magnetic disk drive

Abstract

To provide a disk device which can reduce a generation rate of failures due to contamination.SOLUTION: A magnetic disk device includes: a rotatable magnetic disk; an actuator which supports and drives a head; a ramp for holding the head in an unloading position; a motor which rotates the magnetic disk; and a controller which performs loading operation to load the head from the ramp onto the magnetic disk and seek operation to move the head from the outer periphery of the magnetic disk to the side of the inner periphery after loading. When radial moving speed of the head during loading operation is set to be Vr1, circumferential moving speed of the head to be Vt1, radial moving speed of the head during seek operation to be Vrs, and circumferential moving speed to be Vts, the controller controls at least one of radial moving speed of the head and rotation speed of the magnetic disk so as to satisfy a relation of (Vr1 / Vt1)<(Vrs / Vts).SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a magnetic disk drive. [Background technology]

[0002] A hard disk drive (HDD), for example, is a magnetic disk device that has a rotatable magnetic disk and a magnetic head that writes and reads data to and from the magnetic disk. The magnetic head has a slider (head slider) and a head portion attached to the slider. When the HDD is in operation, the magnetic head faces the surface of the magnetic disk with a certain gap between them. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 6,243,222 [Patent Document 2] U.S. Patent No. 6,693,761 [Patent Document 3] U.S. Patent No. 7,561,367 Summary of the Invention [Problem to be solved by the invention]

[0004] One of the main causes of HDD failure is scratches on the magnetic head or magnetic disk when the magnetic head comes into contact with contaminants such as dust and dirt adhering to the media (hereinafter referred to as "contamination"). Although the inside of an HDD is kept highly clean, trace amounts of dust and dirt are present. Therefore, it is necessary to take measures to prevent damage even when the magnetic head comes into contact with contaminants. An object of the embodiments of the present invention is to provide a disk device that can reduce the incidence of failures due to contamination. [Means for solving the problem]

[0005] According to an embodiment, a disk drive includes a rotatable magnetic disk, an actuator that supports and drives a head that is movable radially of the magnetic disk, a ramp that holds the head at an unload position on the outer periphery of the magnetic disk, a motor that rotates the magnetic disk, a load operation that loads the head from the ramp onto the magnetic disk, and a seek operation that moves the head from the outer periphery to the inner periphery of the magnetic disk after loading. If the radial movement speed of the head during the load operation is Vr1, the circumferential movement speed of the head due to the rotation of the magnetic disk is Vt1, and the radial movement speed of the head during the seek operation is Vrs and the circumferential movement speed is Vts, then: a circumferential movement speed Vts of the head during the seek operation is set to a speed slower than a circumferential movement speed Vt1 of the head during the load operation; and a controller that controls at least one of the radial movement speed of the head and the rotation speed of the magnetic disk so as to satisfy the relationship (Vr1 / Vt1)<(Vrs / Vts). [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is an exploded perspective view of a hard disk drive (HDD) according to an embodiment. [Figure 2] FIG. 2 is a side view showing the magnetic head, suspension, and magnetic disk in the HDD. [Figure 3] FIG. 3 is a block diagram schematically illustrating the HDD. [Figure 4] FIG. 4 is a perspective view showing a lamp of the HDD. [Figure 5] FIG. 5 is an enlarged side view of a portion of the lamp. [Figure 6] Figure 6 shows the relationship between the disk rotation speed and the error rate in a HDD. [Figure 7] Figure 7 shows the relationship between the disk rotation speed and the incidence of scratches in HDDs. [Figure 8] FIG. 8 is a diagram that also clearly shows the relationship between the angle of a scratch on a recording medium and the occurrence of errors. [Figure 9]FIG. 9 is a graph showing the relationship between the disk rotation speed and the data loss rate according to the scratch width. [Figure 10] FIG. 10 is a diagram showing the relationship between the head seek speed and the data loss rate. [Figure 11] FIG. 11 is a diagram showing radial and circumferential velocities during a load operation and a seek operation. [Figure 12] FIG. 12 is a diagram showing the number of particles adhering to the medium surface before and after a seek. [Figure 13] FIG. 13 is a diagram showing the relationship between the disk rotation speed and the head flying height for the inner, middle, and outer periphery of the disk. DETAILED DESCRIPTION OF THE INVENTION

