JPH0373478A - Magnetic disk device and magnetic head positioning method - Google Patents

Abstract

PURPOSE:To read/write data while positioning control for eliminating the off- track of data heads is carried out by providing a magnetic head with a head part exclusively used for the data reading/writing and a head part exclusively used for reading a servo signal. CONSTITUTION:By setting an interval l2 between the two head parts 19a and 19b to be the integral multiple of an interval l1 among the data signal tracks 18, the other head part is always tracked on whenever one of the head parts is tracked on the data signal track 18. Consequently, by always allowing the one head part to read out the servo signals of the servo signal tracks 17a and 17b, and controlling the position of the magnetic head 4d so that the one head part is tracked on the data signal track 18, the other head part is always tracked on. Thus, the on-track of the magnetic head 4d and the data reading/ writing can be concurrently controlled, and the off-track is eliminated during the data reading/writing period.

Description

[Detailed Description of the Invention] [Summary] Regarding a magnetic disk used as a file device in a computer system, it is possible to completely on-track the data disk 1', and therefore, the track density is high, the storage capacity is high, and high-speed access is possible. With the aim of realizing a magnetic disk device, seek control of the magnetic head is performed based on servo signals recorded on the servo surface, and then servo control of the servo signal track recorded at a specific position on the data signal track of the data surface is performed. In a magnetic disk device that corrects and controls the position of a magnetic head based on a signal, a magnetic head that traces a data surface is provided with two head sections, and the spacing between the two head sections is equal to the spacing of data signal tracks. an integer multiple, and one of the data surface magnetic heads is used exclusively for reading/writing data on the data signal track, and the other head is used exclusively for reading the servo signal track. do.

[Industrial application field]

The present invention relates to a magnetic disk used as a file device in a computer system, and a magnetic head positioning method for the magnetic disk device.

The demand for smaller size, higher speed, and higher storage capacity of magnetic disk devices is increasing, and along with this, the track density and recording linear density of magnetic disk media are also becoming higher.

Therefore, high-speed and high-precision positioning control of the magnetic head is also required.

[Conventional technology]

(1) Overview of the magnetic disk drive and magnetic head positioning mechanism A magnetic disk drive magnetically records data via a magnetic head onto a magnetic disk medium that rotates at high speed. It is attached to a spindle and used to obtain the required storage capacity.

On the other hand, the position of the magnetic head facing each magnetic disk medium is controlled based on a servo signal recorded on the magnetic disk medium, and data is read/written to a predetermined position on the magnetic disk medium. .

FIG. 4 is a block diagram illustrating the outline of the magnetic head positioning mechanism.

A spindle motor 3 rotates a magnetic disk medium 1a+lbllc attached to a spindle 2, and also drives data heads (magnetic heads) 4a, 4b, 4c and a servo head (M1 head) 5 via a support spring 6. By fixing the data heads 4a to the drive arm 7 and driving the carriage 8 with the actuator 9,
4b, 4c and the servo head 5 are positioned all at once.

In addition, the positioning control involves reading and seeking the servo signal recorded on the magnetic disk medium 1c with the magnetic head 5, and then transmitting the servo signal recorded at a specific position of the data signal track of the data magnetic disk medium 1a, Ib. The data heads 4a, 4b, and 4c read out the data and finely adjust the position.

The fine adjustment of the positions of the data heads 4a, 4b, and 4a is performed to correct and eliminate the off-trunk of the data heads 4a+4b, 4c caused by temperature changes in the magnetic disk drive or whirling of the spindle.

(2) Positioning procedure and control of the magnetic head In FIG. 4, the position detection circuit 10 is a circuit that detects the position of the servo head 5 from the servo signal read by the servo head 5, and the detection result is sent to the control circuit. Send it to 11.

The switch circuit 13 connects the output of the data controller 4a to the fine position detection circuit 12 and the data R/W circuit (i%
The switch circuit 13 is controlled by the control circuit 11.The switch circuit 13 is used for all data heads 4a, 4b.
, 4c, but only the data head 4a is shown in the figure.

The fine position detection circuit 12 is a circuit that detects the position of the data head 4a from the servo signal in the data track, and sends the detection result to the control circuit 11.

