JPH0991911A - Carriage control device of disc-recording/reproducing apparatus and head-floating control method applied to disc-recording/reproducing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high recording density by eliminating a contact state of a head and a disc when the disc stands still with the utilization of a lamp load method, and restrict an occurrence frequency of contacts and collisions of the head and the disc even when the floating amount of the head is reduced at the driving time of the disc, thereby eventually allowing the head to float considerably low. SOLUTION: A lamp load-type HDD has a floating amount control device. When a disc 1 rotates normally, a head 2 is moved over the disc 1 and then the floating amount of the head 2 is controlled and decreased to send the head 2 close to the disc 1 by the control device. The control device is provided with a voltage control device 12 which applies a potential difference between the head 1 and disc 2 by an electrostatic attraction method thereby to exert a coulomb force. A microcontroller 10 detects that the head 2 is moved over a data area of the disc 1 by checking a reading operation of servo data, and then executes to reduce the floating amount of the head 2 greatly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ramp-load type disc recording / reproducing apparatus.

[0002]

2. Description of the Related Art In recent years, particularly in a small-sized hard disk drive (HDD), various kinds of recording density (track density and linear density) of a disk have been increased in order to increase the storage capacity. Is being developed.

As a technique for increasing the recording density, there is an extremely low flying technique for reducing the flying height of the head (actually, the slider). A conventional HDD is a CSS (contact).
The start and stop method is adopted, and when the disc is stationary, the head comes into contact with the CSS area of the disc and stops, and when the disc rotates normally (high-speed rotation), it floats and records and reproduces data on the data area. To do.

In this CSS system, the head is in contact with the disk surface when the disk is stopped. Therefore, if the surface of the disk is a mirror surface having high smoothness, the contact area between the head and the disk increases. As a result, an adsorption phenomenon occurs. When the adsorption phenomenon occurs, even if the HDD is activated, the spindle motor is not driven and the data recording / reproducing operation becomes impossible.

In order to prevent such an adsorption phenomenon, fine irregularities called texture are formed on the surface of the disc. On the other hand, in order to increase the recording density as described above, it is desirable that the flying height of the head be low. In other words, it is desirable that the distance between the head and the disk be minimized in the non-contact state. In the contact state, the disk rotates at a high speed, which causes a problem of wear and damage of the disk and the head.

However, due to the presence of the above texture,
The flying height of the head (also called the flying height) cannot be lower than the height of the texture. Therefore, when the conventional CSS method is adopted, there is a limit to the ultra-low flying technology.

Therefore, the ramp load method (ramp-up loading method) is attracting attention as opposed to the CSS method. The ramp load method is used when the disc is stationary.
This is a system in which the head is supported by a support at a position where it does not come into contact with the disk (outer peripheral side of the disk), and the head is moved onto the disk during steady rotation of the disk.

According to this ramp load system, the head and the disk are not in contact with each other and the disk surface can be mirror-finished, so that the flying height of the head can be reduced to the maximum.

[0009]

As described above, by adopting the conventional ramp load method, it is possible to achieve a very low flying height that lowers the flying height of the head to the limit, and to increase the recording density of the disk. it can. However, in the ramp load method, the head is normally retracted to the outside of the disk when the disk is stationary, and is moved onto the disk when starting. Therefore, it can be estimated that when the head is moved over the disk in the low flying state, the frequency of contact and collision with the disk rotating at high speed becomes very high. If the frequency of such contact or collision increases,
Heads and disks are likely to be damaged by impact.
Therefore, in actuality, simply using the conventional ramp load method cannot realize a low flying height that reduces the flying height of the head.

An object of the present invention is to eliminate the contact state between the head and the disk when the disk is at rest by utilizing the ramp load method, and even when the flying height of the head is lowered when the disk is started, The frequency of contact and collision of the head is suppressed, resulting in the extremely low flying height of the head,
The purpose is to increase the recording density.

[0011]

According to the present invention, in a carriage control device of a ramp-load type disc recording / reproducing apparatus, the head (actually a slider) is moved over the disc during steady rotation of the disc, and then the head is floated. This is a device having a flying height control means for controlling the amount of the flying air so as to lower it toward the disk.

As a concrete example, the flying height control means adopts an electrostatic suction method, and a Coulomb force is applied by applying a potential difference between the head and the disk. By this Coulomb force, the head and the disk are attracted, and the flying height of the head with respect to the disk is reduced to the maximum.

At this time, in order to reduce the flying height of the head, it is necessary for the head to move surely above the data area of the disk. Therefore, the flying height control means of the present invention detects the movement of the head over the data area of the disk, and then executes the control for reducing the flying height of the head to the limit by the action of the Coulomb force. This detection method detects that the head has moved onto the data area of the disk by confirming that the head has read the servo data from the disk.

