JPS63104276A - Magnetic recording device - Google Patents

Abstract

PURPOSE:To reduce a correction frequency based on a bit of positional information by writing said required positional information upon format after a magnetic recording device is incorporated in system. CONSTITUTION:A CPU 11 is allowed a servo head 4 via a servo circuit 8 to position to a servo track in such an outer circle by two tracks further to a servo track corresponding to the outermost side data track in response to a format command from a host system. Under such conditions, a data head 5 writes along a locus of its center line with a pattern 13 those offset similar patterns 14 and 15 in succession at inner and outer circular sides of the center line as the positional information of recording data through a recording and reproducing control circuit 9, etc. The displacement amount of heads 4 and 5 are controlled based on a reproduced amplitude ratio of said patterns 14 and 15. This displacement amount variable according to the temperature, etc., is written on a RAM to be used for correction of the displacement. Incidentally, with no influences of variations during transferring, etc., the correction frequency based on the positional information of recording data is decreased and hence a decline of the throughput is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a head positioning method for a magnetic recording device.

[Conventional technology]

A magnetic recording device consists of a magnetic disk (hereinafter abbreviated as disk) and a magnetic head (hereinafter referred to as disk) that records and reproduces information on the disk.
(hereinafter abbreviated as head).

The head is fixed in five grooves for movement and positioning of the head. A large number of concentric data recording areas called tracks are provided on the disk, and by moving the head onto the tracks, information is recorded and reproduced between the disk and the head.

In conventional magnetic recording devices, one of the recording surfaces of the disk is dedicated to recording position information (hereinafter referred to as servo surface), and the remaining surface is used as a surface for recording data (
(hereinafter referred to as the data surface).

When a head placed in correspondence with the servo surface (hereinafter referred to as servo head) is positioned on a track that records positional information with the servo surface (hereinafter referred to as servo track), the head placed in correspondence with the data surface The track on which data is recorded (hereinafter referred to as data track) is the circular orbit on the data surface where the servo head (hereinafter referred to as data head) is positioned. The positioning mechanism is controlled so that the deviation from the target position is minimized, and the servo head is positioned on the target servo track, thereby secondarily positioning the data head on the target data track.

Although this positioning method allows the servo head to be accurately positioned on the servo track, thermal expansion and attachment of the disk and head, as well as the support mechanisms for the disk and head, occur due to changes in accuracy. It is not possible to correct the positioning error between the target data track and the data head.

Therefore, as shown in Japanese Patent Laid-Open No. 51-81603, second position information is recorded on the data surface, and by referring to this second position information, the first position information on the servo surface is corrected. , a method for accurately positioning the data head relative to the data track was devised.

[While the invention is trying to solve the problem]

The method of correcting the first position information recorded on the servo surface based on the second position information on the data surface allows the data head to be correctly positioned on the target data track. However, the number of shifts to be corrected is generally different for each data head, and the value to be corrected changes when the data head is switched. It is necessary to move it according to the direction to be corrected. The amount of movement of this mechanism is several microns or less at most, but since it is a mechanical operation, it takes several milliseconds.

Therefore, although it is possible to accurately position the data head using the second position information, the above-mentioned correction procedure takes time, and if correction is performed frequently,
m The throughput of the magnetic recording device decreases.

After the magnetic recording device is shipped from the factory, the mechanical parts of the magnetic recording device may become misaligned due to shocks during transportation.

As a result, for example, the data head may become misaligned relative to the servo head. If such a magnetic recording device is incorporated into a system as is and used, the data head can be accurately positioned using the second position information, but when selecting the aforementioned misaligned data head, it is necessary to correct the amount of misalignment. must be performed constantly, which leads to deterioration of the response time of the magnetic recording device.

An object of the present invention is to provide a magnetic recording device that improves the above-mentioned drawbacks.

[Means for solving problems]

The present invention provides a servo surface on which first position information used as a control signal for positioning a data head on a target data track is recorded, a data surface on which data and second position information are recorded, and a data surface on which data and second position information are recorded. a servo head arranged in correspondence with the servo surface, a data head arranged in correspondence with the data surface, and a control section that controls positioning of the data head on a target data track based on the first and second position information. In the magnetic recording device, the second position information is written by the magnetic recording device itself when the magnetic recording device is formatted.

[Effect]

According to the present invention, since the second position information is written on the data surface when the magnetic recording device is formatted after being incorporated into the system, the frequency of correction based on the second position information is reduced. The throughput of the recording device is improved.

[Implementation row]

The present invention will be described in detail below based on examples.

FIG. 1 is a schematic diagram of a mechanical section of an embodiment of the present invention.

A disk having a servo surface 1 and a data surface 2 is fixed to a main shaft motor 3 and rotates. Both the servo head 4 and the data head 5 are fixed in the positioning pk groove 6 and can be moved in the radial direction of the disk by a linear motor 7.

FIG. 2 is a block diagram showing the configuration of the circuit Fs in this embodiment. Each servo turn V8 is the one in which the servo head 4 moves to the target servo track based on the position information @l read from the servo head 4. This is a circuit for controlling the linear motor 7 so that the linear motor 7 is positioned at a certain position, and is used in conventional magnetic recording devices. However, the servo circuit of this implementation row is c
In response to the digital signal output from pσ11, the servo head can be offset from the target servo track by an amount corresponding to the digital signal. Since the servo circuit has conventionally had the function of making the servo head follow the target position, in order to add the above-mentioned function, it is only necessary to add an adder circuit using an iDA converter and an operational amplifier to reset the target position.

The recording and reproducing control circuit 9 converts the output of the data head 5 into digital data and transmits it to the interface circuit 10.
It is also a circuit that sends data transmitted from the host system via the interface circuit IO to the data head. The recording and reproducing control circuit further has a function of recording second position information, which will be described later, in front of the data, and reproducing it to detect the deviation between the data head and the data track.

In addition to transferring data with the host system, the interface circuit also controls formatting.Formatting involves dividing all data tracks into sectors before using a magnetic recording device as a storage device, and assigning track numbers, head numbers, It is necessary to write more information, including information such as sector numbers.

When a command to format is received from the host system, formatting is performed by the 7-bit control circuit in the interface circuit under the control of CPσ11.At this time, in the magnetic recording apparatus of the present invention, the 2 positions and information are written at the same time.

When the magnetic recording apparatus of this embodiment receives a format command, before formatting, it positions the servo head on a servo track two tracks further outward from the servo trunk corresponding to the outermost data track. At this time, the trajectory drawn by the center of the data head on the data surface is the third
13, which is the one-dot chain line in FIG. 12;
14, 15 magnetization reversals are sequentially written, 13, 1
The recording frequency of magnetization reversal in 4 and 15 is single, and is produced by frequency-dividing the output of a crystal oscillator in the magnetic recording device. First, position the data head on the dashed-dotted line 12b and pattern 13? In the magnetic recording device of one row, the width of the data head is 15 microns, and the width L6 of the shiba turn is about 15 microns.Firstly, the offset function in the servo circuit 8 described above allows the positioning mechanism section 6 to be adjusted by 5 microns. Write pattern 14'f: 0 with an offset toward the inner circumference of the disk.Next, write the entire pattern 15 with an offset of 5 microns toward the outer circumference.

This write operation is performed using the data head in the pan. The bears of patterns 14 and 15 are the 5th second pattern according to the present invention.
This is the location information.

When recording and reproducing data, the data head is positioned based on the track on which the second position information is written.In other words, when the environmental temperature changes, the servo is moved to the track on which the second position information is written. Data head by position information from the surface? Even after positioning, the center of the data head deviates from the center line 12. At this time, the amplitudes of the readout waveforms of patterns 14 and 15 read from the data head are not equal.1 The direction of the deviation of the data head can be determined by determining the size of both patterns. The amount of deviation can be determined by the ratio of the two. This determination is performed by a peak hold circuit, an AD converter, and CI'υ. In this way, the current amount of deviation between the servo head and the data head is detected. An offset function within circuit 8 can be used to correct for this deviation, thereby accurately positioning the data head on the data track.

The above-mentioned procedure of detecting and storing how much the data head deviates from its original position when the servo head is positioned on the servo track is carried out at appropriate time intervals. Every 5 minutes immediately after startup, and every hour after 2 hours after startup.
In between, there is an interval of 1() minute and an additional interval. Since the deviation of the data head from its original position is mainly caused by changes in the environmental temperature, the second position information may be referred to and the RAM updated at time intervals in which temperature changes become a problem.

When the servo head is positioned on the servo track, if the deviation from the original position of the data head is the same for all data tracks, it is only necessary to have one track on which the second position information is written per data surface. , If this is not the case, it is necessary to add a track with the second position information written in the one-track execution column, and only one track with the second position information written on the editor surface is required, as shown in Figure 3. It takes only 2 seconds to write a pattern on each of the five data planes, which is negligible compared to the time required for formatting.

〔Effect of the invention〕

As described above, according to the present invention, the second position information for accurately positioning the data head on the target data track is written after being incorporated into the system. The resulting deviation does not pose a problem, and the frequency of correcting the positioning mechanism section using the second position information is reduced, making it possible to improve the response speed of the magnetic recording device.

In addition, when the user re-formats the magnetic recording device after using it for a long period of time, the second position information is also rewritten, which simultaneously eliminates the effects of steady deviation due to misalignment of the mechanical part that has occurred over a long period of time. can.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the mechanical part of the implementation row of the present invention, FIG. 2 is a block diagram showing the circuit structure of the implementation row of the invention, and FIG. 3 is a diagram showing the second position information in the implementation row of the invention. A diagram showing a magnetization pattern. Applicant: Seiko Epson Co., Ltd. agent, patent attorney, senior affairs officer, and one other person. '1711 Figure 21J

Claims (1)

[Claims] A servo surface on which first position information used as a control signal for positioning the data head on the target data track is recorded, a data surface on which data and second position information are recorded, and a servo surface corresponding to the servo surface. a magnetic head, comprising: a servo head disposed in association with the data surface; a data head disposed in correspondence with the data surface; and a control section for controlling the positioning of the data head on a target data track based on the first and second position information. A magnetic recording device, wherein the second position information is written by the magnetic recording device itself when the magnetic recording device is formatted.