JPH1166690A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of servo performance caused by the influence of vibration or impacts by specifying a recording/reproducing track position based on recording/reproducing track information read and reproduced by one of a pair of magnetic heads and recording/reproducing data by the other head. SOLUTION: A sector is detected by a sector detector 64 based on sector information, and based on its detected information, the timing signal of a servo clock or the like is generated from an information input timing by a timing generator 65. Then, based on this, timing synchronization is performed for servo information by a servo controller 46, and the processing throughput improvement of a servo unit is secured. After positioning is performed like this, data recording/reproducing with a disk is performed via a head located in a side opposite the surface of the disk having a magnetic head used therefor. Positioning control is performed also during recording/reproducing, unnecessary vibration components are suppressed and a servo system having resistance to external disturbances is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive, and more particularly to a mobile computer such as a portable computer or a storage peripheral device installed in a mobile terminal such as a thin high-density magnetic disk drive. The present invention relates to a recording / reproducing apparatus which is an optimum magnetic disk apparatus and which is required to have high density at the same time as being ultra-thin and satisfy high reliability and high precision positioning.

[0002]

2. Description of the Related Art FIGS. 5 (a) and 5 (b) show the configuration of a conventional small magnetic disk drive, and FIG. 6 shows positioning information and a sector used in a conventional sector servo system. The schematic configuration of the internal positioning information and the format of the user information are respectively shown.

FIG. 5A is a perspective view of a general small magnetic disk drive, showing a state where a top cover is opened, and FIG. 5B is a top cover of the small magnetic disk drive. It is a perspective view showing the structure in the state where 34 was closed. In the figure, 1 is a magnetic disk drive housing, 2 is a magnetic disk, 3 is a spindle motor, 4 is a recording / reproducing separation type head (hereinafter, referred to as a magnetic head unless otherwise specified), and 6 is an actuator arm. , 7 are an actuator carriage, 8 is a head preamplifier, and 9 is a flexible cable. The magnetic disk device rotates the magnetic disk 2 by rotating a spindle motor 3 for rotationally driving the magnetic disk 2 which is a magnetic recording medium.
The information is recorded / reproduced on the magnetic disk 2 by a recording / reproducing separation type head (hereinafter, referred to as a magnetic head unless otherwise specified) 4 held at the end of the disk. The magnetic disk 2 has a large number of recording tracks formed concentrically, and each recording track is divided into a plurality of sectors, and data is magnetically recorded in sector units.

One end of the actuator arm 6 is rotatably supported by a drive mechanism (not shown), and the other end is rotatable in a direction along the surface of the magnetic disk 2 by being rotated by the drive mechanism. It has become. The other end of the actuator arm 6 supports one end of the actuator carriage 7, whereby the magnetic head 4 moves the track position on the surface of the magnetic disk 2 with the rotation of the actuator arm 6. Can be.

[0005] Information recorded / reproduced to / from the tracks of the magnetic disk 2 is amplified as electrical signals by an external controller (not shown) through a flexible cable 9 by a head preamplifier 8 provided inside the magnetic disk drive housing 1. It is processed and is converted into magnetic information by the magnetic head 4 via the actuator carriage 7, the actuator arm 6, the flexible cable inside the housing (not shown) provided on the head suspension, and the head lead wire. Exchanged between Information exchanged between the magnetic disk 2 and the magnetic head 4 is performed at a predetermined position on the magnetic disk. At this time, the positioning of the magnetic head 4 is controlled by a voice coil motor (not shown) which is an actuator. .

In this positioning control, the positioning information is reproduced by the magnetic head 4 based on the positioning information written on the magnetic disk 2 in advance, and the external positioning is performed so as to be positioned at a predetermined track position. Feedback control is performed by the controller.

FIG. 6A is a diagram showing a schematic configuration of a format per sector of a recent small magnetic disk drive. In a magnetic recording disk device, such a predetermined format is applied to a magnetic disk at a manufacturing stage.

[0008] The format usually includes "track information".
And “positioning information”. Of these,
The “track information” is information indicating which track on the magnetic disk 2 the magnetic head is located when performing the positioning control, and the “positioning information” is information for causing the magnetic head to accurately follow the track. is there. These two types are collectively referred to as “servo information”. These "servo information" are information indispensable for the positioning control of the magnetic head, and the conventional format adopts a configuration as shown in FIG. Referring to FIG. 6A, the "servo information" portion includes an "AGC area section" 50 storing AGC information necessary for AGC (auto gain control) control for suppressing reproduction output fluctuation.
Then, there is an "erase code area section or sector code area section" 52 for detecting a sector,
Next, there are an "address code area" 51 in which track information is recorded, a "burst code area" 53 used for positioning control, and a "gap" 54 used to separate user data. It is composed of "Servo information" consisting of these 50 to 54
Following the area, a “user data identification unit” 55 comes. Thereafter, a “storage area” 56 is provided. This “storage area” 56 is open to the user, and user data is stored in this area.

The "user data identification section" 55 includes a clock synchronization signal (PLL signal), an adaptive equalization training signal, and a cue signal, and is necessary for identifying user data such as a logical sector number. Data is recorded.

Generally, as described above, servo information is
When a magnetic disk drive is manufactured using a dedicated device for writing servo information called a servo writer, predetermined tracks and sectors are recorded in advance. As for the user identification signal, there are a signal recorded at the same time as the user data is actually recorded and a signal recorded at the time of factory shipment.

A gate signal for reproducing or recording each data is added below each format data.

Normally, a magnetic disk device waits in a servo mode unless any operation signal is issued from a host computer. There are various states in the standby state of the servo mode. [I] “a state in which positioning control is performed at an arbitrary track position” [ii] “a non-positioning state”, [i]
ii] “Only the spindle motor is rotating” [iv]
There are "the spindle motor speed itself is lower than usual" and others, such as standby mode (above [i]), sleep mode (above [ii]), save mode (above [iv]), etc. It is named and prepares for operating signals from the host computer in the appropriate mode.

Of these mode states, the one with the fastest response is the mode state in which positioning control is performed at an appropriate track position. Then, when the servo mode is shifted to this operation mode, when a recording and reproducing action occurs from the host computer,
It immediately moves to a predetermined track position, and positioning control is performed at that track position. Therefore, in this servo mode, the same operation as in the servo mode at the time of the normal recording / reproducing action is performed. In this mode or the user data recording / reproducing operation mode, the drive unit for controlling the spindle motor and the actuator drive mechanism and the servo circuit for performing the servo control of the spindle motor are shown in FIGS.
The respective gate signals as shown in (i) and (m) are generated and these are servo-controlled.