[0007] A magnetic disk drive according to an embodiment will be described below with reference to the drawings. The disclosure is merely an example, and appropriate modifications that are easily conceivable by those skilled in the art while maintaining the gist of the invention are naturally included within the scope of the present invention. Furthermore, in order to clarify the explanation, the drawings may show the width, thickness, shape, etc. of each part schematically compared to the actual embodiment, but these are merely examples and do not limit the interpretation of the present invention. Furthermore, in this specification and each drawing, elements similar to those described above with reference to the previous drawings may be designated by the same reference numerals, and detailed descriptions may be omitted or simplified as appropriate.

[0008] (Embodiment) A hard disk drive (HDD) according to an embodiment will be described in detail as a magnetic disk device. Fig. 1 is an exploded perspective view of the HDD according to an embodiment with the cover removed. As shown in FIG. 1, the HDD 11 includes a rectangular housing 10. The housing 10 has a rectangular box-shaped base 12 with an open top, and a cover (top cover) 14. The base 12 has a rectangular bottom wall 12a and side walls 12b extending along the periphery of the bottom wall, and is integrally molded from, for example, aluminum. The cover 14 is formed into a rectangular plate from, for example, stainless steel. The cover 14 is fastened to the side walls 12b of the base 12 with a plurality of screws 13, and hermetically closes the top opening of the base 12.

[0009] The housing 10 contains a plurality of magnetic disks 18 (e.g., ten) as disk-shaped recording media, and a spindle motor 19 that supports and rotates the magnetic disks 18. The spindle motor 19 is disposed on the bottom wall 12a. Each magnetic disk 18 has a disk-shaped substrate, e.g., 95 mm (3.5 inches) in diameter, and magnetic recording layers formed on the upper and lower surfaces of the substrate. The magnetic disks 18 are coaxially fitted to the hub of the spindle motor 19 and are further clamped by a clamp spring 20. This supports the magnetic disks 18 in a state parallel to the bottom wall 12a of the base 12. The spindle motor 19 rotates the magnetic disks 18 in the direction of arrow B at a predetermined rotation speed. The number of magnetic disks 18 mounted is not limited to ten, and may be nine or less, or ten to twelve or less.

[0010] The housing 10 contains a plurality of magnetic heads 17 that record and reproduce information on the magnetic disks 18, and an actuator assembly 22 that supports the magnetic heads 17 so that they can move freely relative to the magnetic disks 18. The housing 10 also contains a voice coil motor (VCM) 24 that rotates and positions the actuator assembly 22, a ramp load mechanism 25 that holds the magnetic heads 17 at an unload position separated from the magnetic disks 18 when the magnetic heads 17 move to the outermost periphery of the magnetic disks 18, and a board unit (FPC unit) 21 on which electronic components such as a conversion connector are mounted.

[0011] The actuator assembly 22 has an actuator block 29 supported rotatably around a support shaft 28, a plurality of arms 32 extending from the actuator block 29, and a suspension assembly 30 extending from each arm 32. The support shaft 28 is erected on the bottom wall 12a. A magnetic head 17 is supported at the tip of each suspension assembly 30. The actuator assembly 22 has a support frame (not shown) that extends from the actuator block 29 in the opposite direction to the arm 32, and this support frame supports a voice coil 34. The voice coil 34 is located between a pair of yokes 37 fixed on the base 12, and together with these yokes 37 and a magnet fixed to one of the yokes, the VCM 24 is configured.

