JP2002083462A - Magnetic recording/reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that the position variation of a sector due to the rotation variation of a spindle motor occurs, a track gap is necessary for initialization, and the position of a sector cannot precisely be detected by measuring time measurement from the index. SOLUTION: This magnetic recording/reproducing device to record and reproduce fixed-length data is provided with a medium fixing means (chucking mechanism 40) which attaches a magnetic recording medium at the same angle to the rotor 39 of the spindle motor 38 to rotationally drive a disk-shaped magnetic recording medium 22, and a starting point detecting means (index detector 41) which determines the, starting point and the end point of data tracks. A divided signal generating means 303 which generates a divided signal to divide one rotation into a plurality of parts by detecting the rotation angle of the rotor of the spindle motor on the basis of the starting point of rotation determined by the starting point detecting means is provided, and a reference position on the data tracks is determined by using the divided signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus for recording / reproducing information, such as a flexible magnetic disk apparatus.

[0002]

2. Description of the Related Art FIG. 21 shows a servo format of a flexible magnetic disk device as a conventional magnetic recording / reproducing device shown in, for example, MR88-56 of the Magnetic Recording Research Society of the Institute of Electronics, Information and Communication Engineers.
Reference numerals 3, 14, 15, 16, 17, and 18 denote servo burst patterns, 19 denotes a data track, 20 denotes one data track pitch, 21 denotes a half data track pitch, and 42 denotes a magnetic head for writing and reading data on a magnetic recording medium. It is.

FIG. 22 is a configuration diagram of a conventional flexible disk device shown in, for example, “Newest Floppy Disk Device and Its Application Know-how”, page 24, published by Shoji Takahashi, published by CQ Publishing Company. 38 is a spindle motor, 39 is a rotor, 40 is a chucking mechanism,
1 is an index detector, 42 is a magnetic head.

FIGS. 23 and 24 show, for example, “JIS Handbook Information Processing Hardware” edited by the Japan Standards Association.
FIG. 61 is a diagram showing a generation position of an index signal shown on page 61 and a data track format of a flexible disk device. In the figure, 19 is a data track, 44 is a sector, 45 is an index gap, 46 is a sector identifier, 47 is an identifier gap, 48 is a data block,
9 is a data block gap, 50 is a track gap, 96 is an index position, 97 is an index signal,
05 is a line segment in the radial direction.

FIGS. 25, 26 and 27 are developed views of a motor disclosed in Japanese Patent Publication No. 2-55870, for example.
In the figure, 39 is a rotor, 51 is a permanent magnet, 52 is a rotating shaft, 53 is a bearing holder, 54a and 54b are bearings, 55 is a printed circuit board, 56 is a through hole, 57 is an excitation phase detection pattern,
58 is a rotation number detection pattern, 59a and 59b are optical detectors, 74 is a crystal oscillator, 66 to 70 are transistors, 6
Numerals 0 to 65 are driving coils, 71 to 73 are integrated circuits (hereinafter referred to as ICs), and 111 and 112 are LEDs.

FIG. 29 shows, for example, "Nikkei Electronics 1987.2.9. (No. 414)" (Nikkei B
FIG. 6 is a simplified system diagram of a conventional magnetic disk drive described in FIG. In FIG. 29, reference numeral 80 denotes a recording / reproducing circuit, 81 denotes a disk controller, 82 denotes a clock oscillation circuit, and 83 denotes a host-side microprocessor.

Next, the servo format will be described with reference to FIG. The tracking to the data track 19 is performed by calculating an appropriate tracking error signal from the amplitude value of the read signal of the servo pattern 12. The amplitude value of the read signal corresponds to the servo burst patterns 13, 14, 15, 16, 17, 18 and the magnetic head 42 for writing and reading data.
Is almost proportional to the overlapping area.

Next, the procedure for recording this servo format will be described. First, the magnetic head 4 has a half data track pitch 21 which is half the data track pitch.
2 is step-moved in the radial direction, and the servo pattern area of the magnetic recording medium is DC-erased over all data tracks. Next, the servo burst patterns 13 and 14 are written over all the data tracks while step-moving by one data track pitch 20 at a time. Servo burst pattern 13,
14, 15, 16, 17 and 18 are generally continuous magnetization reversals and are recorded at specific magnetization reversal intervals so as to be detectable. Finally, the servo burst patterns 15, 16, 17, and 18 are written over all the data tracks 19 while the magnetic head 42 follows the data tracks 19 using the servo burst patterns 13 and 14.

The servo burst patterns 13 and 14 are mainly used for generating a tracking error signal. Servo burst pattern 1
5, 16, 17, and 18 are mainly used for identifying the data track 19. Thus, the servo pattern is used for generating a tracking error signal and identifying the data track 19. Since the tracking error signal corresponds to the difference between the amplitude values of the read signals of the servo burst pattern 13 and the servo burst pattern 14, the magnetic head 42 controls the servo burst pattern 1
Positioning is made such that the same area is overlapped with 3, 14.
Since the servo burst patterns 13 and 14 are recorded by using the magnetic head 42 used when recording data, the data tracks 19 between the servo burst patterns 13 and 14 are recorded.
There is as much spacing as between Therefore, the amplitude value of the read signal of the servo burst patterns 13 and 14 when correctly following the data track 19 is の of the maximum value.
Less than.

Next, the operation of recording / reproducing the format and data on the magnetic recording medium and detecting the servo pattern will be described with reference to FIGS. 22 and 23. Magnetic recording medium 2
2 is a radial line segment determined by the shape of the magnetic recording medium.
Numeral 05 is fixed by the chucking mechanism 40 at a position which always makes a fixed angle with respect to the rotor 39 of the spindle motor 38. The spindle motor 38 is connected to the magnetic recording medium 22.
Is rotated at a constant angular velocity. Although not shown in the drawing, an index is attached to the rotor 39. The index detector 5 is adjusted to generate an index signal 97 within a specified time after the recording / reproducing magnetic head 42 has passed over the line segment 105. Therefore, the index position 96 is always a fixed position on the magnetic recording medium 22.

In a flexible magnetic disk drive, concentric data tracks 19 are formed on a magnetic recording medium 22. Sectors 44 (see FIG. 24) are arranged on the data track 19, and data is recorded and reproduced in sector units. The arrangement of each sector 44 is set at the time of formatting. After rotating the magnetic recording medium 22 at a constant speed and detecting an index signal, an index gap 45 (FIG.
4), and the sectors 44 are sequentially set. The sector 44 includes a sector identifier 46, an identifier gap 47, a data block 48, and a data block gap 49, and records an identifier unique to the sector at the time of formatting. After writing the predetermined number of sectors 44,
The track gap 50 (see FIG. 24) occurs until the index signal is detected again.

At the time of recording / reproducing, after positioning is performed on a target data track, the sector position is detected by reproducing the sector identifier 46 recorded at the time of formatting.

Next, the operation of writing data to the flexible magnetic disk device will be described with reference to FIG. Write data is sent from the microprocessor on the host side to the flexible magnetic disk device at the data transfer rate F ′ [bit / s]. Then, the disk controller 81 temporarily stores this data in the buffer and sends the data transfer speed F0 [bi
[t / s]. Generally, the data rates F 'and F0 are not equal. The data transfer rate F 'is generally determined by the host-side microprocessor 83, but the data transfer rate F0 is generally determined by the clock oscillation circuit 82. In this description, for the sake of simplicity, when the frequency of the clock oscillation circuit 82 is F0, the data transfer speed that the disk controller 81 sends to the recording / reproduction circuit 80 is F
Let it be 0.

Next, a track gap required at the time of formatting will be described with reference to FIG. When formatting the data track 19, only one index position can be detected on the magnetic recording medium. Therefore, the data track 19 is continuously detected during one round from the detection of the index signal to the detection of the next index signal. Must be written. In the case of a fixed-length sector, since the length of the sector 44 is fixed, the starting position of each sector is fixed on the magnetic recording medium. When the rotational angular velocity of the spindle motor is constant, the time of each sector is also fixed. ing. Therefore, at the time of formatting, the sector identifier 46 indicating the beginning of the sector may be written at each time interval of each sector. However, in reality, since there is a rotation fluctuation of the spindle motor 38, a redundant area for absorbing the fluctuation is provided. Will be needed.
Therefore, during the data track format, rotation fluctuations for one rotation must be taken into consideration.
At the end of the area, the area where the rotation fluctuation is absorbed
It is set as 0.

