JPS62234221A - Tracking adjustment device for magnetic disk driving device - Google Patents

Abstract

PURPOSE:To adjust a magnetic disk driving device with a high precision by calculating and displaying a vertical error of a head, a stationary angle error of the driving device, a hysteresis error due to the feeding direction of a carriage, an accumulated error in a transmission system from the inside periphery to the outside periphery, etc. CONSTITUTION:A disk 24 is directly chucked on a rotating bearing part 34 of a driving motor 33 by a collet 32 and is rotated at a certain speed by the motor 33. A carriage 28 on which a magnetic head 19 is mounted can be moved in the radial direction of tracks by a stepping motor STM 25 and is positioned to a target track to record and reproduce data on the disk 24. The vertical assembling error of the magnetic head 29, the stationary angle error of the STM 25, the hysteresis error due to the feeding direction, the accumulated error of the transmission system accumulated in each step from the inside periphery to the outside periphery, etc., are filtered and are subjected to A/D conversion and are stored, and they are displayed on a personal computer.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a tracking adjustment device used for adjusting a helad carriage drive section of a magnetic disk drive to a specified track radial position, and particularly relates to a ,1゜0O
The present invention relates to a tracking adjustment device for a magnetic disk drive device capable of highly accurate adjustment work suitable for a magnetic disk drive device with a higher density than TPi (number of tracks per inch).

[Conventional technology]

A conventional tracking adjustment device for a magnetic disk drive device uses a marker mark and track position adjustment as described in Japanese Patent Publication No. 59-7142. ! Adjustment/adjustment signals from an alignment disk on which the signals were recorded were reproduced by a magnetic head of a magnetic disk drive and displayed on an oscilloscope, making it possible to adjust the position in the track radial direction.

However, the resolution of adjustment using an oscilloscope is low, and
Although it was possible to guarantee data compatibility with STPi class magnetic disk drives, 96TPi has a higher density.

This was difficult for magnetic disk drives of 100 T Pi class or higher. Further, other g*a factors, index timing adjustment and azimuth adjustment necessary for data compatibility were not considered.

Another conventional example will be explained with reference to FIG. 9. The alignment disk 1 is provided with an index timing adjustment signal 22 in the outer track, and a track diameter adjustment signal 22 in the center.
! As the signal 36, the specified dimension is approximately "C = 0.1.ms eccentric from the center axis 39 for one rotation, and approximately δ/2 = from the reference diameter.
A large-diameter signal 37 that is larger by 0.075+wm and a small-diameter signal 38 that is smaller by the same dimension are provided, and a method of detection using a signal called a so-called cat's eye is used. In addition, the azimuth adjustment signal 19 is applied to the inner track, and the CW (clockwise) signal 20. CCV (This is provided by the counterclockwise rotation signal 2J. The same signal is also written on the back side of the alignment disk 1, so that it is possible to adjust the two heads (upper and lower). As shown in FIG. 10, this alignment disk 1 is inserted into a magnetic disk drive device 2, the head carriage is moved to a specific track, each adjustment signal is reproduced, and this signal is displayed on an oscilloscope 40.

In the case of index timing adjustment, the time from the fall of the index signal to the index timing adjustment signal 22 is adjusted by adjusting the position of the index detection sensor.

To adjust the track diameter, fine-tune the stepping motor so that the ratio of the large diameter signal 37 and the small diameter signal 38 is the same, and to adjust the azimuth, adjust the head inclination so that there are 4 signal ratios @ within the head. .

According to this method, it is possible to verify the index timing and azimuth of the magnetic disk drive device, but the resolution is low when adjusting the track diameter using the tight eye signal, and the density is increased to 9 6 T P i .

It has been difficult to guarantee data compatibility for high-density magnetic disk drives of L 00 T Pi class or higher.

Furthermore, it was not possible to determine the chucking error from the form of the signal.

Here, the data compatibility of the high-density magnetic disk drive will be explained. Since multiple magnetic disk drives mutually record and reproduce data via removable magnetic disks, the difference between the specified track radial position and the position where the magnetic helad is positioned in the actual magnetic disk drive. (
Hereinafter abbreviated as off-track. ), and its main causes are (1) carriage position adjustment error, (2) carriage positioning error, and (3) chucking error that occurs when chucking the magnetic disk to the magnetic disk drive device.

