JPS62287414A - Tracking adjustment method for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve the precision of positioning of a magnetic head by using an alignment disk and a tracking adjustment device to measure the rest angle error, the hysteresis error, and the cumulative error of a track and holding down a maximum value and a minimum value of all error values to allowable values or smaller. CONSTITUTION:An alignment disk 5 is inserted to a magnetic recording and reproducing device 6 to seek a reference track, and a step motor 3 is set for inward seek, and a to be measured is seeked with a carriage 2 on which a magnetic head 1 is mounted, and data is taken in by the magnetic head 1. Tracks corresponding to respective excitation phases of the step motor 3 are seeked to repeat measurement. After inward seek, the step motor 3 is set for onward seek, and a track to be measured is seeked with the carriage 2, and data is taken in by the magnetic head 1. Tracks corresponding to respective excitation phases are seeked to repeat measurement. If the extent of off-track exceeds an allowable value, readjustment is performed and measurement is performed to hold down the extent of off-track to the allowable value or smaller by adjustment.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a tracking adjustment method suitable for positioning a magnetic head of a magnetic recording/reproducing device to a predetermined track on a magnetic recording medium.

[Conventional technology]

The conventional tracking adjustment method is the Japanese Patent Publication No. 59-7142.
The track diameter adjustment signal was reproduced by a magnetic head using an alignment disk on which marker markers and a track diameter adjustment signal were recorded as described in 1. The track diameter adjustment signal was displayed on an oscilloscope, and the adjustment was performed on only one track. However, high density (
96Tpi, 100Tpi, and 135Tpi), tracking adjustment including the static angle error, hysteresis error, and cumulative error of the step motor was not considered in data compatibility.

Furthermore, it has not been possible to determine the chucking error between the magnetic recording/reproducing device and the alignment disk from the form of the track diameter signal.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, in the first tracking adjustment to maintain data compatibility, the static angle error of the step motor,
No consideration is given to hysteresis errors and cumulative errors, and there is a problem in that large off-track errors occur in tracks other than the adjustment track or in the innermost and outermost tracks, resulting in write and read errors. Furthermore, no consideration is given to the chucking error between the magnetic recording/reproducing device and the magnetic recording medium, and there is a problem in that eccentricity causes a large off-track amount and errors.

An object of the present invention is to improve the positioning accuracy of a magnetic head due to static angle errors, hysteresis errors, and cumulative errors of a step motor.

Another object of the present invention is to determine chucking errors in magnetic recording media.

[Means for solving problems]

The above purpose is to measure the static angle error, hysteresis error, and cumulative error of the track corresponding to each excitation phase of the step motor using an alignment disk and a tracking adjustment device, display the total error value, and calculate the error value. This is achieved by ensuring that the maximum and minimum values of are below the allowable values.

In addition, for highly accurate adjustment, calculate the average value of all error values and align this average value with the reference track center of the alignment disc.

achieved.

Furthermore, this is achieved by measuring the chucking error of the magnetic recording/reproducing device using an alignment disk and a tracking adjustment device in which the track diameter adjustment signal is divided into 8 or 16 pairs.

[Effect]

The tracking adjustment method uses an alignment disk and a tracking adjustment device to measure static angle errors at tracks corresponding to each excitation phase of the step motor (for example, 29°, 36, 43, and 50 tracks).

The off-track amount at which the hysteresis error was measured is displayed on the display, and the step motor of the magnetic recording/reproducing device is finely adjusted in the track radial direction so that the off-track amount on all measured tracks is less than the allowable value.

Thereby, the position error of the magnetic head is minimized,
Since data compatibility can be maintained, write/read errors are eliminated.

In addition, when using an alignment disk and a tracking adjustment device in which the track diameter adjustment signal is divided into 8 pairs or 16 pairs, if the alignment disk center is chucked with a deviation from the rotation center of the magnetic recording/reproducing device, the track diameter xm signal The deviation is displayed as the off-track amount.