This will be described in more detail. Now, it is assumed that all m sectors have the same length. It is assumed that the spindle motor 38 is rotating at a specified rotational angular speed w0 [rad / s]. When information for identifying the start of a sector is written for each t0 [s], m · t0 · w0 = 2π [ra
In d], the sectors are distributed at equal central angles.

However, the spindle motor generally has rotation fluctuation. It is assumed that the width of the rotation fluctuation of the spindle motor 38 is w1 <w0 <w2. In the case of the rotational angular velocity w2, the sector cannot be completely written, and formatting cannot be performed. Therefore, in consideration of the rotation fluctuation, it is necessary to write information for identifying the start of the sector at every time t2 corresponding to the highest rotation angular velocity. Where t2 is
m · t2 · w2 = 2π [rad] is satisfied. When writing the information for identifying the start of the sector at the time t2, if the rotational angular velocity is w1, a redundant area is formed at the end of the data track 19. This is the track gap 50.

Next, the data block gap 49 required when writing data will be described. Since the position of the sector set at the time of track formatting is fixed until the time of reformatting, it is necessary to set an area data block gap 49 in each sector 44 set at the time of formatting to absorb rotation fluctuation at the time of data recording.

This will be described in more detail. That is, how the recording area expands and contracts due to the rotation fluctuation of the spindle motor 38 will be described with reference to FIG. FIG.
FIG. 30 is a diagram schematically showing the data track 19, and FIG.
FIG. 3 is a diagram showing a typical example of rotation fluctuation of the spindle motor 38. In FIG. 31, reference numeral 84 denotes K [bit / s].
This is a recording area on the magnetic recording medium 22 when the data of (1) is recorded. In the figure, the data track is actually a circle in the flexible magnetic disk drive, but here it is approximated by a straight line for simplicity. In FIG. 30, the horizontal axis represents the rotation angle of the spindle, and the vertical axis represents the rotation angular velocity.

In FIG. 31, the prescribed rotational angular velocity of the spindle motor 38 is w0 [rad / s], the actual rotational angular velocity is w [rad / s], and the distance of the magnetic head 42 from the rotational center of the spindle motor 38 is R. [M]. The data transfer rate at which the disk controller 81 sends data to the recording / reproducing circuit is F0 [bit / s].

Now, when the spindle motor rotates at a specified angular velocity w0, and K (bit) data is to be recorded, the time t required for recording is t = K /
F0 [s]. Also, since the relative speed v between the magnetic head 42 and the magnetic recording medium 22 is v = R · w0 [m / s], the recording area L0 on the magnetic recording medium is L0 = v · t = K
R · w0 / F0 [m] ((a) of FIG. 31).

However, as shown in FIG. 30, a spindle motor generally has a rotation fluctuation. Even if an attempt is made to control the rotational angular velocity to w0, an error occurs in the rotational angular velocity depending on the rotational angle. Rotational angular velocity is w (not equal to w0)
When the length L on the magnetic recording medium is calculated in the same manner, L = K · R · w / F0. Therefore, w> w0
In this case, recording is performed longer than the specified recording area L0. The rotation fluctuation of the spindle motor is ± A [%],
That is, w0 · (1-A / 100) <w <w0 · (1
+ A / 100), the range of the length L of the recording area 84 on the magnetic recording medium 22 is L0 · (1−A / 10).
0) <L <L0 · (1 + A / 100), and K [bi
t] When recording, it is necessary to allow for this maximum value. In the current standard, the format is determined in consideration of these facts, and therefore a redundant area such as the data block gap 49 exists ((b) and (c) in FIG. 31).

Next, the configuration of the spindle motor 38 will be described with reference to FIGS. 25, 26 and 27. The rotor 39 is formed in a flat cylindrical shape and has permanent magnets 51 fixed therein at equal angular intervals as shown in FIG. The rotator 39 includes the chucking mechanism 40 and a rotating shaft 52.
Has been fixed. The rotating shaft 52 is rotatably supported by two upper and lower bearings 54a and 54b fixed to a bearing holder 53.

On the printed circuit board 55, a bearing holder 53 is provided.
The six driving coils 60 to
65 are provided, and these driving coils 60 to 6 are provided.
The rotor 39 is rotated by the magnetic flux obtained by passing a current through the magnet 5 for excitation and the permanent magnet 51.

The rotor 39 has an excitation phase detection pattern 57 in which a total of six black and white zones are alternately arranged at equal angular intervals and a rotation speed detection pattern 58 in which a total of 102 black and white zones are formed on a concentric circle. Is formed. The optical detectors 59a and 59 are provided on the printed circuit board 55 corresponding to these patterns.
9b is fixed. The optical detectors 59a and 59b are
Transistors 66 and 67 and LEDs 111 and 11 respectively
2 is comprised. The optical detector 59a detects the positional relationship between the driving coils 60 to 65 and the permanent magnet 51 from the excitation phase detection pattern 57. The optical detector 59b detects the pattern 58 and emits a pulse.

FIG. 26 shows a detection circuit using these optical detectors and driving coils. LED in the figure
111 and the transistor 66 make the optical detector 59a
D112 and the transistor 67 constitute the optical detector 59b. Rotation start signal MOT of spindle motor 38
By turning on, either the transistor 70 and the transistor 68 or the transistor 69 is turned on, and the driving coils 60, 62, 64 or the driving coils 61, 63, 6
5 flows.

The rotation of the rotor 39 is controlled by the optical detector 59.
a, 59b. The optical detector 59a comprising the LED 111 and the transistor 66 makes the pattern 57
Is detected, the output of transistor 66 becomes IC
71, and is input to the base of the transistor 68, and the transistor 68 is turned on and the driving coil 6 is turned on.
Current is supplied to 0,62,64. When white is detected, the output of the transistor 66 turns on the IC 71 and is input to the base of the transistor 69.
Are conducted, and current is supplied to the drive coils 61, 63, 65. At this time, the IC 72 is an inverter and the output is 0. The transistor 68 is turned off, and no current is supplied to the driving coils 60, 62, 64.

As described above, the transistor 68 and the transistor 69 are alternately switched according to the information detected by the optical detector 59a, and current is alternately applied to the driving coils 60, 62, 64 and the driving coils 61, 63, 65. It is configured to be excited.

The spindle motor 38 needs to keep rotating at a constant speed. For this purpose, servo control is performed using the IC 73. Transistor 70 includes driving coils 60 to 6
5 is used as a switch for adjusting the current flowing through the switch 5.
The IC 73 includes a reference signal from the crystal oscillator 74 and the LED 1
Optical detector 59b consisting of transistor 12 and transistor 67
Is compared with the detection result of the pattern 58, and if the rotation frequency calculated from the detection result is equal to or lower than the reference frequency, the base current of the transistor 70 is increased and the driving coil 60
The current flowing through # 65 is increased to increase the rotation speed. When the rotation frequency is equal to or higher than the reference frequency, the base current of the transistor 70 is reduced, and the driving coils 60 to
The number of revolutions is reduced by reducing the current flowing through the 65.

Another method of controlling the number of revolutions of the spindle motor 38 is to use the output of a frequency generator (hereinafter referred to as FG). FIG. 28 is a block diagram and operation waveforms of a constant speed control system using FG described in “Practical Motor Control Circuit Design Guide”, p. 194, published by Hiroshi Yamada, published by Sogo Denshi Shuppansha. In the figure, 98 is a frequency generator, 9
9 is a waveform shaping circuit, 100 is a differentiating circuit, 101 is a sawtooth wave generating circuit, 102 is a comparing circuit, 103 is an integrating circuit, and 104 is a driving circuit. In the figure, when the spindle motor 38 is rotating at a constant speed, the FG 98 generates an AC signal of several hundred hertz. An output to the spindle motor 38 is obtained by converting the FG output into a pulse width modulated wave corresponding to the speed, and smoothing it. The drive system controls the speed so as to reduce the ripple of the smoothed output.