Conventionally, a servo circuit first detects a sector detection signal such as an erase signal from "servo information" recorded on a magnetic disk. Thereafter, the servo clock is driven to run on the basis of the synchronization signal written in the header of the address code. While counting this clock, gate signal control is performed so as to open a predetermined gate signal at a predetermined servo information position.

Therefore, as for the gate signal of the AGC section, the gate opening / closing timing is generated by the clock which is self-run by the synchronization signal one sector before. The “track information” is recognized by detecting the “cylinder code”, and the positioning control is performed using a signal obtained by reproducing and processing the “burst code”.

Next, the case where the recording / reproducing operation of the user data is performed will be briefly described. Assuming that the recording / reproducing operation signal is issued from the host computer in the servo mode, the "PLL" of the "user data identification signal" at the rear of the gap signal following the "burst code"
The PLL circuit generates a PLL gate signal based on each gate signal generated by the servo circuit system based on the sector signal, and opens and closes the gate in the area where the PLL signal exists. The "PLL synchronization signal" is mainly recorded at the same time when user data is recorded.

This signal accurately synchronizes with the frequency of the user data recording signal and synchronizes the reproduction clock. After the PLL synchronization, the reproduction circuit detects the training signal for adaptive equalization, and after adjusting the equalization constant,
After detecting the header of the user data and detecting and decoding predetermined information recorded in the header portion, arbitrary user data is recorded or reproduced by opening and closing a recording / reproducing gate signal in a data storage area.

In order to access the user data in this manner, the gate signal generation timing required for the first PLL synchronization is received from the servo circuit. After the PLL synchronization is performed, the operation of the circuit system mainly includes the channel operation. It is controlled by a signal processing circuit system.

Therefore, the positioning control operation dominated by the servo circuit system and the data processing operation dominated by the channel signal processing circuit system are time-divisionally operated.

By the way, recently, the development of the magneto-resistive head has been actively developed, and the recording density has been improved by taking advantage of the characteristic that the reproducing efficiency is extremely excellent. Memory density is increasing dramatically.

Accordingly, there is an increasing demand for the development of thinner and smaller magnetic disk devices for the spread of notebook computers and mobile computing applications. In addition, magnetic disk devices, which have been positioned as computer peripherals, have begun to be used in storage devices for in-vehicle navigation systems and have entered new fields as storage devices for entertainment use.

In such applications, not only high-density storage but also lightness and small size are desired as described above. With regard to such various spreads of application fields, demands for impact resistance are being made as severe as those for improving the recording density and reducing the size and weight.

Under these circumstances, the demand for severe recording density improvement expected from the system side and the demand for thinner and smaller magnetic disk drives are accelerating more and more severely.
It is significantly faster than the development speed of the head material and the medium material, which are the main elements of magnetic recording, and is far exceeding the design and development speed of the mechanical components of the magnetic disk drive.

In particular, recently, ultra-thin and ultra-large capacities of small magnetic disk loading have been developed, and PCMCIA-compliant card size magnetic disk devices have been actively developed.

In the development of such a magnetic disk drive,
On the one hand, it aims at large capacity like a magneto-optical disk drive, and on the other hand it aims at high-speed access and high reliability like a semiconductor memory.

As a development policy aimed at the former, steady efforts such as the development of a magnetic head, the development of a magnetic recording medium, and the development of a signal processing method are continued as described above. Regarding the latter, the introduction of new technologies such as improvement of servo performance and mounting of an impact sensor has been considered.

However, it is becoming impossible to cope with the rapid development speed in improving the recording density and the increasingly accelerated improvement in impact resistance only by such steady efforts.

Therefore, it is an important issue how to enable a high-density recording that is robust against external shocks and internal vibrations in a magnetic disk device having a low rigidity and a small rigidity, and has a small signal processing method. Needless to say, the best recording / reproducing characteristics can be ensured by integrating the magnetic head and magnetic disk medium into one, and we studied systematic development including servo performance and even servo information recording method for positioning control. There is a need to go.

[0029]

In the design and development of a conventional magnetic disk drive, in order to provide high-density storage, high-speed access, and high reliability while ensuring the storage and restoration of information, first, sufficient In order to satisfy the recording / reproducing characteristics in the linear direction, which is the traveling direction of the magnetic head, the recording / reproducing ability of the magnetic head must be improved so that the amplitude characteristics related to the magnetic recording characteristics can be extended to the highest possible bandwidth. Magnetic recording media have been reduced in noise.

Thereafter, the track pitch is determined in the track direction, which is the radial direction of the disk-shaped magnetic disk, so that the mutual data interference between the tracks at adjacent positions does not affect the system construction. I do.

For this reason, the geometrical and effective lengths of the magnetic head such as the size of the magnetic head, the recording track width, and the reproducing track width are determined. Is determined. There are various approaches to the determination of the recording density of the magnetic disk drive, but such a measure is generally taken.

Conventionally, the required specification for the servo positioning accuracy is calculated at the same time when the recording density is determined. At this time, only when the servo system can secure the positioning accuracy,
The configuration is established as a magnetic disk device under a predetermined error rate.

On the other hand, with respect to providing high-speed access and high reliability, the throughput is improved by increasing the speed of the spindle motor, the high positioning accuracy is ensured by expanding the positioning control band, and the external impact force is increased by adding an anti-impact sensor. Studies have been made on recording unnecessary signals and avoiding erasure of valid data.

By the way, the magnetic disk drive is becoming lighter and thinner and smaller, and the field of use of the magnetic disk drive is expanding to the application areas that are easily affected by external impacts, such as mobile computer peripheral storage devices, vehicle-mounted types, and entertainment device mounted types. . In these fields, not only the storage capacity but also the above-mentioned problems inherent in movable storage devices such as high impact resistance and high reliability have been focused.

For these reasons, the role of the servo system is becoming larger than before, and the ratio of the improvement in the positioning accuracy and the improvement in impact resistance is very large. For this reason,
The servo band has been increased by about 1.5 to 2 times the conventional one, and efforts have been made to further improve the positioning accuracy. At the same time, instead of adding an impact sensor only in the direction of access to the magnetic head, research and development to deal with spatial impact forces by adding it in three directions, perpendicular to the plane of access and perpendicular to the plane of access. Has also been made.

However, it is very difficult to further expand the servo band only by leveraging the servo system, the cost of the shock sensor is increased, and the cost of the magnetic disk device including the development cost is increased. Not only does it go against the demands for realization, but there are also a number of major issues regarding the application of impact forces to servo systems, such as the need to construct complex servo systems.

What is problematic in terms of impact resistance is how to deal with the magnetic disk device when it is not operating, when it is reproducing, and when it is recording. At the time of non-operation, mainly mechanical approaches such as a magnetic head, a problem of mutual interference between magnetic disks, and a configuration of peripheral mechanical parts are mainly used, and this method is best.