The control circuit 11 is a circuit that controls the positioning of the data heads 4a, 4b, 4c and the servo hand 5 at the positions specified by the positioning address signal 14, and
The drive control of the actuator 9 is performed based on the output of the position detection circuit 10 and the output of the fine position detection circuit 12, which indicate the current positions of the actuators b, 4e, and 5.

Next, a series of operations of these positioning mechanisms will be explained.

FIG. 5 is a diagram explaining the positioning procedure and data reading/writing of the magnetic head. (a) is a flowchart showing the procedure, and (b) is a diagram showing the time allocation of each procedure.
This is a diagram.

(2) The seek control circuit it drives the actuator 9 from the positioning address signal 14 and the output of the position detection circuit IO, and seeks the data heads 4a, 4b, 4c and the servo head 5 to predetermined positions.

Further, the required time in this case is tl.

(2) The correction control circuit 11 drives the switch circuit 13 and connects the output of the data controller 4a to the fine position detection circuit 12. Then, the actuator 9 is driven from the output of the fine position detection circuit 12, and the data head 4a is
Fine-tune the position and correct it.

Further, the required time in this case is (1).

(2) The read/write control B circuit 11 switches the switch circuit 13 to the R/W circuit side. After that, the R/'W circuit reads/writes data.

Further, the required time in this case is i.

This completes a series of operations, including 1. +tt
+ta time is required.

Next, how the off-track of the data head is corrected and eliminated by the @adjustment will be explained.

FIG. 6 is a diagram explaining the actual fine adjustment of the magnetic head position, (a) is a diagram explaining each area of the data magnetic disk medium, and (b) is a diagram illustrating the servo signal track provided in the servo signal recording area. (c) is a diagram showing the output signal waveform when the data head traces the servo signal track.

For example, as shown in FIG. 2(a), a servo signal recording area 15a is located at a specific position on the data magnetic disk medium 1a, lb.
, ], 5b, 15c, 15d, 15e, 15
There are data signal recording areas 16a and 1 between the recording areas.
There are 6b, 16c, 16d, 16e, and 16f.

Then, as shown in the same figure (b), the servo signal recording area 1
5a, i5b, 15c, 15d, 15e, 1
5f, servo signal tracks 17a each given an equal amount of offset with respect to the data signal track 1B.
and 17b, and the servo signal tracks 17a, 1
7b is traced by the data heads 4a, 4b, and 4c, the magnitude of the output signal obtained from the servo signal track 17a and the servo signal track! Output obtained from 7b (from the size of No. 8, the data heads 4a, 4
The positions of b and 4c are being determined.

That is, data head 4 a + 4 b + 4
c is on-trunk to the data signal track 18, as shown in FIG.
The output signal amplitude ILA obtained from the servo signal track 7a and the output signal amplitude B obtained from the servo signal track 17b are completely different.

However, when the data heads 4a, 4b, and 4c off-track to the servo signal track 17a side, the output signal amplitude becomes A>B, and when the data heads 4a, 4b, and 4c off-track to the servo signal track 17b side, A<8. .

Therefore, by controlling the positions of the data heads 4a, 4b, 4c so that the output signal amplitude A=8, the data heads 4a, 4b, 4c are moved to the data signal track 1.
It can be completely on-track on 8.

[Problems to be Solved by the Invention] However, the above-described magnetic disk device and its magnetic head positioning method have the following problems.

(2) The fine adjustment period for the positions of the data heads 4a, 4b, 4e and the data read/write period are independent, and it is not possible to correct off-track that occurs during the data read/write period.

(2) In order to prevent interference with adjacent tracks caused by the off-track described in (2) above, it is not possible to increase the data track density.

(2) Data cannot be read/written during the period when the data heads 4a, 4b, 4c are reading the servo signal tracks 17a, 17b, that is, during the period when the positions of the data heads 4a, 4b, 4e are being finely adjusted. Therefore, the access time increases accordingly.

The technical problem of the present invention is to solve the above-mentioned problems in conventional magnetic disk drives, and to constantly monitor the position of the data head on the data track, thereby making it possible to completely on-track the data head. The object of the present invention is to realize a magnetic disk device with high trunk density, high storage capacity, and high-speed access.