[0030]

As described above, in the conventional flexible magnetic disk drive, a change in the position of the sector due to a change in the rotation of the spindle motor 38 appears, a track gap is required at the time of formatting, and the index from the index. There is a problem that the position of the sector cannot be accurately detected by measuring the time measurement.

Further, an identification signal for accurately detecting the position of a sector at the time of reproduction is required, and there has been a problem that an identification signal generation and a discrimination function for that purpose must be added to the recording / reproducing unit.

Further, there is a problem that a redundant area is also present due to rotation fluctuation when writing data.

The present invention has been made in order to solve the above-described problems, and has a function of detecting a plurality of positions on a magnetic recording medium without being affected by rotation fluctuation. It is an object of the present invention to provide a magnetic recording / reproducing apparatus which can be realized with a simple configuration without accompanying and can use a detected position on a magnetic recording medium as a reference point of a sector.

Also, a redundant area necessary for rotation fluctuation is eliminated, and the redundant area is used as a data recording area, or the data transfer speed at which a disk controller sends data to a recording / reproducing circuit is reduced to minimize the magnetic field. It is an object of the present invention to obtain a magnetic recording / reproducing apparatus which can be used to increase the reversal interval and improve performance.

[0035]

According to a first aspect of the present invention, there is provided a magnetic recording / reproducing apparatus in which a magnetic recording medium is mounted at the same angle with respect to a rotor of a spindle motor which rotationally drives a disk-shaped magnetic recording medium. A magnetic recording / reproducing apparatus which includes a medium fixing means (chucking mechanism 40) and a start point detecting means (index detector 41) for determining a start point and an end point of a data track, and records and reproduces fixed-length data. A divided signal generating means 303 for generating a divided signal for dividing one rotation into a plurality of parts with reference to a determined starting point of rotation by detecting a rotation angle of a rotor of a spindle motor is provided. It is characterized in that a reference position is determined. A magnetic recording / reproducing apparatus according to a second aspect of the present invention is characterized in that the magnetic recording / reproducing apparatus also serves as a split signal generating means and a rotor rotation angle detecting means for controlling a spindle motor. In the magnetic recording / reproducing apparatus according to the third aspect of the present invention, the rotational angular velocity detecting means 304 detects the rotational velocity of the rotor of the spindle motor.
And a divided signal generating means 303 for generating a divided signal using the output of the rotational angular velocity detecting means. A magnetic recording / reproducing apparatus according to a fourth aspect of the present invention is characterized in that an excitation phase switching signal of a driving coil of a spindle motor is used as the divided signal generating means 303. According to the magnetic recording / reproducing apparatus of the fifth aspect, the divided signal generating means 30
As a third feature, a magnetic field magnetized at a different portion or the same portion as the driving magnetic field generating portion of the rotor is detected by using a magnetic sensor arranged on a substrate to which the driving coil is fixed. Things. A magnetic recording / reproducing apparatus according to claim 6, wherein a servo signal is recorded in a part of a sector, and a positioning control of a magnetic head is performed on a data track using the servo signal. It is characterized in that sampling of a servo signal synchronized with rotation of the motor is performed. A magnetic recording / reproducing apparatus according to a seventh aspect of the present invention comprises a rotational angular velocity detecting means 304 for detecting a rotational angular velocity of a spindle motor, and a data write frequency for writing a constant amount of data at a constant angle using the rotational angular velocity. And a writing frequency adjusting means (for example, an oscillation circuit 89) for adjusting the frequency. In the magnetic recording / reproducing apparatus according to claim 8, the distance r from the rotation center of the spindle motor is:
If the rotation angle is a [rad], r = r0 + (r1-r
0) × (a / 2π) (where r0 and r1 are constants) and a length measuring device which is located outside the reflecting member and measures a distance to the reflecting member. 87 and a differentiation circuit 88 for differentiating the output of the length measuring device
And an oscillation circuit 89 for adjusting the oscillation frequency based on the value of the output voltage of the differentiating circuit. A magnetic recording / reproducing apparatus according to a ninth aspect of the present invention includes an encoder 93 for generating a pulse at each equal angle of the spindle motor, and a doubling circuit 94 for multiplying the frequency of the pulse generated by the encoder by n. It is characterized by the following.

[0036]

According to the first aspect of the present invention, the division signal generating means detects the rotation angle of the rotor of the spindle motor, based on the division signal for dividing one rotation into a plurality of rotations based on the start point of rotation determined by the start point detection means. To create. A reference position on the data track is determined using the divided signal.
According to the second aspect of the present invention, the divided signal generating means and the rotor rotation angle detecting means for controlling the spindle motor are also used. According to the third aspect of the present invention, the divided signal creating means creates a divided signal using the output of the rotational angular velocity detecting means. In the invention according to claim 4, an excitation phase switching signal of a driving coil of the spindle motor is used as the division signal generation means. According to the fifth aspect of the invention, a magnetic field magnetized at a different portion from or the same as that of the driving magnetic field generator of the rotor is detected by a magnetic sensor disposed on a substrate to which the driving coil is fixed. In the present invention, the sampling of the servo signal synchronized with the rotation of the spindle motor is performed by using the divided signal. In the present invention, the rotational angular velocity detecting means detects the rotational angular velocity of the spindle motor, and the write frequency adjusting means adjusts the data write frequency so as to write a constant amount of data at a constant angle using the rotational angular velocity. . In the invention of claim 8, the length measuring device measures the distance to the reflecting member, the differentiating circuit differentiates the output of the length measuring device, and the oscillation circuit adjusts the oscillation frequency based on the output voltage value of the differentiating circuit. In the ninth aspect of the present invention, the encoder generates a pulse at each equal angle of the spindle motor, and the multiplying circuit multiplies the frequency of the pulse generated by the encoder by n.

[0037]

[Embodiment 1] Hereinafter, a servo format according to an embodiment of the present invention will be described with reference to the drawings. This embodiment is for improving the reliability of the tracking error signal. In FIG. 1, 3 is the core width of the lower head 2 and 5 is the lower head 2
, A core width of a write head, 9 a core width of a read head, 11 a servo format, 12 a servo format, 13, 14, 15, and.
16, 17, and 18 are servo burst patterns, 19 is a data track, and 20 is a data track pitch.

FIG. 2 is a perspective view of one embodiment of the composite head according to the present invention. 1 is a composite head, 200 is an upper head, 2 is a lower head, 4 is a preceding erase head of the lower head 2, 6 is a write head that forms the upper head 200, 8 is a read head that forms the upper head 200, and 34 is a magnetic head. Is an insulating layer. The composite head 1 is formed on a rail on one side of a head slider (not shown). This composite head 1 is proposed by Masaru Okada of Mitsubishi Electric Corporation.

FIG. 3 is a configuration diagram of an embodiment of the flexible magnetic disk drive of the present invention. In the figure, 10 is an actuator, 22 is a magnetic recording medium, 23 is the outermost data track, 24 is the data track of cylinder number i, 25 is the innermost data track, 26 is the 0th servo pattern of the outermost track, and 27 is the outermost track. A servo pattern other than the 0th data track, 28 is a 0th servo pattern of the innermost data track, 29 is a servo pattern other than the 0th servo track of the innermost data track, and 30 is a servo pattern of the data track having the cylinder number i. FIGS. 4 and 5 are schematic diagrams for explaining the positioning function in this embodiment.
4 and 5, 132 is a guide rail, 133 is a yoke, 134 is a coil, 135 is an optical scale, 136.
Is a light emitting element, 137a and 137b are light receiving elements, and 138
Denotes a stator of a linear step motor, and 139 denotes a mover of the linear step motor. Yoke 133 and coil 1
34 and a magnet (not shown) attached to the inside of the yoke 133, and the linear step motor 1 from the stator 138 and the mover 139.
41.

The operation will be described with reference to FIGS. The actuator 10 has a function (coarse positioning means 10a) capable of positioning the composite head 1 at one data track pitch 20 according to an external scale (not shown) in order to record the servo format 11.
And a function (precision positioning means 10b) for positioning the composite head 1 with a resolution of 20 data track pitches or less in accordance with a tracking error signal generated from the two read signals. The actuator 10 can be realized by a step motor capable of stepping at one data track pitch 20 with a microstep function added thereto, or a voice drive coil motor having a scale of one data track pitch 20.

