Patent application number | Description | Published |
20080218896 | HEAD POSITION CONTROL DEVICE AND MEDIUM STORAGE DEVICE - A head position control device uses a current observer control which performs two degree of freedom control, with which a current step difference due to the difference of eccentricities between heads is prevented without affecting the seek waveform after switching heads. The head position control device has a locus generation section, which calculates an initial value of the correction locus for canceling the current step difference of the output current based on an output current supplied to an actuator before switching, and an eccentricity correction current and initial velocity of another head after switching; and a two degree of freedom control system to which a seek locus is input, and supplies a correction locus according to the initial value to the two degree of freedom control system. One parameter can correct the initial velocity and the current step difference. | 09-11-2008 |
20090279200 | STORAGE DEVICE, CONTROL CIRCUIT FOR STORAGE DEVICE, AND SERVO-WRITE-MODE IDENTIFYING METHOD - A servo-mark search control unit detects in a magnetic disk a servo mark matching a servo mark selected by a servo-mark candidate selecting unit. In this case, according to an instruction from a servo-mark search control unit, a non-volatile memory managing unit writes servo-write-mode identification information corresponding to the detected servo mark in a servo-write-mode identification-information storage unit of a non-volatile memory. In this manner, a magnetic disk device can recognize by itself a servo write mode with which servo patterns were written in a magnetic disk included in the magnetic disk device. | 11-12-2009 |
20090285073 | PATTERN TRANSFER APPARATUS AND PATTERN TRANSFER METHOD - A pattern transfer apparatus includes a storage-medium-surface detecting unit that detects a foreign substance or defect on a surface of a storage medium and specifies a position and a size of the foreign substance or defect; a relative-position adjusting unit that adjusts a relative position on a contact surface between the surface of the storage medium and a transfer pattern surface of a transfer master, and a relative-position-adjustment instructing unit that calculates an adjusted value of the relative position according to a detection result, and instructs the relative-position adjusting unit to adjust the relative position based on the adjusted value. | 11-19-2009 |
20100014184 | POSITION CONTROL APPARATUS AND DISK APPARATUS USING THE SAME - According to one embodiment, a position control apparatus includes: a digital control module that performs position control including disturbance adaptive control with a predetermined sampling period using a control constant, in accordance with a position error; and a table that stores the control constant corresponding to one of values sin(ωT), cos(ωT), and sin(ωT/2), wherein the digital control module determines a control value of the actuator in accordance with the position error, calculates a value of one of estimated errors of sin(ωT), cos(ωT), and sin(ωT/2) according to an adaptive law from a signal based on the position error, multiplies the calculated estimated error by an adaptive gain in accordance with a value of the angular frequency ω, updates one of the values, reads the corresponding control constant from the table based on the updated value, and updates the control constant. | 01-21-2010 |
20100014185 | POSITION CONTROL APPARATUS AND DISK APPARATUS USING THE SAME - According to one embodiment, a position control apparatus includes: a digital control module that performs position control including disturbance adaptive control with a predetermined sampling period using a control constant, in accordance with a position error between a target position and a current position of the object; and a table that stores the control constant corresponding to a value of sin(ωT) or cos(ωT), wherein the digital control module is configured to determine a control value of the actuator in accordance with the position error, calculates the value of sin(ωT) or cos(ωT) according to an adaptive law from a signal based on the position error, reads the corresponding control constant from the table in accordance with the calculated value of sin(ωT) or cos(ωT), and updates the control constant, to perform the position control including the disturbance adaptive control. | 01-21-2010 |
20100014186 | POSITION CONTROL APPARATUS AND DISK APPARATUS USING THE SAME - According to one embodiment, a position control apparatus includes: a digital control module that performs position control including disturbance adaptive control with a predetermined sampling period with the use of a control constant, in accordance with a position error between a target position and a current position of the object; and a table that stores the control constant corresponding to a value of sin(ωT/2), wherein the digital control module determines a control value of the actuator in accordance with the position error, calculates the value of sin(ωT/2) according to an adaptive law from a signal based on the position error, reads the corresponding control constant from the table in accordance with the calculated value of sin(ωT/2), and updates the control constant. | 01-21-2010 |
20100049946 | PROCESSOR, COMPUTER READABLE RECORDING MEDIUM, AND STORAGE DEVICE - A processor includes: a first storage part that stores instructions of a program including sets of instruction groups, which sets are hierarchically structured; a second storage part that stores an address value of the first storage part in which an instruction to be read next is stored; a third storage part that includes storage areas respectively corresponding to hierarchical levels of the program; and a control part that executes, when an instruction read from the first storage part is a call instruction that calls a different one of the sets of instruction groups, a control to store the address value in the second storage part in one of the storage areas of the third storage part that corresponds to one of the hierarchical levels with which the different one of the sets of instruction groups being executed is associated. | 02-25-2010 |
20100128385 | INFORMATION STORAGE DEVICE AND COMPUTER PRODUCT - According to one embodiment, an information storage device includes a recording/reproducing head, a positioning controller, a position detector, a storage module, and a position error detector. The position detector detects the position of the recording/reproducing head. The storage module stores servo control filters. The position error detector generates a new position error signal from a target position and the position of the recording/reproducing head when the positioning controller performs positioning control with control current obtained from a position error signal having passed through each servo control filter. Upon occurrence of a recording/reproducing error, learning to calculate a vibration amount from the position of the recording/reproducing head is sequentially performed for the servo control filters for a predetermined time. The positioning controller performs the positioning control with control current obtained from the position error signal having passed through one of the servo control filters where the vibration amount is smallest. | 05-27-2010 |