JPH1196708A - Head loading controller of disk memory device and head loading control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eventually embody the extremely low floating of a head and to attain a higher recording density by making it possible to suppress the occurrence of the contact and collision of a head and a disk with and against each other when a head loading action by a ramp loading system is carried out. SOLUTION: A disk 1 having the specific track recorded with data 20 for loading position detection for detecting the loading position of the head 2 on the prescribed circumference on the more outer peripheral side than a data region is used. A CPU executes the moving stop of the head or the suppression of the moving speed according to the detection of the data 20 for loading position detection when the head 2 moves onto the disk surface from a ramp device 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called ramp load type disk storage device which holds a head at a position not in contact with a disk surface and loads the head onto the disk surface during a seek operation.

[0002]

2. Description of the Related Art In recent years, in particular, in a small hard disk drive (HDD), various types of recording media (track density and linear density) for realizing a high recording density (track density and linear density) have been developed in order to increase the storage capacity. Technology is being developed. In order to increase the recording density, an ultra-low flying technique for minimizing the flying height of the head has been studied. The flying height of the head means a height (interval) between the disk surface and a head (actually, a read gap and a write gap) mounted on the slider when the slider is flying above the disk surface. .

By the way, in a conventional HDD, CSS (c
A head load method called an "ontact start and stop" method is generally used. In this head loading method, when the HDD is stopped, the head comes into contact with a CSS area arranged on the innermost side of the disk and stops, and when the disk rotates at a constant speed (high speed rotation), the head floats up from the CSS area. Load on data area. This C
In the SS system, when the head is stopped, the head is in contact with the disk surface. Therefore, if the disk surface has a so-called mirror surface having a high degree of smoothness, a suction phenomenon in which the head and the disk are suctioned occurs. For this reason, when the CSS method is adopted, fine irregularities called textures are provided at least in the CSS region. On the other hand, in order to increase the recording density as described above, it is desirable that the flying height of the head is lower. However, in the CSS method, the flying height of the head cannot be reduced below the height of the texture.
This is to prevent collision between the head and the texture).

Here, in addition to the CSS method, a head load method called a ramp load method (ramp-up / loading method) has been developed. In this ramp load method, as shown in FIG. 5, when the rotation of the disk 1 is stopped (when the HDD is stopped), the head 2 is moved to the vicinity of the outer periphery outside the data area of the disk 1 (or to the outside of the disk surface). ). In this case, the head 2 is held by the ramp device 3 in a non-contact state with the disk surface. Specifically, the ramp device 3 has a support having a slope (ramp surface) formed thereon, and supports the suspension 5 on which the head 2 is mounted. Suspension 5
Are components of the rotary actuator 6 constituting the head moving mechanism. The actuator 6 swings in the radial direction of the disk 1 by the voice coil motor (VCM) 7 to move the head 2 to the data area of the disk 1 (see FIG. 6).

Further, in the ramp load method, when the disk 1 is brought into a steady rotation state by the spindle motor 4, the head 2 is moved to the data area of the disk 1. That is, the head 2 is loaded on the disk surface so as to be guided by the ramp device 3. According to this ramp load method, the non-contact state between the head 2 and the disk 1 can be maintained, so that the disk surface can be made mirror-like and the flying height of the head can be reduced to the minimum.

[0006]

As described above, if the conventional ramp-load system is adopted, it is possible to make the flying height of the head as low as possible, and to increase the recording density of the disk. Becomes possible. However,
The conventional ramp load method has the following problems.

That is, during the head loading operation, the head 2 moves toward the disk 1 while the suspension 5 slides on the ramp surface (slope) of the ramp device 3. The slider that is the main body of the head 2 is flexibly supported by the suspension 5 via a gimbal. For this reason, vibration is generated by sliding with the ramp surface, and the posture of the slider becomes unstable. In particular, when the moving speed (entry speed) when the head 2 moves on the disk surface is high, there is a high possibility that the head 2 collides (contacts) with the disk surface due to the influence of the unstable attitude of the slider. Become. In particular, in the case of extremely low flying height, it is estimated that the frequency of contact or collision between the disk rotating at a high speed and the head becomes extremely high.

Accordingly, an object of the present invention is to make it possible to suppress the occurrence of contact or collision between a head and a disk when performing a head loading operation by a ramp loading method.
As a result, an extremely low flying height of the head is realized to achieve a high recording density.