The core width 3 of the lower head 2 and the core width 5 of the lower preceding erase head 4 are equal to one data track pitch 2
Since it is wider than 0, it is sufficient to move the data track step by 20 at a data track pitch of 20 when DC erasing. Since the core width 3 of the lower head 2 is wider than one data track pitch 20, when the servo burst patterns 13 and 14 are recorded by using the lower head 2 while moving step by one data track pitch 20, a servo burst is generated at the center of the data track 19. The patterns 13 and 14 are recorded so as to slightly overlap each other. Finally, the servo burst patterns 15, 16, 17, and 18 are written using the write head 6 while the write head 6 and the read head 8 follow the servo burst patterns 13 and 14 using the actuator 10. Since the servo burst patterns 13 and 14 are recorded so as to slightly overlap with each other, the amplitude value of the read signal of the servo burst patterns 13 and 14 when correctly following becomes 1/2 or more of the maximum value. Furthermore, servo burst pattern 1
Even when the positioning accuracy when recording data 3 and 14 is somewhat poor, the width of the servo burst patterns 13 and 14 has a large influence on the signal amplitude at the time of reading. Burst pattern 1
The deterioration of the amplitude values of the read signals 3 and 14 is small. Therefore, the reliability of the tracking error signal is improved.

Further, since the width of the write head 6 is wider than the width of the read head 8, even if a tracking error occurs, the influence on the amplitude of the read signal is small, so that the reliability is further improved.

In the above description, the lower head 2 is used for recording the servo burst pattern. However, the same effect can be obtained by recording the servo burst pattern using the lower preceding erase head 4.

As a supplement, the above-described positioning function will be described with reference to FIGS. FIG. 4 is an explanatory diagram when a voice coil motor is used, and FIG. 5 is an explanatory diagram when a linear step motor is used.

First, a case where a voice coil motor is used will be described with reference to FIG. The optical scale 135 is slit at regular intervals. When the optical scale 135 attached to the actuator 10 moves, the amount of light received by the light receiving elements 137a and 137b from the light emitting element 136 changes. Since the position of the actuator 10 can be known from the change in the light amount, the position of the actuator 10 is controlled by moving the voice coil motor 140. Therefore, if the precision of the slit of the optical scale 135 is sufficient, the composite head 1 can be positioned at one data track pitch 20 according to the optical scale 135. Further, it is possible to control the voice coil motor 140 to position the composite head 1 with a resolution of one data track pitch of 20 or less according to a tracking error signal generated from a read signal of the servo pattern 12. In this case, the light scale 135 is used as the external scale.

Next, a case where a linear step motor is used will be described with reference to FIG. The linear step motor 141 steps the actuator 10 in the radial direction by a linear step motor control circuit (not shown). Also, micro-step feeding is possible.
Therefore, the composite head 1 is moved to the data track pitch 20 by step control or micro step control.
Further, it is possible to position the composite head 1 with a resolution of one data track pitch of 20 or less according to a tracking error signal generated from a read signal of the servo pattern 12.

Embodiment 2 FIG. In the servo format of the above embodiment, the servo pattern is recorded on each data track. However, the servo format can be simplified to avoid a decrease in storage capacity. FIG. 6 is an explanatory diagram of a servo format according to another embodiment. In the figure, 22 is a magnetic recording medium, 23 is the outermost data track, 24 is the data track of cylinder number i, 25 is the innermost data track, 26 is the 0th servo pattern of the outermost track, and 27 is 0 of the outermost data track. Servo pattern other than the 2nd
8 is the 0th servo pattern of the innermost data track, 2
Numeral 9 is a servo pattern other than the 0th innermost data track, 31 is a position where a servo pattern other than the 0th track of the data track having the cylinder number i should be, and 30 is a servo pattern of the data track having the cylinder number i.

Recording a servo pattern on each data track reduces the storage capacity.
The servo pattern is completely recorded only in the innermost data track 25, and the servo pattern is recorded only in the position of the 0th servo pattern in the other data tracks.
The amount of displacement in the radial direction due to expansion and contraction of the magnetic recording medium 22 can be known by using only one servo pattern 30 for each data track. The change in the shift amount for one rotation is determined by the servo patterns 26 and 27 on the outermost circumference and the servo pattern 2 on the innermost circumference.
You can find out at 8,29.

First, the servo pattern 2 other than the 0-th servo pattern 2 of the outermost data track starts from the outermost 0-th servo pattern 26.
Measure the deviation to 7. This measurement can be realized by generating a tracking error signal using only the 0th servo pattern 26 of the outermost data track, performing positioning, and measuring the amount of deviation of the servo pattern 27 other than the 0th servo pattern of the outermost data track. In a case where the digital control method is adopted, a more direct measurement method is to perform positioning control on the outermost data track 23 in the same manner as in the first embodiment. The output of the controller to the actuator at this time is stored for samples taken in by servo patterns 27 other than the outermost 0th servo pattern 27, and the difference between the sample of the 0th servo pattern 26 and the control output to the actuator is regarded as a deviation. is there. The same is measured for the innermost data track 74.
The following description is made for the data track of the cylinder number i.
The servo pattern 30 at the position 31 where the servo pattern other than the 0th track of the data track of the cylinder number i should be.
Can be predicted by interpolation from the deviation of the corresponding position of the servo pattern 27 on the outermost periphery and the deviation of the corresponding position of the servo pattern 29 on the innermost periphery. The number of cylinders between the outermost data track 23 and the innermost data track 74 is m, the number of cylinders between the data track 24 having the cylinder number i and the outermost data track 23 is e, and the number of cylinders other than 0 is the outermost data track. Xo, the deviation of the servo pattern 29 other than 0 in the innermost data track is xi, and the servo pattern 3 of the cylinder number i is xo.
Assuming that the position at 0 is x, the position x1 of the position 31 where the servo pattern other than the 0th track of the data track of the cylinder number i should be can be predicted by the following equation (1). x1 = x + {xi. (e + 1) + xo. (me)} / (m + 1) .. (1)

The follow-up control on the data track 24 of the cylinder number i is performed by generating a follow-up error signal using the servo pattern 30 on the magnetic recording medium 22 at a position where the servo pattern 30 exists, and at the position 31 where the other servo pattern should be. This is performed using an equation. When the digital control method is used, x in the above equation (1) may be output to the actuator of the controller (not shown) in the servo pattern 30 of the data track of the cylinder number i. x1
Is the output to the actuator of the controller at the position 31 where the servo pattern of the data track with the cylinder number i should be. Deviations change over time and need to be re-measured periodically. Basically, the magnetic recording medium 22 of each data track
Since there is only one upper servo pattern, the transient response characteristic is degraded. Although the positioning accuracy is deteriorated as compared with the first embodiment, the reliability is not so high because the core width of the write head 6 is wider than the core width of the read head 8, and even if a tracking error occurs, the influence on the amplitude of the read signal is small. Does not deteriorate.

Embodiment 3 FIG. It should be noted that the servo format can be further simplified from the servo format of the above embodiment in order to further prevent a decrease in storage capacity. FIG.
FIG. 8 is an explanatory diagram of a servo format according to another embodiment. In the figure, 22 is a magnetic recording medium, 23 is the outermost data track, 24 is the data track of cylinder number i, 25 is the innermost data track, 26 is the 0th servo pattern of the outermost track, and 27 is 0 of the outermost data track. The other servo pattern, 28 is the 0th servo pattern of the innermost data track, 29 is the servo pattern other than the 0th servo track of the innermost data track, and 32 is the position where the servo pattern of the data track of cylinder number i should be.

The servo pattern is the outermost data track 23
Is recorded only on the innermost data track 25. This greatly simplifies the servo format recording procedure. The actuator 10 has a function of positioning the composite head 1 according to an external scale (not shown) at one data track pitch 20 in order to record the servo format 11 and a function of following the calculated position of the data track 19 in order to follow. A function that allows the composite head 1 to be positioned according to a scale (not shown) with a resolution of one data track pitch of 20 or less (external precision positioning means 10)
b). The minimum resolution that can be positioned is the maximum deviation amount that does not decrease the reliability of the read signal of the data track 19.