(4) Differences in expansion and contraction of magnetic disks and magnetic disk drives due to temperature and humidity can be mentioned. Also, errors occur in index timing and azimuth between the two magnetic disk drive devices.

Here, in the magnetic disk drive device for 967P'i, the above-mentioned off-track tolerance value X is the R/W gap width of the magnetic head W = 165 μm, the erase core width F: r = 100 μm
It is known that it is related to m and is 50 μm. Therefore, for this x = 50 μm, the above (1) to (4)
) It is necessary to allocate error items to ensure data compatibility, but the difference in expansion and contraction due to temperature and humidity (4) is largely influenced by the physical properties of the material and is difficult to reduce.

Therefore, if we analyze (1) to (3), (1) the carriage position adjustment error is closely related to the adjustment time;
In order to suppress the error, the adjustment time will be significantly increased.

(2) Carriage positioning errors are thought to be caused by errors in the static angle of the stepping motor (hereinafter abbreviated as STM) itself, which is the drive source, errors in the transmission system, etc., but in high-density magnetic disk drives, Both the STM and the transmission system have reached the limits of manufacturing accuracy, and any attempt to further improve accuracy will result in a 1-point deterioration in yield, leading to increased costs and 9 quality instability.

(3) The main cause of chucking error is the accuracy of the chucking parts of the magnetic disk and magnetic disk drive.
Similar to (2) above, the required accuracy improvement in high-density magnetic disk drive devices has reached its limit.

[Problem that the invention seeks to solve]

As mentioned above, when increasing the density of magnetic disk drives, the precision required for each component has reached its limit, and in order to guarantee data compatibility between multiple magnetic disk drives,
It was necessary to either improve the precision required for each component, which would lead to an increase in cost, or to improve the precision of carriage position adjustment, which would increase assembly and adjustment time, which was more problematic than improving productivity and, ultimately, reliability.

The purpose of the invention is to use alignment disks to improve the accuracy of each component that occurs in a probability distribution with respect to each other.

Verify when assembling each magnetic disk drive, and improve carriage positioning accuracy and adjustment time.

An object of the present invention is to provide a tracking adjustment device that can shorten the time and improve productivity and reliability.

[Means for solving problems]

The above purpose is to generate a track diameter adjustment signal that is the same as the number of excitation phases of the STM that is the drive source of the carriage and corresponds to each phase, and a track diameter that corresponds to the track diameter near the outermost circumference and the innermost circumference in the track radial direction. Each track diameter adjustment signal has an inner circumferential side signal and an outer circumferential side signal that extend geometrically alternately to the inner circumferential side and the outer circumferential side from the specified track center as a pair. The carriage of the magnetic disk drive device into which the alignment disk, which is arranged symmetrically with respect to the center axis, is inserted is automatically moved from the outer circumference to the inner circumference, and the adjustment signal is recorded on the track where the adjustment signal is recorded. This is achieved by reproducing the information, A/I) converting it, storing it in a digital memory, and then calculating and displaying the contents of the memory after the carriage has finished moving.

In addition, by simultaneously verifying the index timing adjustment signal and azimuth adjustment signal, it is possible to understand the numerical values relative to the allowable values in three directions: the track radial direction of the magnetic head, index timing, and R/W gap inclination, improving reliability. We aim to

[Effect]

First, let's talk about the individual track diameter adjustment signals.Inner and outer signals, which geometrically extend from the center of the track to the inner and outer sides in alternating directions, are generated using the R/W gap of the magnetic head. By reading it out as a signal output, it is possible to numerically grasp how far the magnetic head is off-track toward the inner circumference or the outer circumference with respect to a specified track radial position.

In addition, since the pair of inner and outer signals are arranged symmetrically with respect to the rotation center axis, it is also possible to measure the chucking error, which is the eccentric component error that occurs when chucking the magnetic disk. .

