JPH039525B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an alignment disk for a double-sided head drive, and more particularly to an alignment disk used for adjusting upper/lower head assemblies or drive assemblies in a magnetic disk drive device.
This invention relates to an alignment disk for double-sided head drives that is suitable for high-density drive devices of 100 TPi (tracks per inch) or more and allows for highly accurate adjustment work.

[Background of the invention]

A conventional example is the Japanese Patent Publication No. 59-1989 filed by BASF.
A track diameter adjustment signal was written in the "magnetic recording disk for adjustment and control" described in Publication No. 7142, and it was possible to adjust the track diameter direction in the drive device.

However, it does not generally include all the track diameter adjustment signals, index timing adjustment signals, azimuth adjustment signals, etc. necessary for data compatibility in a magnetic disk drive device. Therefore, it can be said that the data compatibility of the high-density drive device is still not fully guaranteed, and there is still room for further improvement.

Next, another conventional example will be explained using FIG. 5, which is a plan view showing the arrangement of signals on an alignment disk according to the conventional example.

That is, in the alignment disk 50, an index timing adjustment signal 51 is provided on the track on the outer circumferential side, and a track diameter adjustment signal 52 is provided on the center track to make it eccentric from the center axis 53 by approximately ε=0.1 mm, which is a specified dimension. Approximately δ/2 from the reference diameter
A large-diameter signal 54 that is larger by =0.075 mm and a small-diameter signal 55 that is smaller by the same dimension are provided, and the azimuth adjustment signal 56 is applied to the inner track, and the CW signal 5 is detected using a so-called cat's eye signal detection method.
7. It is provided by the CCW signal 58, and IDX is the index timing detection point.

Note that a CW signal is a signal that is angled clockwise, and a CCW signal is a signal that is angled counterclockwise.

Also, on the back side of the alignment disk 50,
Almost the same signals are written.

If this method is used, it is possible to check the adjustment of the drive assembly. Adjustment signals in the axis timing direction (Y direction) and azimuth direction (θ direction) are each stored in separate tracks, especially for the 100TPi class, which is highly dense and requires assembly accuracy in the X, Y, and θ directions. When assembling the upper/lower head assemblies for the above, for example, fine adjustments in the X direction often cause changes in the Y and θ directions, and it takes a long time to assemble to the required assembly accuracy. In addition, when trying to improve assembly accuracy, assembly time increases exponentially, making it impossible to achieve assembly accuracy above a certain level, which is why improvements are desired from the perspective of improving productivity. This is what I used to do.

[Purpose of the invention]

In order to assemble and adjust upper/lower head assemblies for 100TPi class or higher with high productivity, the present invention has been developed to meet the above requirements and to assemble and adjust upper/lower head assemblies for 100 TPi class or higher with high productivity. ), the adjustment signals in the azimuth direction (θ direction) are arranged appropriately so that, for example, changes in the Y and θ directions caused by fine adjustment in the X direction can also be detected at the same time. The object of the present invention is to provide an alignment disk for a double-sided head drive, which can shorten assembly time and improve assembly accuracy by eliminating the effects of errors during alignment disk chucking that occur when the disk is chucked.

[Summary of the invention]

The structure of the alignment disk for a double-sided head drive according to the present invention is such that the alignment disk for a double-sided head drive adjusts at least a magnetic disk drive having two heads on an upper surface and a lower surface with respect to one disk. As the diameter adjustment signal, an inner side signal and an outer side signal that extend geometrically alternately to the inner side and the outer side from the specified adjustment signal track center line are arranged, and (b) an index timing adjustment signal. As,
A timing signal that appears after a specified time after index timing detection is placed on the center line of the adjustment signal track, and (c) as an azimuth adjustment signal, each radius line extending from the center axis on the center line of the adjustment signal track and the time rotation are arranged. The alignment disk is arranged such that a CW signal written by the R/W head having a prescribed intersection angle and a CCW signal written by the R/W head having a prescribed intersection angle in a counter-time direction are arranged, The signals (a), (b), and (c) are provided on both the upper and lower surfaces of the disk, and as the track diameter adjustment signals, the specified adjustment signals are arranged geometrically alternately on the inner circumference from the track center line. 4 to 96 pairs of the inner side signal and the outer side signal arranged extending to the outer side are provided symmetrically with respect to the center axis, and as the azimuth adjustment signal, the adjustment signal is centered on the track center line. R/W that has a specified intersection angle with each radius line extending from the time line
The CW signal written in the head and the R/W signal written in the R/W head, which has a specified intersection angle in counter-time direction.
The arrangement of the CCW signals is characterized in that 4 to 96 sets of the CW signal and the CCW signal are arranged symmetrically with respect to the central axis.
In the present invention, the numbers of the track diameter adjustment signals and the azimuth adjustment signals are set to 4 to 96 pairs and 4 to 96 pairs, respectively, by selecting a practical range through trial production experiments.

