JP2007133974A - Servo writer and its writing method, and disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reject the disks recorded with abnormal servo signals without fail. <P>SOLUTION: Two magnetic heads 5 are attached on the tip end of the suspension arm 6. Each of the upper head sensor 31 and the lower head sensor 32 has a light emitting element and a photodetector and is connected to a controller 7. Each of the sensors 31 and 32 sends the received light volume signals showing the amount of the light reflected on the magnetic head 5 and received by the photodetector to the controller 7 while writing servo signals. The controller 7 calculates the height, the up-and-down moving range, and the frequency of changes of the magnetic head 5 based on the input received light volume signals. A discriminator 7b determines whether or not the calculation results are within the range set in advance. When it decides that the calculation results are within the limit, the controller 7 continues its servo writing. However, when the calculation results are decided to be out of the range by the discriminator 7b, the controller 7 controls the drive of the magnetic head 5 to stop the servo writing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a servo writer and method for recording a servo signal on a flexible magnetic disk, and a disk.

  A servo signal for controlling the position of the recording / reproducing head of the disk drive device is recorded on the flexible magnetic disk loaded in the disk drive device. This servo signal is recorded by a servo writer. The servo writer includes a spindle motor and a write head (the magnetic head of the present case), rotates the flexible magnetic disk with the spindle motor, and records servo signals on the rotated flexible magnetic disk with the magnetic head.

When dust adheres to the flexible magnetic disk, there is a problem that the servo signal cannot be normally recorded by the magnetic head. Therefore, the servo track writer disclosed in Patent Document 1 includes a first head unit for recording a servo signal and a second head unit for reproducing the servo signal, and the servo signal is recorded on the disk by the first head unit. The servo signal recorded on the disk is reproduced by the second head unit, and it is determined whether the reproduced servo signal is a normal servo signal. If the reproduced servo signal is an abnormal servo signal, the fact is output as an image or sound so that the operator can understand it.
JP 2002-93087 A

  However, in the above-mentioned Patent Document 1, when the reproduced servo signal is an abnormal servo signal, the fact is output as an image or sound so that the operator can recognize it. However, there is no statement about how to process the disk on which the servo is recorded, and there is a problem that the disk on which the abnormal servo signal is recorded cannot be reduced.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a servo writer and method that can surely reduce the number of disks on which abnormal servo signals are recorded, and a disk.

  In order to achieve the above object, a servo writer according to the present invention includes a spindle motor that rotates a disk; and a magnetic head that records and reads a servo signal on the disk rotated by the spindle motor. A head sensor for detecting the height position of the magnetic head; and determining whether the height position of the magnetic head is within a preset height position range based on the detection result of the head sensor. A height determination unit; a stop control unit that stops recording of a servo signal by the magnetic head when the determination unit determines that it is not within the set height position range; and after a stop control by the stop control unit The output level of the servo signal recorded on the disk and read by the magnetic head is set to a preset output level range. Output level determination means for determining whether or not the output level is within the set output level range by the output level determination means; and restart control means for restarting recording of the servo signal by the magnetic head. It is characterized by that. Examples of the disk include a flexible magnetic disk and a hard disk. The head sensor is preferably a non-contact type sensor, and examples thereof include a laser displacement sensor, an eddy current displacement sensor, and a capacitance displacement sensor.

  It is preferable that the apparatus further comprises signal erasing means for erasing a servo signal recorded on the disk when the output level determining means determines that the output level is not within the set output level range.

  Further, the servo write method of the present invention detects the height position of the magnetic head in the servo write method in which a servo signal is recorded on the rotated disk by a magnetic head. Based on whether the height position of the magnetic head is within a preset set height position range, and when it is determined that the magnetic head is not within the set height position range, Stop recording, and after the servo signal recording by the magnetic head is stopped, determine whether the output level of the servo signal recorded on the disk and read by the magnetic head is within a preset set output level range. The recording of the servo signal by the magnetic head is resumed when it is determined that it is within the set output level range.

  The disc of the present invention is characterized in that servo signals are recorded by the servo writer described above.

  According to the servo writer of the present invention, a spindle motor that rotates the disk; a magnetic head that records and reads servo signals on the disk rotated by the spindle motor; a head sensor that detects the height position of the magnetic head; Height determining means for determining whether or not the height position of the magnetic head is within a preset height position range based on the detection result of the head sensor; and not within the set height position range by the determining means Stop control means for stopping the recording of the servo signal by the magnetic head when it is determined that; after the stop control by the stop control means, the output level of the servo signal recorded on the disk and read by the magnetic head is preset. Output level determining means for determining whether the output level is within the set output level range; determined by the output level determining means to be within the set output level range And a resumption control means for resuming servo signal recording by the magnetic head, so that dust adheres to the disk surface, an abnormality occurs in the behavior of the magnetic head, and the servo signal may not be recorded normally. If there is a possibility, it is possible to prevent the generation of defective products by immediately stopping the servo write. Further, when the output level determination means determines that the output level is within the set output level range, the servo signal recording is resumed by the magnetic head, so that the waste of discarding the disk on which the servo signal is normally recorded is eliminated. Can do.