Next, the track diameter R1 corresponding to each phase is the same as the number of STM phases! Since the static angle error of the STM and the moving direction of the carriage are changed from the inner circumference to the outer circumference and from the outer circumference to the inner circumference according to the signal, the hysteresis component can also be measured.

Furthermore, it is possible to determine the positioning error accumulated in the static angle error of the STM due to error factors in the transmission system, using the track radial direction signals corresponding to the track deviation near the outermost circumference and the innermost circumference in the track radial direction. .

Therefore, by verifying the accuracy distribution of each component of the magnetic disk drive after assembling the magnetic disk drive, it is possible to determine the tolerance for positioning of the head carriage drive, that is, for each magnetic disk drive. known about the device and with necessary and sufficient accuracy; iav! This eliminates the need for unnecessary adjustment time.
Productivity improvement.

It has the effect of increasing reliability. Further, if a sufficient adjustment tolerance cannot be obtained, it becomes clear which component is defective or the assembly is defective.

In addition to the above adjustment and verification in the track radial direction, by performing A/r) conversion at the same time from the index fall, and then referring to the address of the digital memory,
Verification of the rotational direction of the magnetic head Since the inclination direction of the magnetic head can be adjusted and verified numerically, highly accurate adjustment and verification can be achieved and reliability can be improved in response to higher density.

〔Example〕

Hereinafter, one embodiment of the present invention will be explained with reference to FIG. First, the alignment disk 1, on which track force direction, azimuth, and index timing adjustment signals are recorded on predetermined tracks, is inserted into the magnetic disk drive device 2. After the magnetic head is moved by the personal computer 7 via the magnetic disk control circuit 8 to the outermost track that serves as a reference.

A magnetic head is moved to a specified track recorded on an alignment disk 1. In this track, the adjustment signal is regenerated, converted into a DC voltage containing ripple components by a rectifier circuit 3, and high-frequency ripple components are removed by a filter 4. The output of this filter 4 is digitized by the AID converter 5, and the data is taken into the memory of the personal computer 7 via l106.Then, the values of off-track amount, index timing, azimuth, etc. are calculated using the data in the memory. Zero-order alignment disk 1. The magnetic head is moved further to the inner circumference and the same process is performed. After similarly capturing data on the remaining tracks, the direction of movement is changed again, the magnetic head is moved from the inner circumference to the outer circumference, and the same processing is performed. When the data acquisition and processing on a predetermined track are completed, the vertical misalignment of the magnetic head, ST
The static angle error of H, the hysteresis error due to the rotation direction of STM, the cumulative error due to the transmission system, etc. are displayed.

An example of the alignment disk used in this case is shown in FIG. Alignment disc 1 XI! Above the track center center 4, as a track diameter adjustment signal 16, an inner circumferential side signal 17 and an outer circumferential side signal 18 extending geometrically alternately from the M11 track center 14 to the inner circumferential side and the outer circumferential side are set as a pair.
The pairs are symmetrically provided with respect to the rotation center axis 9. Also, as the index timing adjustment signal 22, an index timing detection point (TI3
X) The current time T*edi is from 23. Furthermore, an azimuth adjustment signal] 9 is written by a signal writing head (not shown) adjusted to have prescribed alternations α and α' in the clockwise direction with respect to the radius line a extending from the rotation center 9 on the adjustment track center 14. CW signal 20 and CCW signal 21
The track diameter adjustment signals 16 are arranged alternately in one block pair.

In addition, the alignment disk 1 has an adjustment track center 1.
In addition to 4, track diameter adjustment signals 16 (index timing adjustment signals 22 and azimuth ) are arranged, and the track diameter adjustment signals 16 corresponding to the track diameters near the outermost circumference and near the innermost circumference in the track radial direction are arranged.
is placed at the center 10.15 of the adjustment track.

Furthermore, the same signals as above are written on the back surface of the alignment disk 1.

