JP2008293557A - Disk drive device and retract method thereof - Google Patents

Abstract

The speed of an actuator is effectively controlled.
An HDD according to the present embodiment has a VCM brake function by short-circuiting a VCM coil. When the power is cut off during the seek operation toward the retracted position, the HDD 1 starts supplying the retract current to the VCM after performing the brake process. On the other hand, when the power is cut off during the seek operation in the direction opposite to the retracted position, the HDD 1 skips the brake process and starts supplying the retract current. As a result, the actuator can be prevented from colliding violently with the crash stop.
[Selection] Figure 4

Description

  The present invention relates to a disk drive device and a retract method thereof, and more particularly to control of brake processing in retract.

  As a disk drive device, a device using a disk of various modes such as an optical disk, a magneto-optical disk, or a flexible magnetic disk is known. Among them, a hard disk drive (HDD) is a computer storage device. As one of the storage devices indispensable in the present computer system, it is widely used. Furthermore, the use of HDDs such as a removable memory used in a moving image recording / reproducing apparatus, a car navigation system, a mobile phone, a digital camera, etc. is expanding more and more due to its excellent characteristics.

  The HDD includes a magnetic disk that stores data, a spindle motor that rotates the magnetic disk, a head slider that accesses the magnetic disk, and an actuator to which the head slider is fixed. The actuator is driven by a voice coil motor (VCM), and moves the head slider by swinging about a rotation axis. The head slider has a recording / reproducing thin film element (head element part) and a slider. The head slider flies over the magnetic disk with a certain gap.

  When the rotation of the magnetic disk stops, the head slider comes into contact with the surface of the magnetic disk, causing problems such as scratches on the data area and the inability to rotate the magnetic disk due to the adsorption phenomenon. -Save the slider from the data area. As described above, the CSS method and the ramp-load method are known as typical low methods for causing the magnetic head to enter the data area of the disk and to retreat from the data area.

  The ramp load method uses a ramp in the vicinity of the magnetic disk to retract the head slider. As the actuator rotates in the direction of the ramp and rests on the ramp, the head slider is unloaded. In unloading, the actuator climbs the ramp slope while sliding on the ramp surface in the unloading direction, and reaches a flat parking surface. Further, during loading, the actuator held on the parking surface descends while sliding in the loading direction on the inclined surface, moves away from the ramp, and moves over the disk surface. The CSS (Contact Start and Stop) method does not use a ramp and has a retreat position in the innermost peripheral area on the magnetic disk. Others are almost the same as the ramp load system.

  When the head slider is over the rotating magnetic disk, the HDD power supply may stop. When the rotation of the magnetic disk stops, the magnetic head comes into contact with the magnetic disk, causing a failure of the magnetic disk or the head element unit. Therefore, when the power supply is cut off, the head slider is retracted to the retracted position by the retract process. When the power is in the ON state, the actuator is controlled by the control of the VCM driver. When the power supply is in the stopped state, the head slider (actuator) is retracted to the retracted position by the retract driver.

  A typical retract driver retracts the actuator by rectifying the back electromotive force of the spindle motor and supplying a rectified current to the VCM coil. In addition, there is a method for driving the VCM using the voltage stored in the capacitor. While the VCM is driven by the retract current and the magnetic disk 11 is rotating, the actuator rotates toward the retracted position. The HDD includes an inner crash stop and an outer crash stop for defining the rotation range of the actuator on each of the inner circumference side and the outer circumference side of the magnetic disk. The retracted actuator collides with the outer crash stop (ramp load method) or the inner crash stop (CSS method) and stops.

  In the retract, if the momentum of the collision to the crash stop of the actuator is too strong, the head slider may return to the data area of the magnetic disk, and the magnetic disk or head element portion may be damaged. Alternatively, it is conceivable that the head slider largely vibrates in the vertical direction due to the collision between the actuator and the crash stop, and strongly collides with the magnetic disk or other members. Therefore, Patent Document 1 proposes a technique for controlling the retract speed.

