JPS6185679A - Head position adjustment of disk device - Google Patents

Abstract

PURPOSE:To adjust the position drift of a head to a minimal one by adjusting the head position drift with respect to two adjusting tracks installed at an interval corresponding to the rotational frequency of a screw with the aid of a screw rotating angle. CONSTITUTION:A ball 12 of extension part 11 of a carriage 7 is engaged with a groove 10 of the screw 9 driven by a stepping motor 8, and the rotation of the screw 9 moves the head 5. On the other hand, an adjusting screw 21 is provided with the 1st and 2nd adjusting tracks 22 and 23 having intervals corresponding to the rotational frequency of the screw 9. With this constitution an adjusting disk 2 is mounted instead of the disk 1 to read burst signals A1 and B1 by the head 5. Then the screw 19 is loosened so that the burst signals A1 and B1 can be substantially equal to turn a fitting plate 18, and a screw rotating angle is adjusted. The track 23 is handled in the same manner. Thus the head position drift with respect to tracks except the adjusting one can be suppressed by minimal amount.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for adjusting the head position of a disk device for recording and/or reproducing data. [Prior Art] A mechanism in which a head is moved in the radial direction of a fat disc + Th moving device using a screw is well known. The mechanism of this cypress is Stempi: y f -T-
-I F School! J knee and M together JE! :, this screw 17) 14K is configured to move the head carriage in the radial direction of the disk, both of which are pressed by temporary springs. By the way, the step (m
Is the head positioned on a predetermined track when the stepping motor Ta:ljA is activated? Assure. For this reason, use an adjustment disc. It is checked whether the head is in the proper position with respect to the adjustment track on the disk, and the head is adjusted to the proper position. [The problem that the invention is trying to solve] By the way, if the head is in the proper position with respect to the adjustment recording track of the adjustment disk, the actual data recording and/or advantages and disadvantages corresponding to this adjustment recording track will be recorded. The head is also placed in the correct position relative to the tracks on the disk. Also,
The screw is for feeding! A difference: I/1. Because it is configured so that it will not be attacked. The head position of the screw after several rotations of the bale also corresponds to the 7N desired track. However, the eccentricity of the screw when forming with a rotation of 1 tnw on a lead screw machine tool,
Also, due to eccentricity of the screw when it is set, a periodic error occurs with a period of 1 rotation of the screw. FIG. 6 shows the relationship between the screw rotation angle θ and the head movement distance. If the screw is formed to f:, 6f1, the head movement distance will change linearly as shown by the one-dot line, but in reality it is 2π

