JP2002109841A - Recording method of servo signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording method of servo signals through which recording of spike noise caused by extra pulses at the boundary between the servo signals and a data section is prevented and to manufacture a highly reliable magnetic recording medium that produces no maloperation of a drive caused by the spike noise. SOLUTION: When the magnetic recording medium is rotated at a prescribed rotational speed and servo signals is recorded, in a recording section and a non-recording section that are alternately formed, a recording current supplied to a recording head at the recording completion time of servo signals which existed immediately before the servo signal to be recorded this time is maintained in the non-recording section of the signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of manufacturing magnetic recording media such as flexible disks and hard disks, and more particularly, to recording of servo signals capable of greatly reducing malfunction of a recording / reproducing drive of a magnetic recording medium. About the method.

[0002]

2. Description of the Related Art Conventionally, a flexible disk which has magnetic layers on both sides of a disk-shaped base made of a flexible polyester sheet or the like and on which signals are recorded or reproduced by a magnetic head is used as a magnetic recording medium. It is offered as a kind. Such a flexible disk is usually provided as a disk cartridge in which a hard hub is mounted at the center of the disk and the entirety is housed in a plastic case. It is mainly used as a recording medium for a computer.

In such a flexible disk, signal recording / reproduction is performed by a so-called magnetic head. In a flexible disk with a small storage capacity, the positioning of the magnetic head when recording / reproducing a signal
It is performed by open loop control. On the other hand, in a large-capacity flexible disk in which the recording density is increased and the storage capacity is increased, it is necessary to position the magnetic head by close-loop control. Therefore, in a large-capacity flexible disk, it is necessary to record a servo signal for positioning the magnetic head when recording / reproducing a signal.

[0004] Recording of servo signals on a flexible disk is performed by a so-called servo track writer. When the disk is set, the servo track writer holds the hub of the flexible disk with a spindle for rotational drive, loads the magnetic head on the flexible disk, and then rotates the flexible disk with the spindle while rotating the flexible disk. In general, a servo signal is recorded while moving a magnetic head in a direction (see Japanese Patent Application Laid-Open No. 9-180418).

[0005]

Generally, such servo signals are recorded at predetermined intervals on a circle (track) whose center coincides with the center of rotation of the flexible disk. That is, a large number of concentric circles in which servo signals and non-recording portions (data portions) of the servo signals are alternately formed on the flexible disk.

[0006] The original purpose of a servo track writer is to record an appropriate servo signal at a predetermined location. Therefore, in the servo track writer, the recording current of the signal to be supplied to the magnetic head is turned off in the data section so that an unnecessary signal is not recorded. However, in this method, an extra pulse is generated at the boundary between the servo signal and the data portion, and a pseudo signal (spike noise) may be recorded, which is a problem.

FIG. 3 shows an example of a signal output when a flexible disk on which a servo signal is recorded is reproduced by a recording / reproducing drive (the horizontal axis is the rotation direction). In this example, the servo signal is a region indicated by a in the drawing, and the other region indicated by b in the drawing is a data portion. As shown in FIG. 3, in the conventional servo signal recording in which the recording current of the signal supplied to the magnetic head is interrupted when the recording of the servo signal is completed, the servo signal in which the recording current is interrupted and the data portion are recorded. At the boundary between
Spike noise due to extra pulses may be recorded.

The spike noise formed at the boundary between the servo signal and the data portion may be rarely erroneously recognized as a meaningful signal in a recording / reproducing drive. This is a problem as a cause of a drive malfunction that causes a playback error.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. In manufacturing a magnetic recording medium such as a flexible disk or a hard disk, a servo signal is recorded at a boundary between the servo signal and a data portion. Unnecessary signals due to the extra pulse, that is, spike noise can be prevented from being recorded, and there is no malfunction of the recording / reproduction drive due to the spike noise. Therefore, there is no data recording / reproduction error due to this malfunction. An object of the present invention is to provide a servo signal recording method capable of manufacturing a highly reliable magnetic recording medium.

[0010]

In order to achieve the above object, the present invention provides a servo signal recording section which is formed alternately when a magnetic recording medium is rotated at a predetermined rotation speed to record a servo signal. And a non-recording portion, wherein the non-recording portion of the servo signal maintains a recording current supplied to the recording head at the end of recording of the immediately preceding servo signal.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a servo signal recording method according to the present invention will be described in detail.

FIG. 1 is a schematic diagram showing an example of a servo track writer (hereinafter, referred to as a servo writer) for implementing a servo signal recording method according to the present invention. The following description is an example in which the present invention is used for recording a servo signal on a flexible disk. However, the present invention is not limited to this, and any disk-shaped (disk-shaped) magnetic recording medium may be used. It can be used for recording servo signals on various magnetic recording media such as hard disks.