In this technique, the power supplied to the actuator drive circuit when power supply is stopped is divided into three stages and supplied with a time difference. Electric power for stopping the actuator is supplied at the first time. The actuator starts retracting at a sufficiently low speed with the second small electric power, and reaches the vicinity of the ramp. After that, there is a third power supply and the vehicle accelerates and reliably retracts to a predetermined retract position. At this time, since the collision speed with the lamp can be set sufficiently low, damage to the lamp can be reduced.
JP-A-11-297014

  Patent Document 1 discloses a brake process by short-circuiting a VCM coil as a technique for controlling the VCM in the retract. When the short-circuited VCM coil rotates in the magnetic field, a back electromotive voltage is generated in the VCM. As a result, a driving force in a direction opposite to the rotation direction of the actuator is generated by the VCM. After the VCM is stopped by the brake process, the retract process by the retract current is started. By reducing the VCM speed by the brake process, it is possible to control more accurately than the subsequent VCM.

  However, using this braking process regardless of the operating state may produce undesirable results. Specifically, when the actuator is seeking in the retracted position direction, the collision speed between the actuator and the ramp or the crash stop due to the subsequent retract can be reduced by decelerating by the brake process. However, when the actuator is moving in the direction opposite to the retracted position, the VCM coil braking process cannot obtain sufficient deceleration, and the actuator may collide strongly with the crash stop.

  Alternatively, in the ramp load type load or unload process, if the actuator starts to ride on the ramp but the head slider is still on the magnetic disk and the VCM brake function is activated, the actuator stops on the ramp, The head slider may vibrate greatly up and down. This vibration may cause strong contact between the head slider and the magnetic disk and damage the magnetic disk or head element.

  One aspect of the present invention is a method of retracting a head to a retracted position when the power is turned off in a disk drive apparatus that moves the head by a moving mechanism having a voice coil motor. In this method, in the retract when the power is turned off during the seek operation in the direction of the retracted position, the speed in the direction of the retracted position is reduced by performing a brake process by short-circuiting the voice coil, A retract current is supplied in the direction of the retracted position. In the retraction when the power is turned off during the seek operation in the direction opposite to the retreat position, the retraction current in the retreat position direction is supplied by omitting the brake process. Thus, the effective speed control of an actuator can be performed by determining the presence or absence of a brake process according to a seek direction.

  In a preferred example, when the power is turned off during following, the brake processing in the retract to the retracted position is executed or omitted according to the seek direction immediately before the following position. Thus, effective speed control can be performed with simple control.

  In a preferred example, when the power is turned off during following, the braking process is omitted and a retract current toward the retracted position is supplied. As a result, the actuator can be retracted to the retracted position at an earlier timing.

  In a preferred example, when the head is in the retracted position, the moving mechanism is on a ramp, and when the moving mechanism is moved on the ramp toward the retracted position or the disk and is powered off in the meantime. In at least one of the retracts, the brake process is omitted and a retract current in the direction of the retracted position is supplied. As a result, the actuator stops when it is on the ramp, and the possibility of contact between the head and the disk can be reduced.

  In a preferred example, the function of the brake processing is disabled while the moving mechanism moves from the ramp to the disk, and is determined according to the servo data on the disk after moving on the disk. Whether to enable or disable the brake processing function is determined according to the seek direction. Thus, effective speed control can be quickly performed after the head moves on the disk.

  According to another aspect of the present invention, a head that accesses a disk, a moving mechanism that holds and moves the head, and a voice coil motor of the moving mechanism is controlled to control the movement of the moving mechanism. A disk drive device having a moving mechanism driver. The moving mechanism driver reduces the speed in the direction of the retracted position by performing a braking process due to a short circuit of the voice coil in the retract when the power is turned off during the seek operation in the direction of the retracted position. The retract current toward the retracted position is supplied to the voice coil. Further, in the retract when the power is turned off during the seek operation in the direction opposite to the retracted position, the brake processing is omitted and the retract current in the retracted position direction is supplied to the voice coil. Thus, the effective speed control of an actuator can be performed by determining the presence or absence of a brake process according to a seek direction.

  In a preferred example, when the moving mechanism driver is powered off during following, the braking process in the retract to the retracted position is executed or omitted according to the seek direction immediately before the following position. . Thus, effective speed control can be performed with simple control.

  In a preferred example, when the moving mechanism driver is powered off during following, the moving mechanism driver omits the braking process and supplies a retract current toward the retracted position. As a result, the actuator can be retracted to the retracted position at an earlier timing.