[0012] The FPC unit 21 has a substantially rectangular base portion 21a fixed to the bottom wall 12a, a thin strip-shaped relay portion 21b extending from one side edge of the base portion 21a, and a joint portion 21c provided continuously with the tip of the relay portion 21b. The base portion 21a, the relay portion 21b, and the joint portion 21c are formed of a flexible printed circuit board (FPC). The joint portion 21c is attached to the actuator block 29. A printed circuit board 27 is screwed to the outer surface of the bottom wall 12a of the base 12. The base portion 21a of the FPC unit 21 is connected to the printed circuit board 27 via a connector (not shown). The printed circuit board 27 controls the operation of the spindle motor 19 and also constitutes a control unit (controller) that controls the operation of the VCM 24 and the magnetic head 17 via the board unit 21.

[0013] FIG. 2 is a side view showing the magnetic head and the magnetic disk in a floating state. As shown in the figure, magnetic disk 18 has a disk-shaped substrate 101 made of a non-magnetic material, such as glass. An underlayer 102, a magnetic recording layer 103, and a protective film 104 are sequentially laminated on each surface of substrate 101. Magnetic disk 18 is rotated in the direction of arrow B at a predetermined speed by a spindle motor 19. The suspension assembly 30 has a suspension 26, a wiring member (flexure) 28 attached to the suspension 26, and a tab 46 protruding from the tip of the suspension 26. The magnetic head 17 is supported by a gimbal portion 41 of the wiring member 40. The magnetic head 17 is electrically connected to the FPC unit 21 described above via the wiring member 40.

[0014] The magnetic head 17 is configured as a floating-type head and includes a slider 42 formed in a substantially rectangular parallelepiped shape and a head section 44 formed at the trailing end of the slider 42. The head section 44 includes a write head element and a read head element. The magnetic head 17 is maintained floating a predetermined distance above the surface of the magnetic disk 18 by airflow C generated between the disk surface and the slider 42 as the magnetic disk 18 rotates. The direction of the airflow C coincides with the rotational direction B of the magnetic disk 18. As the magnetic disk 18 rotates, the magnetic head 17 moves in the direction opposite to the rotational direction B (circumferential direction) relative to the magnetic disk 18.

[0015] Next, we will explain the ramp of the ramp load mechanism 25 and the positional relationship between the ramp and the suspension assembly. Fig. 3 is a perspective view showing the ramp of the ramp load mechanism, and Fig. 4 is a side view showing the engagement state between the tip of the suspension assembly and the ramp. The ramp load mechanism 25 includes a ramp 80. As shown in FIG. 1, the ramp 80 is fixed to the bottom wall 12a of the base 12 and is located near the periphery of the magnetic disk 18. When the HDD is not in operation, when the magnetic head 17 moves away from the outer periphery of the magnetic disk 18 and moves to a predetermined stopping position, the tab 46 of the suspension assembly 30 rides up onto the ramp 80. This keeps the magnetic head 17 in an unload position separated from the magnetic disk 18.

[0016] 3, the lamp 80 has a lamp body 82 formed in the shape of a rectangular plate, ten guide blocks 84 protruding from one surface of the lamp body 82, and a support bracket 85 protruding from the other surface of the lamp body 82, which are integrally molded from, for example, synthetic resin or metal. By fixing the support bracket 85 to the base 12, the lamp body 82 is arranged to stand almost perpendicular to the bottom wall 12a of the base. The guide blocks 84 have an elongated rectangular parallelepiped shape and extend substantially parallel to the bottom wall 12a. The ten guide blocks 84 are lined up at predetermined intervals in the axial direction of the magnetic disks 18. As shown in FIGS. 3 and 4, a rectangular recess (notch) 86 is formed in one end of each guide block 84 on the magnetic disk 18 side. When the ramp 80 is installed on the base 12, the outer peripheries of the ten magnetic disks 18 are positioned within the recesses 86 of the corresponding guide blocks with gaps between them.