However, the latter problem is a problem as a device including a servo system. The problem of vibration and shock during this operation can be recovered by retrying the positioning control of the magnetic head during the reproducing operation, but the throughput for a high-speed access request naturally deteriorates. When an impact is applied during the recording operation, only a measure is taken to prevent unnecessary signal recording in an area other than the predetermined position mainly by cutting the recording operation.

However, when a vibration disturbance that cannot be detected by the shock sensor is applied, the disturbance is recorded on the magnetic disk in a state where the disturbance is mixed with the recording signal data, which impairs the reliability of the data. Leads to

Therefore, in a magnetic disk drive that is reduced in size and weight, it is a very important issue how to configure a robust servo system even with a low-rigidity housing.
Rather than relying solely on the approach from the mechanical servo system alone, grasp the various characteristics of magnetic recording, and through the entire system configuration, systematically include the servo information recording method and format related to the servo information quality. An approach is required. Therefore, an object of the present invention is to improve the recording efficiency of an ultra-thin magnetic disk drive, to effectively prevent servo performance degradation due to internal and external vibrations and external shocks, and to improve format efficiency. Another object of the present invention is to provide a magnetic disk drive capable of effectively coping with a significantly improved impact resistance, including a method of writing servo information.

[0041]

SUMMARY OF THE INVENTION The present invention relates to an ultra-high-density, light-weight, small-sized magnetic disk drive, which has high reliability and high stability even when the device housing has a low rigidity and the possibility of disturbance is large. In addition to realizing positioning control that enables high robustness, the dynamic range of positioning control can be expanded under a narrow track pitch, and linear positioning control over a wide range can be performed. Enables a narrower track pitch. It is another object of the present invention to provide an ultra-high-density magnetic disk device capable of sufficiently withstanding external shocks or the like by performing positioning control at the time of a recording operation, thereby preventing disturbances during the recording operation. In order to achieve this, the present invention provides a magnetic layer in which tracks on the surface layer are used for data recording / reproducing and tracks on the deep layer are used for positional information on the front and back surfaces so as to have a positional correspondence. At least one magnetic disk which records the position information of the recording / reproducing track at a corresponding track position on the other surface side in correspondence with the data recording / reproducing track, and uses it as the position information of the recording / reproducing track. , Disposed opposite each other via the magnetic disk,
Reads position information or data recorded on the magnetic disk, and a pair of recording / reproducing separation type magnetic heads for recording data, of the pair of magnetic heads,
Means for specifying the position of a recording / reproducing track based on the position information read / reproduced by one magnetic head and controlling recording or reproduction of data with the other magnetic head of the pair of magnetic heads And was configured.

The track for position information is divided into a plurality of track widths, and position information is recorded on the divided tracks at different frequencies, and the position information at each different frequency is separated by frequency. By extracting the mutual error and correcting the position of the magnetic head from the error, the positioning accuracy of the magnetic head is improved.

A feature of the present invention is that, conventionally, a recording area for user data is provided next to the servo information, and no track positioning control is performed at the time of recording / reproducing the user data. Is characterized in that the track positioning control is always performed simultaneously at the time of data recording and reproduction.

Therefore, in the apparatus of the present invention, the recording layer of the magnetic disk is provided not only in the surface layer but in two or more layers, and the servo information is provided over the entire surface of the magnetic disk in the deep layer so that it cannot be erased by normal recording and reproduction. To record and reproduce data on the surface layer. Further, when the data on the surface layer is accessed by a magnetic head, the data to be processed is recorded in a deep portion of the magnetic disk surface opposite to the magnetic disk surface on which the target data exists, and the same data is read using servo information. Reproduction is performed by a magnetic head disposed on the opposite surface, and positioning control is performed. Based on this positioning control, recording / reproduction of the target data surface is performed by positioning control on the same half-facing positioning track.

Further, the servo operation and the signal processing operation for data are performed independently, and a configuration is adopted in which positioning control is performed even when data is recorded. At this time, at least two recording / reproducing amplifiers are in a movable state, and one of the individual amplifiers is used for data recording / reproducing, and the other is used for servo positioning. Further, among the servo information, the positioning control information is recorded on a servo track that is equal to or less than a predetermined track pitch and is 1 / integer of the track pitch, and the positioning control signal recorded on an adjacent servo track is a frequency separating means. Thus, it is possible to separate and extract, and the positioning is performed within the track pitch using the amplitude value, and detailed positioning control is performed at the servo track pitch interval.

The present invention has the following excellent functions and effects due to the above-described configuration. First, in realizing an ultra-high-density magnetic disk drive, it is possible to build up a high-suppression of external and internal vibrations due to a decrease in rigidity of the housing, which is a problem in miniaturization, and to build a robust positioning control system against external shocks. In addition, even during normal user data recording, a recording operation can be performed with the positioning control being performed. Therefore, the possibility that external asynchronous noise mixed during recording, for example, an asynchronous vibration component of the spindle motor, is included in the recording data is extremely reduced, and the positioning control of the magnetic head is performed with a predetermined positioning accuracy during recording and reproduction. Becomes possible. Further, since the servo method using the frequency separation means is used, the quality of the servo information is greatly improved, the positioning accuracy can be further improved, and the design of a high track pitch is facilitated. Also, in writing servo information by the servo information writing device, it is possible to use a simple pattern for the positioning control information.
The development cost of the servo information writing device is reduced, and as a result, the development of the magnetic disk device is accelerated.

Further, since the servo system and the signal processing system are configured independently and in parallel, it is not necessary to rely on a complicated sequence. Furthermore, since the information used in the servo system is recorded in the deep portion of the magnetic disk surface opposite to the magnetic disk surface on which the information used by the user data signal processing system is recorded, the servo information is reproduced. Even when the recording operation of the user data is performed, there is no mutual interference problem, and an excellent effect that good performance can be ensured in each system.

[0048]

A feature of the present invention is that a recording area for user data is provided next to servo information, and no track positioning control is performed at the time of recording / reproducing user data. The magnetic disk device of the above is characterized in that the track positioning control is always performed simultaneously at the time of data recording and reproduction. Therefore, in the apparatus of the present invention, the recording layer of the magnetic disk is provided not only in the surface layer but in two or more layers, and servo information is recorded over the entire surface of the magnetic disk in a deep layer so that it cannot be erased by normal recording and reproduction. Then, data recording and reproduction are performed on the surface layer. Further, when the data on the surface layer is accessed by a magnetic head, the data to be processed is recorded in a deep portion of the magnetic disk surface opposite to the magnetic disk surface on which the target data exists, and the same data is read using servo information. Reproduction is performed by a magnetic head disposed on the opposite surface, and positioning control is performed. Based on this positioning control, recording / reproduction of the target data surface is performed by positioning control on the same half-facing positioning track. Further, the servo operation and the signal processing operation for data are performed independently, and a configuration is adopted in which positioning control is performed even when data is recorded. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIGS. 1 and 2 show a first embodiment in which the present invention is applied to a magnetic disk drive. FIG. 1 shows the first embodiment of the present invention. Among the related system configurations, a block diagram mainly showing an example of a head amplifier peripheral portion is shown, and FIG. 2 schematically shows a system configuration of the present invention.