[Means to solve the problem]

FIG. 1 is a diagram explaining the basic principle of the present invention.

The present invention is characterized in that a magnetic head for tracing a data magnetic disk medium is provided with a head section exclusively for reading/writing data and a head section exclusively for reading servo signals.

That is, the seek control of the magnetic head is performed based on the servo signal recorded on the servo surface, and then 7, the servo signal is recorded at a specific position on the data signal track 18 on the data surface.]・Rack! ? In a magnetic disk device that corrects and controls the position of the magnetic field based on servo signals a and 17b, the magnetic head 4d that traces the data surface is provided with two head portions 19a and t9b, and! f The positive electrode between the two head parts 19a and 19b is connected to the data signal track 1.
The spacing is an integral multiple of the spacing ffi of 8, and one of the heads of the data surface magnetic head 4d is used exclusively for reading/writing data on the data signal trunk 18, and the other head is used exclusively for reading/writing data on the data signal trunk 18. The servo signal tracks 1a and 17b are used only for reading.

[Effect]

By making the interval 12 between the two head parts 19a and 19h an integral multiple of the interval 11 between the data signal tracks 18,
When one head section is on-track to the data signal track 18, the other head section is also sure to be on-track.

Therefore, one head section always reads the servo signals of the servo signal tracks 17a and i7b! -, By controlling the position of the magnetic head 4d so that the head section is on-track on the data signal track 18, the other head section can also be kept on-track at all times.

As a result, on-track control of the magnetic head 4d and data read/write control can be performed simultaneously in parallel, and off-track during data read/write periods can be eliminated. I can do it.

〔Example〕

An example will be used to explain how the magnetic disk device and magnetic head positioning method of the present invention are actually implemented.

(1) Structure FIG. 2 is a diagram illustrating an embodiment, in which (a) is a perspective view of a thin film magnetic head, and (b) is a block diagram illustrating a magnetic head positioning mechanism.

In the thin AM head, the windings and core of the head are formed using lithography techniques.

Therefore, as shown in FIG. 1n(a), the distance 1 between the thin film head portions 21a and 21b formed on the core slider 20 is
1 can be created with high precision.

The thin Y magnetic/rad is used in the data heads 4e, 4f, and 4g shown in FIG. 4(b).

The switch circuit found in conventional magnetic disk drives is no longer required, and the data-only head section of the data head 4a can be used for R/W.
circuit, and connect the servo-dedicated head section to the fine position detection circuit 12a.

Although all the data heads 4a, 4b, and 4c are connected to the fine position detection circuit 12a, only the data head 4a is shown in the figure.

Therefore, the control circuit 11a can always monitor the output of the position detection circuit 10 and the output of the fine position detection circuit 12a, and perform drive control of the actuator 9.

(2) Head positioning means and control Figure 3 is a diagram explaining the magnetic head positioning procedure and data reading/writing, where (a) is a flowchart showing the procedure, and (b) is a diagram for each procedure. FIG.

The positioning method of this embodiment operates as follows.

(2) The seek control circuit 11a drives the actuator 9 from the positioning address signal 14 and the output of the position detection circuit 10, and seeks the data heads 4e, 4f, 4g and the servo head 5 to predetermined positions.

Further, the required time in this case is t.

(2) Correction and data read/write control circuit 11 drives actuator 9 from the output of fine position detection circuit 12 to finely adjust and correct the position of data head 4e.

On the other hand, at the same time, the R/W circuit reads/writes data.

Further, the required time in this case is [4].

This completes the series of operations, and it only takes (,+(4) time for the operations.

(3) Access time and track density As shown in this example, data reading/writing and off-track correction of the data head can be performed simultaneously, so the data head can be completely on-track while Data can be read/written.

As a result, even if the track spacing is narrowed, a reduction in read output due to off-track, crosstalk from adjacent tracks, and data destruction in adjacent tracks will not occur, and it is possible to further increase the track density.

Moreover, the time 11 required for fine adjustment of the magnetic head position before reading/writing data is no longer necessary, and the access time can be shortened accordingly.