[Embodiments of the invention]

Embodiments of the alignment disk for a double-sided head drive according to the present invention will be described with reference to the drawings.

First, FIG. 1 is a plan view showing the arrangement of signals on an alignment disk for a double-sided head drive according to an embodiment of the present invention, and FIG. 2 shows the arrangement of signals when using the alignment disk of FIG. 1. FIG. 6 is a state diagram showing the reproduced waveforms of the upper and lower head assemblies on an oscilloscope.

In FIG. 1, on the adjustment signal track center line 2 of the alignment disk 1 for a double-sided head drive, there is a track diameter adjustment signal 10 according to (A).
Eight pairs of inner circumferential side signals 11 and outer circumferential side signals 12 extending geometrically alternately to the inner circumferential side and the outer circumferential side from the adjustment signal track center line 2 are provided center-symmetrically with respect to the central axis 3.

Furthermore, as the index timing adjustment signal 20 related to (b), on the adjustment signal track center line 2,
After a specified time T (see Figure 2) from the index timing detection point (IDX) 22, the timing signal 2
1 is placed.

Further, as the azimuth adjustment signal 30 related to (c), on the adjustment signal track center line 2, each radius line l extending from the center axis 3 and the R/W head having prescribed intersecting angles α', α in the time direction are used. Written CW
The signal 31 and the CCW signal 32 written by the R/W head having prescribed intersecting angles α and α' in the counterclockwise direction are set as one block pair, and eight pairs are arranged alternately with the above eight pairs of track diameter adjustment signals 10. be.

The above-mentioned intersection angles α' and α are the angles formed between the line connecting the central axis 3 and each radius line l and the longitudinal line of the gap of the signal writing head.

Further, substantially the same signals are written on the back side of the alignment disk 1 for a double-sided head drive.

The alignment disk 1 for a double-sided head drive with this configuration is constructed by a signal writing device 6 shown in FIG. 6, which is a schematic perspective view of the alignment signal writing device.
Signal writing is performed by 0.

That is, the alignment disk 1 for a double-sided head drive is checked by a hub receiving part 62 that is rotatably supported by a shaft 61, and the distance L between the center of the shaft 61 and the signal writing head 65 is optically measured using a length measuring device A64. Another length measuring machine B6 is used so that the dimensions can be measured with the double-sided head drive alignment disk 1 attached to the signal writing device 60 during writing.
3 are arranged as a signal writing device 60 with high reproducibility.

Here, a case will be described in which the alignment disk 1 for a double-sided head drive shown in this embodiment is used to adjust the upper/lower head assembly 70 shown in FIG. 7.

7(A) is a side sectional view of the upper/lower head assembly, and FIG. 7(B) is a perspective view in the P direction of FIG. 7(A).

That is, FIG. 7 shows the upper/lower head assembly 7.
0, the assembly accuracy required in the 100TPi class is P
The lower head 71 and upper head 72 are shown in a perspective view in the track radial direction (X direction).
x = within ±10 μm, index timing direction (Y direction) is within y = ±50 μm, azimuth direction (θ direction) is based on the radius line l extending from the center axis 3, and the gap of the R/W core is set to θ. _L , θ _U =±
It is necessary to assemble the adjustment within 12′.

Therefore, the upper/lower head assembly 70 to be adjusted is assembled into the adjustment drive, and the alignment disk 1 for double-sided head drive is attached.
If the output from each of the upper and lower heads is displayed on the oscilloscope 40, the pattern of the first part (1/8th round) from the index timing is as follows.
The result is shown in Figure 2.

Although it went back and forth, the upper side of Figure 2 is the upper head.
The lower part electrically displays the positional relationship of the lower heads, allowing the following to be determined.

(a) In the track radial direction (X direction), V _RLA / V _RLB
Based on the relationship between V _RUA / V _RUB , is it permissible for x = ±10 μm?