[0009]

SUMMARY OF THE INVENTION The present invention relates to an HDD, for example.
A disk having a specific track on which a load position detection data for detecting a load position of a head is recorded on a predetermined circumference on an outer peripheral side of a data area. Further, the present apparatus includes a detection unit for detecting the load position detection data, and a control unit for suppressing the moving speed of the head.

The detecting means detects load position detecting data read by the head when the head moves from the stop position outside the data area to the disk surface by a head loading mechanism including a ramp device or the like. . When the control means inputs the detected load position detection data,
Suppress the moving speed of the head. Alternatively, the control means stops the movement of the head. The control means can recognize from the load position detection data that the head has moved to a position on the outer peripheral side on the disk. The control means temporarily stops the movement of the head or suppresses the moving speed, and then shifts to a normal seek operation for moving the head to the data area.

According to such a head loading method, when the head is guided by the head loading mechanism and moves on the disk surface, the movement of the head can be stopped or the moving speed can be suppressed. Therefore, even when the head (slider) attitude is unstable and the head rush speed in the disk direction is high, the head rush can be suppressed before the head is loaded into the data area. As a result, the possibility of contact or collision between the head and the disk during head loading can be reduced. For this reason, by utilizing the ramp load method, it is possible to realize an extremely low flying height in which the flying height of the head can be reduced to the minimum, and as a result, it is possible to achieve a high recording density.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual diagram for explaining a ramp load method related to the embodiment, FIG. 2 is a conceptual diagram for explaining operation of a ramp load method related to the embodiment, and FIG. FIG. 4 is a block diagram showing a main part of an HDD to which a ramp load method according to the embodiment is applied, and FIG. 4 is a flowchart for explaining a head loading operation of the embodiment. (Structure of HDD) This embodiment assumes an HDD to which a ramp load method is applied as a head load method. As shown in FIG. 3, the HDD has a spindle motor 4 for rotating the disk 1 as a recording medium, and a head moving mechanism (head driving means) for mounting the head 2 and moving the disk 2 in the radial direction of the disk 1. A head amplifier circuit 8, a read / write circuit 9 for executing various signal processing of a read signal read by the head 2 and a write signal for writing by the head 2, and a microprocessor (CPU) as a main control device of the HDD. ) 11, a motor driver 12, and a disk controller (HDC) 13.

The head moving mechanism includes a suspension 5 supporting the head 2 via a gimbal, a rotary actuator 6 for holding the suspension 5 and moving the head 2 in the radial direction of the disk 1, and a voice coil. It has a motor (VCM) 7. Here, the head 2 is placed on the slider by MR (magnetoresis).
5) A magnetic head having a structure in which a read head composed of a head and a write head composed of an inductive head (inductive type thin film head) are mounted separately from each other is assumed.

In this embodiment, the head moving mechanism and the ramp device 3 constitute a head loading mechanism. The ramp device 3 has a support on which a ramp surface (slope) is formed, and is arranged near the outermost peripheral side of the disk 1. When loading the head, the ramp device 3 has a function of guiding the head 2 onto the disk surface by causing the suspension 5 to slide on the ramp surface. In addition, the lamp device 3 has an HD
When D stops, the head 2 is held at a predetermined position (outside the data area of the disk 1) in a non-contact state with the disk surface. In the embodiment, as described later, the load position detection data 20 used for the head load operation is
It is recorded in advance on a specific track on the outer peripheral side of the disk 1.

The head amplifier circuit 8 amplifies a read signal read by the head 2 (read head) and outputs the amplified signal to a read / write circuit 9. The read signal includes the servo data and user data read from the data area, and the load position detection data 20 described above. The read / write circuit 9 has a servo circuit 10 for reproducing servo data together with a signal processing circuit for reproducing each data from a read signal. The servo circuit 10 reproduces servo data (which roughly includes a cylinder code and servo burst data) used for head positioning control and outputs the reproduced data to the CPU 11. The head positioning control is roughly divided into a seek operation for moving the head 2 to a target position (target track) in the data area and a position control operation (track following control operation) for setting the head 2 to the target position.

