JP2002056642A - Servo writer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a servo writer which secures a satisfactory cleaning operation so as to eliminate the defective servo signal writing operations while reducing the increase of driving torque of its high density magnetic disk media. SOLUTION: This servo writer writes the head positioning servo signal to a magnetic disk cartridge which stores the high density magnetic disk media in a case in their rotatable ways. The servo writer is provided with a magnetic head which performs the recording/reproducing operations and a cleaning member which is placed adjacent at least to the side edge set at the upstream side to the revolving directions of those magnetic disk media and touches the surfaces of magnetic disk media while they are revolving.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servo writer, and more particularly to a servo writer for positioning a head with respect to a magnetic disk medium of a magnetic disk cartridge rotatably housed in a case. Write signals (hereinafter referred to as servo write)
Related to a servo writer.

[0002]

2. Description of the Related Art As is well known, magnetic layers are conventionally formed on both sides of a disk-shaped support made of a flexible polyester sheet or the like, and magnetic recording is performed on the magnetic layers by a magnetic head while rotating. There is provided a magnetic disk cartridge in which a magnetic disk medium is accommodated in a case. This magnetic disk cartridge is mainly used as a recording medium for a computer because of its advantages such as easy handling and low cost.

In such a magnetic disk cartridge, the positioning of the magnetic head with respect to a track formed concentrically on the magnetic disk medium is performed by open loop control when the storage capacity is small. Increase track density by 150 to increase
In the case of a high density (high track density) of 200 TPI or more, it is necessary to position the magnetic head by closed loop control, and it is required to write a servo signal before shipping a product (magnetic disk cartridge). You.

[0004] When writing the servo signals to the medium (magnetic disk medium) of a large number of magnetic disk cartridges, a drive for holding the magnetic disk cartridge and rotating the magnetic disk medium is provided with a magnetic signal for writing the servo signal. It has been common practice to install a large number of servo write devices (servo writers) each having a head, manually insert a magnetic disk cartridge into the servo write device, and take out a magnetic disk cartridge on which servo signals have been written. .

Recently, various devices have been proposed which automate the supply and recovery (removal) of a magnetic disk cartridge to and from the servo write device.
Specifically, for example, an apparatus has been proposed which automates the supply and recovery (removal) of a magnetic disk cartridge by means of a transfer means such as a transfer robot, and a certain effect is being recognized.

As described above, it is important to ensure the reliability of a magnetic disk cartridge on which a servo signal is written. In order to ensure this reliability, it is important that dust that causes so-called dropout does not adhere to the magnetic disk medium or the magnetic head. Some of the dust are generated inside the magnetic disk cartridge and others are intruded from the outside, but it is difficult to completely prevent the generation and intrusion.

For this reason, conventionally, a liner made of non-woven fabric or the like is provided on the inner surface of the case to wipe off dust adhering to the magnetic disk medium, and this liner is lightly contacted with the surface of the magnetic disk medium by a lifter. Cleaning has also been performed.

[0008]

However, in recent years,
As the recording capacity of the magnetic disk media has been increased, the magnetic disk cartridge has been correspondingly rotated at a higher speed. In order to ensure the stability of the driving torque and the torque capability of the motor, the liner is required. Tend to reduce or substantially reduce the contact pressure to zero. Along with this, the dust removal effect on the surface of the magnetic disk medium by the liner is reduced, and problems such as occurrence of dropout due to accumulation of dust attached to the magnetic disk medium in the head gap of the magnetic head become remarkable. It has been needed.

For example, a large-capacity magnetic disk cartridge to which the present invention is applied employs a method of shortening the recording wavelength and rotating the magnetic disk medium at a high speed of 3600 rpm or the like in order to secure a transfer rate. On the other hand, with this large-capacity magnetic disk cartridge driving device, it is necessary to enable low-speed rotation drive in order to enable recording / reproducing with respect to a conventional magnetic disk cartridge having a lower recording capacity. It is necessary that the drive motor supports a low-speed to a high-speed rotation and obtains a certain or more rotational torque.

[0010] Further, this drive device needs to be compatible with a desktop personal computer to a light and thin notebook type personal computer. The drive motor is required to be low power and thin, and it is difficult to obtain a high rotation torque. It is in.
In consideration of these points, as described above, the driving torque of the magnetic disk medium of the large-capacity magnetic disk cartridge is as small as possible, that is, the magnetic disk medium has as little interference as possible when the magnetic disk medium rotates at a high speed. Is required.