The servo patterns 26 and 27 of the outermost data track and the servo patterns 28 and 29 of the innermost data track of the magnetic recording medium 22 are read out by positioning them at the center position of the data track 19 in the servo format. Measure and store the deviation. More specifically, the servo patterns 26 and 27 of the outermost data track and the servo patterns 28 and 29 of the innermost data track store the positions when positioning is performed so as to minimize the position error. Calculate the deviation from the center. The current position of each data track is calculated by equally distributing the difference between the deviation at the outermost circumference and the deviation at the innermost circumference to the servo pattern to all data tracks. The calculation formula is the same as that shown in the second embodiment. Here, x is the data track center position in the servo format. Since there is basically no servo pattern on the magnetic recording medium 22 for each data track, the transient response characteristics and the moving time between data tracks depend on the performance of the actuator. It is necessary to periodically re-measure the displacement of the actuator.
Although the positioning accuracy is deteriorated as compared with the first embodiment, the reliability is not so high because the core width of the write head 6 is wider than the core width of the read head 8, and even if a tracking error occurs, the influence on the amplitude of the read signal is small. Does not deteriorate.

Embodiment 4 FIG. In the second and third embodiments, two data tracks, the outermost data track and the innermost data track, are used as the data tracks for learning the change in the shift amount for one rotation. The data track to be learned can be three or more data tracks in order to more reliably predict the amount of shift for one rotation in. FIG. 8 is an explanatory diagram of a servo format according to another embodiment. In the figure, 22 is a magnetic recording medium, 23 is the outermost data track, 24 is the data track of the cylinder number i, 25 is the innermost data track, 35 is the middle data track, 26 is the 0th servo pattern of the outermost track, 27 Is a servo pattern other than the 0th servo pattern of the innermost data track, 28 is a 0th servo pattern of the innermost data track, 29 is a servo pattern other than the 0th servo track of the innermost data track, and 36 is a 0th servo pattern of the middle data track. , 37 are servo patterns other than the zeroth data track in the middle data track, and 32 is the position where the servo pattern of cylinder number i should be. In FIG. 8, the middle data track 35 is located exactly between the outermost data track 23 and the innermost data track 25, but anywhere between the outermost data track 23 and the innermost data track 25. You may.

The recording method of the servo format is the same as that of the third embodiment. However, the difference is that the complete servo format is also recorded on the middle data track. The measurement of the shift amount for one rotation is performed for the outermost data track 23, the innermost data track 25, and the middle data track 35. The calculation formula of the position x1 at the position 32 where the servo pattern should be in the data track of the cylinder number i is the same as in the second embodiment. Here, the number of cylinders between the two data tracks on which the complete servo format is recorded on both sides of the data track 24 having the cylinder number i is m,
The number of cylinders between the data track 24 having the cylinder number i and the outer data track of the two data tracks is e, the deviation of the servo pattern other than the 0th of the outer data track is xo, The deviation of servo patterns other than the 0th data pattern on the inner data track is xi, and the center position of the data track of cylinder number i in servo formatting is x. It is clear that the accuracy of the prediction by the above formula is improved when the number of data tracks between the data tracks for which the displacement amount for one rotation is measured is reduced.

Embodiment 5 FIG. Note that a lower head may be used for reading the servo data instead of the upper head.
FIG. 9 is an explanatory diagram of a servo format according to another embodiment.
In the figure, reference numerals 124 to 131 denote servo burst patterns.

Next, the operation will be described with reference to FIG. First, a servo format writing method will be described. First, after DC erasure, the servo burst patterns 128, 12 are read at a data track pitch 20 using the lower head 2 or the lower preceding erase head 4.
Write 9, 130, 131. Next, the servo burst patterns 124, 125, 126, and 127 are positioned while using the tracking error signals generated from the servo burst patterns 128 and 129 or the tracking error signals generated from the servo burst patterns 130 and 131, and the lower head is positioned. Writing is performed using the second or lower leading erase head 4. Servo burst patterns 124, 125, 126, 1
27 may be written using the write head 6. Lower head 2, write head 6, and read head 8
Are shifted by x in the radial direction. The data track 19 and the servo pattern 12 are written with the relative position shifted by the shift amount x.

Next, a method of generating a tracking error signal will be described. When a tracking error signal is generated using the difference between the read amplitudes of the servo burst patterns 130 and 131, the data track 1 that can be positioned using the tracking error signal is used.
9a is every other data track. Therefore, the data track 19b in FIG. 9 cannot be positioned as it is. Therefore, the servo burst patterns 130 and 131 are one in order to enable positioning even in the data track 19b.
The servo burst patterns 128 and 129 shifted by the data track pitch are written. Since the core width of the lower head 2 for reading the servo pattern is wider than the core width of the read head 8, the amplitude value of the read signal increases accordingly, and the reliability of the tracking error signal improves.

Embodiment 6 FIG. Embodiment 5 can be further simplified as follows. FIG. 10 is an explanatory diagram of a servo format according to another embodiment (sixth embodiment). In the figure, 142 and 1
43 is a servo burst pattern.

The writing method of the servo format in the sixth embodiment is the same as that in the fifth embodiment. That is, after DC erasing, one data track pitch 2
0, using the lower head 2 or the lower preceding erase head 4, as shown in FIG.
Write 42, 143. The tracking error signal is generated using the read amplitude of the servo burst patterns 142 and 143. Each of the servo burst patterns 142 and 143 has a radial period of the amplitude of 2 of one data track pitch 20.
Since the phase difference in the radial direction is one data track pitch 20, the two read amplitudes are used to calculate
Generate a tracking error signal. In the case of this servo format, positioning of all data tracks can be performed by the servo burst patterns 142 and 143. Therefore, a servo area is small and the servo burst pattern 14 when the composite head is following the data track.
Since the read signal amplitudes 2 and 143 are larger than the read signal amplitudes of the servo burst patterns 130 and 131 of the fifth embodiment, the reliability of the tracking error signal is further improved.

Embodiment 7 FIG. In any one of the first to fifth embodiments, the provision of the means for determining whether the read result of the servo data matches the write data and determining the performance of the magnetic recording medium contributes to the improvement of the reliability of the apparatus. . FIG. 11 is a configuration diagram of a flexible magnetic disk drive of another embodiment (Embodiment 7) including means for reading the written servo data to determine the performance of the magnetic recording medium. In the figure, 1 is a composite head physically connected to an actuator 10, 10 is an actuator, 2
2 is a magnetic recording medium, 81 is a disk controller, 80
Is a recording / reproducing circuit connected to the composite head 1; 302 is a reading means including the composite head 1 and the recording / reproducing circuit 80;
38 is a spindle motor for rotating the magnetic recording medium 22; 113 is an external scale physically connected to the actuator 10; 114 is an external scale detecting circuit for detecting the position of the actuator 10 using the external scale 113; A data detection circuit connected to the reproduction circuit 80, 116 is an amplitude detection circuit connected to the recording / reproduction circuit 80, 117a and 117b are data detection circuits 11
5, a sample and hold circuit connected to the amplitude detection circuit 116, a control circuit 118 connected to the actuator 10, a mismatch detection means 119 connected to the sample and hold circuit 117a, and an amplitude 120 connected to the sample and hold circuit 117. The failure detection means 121 is a counter connected to the mismatch detection means 119 and the amplitude failure detection means 120, and 122 is a determination circuit (output means 30) for recognizing the performance of the magnetic recording medium 22 from the value of the counter 121.
1) and 123 are flexible magnetic disk devices configured as described above.

Next, the operation will be described. The composite head 1 operates as a converter for writing and reading the magnetization reversal of the magnetic recording medium 22. The composite head 1 is moved by the actuator 10 and writes and reads data on and from the magnetic recording medium 22 via the recording / reproducing circuit 80 at an arbitrary position on the magnetic recording medium 22.

Data writing is performed by the disk controller 81. Data reading is converted into digital data by the data detection circuit 115 and is performed by the disk controller 81. The amplitude detection circuit 116 detects the amplitude of the read waveform. In order to read the servo data, both digital data and amplitude are required. Each output of the data detection circuit 115 and the amplitude detection circuit 116 is sampled and held by sample and hold circuits 117a and 117b by a servo data position detection circuit (not shown).
The servo data can be read by sampling and holding the data. The control circuit 118 outputs an appropriate signal to the actuator 10 using the servo data and the position detected by the external scale detection circuit 114,
The composite head 1 can be positioned on a certain track.