[0017] Each guide block 84 has an upper guide surface (first guide surface) Ga that guides and supports the tab 46 of the down head suspension assembly 30, and a lower guide surface (second guide surface) Gb that guides and supports the tab 46 of the up head suspension assembly 30. The upper guide surface Ga and the lower guide surface Gb face each other and are disposed approximately perpendicular to one surface of the lamp body 82. The upper guide surfaces Ga and lower guide surfaces Gb of the ten guide blocks 84 are arranged to match the height of the corresponding suspension assemblies 30. Each guide surface Ga, Gb extends approximately along the radial direction of the magnetic disk 18 to near the outer periphery of the magnetic disk 18, and is arranged on the movement path of the tab 46.

[0018] The upper guide surface Ga extends from near the surface of the magnetic disk 18 (near the recess 86) in a direction away from the magnetic disk 18, in this case, in an upward inclined manner, and has a first inclined surface 87a for loading and unloading the magnetic head 17 onto the magnetic disk, a support surface 87b that extends subsequent to the first inclined surface 87a and approximately parallel to the magnetic disk surface, and a second inclined surface 87c that extends in an inclined manner from the other end of the support surface 87b to the end of the guide surface. Similarly, the lower guide surface Gb extends from near the surface of the magnetic disk 18 (near the recess 86) in a direction away from the magnetic disk 18, in this case, sloping downward, and has a first inclined surface 88a for loading and unloading the magnetic head 17 onto the magnetic disk, a support surface 88b that extends subsequent to the first inclined surface 88a and approximately parallel to the magnetic disk surface, and a second inclined surface 88c that extends slopingly from the other end of the support surface 88b to the end of the guide surface.

[0019] In the HDD 11, the VCM 24 rotates the actuator assembly 22 around the support shaft 28, so that the magnetic heads 17 are moved to desired seek positions while facing the surfaces of the magnetic disks 18. 4, when the HDD is not in operation, when the magnetic head 17 moves away from the outer periphery of the magnetic disk 18 and moves to a predetermined stopping position, the tabs 46 of the multiple suspension assemblies 30 climb onto the upper guide surface Ga and lower guide surface Gb of the corresponding ramp 80 and move to the predetermined stopping position. As a result, the magnetic head 17 is held in an unload position away from the magnetic disk 18. When the HDD 11 starts up, the VCM 24 rotates the actuator assembly 22 toward the magnetic disk 18, causing the tab 46 to slide on the upper guide surface Ga and the lower guide surface Gb toward the magnetic disk 18 and move from the inclined surfaces 87a and 88a onto the magnetic disk 18. This causes the magnetic head 17 to be loaded onto the magnetic disk 18.

[0020] FIG. 5 is a block diagram schematically illustrating an HDD according to the embodiment. As shown in the figure, the HDD 11 includes a head amplifier IC 91 that drives the magnetic head 17, a main controller 90, and driver ICs 92A and 92B. The head amplifier IC 91 is provided, for example, in an actuator block of the actuator assembly 22, and is electrically connected to the magnetic head 17. In this embodiment, the head amplifier IC 91 and the main controller 90 form a controller for the HDD 11. The main controller 90 and driver ICs 92A and 92B are configured, for example, on a printed circuit board 27 provided on the rear side of the housing 10.

[0021] The main controller 90 includes an R / W channel 94, a hard disk controller (HDC) 96, a microprocessor (MPU) 97, a motor controller 98A, a VCM controller 98B, and a memory 93. The main controller 90 is electrically connected to the magnetic head 17 via a head amplifier IC 91. The motor controller 98A is electrically connected to the spindle motor 19 via a driver IC 92A. The VCM controller 98B is electrically connected to the voice coil 34 of the VCM 24 via a driver IC 92B. The HDC 96 can be connected to a host computer 95.

