Abstract: Approaches to a rotary actuator assembly configured for use in a hard disk drive (HDD) include a voice coil interleaved between the pivot bearing and the actuator arm, providing a longer pivot-to-head dimension which reduces the radius of curvature of the arc in which the head slider travels over the disk for accessing portions of the disk. Reducing the arc radius of curvature reduces the maximum skew angles of the read-write head in association with the disk tracks. The width of the actuator arm can be widened to provide improved operating characteristics even in view of the longer pivot-to-head dimension.

Abstract: Approaches to a rotary actuator assembly configured for use in a hard disk drive (HDD) include a voice coil interleaved between the pivot bearing and the actuator arm, providing a longer pivot-to-head dimension which reduces the radius of curvature of the arc in which the head slider travels over the disk for accessing portions of the disk. Reducing the arc radius of curvature reduces the maximum skew angles of the read-write head in association with the disk tracks. The width of the actuator arm can be widened to provide improved operating characteristics even in view of the longer pivot-to-head dimension.

Abstract: A hard-disk drive. The hard-disk drive includes a head-slider configured to fly in proximity with a recording surface of a magnetic-recording disk, and a fly-height variation compensator configured to generate a signal for compensating variation in fly height of a write element of the head-slider. The head-slider further includes the write element configured to write data to the magnetic-recording disk, a fly-height-adjustment heating element configured to displace the write element towards the magnetic-recording disk, and a position-adjustment heating element configured to displace the write element in at least a direction perpendicular to a flying direction. The fly-height variation compensator is further configured to add the signal for compensating variation in fly height to a control signal for output to the fly-height-adjustment heating element.

Abstract: In a positioning control system for a head of a magnetic disk device etc, a frequency of a disturbance oscillation having a specific oscillation component whose amplitude changes with a head position, is selected as a target frequency. Next, a resonance filter is so designed that it has a resonance characteristic at the target frequency and a variable gain device A having the gain changing with head position and a variable gain device B having inverse characteristics to the device A are connected to input and output terminals of the resonance filter, respectively. Input to the filter is made 0 during seek operation and an error signal is used as the input to the filter through the device A after the end of the seek operation. The variable gain devices A and B are controlled so that their product becomes 1.

Abstract: A track locus drawn on a disk discretely contains repeatable runout (RRO) components which are large in amplitude up to high-frequency band. In order to position a magnetic head along the track locus using filters good at suppressing RRO with resonance characteristics only at an integral multiple of a rotation frequency, many filters are required and thus it takes a long time for all the filters to go into a steady state. After learning until the filers go into a steady state, output values of the filters in a steady state are stored on a disk or in a memory. According to controlling the magnet head using these stored output values, the time required for the filters to go into a steady state becomes unnecessary.

Abstract: A disk drive. The disk drive includes a head, a moving mechanism, a first peak filter, an adaptive peak filter, and a filter controller. The head is configured to read servo data on a disk at sampling frequency. The moving mechanism is configured to move the head in proximity with a recording surface of the disk. The first peak filter has a fixed peak frequency and a variable gain, and is configured to be inserted into a servo loop. The servo loop is configured to position the head with position error signals between servo data read by the head and a target position. The adaptive peak filter has a variable peak frequency and a variable gain, and is configured to be inserted into the servo loop. The filter controller is configured to control the gain of the adaptive peak filter according to the gain of the first peak filter.

Abstract: A hard-disk drive. The hard-disk drive includes a head-slider configured to fly in proximity with a recording surface of a magnetic-recording disk, and a fly-height variation compensator configured to generate a signal for compensating variation in fly height of a write element of the head-slider. The head-slider further includes the write element configured to write data to the magnetic-recording disk, a fly-height-adjustment heating element configured to displace the write element towards the magnetic-recording disk, and a position-adjustment heating element configured to displace the write element in at least a direction perpendicular to a flying direction. The fly-height variation compensator is further configured to add the signal for compensating variation in fly height to a control signal for output to the fly-height-adjustment heating element.

Abstract: In a positioning control system for a head of a magnetic disk device etc, a frequency of a disturbance oscillation having a specific oscillation component whose amplitude changes with a head position, is selected as a target frequency. Next, a resonance filter is so designed that it has a resonance characteristic at the target frequency and a variable gain device A having the gain changing with head position and a variable gain device B having inverse characteristics to the device A are connected to input and output terminals of the resonance filter, respectively. Input to the filter is made 0 during seek operation and an error signal is used as the input to the filter through the device A after the end of the seek operation. The variable gain devices A and B are controlled so that their product becomes 1.

Abstract: Embodiments in accordance with the present invention relate to a positioning control system of a magnetic disk drive. Even if there is no phase correlation in a specific vibration component before and after a seek operation of a magnetic head, a resonance filter in accordance with an embodiment of the present invention follows the vibration at the frequency at high speed. A frequency showing a periodic disturbance is selected as a target frequency Ft[Hz]. A resonance filter showing a peak gain at a frequency Ft is designed. For an input to the resonance filter, a time-variable gain K(t) is used that varies depending on the time lapsed after the completion of a seek operation. This time-variable gain K(t) takes a value larger than 1 when the resonance filter starts operating, and after the lapse of a fixed length of time, the value becomes 1 by degrees.