  In a preferred example, the moving mechanism is on a ramp when the head is in the retracted position, and the brake function is disabled while the moving mechanism is on the ramp. As a result, the actuator stops when it is on the ramp, and the possibility of contact between the head and the disk can be reduced. Furthermore, in a preferred example, after the moving mechanism moves from the ramp to the disk, the brake function is enabled / disabled according to the seek direction determined according to the servo data on the disk. Is done. Thus, effective speed control can be quickly performed after the head moves on the disk.

  Another aspect of the present invention includes a head that accesses a disk, a moving mechanism that holds and moves the head, a ramp that retracts in response to power-off, and a voice of the moving mechanism. A disk drive device having a moving mechanism driver that controls the movement of the moving mechanism by controlling a coil motor. The moving mechanism driver has a brake processing function by a short circuit of a voice coil. The brake function is in a disabled state when retracted when the moving mechanism is powered off while moving on the ramp. As a result, the actuator stops when it is on the ramp, and the possibility of contact between the head and the disk can be reduced.

  In a preferred example, the brake function is disabled before the head begins to unload from the disk toward the ramp. This can reduce the possibility of contact between the head and the disk due to the timing at which the actuator comes into contact with the ramp or the stop on the ramp by simple control.

  In a preferred example, after the moving mechanism moves from the ramp to the disk, the brake function is enabled / disabled according to the seek direction determined according to the servo data on the disk. . Thus, effective speed control can be quickly performed after the head moves on the disk.

  Another aspect of the present invention is a method of retracting the moving mechanism to a retracted position on a ramp when the power is turned off in a disk drive apparatus that moves the head by a moving mechanism having a voice coil motor. . This method uses a brake process by a short circuit of a voice coil before supplying a retract current in the direction of the retracted position when retracting from the disk to the retracted position. At least one of the retracts when the moving mechanism moves on the ramp toward the retracted position or the disk and is powered off, the brake process is omitted and the retract current toward the retracted position is omitted. Supply. As a result, the actuator stops when it is on the ramp, and the possibility of contact between the head and the disk can be reduced.

  In a preferred example, when the moving mechanism is powered off during unloading while moving from the disk toward the ramp, the brake process is omitted and a retract current is supplied in the direction of the retracted position. To do. This can reduce the possibility of contact between the head and the disk due to the timing at which the actuator comes into contact with the ramp or the stop on the ramp by simple control.

  In a preferred example, the function of the brake processing is in a disabled state while the moving mechanism moves from the ramp to the disk, and is determined according to the servo data on the disk after moving to the disk. The brake processing function is enabled / disabled in accordance with the seek direction. Thus, effective speed control can be quickly performed after the head moves on the disk.

  According to the present invention, the speed of the actuator can be effectively controlled.

  Hereinafter, preferred embodiments to which the present invention is applied will be described. For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. Moreover, in each drawing, the same code | symbol is attached | subjected to the same element and the duplication description is abbreviate | omitted as needed. In the following, embodiments of the present invention will be described by taking a hard disk drive (HDD) as an example of a disk drive device as an example. The HDD according to the present embodiment realizes appropriate speed control by selecting the use of the brake process by short-circuiting the VCM coil in accordance with the operation state during the movement of the actuator. First, the overall configuration of the HDD will be described.

  FIG. 1 is a plan view schematically showing the structure of the HDD 1 with the top cover removed. Each component of the HDD 1 is accommodated in the base 102. The HDD 1 has a magnetic disk 101 that is a disk for storing data. A head slider 105, which is an example of a head, includes a head element unit that writes and / or reads data input / output to / from an external host (not shown), and the head element unit. And a slider formed on the surface.

  The actuator 106 holds the head slider 105 and moves it. The actuator 106 rotates about a rotation shaft 107 and is driven by a voice coil motor (VCM) 109 as a drive mechanism. The assembly of the actuator 106 and the VCM 109 is a moving mechanism of the head slider 105. The actuator 106 includes constituent members coupled in order of the suspension 110, the arm 111, and the flat coil 112 from the front end in the longitudinal direction where the head slider 105 is disposed. The VCM 109 includes a flat coil 112 that is a VCM coil, a stator magnet (not shown), and the like.