Next, the structure and operation of the magnetic disk drive device that is adjusted and verified using the alignment disk 1 will be explained with reference to FIG. The magnetic disk 24 is connected to a direct drive motor (hereinafter abbreviated as ID motor) 33 by a collet 32.
It is chucked to the rotation bearing part 34 of the DD motor, and is rotated at a constant speed by the DD motor. A carriage 28 carrying a magnetic head 29 is movable in the track radial direction by an 87M25, and is positioned at a target track to record and reproduce data on the magnetic disk 24. Here, to explain the head positioning mechanism, first, the rotation angle of the 87M25 fixed to a chassis (not shown) changes in a stepwise manner according to a control signal.

Therefore, the carriage 28 is linearly moved along the rail 35 via the steel belt wound α around the pulley 27. Therefore, the magnetic head 2 mounted on the carriage 28
9 also performs linear motion at regular intervals on the 1 m air disk 24 according to the rotation of the STM 2F). By setting this interval to the interval between tracks, the magnetic head 29 is positioned at the position of the track. Further, the index direction, which is the direction of rotation of the magnetic disk 24, is performed by an index timing light emitting section 30 and an index timing light receiving section 31.

Positioning error factors caused by such a magnetic head positioning mechanism include (1) static angle error of 87M25 and hysteresis error that changes with load, (2) roundness of pulley 27, thickness of steel belt 26, and winding method. (3) a chucking error, which is an error of an eccentric component that occurs when chucking the magnetic disk 24, and the like.

Here, as shown in Figure 4, the static angle error of 87M25 appears as an error curve with one period having the same number of steps as the number of phases of 87M25 (4 phases in this example), and the error between the same phases is small. is generally known. In the figure, each phase is denoted by o, ×, and Δ.

Indicated by mouth symbol. Therefore, in order to find the rest angle of 87M25, it is sufficient to arrange the adjustment track centers 11 to 14 of alignment disk 1 shown in FIG. 2 so as to correspond to each phase of 87M25. In this embodiment, tracks 16, 19, 2
It was set to 2.25.

Also, Fig. 5 shows the amount of off-track when the 87M25 shown in Fig. 4 is actually incorporated into a magnetic disk drive.
A superimposed curve of static angle error and cumulative error of 7M25 is obtained. Generally, the tendency of this cumulative error does not change minutely, so the center 10.15 of the adjustment track of the alignment disk 1 in Fig. 2 is set near the outermost circumference and near the innermost circumference, and the off-track on these two adjustment tracks is set. 9. In this embodiment, in order to distinguish it from the static angle error of 87M25, track 1 of the same phase is I set the center of this adjustment track to 37.

Next, align the magnetic disk drive with alignment disk 1.
For example, when adjusting and verifying using show. Here, (a) is the reproduction signal of the upper head, (b) ゜・2, is the filter output signal of the upper head, (c) is the reproduction signal of the lower head, and (d) is the filter output signal of the lower head. and each symbol (Tt, Tt.

Vnυ^, etc.) corresponds to the value or address taken into the personal computer 7 by the A/D converter 5 in FIG.

(1) The track diameter direction is the output ratio of the inner circumference side signal 17 and the outer circumference side signal 18 of track diameter adjustment signal 6.
/V FIL[l and V nu^/V Run, the error with respect to the specified track radial direction position can be determined.

(2) In the index timing direction, set a constant time interval for A/N conversion, start AID conversion from the TDX point, and count the memory addresses of the personal computer 7 corresponding to the rise of the index timing adjustment signal 22. By displaying on the screen, T1. Tz
We can arrange and verify that the time falls within the allowable value of the specified time T.

(3) The azimuth direction is a CW multiplied signal 20 of the azimuth adjustment signal 19. V OLA / which is the output ratio of the CCV signal 21
From the relationship between V at, a and V 0IJA / V oun, it is possible to adjust and verify whether the azimuth angle of the R/W gap of the upper and lower heads of the magnetic head 29 is within the allowable value.

As the next example, the magnetic head 29 reproduces the track NL11 near the outermost circumference; iIl! l! s! FIG. 7 shows a waveform obtained by filtering the signal through the filter 4 of FIG. 1.

The upper side shows waveforms caused by the upper head of the magnetic head 29 and the lower head on the lower side.

(1) Error ΔL from the specified track radial position.

