent heat-resistant resin and uses therefor, wherein the production process involves high dealcoholation conversion and a low content of residual volatiles in the resultant resin, and therefore can prevent foam or silver streak from occurring in the molded product, and further, facilitates melt-molding such as injection molding, and is fit for industrial production, and involves good efficiency.

Abstract: A method and system suitable for recording/reproducing audio-visual data on or from a hard disk or other storage media that can be accessed in random. Two streams, stream #1 and stream #2, are set. Then, 2000 sectors are set to the stream #1 and a specified number of sectors to the stream #2. By specifying this stream number (stream #1 or #2) and the audio-visual (AV) logical block address of the stream, the AV stream data recorded on the hard disk can be accessed. Each AV stream begins with zero and ends at the maximum AV stream LBA.

Abstract: The register disclosed herein includes a register block and a data writing block having non-volatile storage elements which store data output therefrom. The disclosed register further includes a data restoring block for reading data from the non-volatile storage elements. In a disclosed embodiment, the non-volatile storage elements are magnetic tunnel junction (MTJ) elements.

Abstract: A method and apparatus for recovering from operation errors arising in an information recording and reproducing unit using a head with a GMR sensor is described. The read and write operations of the unit comprise executing a first error recovery procedure for recovering the operation error, executing a first GMR evaluation procedure for evaluating the performance of the GMR sensor when the operation error cannot be recovered by the first error recovery procedure, and applying a resetting pulse to the GMR sensor in accordance with the first GMR evaluation procedure.

Abstract: A disk device, track positioning method, and method for generating a position error signal in which the occurrence of a wrong correction operation can be prevented by creating an appropriate PES without using a burst pattern having a defect, and reassign sectors can be decreased by decreasing defective sectors thereby to reduce the performance degradation is disclosed. In the disk device and track positioning method, the defect of a burst pattern read out from a disk is detected, and if a defect is detected in the burst pattern, a data value corresponding to the sum data of the burst pattern pair having the defect detected is obtained by measuring the maximum amplitude value of the burst pattern pairing with the burst pattern having the defect detected, and a PES is created according to the amplitude of the burst pattern having the defect detected and the maximum amplitude value.

Abstract: A magnetic random access memory (MRAM) circuit block and access method thereof are disclosed herein which includes a circuit for sensing a data write current passing through a bitline 32 and, for generating a stop signal for stopping a data write current supply to the bitline 32 and a write wordline 30 after data is written in an magnetic tunnel junction (MTJ) element 44. Further, when data to be written to the storage element is the same as the data already stored therein, no write current is supplied to the write wordline 30, thereby saving power.

Abstract: A method for controlling write current to a write head during data write on a hard disk drive is disclosed. A direct access storage device includes a rotating storage medium in which data are magnetically written, a write head for writing data in the rotating storage medium, and a write current control circuit for changing write current-value settings to be supplied to the write head according to a predetermined elapsed time from the beginning of a write operation.

Abstract: MRAM has read word lines WLR and write word line WLW extending in the y direction, write/read bit line BLW/R and write bit line BLW extending in the x direction, and the memory cells MC disposed at the points of the intersection of these lines. The memory MC includes sub-cells SC1 and SC2. The sub-cell SC1 includes magneto resistive elements MTJ1 and MTJ2 and a selection transistor Tr1, and the sub-cell SC2 includes magneto resistive elements MTJ3 and MTJ4 and a selection transistor Tr2. The magneto resistive elements MTJ1 and MTJ2 are connected in parallel, and the magneto resistive elements MTJ3 and MTJ4 are also connected in parallel. Further, the sub-cells SC1 and SC2 are connected in series between the write/read bit line BLW/R and the ground.

Abstract: A disk drive seek control system device to reduce track pitch. When data is recorded, an offset value is added to the position of a read head element along the width of a track corresponding to an offset &Dgr;w between the read head element and a write head element. The value of the offset depends on the yaw angle &thgr; of the head. When data is read, the position of the read head element is chosen to be either the position of the write head element during write operations, or the midpoint between the position of the write head element and the read head element during write operations, or the center of a track.

Abstract: A drive unit which recovers from write instability by heating the magnetic head prior to performing a dummy write operation is described. In the preferred embodiments, once write instability has been detected the head may be heated by friction with the rotating disk or by an external heater. In the friction method the head is moved to a safe area of the disk such as a textured landing zone while the disk rotation is continued. In drives using unload ramps, a heater is preferably placed at the the ramp so that the head can be heated while parked on the ramp. In each of these embodiments dummy write operations are performed while the head is in a thermally excited state due to the heating. The combination of heating and the dummy write operation aids in restoring write stability.