  A spindle motor (SPM) 103 fixed to the base 102 rotates the magnetic disk 101 at a predetermined angular velocity. In order to access (read or write) the magnetic disk 101 by the head slider 105, the actuator 106 moves the head slider 105 over the data area of the rotating magnetic disk 101. The head slider 105 moves on the magnetic disk 101 by balancing the pressure due to the viscosity of the air between the slider's ABS (Air Bearing Surface) surface and the rotating magnetic disk 101 with the pressure applied by the suspension 110. Ascend with a gap.

  When the rotation of the magnetic disk 101 stops, the actuator 106 retracts the head slider 105 from the data area to the ramp 115. The ramp 115 is in the vicinity of the magnetic disk 101 at an outer position on the outer peripheral side of the magnetic disk 11. A part of the ramp 115 overlaps the recording surface of the magnetic disk 11, and the tab 117 at the tip of the actuator 106 slides on the ramp 115 and stops at a stop position on the ramp 115. This position is a retracted position of the actuator 106 and the head slider 105. The actuator 106 moves to the lamp 115 before the normal power-off, and also retracts to the lamp 115 during a sudden power-off during operation. The unload process in response to this sudden power-off is called a retract process. The retract process will be described in detail later.

  An inner crash stop 114 and an outer crash stop 113 for defining the rotation range of the actuator 106 on each of the inner circumference side and the outer circumference side of the magnetic disk 101 are attached to the base 102. The inner crush stop 114 serves to prevent the actuator 106 from contacting the top clamp 104. The outer crash stop 113 prevents the magnetic head 105 from passing through the ramp 115 during unloading. In the retracting process, the actuator 106 stops by colliding with the outer crash stop 113. Note that the present invention can be applied to a CSS (Contact Start and Stop) system in which the head slider 105 is retracted to an area disposed on the inner or outer periphery of the magnetic disk 101.

  FIG. 2 is a block diagram schematically showing the overall functional configuration of the HDD 1. On a circuit board 20 fixed outside the base 102, a read / write channel (RW channel) 21, a motor driver unit 22, a hard disk controller (HDC) and an MPU integrated circuit (HDC / MPU) 23 Each circuit such as the RAM 24 exists. The motor driver unit 22 drives the SPM 103 and the VCM 109 according to control data from the HDC / MPU 23. The motor driver unit 22 of this embodiment has a brake function of the VCM 109. The brake function generates a counter electromotive voltage by short-circuiting the flat coil 112 and decelerates the VCM 109. The use mode of the brake function will be described in detail later.

  An arm electronic circuit (AE: Arm Electronics) 13 fixed to the actuator 106 accesses (reads or writes) the magnetic disk 11 from the plurality of head element units 12 according to control data from the HDC / MPU 23. And amplify the read / write signal. The RW channel 21 extracts servo data and user data from the read signal acquired from the AE 13 and performs decoding processing. The decoded data is transferred to the HDC / MPU 23. In the write process, the RW channel 21 code-modulates the write data transferred from the HDC / MPU 23, converts the data into a write signal, and supplies the write signal to the AE 13.

  The HDC / MPU 23 transmits the read data from the magnetic disk 11 acquired from the RW channel 21 to the host 51. Write data from the host 51 is transferred to the RW channel 21 via the HDC / MPU 23. Read data and write data are temporarily stored in the buffer of the RAM 24. In the HDC / MPU 23, the HDC is a logic circuit, and the MPU operates according to the microcode loaded in the RAM 24. As the HDD 1 starts up, the RAM 24 is loaded with data necessary for control and data processing from the magnetic disk 11 or ROM (not shown), in addition to the microcode operating on the MPU.

  The HDC / MPU 23, which is an example of a controller, performs overall control of the HDD 1 in addition to necessary processing relating to data processing such as positioning control of the head slider 105, interface control, and defect management. In addition, the HDC / MPU 23 of the present embodiment controls enabling / disabling of the VCM brake function according to the operating state.