80 Ha, 8 pairs per lap (7) (V*i, ^) t/ (
VFILB) t and (VIIUA) J/ (VnuB
) By using the value of J and the R/W gap width W of the magnetic head 29, it can be expressed as follows. Therefore, the off-track error caused by the static angle error of the STM 25, the hysteresis error due to the feeding direction, and the vertical assembly error of the magnetic head 29 can be displayed and verified.

(2) The error between the track Nα1°Nα25, which is the same excitation phase of the STM 25, and the track radial position in the blood 37 is Δt, Δx11. Assuming Δ87, the cumulative error can be approximated by a straight line, so if (Δ37-Δ26) and (Δ28-Δ1) have the same sign, Δ87-Δl is the larger value (Δ87-Δ26) and (Δz3-Δ1) have the same sign. If so, it can be expressed as the larger value. Therefore, it is also possible to display and verify cumulative errors.

(3) Eight pairs of (Vnshi^), /(
VRLB) t or (VRIJA) J/ (VRU
B) Due to the difference between the maximum and minimum ratio of J, the magnetic disk 2
The chucking error α, which is the error of the eccentric component during soil removal when chucking 4, can also be determined by the following.

Next, an example in which the errors described above are collectively displayed on the CRT of the personal computer shown in FIG. 1 will be explained based on FIG. 8.

In the figure, at””aa is track N (116, 19
22.25 represents the error with respect to the track radial direction position and the chucking error, 81 to a4 represent the lower head error, and a5 to a8 represent the upper head error. Here, the left part Q1 of each diamond is the error when moving in the inner circumferential direction, and the right part Q2
represents the error when moving the outer circumference. Therefore, the hysteresis error is expressed by the difference 0δ between Ql and Q2, and the parenthesis chucking error is expressed by the length of Ql or Q2.

Further, the vertical assembly error of the magnetic head 29 can be determined by the difference between the Fil of the same track, for example &1, 6, and A5.
The variation in static angle error due to the excitation phase of TM is a1~A
It can be understood by the 4th place @ relationship. Finally, a(1 is used to indicate the sum of the cumulative error and the track radial position error. Here, Qe represents the maximum value of the track radial position error in the four tracks shown on the right side of Figure 1. °C, Q4
and Q6 are the cumulative errors obtained from tracks -1, 25, and 37, and Q4 and Q6 are respectively (Δ87 - Δ26) in the previous section.
and (8215-Δ1). That is, the result of adding up the respective sizes of Q4 to Q6 indicates the total positional error determined by the 7-alignment disk in the track radial direction of the magnetic disk device. Based on this value, it can be determined whether the position adjustment of the head carriage drive unit is within the allowable value.

Further, the index timing direction and the azimuth direction are displayed numerically or graphically as necessary.

According to this embodiment, (1) Accuracy of position adjustment (2) STM static angle error, hysteresis error.

Accumulated errors in the transmission system (3) The chucking error of the magnetic disk and the assembly error of the upper and lower magnetic heads can be displayed all at once on the screen. By verifying products that are designed with the required accuracy in mind based on probability distribution at the assembly level, the positional adjustment error of the head carriage drive unit can be determined for each magnetic disk drive, allowing adjustments to be made with the necessary and sufficient accuracy. This eliminates the need for unnecessary adjustment time and has the effect of improving productivity, improving reliability, and stabilizing the system. In addition, if a sufficient adjustment tolerance cannot be obtained, it becomes clear which component is defective or has been assembled incorrectly, which has the effect of improving productivity and reliability during reassembly.

〔Effect of the invention〕

According to the present invention, as adjustment and verification in the track radial direction,
11. Chucking error, which is an error of eccentric component that occurs when chucking a magnetic disk, vertical assembly error of the magnetic head, and static error of the stepping motor. ．． The angle error, the hysteresis error due to the feeding direction, and the cumulative error of the transmission system accumulated at each step from the inner circumference to the outer circumference can be displayed numerically or graphically on the screen. Therefore, by verifying at the assembly level the results of the accuracy of each component of the magnetic disk drive having a probability distribution with respect to each other, the position adjustment error of the head carriage drive unit can be determined for each magnetic disk drive. Productivity is improved by eliminating the need for unnecessary adjustment time.