[0022] Memory 93 stores data such as the magnetic head movement speed (radial speed) Vr1 and circumferential speed (equivalent to disk rotation speed) Vt1 during load operation at startup, the magnetic head radial speed (seek speed) Vrs and circumferential speed (equivalent to disk rotation speed) Vts during seek operation, and the magnetic head seek speed Vr and circumferential speed (disk rotation speed) Vt during normal operation (read and write operations). The MPU 97 and motor controller 98A of the main controller 90 control the rotation speed of the spindle motor 19 based on the data stored in the memory 93. The MPU 97 and VCM controller 98B control the radial movement speed (load speed and seek speed) of the magnetic head 17 based on the data stored in the memory 93.

[0023] Next, the loading and seeking operations of the magnetic head at the time of startup in the HDD 11 configured as above will be described. First, we will examine the cause of scratches on magnetic disks due to contamination present inside the housing. Figure 6 shows the relationship between disk rotation speed and error rate in HDDs, Figure 7 shows the relationship between disk rotation speed and scratch rate in HDDs, Figure 8 also shows the relationship between the angle of scratches on the recording medium and error occurrence, Figure 9 shows the relationship between disk rotation speed and data loss rate according to scratch width, and Figure 10 shows the relationship between head seek speed and data loss rate.

[0024] The probability of scratches (error rate) on the magnetic disk when the magnetic head comes into contact with contamination on the recording medium (magnetic disk) is greatly affected by the rotation speed of the magnetic disk. As shown in Figures 6 and 7, experimental results show that the higher the rotation speed of the magnetic disk, the higher the error rate (scratch rate) of the magnetic disk. This result is thought to be due to the fact that when the rotation speed of the magnetic disk is low, the speed at which the magnetic head crosses the medium surface during seek operations increases relatively, and the circumferential length of damage (scratches) that occurs on the medium when the contaminant comes into contact with the magnetic head is shorter than when the rotation speed is high.

[0025] As shown in Figure 8, when the rotation speed of the magnetic disk is low (the circumferential velocity Vt is low) and the seek speed of the magnetic head (the radial velocity Vr) is relatively high, scratches formed on the magnetic disk are high-angle scratches that are inclined at a large angle to the circumferential direction and the length of the scratches in the circumferential direction is short. In this case, the length of the drop in the read waveform within one sector is short, and the possibility of a read error is low. On the other hand, if the rotation speed of the magnetic disk is high (the circumferential velocity Vt is high) and the seek speed of the magnetic head (the radial velocity Vr) is relatively low, scratches formed on the magnetic disk will be low-angle scratches and will be long in the circumferential direction. In this case, the drop in the read waveform within one sector will be long, and there is a high possibility of a read error.

[0026] For example, in the case of the read channel of the HDD (4k sector drive) according to this embodiment, it is known that if data loss due to disk damage is less than 4.3%, read errors will not occur. In this HDD, the length of one sector is approximately 500 nm when the media radius position R is 40 mm and the seek speed is 0.1 m / s. If the width of a scratch on the media is 100 nm, the scratch length within one sector will be 23 μm at a rotation speed of 5400 rpm. In this case, as shown in Figure 9, the data loss rate falls within the readable range of less than 4.3%. In contrast, when the rotation speed of the magnetic disk is high, for example, 7200 rpm, the scratch length within one sector is 30 μm. In this case, the data loss rate is higher than 4.3%, and there is a high possibility of a read error.

[0027] As shown in Figure 9, reducing the disk rotation speed is more effective for scratches narrower than 100 μm in width, such as scratches 80 μm or 60 μm in width. If the data loss rate is 4.3% or less, even if scratches occur on the magnetic disk, it is possible to read the data, and the device will not fail.

[0028] Varying the seek speed of the magnetic head also changes the data loss rate within one sector. As shown in Figure 10, in an HDD, when the media radial position R is 40 mm and the magnetic disk rotation speed is 7200 rpm, increasing the seek speed reduces the data loss rate within one sector for scratch widths of 100 μm, 80 μm, and 60 μm. It can be seen that when the seek speed is increased from 0.1 m / s to 0.15 m / s, even scratches with a 100 μm width enter the readable range. It can also be seen that the narrower the scratch width, the greater the effect.