The sample and hold circuits 117a, 117
The output of 7b corresponds to the position of the composite head 1 and is compared with the data written at that position. The mismatch detecting means 119 and the amplitude defect detecting means 120 compare the data in which the outputs of the sample and hold circuits 117a and 117b are written, or a required amplitude specified value at that position, and indicate a defective case. Output a signal. The counter 121 counts the output. The determination circuit 122 determines the value of the counter 121 from the value of the magnetic recording medium 22.
Judgment of performance and output to outside.

The disk controller 81 has a function of writing a servo format in response to an external signal, and determining the performance of the magnetic recording medium 22 by the above means, and outputting the result to the outside.

By providing such means, it is expected that the writing reliability of the servo format is improved.

Embodiment 8 FIG. Hereinafter, another embodiment (Eighth Embodiment) of the present invention will be described with reference to FIG. This embodiment is intended to accurately detect the position on the medium without depending on the rotation fluctuation of the spindle motor 38. In the figure, 75 is an optical detector output signal, 76 is an index detector output signal, 77 is a logic circuit, 81 is a disk controller, 8
0 is a recording / reproducing circuit, 108 is an index signal generated by the logic circuit 77, and 109 is a sector reference signal generated by the logic circuit 77. Reference numeral 303 denotes a divided signal generation unit including the logic circuit 77 and the optical detector output signal 75. FIG. 13 is a diagram showing the relationship between the output signal of the optical detector and the rotation angle of the rotor. In the figure, reference numeral 106 denotes an output of the optical detector 59a, and 107 denotes an output of the optical detector 59b. FIG.
Are the track format and the logic circuit output employed in this embodiment. FIG. 15 is a diagram showing an output at the time of adjustment of the index detector.

The spindle motor 38 has the same configuration as the conventional example. The output signal 75 of the optical detector for detecting the rotation angle of the rotator and the output signal 76 of the index detector are input to the logic circuit 77. The output signal of the logic circuit 77 is input to the disk controller 81. Although not shown in the figure, the disk controller 81 includes a format control unit for performing formatting. A control signal 78 and a data signal 79 are bidirectionally connected from the disk controller 81 to the recording / reproducing circuit 80.

Next, the operation will be described with reference to FIGS. The optical detector 59b outputs a signal 107 as shown in FIG. 13 (hereinafter, rotation angle signal) based on the rotation angle θ of the rotor.
Is output. Usually 3 per minute for flexible disk drives
The magnetic recording medium 22 is rotated at 00 rotations, and the rotation angle signal interval is about 3.9 milliseconds. The logic circuit 77 uses the output of the index detector and the rotation angle signal 107 as shown in FIG.
The sector reference signal 109 shown in FIG. The index position 96 is set to a position where the rotation angle signal 107 which appears after the index detector detects the index is generated.

Using this sector reference signal 109, the format controller writes the format data of FIG. 14 for each sector. When writing format data, it is not necessary to consider rotation fluctuations, and sectors can be accurately written on a magnetic recording medium. Therefore, the track gap 50 (see FIG. 24) can be omitted.

When the format as described in the first to fifth embodiments, that is, the format includes a servo pattern, the servo pattern can be accurately written on the magnetic recording medium at the same central angle.

Although the sector position on the magnetic recording medium and the position change of the sector reference signal 109 do not occur in the same device, the relative position of the rotation angle signal generation position by the rotation speed detection pattern 58 and the optical detector 59b between different devices. It can occur due to positional relationship. However, for this, the index detector 41 has the output 10b of the optical detector 59b of FIG.
By performing processing adjustment so that the index detection signal 76 enters between the edges E1 and E2 of No. 7, it is possible to obtain the index signal 108 at an accurate index position.

Embodiment 9 FIG. In the eighth embodiment, the black and white pattern in which the rotation angle of the rotator 39 is fixed to the rotator is used as the excitation phase switching signal by the optical detector to generate the divided signal. FG formed on a printed circuit board for fixing the magnetizing of the rotor and the driving coil
A similar effect is obtained by a configuration in which the output of the FG composed of a coil is also used as a constant speed control system.

FIG. 16 shows the configuration of the rotation angle detector used in this embodiment. Reference numeral 304 denotes a rotational angular velocity detecting unit including the frequency generator 98, the waveform shaping circuit 99, and the differentiating circuit 100. The constant speed control system using the FG is the same as the conventional example.
In the eighth embodiment, the output of the differentiating circuit 100 is input to the logic circuit 77 instead of the output of the optical detector.

The output phase of the FG 98 is synchronized with the position of the magnetic pole of the rotor 39. The output of the differentiating circuit 100 is FG
A pulse is generated by detecting a point at which the output 98 has the same phase. This pulse position indicates the zero cross point of the FG output. By using this pulse as the sector reference signal 109, a pulse synchronized with the rotation of the rotor is obtained.

The obtained sector reference signal 109 can be used not only for the sector arrangement at the time of formatting, but also for reading a signal written on a magnetic recording medium.

By counting the sector reference signal from the index signal, it is possible to know which sector the magnetic head is currently on. Therefore, it is possible to simplify or eliminate the identification unit for sector identification.

In addition to using the sector reference signal as the sector identification information, it can be used as a detection signal of servo information when the sector servo method is adopted.

In the sector servo, servo information is recorded in a part of a sector, and a servo information identifier for detecting a recording position similar to the sector identifier is simultaneously recorded.
By writing this servo identifier at the position where the sector reference signal 109 is generated, it becomes possible to take in servo information at an accurate position based on the sector reference signal 109.

Embodiment 10 FIG. In the eighth embodiment, the relative positional relationship between the rotation angle signal generation positions by the angle detection pattern and the optical detector is adjusted by processing, but there is also a method of electrically adjusting by using a delay element.

In the eighth embodiment, the output of the rotation angle signal is 3.
It occurs at a cycle of 9 milliseconds. Since the frequency of the FG signal of the second embodiment is also several hundred hertz, the period is several milliseconds. Even if the rotation angle signal is electrically delayed for adjustment with the fixed position of the magnetic recording medium by the chucking mechanism, the maximum is 3.9 milliseconds. Although the synchronization between the rotation angle on the magnetic recording medium and the delayed rotation angle signal is not accurate due to the electrical delay, the amount of position error with respect to the magnetic recording medium due to the rotation fluctuation within the delay time indicates the delayed rotation angle signal. Can have sufficient accuracy as a reference signal.

In the eighth embodiment, the rotation angle detector of the rotor 39 is constituted by a black-and-white pattern fixed to the rotor and the optical detector, but the flat cylindrical portion of the rotor 39 (hereinafter referred to as flywheel). ) To print a black and white pattern,
Obviously, the same effect can be obtained even when the configuration is combined with a reflection type optical detector.

Further, a rotation angle detecting unit configured using a magnetic pole of a magnetized portion for driving the rotor or a magnetic pole magnetized on a portion different from the magnetized portion for driving the rotor and a Hall element as a magnetic detecting element. A similar effect can be obtained by using a vessel.

The same effect can be obtained by using a rotation angle detector constituted by a slit provided on the flywheel and a transmission type optical detector.

The same effect can be obtained by magnetizing the peripheral portion of the flywheel or fixing a magnetized tape and using a rotation angle detector configured by combining with a magnetic detecting element.