  Below, the usage method of the VCM brake function of this form is demonstrated. The VCM brake function generates a counter electromotive voltage by short-circuiting the flat coil 112 and generates a driving force in the direction opposite to the rotation direction of the VCM 109. Specifically, the VCM brake function generates a driving force toward the outer peripheral side (the lamp 115 side) when the actuator 106 is rotating toward the inner peripheral side (the spindle side of the SPM 103) of the magnetic disk 101. On the other hand, when the actuator 106 rotates to the outer peripheral side of the magnetic disk 101, a driving force to the inner peripheral side is generated. As a result, the actuator 106 (VCM 109) can be decelerated.

  In this embodiment, the VCM brake function is used in the retract process. If the power is suddenly turned off while the HDD 1 is operating, the actuator 106 is retracted to the retracted position. Specifically, the motor driver unit 22 unloads the actuator 106 to the stop position of the ramp 115 that is the retracted position. Since the power supply is in the OFF state, the motor driver unit 22 drives the VCM 109 using the counter electromotive force of the SPM 103 or the power stored in the capacitor. Note that the present invention may be used in a process different from the retract process.

  FIG. 3A schematically shows a change in the retract current in the retract process in which the VCM brake process is performed. If a sudden power-off occurs during operation, the flat coil 112 of the VCM 109 is short-circuited, and the actuator 106 is braked and decelerated. During this braking process, the motor driver unit 22 does not supply a retract current to the VCM 109. After the brake processing period, a first retract current supply period follows. The motor driver unit 22 supplies the first retract current to the VCM 109. The current direction of the first retract current is a direction in which the actuator 106 is driven toward the retracted position.

  The first retract current supply period is followed by the second retract current supply period. The second retract current is larger than the first retract current, and the current direction is the same. The first retract current moves the actuator to the ramp 115 and is reliably pressed against the outer crash stop 113 by the second retract current to maintain the stop position. Note that a constant retract current may be supplied instead of the multi-stage retract current.

  The HDD 1 of this embodiment turns on / off the VCM brake function according to the operating state. FIG. 3B schematically shows a change in the retract current in the retract process in which the VCM brake process is performed. The retract current after power-off is the same as the retract process for performing the VCM brake process in FIG. 3A except that the first brake process period is omitted. Specifically, the motor driver unit 22 starts supplying the retract current after performing the brake process when the power is cut off during the seek operation to the outer peripheral side. On the other hand, when the power interruption occurs during the seek operation to the inner circumference side, the motor driver unit 22 omits the brake process and starts to supply the retract current.

  When the power is shut off while the head slider 105 seeks to the outer periphery, the supply of the retract current accelerates the actuator 106. Therefore, there is a high possibility that the actuator 106 will collide with the ramp 115 or the outer crash stop 113 at a high speed. Therefore, the actuator speed can be effectively controlled by once decelerating the actuator 106 by the VCM brake and then supplying the retract current. The seek is a movement of the actuator 106 and the head slider 105 toward the target position (target track) on the magnetic disk 11.

  On the other hand, when the power is shut off while the head slider 105 seeks to the inner circumference side, it is necessary to avoid the actuator 106 from colliding with the inertia crash stop 114 violently. The deceleration effect of the actuator 106 is greater when the retract current is supplied than when the deceleration is performed by the VCM brake. Further, since the actuator 106 is rotated toward the inner peripheral side, the actuator 106 does not collide with the ramp 115 or the outer crash stop 113 violently even if the retract current is supplied immediately. For this reason, when the retraction process is started during the seek operation toward the inner circumference side, the motor driver unit 22 omits the brake process.

  Specifically, as shown in the flowchart of FIG. 4, when the power is cut off (S11), the motor driver unit 22 starts the retracting process (S12). When the seek direction is the retracted position direction (Y in S13), the motor driver unit 22 performs a braking process by short-circuiting the flat coil 112. When the seek direction is opposite to the retracted position direction (N in S13), the motor driver unit 22 omits the brake process. Thereafter, the motor driver unit 22 supplies a retract current to the VCM 109 (S15), the actuator 106 and the head slider 105 stop at the retracted position, and the retracting process ends (S16).

  FIG. 5 is a block diagram schematically showing a circuit configuration in the motor driver unit 22. The motor driver unit 22 includes a VCM driver 221 and a retract driver 222. The VCM driver 221 performs normal VCM control. That is, when the HDD 1 is in the ON state, the VCM 109 is controlled in each mode such as load / unload, seek, and following. The VCM driver 221 operates under the control of the HDC / MPU 23.