It has the effect of improving reliability and stabilizing it. Furthermore, if the adjustment does not fall within the tolerance, it becomes clear that the accuracy of the component parts is poor or that there is a defective assembly, which has the effect of improving productivity and reliability during reassembly.

In addition to the above adjustment and verification in the track radial direction, data in the index timing direction and the inclination direction of the R/W gap of the magnetic head can also be displayed on the CRT at the same time, making highly accurate adjustment and verification possible and supporting higher density. The reliability can be improved.

[Brief explanation of drawings]

FIG. 1 is a principle diagram of a tracking adjustment device for a magnetic disk drive device showing an embodiment of the present invention, and FIG. 2 is a diagram of the M of FIG.
3 is a perspective view of the magnetic drive device adjusted by the adjustment device shown in FIG. 1, FIG. 4 is a characteristic diagram showing the static angle error of STM, and FIG. 5 is a front view of the alignment disk used in the W device.
The figure is a characteristic diagram showing the amount of off-track when incorporated into the STMti-magnetic disk drive shown in Figure 4, Figures 6 and 7 are diagrams showing the playback output of the alignment disk signal, and Figure 8 is a diagram showing the present embodiment. Figure 9 is a front view of a conventional alignment disk, Figure 10 is a diagram showing the captured data displayed on a CRT.
The figure is an explanatory diagram of the principle of a conventional tracking adjustment device 4. DESCRIPTION OF SYMBOLS 1... Alignment disk, 2... Magnetic disk drive device, 4... Filter, 5... A/r) converter, 7. Kita 5/Ri 8 --- Conf-a-le [2] 呵 1 6th 7th riJ

Claims (1)

[Claims] 1. A magnetic head comprising at least a magnetic head for recording and reproducing data on a magnetic recording medium, a carriage on which this magnetic head is mounted, and a drive device for moving this carriage in the track radial direction on the magnetic recording medium. A magnetic disk that positions the magnetic head in a predetermined track radial direction by using the magnetic head to read adjustment signals from a removable alignment disk on which adjustment signals are recorded, in order to ensure data compatibility of the disk drive device. In a tracking adjustment device for a drive device, a sequence for automatically moving the carriage from an outer circumference to an inner circumference and from an inner circumference to an outer circumference in at least one track, and filtering a read signal of the magnetic head. filter, an A/D converter that converts the output of this filter into a digital signal, and this A/D converter that converts the output of this filter into a digital signal.
A storage means for storing the output of the D converter is provided, and the data in this storage means is processed by a calculation means to calculate the vertical error of the magnetic head, the static angle error of the drive device, the hysteresis error due to the moving direction of the carriage, etc. A tracking adjustment device for a magnetic disk drive device, characterized in that it is possible to display one or more of an accumulated error accumulated at each step from the periphery to the outer periphery, and an eccentric error. 2. In claim 1, the carriage is automatically moved from the outer periphery to the outer periphery and from the inner periphery to the outer periphery in tracks that are greater than or equal to the number of excitation phases of the drive device and that correspond to at least each excitation phase. 1. A tracking adjustment device for a magnetic disk drive device, characterized in that a sequence for moving the magnetic disk drive device is provided. 3. In claim 2, in addition to the tracks corresponding to each excitation phase of the drive device, in one or both of the tracks near the outermost circumference side and the innermost circumference side in the track radial direction, A tracking adjustment device for a magnetic disk drive device, characterized in that a sequence is provided for automatically moving the carriage from the outer circumference to the inner circumference and from the inner circumference to the outer circumference. 4. In the case of an alignment disk in which an azimuth signal for detecting the inclination of the recording/reproducing gap of the magnetic head is also recorded at the same time, the inclination of the magnetic head can also be displayed. A tracking adjustment device for a magnetic disk drive device according to item 1 or 2. 5. Alignment signal that also records the index timing adjustment signal for detecting the rotational position of the magnetic head.
In the case of a disk, the tracking adjustment device for a magnetic disk drive device according to claim 1 or 2, characterized in that the rotational direction position from the reference position of the magnetic head can also be displayed.