In addition, the presence of particles (protrusions) generated in the process of manufacturing this type of high-density magnetic disk media,
Foreign matter attached during the process often causes write failure during servo signal writing, in which case the sector becomes a defective sector. It is preferable to remove dust and the like before writing the servo signal.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to solve the above-mentioned problems in the prior art and to reduce the driving torque of a high-density magnetic disk medium in a servo writer. It is an object of the present invention to provide a servo writer which can obtain a good cleaning action while reducing an increase and eliminate a servo signal writing defect.

[0013]

In order to achieve the above object, a servo writer according to the present invention is provided for positioning a head on a magnetic disk cartridge in which a disk-shaped high-density magnetic disk medium is rotatably accommodated in a case. A servo writer of a magnetic disk cartridge for writing a servo signal, comprising a magnetic head for performing recording and reproduction, at least on the side edge of the magnetic head on the upstream side in the rotation direction of the magnetic disk medium, when the magnetic disk medium rotates. A cleaning member that contacts the surface is disposed adjacent to the cleaning member.

In the servo writer of the present invention configured as described above, the cleaning member contacts the surface of the high-density magnetic disk medium locally with the rotation of the high-density magnetic disk medium. The cleaning member also moves with the movement of the magnetic head in the radial direction from the center to the outer periphery of the high-density magnetic disk medium, and cleans the minimum necessary surface of the magnetic disk medium where recording and reproduction are performed by the magnetic head. .

The cleaning action is not limited to dust adhering after the manufacture of the high-density magnetic disk medium, but also includes the presence (projections) of particles generated during the manufacturing process of this type of high-density magnetic disk medium. In addition, a so-called "burnish" action, which removes foreign substances and the like adhered in the process, is also included.

This cleaning and "burnish"
By this function, protrusions generated on the high-density magnetic disk medium and foreign substances and dust attached to the surface of the medium can be scraped off. Since defects do not occur, the effect of improving the product yield can be obtained.

In the servo writer according to the present invention,
It is preferable that the cleaning member moves in the same manner as the magnetic head when the operation of the magnetic head starts or ends in conjunction with the movement of the magnetic disk medium. Of course, only cleaning of the magnetic disk medium may be performed once over the entire circumference, and then recording and reproduction may be performed by the magnetic head.

In the servo writer according to the present invention, the cleaning member may be supported integrally with the magnetic head. Alternatively, the cleaning member may be supported by a suspension member provided separately and separately from the magnetic head. It may be arranged near the part.

As described above, when the cleaning member is provided so as to move substantially in the same manner in connection with the movement of the magnetic head at the start or end of the operation of the magnetic head, it is possible to operate the magnetic head. And a good cleaning action can be obtained. In particular, by supporting the cleaning member with a suspension member provided integrally with or separate from the magnetic head, movement following the movement with the magnetic head can be secured, and highly accurate positioning can be achieved.

In the servo writer according to the present invention, the cleaning member is formed of a non-woven fabric, a long fiber cloth, a brushed body, a fiber brush, or the like, and the tip of the cleaning member is lightly applied to the surface of the magnetic disk medium during high-speed rotation. Set to touch. It is also possible to use a hard ceramic member (for example, sapphire) having a scraping function, a so-called scraper function.

[0021]

Embodiments of the present invention will be described below in detail with reference to preferred embodiments shown in the accompanying drawings.

FIG. 1 is a plan view showing a main part of a servo write system using a plurality of servo writers according to an embodiment of the present invention, and FIG. 2 is a front view thereof. As can be seen from both figures, in the servo write system according to the present embodiment, six servo writers 10 are linearly arranged. That is, in the servo write system according to the present embodiment, the transfer robot 31 described below travels in front of the six servo writers 10 arranged linearly.

As shown in FIG. 3, the servo writer 10 includes a mounting table 11 for receiving a magnetic disk cartridge 1 in which a magnetic disk medium 3 is rotatably accommodated in a case 2, and a magnetic disk on the mounting table 11. And a holding table 12 for holding the cartridge 1 at the servo write position. The magnetic disk cartridge 1 before writing the servo signal, which is transported by the transport robot 31 described later, is supplied to the mounting table 11. The magnetic disk cartridge 1 on which the servo signal has been written by the servo writer 10 is transported by the transport robot 31 to a predetermined accumulation position.