  The retract driver 222 performs a process of retracting the actuator 106 to the stop position when the power is turned off during the operation of the HDD 1. The retract driver 222 is operated by the back electromotive force of the SPM 203. The power supply voltage detection unit 401 detects the power supply state of the HDD 1. The register 403 stores setting data from the HDC / MPU 23. Setting data for enabling / disabling the VCM brake function is stored in the register 403. The counter 402 indicates each length of the brake processing period, the first retract current supply period, and the second retract current supply period. The HDC / MPU 23 can specify the length of each period.

  The control unit 404 executes each processing step according to the settings of the register 403 and the counter 402. The retract current adjusting unit 408 selects a first retract current and a second retract current. In this example, the first retract current is a current caused by the one-phase back electromotive force of the SPM 203, and the second retract current is a current caused by the three-phase back electromotive force of the SPM 203. The retract current adjustment unit 408 adjusts the retract current in accordance with an instruction from the control unit 404.

  In the brake processing period, the control unit 404 sets the first and second switches 405 and 406 to OFF, and sets the third switch 407 to ON. The flat coil 112 of the VCM 109 is in a short circuit state, and generates a counter electromotive force in a direction opposite to the rotation direction of the actuator 106. While supplying the retract current, the first and second switches 405 and 406 are ON, and the third switch is OFF. The current due to the counter electromotive force of the SPM 203 is supplied to the flat coil 112 via the retract current adjustment unit 408. Note that while the VCM driver 221 drives the VCM 109, the first to third switches are OFF.

  As described above, the HDC / MPU 23 sets enable / disable of the VCM brake function. In a preferred example, the HDC / MPU 23 sets the VCM brake function in the register 403 according to the seek direction before the seek operation is started. A specific setting method will be described with reference to the flowchart of FIG. When receiving a seek request from the host 51 (S21), the HDC / MPU 23 specifies a seek direction from the current track and the target track position (S22).

  When the seek direction is the retracted position direction, that is, the lamp 115 direction (Y in S23), the HDC / MPU 23 accesses the register 403 to enable the VCM brake function. When the seek direction is the direction opposite to the retracted position direction, that is, the spindle direction (N in S23), the HDC / MPU 23 accesses the register 403 and sets the VCM brake function to disabled. Thereafter, the HDC / MPU 23 controls the VCM driver 221 to start a seek operation (S26). When the head slider 105 arrives at the target track and seek is completed (S27), the HDC / MPU 23 controls the VCM driver 221 to perform following (S28).

  Next, a specific example of the retract process will be described with reference to the flowchart of FIG. When the power is cut off during operation (S31), the motor driver unit 22 starts the retraction process (S32). The control unit 404 refers to the register 403 to specify whether the VCM brake function is enabled or disabled. When enabled (Y in S33), the control unit 404 performs a brake process (S34). Specifically, the control unit 404 sets the third switch 407 to ON. The first and second switches 405 and 406 are kept OFF.

  When the counter 402 indicates that the predetermined period has elapsed, the control unit 404 starts to supply the retract current (S35). Specifically, the control unit 404 sets the third switch to OFF, and sets the first and second switches to ON. Further, the retract current adjustment unit 408 supplies the retract current to the flat coil 112 in accordance with an instruction from the control unit 404. When the VCM brake function is disabled (N in S33), the control unit 404 omits the brake process (S34). When the actuator 106 and the head slider 105 stop at the predetermined retracted position, the retracting process is completed (S36).

  In the above process, during the seek operation, the motor driver unit 22 executes or omits the brake process depending on the seek direction. On the other hand, when the seek is completed and the power is cut off during the following, the presence or absence of the brake process depends on the seek direction of the immediately preceding seek process. As can be understood from the description with reference to the flowcharts of FIGS. 6 and 7, the setting of the register 403 depends on the seek direction immediately before following. For this reason, the brake function is disabled when the previous seek to the following target track is directed toward the inner periphery, and is enabled when the seek is directed toward the outer periphery.

  Since the actuator 106 is stopped in principle in the following, the VCM brake function has a small possibility of head-disk contact regardless of whether it is enabled or disabled. As described above, the retract control can be made simpler by using the immediately preceding seek direction setting.