  In addition, since the output level determining means includes signal erasing means for erasing the servo signal recorded on the disk when it is determined that the output level is not within the set output level range, the disk on which the abnormal servo signal is recorded is provided. Recording of servo signals can be eliminated, thereby increasing the number of disks manufactured per hour and increasing the number of disks that can be servo-written by one magnetic head. Can do.

  Further, according to the servo write method of the present invention, the height position of the magnetic head is detected in the servo write method in which the disk is rotated and the servo signal is recorded on the rotated disk by the magnetic head. Based on this, it is determined whether or not the height position of the magnetic head is within a preset height position range. When it is determined that the magnetic head is not within the set height position range, servo signal recording by the magnetic head is stopped. After the servo signal recording by the magnetic head is stopped, it is determined whether the output level of the servo signal recorded on the disk and read by the magnetic head is within a preset output level range. When it is determined that the servo head recording is resumed, the magnetic head behavior is abnormal and the servo signal is not recorded normally. If there is a possibility immediately by stopping the servo writing, it is possible to prevent the occurrence of defective products.

  Further, according to the disk of the present invention, since the servo signal is recorded by the servo writer described above, it is possible to reduce defective products due to the occurrence of an abnormality in the behavior of the magnetic head, and to reduce the cost per sheet. Can be lowered.

  As shown in FIGS. 1, 2 and 3, a servo writer 2 embodying the present invention records a servo signal on a flexible magnetic disk (disk) 3, and a spindle motor 4 and a magnetic head 5 are provided at the tip portion. A suspension arm 6, a control unit 7, and a disk holding case 8 attached to the vehicle. The disk holding case 8 is movable by a case moving mechanism 9 between a holding position (see FIG. 3) for holding the flexible magnetic disk 3 and a retracted position (see FIGS. 1 and 2) retracted from the holding position. Is provided. The case moving mechanism 9 is connected to the control unit 7, and the drive is controlled by the control unit 7. The control unit 7 is provided with a memory 7a that stores various data, which will be described in detail later, and a determination unit 7b as a height determination unit and an output level determination unit. The memory 7a stores a calculation program for calculating the height position of the magnetic head 5, which will be described later, the amplitude value in the vertical direction, and the fluctuation frequency.

  The flexible magnetic disk 3 is coated with a magnetic layer on both sides, and a disk hole 3a is formed at the center. A metal center core 15 is attached to the center of the lower surface of the flexible magnetic disk 3 with a double-sided tape or the like. The center core 15 is formed in a disc shape, an insertion hole 15a is formed in the center portion, and a ring-shaped engagement convex portion for engaging with the spindle head 27 is formed on the lower surface.

  The magnetic head 5 is for recording, reading and erasing servo signals on the flexible magnetic disk 3, and is attached to the tip of the suspension arm 6. The magnetic head 5 includes a head body, and the head body is composed of a recording element that converts an electrical signal corresponding to data to be recorded on the flexible magnetic disk 3 into a magnetic field. The magnetic head 5 is connected to the control unit 7 by a connection wire (not shown), and the drive is controlled by the control unit 7 to record a servo signal on the flexible magnetic disk 3.

  The suspension arm 6 includes an upper load beam 17 and a lower load beam 18 made of a thin metal that can be elastically deformed. The upper load beam 17 and the lower load beam 18 are rotatably attached to a motor shaft 19a of a load motor 19 composed of a VCM (voice coil motor). As the load motor 19 is driven, the upper load beam 17 and the lower load beam 18 rotate. The magnetic head 5 is attached to the lower end portion of the upper load beam 17 and the upper end portion of the lower load beam 18. When the suspension arm 6 is rotated, it is arranged so that the flexible magnetic disk 3 is sandwiched by a mechanism in which the flexible magnetic disk 3 enters between the upper load beam 17 and the lower load beam 18. As a result, servo signals can be recorded on the upper and lower surfaces of the flexible magnetic disk 3. The load motor 19 is connected to the control unit 7, and the drive is controlled by the control unit 7. The load motor 19 is fixed to a base plate (not shown) to which the spindle motor 4 is fixed.