The present invention provides high reliability and high robustness while securing a large storage capacity in a limited space like a high-density magnetic disk device, particularly, an ultra-high-density light and small magnetic disk device. It is assumed that the magnetic disk device is such that importance is placed on it. Further, the present invention can be sufficiently applied to magnetic disk devices other than the ultra-thin magnetic disk device. In this case, the effect of the present invention is ensured, and this case also belongs to the scope of the present invention. is there.

In FIG. 1, reference numeral 40 denotes a disk-shaped magnetic disk. The magnetic disk 40 is formed by applying a first magnetic material to the surface of a thin disk-shaped base material 40a made of a material such as aluminum or glass. Each surface has a two-layer structure in which a layer 41a is formed, and a second magnetic substance is applied on the surface layer side to form a surface magnetic layer 41b.
Note that the two-layer structure described here is a two-layer structure when classified into a data recording / reproducing layer and a servo layer, and the actual physical magnetic layer is not limited to two layers, but may be a three-layer structure. Four or more layers may be used.

In the example described here, the deep magnetic layer 41a
Is used for recording servo information, and the surface magnetic layer 41b is used for recording data. A plurality of tracks are formed on the surface magnetic layer 41b, and each track is formatted into a plurality of sectors. Each track is formed concentrically with a narrow predetermined track width around the axis of the disk-shaped magnetic disk 40.

The servo information is for obtaining servo positioning control information, and the deep magnetic layer 41a on the opposite side of each surface magnetic layer 41b of the magnetic disk 40 has servo information corresponding to each track of the surface magnetic layer 41b. It is for recording information. Further, in this apparatus, the track for recording servo information has the same track width as the track for recording data, but the track is divided into, for example, 1/4 width and becomes 1/4 width track. The same 1/4 width track records the same servo information, but the servo information is recorded at a different frequency in each track. In a magnetic disk drive, a track servo signal is created from servo information. The track servo signal is an important signal for detecting at which position on the magnetic disk the magnetic head is positioned.

Reference numerals 42a and 42b denote a pair of magnetic heads arranged to face each other with the magnetic disk 40 interposed therebetween. The magnetic heads 42a and 42b are supported by an actuator 43 which moves (seeks) the magnetic heads 42a and 42b on the magnetic disk 40 in the radial direction. Have been. Specifically, the actuator 43 includes an actuator carriage and an actuator arm, and is held on the free end side of the actuator arm. The magnetic head 42a is for the upper surface side of the magnetic disk 40, and the magnetic head 42b is for the lower surface side of the magnetic disk 40, and is for recording and reading data on the magnetic layer.

In the magnetic disk drive of the present invention, the deep magnetic layers 41 a on both sides of the magnetic disk 40 are provided.
Servo information applied in the present invention is recorded in advance in a portion by a dedicated device for writing servo information. In this case, the servo information of the deep magnetic layer 41a is
The data is recorded so as not to be affected by the data recording / erasing operation of the part b.

For this reason, a measure is taken so that the servo information recorded in the deep magnetic layer 41a is not affected by the data recording / erasing operation by utilizing the magnetic characteristics of the magnetic disk used. In the process of writing the servo information to the deep magnetic layer 41a, the application of the conventional technology can be sufficiently considered, and therefore the conventional technology may be used. The deep magnetic layer 41a
The format of the servo information of the unit will be described in detail in the second embodiment.

In the magnetic disk drive of the present invention, the surface magnetic layers 41b on both sides of the magnetic disk 40 are normally used as data recording layers.

In the present embodiment, the deep magnetic layer 41a is used as the servo information recording layer, and the surface magnetic layer 41b is used as the data recording layer. The servo information can be provided in the surface magnetic layer 41b, and the data portion can be provided in the deep magnetic layer 41a, since it is not required to be affected by the data recording / erasing operation. In this case, the signal-to-noise ratio of the data section may be degraded, but the signal processing section can effectively compensate for this. Therefore, this case is also within the scope of the present embodiment.

Reference numerals 42-1 and 42-2 denote magnetic heads.
Each of them employs a recording / reproduction separation type head in which a recording head for data recording and a reproduction head for reproducing the position information and data are separated. The magnetic heads 42-1 and 42-2 of the recording / reproducing separation type are respectively held at the distal ends of actuator carriages (not shown), and are arranged to face each other via the magnetic disk 40. The actuator carriage is attached to one end of an actuator arm (not shown), and the other end of the actuator arm is rotatably supported by a drive mechanism. It is rotatable in a direction along the surface of the disk 40. Therefore, the actuator carriage supported by the actuator arm can move the magnetic heads 42-1 and 42-2 to desired track positions on the magnetic disk 40 with the rotation of the actuator arm. The actuator 43 is a magnetic head supporting / moving mechanism including the actuator carriage, the actuator arm, and the driving mechanism. The actuator 43 allows the pair of magnetic heads 42-1 and 42-2 to be magnetically integrated while maintaining the opposed arrangement state. The disk can be moved to a desired track position.

The magnetic disk drive rotates the magnetic disk 40 by rotating a spindle motor for rotating the magnetic disk 40, which is a magnetic recording medium, in one direction. Information is recorded / reproduced on / from the magnetic disk 40 by the magnetic heads 42-1 and 42-2, which are separate recording / reproducing heads. The magnetic disk 40 has its magnetic layer 41
By magnetically formatting a and 41b, a number of tracks are formed concentrically around the axis of the magnetic disk, and each track is divided into a plurality of sectors, and data is magnetically recorded in sector units. Is done.

44-1 is a preamplifier (preamplifier circuit) for the magnetic head 42-1 and 44-2 is a magnetic head 42-2.
Preamplifier (preamplifier circuit). Preamplifier 4
4-1 has a recording current amplifier 86a and a reproduction amplifier 87a, of which the reproduction amplifier 87a is
The read-out signal of the data reproduced in -1 is amplified and outputted, and the recording current amplifier 86a current-amplifies the signal of the data to be recorded and gives it to the magnetic head 42-1. Further, the preamplifier 44-2 has a recording current amplifier 86
b and a reproduction amplifier 87b. Of these, the reproduction amplifier 87b amplifies and outputs a read signal of data reproduced by the magnetic head 42-2.
Numeral 6b amplifies the current of a data signal to be recorded and gives it to the magnetic head 42-2.