[One rotation] The head movement distance is synchronized with the solid line. Therefore, a periodic position error as shown in FIG. 7 occurs between the head and the track on the disk. Conventionally, the head position was adjusted by taking into account periodic fluctuations as shown in Figure 6! ' 2 (・na-・・) There is a possibility that the head position adjustment is performed on the ?A alignment track that corresponds to the highest or lowest point of the fluctuation range, and in this case, the image width of the periodic fluctuation There is a possibility that the trunk position n, which is equivalent to twice (2b) as much as [Means for Solving the Problems] The head position adjustment method according to the present invention for solving the above-mentioned problem A uses a rotating device for a recording medium disk and #
The converter head includes a conversion head that changes the signal while facing the disk, a motor for changing the position of the head in the disk radial direction, and a screw that rotates in accordance with the rotation of the motor. Episode & Difference 1! A method for adjusting the head position of a disk device equipped with a head movement WtIJ mechanism that converts tIJ into a linear motion of the head to move the head in the radial direction of the disk, using a disk drive for head position adjustment.・The first adjustment track, where a is the pitch of the screw, Tp is the track pitch of the recording medium disk, and n is an integer other than zero. Prepare a head position adjustment disk R having at least an adjustment trunk, and rotate this head position adjustment disk χ with a sharpening rotation device.
By driving the motor Z, the head is moved to the first and second adjustment tracks, and the records of the first and second adjustment tracks are read by the head, and the read outputs are as follows. At least the angular position of the screw in the rotational direction is adjusted so that the positional deviation of the head with respect to the first and second adjustment tracks becomes substantially zero or near zero. It is something to do. [Function] The number of trunks between the 10g adjustment track and the second adjustment track at the above starting point aA is C) n. This corresponds to half a rotation of the lead screw, or n times this. If the rotation angle position of the screw is adjusted so that the error in the head position with respect to the first and second adjustment tracks set in this way becomes substantially zero, the position of the head on tracks other than the adjustment trunk can be adjusted to 8. The periodic error can be suppressed to less than the vehicle width. [Example] Next, referring to Figure 1, a magnetic disk device and a head position adjustment method according to an embodiment of the present invention will be explained. What is the magnetic disk device shown in Figure 1? Data is recorded or reproduced using a disk cartridge consisting of a flexible magnetic disk stack and its case (21), and the disk is equipped with a rotating device [141 and this disk 1) 1K slider. It is provided with a magnetic head +57 in contact with the head f57 and a moving mechanism +61 for moving the head f57 s'nm in the radial direction of the Y disk Il+. Head moving mechanism 167f"L. Carriage that supports the head (5) +71"Y stepping motor (81) configured to drive the rotational movement of the O stepping motor (8).
7) In order to convert the movement into a linear motion, a sliding mechanism is provided for the legs and the lead screw. That is, a screw (9) is connected to the shaft of the stepping motor (8), and a ball α4 supported by an extension Uυ of the carriage (7) engages with the groove of this screw (9). Paul [4 is pressed against #lQI with temporary spring u3J]
・Ru. The carriage (7) is guided in the disk radial direction by a guide rod (141) and is prevented from rotating. Therefore, the stepping motor (8) and the screw (9)
) is the rotor, the ball circle is pushed by the groove 4, and the ball circle and carriage 17) are displaced in the disk radial direction.
1, and is attached to an arm UE supported by a carriage. Since this embodiment is a single-sided disk device, there is one head (5), In the case of a mold, another magnetic head arrangement is used instead of the band A9.The stepping motor T8J has its rotational direction angular position adjusted to I14 as shown in Fig. 2.
It is fixed to the supporting board by screws A3 using a mounting having holes (1?) and holes (1?). It is necessary to respond to For this purpose, it is necessary to adjust the head position R in 41 steps of the stepping motor (8) so that the head (5) corresponds to a specific trunk of the disk mount. FIG. 4 shows an adjustment disk rotation for making such adjustments. This adjustment disk (X!) has one according to the present invention, therefore, first and second adjustment tracks QllΩ, that is, alignment tracks are provided on concentric circles, and the inner circumference and outer circumference are provided with the center of the track added as a reference. Burst signals AI, B, B, are recorded respectively. , burst signal Al m A, -Bj -B, is disk C
It is not recorded in one revolution of the ID, but is recorded only within a certain angular range. The centers of the first and second adjustment tracks (i?2Q3) are determined to correspond to each other. However, as is clear from diagram ig3, a is a screw pitch of <9J, and the i recording medium disk of Tpt engineering 1st - has a track pitch of 1, and in the actual tM example, it can be set to Tp = -. Corresponding to the number of trunks (9) means that it is set to Lll''- after all.In short, it works in conjunction with the feed amount that approximately corresponds to a half rotation of the L□F varnish screen (9).Fourth In order to adjust the position of the head (2) in FIG. 1 using the adjustment disk 3v shown in the figure, attach the adjustment disk QD to the disk device 1c shown in FIG. is applied to the stepping motor (8) at a rate of, for example, 2 steps per trunk or 1 track per step, and the head 157 is moved to the first adjustment track.Then, at this head position, the head 157 is moved to the first adjustment track tJ21σ. ] The burst signal Alb Bll is read and the reproduced output waveform shown in FIG. The head (5) is placed without any misalignment, and the stepping motor (8)
) and 0 to adjust the angular position of the screw t9J in the rotational direction. A step signal is required for adjusting the head T5J to the second adjustment track. Temping motor (
8), head + 5 no yrm2 adjustment track Q3
Now, read the burst signal of the second vibration damping trunk, read the output waveform of Figure 5 (81), and obtain the reproduction output waveform of the first adjustment track (
The rotation angle of the stepping motor (8) and the screw (9) should be adjusted so that the error in the position of the stepper motor (8) and the screw (9) is substantially zero. A Adjust. In addition, in reality, it is difficult to reduce the error to zero, so
Error X in the first vI4I4Sitrac 21, = 1
-bσ) 5A so that the absolute values are equal to each other near zero. If the head (5) is positioned with respect to the first and second 04 adjustment track horns having the spacing corresponding to the country of the screw (9), then the screw (9) will be adjusted. The position A of the head +5J is adjusted at the center of the periodic error accompanying the rotation, and the result is the modulus DK. When the recording medium disk stack is attached to the disk device for which the above-mentioned adjustment has been completed and recording or playback is performed,