For example, with a conventional track width of 8 μm, there are 2
Although a buffer width of ~3μ was provided, the present invention eliminates the need for this buffer width, making it possible to increase the track density by about 20 to 30%. Therefore, storage capacity also increases.

Further, when the rotational speed of the magnetic disk medium is 3600 rpm, it takes about 10 to 20*s to finely adjust the position of the magnetic head, but this time is no longer necessary.

(Effects of the Invention) As described above, according to the present invention, a magnetic head for tracing a data magnetic disk medium is provided with a head section dedicated to reading/writing data and a head section dedicated to reading servo signals. Accordingly, data can be read/written while performing positioning control to eliminate off-track of the data head.

Therefore, the on-track accuracy of the data head is increased and the read/write data quality of the data head is increased. Therefore, it is possible to increase the track density and increase the storage capacity of the magnetic disk device. Moreover, access time can also be shortened.

As a result, a compact, high-speed, high-storage capacity magnetic disk device can be realized.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the basic principle of the present invention, and FIG. 2 is a diagram explaining the basic principle of the present invention.
Figures illustrating the embodiment, (a) is a perspective view of a thin film magnetic head, (b) is a block diagram explaining the magnetic head positioning mechanism, and Figure 3 shows the magnetic head positioning procedure and data reading/writing. In the diagrams, (a) is a flowchart showing the procedure, (b) is a diagram showing the time allocation of each procedure, FIG. 4 is a block diagram explaining the outline of the magnetic head positioning mechanism, and FIG. FIG. 6 is a diagram explaining the magnetic head positioning procedure and data reading/writing, in which (a) is a flowchart showing the procedure, (b) is a diagram showing the time allocation of each procedure, and FIG. These are diagrams explaining the actual fine adjustment. (a) is a diagram explaining each area of a data magnetic disk medium, (b) is a diagram explaining servo signal tracks provided in the servo signal recording area, and (c) is a diagram explaining the servo signal track provided in the servo signal recording area. FIG. 3 is a diagram showing an output signal waveform when a data head traces a servo signal track. In the figure, Ia, lb, lc are magnetic disk media, 2 is a spindle, 3 is a spindle motor, 4a, 4
b. 4c, 4d, 4e, 4f, 4g are data heads, 5 is a servo head, 6 is a support spring, 7 is a drive arm, 8 is a carriage, 9 is an actuator, IO is a position detection circuit, 11. lla is the control circuit, 12.12a
is a fine position detection circuit, 13 is a switch circuit,
14 is a positioning address signal, 15a, 15b, 1
5c, 15d, 15e, 15f are servo signal recording areas, 16a, 16b, 16c, 16d, 16e
, 16f is the data signal recording area, 1? a,! 7b is a servo signal track, 18 is a data signal track, 19a,
19b is a head portion, 20 is a core slider, 21a, 2
1b indicates a thin film head portion.

Claims (1)

[Claims] 1. Perform seek control of the magnetic head based on the servo signal recorded on the servo surface, and then perform the servo signal track (17a) recorded at a specific position on the data surface data signal track (18). , 17b), in which a magnetic head (4d) for tracing a data surface is provided with two head portions (19a, 19b), and The interval (l_2) between the head parts (19a, 19b) is an integral multiple of the interval (l_1) between the data signal tracks (18),
Either one of the data surface magnetic heads (4d) is used exclusively for reading/writing data on the data signal track (18), and the other head is used for reading/writing data on the servo signal track (17a, 17b). A magnetic disk device characterized by: being used for exclusive use. 2. Perform seek control of the magnetic head based on the servo signal recorded on the servo surface, and then record the servo signal on the servo signal track (17a, 17b) at a specific position on the data surface data signal track (18). In a magnetic disk device that corrects and controls the position of a magnetic head based on ) is an integral multiple of the interval (14) between the data signal tracks (18), and one of the heads of the data surface magnetic head (4d) is connected to the data signal track (18). The magnetic head (4d) is used exclusively for reading/writing data, and the other head section is used only for reading the servo signal tracks (17a, 17b), and based on the servo signal obtained from the servo signal read-only head section, the magnetic head (4d) 1. A method for positioning a magnetic head, comprising: performing data read/write using the data read/write head section while correcting and controlling the position of the magnetic head.