As the servo writer 10, here,
A servo write device (servo) provided with a mechanism in which a magnetic disk cartridge is dropped and supplied from a transfer robot onto a mounting table, which was previously proposed by the present applicant in Japanese Patent Application No. 11-116372, "servo write device for magnetic disk cartridge". Writer), but the present invention is not limited to this, and a device provided with another supply mechanism can be used.

That is, as described above, the servo writer 10 includes a mounting table 11 for receiving the magnetic disk cartridge 1 in which the magnetic disk medium 3 is rotatably accommodated in the case 2, and a magnetic table on the mounting table 11. A holding table 12 for transferring the disk cartridge 1 and holding the disk cartridge 1 at a servo write position is provided on a table 14.

As shown in FIG. 4, the magnetic disk cartridge 1 which has been transported by the transport robot 31 and before the servo signal is written is dropped and supplied to the mounting table 11. The mounting table 11 is formed in a rail shape extending in parallel along both sides of the mounting position, and a receiving surface 11a for receiving the lower surface of the side of the magnetic disk cartridge 1 supplied by being dropped.
And an inclined guide surface 11b extending obliquely upward from the side of the receiving surface 11a.

The inclined guide surface 11b of the mounting table 11 is provided with the magnetic disk cartridge 1 which is supplied by being dropped and moved by its own weight.
Guides both sides to correct the movement to a predetermined position. Also,
At least the inclined guide surface 11b is formed of a low-friction material (for example, plastics having lubricity such as Delrin).

The holding table 12 is provided with the mounting table 11 described above.
Are arranged in a rail shape on the extension line of the magnetic disk cartridge 1 and are positioned and held on both sides of the magnetic disk cartridge 1 moved from the mounting table 11 by a drawing mechanism (not shown). The magnetic disk cartridge 1 held by the holding table 12
The magnetic disk medium 3 is exposed at a magnetic head insertion opening 5 opened by opening the shutter 4.

A spindle 13 for rotatably driving the magnetic disk medium 3 is provided at the center of the holding table 12, and a magnetic head 1 for servo writing is provided beside the spindle 13.
5 is provided. The spindle 13 chucks the upper end of the magnetic disk medium 3 by a method such as magnetically attracting the center core of the magnetic disk medium 3. The spindle 13 is rotated at a high speed by a motor (not shown) to maintain the magnetic disk medium 3 in a predetermined rotation state. Having.

The servo write magnetic head 15
A linear guide is disposed at the tip of the suspension member 16 so as to vertically sandwich the magnetic disk medium 3 therebetween, and is provided on a base 17 so as to be able to reciprocate toward the center of the spindle 13. 20 and the like. The load mechanism detects the position of the magnetic head 15 for servo write, performs the positioning, and drives the actuator (VCM current control).

The servo write by the servo writer 10 constructed as described above is performed by rotating the magnetic disk medium 3 at a predetermined rotational speed with the spindle 13 holding the center core of the magnetic disk medium 3 by suction. The head 15 is loaded at a predetermined position on the surface of the magnetic disk medium 3, and a predetermined servo pattern is synchronized with the clock signal (for example, from the outer circumference to the inner circumference or from the inner circumference to the outer circumference of the magnetic disk medium 3; (Sequential) writing.

When the servo writing of all the predetermined tracks is completed, the magnetic head 15 for servo writing is retracted from the spindle 13 and the rotation of the spindle 13 is stopped. The cartridge 1 is moved from the holding table 12 to the mounting table 11 by reversing the drawing means (not shown), and the processed magnetic disk cartridge 1 is taken out by the transfer robot 31. Set the cartridge 1 on the spindle 13 and
Similarly, servo write is performed.

As shown in FIG. 1, a transfer robot (transfer means) 31 which can move in parallel with the arrangement direction, and the servo writer 10 with the transfer robot 31 interposed therebetween. Supply station 32 and accumulation station 33 disposed at a position facing the
And 34 are provided.