With such a structure, by utilizing the ramp load method, the surface of the disk can be made to be a mirror surface, so that the flying height of the head can be reduced. Furthermore, at the time of starting the rotation of the disk, after moving the head onto the disk while maintaining the normal height, the head is lowered to a low flying height, so it is possible to suppress the frequency of contact and collision between the head and the disk. Becomes

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an HDD related to the present embodiment.
2 is a block diagram showing the configuration of the flying height control device of this embodiment, and FIG. 3 is a conceptual diagram for explaining the principle of flying height control of this embodiment. 4 is a flow chart for explaining the operation of this embodiment. (Structure of HDD) In this embodiment, an HDD adopting a ramp load method and a sector servo method is assumed. Further, as will be described later, an electrostatic attraction type flying height control device for controlling the flying height of the head is provided.

Referring to FIG. 1 below, the HDD of this embodiment
The configuration of will be described. As shown in FIG. 1, the HDD of the present embodiment has a spindle motor 7 for rotationally driving a disk 1 which is a recording medium, and a head drive mechanism for holding a head 2 and moving the disk 2 in a radial direction of the disk 1. A read / write circuit 9 for executing various signal processing for recording / reproducing data by the head 2, a microcontroller 10 as a control device, and a disk controller (HDC) 11 for controlling recording / reproducing data. I have it.

Further, the HDD of this embodiment has a support 6 which is a component of a ramp load system and a voltage control device 12 which is a component of an electrostatic attraction type flying height control device.

The disk 1 is a microcontroller 10
It is rotated at a high speed by the spindle motor 7 driven by the control of 1., and in the present embodiment, the number is one for convenience. The head 2 is actually a thin film head mounted on a slider, and is composed of only a recording / reproducing separated type head composed of an MR head and an induction type thin film head or an inductive type thin film head for both recording and reproduction.

The head drive mechanism includes a suspension 3 that supports the head 2, a head actuator 4 that holds the suspension 3, and a head actuator 4.
And a voice coil motor (VCM) 5 which is a drive source of the.

The head actuator 4 is rotationally driven in the radial direction of the disk 1 by the driving force of the VCM 5 to move the head 2 onto the disk 1. The VCM 5 is driven by the drive current supplied from the VCM driver 8 under the control of the microcontroller 10.

In the ramp load system, as shown in FIG. 1, when the disk is stationary (when the head 2 is stopped), the head actuator 4 is located outside the disk 1 and retracts the head 2. . In this state, the suspension 3 is supported on the support 6. When the disc is started, the suspension 3 moves to the head actuator 4
Is driven so as to slide down from the support 6 and move onto the disc 1.

The read / write circuit 9 has a function of performing various signal processing on a read signal read from the head 2 to reproduce data, and a data for supplying the head 2 with a write current according to the write data transferred from the HDC 11. It has a recording function.

The read / write circuit 9 has a servo processing circuit for reproducing host data (normal user data) and also for reproducing servo data. The servo data is data used for positioning control of the head 2, and is roughly classified into an address code and burst data. The read / write circuit 9 outputs the reproduced host data to the HDC 11 and the reproduced servo data to the microcontroller 10.

The microcontroller 10 includes a microprocessor (CPU) 10a, which is a main component, and an A / D.
It has a converter 10b and a D / A converter 10c. The CPU 10a executes a head positioning control process and is a constituent element of the flying height control device related to the present embodiment. That is, the CPU 10a controls the voltage control device 12 when the HDD, which will be described later, is activated to execute the process of controlling the flying height of the head 2.

The A / D converter 10b converts the burst data (position information) of the analog signal into digital data in the servo data output from the servo processing circuit of the read / write circuit 9 and outputs it to the CPU 10a.
Actually, the peak value of the burst data is held by the sample hold circuit, and this peak value (DC level) is converted into digital data.

The D / A converter 10c includes the CPU 10a.
Converts the control amount calculated based on the servo data into an analog signal and outputs it to the VCM driver 8. (Structure and Principle of Flying Height Control Device) In the flying height control device of this embodiment, as shown in FIG. 2, the voltage control device 12 applies a voltage (+ V) to the suspension 3 held by the head actuator 4. Is configured.
The voltage controller 12 is a CP of the microcontroller 10.
A voltage having a voltage level controlled by U10a is applied. Here, the disk 1 is grounded via the spindle motor 7 and is set to the reference level (-).