The servo writer shown in FIG. 1 records servo signals for moving and positioning a magnetic head on a flexible disk 10 (hereinafter, referred to as a disk 10). Means 14
And a magnetic head unit 16. These are installed at predetermined positions on the surface plate 18. In the center of the disk 10, a hub (center core) 1
2 is mounted, and a center hole is formed at the center of the hub 12.

The rotating means 14 has a rotary drive source 20, a spindle 22 rotated by the rotary drive source 20, and a hub chuck 26 having a center pin 24 at the center of rotation and arranged at the tip of the spindle 22. When recording a servo signal on the disk 10, the hub chuck 26
However, the center pin 24 is inserted into the center hole of the hub 12, and the hub 12 is chucked by a known means to hold the disk 10. In this state, the rotation drive source 20 is driven to rotate the spindle 22, thereby rotating the disk 14 at a predetermined speed (for example, 3600 rpm).

Incidentally, the flexible disk is usually provided as a disk cartridge entirely housed in a plastic case as shown by a dashed line in the figure. The flexible disk used in the recording method of the present invention may be stored in a case or may not be stored, but usually, the flexible disk is
The recording method according to the present invention is provided in a state stored in a case. When recording the servo signal on the disk 10 stored in the disk cartridge, if the disk cartridge is supplied with a shutter member that opens / closes the window for inserting the magnetic head, this shutter member is used. A known opening / closing mechanism for opening / closing is arranged.

In the rotating means 14, a clock disk 28 composed of a hard disk is fixed on the spindle 22 coaxially with the rotation of the disk 10, and a clock head 30 for recording / reproducing a clock signal (reference pulse) on / from the clock disk 28. Is arranged. At the time of recording the servo signal, the rotation angle of the disk 10 is detected by the clock signal read from the clock disk 28 by the clock head 30, and the servo signal of the magnetic head 32 (32a and 32b) described later is accordingly A record is made.

The magnetic head unit 16 (hereinafter, referred to as the head unit 16) records a servo signal on the disk 10 using the magnetic head 32. The servo writer in the illustrated example is for recording a servo signal on a sector servo type disk 10 having both surfaces as data surfaces, and the upper side (one surface side) of the magnetic disk is sandwiched between both surfaces of the disk 10. The head 32a and the lower side (0
(Surface side). Both magnetic heads 32
Is a known magnetic head having a slider, a head gimbal, and the like on which a head element is formed and used for recording a servo signal on a disk-shaped recording medium which floats by rotation of the disk 10 and which is servo-controlled by a known means. A signal recording current is supplied.

The two magnetic heads 32 include a suspension 34
(34a and 34b) are attached to the head base 36. The head base 36 is held by a linear guide 40 mounted on a base 38 fixed to the surface plate 18 so as to be able to reciprocate (hereinafter referred to as a radial direction) toward the center of rotation of the disk 10. The head base 36 has a VCM (voice coil motor) 42
Are engaged. In the head unit 16, by moving the head base 36 in the radial direction by the VCM 42, the magnetic head 32 is moved in the radial direction, and the magnetic head 32 is moved to a position corresponding to the surface of the disk 10 (load). Evacuate from the same position (unload),
The disk moves to a recording position on the surface of the disk 10 (seek).

In the illustrated example, the head unit 16 has a laser length measuring means 44. As the laser length measuring means 44, a laser light having a laser light source 46, a half mirror 48, a reflector 50 fixed to the head 32 at the opposite end in the radial direction of the head base 36, and a light receiving section 52 was used. This is a known length measuring means.

The laser light emitted from the laser light source 46 enters and passes through the half mirror 48 from the back surface, enters the reflector 50, is reflected, is reflected by the surface of the half mirror 48, and enters the light receiving section 52. . The laser length measuring unit 44 measures the distance between the laser light source 46 (or the light receiving unit 52) and the head base 36 by measuring the laser beam incident on the light receiving unit 52. The servo writer in the illustrated example detects the position of the magnetic head 32 from this distance, and controls recording of a servo signal and the like.

In such a servo writer, the spindle 22, clock head 30, magnetic head 32, VC
The M42, the light receiving unit 52, and the like are connected to control means (not shown), and their operations and positions are detected by the control means, and various controls are performed. Under this control, VCM42
The magnetic head 32 is sought by the
The servo signal is recorded on the disk 10 by the magnetic head 32 while rotating 0 at a predetermined speed.

As is well known, in a flexible disk (disk-shaped magnetic recording medium), a magnetic head 32 is used.
Servo signals for movement and positioning of the disk are provided at predetermined intervals on a circle whose center coincides with the center of rotation of the disk 10.
For example, it is recorded at a predetermined angular interval. Accordingly, the disk 10 has a large number of concentric circles (tracks) including the servo signal (servo signal portion = servo field) and the non-recording portion (data portion (data field)) in the same center.
Is formed.