Embodiment 11 FIG. Hereinafter, another embodiment of the present invention will be described. The eleventh embodiment is for eliminating a redundant portion when writing data. FIG. 17 is a schematic view of the flexible magnetic disk drive of this embodiment. In the figure, reference numeral 86 denotes a reflecting member that reflects a laser beam or the like,
Reference numeral 87 denotes a length measuring device that measures the distance to the object using a laser beam or the like, and outputs a voltage of A · rx + B when the measured distance is rx. Reference numeral 304 denotes a reflecting member 86, a length measuring device 87, and a differentiating circuit 88. A rotational angular velocity detecting means, 88 is a differentiating circuit for outputting a voltage of C · (dVin1 / dt) + D when the input voltage is Vin1, and 89 is a differential circuit of F = G · (Vin2-D) when the input voltage is Vin2. This is an oscillator that performs oscillation (writing frequency adjusting means). A, B, C,
D and G are constants,

[0087]

(Equation 1)

The configuration is such that These can be easily configured with electronic circuits. The reflection member 86 has the same rotation center as the spindle motor, and is mounted so as to rotate in synchronization with the spindle motor. Assuming that the rotation angle is a [rad], the distance r from the rotation center of the reflection member 86 to the end of the reflection member 86 is r = r0 as shown in FIG.
+ (R1−r0) · a / 2π. Assuming that the distance from the rotation center of the reflecting member 86 to the length measuring device 87 is r2, the distance rx from the end of the reflecting member to the length measuring device is rx = rx (θ) = r2-r = r2-r0-.
(R1−r0) · a / 2π.

Next, the operation will be described. Since a = a (t) when the spindle motor is rotating, r
x is a functional of t. Now, the length measuring device 87 includes the reflecting member 8.
The distance rx to the end of 6 is measured continuously, and its time derivative is

[0090]

(Equation 2)

Is obtained. Therefore, the rotation angle w of the spindle motor is

[0092]

(Equation 3)

From the time derivative of rx, the rotational angular velocities w are continuously collected (except for a = 0). Therefore,
From this w (t), the oscillation frequency F is calculated as F = F0 · w / w0
When the oscillator is oscillated, the recording area 84 on the magnetic recording medium for writing data of K [bit] is obtained.
The length L (see FIG. 31) is

[0094]

(Equation 4)

The length becomes the same as that when writing at the time of rotation at the prescribed rotational angular velocity w0.

The length measuring device, the differentiation circuit,
When the length measuring device detects the distance rx, the oscillation frequency F of the oscillation circuit becomes

[0097]

(Equation 5)

As described above, the length L of the recording area is constant irrespective of w.

Embodiment 12 FIG. Next, another embodiment will be described.
FIG. 19 is a schematic view of a flexible magnetic disk drive according to another embodiment (embodiment 12). In the figure, reference numeral 90 denotes a disk having the same center of rotation as the spindle motor and having holes at every equal center angle b [rad].
Reference numeral 1 denotes a light emitter for irradiating light to the disk, 92 denotes a light receiver for receiving reflected light from the disk and generating a pulse when the amount of received light changes. Reference numeral 94 denotes a multiplier (writing frequency adjusting means) for multiplying the pulse frequency by n. 304 is a rotational angular velocity detecting means.

Next, the operation will be described. Since the disk 90 rotates synchronously with the spindle motor, the light receiver generates a pulse when the spindle rotates by the angle b [rad]. First, the spindle motor is driven at a specified rotational angular velocity w.
Consider the case where the rotation is at 0. At that time, the pulse interval y0 is y0 = b / w0. At that time, the data transfer speed between the controller and the recording / reproducing circuit (which is equal to the oscillation frequency of the clock oscillation circuit) is F0, and the oscillation cycle T0 of the clock oscillation circuit is T0 = 1 / F0.
Therefore, there is a certain constant n, and y0 = n · T0, which means that the frequency of the pulse of the encoder multiplied by n is the oscillation period of the clock oscillation circuit. That is, n = y0 / T0 = F0.b / w0.

When the pulse interval is y, the rotational angular velocity w of the spindle motor 38 is w = b / y. The cycle of the signal obtained by multiplying the pulse interval by n is

[0102]

(Equation 6)

And the frequency is

[0104]

(Equation 7)

Is as follows. This is equal to the data transfer speed F between the controller recording and reproducing circuits described above. Therefore,
The frequency of the pulse from the encoder is n = F0 · b / w0
The same effect as that of the eleventh embodiment can be obtained by using the multiplied signal instead of the signal of the oscillation circuit 89. In this case, w to be measured is exactly the average angular velocity between the pulses, and the above is not exactly correct, but if b is sufficiently small, it is practically sufficient.

Embodiment 13 FIG. Another embodiment will be described. FIG. 20 is a schematic view of a flexible magnetic disk drive of another embodiment (Embodiment 13). In the figure, reference numeral 85 denotes a magnetic recording medium on which servo write has been performed in advance and servo information is written on data tracks at regular intervals, and reference numeral 95 denotes a servo signal detecting circuit (rotational angular velocity detecting means 304) for detecting a servo signal and outputting a pulse. ).

Next, the operation will be described. In the twelfth embodiment, the rotational angular velocity of the spindle motor was measured by the encoder 93. In this case, the disk 90 must be formed with high accuracy, and there is a problem in cost. Therefore, when writing data to the magnetic recording medium 85 in which servo signals have been written in advance at regular intervals, a pulse generated by the servo signal detection circuit 95 may be used instead of a pulse generated by the encoder 93. Since the servo signal is generally written at the same center angle on the data track by a high-accuracy servo data track writer or the servo write function described in the eighth embodiment,
Embodiment 1 by extracting a servo signal and generating a pulse
The same effect as that of No. 2 is obtained, and the encoder 93 becomes unnecessary.

Embodiment 14 FIG. Further, in the first embodiment described above,
To 6, and any of Examples 7 to 9,
If any one of the embodiments 10 to 12 is combined, the reliability of the tracking error signal can be improved, and the position on the magnetic recording medium can be accurately detected irrespective of the rotation fluctuation of the spindle motor 38. Obviously, it is possible to obtain a flexible magnetic disk device that can eliminate a redundant area when performing data writing, has an accurate self-servo writing function, and can eliminate a redundant area when writing data.

As described above, the flexible magnetic disk drive has an upper head composed of a preceding write head and a rear read head having a smaller core width than the preceding write head, and a core width larger than the write head having the preceding erase head. Means for recording a servo format having a narrower data track pitch by using the lower head, comprising: a composite head in which a wide lower head is arranged in parallel via a magnetic insulating layer; and a head having a data track pitch of the servo format. Means for positioning the
The composite head includes means for positioning the composite head at a resolution equal to or less than the data track pitch using a servo signal on a magnetic recording medium, and a preceding write head having a wider core width than a head used for reading.

Further, another flexible magnetic disk drive includes, in addition to the above means, means for positioning the composite head at a resolution not higher than the data track pitch using means other than servo signals recorded on a magnetic recording medium. Is also provided.

Further, another flexible magnetic disk drive detects a rotation of a rotor of a spindle motor by a predetermined angle, generates a signal for dividing one rotation of the spindle motor into a plurality of rotations, and magnetically records the generated divided signal. This is a reference position signal on the medium.

Further, another flexible magnetic disk drive generates a signal for dividing the rotation by using a signal for switching the excitation phase of the driving coil.

Further, another flexible magnetic disk drive generates a signal for dividing the rotation from the phase of the output of a speed detector disposed in a spindle motor for controlling the rotation speed of a rotor.

Further, another flexible magnetic disk drive has means for measuring the rotational angular velocity w of the spindle motor, and means for adjusting the data transfer speed between the controller recording / reproducing circuits corresponding to w. is there.

Therefore, according to the above-described embodiment, the flexible magnetic disk device follows a servo format having a narrower data track pitch by using a head having a leading erase head for realizing backward compatibility. A highly reliable servo pattern wider than the data track can be recorded. Further, since the head for recording data has a wider core width than the read head, highly reliable recording can be performed even if the tracking error is large.

Further, since another flexible magnetic disk device has a function of positioning with a resolution equal to or smaller than the data track pitch, a large-capacity device can be configured by using a simple and small-capacity servo format.

Further, a magnetic recording medium position detection signal synchronized with the rotation angle of the magnetic recording medium can be easily created.

Further, a plurality of points whose positions on the magnetic recording medium can be detected can be provided.

Further, since the excitation phase switching signal of the driving coil is used, the position of the rotor can be detected without adding a new detector.

Also, since the phase of the output of the speed detector for controlling the rotation speed is used, the position of the rotor can be detected without adding a new detector.

Further, the data transfer speed F between the disk controller and the recording / reproducing circuit is set to F = F0.w / w0 based on the measured rotational angular speed w.
The recording area is equal to the case where there is no rotation fluctuation, and the necessary redundant area can be eliminated according to the rotation fluctuation.