As shown in FIG. 3, the principle of the flying height control device is that the head (actually the slider as described above) 2 and the reference level (-) disk 1 are driven by the voltage (+ V) applied to the suspension 3. A potential difference is generated between the two.

That is, since the disk 1 is negatively charged and the head 2 is positively charged, the disk 1
An electrostatic attraction force is generated by the action of the Coulomb force between the head and the head 2.

By this electrostatic attraction force, the head 2 is attracted to the fixed disk 1 toward the disk 1 and approaches the fixed disk 1, and the flying height (flying height FH) is reduced. (Operation of this Embodiment) Hereinafter, the operation mainly relating to the flying height control related to this embodiment will be described with reference to the flowchart of FIG.

First, the power of the HDD is turned on and the spindle motor 7 is driven to start the rotation of the disk 1 (step S1). At this time, as shown in FIG. 1, the head actuator 4 is located outside the disk 1, and the head 2 is ramp-loaded (retracted) to the support 6 via the suspension 3.

When the disk 1 is in a steady rotation state due to the acceleration of the spindle motor 7, the CPU 10a causes the VCM to operate.
The VCM 5 is drive-controlled via the driver 8 to rotationally move the head actuator 4 to the disk 1 side (YES in step S2, S3).

That is, when the head actuator 4 is driven, the suspension 3 moves so as to slide down from the support 6, and the head 2 moves on the disk 1 in the radial direction. At this time, since the disk 1 is rotating at high speed, the head 2 has its air dynamic pressure (air bearing action).
It is in a state of being surfaced. The head 2 is pressed against the disk 1 by the pressing force of the suspension 3. Therefore, at a position where the aerodynamic pressure of the disk 1 and the pressing force of the suspension 3 are balanced,
The head 2 is floating.

Next, the CPU 10a instructs the head 2 to read the servo data from the disk 1. That is, the head 2 reads the servo data from the moved position (arbitrary track position) on the disk 1 and outputs a read signal to the read / write circuit 9 (step S).
4).

The read / write circuit 9 receives servo data (address code and burst data) from the read signal of the head 2 by means of the servo processing circuit, and the microcontroller 1
Output to 0. The CPU 10a checks whether or not the input servo data is normal, and if normal, moves to flying height control processing (YES in step S5, S
6).

In the flying height control process, as described above, C
A voltage (+ V) is applied from the voltage control device 12 via the suspension 3 under the control of the PU 10a. As a result, an electrostatic attraction force is generated between the head 2 and the disk 1 by the action of Coulomb force.

Therefore, as shown in FIG.
0a controls the voltage control device 12 to reduce the flying height FH of the head 2 with respect to the disk 1 and to adjust the distance between the head 2 and the disk 1 to be small.

On the other hand, when the servo data from the head 2 is not normally read, the CPU 10a
Is not moved to the data area of the disc 1 (NO in step S5).

In this case, it is estimated that the driving force of the VCM 5 is insufficient and the suspension 3 is not separated from the support 6. Moreover, the driving force of the VCM 5 is too large,
It is possible that the head 2 has moved to an area other than the innermost data area.

In any case, the CPU 10a again drives and controls the VCM 5 to move the head 2 to the inner circumference side or the outer circumference side. Then, as described above, the process shifts to the check process of the servo data read operation.

As described above, according to this embodiment, when the disk 1 is stationary, the head 2 is retracted to the outside of the disk 1 by the ramp load method and is supported in a non-contact state with the disk 1. . When the HDD is activated and the disk 1 reaches a steady rotation, the head 1 is moved onto the disk 1 and is positioned above the data area in a floating state.

At this time, the flying height of the head 1 is a height that balances the aerodynamic pressure due to the high speed rotation of the disk 1 and the pressing force of the suspension 3, and is set in advance. That is, the flying height is ensured to avoid the situation where the head 2 comes into contact with or collides with the disk 1 rotating at a high speed.

Next, in the present embodiment, an electrostatic attraction type flying height control device is used to adjust the flying height of the head 2 so as to reduce the flying height of the head 2 so as to reduce the distance from the disk 1. At this time, in this embodiment, it is checked whether or not the servo data is normally read by the head 2. When the data is normally read, the flying height of the head 2 is adjusted to be reduced.

On the other hand, when the data is not read normally, it is determined that the head 2 has not moved to the data area of the disk 1 yet, and normally the movement control is executed again. Further, the reading operation of the servo data is checked, and if the reading is performed normally, the flying height of the head 2 is adjusted to be lowered.

Here, if the servo data is not normally read out even after the movement control is performed a predetermined number of times, it is determined that a failure has occurred in the head 2, the head actuator 4, or the disk 1. For example, the operation of the HDD is stopped.