In this embodiment, the load position detection data 20 read by the head 2 is stored in the servo circuit 1.
It is assumed that the data is reproduced by 0 and supplied to the CPU 11. The CPU 11 controls the head loading operation based on the input load position detection data 20 as described later. The CPU 11 executes head load control related to the present embodiment together with the above-described head positioning control. The CPU 11 outputs a control amount (digital value) to the motor driver 12 at the time of head positioning control and head load control, and drives and controls the VCM 7.

The motor driver 12 has a D / A converter, converts a digital value from the CPU 11 into an analog signal (voltage value), and supplies a drive current for driving the VCM 7. The motor driver 12 includes an SPM driver for driving the spindle motor (SPM4) together with the VCM driver.

The HDC 13 forms an interface between the HDD and a host system (host computer), and mainly controls data transfer between the disk 1 and the host system. (Head Loading Operation) Hereinafter, the head loading operation of the ramp loading method of the embodiment will be described with reference to the flowcharts of FIGS.

In the ramp load method, when the HDD is stopped (when the rotation of the disk 1 is stopped), the head 2 is held with the suspension 5 supported on the ramp surface of the ramp device 3.
Are retracted outside the disk 1. That is, the head 2 is in a state of being stopped in a non-contact state with the disk surface.

Here, when the power of the HDD is turned on and the disk 1 is rotated by the spindle motor 4 and a seek operation for moving the head 2 to the data area of the disk 1 is started, the CPU 11 executes head load control.
First, the CPU 11 controls the motor driver 12 to
M7 is driven to swing the actuator 6 toward the disk 1 (step S1). With the drive of the actuator 6, as shown in FIG. 1, the suspension 5 moves toward the disk 1 while sliding on the ramp surface of the ramp device 3. Here, as shown in FIG. 2, the ramp surface is a slope having an inclination of, for example, 5 degrees with respect to the disk surface. The material of the ramp surface is desirably a hard plastic or the like that does not generate dust or the like even when the suspension 5 slides.

In the first embodiment, the CPU 11
The read operation by the (read head) is performed, and the read operation of the load position detection data 20 is performed (step S2). The load position detection data 20 is recorded in advance on a specific track arranged on the outer peripheral side outside the range of the data area of the disk 1. That is, when the head 2 moves to the disk 1 and reaches the position on the disk surface where the load position detection data 20 is recorded, the head 2 reads the load position detection data 20. The load position detection data 20 read by the head 2 is subjected to signal processing by the read / write circuit 9, and is reproduced by the servo circuit 10 and input to the CPU 11 in this embodiment.

The CPU 11 stores the load position detection data 20.
When the head 2 detects that the head 2 has read out in response to the input of the data, it recognizes that the head 2 has moved to the position of the specific track on the disk surface (YES in step S3).
At this time, as shown in FIG. 1, the suspension 5 is supported on the ramp surface of the ramp device 3, and before the head 2 enters the disk surface. The CPU 11 controls the driving of the VCM 7 to be temporarily stopped in response to the detection of the load position detection data 20 (step S4).

That is, the drive of the actuator 6 is stopped, and the head 2 is stopped on the disk surface. However, in practice, the CPU 11 performs control so as to temporarily suppress the moving speed of the head 2.

Then, the CPU 11 controls the driving of the VCM 7 again to control the actuator 6 to swing in the direction of the data area of the disk 1. That is, the CPU 11
Starts a seek operation to move the head 2 from the specific track position of the load position detection data 20 that has been temporarily stopped (the moving speed has been suppressed) to the target position in the data area.

According to such a head loading method, when the disk 1 rotates and the seek operation starts, the head 2
Is moved toward the data area of the disk 1 by the ramp device 3. At this time, when the head 2 moves to a specific position on the outer peripheral side on the disk surface, the head 2 temporarily stops.
Is stopped or the moving speed is suppressed. The specific position is a specific track position where the load position detection data 20 is recorded, as described above. In other words, the acceleration when the head 2 moves so as to rush from the ramp device 3 to the data area on the disk surface is controlled,
And the disk surface can be prevented from contacting or colliding with each other. The seek operation is started after the movement of the head 2 is temporarily stopped or the movement speed is suppressed, but the head 2 flies due to the air dynamic pressure due to the high-speed rotation of the disk 1. (Load Position Detection Data) The load position detection data 20 of the embodiment is recorded in advance at a predetermined position on the outer peripheral side of the disk 1 as described above. Here, the recording position of the load position detection data 20 will be described with reference to the conceptual diagram of FIG.