The supply station 32 stores and holds the magnetic disk cartridge 1 before the servo write process (unprocessed).
Numerals 4 respectively accumulate the magnetic disk cartridge 1 on which the servo write processing has been normally performed and the magnetic disk cartridge 1 on which the servo write processing has not been normally performed. That is, the accumulation station 33 is a normal product accumulation station, and the accumulation station 34 is a defective product accumulation station.

Along with the above stations, an operation panel 35
Are arranged. As shown in FIG. 5, the transfer robot 31 has a first arm (supply arm) 41 and a second arm (accumulation arm) 42 that extend in two directions at a predetermined angle on the support 40. , These two arms 41, 42
A suction cup 43 for sucking and holding the upper surface of the magnetic disk cartridge 1 is provided at a lower part of the tip of the magnetic disk cartridge 1.

The two arms 41 and 42 are configured so as to be integrally rotated about a support 40 by a rotation mechanism 44 including a rotation actuator. In addition, the support section 40 includes a lifting mechanism 4 including a lifting actuator.
5 to move up and down and travel along the arrangement direction of the mounting table 11 by a traveling mechanism 46 including a traveling actuator. 1 and 2
The safety fence is shown in broken lines.

The above-described supply station 32, normal product accumulation station 33, and defective product accumulation station 34
Have almost the same configuration, in which a cylindrical rotating body 51 is provided with three vertically movable holders 52, and a large number of magnetic disks are mounted on these holders 52. Cartridge 1 can be integrated,
The holders 52 are individually moved up and down in accordance with the loading amount, and the upper surface of the magnetic disk cartridge 1 integrated there is configured to substantially coincide with the upper surface of the rotating body 51 described above.

The rotating body 51 is configured to be rotated by a rotating mechanism 53 including a rotary actuator, and the three holders 52 are configured to be vertically movable by a lifting mechanism 54 including a lifting actuator. ing. The operation of the servo write system configured as described above will be described below.

First, the first arm 4 of the transfer robot 31
1 moves to a position facing the supply station 32, and sucks and holds the magnetic disk cartridge 1 that has not been servo-processed (meaning that the servo signal writing process has not yet been completed) by the suction cup 43 of the suction station 43. After traveling, the servo writer 10 moves to a position facing the mounting table 11 of the predetermined servo writer 10, and drops the magnetic disk cartridge 1 held on the mounting table 11.

More specifically, when the magnetic disk cartridge 1 is held by suction and when the magnetic disk cartridge 1 is held by suction on the mounting table 11 of the servo writer 10 as described above.
When dropped and supplied, the first arm 41 of the transfer robot 31 moves up and down by a very small height as necessary, thereby reliably performing the suction / supply operation.

The magnetic disk cartridge 1 supplied onto the mounting table 11 of the servo writer 10 is, as described above,
The magnetic head 15 is transferred to the holding table 12 by a retraction mechanism (not shown). The spindle 13 holds the center core of the magnetic disk medium 3 by suction and is rotated at a predetermined rotation speed. Thus, predetermined servo signals (patterns) are sequentially written.

After the servo signal writing process is completed, the magnetic disk cartridge 1 is moved from the holding table 12 of the servo writer 10 to the mounting table 1 by the reverse operation of the above-described retracting mechanism.
Transferred to 1. Subsequently, the aforementioned second arm 42 is
With the magnetic disk cartridge 1 on which the servo signal writing process is completed being sucked and held from the mounting table 11, the transport robot 31 rotates and travels and moves to the normal product accumulation station 33 or the defective product accumulation station 34.

Next, similarly to the above-described initial operation, the first arm 41 of the transfer robot 31 moves to the supply station 23 to suck and hold the next non-servo-processed magnetic disk cartridge 1. Is supplied to the mounting table 11 of the servo writer 10 for which the servo processing has been completed. By repeating this operation, supply / recovery of the magnetic disk cartridge 1 to / from each servo writer 10 is performed.

Hereinafter, the cleaning operation of the surface of the magnetic disk medium 3, which is a characteristic operation of the servo writer 10 according to the present embodiment, will be described. FIG.
FIG. 3 is a perspective view schematically showing a driving state of a magnetic disk cartridge 1 in the servo writer 10 according to the embodiment. In this figure, the magnetic head and the magnetic disk medium are shown at different ratios.