According to the present embodiment, by adopting the ramp load method, it is possible to avoid the state where the head 2 and the disk 1 are in contact with each other, so that the surface of the disk 1 can be mirror-finished without being textured. . Therefore,
The flying height of the head 2 can be reduced to the limit.

On the other hand, after confirming that the head 2 has normally moved to the data area of the disk 1 by the flying height control device, an adjusting process for lowering the flying height of the head 2 is executed. Therefore, when the head 2 is moved onto the disk 1, it is possible to prevent contact and collision with the disk rotating at a high speed.

In other words, the head 2 is moved over the data area of the disk 1 while ensuring a predetermined space, and then the ultra low flying mode is entered. Therefore, it is possible to significantly reduce the frequency of contact and collision with the disc rotating at high speed.

Before lowering the flying height of the head 2, the HDD data is checked by the servo data read operation check process.
The failure test will be executed at the time of startup. For this reason,
It is also possible to prevent a situation in which the data recording / reproducing operation is inconvenient due to a failure of the head 2, the head actuator 4, or the like.

[0049]

As described above in detail, according to the present invention, by adopting the ramp load method, the surface of the disk can be mirror-finished without being textured. In addition, after confirming that the head has normally moved to the data area of the disk, the flying height of the head can be reduced to the limit. As a result, even if the flying height of the head is lowered when the disk is started, the frequency of contact and collision between the head and the disk can be significantly suppressed. Therefore, as a result, it is possible to realize an extremely low flying height of the head, and it is possible to increase the recording density of the disk.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an HDD related to the present embodiment in the present invention.

FIG. 2 is a block diagram showing a configuration of a flying height control device according to the present embodiment.

FIG. 3 is a conceptual diagram for explaining the principle of flying height control of the present embodiment.

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

[Explanation of symbols]

 1 ... Disk 2 ... Head (slider) 3 ... Suspension 4 ... Head actuator 5 ... VCM (voice coil motor) 6 ... Support (ramp load system) 7 ... Spindle motor 8 ... VCM driver 9 ... Read / write circuit 10 ... Micro Controller 10a ... CPU 10b ... A / D converter 10c ... D / A converter 11 ... Disk controller (HDC) 12 ... Voltage control device

Claims (4)

[Claims] 1. A carriage control device for a disk recording / reproducing apparatus using a ramp load system for supporting a head in a non-contact state with the disk when the disk stands still, the carriage control apparatus supporting the head and driving force of a motor means. An actuator mechanism for moving the head in the radial direction on the disk by means of: drive control means for driving and controlling the actuator mechanism to move the head on the disk when the disk is in a steady rotation; and the drive control means. And a flying height control means for controlling the flying height of the head by detecting a movement of the head onto the disk by applying a Coulomb force between the head and the disk. Carriage controller for disk recording / playback device. 2. A disk recording method for controlling positioning of the head by reading a servo data recorded in a data area of the disk by using a ramp load method for supporting the head in a non-contact state with the disk when the disk stands still. A carriage control device of a reproducing apparatus, comprising: an actuator mechanism that supports the head and moves the head in a radial direction on the disk by a driving force of a motor means; Drive control means for driving and moving the head onto the disk; reproducing means for reproducing the servo data read from the disk by the head; and the head for applying a potential difference between the head and the disk. And Coulomb force between the disc and the disc Voltage control means for adjusting the flying height of the head; and the voltage control means when the head is moved onto the disk by the drive control means and the servo data is normally reproduced by the reproducing means. A disk recording / reproducing apparatus comprising: a flying height control means for controlling a flying height of the head so as to bring the head closer to the disk side by applying a Coulomb force between the head and the disk. Carriage controller. 3. A disk recording / reproducing apparatus which uses a ramp load method of supporting a head in a non-contact state with the disk when the disk is stationary and moves the head while floating above the disk when recording / reproducing data. Of the carriage control device, the step of driving the actuator mechanism that supports the head to move the head onto the disk when the disk rotates steadily, and detecting that the head moves onto the disk. After that, a Coulomb force is applied between the head and the disk to control the flying height of the head, and the head flying control method. 4. A disk recording method for controlling the positioning of the head by reading a servo data recorded in a data area of the disk by using a ramp load method for supporting the head in a non-contact state with the disk when the disk stands still. A carriage control device of the reproducing apparatus, wherein during the steady rotation of the disc, driving and controlling the actuator mechanism to move the head onto a data area of the disc; and reading the servo data from the disc by the head. And a step of applying a Coulomb force between the head and the disk to control the flying height of the head so as to bring the head closer to the disk side when the servo data is normally read. And a method for controlling the flying height of the head.