  After the seek is completed, the VCM brake function may be reset. After the seek is completed, the HDC / MPU 23 accesses the register 403 and sets the VCM break function. Since it is preferable to move the head slider 105 to the retracted position as soon as possible when the power is shut off, the HDC / MPU 23 preferably sets the VCM brake function to disabled in following.

  The above-described aspect is the retracting process when the actuator 106 is located away from the ramp 115, but the control of the VCM brake function when the actuator 106 is on the ramp 115 is also an important process. If the actuator 106 stops on the ramp 115 when the head slider 105 is on the magnetic disk 101 during loading or unloading, the head slider 105 largely vibrates in the vertical direction (in the direction of the rotating shaft 107), and the magnetic disk 101 may collide strongly. Therefore, it is important that the actuator 106 does not stop on the ramp 115.

  With reference to the flowchart of FIG. 8, processing in the case where a power interruption occurs during control unloading will be described. The HDC / MPU 23 starts a control unload process (S41). The control unload process is a controlled unload process when the power is on. The HDC / MPU 23 controls the VCM driver 221 to seek the head slider 105 to a predetermined specific track (S42). Thus, calibration for the unload operation to the lamp 115 is performed.

  When the seek to the specific track is completed, the HDC / MPU 23 accesses the register 403 and sets the VCM brake function to disabled (S43). The movement operation to the retreat position is started (S44). The control at this time adjusts the VCM current so that the back electromotive voltage of the VCM 109 approaches the reference value. When the power is cut off during the movement to the retreat position (S45), the retract driver 222 starts processing. The retract driver 222 supplies the retract current to the VCM 109 without performing the brake process (S46). The processing at this time is the same as that described with reference to FIG. When the actuator 106 stops at the stop position, the retracting process is completed (S47).

  By disabling the VCM brake function before the actuator 106 arrives at the ramp 115 during control unloading, the actuator 106 can be prevented from stopping on the ramp 115 due to braking. The timing for disabling the VCM brake is not limited to the above timing as long as it is before the lamp 115 of the actuator 106 contacts. However, preferably, as described above, until the end of the seek process before starting the movement to the retracted position, the VCM brake setting according to the seek direction is performed, and then the VCM brake function is disabled.

  In the load process from the ramp 115 to the magnetic disk 101, the VCM brake on the ramp 115 can be avoided by setting the VCM brake function to be disabled before starting the load process. The HDC / MPU 23 sets the VCM brake function before starting the first seek to the target track after the head slider 105 moves onto the magnetic disk 101 and reads the servo data. As a result, effective VCM control can be performed regardless of the power interruption at any timing.

  As mentioned above, although this invention was demonstrated taking the preferable embodiment as an example, this invention is not limited to said embodiment. A person skilled in the art can easily change, add, and convert each element of the above-described embodiment within the scope of the present invention. For example, the VCM brake process of this embodiment can be applied to a disk drive device that uses a disk other than a magnetic disk. If the power is turned off while the actuator is moving on the ramp, the brake function is preferably disabled on both roads and unloads, but it is also possible to disable only one of them. is there.

It is a figure which shows typically the whole structure of HDD which concerns on this embodiment. 1 is a block diagram schematically showing an overall circuit configuration of an HDD according to an embodiment. The retract current change in the retract processing concerning this embodiment is shown typically. It is a flowchart which shows the retract process according to the seek direction which concerns on this embodiment. It is a block diagram which shows typically the circuit structure in the motor driver unit which performs the retraction process which concerns on this embodiment. It is a flowchart which shows the setting process of the VCM brake function according to the seek direction which concerns on this embodiment. It is a flowchart which shows the retract process according to the seek direction which concerns on this embodiment. It is a flowchart which shows the retraction process at the time of control unloading concerning this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hard disk drive, 20 Circuit board, 21 RW channel 22 Motor driver unit, 23 HDC / MPU, 24 RAM
51 Host, 101 Magnetic disk, 102 Base, 103 Spindle motor 105 Head slider, 106 Actuator, 109 Voice coil motor 110 Suspension, 111 Arm 112 Flat coil 113 Outer crash stop, 114 Inner crash stop 117 Tab, 221 VCM driver, 222 retract driver 404 control unit, 403 register, 402 counter 405, 406, 407 first, second, third switch, 408 retract current adjustment unit