  The magnetic head 5 is always biased in a direction to be pressed against the flexible magnetic disk 3 by a constant force by the upper load beam 17 and the lower load beam 18 that are elastically deformed.

  The disk holding case 8 is for holding the upper and lower surfaces of the flexible magnetic disk 3 and has a concave disk insertion portion 8a into which the flexible magnetic disk 3 is inserted. In this disk insertion portion 8 a, the entrance when the flexible magnetic disk 3 is inserted is formed in a tapered shape as a guide for the flexible magnetic disk 3.

  Liners (not shown) for removing dust on the surface of the flexible magnetic disk 3 and preventing it from being damaged are attached to the upper and lower surfaces of the disk insertion portion 8a. The disc holding case 8 is formed with a notch 8b for allowing the suspension arm 6 to move and for allowing the center core 15 and the spindle head 27 to rotate.

  When the disk holding case 8 is moved from the retracted position to the holding position, the disk is damaged even when the flexible magnetic disk 3 is stopped or the flexible magnetic disk 3 and the disk holding case 8 come into contact with each other. It is set to move in a state of being rotated at a difficult low speed (for example, 300 rpm or less). In the present embodiment, the disk holding case 8 is moved from the retracted position to the holding position while the flexible magnetic disk 3 is rotated at 200 rpm.

  The spindle motor 4 is for rotating the flexible magnetic disk 3 and includes a motor main body 26 and a spindle head 27. The motor body 26 is connected to the control unit 7, and the drive is controlled by the control unit 7. When the motor body 26 is driven, the spindle head 27 rotates. The spindle motor 4 is fixed to a base plate (not shown).

  The spindle head 27 is formed in a columnar shape, and an engagement recess 27 a into which the engagement protrusion of the center core 15 of the first flexible magnetic disk 3 is inserted is formed on the upper surface. Three magnets are embedded in the spindle head 27 at a pitch of 120 °, and the engaging convex portion of the center core 15 is inserted into the engaging concave portion 27a to engage the center core 15 and the spindle head 27. When the positioning is performed (hereinafter, the flexible magnetic disk 3 is referred to as a set on the spindle head 27), the metal center core 15 is held by the magnetism. The number of magnets embedded in the spindle head 27 can be changed as appropriate, and magnets configured in a ring shape may be used.

  When performing servo writing (servo signal recording) on the flexible magnetic disk 3, the controller 7 controls driving of the motor body 26 so as to rotate the flexible magnetic disk 3 at 3600 rpm.

  As shown in FIG. 3, the servo writer 2 is provided with an upper head sensor 31 and a lower head sensor 32. The upper head sensor is for detecting the height position of the upper magnetic head 5 of the two magnetic heads 5, and the lower head sensor 32 is for detecting the height position of the lower magnetic head 5. Is for.

  The upper head sensor 31 is composed of a non-contact type laser displacement sensor having a light emitting element and a light receiving element (CCD or the like). The upper head sensor 31 is connected to the control unit 7, and the drive is controlled by the control unit 7. The upper head sensor 31 receives the reflected light emitted from the light emitting element and reflected by the magnetic head 5 by the light receiving element, and sends a received light amount signal indicating the amount of received light to the control unit 7.

  The lower head sensor 32 is composed of a non-contact type laser displacement sensor having a light emitting element and a light receiving element (CCD or the like). The lower head sensor 32 is connected to the control unit 7, and the drive is controlled by the control unit 7. The lower head sensor 32 receives the reflected light emitted from the light emitting element and reflected by the magnetic head 5 by the light receiving element, and sends a received light amount signal indicating the amount of the received light to the control unit 7.

  When the flexible magnetic disk 3 is set on the spindle head 27, the control unit 7 starts servo writing after moving the disk holding case 8 from the retracted position to the holding position. When servo writing is started, the control unit 7 drives the head sensors 31 and 32. When the head sensors 31 and 32 are driven, a received light amount signal indicating the amount of light reflected by the magnetic head 5 and received by the light receiving element is input to the control unit 7. When the received light amount signal is input, the control unit 7 activates a calculation program stored in the memory 7a, and based on the input received light amount signal, the height position of the magnetic head 5, the vertical amplitude value, and the fluctuation. The frequency is calculated. Then, the determination unit 7b of the control unit 7 refers to the memory 7a to determine whether or not the calculation result is within a preset setting range. For this reason, the memory 7a stores data of setting ranges for the height position of the magnetic head 5, the amplitude value in the vertical direction, and the frequency of fluctuation. The calculation of the height position of the magnetic head 5, the amplitude value in the vertical direction, the fluctuation frequency, and the determination as to whether the calculation result is within the set range are repeated during servo writing. The set range described above indicates a numerical range within which the magnetic head 5 determines that the servo signal is normally recorded on the flexible magnetic disk 3.