As a result, the chucking error can be measured, so that it can be distinguished from the positioning error of the magnetic head caused by the step motor, and the tracking adjustment time can be shortened.

[Embodiments of the invention]

The structure of the magnetic recording/reproducing apparatus and the tracking adjustment method will be explained below with reference to FIG. 1.A carriage 2 carrying a magnetic head 1 is moved in the track radial direction via a steel belt 4 by driving a step motor 3. Here, tracking adjustment is necessary for data compatibility, which is the lifeblood of the magnetic recording/reproducing device 5. First, apply the track diameter adjustment signal 17 (see alignment disk in Figure 5) on the reference track center 8! i! The recorded alignment disk 6 is inserted, and the track diameter adjustment signal 1 is read by the magnetic head 1.
7 is read out, and the step motor 3 is finely adjusted in the track radial direction P or Q direction to position the magnetic head 1 and maintain data compatibility of the magnetic recording/reproducing device 5.

Next, the off-track amount according to the tracking adjustment direction of this embodiment will be explained with reference to FIG. 2.3.4.

Magnetic recording and reproducing device! ! 5, tracks corresponding to each excitation phase of the step motor 3 (in this embodiment, tracks corresponding to the four-phase excitation step motor 3
) 29, 36, 43, and 50 tracks with track diameter adjustment signals 17 recorded thereon and a tracking adjustment device capable of measuring the off-track amount of the magnetic head 1 (see Fig. 6). The off-track amount is displayed on the display, the off-track amount 10 in the clockwise direction (from the inner circumference to the outer circumference) of the step motor 3 is displayed as a mark, and the off-track amount 9 in the counterclockwise direction (from the outer circumference to the inner circumference) is displayed. Displayed as 0 mark, maximum off-track amount 1o
ae Ik small value 9a is tolerance value 10b (±2 at 96Tpi)
Finely adjust the step motor 3 in the track radial direction so that the distance is less than ±15 μm at 35 Tpi.

Next, the off-track amount by the four-phase tracking adjustment method of this embodiment will be explained with reference to FIG.

In the tracking adjustment means of the magnetic head 1 of the magnetic recording and reproducing bag fli5, the track diameter is adjusted to tracks 29, 36, 43, and 50 corresponding to each excitation phase of the step motor 3 (in the case of a four-phase excitation step motor in this example). signal 17
1 using a tracking adjustment device that can measure the amount of off-track by reading the alignment disk 6 recorded with the track diameter adjustment signal 17 with the magnetic head 1.
．． The off-track amount of each measurement track is displayed, and the off-track amount 10 in the clockwise direction (from the inner circumference to the outer circumference) of the step motor 3 is displayed as a mark. 1 The off-track amount in the counterclockwise direction (from the outer circumference to the inner circumference) 9 is displayed as a 0 mark, and the average value 11 of the total off-track amount is calculated and displayed. If the off-track amount exceeds 20 μm, finely adjust the step motor in the track radial direction to set the average value 7 to the alignment disc. 6
According to this embodiment, the off-track amount of the magnetic head 1 on all tracks is 20 μm or less, and the positioning accuracy of the magnetic head 1 is improved. There is an effect.

The amount of off-track by the six-phase tracking vRm method of this embodiment will be explained with reference to FIG.

In the tracking adjustment means of the magnetic recording/reproducing bag +125, tracks corresponding to each excitation phase (in this embodiment, a four-phase excitation step motor) 29, 36, 43° 50, and tracks 02.74 near the outermost and outermost peripheries of the same excitation phase are The off-track amount of each measurement track is displayed using an alignment disk 6 on which the track diameter adjustment signal 17 is recorded and a tracking adjustment device 11 that can measure the off-track amount by reading the track diameter signal with the magnetic head 1. 3, the off-track amount 10 in the clockwise direction (from the inner circumference to the outer circumference) is displayed as a mark, and the off-track amount 9 in the counterclockwise direction (from the outer circumference to the inner circumference) is displayed as a 0 mark, and the total off-track amount Calculate and display the average value 7 of For example, there is an effect of improving the positioning accuracy and reliability of the magnetic head including the inner and outer circumferences. Also! 5! If the tolerance values cannot be distributed sufficiently, it can be determined whether the step motor 3 is defective or the assembly is defective, which has the effect of improving productivity during reassembly.