[0029] Based on the above verification results, the HDD of this embodiment aims to reduce the data loss rate by controlling the load speed (radial speed) and circumferential speed (equivalent to the disk rotation speed) during the load operation of the magnetic head, as well as the movement speed (seek speed) and circumferential speed (equivalent to the disk rotation speed) of the magnetic head during the seek operation of the magnetic head.

[0030] FIG. 11 is a diagram showing the radial movement speed (component) and the circumferential movement speed (component) of the magnetic head during a load operation and a seek operation. As shown in the figure, if the radial movement speed of the magnetic head 17 during the load operation is Vr1, the circumferential movement speed of the magnetic head due to the rotation of the magnetic disk 18 during the load operation (when the magnetic head is loaded onto the magnetic disk from the ramp 80) is Vt1, the radial movement speed (seek speed) of the magnetic head 17 moving from the outer periphery to the inner periphery of the magnetic disk during the seek operation after loading is Vrs, and the circumferential movement speed of the magnetic head relative to the magnetic disk is Vts, the main controller 90 The operation of the VCM 24 and / or the spindle motor 19 is controlled so as to satisfy the relationship (Vr1 / Vt1)<(Vrs / Vts).

[0031] For example, in a HDD with a magnetic disk rotation speed of 7200 rpm during normal operation (read and write operations), if Vr1 during load operations is set to 0.5 m / s and Vt1 is set to 30 m / s, then by setting Vrs during seek operations to 1 m / s and Vts to 23 m / s, This satisfies the relationship "(Vr1 / Vt1)≈0.02 < (Vrs / Vts)≈0.04." In one example, during a seek operation, the main controller 90 increases the radial movement speed of the magnetic head 17 from 0.5 m / s to 1 m / s and reduces the circumferential movement speed from 30 m / s to 23 m / s, for example, reducing the rotation speed of the magnetic disk 18 and spindle motor 19 from 7200 rpm to 5400 rpm. By controlling the radial and circumferential movement speeds of the magnetic head as described above, even if a scratch occurs on the magnetic disk due to contamination, it is possible to shorten the circumferential length of the scratch and keep the data loss rate low, which means that it is more likely to be possible to suppress signal linearity degradation problems when a scratch occurs.

[0032] According to this embodiment, when the HDD is started up, in the above-described seek operation, the magnetic head 17 seeks from the outermost to the innermost circumference of the magnetic disk 18 at least once, thereby executing a seek over the entire surface of the magnetic disk. FIG. 12 shows the number of particles adhering to the disk surface before and after a seek operation, and FIG. 13 shows the relationship between the disk rotation speed and the head flying height for the inner, middle, and outer periphery of the disk. 12, more than 90% of the contamination on the magnetic disk 18 is removed by a single full-surface seek by the magnetic head 17. During the full-surface seek operation, the seek speed Vrs and circumferential movement speed Vts of the magnetic head 17 are maintained at Vrs: 1 m / s and Vts: 23 m / s, respectively, as set forth above at startup. That is, the rotation speed of the magnetic disk 18 is set to 5400 rpm. After the above-described full-surface seek operation, in normal data processing operations (read operations, write operations), the main controller 90 returns the rotational speed of the magnetic disk 18 to, for example, 7200 rpm and executes the processing.

[0033] 13, it can be seen that the flying position (flying height) of the magnetic head does not change significantly even when the rotation speed of the magnetic disk is reduced from 7200 rpm to 5400 rpm. Therefore, even when a full-surface seek operation is performed at a low rotation speed of around 5400 rpm, the magnetic head 17 does not come into contact with the magnetic disk surface, and contamination can be removed without damaging the magnetic head 17 or the magnetic disk 18. However, the rotational speed of the magnetic disk cannot be set to an infinitely low value, and it is desirable to set the rotational speed taking into account the floating characteristics and variations of the magnetic head.