Reference numeral 45 denotes a transmission line distributor, and reference numeral 46 denotes a servo controller. Of these, the transmission line distributor 45
Has a path changeover switch for a plurality of systems (three systems in the example in the figure), and outputs a data signal from the recording system to one of the two recording current amplifiers 86a and 86b, which is designated by the servo controller 46. The path is switched and passed to the reproducing system, and the signal from the reproducing amplifier on one side instructed by the servo controller 46 is selected from the signals from the reproducing amplifiers 87a and 87b. In addition, among the signals (control signal systems) from the reproduction amplifiers 87a and 87b, the distribution is performed such that the path is switched and passed to the servo system so as to select the signal from the reproduction amplifier on one side designated by the servo controller 46. It has a function.

The servo controller 46 controls the rotation drive system for rotating the magnetic disk 40, controls the movement control system of the actuator 43, and controls the preamplifier 44-1.
This is a circuit for performing gain control of 44-2, switching control of the transmission line distributor 45, and the like.

In FIG. 2, reference numeral 50 denotes an automatic gain control type amplifier, which is a transmission line distributor 45 shown in FIG.
, And amplifies and outputs the output of the reproducing system. Reference numeral 51 denotes a recording / reproduction processing unit, which has a reproduction processing system and a recording processing system. Among these, the reproduction processing system is for converting the read data of the magnetic disk obtained through the amplifier 50 into data in a format that can be handled by the host computer, and sending the data as reproduced data to the host computer. The processing system processes the data to be recorded given from the host computer into a readable data format in a recording track, converts the data into a recording signal, and outputs the recording signal to the transmission path distributor 45.

Reference numeral 60 denotes a servo auto gain control amplifier (servo AGC amplifier), 61 denotes a frequency separation processing unit, 62 denotes an error detector, 64 denotes a sector detector, 65 denotes a timing generator, 66 denotes a signal processing servo sequencer,
Reference numeral 68 denotes an actuator driver, 46 denotes a servo controller, and 80 denotes a track servo signal selector (TSS selector).

The servo AGC amplifier 60 amplifies the servo information supplied from the transmission line distributor 45 while controlling the gain, thereby performing a predetermined amplitude value correction and outputting the amplified information. This is to separate and extract the servo positioning information of the predetermined track whose amplitude value has been corrected from the servo information. In the frequency separation processing unit 61, appropriate equalization is performed in order to perform frequency separation extraction. Further, under the control of the servo controller 46, the frequency separation processing unit 61 separates and extracts predetermined frequency signals and performs appropriate amplitude correction. As will be described in detail later, in this apparatus, for each track, for example, the track is divided into four equal parts in the track width direction to form quarter-width tracks, and the same servo information is recorded at different frequencies for each track. Therefore, by frequency-separating each of the servo information based on these four frequencies, the frequency separation processing unit 61 can acquire and output the respective servo information.

The error detector 62 obtains a plurality of types of error detection signals at the current magnetic head position by extracting mutual errors based on the signals separated and extracted by the frequency separation processing unit 61. Things.

TSS (track servo signal) selector 80
Is for selecting and outputting one of the plurality of types of error detection signals based on an instruction from the servo controller 46. For example, the plurality of types of error detection signals are sequentially
This is for selecting and extracting each type at a predetermined timing.

The sector detector 64 detects sector information in the turbo information, receives the output of the servo AGC amplifier 60, detects the sector information from the output, and supplies it to the timing generator 65. It is.

The timing generator 65 receives the sector information, generates a timing signal such as a predetermined servo clock or the like, and supplies the timing signal to the servo controller 46 to perform timing synchronization of the servo information. The servo information can include sector information and track information in addition to the servo positioning control information.

The signal processing servo sequencer 66 includes a recording / reproducing processor 51 and a servo controller 4 for executing a reproducing operation in response to a reproducing operation signal (reproduction command) or a recording operation signal (recording operation command) from the host computer.
The actuator driver 68 receives an actuator control signal 67 from the servo controller 46 and drives the actuator 43 in response to the signal. Is what you do.

Next, the operation of the present embodiment to which the present invention is applied will be described with reference to FIGS.

First, when a reproduction operation signal instructing reproduction is issued from the host computer, the signal processing servo sequencer 66 receiving the signal sends a control signal to the recording / reproduction processing unit 51 and the servo controller 46. Then, in response to this control signal, the servo controller 46 moves the magnetic heads 42-1 and 42-2 to desired positions on the magnetic disk 40.
In order to move the actuator 43 from the current track position to the target track position, an actuator control signal 67 is generated and sent to the actuator driver 68 to drive the actuator 43.

At this time, the servo controller 46 controls the transmission line distributor 45 so that a reproduction signal can be obtained from the magnetic head 42-2 on the back surface of the magnetic disk 40 on which the data requested by the host computer exists. , Generates a backside servo switching signal 69 and supplies it to the transmission line distributor 45. Then, the transmission path distributor 45 receiving this signal switches the switching circuit according to the back side servo switching signal 69. As a result, the servo information is stored in the servo system (servo unit), and the reproduction signal (reproduction data)
Are switched to be sent to the reproduction system (signal processing unit).

As described above, the back side servo switching signal 69
, Predetermined data and servo information can be linked to the servo unit and the signal processing unit, respectively.

At this time, the data does not always match the data requested by the host computer. Here, the positioning control of the servo unit that has received the predetermined servo information is started. Hereinafter, in order to advance the description in detail, the magnetic head 42-1 is used for recording and reproducing data.
It is assumed that the magnetic head 42-2 is used for reproducing servo information. It is assumed that four types of servo positioning control information are employed.

In the servo section, first, the servo information received from the transmission line distributor 45 is input to the servo AGC amplifier 60, where a predetermined amplitude value correction is performed. After this,
The servo positioning information of a predetermined track is sent to the frequency separation processing unit 61 in order to separate and extract the servo positioning information from the servo information. Here, appropriate equalization is performed to perform frequency separation extraction. The frequency separation processing unit 61 separates and extracts predetermined frequency signals under the control of the servo controller 46, and performs appropriate amplitude correction. Thereafter, the separated and extracted signals are sent to an error detector 62, where an error detection signal at the current magnetic head position is obtained.

The error detection signal is operated by a subsequent TSS (track servo signal) selector 80 to select a specific error detection signal in response to an instruction from the servo controller 46. With this configuration, a predetermined temporary track servo signal 81 can be obtained.