The maximum value of the error between the head +5J and the track caused by the periodic error caused by the screw (9) is half the periodic difference variation width (peak peaks) caused by the screw (9). Therefore, during mass production of disk devices, it is possible to reduce the periodic error caused by the screw (9) to approximately 100% compared to the conventional method.First and second adjustment tracks @ I will explain in more detail why it is possible to run between Ω.Now, as shown in Fig. 3, the pitch of the screw (9) is a. When the rotation angle is #nθ, the following equation holds true, ignoring errors: L=all/2π ・・・・・・・・・・・・・・・・・・
...+1) However, in general, the processing accuracy of the screw is +9J. It has been found that there are 5 periodic fluctuations in the installation based on accuracy, etc., as shown by the following equation. L=aθ/2 yr + b stn (θ+(1)
・-T-1--+21 In the above +21 formula-・te-b
sin (θ+α) is stingy with periodic fluctuations (error), b
is the maximum value of the periodic f-shift radiation. α is the initial phase. The moving distance indicated by the dark line in Fig. 6 corresponds to Equation 21, and the one-dot line corresponds to a0/2π. This means that the track position! (positional deviation tii!4 difference between the track and the head (5) due to changes in the track value) will fluctuate by 7 degrees as shown in FIG. N!E so that the head is in the optimal position for the two adjustment tracks.If the position of the conventional adjustment track corresponds to the point T where the error drum shape in Figure 7 crosses its center line. When the head is completely positioned with respect to the trunk at this position, the maximum error occurring in other trunks is b, which is kept relatively low. In the method described above, the position of rank y1![) is determined to correspond to point T1, and the head is completely positioned with respect to the track σ), then 1) the track of the head of maximum 2b in the track j2 A deviation tKA difference) 7 occurs. On the other hand, in the present invention, the first adjustment track position T1
and the $2 adjustment track position tT, and the head position m.
In order to perform xuv, the maximum value of the head track deviation t1) difference in tracks other than the adjustment track can be set to b. Now, if the relationship between the error and the first and second adjusted track positions T+,'L according to the present invention before the head position adjustment is as shown by the dark line, then the track position tit T+. Different errors C+ * C * 7 for T and S-.
I have it. Therefore, turn the stepping motor (8) and screw (9Jχ) a little to shift the error waveform to the position shown by the dotted line. By shifting the first and second adjustment tracks and heads (
The positional deviation (error) with respect to 5) becomes substantially zero. a first adjusted trunk position T, and a second adjusted track position fl'
Since the interval rt h corresponds to the half circumference of the screw (9), that is, the phase angle π of the frame difference waveform, it is possible to substantially reduce the error of both the first and second a1 alignment tracks to zero. . If the adjustment is made in this manner, an error of 5 or more at maximum will not occur in any track other than the 1st kU 20th breast reduction track. In the embodiment, the mutual spacing between the first and second adjustment tracks corresponds to the rotational phase angle π9 of the screw (9), and the mutual spacing corresponds to 2π, 3π, etc. to adjust the head position spacing as (□)×Tp. It can be done. In addition, in order to obtain the effect of adjusting at the center of the difference (hysteresis error) between when the stepping motor (8i) moves in the step-out direction and when it moves in the step-in direction, the first adjustment trunk In order to move the head (5), the stepping motor (8) is driven in the step-out direction, and in order to move the head (8) to the second adjustment track, the stepping motor (8) is driven in the non-step-in direction. It is desirable that the present invention is not limited to the above-described embodiment, but can be further modified. For example, in addition to the Ml and the second adjustment trunk, it is possible to add , and further 4th.
A plurality of fifth adjustment trunks are provided, the intervals between these trunks correspond to a half circumference of the lead screw (9) or an integral multiple thereof, two or more of the plurality of adjustment tracks are used, and this Head against trunk such as (
You can adjust it so that position 9 in 5) is essentially zero. In addition, the signal that enters the adjustment trunk C2δ is
Instead of the burst signal K15 shown in FIG. 4, it can be replaced with a full signal that can detect trunk shift. Also, record the adjustment track. It is also possible to install it at multiple locations in one lap or around the entire circumference. [Effects of the Invention] As is clear from the above, according to the present invention, errors other than the adjustment trunk σ) head position relative to the track σ] can be easily reduced.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing a magnetic disk drive according to an embodiment of the present invention, FIG. 2 is a side view showing adjustment of the position of the stepping motor in the rotational direction;
FIG. 4 is a plan view showing the principle of the adjusting disc according to the present invention; FIG. 5 is an IAI (B)
1 is a waveform diagram showing the disk playback in Figure 4, Figure 6 is a diagram showing the relationship between the screw rotation angle and the head movement distance in Figure 1 f), and Figure 7 is a diagram showing the relationship between the track position and f). FIG. 4 is a box diagram showing the relationship with error. (1)...Disk, (4j...Rotating device, (5shi/spatula)-, 16J...#motive, (8)...Stepping motor, (9)...Screw, ( 2t...
Adjustment disk, (22J...first adjustment track,
@...2nd Mu) rack. Agent Nori Takano Figure 2

Claims (2)

[Claims] (1) A rotating device for a recording medium disk, a conversion head that faces the disk and converts signals, a motor for changing the position of the head in the disk radial direction, and a converter head that rotates following the rotation of the motor. A head position adjustment disk is used to adjust the head position of a disk device including a screw and a head movement mechanism that converts rotational movement of the motor into linear movement of the head to move the head in a radial direction of the disk. In the method of
adjustment track and from this first adjustment track (a/
(2T_p)) a second adjustment track provided at a position separated by n tracks (where a is the pitch of the screw, T_p is the track pitch of the recording medium disk, and n is an integer other than zero). preparing a head position adjustment disk, rotating the head position adjustment disk with the rotating device and driving the motor to move the head to the first and second adjustment tracks, respectively; The records of the first and second adjustment tracks are read by the head, and based on the read outputs, the positional deviation of the head with respect to the first and second adjustment tracks is substantially zero or near zero. A method for adjusting the head position of a disk device, characterized in that at least the angular position of the screw in the rotational direction is investigated. (2) Moving the head to the first adjustment track Vc is performed by rotating the motor in one direction, and moving the head to the second adjustment track is performed by rotating the motor. The head position adjustment method according to claim 1, wherein the head position adjustment method is performed by rotating the head in the other direction.