  When the determination unit 7b determines that the calculation result is within the specified range, the control unit 7 continues the servo write.

  On the other hand, when the determination unit 7b determines that the calculation result is not within the specified range, the control unit 7 controls the drive of the magnetic head 5 and stops the servo write (servo signal recording). In the present embodiment, the control unit 7 also functions as a stop control unit that stops the recording of the servo signal by the magnetic head 5 when the determination unit 7b determines that the calculation result is not within the specified range.

  Next, after the servo signal recording is stopped, the control unit 7 controls the driving of the magnetic head 5 and reads the servo signal recorded on the flexible magnetic disk 3. The read signal thus read is input to the control unit 7. Then, the determination unit 7b determines whether or not the output level of the read signal is within a preset output level range. For this reason, the memory 7a stores data of the set output level range of the read signal. When the determination unit 7b determines that the output level of the read signal is within the set output level range, the control unit 7 controls the drive of the magnetic head 5 and resumes servo writing. The determination of whether or not the output level of the read signal is within the set output level range is repeatedly performed when the determination unit 7b determines that the calculation result is not within the set range during servo writing. . The set output level range described above indicates a numerical range within which it is determined that a normal servo signal is recorded on the flexible magnetic disk 3. In the present embodiment, the control unit 7 also serves as a restart control unit that resumes recording of the servo signal by the magnetic head 5 when the determination unit 7b determines that the output level of the read signal is within the set output level range. Function.

  On the other hand, if the determination unit 7b determines that the output level of the read signal is not within the set output level range, the control unit 7 controls the drive of the magnetic head 5 and the servo recorded on the flexible magnetic disk 3. Clear the signal. In the present embodiment, the magnetic head 5 also functions as a signal erasing unit that erases the servo signal recorded on the flexible magnetic disk 3.

  The operation of the servo writer 2 configured as described above will be described with reference to the flowchart of FIG. When the flexible magnetic disk 3 is set on the spindle head 27 (step (hereinafter, S) 1), the control unit 7 moves the disk holding case 8 from the retracted position to the holding position (S2), and then starts servo writing. (S3). When the servo light is started, the control unit 7 drives the upper head sensor 31 and the lower head sensor 32 (S4).

  When the head sensors 31 and 32 are driven, a received light amount signal indicating the amount of light reflected by the magnetic head 5 and received by the light receiving element is input to the control unit 7. The control unit 7 calculates the height position, the vertical amplitude value, and the fluctuation frequency of the magnetic head 5 based on the received light amount signal (S5). Then, the determination unit 7b of the control unit 7 refers to the memory 7a to determine whether or not the calculation result is within a preset setting range (S6). When it is determined that the calculation result is within a preset setting range, the control unit 7 continues servo writing by the magnetic head 5 (S7). Next, the control unit 7 determines whether or not the servo write has ended (S8), and if it is determined that the servo write has not ended, the control unit 7 determines that the height position of the magnetic head 5 is Then, the vertical amplitude value and the fluctuation frequency are calculated (S5).

  On the other hand, when the determination unit 7b determines that the calculation result is not within the preset setting range, the control unit 7 controls the drive of the magnetic head 5 and stops the servo write (S9). ). Next, the controller 7 controls the drive of the magnetic head 5 and reads the servo signal recorded on the flexible magnetic disk 3 (S10). Then, the determination unit 7b determines whether or not the output level of the read signal is within the set output level range (S11). When the determination unit 7b determines that the output level of the read signal is within the set output level range, the control unit 7 controls the drive of the magnetic head 5 and resumes servo writing (S12). Next, the control unit 7 determines whether or not the servo write has ended (S8), and if it is determined that the servo write has not ended, the control unit 7 determines that the height position of the magnetic head 5 is Then, the vertical amplitude value and the fluctuation frequency are calculated (S5).

  On the other hand, when the determination unit 7 b determines that the output level of the read signal is not within the set output level range, the control unit 7 controls the drive of the magnetic head 5 and records it on the flexible magnetic disk 3. The servo signal is erased (S13).

  As a process after erasing the servo signal recorded on the flexible magnetic disk 3, the drive of the magnetic head 5 is controlled again to record the servo signal on the flexible magnetic disk 3. The flexible magnetic disk 3 is recorded on the servo writer 2. The process is transferred to an appropriate process, such as removing the servo signal and recording a servo signal with another servo writer. If the determination unit 7b determines that the output level of the read signal is not within the set output level range when the servo signal is recorded again regardless of the same servo writer 2 or another servo writer. Since there is a high possibility that the flexible magnetic disk 3 itself has a defect (for example, large surface shake), it is preferable to immediately discard the flexible magnetic disk 3.