The track servo signal is an important signal for detecting where the magnetic head is positioned on the magnetic disk.
1, the servo controller 46 performs appropriate processing on the temporary track servo signal 81, and then associates the temporary track servo signal 81 with the physical position of the magnetic disk, thereby generating a track servo signal. Thereafter, by using the track servo signal, a control signal is sent to the actuator driver 68 so as to move the magnetic head to a track position accessible to data requested by the host computer.

In this manner, a series of feedback control of the servo information, the magnetic head, the track servo signal, the servo controller 46, the actuator driver 68, and the actuator 43 is realized. By controlling the position of the magnetic head with respect to almost the entire circumference, positioning accuracy is improved, and target data and access are performed. On the other hand, as the servo information, "sector information" and "track information" can be provided in addition to the servo positioning control information. In this case, sector detection using "sector information" is performed by the sector detector 64. . When a sector is detected by the sector detector 64, this detection information is sent to a timing generator 65, and the timing generator 65 generates a timing signal such as a predetermined servo clock from the input timing of the detection information. Then, based on the timing signal from the timing generator 65, the servo controller 46 is caused to perform timing synchronization of the servo information. This allows
The improvement of the processing throughput of the servo unit is ensured. When the positioning control is performed in this manner, the magnetic disk is passed through the magnetic head provided on the surface opposite to the magnetic disk surface on which the magnetic head used for the positioning control is provided. And data recording / reproducing can be performed between the two.

Further, since positioning control can be performed even during data recording / reproducing operation, unnecessary vibration components applied at the time of recording can be sufficiently suppressed, and a servo system which is extremely resistant to disturbance can be constructed. Further, since the servo positioning control signal is detected by using the frequency separation means (frequency separation processing unit 61), the signal-to-noise ratio of the servo system is dramatically improved. As a result, the positioning accuracy is improved, and a high-density design that further narrows the track pitch becomes possible.

In this embodiment, four signals are used for the servo positioning information. However, an appropriate number of signals can be used based on the relative relationship between the magnetic head width and the track pitch. In this case, the range from two to six types provides the highest efficiency, but the configuration shown in the present embodiment has versatility not affected by this number.

(Second Embodiment) FIG. 3 shows a second embodiment in which the present invention is applied to a magnetic disk drive. In order to carry out the present invention, depending on the type of servo positioning information to be written (written) into the deep magnetic recording layer 41a,
Its performance is greatly affected. Therefore, a brief description will be given of an embodiment of servo positioning information effective in the present embodiment, an example of a format thereof, and a method of obtaining a servo track signal as positioning information by using servo positioning information according to the present invention. Write.

FIG. 3 is a schematic configuration diagram of the servo information. FIG. 4 is a simplified diagram for obtaining a track servo signal, which is a relationship between a physical position and a voltage signal used for magnetic head positioning control in a servo system.

In this embodiment, based on the first embodiment, four types of patterns are used for the servo positioning control signal to be driven into the deep magnetic layer 41a. As described in the first embodiment, the present invention is not limited to only four types, so that a wide range of applications is possible.

First, a simplified form of the servo information according to the present invention is as shown in FIG. In FIG. 3, reference numeral 100 denotes a sector header portion, and 101 denotes a servo positioning control signal area. Tdp indicates a track pitch (track width),
Sct indicates a unit sector. Sector header part 1
00 is for detecting each sector Sct, and the servo positioning control signal area 101 is an area where servo positioning control signals are recorded. For each track, the servo positioning control signal area 101 is divided into four track pitches Tdp to form a track format of 1/4 width, and servo positioning information is recorded on each track of 1/4 width using a specific frequency different from each other. Is done.

Incidentally, servo information such as an AGC signal, an address code, and a sector detection signal can be embedded in the sector header section 100 for detecting each sector Sct as in the related art. In this case, the conventional technology can be used.

Subsequent to the sector header section 100, there is a servo positioning control signal area 101 in which a servo positioning signal is embedded up to the boundary position of the next sector header section 100.
It is also possible to provide a “separation signal portion” at the end of the servo positioning control signal corresponding to a position before “0” to clarify the separation position. However, in this embodiment, this signal is not added.

The servo positioning control signal is sent to the deep magnetic layer 4
Although written in the portion 1a, as shown in FIG. 3, servo tracks are recorded at a different pitch from the track pitch at which the user data 56 can be recorded and reproduced.

In the present embodiment, as described above, a 4-track parallel arrangement with a track width of "servo track pitch = track pitch / 4" is employed.
The four tracks in the parallel arrangement have a format in which servo information is recorded at a different frequency for each track. That is, as shown in FIG. 3, the track pitch Tsp of the servo track is set to Tdp / 4 with respect to the track pitch Tdp of the data track, and each data track is adjacent to the adjacent track 4 at a position corresponding to the data track.
The servo tracks F1, F2, F3, and F4 are used for recording a servo positioning control signal for the data track. Four adjacent servo tracks F1, F2, F3
In F4, the same servo positioning information is recorded at different frequencies.

With this configuration, it is possible to control the data tracks with an accuracy of 1/4 track pitch interval when performing positioning control.

Further, the problem of the reduction of the dynamic range which occurs when the magnetic reproducing head width is narrow or wide with respect to the track pitch is solved. Further, by finely chopping the servo track pitch, it is possible to perform control with increased track resolution. In the servo positioning control, on-track control is performed in the middle of each servo track. Therefore, it is possible to perform positioning control anywhere between tracks by changing the off-track amount.

[0093] As for the servo track setting method, as shown in the present embodiment, the servo tracks are finely set in one track, and the servo tracks are written in the servo tracks used when on-track control is performed. The configuration is such that the signal component exists only within the reproduction width of the reproduction head. With this setting, the separation and extraction of the servo tracks by the frequency separation means can be easily performed.

Even in the case where the above-mentioned one does not exist,
It is also possible to realize this by configuring an additional circuit in the separation and extraction means, and this is positioned as an application example of the present embodiment. For the signal component recorded on the servo track, a pattern that can easily perform frequency separation and extraction and improve the signal-to-noise ratio is selected.

In this embodiment, a repetition signal is selected, and FIG.
"F1" to "F4" are recorded as shown in FIG.

By recording servo information with the above-described configuration, positioning control at the time of user data recording, which has been impossible in the past, can be performed. Further, except for the sector head, most servo positioning control signals are used. Is written, the effect of dramatically improving positioning accuracy and high durability can be secured.

Further, as an application example of the present embodiment, by excluding sector headers, information on sectors and the like are included in the surface magnetic layer portion 41b which is a data area.
Positioning control can be performed in a state close to perfect positioning control, and ultimate servo positioning control can be realized.