[0034] In the HDD according to the present embodiment, after the magnetic head loads onto the magnetic disk surface, the rotational speed of the magnetic disk is reduced, and then the magnetic head seeks from the outer periphery to the inner periphery of the magnetic disk. Alternatively, by increasing the seek speed of the magnetic head and seeking from the outer periphery to the inner periphery of the magnetic disk, contamination on the magnetic disk can be safely and efficiently removed. Furthermore, when the HDD is started, the relationship between the speeds of the load operation and the seek operation is set to (Vr1 / Vt1)<(Vrs / Vts), thereby increasing the traverse speed of the magnetic head relative to the media. Therefore, even if a scratch occurs on the magnetic disk due to contact between the contaminant and the magnetic head, the scratch is angled relative to the circumferential direction, thereby shortening the distance of signal degradation in the circumferential direction. This makes it possible to remove contamination from the magnetic disk while reducing the rate of data loss and the possibility of read errors. As described above, according to this embodiment, it is possible to obtain a disk device that can reduce the incidence of failures due to contamination.

[0035] In the above-described embodiment, the seek speed Vrs of the magnetic head is increased and the circumferential movement speed (disk rotation speed) Vts is decreased during the seek operation at startup, but this is not limiting and it is also possible to control only one of them. That is, by increasing the seek speed Vrs or decreasing the circumferential movement speed (disk rotation speed) Vts, it is possible to achieve the relationship (Vr1 / Vt1)<(Vrs / Vts).

[0036] The present invention is not limited to the above-described embodiments, and the components can be modified and embodied in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. For example, in a magnetic disk drive, the number of magnetic disks and the number of magnetic heads can be increased or decreased as needed, and various sizes of magnetic disks can be selected. The moving speeds Vr1, Vt1, Vrs, and Vts of the magnetic heads are not limited to those in the above-described embodiment, and can be adjusted to other speeds as appropriate. [Explanation of symbols]

[0037] 10... housing, 11... magnetic disk device, 17... magnetic head, 18... magnetic disk, 19...spindle motor, 22...actuator assembly, 24... Voice coil motor (VCM), 25... Ramp load mechanism, 80... Ramp, 90...Main controller, 98A...Motor controller, 98B...Motor controller

Claims

1. a rotatable magnetic disk; an actuator that supports and drives a head so as to be movable along the radial direction of the magnetic disk; a ramp for holding the head at an unload position on the outer periphery of the magnetic disk; a motor that rotates the magnetic disk; a load operation for loading the head from the ramp onto the magnetic disk, and a seek operation for moving the head from the outer periphery to the inner periphery of the magnetic disk after the loading; a controller that sets the radial movement speed of the head during the seek operation, Vts, to a speed slower than the circumferential movement speed Vt1 of the head during the load operation, where Vr1 is a radial movement speed of the head during the load operation, Vt1 is a circumferential movement speed of the head due to the rotation of the magnetic disk, Vrs is a radial movement speed of the head during the seek operation, and Vts is a circumferential movement speed of the head; and controls at least one of the radial movement speed of the head and the rotation speed of the magnetic disk so as to satisfy the relationship (Vr1 / Vt1)<(Vrs / Vts); A disk device comprising:

2. 2. The disk device according to claim 1, wherein the controller reduces the rotational speed of the motor to slow down the circumferential movement speed Vts.

3. 2. The disk device according to claim 1, wherein the controller sets a radial movement speed Vrs of the head during the seek operation to a speed faster than a radial movement speed Vr1 of the head during the load operation, and satisfies the relationship (Vr1 / Vt1)<(Vrs / Vts).

4. 2. The disk device according to claim 1, wherein the controller, during the seek operation, moves the head to seek over the entire area of ​​the magnetic disk from the outer periphery to the inner periphery while satisfying the relationship (Vr1 / Vt1)<(Vrs / Vts).

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