The servo writer 10 according to the present embodiment
As described above, the magnetic disk medium 3 accommodated in the magnetic disk cartridge 1 is brought into contact with both surfaces of the magnetic disk medium 3 while being sandwiched by the magnetic head 15 for servo write mounted on the tip of the suspension member 16 by a leaf spring. The magnetic disk medium 3 is rotated in a fixed rotation direction (direction of arrow A), and recording (reproduction) of a servo signal is performed by the servo write magnetic head 15 (specifically, the head gap portion) in a contact state. Do.

Depending on the type of the magnetic disk cartridge 1, the rotational direction of the magnetic disk medium 3 may be the direction indicated by the arrow B in the drawing, but the magnetic head assembly (magnetic head assembly) having the configuration shown in FIG. apparatus)
Then, it is possible to function in exactly the same way in either rotation direction.

The servo write magnetic head 15 is provided with a base member 60 fixed to the suspension member 16.
A slider 65 is provided on the base member 60 (not shown in detail). The slider 65 is provided with a protruding rail on a surface facing the surface of the magnetic disk medium 3, and a part of the slider 65 is provided. A thin-film magnetic head having a head gap for recording and reproduction is fixedly attached thereto.

The slider 65 of the servo write magnetic head 15 has a pressure which flies above the surface of the magnetic disk medium 3 due to the air flow generated by the rotation of the magnetic disk medium 3 according to the set shape, or the slider 65. The magnetic disk medium 3 comes into contact with and separates from the surface as the magnetic disk medium 3 rotates at a high speed. The contact load of the servo write magnetic head 15 is set to a predetermined value depending on the relationship with the urging force of the suspension member 16 (leaf spring).

A cleaning member 66 composed of a nonwoven fabric, a long-fiber cloth, a raised body, a fiber brush, or the like is provided adjacent to both sides of the magnetic head 15 for servo write. To attach the cleaning member 66, the plate-like base member 60 of the servo write magnetic head 15 is extended laterally to provide an attachment portion 61, and the cleaning member 66 made of a soft material is fixed to the lower surface of the attachment portion 61. ing.

The cleaning surface 62 (wiping surface) of the cleaning member 66 which comes into contact with the magnetic disk medium 3.
Is provided at the same height as the servo write magnetic head 15 (head gap portion). In the recording / reproducing state where the magnetic disk medium 3 is rotating at a high speed, the leading end cleaning surface 62 of the magnetic disk medium 3 Lightly contacts the surface to remove dust adhering to the magnetic disk medium 3, and the dust is removed from the magnetic head 15 for servo write.
Acts to prevent intrusion into the side.

The cleaning member 66 is provided as described above.
The contact surface portion is formed of a material that does not generate dust that causes dust. For example, as described above, the contact surface portion is formed of a nonwoven fabric, a long fiber cloth, a raised body, a fiber brush, or the like.
Further, the entire cleaning member 66 may be formed of the above-mentioned material, or the above-mentioned material may be fixed to the surface of a soft material such as plastic or rubber. Further, it is also possible to use a hard ceramic member and install a cleaning member for removing the dust so as to scrape it off.

Although FIG. 6 shows only one surface of the magnetic disk medium 3, the magnetic disk medium 3
The servo write magnetic head 15 provided with a cleaning member 66 similar to the above is also supported by the suspension member 16 and disposed on the opposite surface to the magnetic disk 15 by the upper and lower servo write magnetic heads 15. The magnetic disk medium 3 is stably rotated by being brought into contact with the medium 3 sandwiched therebetween.

The cleaning member 66 moves the servo write magnetic head 15, that is, moves the servo write magnetic head 15 toward and away from the surface of the magnetic disk medium 3 with the rotation of the magnetic disk medium 3, and moves the magnetic disk medium 3. The magnetic head 15 moves in accordance with the movement of the servo write magnetic head 15 in the radial direction, and is always positioned in front of the servo write magnetic head 15 (in front of the magnetic disk medium 3 in the rotation direction) to perform the cleaning action.

The contact with the surface of the magnetic disk medium 3 for the cleaning action is a very small partial contact with the entire area of the magnetic disk medium 3. Since the drive loss of the rotational torque is extremely small, the high-speed rotation of the magnetic disk medium 3 can be stably and reliably performed by a small drive motor.