FIG. 4 shows a method of generating a track servo signal required when the servo system performs positioning control.

In the figure, reference numeral 200 denotes a reproducing head, which shows a state in which there is a slight displacement with respect to the data track. Tdp indicates a data track pitch, and 200Aj indicates a reproducing head positioned with respect to the data track.

Here, the reproduction head 2 having a position shift is described.
A case will be described in which the positioning control is performed for the state 00 in the state of 200 Aj. As shown in the first embodiment,
From the frequency separation extractor 61, each servo track F1, F
2, F3 and F4 are "Fo1" and "F
o2 "," Fo3 "," Fo4 ", etc. 201 is a diagram showing the output result in the track direction (track pitch direction).

Thereafter, the frequency separation / extraction output of 201 is input to the error detector 62, and the error detector 62 generates an error signal 202 between adjacent tracks. The error signal detector 62 calculates the difference between Fo1 and Fo4 by using Fo1-F
An error detector for o4, an error detector for Fo2-Fo1 that takes the difference between "Fo2" and "Fo1" that takes the difference between "Fo2" and "Fo1", and a Fo3 that takes the difference between "Fo3" and "Fo2"
There are an error detector for Fo3, an error detector for Fo4 and Fo1 that takes the difference between “Fo4” and “Fo1”, and these are “Fo1 and Fo4”, “Fo2 and Fo3”, and “Fo4”.
And Fo1 ″. These four types of error detection outputs are TSS (track servo signal).
The data is input to the selector 80. Then, under the control of the servo controller 46, the track servo signal selector 80
Selects and extracts these four types of error detection outputs one by one at predetermined time intervals in order, thereby obtaining “F
o21 "," Fo32 "," Fo43 "," Fo14 "
Is obtained.

Here, “Fo21” is replaced by “Fo1” and “F
o4 ”is a temporary track servo signal obtained from the error signal due to“ Fo2 ”and“ Fo1 ”, and“ Fo21 ”is a temporary track servo signal obtained from the error signal due to“ Fo1 ”.
“o32” is a temporary track servo signal obtained from an error signal based on “Fo3” and “Fo2”, and “Fo43” is a temporary track servo signal obtained from an error signal based on “Fo4” and “Fo3”.

The servo controller 46 converts the sequentially extracted and outputted temporary track servo signal 203 into a continuous track servo signal, and generates a track servo signal indicating a "position-to-voltage" relationship from this. Further, the servo controller 46 obtains a correction amount such that the center of the magnetic head is located at the center of the data track based on the track servo signal, and outputs an actuator control signal 67 having a correction corresponding to the correction amount. Give to 68.

As a result, the actuator driver 68 controls the actuator in accordance with the actuator control signal 67, and the position of the magnetic head at the tip of the actuator is controlled so that its central part is located at the center of the track position. Become.

As described above, the current position of the magnetic head can be confirmed from the servo information and the servo positioning control signal.
The operation amount is transmitted from the servo controller 46 to the actuator 43, and the position is corrected by performing feedback control, and the magnetic head 20 is moved to a target position.
0 means that the positioning is controlled.

As can be seen from the present embodiment, the positioning of the magnetic head can be controlled continuously over all tracks by efficiently connecting the temporary track servo signals. At the same time, the problem relating to the dynamic range degradation of the servo track signal, which has been raised as a problem by the set number of each servo track, is solved.

As described above, the present invention provides high reliability, high stability, and high robustness in an ultra-high-density, light, thin, and small magnetic disk device even when the device housing has a low rigidity and there is a large possibility of disturbance. In addition to realizing the positioning control, the dynamic range of the positioning control can be expanded under the narrow track pitch, and the linear positioning control over a wide range is enabled, so that the narrow track pitch indispensable for high density recording Enable. It is another object of the present invention to provide an ultra-high-density magnetic disk device capable of sufficiently withstanding external shocks and the like by performing positioning control during a recording operation to prevent disturbances during the recording operation. In addition, two magnetic layers are formed respectively, and a plurality of tracks are formed in each layer so as to have a positional correspondence between the front and back surfaces. The tracks for recording / reproducing and the second layer are used for position information, and the position information of the recording / reproducing track is recorded at a corresponding track position on the other surface corresponding to the data recording / reproducing track on one surface. At least one magnetic disk for recording and reproducing track position information,
A pair of separated recording / reproducing magnetic heads, which are arranged to face each other via the magnetic disk, read position information or data recorded on the magnetic disk, and record data, and the pair of magnetic heads; Of the heads, the position of a recording / reproducing track is specified based on the position information read / reproduced by one magnetic head, and data is recorded or reproduced by the other magnetic head of the pair of magnetic heads. And means for controlling to perform

Further, the track for position information is divided into a plurality of track widths, and position information is recorded on the divided tracks at different frequencies, and the position information at each different frequency is frequency-separated. By extracting the mutual error and correcting the position of the magnetic head from the error, the positioning accuracy of the magnetic head is improved.

The major point of the present invention is that a magnetic disk drive according to the present invention conventionally has a recording area for user data next to servo information and does not perform any track positioning control at the time of recording and reproducing user data. Is characterized in that the track positioning control is always performed simultaneously at the time of data recording and reproduction.

That is, the magnetic disk drive of the present invention
At least two recording layers are provided on each surface of the magnetic disk on which data is recorded. Of these, for example, the recording layer on the surface layer side is used for data recording and reproduction, and the recording layer on the deep layer side is used for servo. . The data recording / reproducing operation is for recording / reproducing a data recording / reproducing track on one surface of the magnetic disk, and the servo positioning control is performed according to the servo positioning information recorded on the track on the deep recording layer on the opposite surface of the magnetic disk. At the same time, data recording / reproducing is performed on tracks of the magnetic layer on the surface layer on one surface of the magnetic disk. That is, in the magnetic disk drive of the present invention, the servo positioning control is simultaneously performed during data recording / reproduction. In addition, servo positioning information is provided on each of tracks in which a simple pattern that can be frequency-separated is divided by a pitch width of about 1 / integer of a predetermined track pitch, and fine movement in a predetermined track of the reproducing head is separated and extracted by each frequency. This is performed based on the difference in the position control signal amplitude. The servo positioning control operation is performed when recording user data (when recording data on a track on the surface layer side recording layer).
A configuration that can be implemented also in is adopted.

As a result, various external and internal vibration factors such as a reduction in rigidity of the device housing due to a reduction in the size and weight of the magnetic disk device, a deterioration in positioning accuracy and a reduction in reliability due to the effects of external shocks and internal / external disturbances. Even if it occurs, the magnetic head positioning control can be performed with high accuracy while maintaining sufficient suppression characteristics. , The track pitch can be narrowed. In addition, positioning control is also performed during user data recording, so that disturbance vibration components, which are highly likely to be mixed into recording data during recording, can be significantly suppressed by this positioning control, and the quality of servo positioning information can be significantly reduced. Therefore, a highly reliable magnetic disk drive can be configured.