Claims (16)

In a disk drive device that moves a head by a moving mechanism having a voice coil motor, when the power is turned off, the head is retracted to a retracted position,
In the retract when the power is turned off during the seek operation in the retracted position direction, the speed in the retracted position direction is reduced by performing a brake process by short-circuiting the voice coil, and then in the retracted position direction. Supply the retract current of
A method of supplying a retract current in the direction of the retracted position by omitting the brake process in a retract when the power is turned off during a seek operation in the direction opposite to the retracted position.   The method according to claim 1, wherein when the power is turned off during the following, the braking process in the retract to the retracted position is executed or omitted depending on a seek direction immediately before the following position.   The method according to claim 1, wherein when the power is turned off during following, the braking process is omitted and a retract current toward the retracted position is supplied.   At least one of retracts when the moving mechanism is powered off while moving on the ramp toward the retracted position or the disk, the braking process is omitted and the retract current toward the retracted position is omitted. The method of claim 1, wherein: While the moving mechanism moves from the ramp to the disc, the function of the brake processing is in a disabled state,
The method according to claim 4, wherein after moving onto the disk, enabling / disabling of the function of the brake process is determined according to a seek direction determined according to servo data on the disk. A head to access the disk;
A moving mechanism for holding the head and moving the head;
A moving mechanism driver for controlling the movement of the moving mechanism by controlling a voice coil motor of the moving mechanism;
A disk drive device comprising:
The moving mechanism driver is:
In the retraction when the power is turned off during the seek operation in the direction of the retracted position, the speed in the direction of the retracted position is reduced by performing a brake process by short-circuiting the voice coil, and then in the direction of the retracted position. Is supplied to the voice coil,
A disk drive device that omits the braking process and supplies a retract current in the direction of the retracted position to the voice coil during retraction when the power is turned off during a seek operation in the direction opposite to the retracted position. .   The said movement mechanism driver performs or abbreviate | omits the said brake process in the retract to the said retracted position according to the seek direction immediately before the following position when it is powered off during following. The disk drive device described in 1.   7. The disk drive device according to claim 6, wherein when the moving mechanism driver is powered off during following, the brake processing is omitted and a retract current toward the retracted position is supplied. The disk drive device has a lamp;
7. The disk drive device according to claim 6, wherein the brake function is disabled while the moving mechanism is on the ramp.   The brake function is enabled / disabled according to a seek direction determined according to servo data on the disk after the moving mechanism moves from the ramp to the disk. The disk drive device described in 1. A head to access the disk;
A moving mechanism for holding the head and moving the head;
A ramp in which the moving mechanism retracts in response to power off;
A moving mechanism driver for controlling the movement of the moving mechanism by controlling a voice coil motor of the moving mechanism;
A disk drive device comprising:
The moving mechanism driver has a brake processing function due to a short circuit of the voice coil,
A disk drive device in which the brake function is in a disabled state when retracted when the moving mechanism is powered off while moving on the ramp.   12. The disk drive device according to claim 11, wherein the brake function is disabled before the head starts unloading from the disk toward the ramp.   The brake function is enabled / disabled according to a seek direction determined according to servo data on the disk after the moving mechanism moves from the ramp to the disk. The disk drive device described in 1. In a disk drive apparatus that moves a head by a moving mechanism having a voice coil motor, when the power is turned off, the moving mechanism is retracted to a retracted position on a ramp,
When retracting from the disk to the retracted position, use the brake process by shorting the voice coil before supplying the retract current toward the retracted position.
At least one of the retracts when the moving mechanism moves on the ramp toward the retracted position or the disk and is powered off, the brake process is omitted and the retract current toward the retracted position is omitted. Supply the way.   The retraction current in the direction of the retracted position is supplied when the power is turned off while the moving mechanism is moving from the disk toward the ramp during unloading. 14. The method according to 14. While the moving mechanism moves from the ramp to the disc, the function of the brake processing is in a disabled state,
The method according to claim 14, further comprising: determining whether to enable or disable the brake processing function according to a seek direction determined according to servo data on the disk after moving onto the disk.

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