The cleaning member 66 is provided between the servo write magnetic head 15 and the suspension member 1.
6 can be slightly displaced by an amount corresponding to the deformation of the side spring portion, and is slightly displaced in accordance with collision with foreign matter, contact resistance with the surface of the magnetic disk medium 3, and the like. Is the same as

FIG. 7 shows another embodiment of the present invention. Although the basic structure is not shown, it is the same as the embodiment shown in FIG. Only the direction (angle) is different. In other words, the cleaning member 66 located on the upstream side of the servo write magnetic head 15 with respect to the rotation direction A of the magnetic disk medium 3 has a center line toward the rotation center S of the magnetic disk medium 3 (a direction orthogonal to the rotation direction A). ), A bias angle of several degrees or less, for example, 2 degrees (in the figure:
θ) so as to be inclined outward.

When the cleaning member 66 biased as described above collides with a foreign substance adhering to the magnetic disk medium 3, the cleaning member 66 flies the foreign substance outward and causes the magnetic disk medium 3 to rotate. It is carried by the accompanying outward airflow and is removed to the outside of the magnetic disk medium 3. Thereby, the cleaning member 66 requires less wiping by wiping, the contact with the surface of the magnetic disk medium 3 can be reduced, and the torque loss in driving the magnetic disk medium 3 can be further reduced. In this case, the cleaning member 6
6 may be made of a hard ceramic member.

In the above embodiment, the cleaning member 6 is moved in the rotation direction A of the magnetic disk medium 3.
6 on both sides of the magnetic head 15 for servo write,
Although the weight balance of the magnetic head portion is maintained, the cleaning member 66 is provided only for the portion on the upstream side in the rotation direction of the magnetic disk medium 3 with respect to the servo write magnetic head 15. Is also good.

The above embodiment is merely an example of the present invention, and it goes without saying that the present invention is not limited to this.

[0060]

As described above in detail, according to the present invention, it is possible to obtain a good cleaning action while reducing the increase in the driving torque of the high-density magnetic disk medium in the servo writer, and obtain a servo signal writing defect. Thus, an effect is obtained that a servo writer that eliminates the problem can be realized.

That is, in the servo writer according to the present invention, the cleaning member locally contacts the surface of the high-density magnetic disk medium as the high-density magnetic disk medium rotates, The cleaning member also moves with the movement of the magnetic head in the radial direction from the center to the outer periphery of the magnetic disk, and cleans the minimum necessary surface of the magnetic disk medium where recording and reproduction are performed by the magnetic head. It is possible to suppress an increase in the drive torque of the disk medium.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of a servo write system using a plurality of servo writers according to an embodiment of the present invention.

FIG. 2 is a front view corresponding to FIG.

FIG. 3 is a plan view showing a detailed configuration of the servo writer 10;

FIG. 4 is a front view showing a detailed configuration of a mounting table 11 in the servo writer 10;

FIG. 5 is a diagram showing positioning of the transfer robot 31.

FIG. 6 is a perspective view showing a driving state of a magnetic disk cartridge according to one embodiment and a cleaning member.

FIG. 7 is a plan view showing a cleaning member according to another embodiment.

[Explanation of symbols]

 Reference Signs List 1 magnetic disk cartridge 3 magnetic disk medium 4 shutter 5 magnetic head insertion opening 6 hub 10 servo writer 11 mounting table 11a receiving surface 11b inclined guide surface 12 holding table 13 spindle 15 magnetic head for servo write 16 suspension member 31 transport robot 32 supply station 33 Normal Product Accumulation Station 34 Defective Product Accumulation Station 43 Suction Cup 44 Transfer Robot Rotation Mechanism 45 Transport Robot Elevation Mechanism 46 Transport Robot Travel Mechanism 51 Rotary Body of Each Station 53 Rotation Mechanism of Each Station 54 Elevation Mechanism of Each Station 60 Magnetic Plate-shaped base member 61 of head 15 Cleaning member mounting portion 62 Cleaning surface 66 Cleaning member θ Bias angle

Claims (1)

[Claims] A servo writer for a magnetic disk cartridge for writing a servo signal for positioning a head to a magnetic disk cartridge rotatably housed in a case of a disk-shaped high-density magnetic disk medium. A servo head, wherein a cleaning member is provided adjacent to at least a side edge of the magnetic head on the upstream side with respect to the rotation direction of the magnetic disk medium when the magnetic disk medium rotates. Writer.