  As described above, during the servo write, the height position of the magnetic head 5, the vertical amplitude value, and the fluctuation frequency are calculated, and if it is determined that the calculation result is not within the set range, the control unit 7 is a case where the servo write is stopped, so that an abnormality occurs in the behavior of the magnetic head 5 (for example, when a foreign matter adheres to the disk surface) and the servo signal may not be recorded normally. Can immediately stop the servo write to prevent the generation of defective products. Further, when it is determined that the above calculation result is not within the set range, the servo signal recorded on the flexible magnetic disk 3 is read and it is determined that the output level of the read signal is within the set output level range. In this case, since the servo write is resumed, it is possible to eliminate the waste of discarding the flexible magnetic disk 3 on which the servo signal is normally recorded.

  Further, when it is determined that the output level of the read signal is not within the set output level range, the control unit 7 erases the servo signal recorded on the flexible magnetic disk 3, so that an abnormal servo signal is recorded. It is possible to eliminate the waste of recording servo signals to the end of the flexible magnetic disk 3 (defective product as a product), thereby increasing the production quantity of the flexible magnetic disk 3 per hour and The number of flexible magnetic disks 3 that can be servo-written by the magnetic head 5 can be increased.

  In the above embodiment, the present invention is applied to the servo writer 2 that records a servo signal on one flexible magnetic disk 3, but it is also applied to a servo writer that simultaneously records servo signals on a plurality of flexible magnetic disks 3. In this case, the suspension arm 6, the disk holding case 8, the upper head sensor 31, and the lower head sensor 32 are provided as many as the number of the flexible magnetic disks 3. In a servo writer that simultaneously records servo signals on a plurality of flexible magnetic disks 3, a spacer is preferably disposed between each of the plurality of flexible magnetic disks 3.

  Moreover, in the said embodiment, although the upper head sensor 31 and the lower head sensor 32 were comprised from the laser displacement sensor, it is not limited to this, What is necessary is just a non-contact type sensor, for example, an eddy current type displacement You may make it comprise a sensor, an electrostatic capacitance displacement sensor, etc.

It is a perspective view which shows the servo writer which implemented this invention. It is a side view which shows a servo writer when a disk holding case is located in a retracted position. It is a side sectional view showing a flexible magnetic disk, a spindle motor, a magnetic head, a suspension arm, a disk holding case, a load motor, an upper head sensor, and a lower head sensor when the disk holding case is located at the holding position. It is a flowchart which shows the flow of a process of recording of the servo signal in a servo writer, determination of head height, and determination of the recorded servo signal.

Explanation of symbols

2 Servo writer 3 Flexible magnetic disk (disk)
4 Spindle motor 5 Magnetic head 6 Suspension arm 7 Control unit 7a Memory 7b Determination unit 15 Center core 19 Load motor 31 Upper head sensor 32 Lower head sensor

Claims (4)

A spindle motor that rotates the disk;
In a servo writer having a magnetic head for recording and reading servo signals on the disk rotated by the spindle motor,
A head sensor for detecting a height position of the magnetic head;
Height determining means for determining whether the height position of the magnetic head is within a preset height position range based on the detection result of the head sensor;
Stop control means for stopping servo signal recording by the magnetic head when the determination means determines that the position is not within the set height position range;
Output level determination means for determining whether the output level of the servo signal recorded on the disk and read by the magnetic head after the stop control by the stop control means is within a preset set output level range;
A servo writer comprising: restart control means for restarting recording of a servo signal by the magnetic head when the output level determination means determines that the output level is within the set output level range.   2. The servo writer according to claim 1, further comprising a signal erasing unit for erasing a servo signal recorded on the disk when the output level determining unit determines that the output level is not within the set output level range. . Rotate the disc
In a servo write method for recording a servo signal on the rotated disk by a magnetic head,
Detecting the height position of the magnetic head, and determining whether the height position of the magnetic head is within a preset height position range based on the detection result;
When it is determined that it is not within the set height position range, recording of the servo signal by the magnetic head is stopped,
After the servo signal recording by the magnetic head is stopped, it is determined whether the output level of the servo signal recorded on the disk and read by the magnetic head is within a preset output level range,
A servo write method, comprising: resuming servo signal recording by the magnetic head when it is determined that the output level is within the set output level range.   A disk on which a servo signal is recorded by the servo writer according to claim 1.

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