As shown in FIG. 2, assuming that the inclination angle of the ramp surface of the ramp device 3 is 5 degrees, the horizontal speed (load speed) of the head 2 at which the suspension 5 moves while sliding on the ramp surface. If the HV is set to "0.01 m / s", the speed VV at which the head 2 descends in the vertical direction is [VV = HV * tan5 = 0.87 (um / ms)].

Here, the spacing loss coefficient (head 2
Loss coefficient due to the distance from the disk surface) of 55 dB
In this case, the reproduction signal loss Ep of the head 2 has a relationship as shown in the following equation (1). Ep (dB) = − 55 * d / λ (1) where d is spacing (corresponding to the flying height FH), and λ is the data recording wavelength.

Normally, if there is a signal amplitude of about 1/4 of the reproduction output of the head 2, the read / write circuit 9 can normally execute the signal detection processing. Therefore, the recording position of the load position detection data 20 on the disk surface at which the output of the 1/4 reproduction signal (Ep = -12 dB) is obtained is set.

It is assumed that the signal wavelength of the load position detection data 20 is the same wavelength (λ = about 2 μm) as normal servo data. In this case, the following equations (2) and (3) are obtained from equation (1). −12 (dB) = − 55 * d / 2 (2) d = 0.44 (um) (3) From this equation (3), the flying height FH of the head 2 is 0.44.
(Um) or less. That is, as shown in FIG. 2, while the head 2 is being guided by the ramp device 3 and moving to slide down on the disk surface, the head 2 reads the load position detection data 20 and reads
In order to detect, the flying height FH of the head 2 is 0.44
(Um) or less. In other words, the recording position of the load position detection data 20 is set such that the flying height FH when the head 2 is guided by the ramp device 3 and falls on the disk surface is 0.44 (um) or less. Will do.

From the flying height of the head 2 of 0.44 (um), the flying height required for normal read operation is 0.04.
The time to descend to (um) is about 0.46 (ms). Within this time, the CPU 11 detects the load position detection data 20 in accordance with the read operation from the head 2, and
The movement of the head 2 is stopped or the movement speed is suppressed.

From the above description, it is desirable that the load position detection data 20 is actually the same data as the normal servo data, and that the data 20 is written to the specific position in the servo data writing process. However, since the load position detection data 20 is data for detecting the load position of the head 2 on the disk surface, the data content is not limited according to the principle of the present invention. Servo data is usually written on the disk 1 by a servo track writer (STW). In this STW, a clock head for writing a servo clock is used. However, the load position detection data 20 may be recorded using the clock head. That is, the load position detection data 20 may be the same data as the servo clock recorded in the servo area.

In the embodiment, in the HDD, a plurality of heads 2 are usually provided on the actuator 6 so as to face the disk surface. Therefore, the CPU 11
By switching a plurality of heads 2, the head 2 that has been read first
, The head load control for stopping the driving of the actuator 6 or suppressing the speed may be executed. Further, the mounting angle of the suspension 5 on which a certain head 2 is mounted is adjusted so that the head 2 always loads on the disk surface first, and the load position detection data 20 is transferred from the head 2 to the C.
You may make it input into PU11.

[0033]

As described above in detail, according to the present invention, it is possible to control the movement of the head outside the data area on the disk surface when performing the head loading operation by the ramp loading method. In addition, it is possible to suppress occurrence of a situation such as contact or collision between the head and the disk during loading. Therefore, as a result, it is possible to realize a very low flying height of the head and achieve a high recording density.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram for explaining a ramp load method according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram for explaining an operation of a ramp load method related to the embodiment.

FIG. 3 is an exemplary block diagram showing a main part of the HDD to which the ramp load method according to the embodiment is applied.

FIG. 4 is a flowchart for explaining a head loading operation of the embodiment.

FIG. 5 is a conceptual diagram for explaining a conventional ramp load method.