Next, a flowchart of the tracking adjustment method of this embodiment will be explained with reference to FIG.

Insert the alignment disk 5 into the magnetic recording/reproducing device 6, first seek to the reference track φφ, first set the step motor 3 to seek in the inner circumferential direction, then seek the carriage 2 carrying the magnetic head 1 to the measurement track, and then Data is taken in by the magnetic head 1 on a track corresponding to each excitation phase of the step motor 3 (29.36 in the case of 4 phases).
, 43゜50) Seek to the track and repeat the measurement. When the seek in the inner circumferential direction is completed, set the step motor 3 to seek in the outer circumferential direction, then seek the carriage 2 to the measurement track, and then take in data with the magnetic head 1. , this is sought to the track (29°36.43,50) corresponding to each excitation phase and the measurement is repeated.

Next, display the off-track amounts 9 and 10 on the measurement track on the disc display, and check that the off-track is the allowable value (5 inches 9
If it exceeds (approximately ±20 μm for 6TPi), readjust and measure again, and adjust so that the off-track amount is below the allowable value.

Further, a tracking adjustment method based on chucking accuracy according to this embodiment will be explained with reference to FIG.

Using an alignment disk that divides the track diameter adjustment signal into 8 pairs or 16 pairs and a tracking adjustment device, measure and display the counterclockwise off-track amount 102 and the clockwise off-track amount 9 for each measurement track, and measure and display the counterclockwise off-track amount 9 for each measurement track. Half of the off-track amount 9, 10 at is the chucking error S.

Further, the difference between the off-track amount in the counterclockwise direction and the clockwise direction becomes the hysteresis error H of the step motor, and the maximum value of the off-track amount is 10a and the minimum value is 9a.

According to one example of fine-tuning the step motor 3 so that it is below the tolerance value 10b, the amount of off-track is large due to the static angle error and hysteresis error of the step motor 3, or the amount of off-track is large due to the chucking error S. This has the effect of improving productivity because it can be determined whether the

Next, the tracking adjustment device of the present invention will be explained with reference to FIG. First, the alignment disk 6 on which a track diameter adjustment signal is recorded on a predetermined track is inserted into the magnetic recording/reproducing device 5. After the magnetic head 1 is moved by the personal computer 11 via the magnetic disk control circuit 12 to the outermost circumferential track serving as a reference, the magnetic head 1 is moved to a specified track recorded on the alignment disk 6. On this track, play the track adjustment signal and! The first current circuit 13 converts the voltage into a DC voltage containing ripple components, and the filter 14 removes high frequency ripple components. The output of this filter 14 is digitized by the A/D converter 15, and the data is taken into the memory of the personal computer 11 via l1016.Then, the off-track amount is determined by the data in the memory.
The same process is performed by moving the magnetic head 1 further toward the inner circumference of the zero-order alignment disk 6 to be calculated.

Similarly, after data is captured on the remaining tracks, the direction of movement is changed again and the magnetic head is moved from the inner circumference to the outer circumference and the same process is performed.When the data capture and processing on a predetermined track is completed, On the screen of the personal computer 11, vertical deviation of the magnetic head 1, static angle error of the step motor, hysteresis error due to the rotation direction of the STM, cumulative error due to the transmission system, etc. are displayed.

An example of the alignment disk 6 used in this case is shown in FIG.
．． Eight pairs of inner signals 6a and outer signals 6b extending geometrically alternately from 21 to the inner and outer sides are provided symmetrically with respect to the center axis 22 of one rotation.