[0122]

As described above, according to the present invention, a plurality of reference points on a magnetic recording medium can be provided by a simple configuration without adding a large number of parts to a conventional magnetic recording / reproducing apparatus. At the same time, there is no need to set a redundant rotation fluctuation absorption region, and the effect that the usage efficiency on the magnetic recording medium can be improved can be obtained. Further, there is an effect that the identification signal indicating the purpose can be simplified or omitted when data is read. In addition, the function of creating and discriminating the identification signal can be simplified or omitted. In addition, there is an effect that it is possible to easily perform adjustment such that the positional relationship between the magnetic recording medium and the rotor is common among a plurality of apparatuses. Further, there is an effect that the servo pattern can be accurately written.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a servo format according to an embodiment of the present invention.

FIG. 2 is a perspective view of a composite head according to an embodiment of the present invention.

FIG. 3 is a configuration diagram of one embodiment of the present invention.

FIG. 4 is an explanatory diagram of a positioning function according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a positioning function according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram of a servo format according to another embodiment of the present invention.

FIG. 7 is an explanatory diagram of a servo format according to another embodiment of the present invention.

FIG. 8 is an explanatory diagram of a servo format according to another embodiment of the present invention.

FIG. 9 is an explanatory diagram of a servo format according to another embodiment of the present invention.

FIG. 10 is an explanatory diagram of a servo format according to another embodiment of the present invention.

FIG. 11 is a configuration diagram of a flexible magnetic disk drive according to another embodiment of the present invention.

FIG. 12 is a schematic view of a flexible magnetic disk drive according to another embodiment of the present invention.

FIG. 13 is a diagram showing a relationship between an output signal of an optical detector and a rotation angle of a rotor according to another embodiment of the present invention.

FIG. 14 is an explanatory diagram of a data track format in another embodiment of the present invention.

FIG. 15 is a diagram showing an output at the time of adjustment of an index detector according to another embodiment of the present invention.

FIG. 16 is a schematic view of a flexible magnetic disk drive according to another embodiment of the present invention.

FIG. 17 is a schematic view of a flexible magnetic disk drive according to another embodiment of the present invention.

FIG. 18 is a view for explaining the operation of the flexible magnetic disk drive according to another embodiment of the present invention, and shows the relationship between the rotation angle of the spindle motor and the distance from the rotation center of the reflector to the end of the reflector. It is a thing.

FIG. 19 is a schematic view of a flexible magnetic disk drive according to another embodiment of the present invention.

FIG. 20 is a schematic view of a flexible magnetic disk drive according to another embodiment of the present invention.

FIG. 21 is an explanatory diagram of a servo format of a conventional flexible magnetic disk drive.

FIG. 22 is a schematic diagram of a configuration of a conventional flexible magnetic disk drive.

FIG. 23 is an explanatory diagram of a generation position of an index signal in a conventional flexible magnetic disk device.

FIG. 24 is a diagram showing a data track format of a conventional flexible magnetic disk drive.

FIG. 25 is a development view of a spindle motor of a conventional flexible magnetic disk drive.

FIG. 26 is a development view of a spindle motor of a conventional flexible magnetic disk drive.

FIG. 27 is a development view of a spindle motor of a conventional flexible magnetic disk drive.

FIG. 28 is an explanatory diagram of speed control of a spindle motor of a conventional flexible magnetic disk drive.

FIG. 29 is a system schematic diagram of a conventional flexible magnetic disk drive.

FIG. 30 is a diagram for explaining rotation fluctuation of a spindle motor.

FIG. 31 is a diagram illustrating how a recording area on a magnetic recording medium expands and contracts due to rotation fluctuation of a spindle motor.

[Explanation of symbols]

1 composite head (reading means), 2 lower heads, 3
Core width of lower head, 4 lower leading erase head,
5 core width of lower leading erase head, 6 write head, 7 core width of write head, 8 read head, 9 core width of read head, 10 actuator, 10a coarse positioning means, 10b precision positioning means (external precision positioning means), Reference Signs List 11 servo format, 12 servo pattern, 13-18 servo burst pattern, 201 data track pitch, 22 magnetic recording medium, 38 spindle motor, 39 rotor, 40
Chucking mechanism (medium fixing means), 41 index detector (start point detecting means), 75 optical detector output signal (split signal generating means), 76 index detector output signal, 77 logic circuit (split signal generating means), 86 A reflecting member for reflecting a laser beam or the like (rotational angular velocity detecting means);
87 length measuring device (rotational angular velocity detecting means), 88 differentiating circuit (rotating angular velocity detecting means), 89 oscillation circuit (writing frequency adjusting means), 90 disk (rotating angular velocity detecting means),
91 light emitting device (rotational angular velocity detecting means), 92 light receiving device (rotating angular velocity detecting means), 93 encoder (rotational angular velocity detecting means), 94 multiplication circuit (writing frequency adjusting means), 95 servo signal detecting circuit (rotating angular velocity detecting means) ), 98 frequency generator (rotational angular velocity detection means),
99 Waveform shaping circuit (rotational angular velocity detecting means), 100
Differentiating circuit (rotational angular velocity detecting means), 101 sawtooth wave generating circuit, 303 divided signal generating means, 304 rotational angular velocity detecting means.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuzo Maruta 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Keiichi Nishikawa 2-3-2 Marunouchi, Chiyoda-ku, Tokyo 3 F term in Ryo Denki Co., Ltd. (reference) 5D044 AB01 BC01 CC04 DE02 DE37 EF05

Claims (9)

[Claims] 1. A medium fixing means for mounting a magnetic recording medium at the same angle with respect to a rotor of a spindle motor for rotating a disk-shaped magnetic recording medium, and a start point detecting means for determining a start point and an end point of a data track. A magnetic recording / reproducing apparatus for recording / reproducing data of a fixed length, wherein the magnetic recording / reproducing apparatus is configured such that the rotation start point determined by the start point detecting means is set at 1
A divided signal generating means for generating a divided signal for dividing the rotation into a plurality by detecting a rotation angle of a rotor of a spindle motor, wherein a reference position on a data track is determined using the divided signal. Recording and playback device. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the divided signal generating means also serves as a rotor rotation angle detecting means for controlling a spindle motor. 3. A method according to claim 1, further comprising: a rotational angular velocity detecting means for detecting a rotor rotational speed of the spindle motor; and a split signal generating means for generating a divided signal by using an output of the rotational angular velocity detecting means. The magnetic recording and reproducing apparatus according to claim 1. 4. The magnetic recording / reproducing apparatus according to claim 2, wherein an excitation phase switching signal of a driving coil of the spindle motor is used as the divided signal generating means. 5. A magnetic sensor in which a magnetic field that is different from or the same as that of the driving magnetic field generating unit of the rotor is disposed on a substrate to which the driving coil is fixed is used as the divided signal generating means. 3. The magnetic recording / reproducing apparatus according to claim 2, wherein the magnetic recording / reproducing apparatus performs detection. 6. A servo signal is recorded in a part of a sector, and a positioning control of a magnetic head is performed on a data track by using the servo signal. A servo signal synchronized with rotation of a spindle motor using a divided signal. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein sampling is performed. 7. A rotational angular velocity detecting means for detecting a rotational angular velocity of a spindle motor, and a write frequency adjusting means for adjusting a data write frequency so as to write a constant amount of data at a constant angle using the rotational angular velocity. The magnetic recording / reproducing apparatus according to claim 1, further comprising: 8. When the distance r from the rotation center of the spindle motor is a rotation angle a [rad], r = r0 + (r
1−r0) × (a / 2π) (where r0 and r1 are constants)
A reflecting member configured to be: a length measuring device outside the reflecting member and measuring a distance to the reflecting member; a differentiating circuit for differentiating an output of the length measuring device; 8. The magnetic recording / reproducing apparatus according to claim 7, further comprising an oscillation circuit for adjusting an oscillation frequency based on a value of an output voltage of the circuit. 9. The encoder according to claim 7, further comprising: an encoder for generating a pulse at each equal angle of the spindle motor; and a multiplier circuit for multiplying the frequency of the pulse generated by the encoder by n. Magnetic recording and reproducing device.