Further, since there is no shortage of the dynamic range of the servo positioning control signal in an extreme wide read system or a narrow read system due to the use of a magnetoresistive head or the like, stable positioning control is possible. Various effects as described above can be realized.

The present invention is not limited to the above specific examples, but can be implemented with various modifications.

[0114]

As described above, in the magnetic disk drive to which the back side deep servo positioning control according to the present invention is applied, the rigidity of the device housing is reduced due to the reduction in size and size of the magnetic disk drive, and external shocks and external and internal shocks occur. Even if there are concerns about the effects of various external and internal vibration factors such as deterioration of positioning accuracy and reliability due to the influence of disturbance, positioning control of the magnetic head is possible while maintaining sufficient suppression characteristics. Therefore, sufficient reliability can be ensured even when employed in a movable storage device. In addition, servo information and user data are provided independently in a deep portion and a surface portion of the magnetic disk surface. Further, when positioning control is performed on an arbitrary magnetic disk surface, the user data is provided on the opposite surface of the magnetic disk. Is performed, the servo operation and the signal processing operation can be performed independently and in parallel. Therefore, positioning control can be performed even during user data recording, and disturbance vibration components mixed during recording can be extremely suppressed, so that a highly reliable magnetic disk device can be configured. In addition, a simple recording signal is recorded in the deep portion of the servo positioning information, and the ratio of the positioning control information in the sector is much larger than that of the conventional magnetic disk drive. As a result, the quality of the servo positioning information is greatly improved, and as a result, the positioning accuracy is remarkably improved, so that the track pitch of the magnetic disk device can be reduced. In addition, since a servo track pitch smaller than a predetermined track pitch is provided and positioning control is performed based on the servo track, the linear range of the control dynamic range required for the servo positioning control is expanded, and the conventional saturation Since no phenomenon occurs, an excellent operation and effect can be obtained such that an excellent linear positioning control system can be configured.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining the present invention, and is a block diagram mainly illustrating a configuration example of a magnetic disk peripheral portion and a head amplifier peripheral portion in a system configuration according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the present invention, and is a schematic configuration diagram of an example of a main system configuration according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining the present invention, and is a diagram for explaining a schematic configuration of servo information according to a second embodiment of the present invention.

FIG. 4 is a diagram for explaining the present invention, and shows a relationship between a physical position and a voltage signal used for magnetic head positioning control in a servo system according to a second embodiment of the present invention; FIG. 4 is an explanatory diagram of a process of obtaining a servo signal.

FIG. 5 is a perspective view of a general small magnetic disk drive, showing a structure in a state where a top cover is opened and a state where a top cover 34 is closed.

FIG. 6 is a view for explaining a schematic configuration of a format per sector of the small magnetic disk device and a state of each gate signal in a servo circuit.

[Explanation of symbols]

Reference numeral 40: disk-shaped magnetic disk 40a: thin disk-shaped base material 41a: deep magnetic layer 41b: surface magnetic layer 42a, 42b: magnetic head 42-1, 42-2: magnetic head 43: actuator 44-1: magnetic head Preamplifier (preamplifier circuit) 44-2 for magnetic head 42-2 Preamplifier (preamplifier circuit) for magnetic head 42-2 86a, 86b Recording current amplifier 87a, 87b Reproduction amplifier 45 Transmission path distributor 46 ... Servo controller 50 ... Auto gain control type amplifier 51 ... Recording / reproducing processing unit 60 ... Servo auto gain control amplifier (servo AGC amplifier) 61 ... Frequency separation processing unit 62 ... Error detector 64 ... Sector detector 65 ... Timing generator 66 ... signal processing servo sequencer 68 ... actuator driver 80 ... track Servo signal selector (TSS selector) 100: sector header section 101: servo positioning control signal area Tdp: track pitch (track width) Sct: unit sector.

Claims (6)

[Claims] 1. A magnetic layer having a surface layer track for data recording / reproducing and a deep layer track for position information is formed so as to have a positional correspondence on both front and back surfaces, and a data layer on one side is formed. At least one magnetic disk for recording position information of the recording / reproducing track at a corresponding track position on the other surface side in correspondence with the recording / reproducing track to obtain the position information of the recording / reproducing track; A pair of separate recording / reproducing magnetic heads, which are arranged to face each other via a magnetic disk, read position information or data recorded on the magnetic disk, and record data; and Of the pair of magnetic heads, the position of the recording / reproducing track is specified based on the position information read / reproduced by one of the magnetic heads. Magnetic disk apparatus characterized by comprising, a means for controlling so as to record or reproduce data with de. 2. The magnetic disk according to claim 1, wherein the track is divided into a plurality of sectors, and the position information includes sector information. 2. The control device according to claim 1, further comprising control means for performing synchronization in accordance with sector information obtained from position control information recorded in a deep part of the surface, and recording and reproducing data at an arbitrary sector position. Magnetic disk drive. And means for controlling the positioning of the magnetic head with respect to the magnetic disk, and data processing means for simultaneously performing data recording and reproduction while continuously performing the positioning control. The magnetic disk drive according to claim 1, wherein the magnetic disk drive is implemented. 4. A recording / reproducing amplifier is provided for each of said one magnetic disk so as to correspond to each of a pair of magnetic heads arranged via the disk surface.
When one recording / reproducing amplifier is used for reproducing the position control information recorded in the deep portion, the other recording / reproducing amplifier is provided with recording / reproducing means for performing reproduction control so as to be used for recording / reproducing data. 4. The magnetic disk drive according to claim 1, wherein: 5. A positioning control signal recorded in a deep portion is divided into servo tracks having a track pitch width of 1 / integer of a predetermined track pitch of a magnetic disk drive between sectors, and the divided servo tracks are 3. The magnetic disk drive according to claim 2, wherein recording is performed at a recording frequency that can be completely separated from each other by frequency separation. 6. A frequency separating means for separating a positioning control signal recorded on each track on the basis of a positioning control signal recorded in a deep portion, and a frequency separating means for separating each frequency by the frequency separating means. Means for generating a corrected positioning signal based on the error of the positioning control signal for the magnetic head and controlling the positioning of the magnetic head. The frequency separating means separates and reproduces the positioning control signal recorded on a predetermined servo track. 6. The magnetic disk drive according to claim 5, wherein the positioning signal is corrected based on the error to control the positioning of the magnetic head at a predetermined track pitch or less.