Further, on the alignment disk 6, track diameter adjustment signals 17 are arranged at reference track centers 18.19° and 20.21° corresponding to each phase with the same number of phases as the step motor (four phases in this embodiment). There is. Further, the same signal as above is also written on the back surface of the alignment disk 6.

〔Effect of the invention〕

According to the present invention, since the magnetic head positioning accuracy on all tracks can be minimized, there is an effect of improving reliability. In addition, it is possible to determine whether the parts of the step motor are acceptable by measuring the static angle error and hysteresis error of the step motor, and whether the assembly is acceptable or not can be determined by measuring the cumulative error and chucking error of the step motor, thereby improving productivity.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a top view of a magnetic recording and reproducing device, FIGS. 2 to 4 are characteristic diagrams of off-track amount, and FIG. 5 is a flow chart of a tracking adjustment method. FIG. 6 is a diagram showing a tracking adjustment method using a chucking error, FIG. 7 is a diagram showing the principle of the tracking adjustment device, and FIG. 8 is a diagram showing the principle structure of the alignment disk.

Claims (1)

[Claims] 1. A magnetic recording and reproducing device comprising a carriage mounting at least one magnetic head capable of magnetic recording and reproducing, and a step motor that moves the carriage in a track radial direction on a magnetic recording medium. , in the tracking adjustment method for positioning the magnetic head on a predetermined track, an alignment disk having track diameter adjustment signals recorded on tracks that are equal to or more than the number of excitation phases of the step motor and that correspond to at least each excitation phase; Using a tracking adjustment device, the positioning error of the magnetic head including the static angle error of the step motor, that is, the amount of off-track, is measured by reading the track diameter signal with the magnetic head, and the maximum and minimum values of the off-track amount are measured. A tracking adjustment method for a magnetic recording/reproducing device, characterized in that the tracking adjustment value is adjusted to be less than or equal to a permissible amount. 2. In the tracking adjustment method according to claim 1, using an alignment disk and a tracking adjustment device, the magnetic head is moved in a track that is equal to or more than the number of excitation phases of the step motor and corresponds to at least each excitation phase. A tracking adjustment method for a magnetic recording/reproducing device, comprising measuring a positioning error, that is, an amount of off-track, and adjusting the average value of the amount of off-track over all measured tracks to a reference track center of an alignment disk. 3. In the tracking adjustment method according to claim 1, using the alignment disk and the tracking adjustment device, the carriage is moved to a track that is equal to or more than the number of excitation phases of the step motor and corresponds to at least each excitation phase. Move from the outer circumference to the inner circumference and from the inner circumference to the outer circumference,
A tracking adjustment method for a magnetic recording/reproducing device, comprising measuring a positioning error of a magnetic head, including a static angle error and a hysteresis error of a step motor, that is, an off-track amount. 4. In the tracking adjustment method according to claim 3, in addition to the number of excitation phases of the step motor and at least one track corresponding to each excitation phase, at least a track near the outermost circumference or near the innermost circumference Using an alignment disk with a track diameter adjustment signal recorded on the track and a tracking adjustment device, the static angle error of the step motor,
A tracking adjustment method for a magnetic recording/reproducing device, comprising measuring a positioning error of a magnetic head, including a hysteresis error and an accumulated error between an outer circumference and an inner circumference, that is, an off-track amount. 5. In the tracking adjustment method according to claim 3, the alignment disk is connected to a magnetic recording and reproducing device using an alignment disk in which a track diameter tone signal divided into 8 pairs or 16 pairs is recorded on one track and a tracking adjustment device. A tracking adjustment method for a magnetic recording/reproducing device, characterized in that a positioning error of a magnetic head including a chucking error occurring during chucking, a static angle error of a step motor, and a hysteresis error, that is, an off-track amount is measured.