Abstract: A carriage includes a slider on which a magnetic head for reading/writing information from/to a disk is mounted, a suspension for carrying the slider and for applying a predetermined load to the slider, a carriage arm to which the suspension is attached, and a body section to which the carriage arm is connected. The carriage arm includes a suspension fixing portion, as arm arranged substantially in parallel with a disk surface, and a restricting member which is a thin-plate-like member having a surface which is opposite to the plane of arm which is parallel to the disk surface. The restricting member and the arm are coupled via a viscoelastic body.

Abstract: In a magnetic disk device, oscillation occurring at a frequency higher than Nyquist frequency is suppressed. In one embodiment, a multi-late filter having a resonance point at a frequency higher than the intended Nyquist frequency is introduced in a previous stage of a controlled object. At that time, since a resonance characteristic of the multi-rate filter is aliased by a sampler, the multi-rate filter is designed such that the resonance point after the aliasing is stabilized in phase by a following compensator.

Abstract: In one embodiment, the magnetic disk drive has a magnetic head, an actuator driving the magnetic head, and a control portion controlling a controlled object, including the magnetic head and the actuator, by creating a control signal based on a given target position signal and on a position signal played back by the magnetic head such that the magnetic head reaches a target position.

Abstract: Embodiments in accordance with the present invention relate to a positioning control system of a magnetic disk drive. Even if there is no phase correlation in a specific vibration component before and after a seek operation of a magnetic head, a resonance filter in accordance with an embodiment of the present invention follows the vibration at the frequency at high speed. A frequency showing a periodic disturbance is selected as a target frequency Ft[Hz]. A resonance filter showing a peak gain at a frequency Ft is designed. For an input to the resonance filter, a time-variable gain K(t) is used that varies depending on the time lapsed after the completion of a seek operation. This time-variable gain K(t) takes a value larger than 1 when the resonance filter starts operating, and after the lapse of a fixed length of time, the value becomes 1 by degrees.

Abstract: A feedforward control system using a polynomial formula not affected by discretization error is realized in a magnetic disk drive. In one embodiment, the magnetic disk drive is intended to move a head for performing at least one of recording and playback to and from a magnetic recording medium to a target position. The feedforward input has a seek control system computed by a polynominal formula of a time function. The coefficients of the polynomial formula have been derived from boundary conditions including the characteristics of a zero-order hold.

Abstract: A carriage includes a slider on which a magnetic head for reading/writing information from/to a disk is mounted, a suspension for carrying the slider and for applying a predetermined load to the slider, a carriage arm to which the suspension is attached, and a body section to which the carriage arm is connected. The carriage arm includes a suspension fixing portion, as arm arranged substantially in parallel with a disk surface, and a restricting member which is a thin-plate-like member having a surface which is opposite to the plane of arm which is parallel to the disk surface. The restricting member and the arm are coupled via a viscoelastic body.

Abstract: In a magnetic disk device, oscillation occurring at a frequency higher than Nyquist frequency is suppressed. In one embodiment, a multi-late filter having a resonance point at a frequency higher than the intended Nyquist frequency is introduced in a previous stage of a controlled object. At that time, since a resonance characteristic of the multi-rate filter is aliased by a sampler, the multi-rate filter is designed such that the resonance point after the aliasing is stabilized in phase by a following compensator.

Abstract: A carriage for a magnetic disk apparatus includes a slider on which a magnetic head for reading/writing information from/to a disk is mounted, a suspension for carrying the slider and for applying a predetermined load to the slider, and a carriage arm to which the suspension is attached. The carriage arm includes a suspension fixing portion, first and second arms arranged substantially in parallel with a disk surface, and a restricting member having a surface opposite to the first and second arms. The restricting member and the first arm, and the restricting member and the second arm are coupled via a viscoelastic body.

Abstract: In one embodiment, the magnetic disk drive has a magnetic head, an actuator driving the magnetic head, and a control portion controlling a controlled object, including the magnetic head and the actuator, by creating a control signal based on a given target position signal and on a position signal played back by the magnetic head such that the magnetic head reaches a target position.

Abstract: A carriage for a magnetic disk apparatus includes a slider on which a magnetic head for reading/writing information from/to a disk is mounted, a suspension for carrying the slider and for applying a predetermined load to the slider, and a carriage arm to which the suspension is attached. The carriage arm includes a suspension fixing portion, first and second arms arranged substantially in parallel with a disk surface, and a restricting member having a surface opposite to the first and second arms. The restricting member and the first arm, and the restricting member and the second arm are coupled via a viscoelastic body.

Abstract: A carriage arm assembly for swingably supporting a magnetic head which includes a slider, a suspension carrying the slider, a carriage arm to which the suspension is attached, and a body section. The carriage arm extends from the body section and includes first and second arm members extending substantially in parallel with a swinging plane of the carriage arm, and a fixing portion provided at a distal end of the carriage arm for mounting the suspension thereon. Each of the first and second arm members have narrow sections in a distal end area and a base end area thereof, wherein a width of the narrow sections in a swinging direction is smaller than a width of an intermediate area of the first and second arm members.