Here, in the present invention, in recording a servo signal that alternately forms a servo signal and a data portion on a circle, even if recording of one servo signal is completed, the recording current is not interrupted. The state at the end of recording of the immediately preceding servo signal is maintained, and the recording current of the signal is also applied to the magnetic head 3 in the data portion.
Feed to 2. Except for this point, the servo signal recording method of the present invention records a servo signal in the same manner as a normal method. Therefore, the servo signal to be recorded is not particularly limited. For example, a servo AGC (Automatic Gain Control)
l), a known servo signal for moving and positioning the magnetic head, which has a servo mark, a gray code address, a servo pattern, and the like.

As described above, in the conventional servo signal recording method, the data portion interrupts the recording current of the signal supplied to the magnetic head 32. Therefore, FIG.
As shown by, at the boundary between the servo signal and the data part,
Spike noise due to extra pulses is recorded. In rare cases, this signal is erroneously recognized as a signal that is meaningful in the recording / reproducing drive of the disk 10, causing the drive to malfunction and causing a data (signal) recording / reproducing error.

Here, in order to eliminate such spike noise, that is, unnecessary extra pulses, an unnecessary magnetization reversal pattern need not be generated on the disk 10 in recording a servo signal by a servo writer.
According to the present invention, in the recording of the servo signal on the disk 10, the recording current of the signal supplied to the magnetic head 32 is not interrupted even in the data portion, and the recording current at the end of the recording of the immediately preceding servo signal is maintained (volume). And the recording current is supplied to the magnetic head 32 until the next servo signal is recorded (with the direction (+ or − direction) as it is). That is, in the servo signal recording method of the present invention, the recording current is always supplied to the magnetic head 32 during the recording of the servo signal for one round, and only the servo signal recording section responds to the servo signal to be recorded. To change the direction of the recording current. This can prevent the generation of extra pulses and prevent the recording of unnecessary signals at the boundary between the servo signal recording portion and the data portion, that is, spike noise.

It should be noted that the recording current is turned on during a seek operation or the like.
Since / off is performed in the data portion where the servo signal is not recorded, even if spike noise occurs at this time, it is erased by actual data recording, so there is no problem.

FIG. 2 shows a disc 10 according to the recording method of the present invention.
2 shows an example of a signal output when the servo signal recorded in (1) is reproduced by a recording / reproduction drive of a (flexible) disk. FIG. 2 (similarly to FIG. 3 described above) reads a change in the magnetic flux of the recorded magnetic information, converts the read magnetic flux into a voltage value, and outputs the voltage value. The horizontal axis indicates the rotation direction. In FIG. 2, as in FIG. 3, the area indicated by a in the figure is the servo signal, and the other area indicated by b in the figure is the data portion. As shown in FIG. 2, according to the present invention, the signal current at the end of the recording of the servo signal is maintained and supplied to the magnetic head 32 without interrupting the recording current in the data portion. Since no extra pulse is generated, no spike noise is recorded at the boundary between the servo signal and the data portion.

Therefore, according to the servo signal recording method of the present invention, when data is recorded / reproduced on / from the disk by the recording / reproducing drive, there is no malfunction of the drive due to spike noise, and the data can be recorded accordingly. It is possible to manufacture a highly reliable disk 10 in which recording / reproducing errors do not occur.

While the servo signal recording method of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various improvements and changes are made without departing from the scope of the present invention. Of course, it is good.

[0030]

As described above in detail, according to the servo signal recording method of the present invention, an unnecessary signal due to an extra pulse, that is, a spike noise is recorded at a boundary between the servo signal and the data portion. Will not be
It is possible to manufacture a highly reliable magnetic recording medium in which there is no malfunction of the recording / reproducing drive caused by the spike noise and no data recording / reproducing error due to this.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an example of a servo track writer that performs a servo signal recording method of the present invention.

FIG. 2 is a graph showing an output signal when an example of a servo signal recorded by the servo signal recording method of the present invention is reproduced.

FIG. 3 is a graph showing an output signal when an example of a servo signal recorded by a conventional servo signal recording method is reproduced.

[Explanation of symbols]

 Reference Signs List 10 (flexible) disk 12 core 14 rotating means 16 (magnetic) head unit 18 surface plate 20 rotation drive source 22 spindle 24 center pin 26 hub chuck 28 clock disk 30 clock head 32 magnetic head 34 suspension 36 head base 38 base 40 linear Guide 42 VCM (voice coil motor) 44 Laser length measuring means 46 Laser light source 48 Half mirror 50 Reflector 52 Light receiving unit

Claims (1)

[Claims] A magnetic recording medium is rotated at a predetermined rotational speed,
When recording the servo signal, the recording current supplied to the recording head at the end of the recording of the immediately preceding servo signal is maintained in the non-recording part of the servo signal in the recording part and the non-recording part of the servo signal formed alternately A recording method of a servo signal, characterized in that: