JPS63313373A - Magnetic head positioning system - Google Patents

Abstract

PURPOSE:To improve the reliability of recording/reproduction of data information by applying positioning tracing from the tracing quantity with respect to a track and the direction of track tracing by a magnetic head based on distortion information when the magnetic head cannot rad servo information of a specific sector. CONSTITUTION:The magnetic head 9 is positioned to a servo track-1 prior to the recording or reproduction of initial data information, the servo information is read to obtain information relating to the distortion of a medium. When the medium is deformed, since the direction and quantity of distortion at a position recorded with the servo information is obtained by reading out each servo information of the track, it is used as the distortion information. When the deformed quantity of the medium is small, positioning tracing is applied by using a position error signal from the readout servo information. On the other hand, when the deformation of the medium is large and no servo information can be read from a sector, it is corrected by using the distortion information from a servo track stored in advance. That is, the moving direction for position tracing of the magnetic head is determined by the information of distortion direction and the moving quantity is determined from the distortion quantity.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a storage device that records or reproduces information on a disc-shaped magnetic recording medium, in which a magnetic head is positioned on a predetermined track on the medium. The present invention relates to a magnetic head positioning method for positioning, and particularly to a magnetic head positioning method that uses a flexible medium and performs a positioning operation using a sector servo method.

[Conventional technology]

Among magnetic storage devices that use disk-shaped magnetic recording media, devices that use flexible recording media (floppy disks) employ means to increase rack density in order to increase their storage capacity. However, for this purpose, it is necessary to position the magnetic head on the desired track with high precision.

As a means to prevent this, each track on which data information is recorded (data track) is divided into multiple sectors (usually equally divided), and a specific positioning signal (servo information) is recorded in a part of each sector. When positioning the magnetic head, a so-called sector servo method is used in which this servo information is reproduced to generate a track position error signal, and the magnetic head is positioned based on this signal.

On the other hand, since floppy disks use a polymeric material for their disks, they expand and contract a large amount due to changes in temperature and humidity, and are also so-called anisotropic, with different expansion coefficients in the vertical and horizontal directions. are doing. For this reason, Figure 2 (a
), the circular track 11 in the standard state
a (shown by a solid line) is deformed by expansion or contraction to become a track 11b (shown by a dashed line) or a track 1l.
It becomes an elliptical state as shown in c (indicated by the broken line).
Therefore, as shown in FIG. 2(b), the track l
lb and llc have waveforms having two periods of high and low per rotation of the medium.

For example, one track is divided into eight sectors, 11-1 to 11-8, as shown in FIG. Considering a recorded medium, its track position varies in a waveform shown by reference numeral 11b or llc in FIG. 2(b).

On the other hand, in a magnetic head positioning method using servo control, when positioning the magnetic head by moving it from the currently positioned track to the next target track, servo control must first be used. A method is used in which the magnetic head is roughly moved to the vicinity of the target track, and then the magnetic head is precisely followed by the target track using servo control to perform a positioning operation.

In the positioning operation described above, when the moving operation (rough positioning operation) of the magnetic head without using servo control is completed, the position (trajectory) of the magnetic head on the medium is indicated by reference numeral 13 in FIG. It becomes a straight line as shown. On the other hand, the target track on the medium on which the magnetic head is positioned is deformed due to changes in temperature and humidity.
Assuming that the state is as shown in , there is no error in the position of the servo information ID2/ID4 to ID8 of even-numbered sectors and the magnetic head, but the servo information IDI of odd-numbered sectors is
・Since the temporary positioning of TD3 to TD7 is outside the range 12 in which the positional eddy difference of the magnetic head can be detected, it is impossible to detect the positional error. Therefore, the magnetic head follows the target track and does not transmit data information. It becomes impossible to play.

Reference numeral 11b in FIG. 3 indicates an example when the medium is in an expanded state.
By appropriately selecting the constituent materials and designing the structure, the 'tC configuration is such that changes in the position of the magnetic head due to changes in temperature and humidity compensate for changes in the position of the track due to expansion or contraction of the medium due to changes in temperature and humidity. has been done. Therefore, even when the medium is in a contracted state, the shape of the cona is exactly the same as in the above case.

In other words, even though the magnetic head is located at the average position of the target track of the medium, due to the anisotropy of the expansion coefficient of the medium, the magnetic head cannot follow the target track during servo control, and as a result, data Information may not be played back.

[Problem that the invention seeks to solve]

As mentioned above, a magnetic head divides one track into a plurality of sectors, records servo information in a portion of each sector, and corrects positioning errors using a track error signal obtained from the servo information. The sector servo type floppy disk 4uffl performs positioning by determining the tracking direction of the target track. It has the disadvantage that positioning may be impossible.

In a sector servo type floppy disk device, in order to increase its storage capacity, the number of sectors should be as small as possible, and the overall area for recording servo information should be smaller than the area for recording data information. However, in such a case, the interval between two pieces of adjacent servo information becomes wider, so that the above-mentioned drawbacks become more noticeable.

It is an object of the present invention to eliminate the drawbacks of the magnetic head positioning system of the conventional sector servo type floppy drive as described above, and to provide a good 4-way magnetic head positioning system that can follow a desired track even when the number of sectors is small. It is an object of the present invention to provide a magnetic head positioning system capable of obtaining a floppy disk drive r11 which has magnetic head characteristics, has a large storage capacity, and has excellent reliability in recording or reproducing data information.

[Means for solving problems]

The magnetic head positioning method of the present invention allows a specific servo track to be placed at any position on a floppy disk, and a position between the servo information recorded in each sector of a general data track on this servo track. One or more servo information is recorded in the servo track, and before recording or reproducing the data f# information of the 7-part disk device, the servo information of this servo track is read out and the track's rotation angle from the reference point is read out. The direction of distortion and the amount of distortion are stored as distortion information, and when positioning on an arbitrary data track, a position error signal obtained from servo information of each sector of the data track and the distortion information are used together, If the magnetic head cannot read the servo information of a specific sector, the distortion information (1) is used to determine the track following direction of the magnetic head and the amount of following operation for that track, and to perform positioning follow-up operation. configured.

〔Example〕

Next, let's discuss embodiments of the present invention with reference to page 1.

I will clarify.

FIG. 1 is an explanatory diagram showing the recording state of servo information on a servo track and a data track according to an embodiment of the present invention.

In this embodiment, a servo track (track number (1)) for specifically recording only the servo information for positioning the magnetic head is placed outside the outermost data track (track number (1)) of the floppy disk. (-1') ) is provided. (The servo track can be provided at any position, but it is best to set it at the outermost or innermost circumference.) All data tracks have servo information at the beginning of each divided sector. An area (reference numeral 21) is provided, and servo information is recorded in this area. The remaining portion is a data information area (reference numeral 22) for recording data information.

The servo information related to track (1) is the servo information 1aA (reference numeral 21a) recorded between the outer adjacent track (track number (ω)) and the inner adjacent track (track number (2)) and servo information B (reference numeral 21b) recorded across the servo information A and servo information B, which have different waveforms and cannot be distinguished. Therefore, when the magnetic head 9 is correctly positioned at the center of the track (1), the output from the servo information A and the output from the servo information B are equal in magnitude. When the positioning is off-centered to one side, the magnitude of the output due to these K increases unbalancedly. Therefore, correct positioning can be performed by following the position of the magnetic head 9 so that they are equal. .

In the servo track (track number (-1)), servo information A and servo information B are recorded at the same position as the servo information area of each sector of the data track.
Furthermore, servo information A with the same waveform is also placed in the intermediate position between them.
(reference number 21c) and servo information B (reference number 21
d) is recorded. (Intermediate servo information is not limited to one location, but may be in two or more locations or consecutively on the entire servo track.) Data information can be recorded or When performing playback, follow the steps below.

That is, before the first data information recording or reproducing operation, the magnetic head 9 is first positioned on the servo track (track number (-1)), and the servo information is read from there to obtain information regarding the distortion of the medium. . When the medium is deformed as shown in Figure 2, the distortion at the position (rotation angle from the reference point) where the servo information is recorded can be detected by reading out all of the servo information on the servo track described above. Since the direction (outer circumferential direction or inner circumferential direction) and the amount of distortion (ik, in which the magnetic head requires position adjustment) can be obtained, these are stored as distortion information.

When the above-mentioned preparatory operations are completed, normal data information recording and reproducing operations are performed. If the magnetic head is able to read all the servo information on the data track because the amount of deformation of the medium is small, the positioning follow-up operation is performed using the position error signal obtained from the read servo information, and in the data information area , the position tracked by the servo information of that sector is saved, and data information is recorded or reproduced.

If it is impossible to read servo information in a specific sector because the amount of deformation of the medium is large, write i:EI first.
Replenish this using the distortion information from the servo track you prepared. In other words, the direction of movement of the magnetic head for position tracking is determined from the information regarding the strain direction, and the amount of movement is determined from the information regarding the amount of distortion (obtained from the radius ratio of the servo track and the data track) to perform the positioning follow-up operation. I do.

Also, the length of one sector is long (the number of sectors is small)
Therefore, if the magnetic head is held at the position determined by the servo information of that sector, the position of the magnetic head will shift from the center of the data track in the latter half of the data information area, resulting in the output of recording or reproducing data information. If the servo information (reference numerals 21c and 21d) of the intermediate position decreases, the positioning follow-up operation of the magnetic head is performed using the strain direction and strain amount obtained from the previously stored intermediate position servo information (reference numerals 21c and 21d). As a result, data information can be recorded or reproduced while the magnetic head always follows the optimum position. In an extreme case, even if one track is made into one sector, it is possible to perform a recording or reproducing operation while making the magnetic head follow the deformed track by the above-mentioned means.

When recording or reproducing data continuously, the surrounding temperature and humidity environment will change, so the following operation will be performed based on the distortion information of the medium based on the servo information originally read from the servo track. In this case, it may become impossible to perform sufficient position adjustment of the magnetic head. To deal with such a case, it is possible to update the distortion information by reading the servo information from the servo track at appropriate time intervals, but it is also possible to update the distortion information by reading the servo information from the servo track at appropriate time intervals. Each time a positioning follow-up operation is performed on a data track of the playback station (or at an appropriate time interval) information regarding the distortion of the medium obtained from the data track (direction and magnitude of distortion, i.e. positioning follow-up operation) is obtained from the data track. The initial distortion information can be corrected according to the amount), and based on this correction result, subsequent positioning follow-up operations can be performed according to the procedure described above. by this,
Positioning follow-up operations can always be performed using the latest distortion information without performing any special operations to correct distortion information during continuous recording/reproducing operations.

〔Effect of the invention〕

As explained in detail above, the use of the magnetic head positioning method of the present invention has excellent tracking characteristics that can always follow the deformation even when the medium has anisotropic deformation in the sector servo method. This has the effect of making it possible to perform a positioning operation, and therefore has the effect of increasing the reliability of recording and reproducing data information in a floppy disk device.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the recording state of servo information on a servo track and a data track in an embodiment of the present invention, and FIGS. 2(a) and (b) are examples of anisotropic deformation states of a floppy disk. FIG. 3 is a schematic diagram and developed view showing the positional error detection range of the floppy disk having the modification shown in FIG. 9...magnetic head, lla, llb, 1lc-
...Truck, 11-1 to 11-8.20.30
・・・・・・Sector, 21a. 21c... Servo information A121b, 21d ・
... Servo information B0 1 Agent Patent attorney Susumu Uchihara ・, - Kaya 1
Kuni 114 Katamitsu, S Zhang Poison Seal Mi n1 Motoki So 7 (tL) Puten Hebi no etc. 2 Concave bud 3 M

Claims (1)

[Claims] A specific servo track is provided at an arbitrary position on a floppy disk, and one or more pieces of servo information are recorded at a position between the servo information recorded in each sector of the general data track on this servo track. Then, before recording or reproducing data information on the floppy disk device, the servo information of this servo track is read out and the direction and amount of distortion of the track with respect to the rotation angle from the reference point are stored as main information. When positioning on a given data track, the position error signal obtained from the servo information of each sector of that data track and the distortion information are used together, and if the magnetic head cannot read the servo information of a specific sector, The magnetic head positioning method is characterized in that the track following direction of the magnetic head and the amount of following operation with respect to the track are determined based on the distortion information, and the positioning follow-up operation is performed.