Abstract: The present invention provides: a photosensitive resin composition, which can form uniform coating films having higher coating film strength without causing surface contamination, decrease of evenness of coating films, decrease of film thickness, and coloring by decomposition in heat treatment of subsequent steps, and has good sensitivity of exposure. The photosensitive resin composition comprises a lactone-ring-containing polymer (A) as an essential component, wherein: the lactone-ring-containing polymer (A) is obtained by carrying out polymerization of comonomers and lactonization at the same time wherein the comonomers include a 2-(hydroxyalkyl)acrylate ester and an acidic-group-containing monomer; and the lactone-ring-containing polymer (A) is obtained by almost quantitatively carrying out lactonization of a 2-(hydroxyalkyl)acrylate ester structural unit.

Abstract: The signal output device of the present invention comprises of a driver circuit and a controller. The signal sending method of the present invention sets any one of a plurality of the different sending rates. The method also includes setting a slew rate of the driver circuit to a standard value that is in accordance with the predetermined data transfer rate, thereby starting signal transmission. The next step involves determining whether or not a data transfer error occurrence rate is below a predetermined allowable threshold. Then, changes in the slew rate of the driver circuit are made if the data transfer error occurrence rate is determined to be over the allowable threshold. Next, a search for a slew rate value that can decrease the data transfer error occurrence rate below the allowable threshold or decrease the data transfer error occurrence rate is performed. The new slew rate value is set as a new standard value.

Abstract: A disk drive seek control system device to reduce track pitch. When data is recorded, an offset value is added to the position of a read head element along the width of a track corresponding to an offset &Dgr;w between the read head element and a write head element. The value of the offset depends on the yaw angle &thgr; of the head. When data is read, the position of the read head element is chosen to be either the position of the write head element during write operations, or the midpoint between the position of the write head element and the read head element during write operations, or the center of a track.

Abstract: An Error Recover Procedure (ERP) is disclosed which, during execution of the ERP, while self-diagnosing the cause of error, dynamically changes the error recovery steps of the ERP. An appropriate ERP is selected and executed according to the detected error status.

Abstract: A disk device, track positioning method, and method for generating a position error signal in which the occurrence of a wrong correction operation can be prevented by creating an appropriate PES without using a burst pattern having a defect, and reassign sectors can be decreased by decreasing defective sectors thereby to reduce the performance degradation is disclosed. In the disk device and track positioning method, the defect of a burst pattern read out from a disk is detected, and if a defect is detected in the burst pattern, a data value corresponding to the sum data of the burst pattern pair having the defect detected is obtained by measuring the maximum amplitude value of the burst pattern pairing with the burst pattern having the defect detected, and a PES is created according to the amplitude of the burst pattern having the defect detected and the maximum amplitude value.

Abstract: The signal output device of the present invention comprises of a driver circuit and a controller. The signal sending method of the present invention sets any one of a plurality of the different sending rates. The method also includes setting a slew rate of the driver circuit to a standard value that is in accordance with the predetermined data transfer rate, thereby starting signal transmission. The next step involves determining whether or not a data transfer error occurrence rate is below a predetermined allowable threshold. Then, changes in the slew rate of the driver circuit are made if the data transfer error occurrence rate is determined to be over the allowable threshold. Next, a search for a slew rate value that can decrease the data transfer error occurrence rate below the allowable threshold or decrease the data transfer error occurrence rate is performed. The new slew rate value is set as a new standard value.

Abstract: A method and apparatus for reducing the amount of time from a power-on status to a ready status of a hard disk drive device. In response to a power-on of a disk drive device, the rotation of a data recording disk is started. The rotational speed of the data recording disk is increased. When it is detected that the rotational speed of the data recording disk reaches an intermediate rotational speed, which is lower than a final rotational speed of the data recording disk, the rotational speed of the data recording disk is fixed at the intermediate rotational speed. One or more control programs recorded on the data recording disk are read and then stored in a memory. Then a ready signal is sent to a host processor. The disk drive device may then receive a read command from the host processor to read data from the data recording disk and to transfer the data to the host processor is detected.

Abstract: A method and apparatus for minimizing performance degradation resulting from reassignment of data to alternate sectors as a result of a defect within the original sector.

Abstract: Methods and apparatus are described for a data transfer unit between a storage unit and a host, wherein a slower data transfer rate is established when a predetermined error is detected. In one embodiment the cyclicity of the error occurrence calculated and a wait is inserted between data to avoid transferring data at the calculated cyclicity point of the detected error. Optionally the data transfer unit may return the data transfer rate to the original data transfer rate or state after a predetermined time has elapsed, after a predetermined number of commands have been received, after a predetermined amount of data have been transferred, or by combination of these.