FIG. 6 is a conceptual diagram for explaining a conventional ramp load method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disk 2 ... Head (slider) 3 ... Ramp device 4 ... Spindle motor (SPM) 5 ... Suspension 6 ... Rotary actuator 7 ... VCM (voice coil motor) 8 ... Head amplifier circuit 9 ... Read / write circuit 10 ... Servo Circuit 11: Microprocessor (CPU) 12: Motor driver (VCM driver) 13: Disk controller (HDC)

Claims (12)

[Claims] 1. A disk storage having a head loading mechanism that holds a head at a stop position near the outer peripheral side of a disk and is not in contact with a disk surface and loads the head onto the disk surface from the stop position. A head load control device applied to a device, comprising: a disk having a specific track on which a load position detection data for detecting a load position of the head is recorded on a predetermined circumference on an outer peripheral side of a data area. Detecting means for controlling the head loading mechanism to move the head to the disk side and for detecting the load position detection data read by the head; and detecting the load position by the detection means. Control means for controlling the head loading mechanism to suppress the moving speed of the head when detecting the detection data; A head load control device comprising: 2. The control means controls the head loading mechanism to temporarily stop the head on a disk surface when the detection means detects the load position detection data. The head load control device according to claim 1. 3. The head loading mechanism has a ramp loading device for holding an actuator mounted with the head and guiding the actuator to a disk side, and the control means controls the actuator to be held by the ramp loading device. 2. The apparatus according to claim 1, wherein said head is temporarily stopped on a disk surface in a state in which the head is in a state of being operated.
The head load control device as described in the above. 4. The head according to claim 1, wherein the load position detection data is the same data as servo data recorded in advance on the disk and used for head positioning control. Load control device. 5. A head loading mechanism for holding the head at a stop position near the outer peripheral side of the disk and not in contact with the disk surface, and for loading the head onto the disk surface from the stop position. A disk storage device, comprising: a disk having a specific track on which a load position detection data for detecting a load position of the head is recorded on a predetermined circumference on an outer peripheral side of a data area; Head driving means for moving the disk in the radial direction, controlling the head driving means at the start of a seek operation,
Initial control means for moving the head held by the head loading mechanism toward the disk, detection means for detecting the load position detection data read by the head, and the load position by the detection means A disk storage device comprising: a seek control unit that starts a seek operation after controlling the head driving unit to temporarily suppress the moving speed of the head when detecting the detection data. . 6. The seek control unit controls the head driving unit to temporarily stop the head on a disk surface when the detection unit detects the load position detection data. The disk storage device according to claim 5, wherein 7. The disk has a plurality of disk surfaces, the head driving means has actuator means for integrally moving a plurality of heads arranged for each disk surface, and the detecting means has 6. The disk storage device according to claim 5, wherein the heads are sequentially switched to detect the load position detection data read by the head that first reaches the disk surface. 8. The data area of the disk is recorded in advance with servo data to be used for head positioning control including the seek operation, and the load position detection data is used to record the servo data. 6. The disk storage device according to claim 5, wherein the data is written to the specific track by the same means. 9. A head loading mechanism for holding the head at a stop position near the outer peripheral side of the disk and not in contact with the disk surface, and loading the head onto the disk surface from the stop position. A head load control method applied to a disk storage device, comprising: a disk having a specific track on which a load position detection data for detecting a load position of the head is recorded on a predetermined circumference on an outer peripheral side of a data area. At the start of a seek operation to move the head held by the head loading mechanism to the disk side, and to detect the load position detection data read by the head that has moved over the disk surface. And temporarily stopping the head on the disk surface when the load position detection data is detected. When, the head load control method characterized by comprising a process for seeking from the stopped state the head to the data area on the disk. 10. A method for writing servo data for use in head positioning control recorded in advance on the disk, wherein the head load mechanism is retracted from the disk storage device and the load position detection is performed. 2. The head load control device according to claim 1, wherein the data is written at a predetermined position on the disk by the same writing means as the servo data. 11. During the manufacturing process of the disk storage device before incorporating the head loading mechanism, the servo data and the load position detection data, which are recorded in advance on the disk and used for head positioning control, are stored in the disk storage device. 2. The head load control device according to claim 1, wherein writing is performed at a predetermined position on the disk, and after the writing, the head load mechanism is incorporated in the disk storage device. 12. A servo writer for writing servo data for use in head positioning control recorded on said disk in advance by a servo writer, wherein said load position detection data is written by a clock head provided in said servo writer. 2. The head load control device according to claim 1, wherein writing is performed at a predetermined position on the disk.