(b) The index timing direction (Y direction) is
From the deviation amount Δt at the upper and lower heads of the rising point of the timing signal 21, is it permissible for y to be within ±50 μm?

(c) The azimuth direction (θ direction) is V〓 _LA /V〓 _LB.
From the relationship with V〓 _UA /V〓 _UB , is it permissible for the azimuth angles of the R/ _W gap of the upper and lower heads to be within ±12 _' ?

Therefore, assembly accuracy in the X, Y, and θ directions can be displayed on a single oscilloscope 40.

Typically, upper/lower head assemblies include X, Y, θ
For example, when fine-tuning the direction, for example, if you fine-tune the X direction, the accuracy in the Y and θ directions will also change, so it is possible to check the X, Y, and θ directions simultaneously on the same oscilloscope 40. teeth,
The time required to temporarily assemble and adjust the upper and lower heads can be significantly shortened, and it is also possible to achieve higher precision assembly, which is required when the density is higher than the 100TPi class.

For example, in the 100 TPi class, the conventional method shown in Fig. 5 described above takes 20 to 30 minutes to adjust one upper/lower head assembly to the assembly accuracy shown in Fig. 7. However, in the method using the double-sided head drive alignment disk shown in FIG. 1 according to this embodiment, the required time can be significantly shortened to 3 to 10 minutes.

By the way, as shown in Fig. 8, in general, the central axis _O1 when manufacturing the alignment disk is not the same as the central axis _O2 when actually adjusting a double-sided head drive using this alignment disk. , an error δ occurs during alignment disk tracking. Therefore, if the recorded radius of alignment signal A is r, the signal at point A' has an angular error of θ=tan ^-1 (r/δ). occurs in the azimuth adjustment signal. By the way, as a specific example, if you calculate with 3-inch CFD standard track 39, r ₃₉ =
Assuming 22.594mm and tracking error δ=0.01mm,
This results in an azimuth angle error of θ = tan ^-1 (0.01/22.594) = 1.5'. This is a non-negligible amount for the assembly accuracy of double-sided head drives of ±12'.
Generally, in order to maintain compatibility with double-sided head drives, assembly accuracy must be tightened to ±10.5'.
It cannot be denied that extra assembly and adjustment time will be required.

On the other hand, in the present invention, as shown in FIG. 4 to 96 pairs of the inner circumferential side signal 11 and outer circumferential side signal 12 are provided symmetrically with respect to the central axis 3, and further, as the azimuth adjustment signal 30, the adjustment signal is centered on the track center line 2. A CW signal 31 written by the R/W head having specified intersecting angles α, α' in the clockwise direction with respect to each extending radius line l, and a CW signal 31 written by the R/W head having specified intersecting angles α, α' in the counterclockwise direction. The corresponding CW signal 3 in the arrangement of the CCW signal 32
1 and CCW signal 32 as one set, 4 to 96 sets,
It is provided centrally symmetrically with respect to the central axis 3, and by using the average value of the 4 to 96 sets of azimuth adjustment signals 30, the angular error that occurs in the azimuth adjustment signal 30, that is, the double-sided head using an alignment disk. It is possible to eliminate the influence of errors during alignment disc chucking that occur when adjusting the drive.

Next, FIG. 3 is a plan view showing the arrangement of signals on an alignment disk for a double-sided head drive according to another embodiment, and FIG. FIG. 6 is a state diagram showing the reproduced waveforms of the upper and lower head assemblies on an oscilloscope.

3, in addition to the adjustment signal track center line 2 shown in FIG. 1, an adjustment signal track center line A4 is provided, and on this adjustment signal track center line A4 there is a signal 10
It is characterized by the fact that only

If the upper/lower head assembly 70 is moved on the adjustment signal track center line A4 according to this embodiment, the signal of one rotation of the alignment disk 1A for double-sided head drives will be used to display the fourth position on the oscilloscope.
Signals only in the track radial direction (X direction) of the upper/lower head shown in the figure are displayed, and pattern recognition is used to detect signals in the track radial direction (X direction) where the highest accuracy is required.
It is possible to easily determine the accuracy of x=±10 μm (direction).

In addition, in FIG. 1, the specified time T related to the index timing adjustment signal is defined as follows.
Although a special signal is provided, for example, the rising point of the track diameter adjustment signal 10 or the rising point of the azimuth adjustment signal 30 can also be used as the prescribed time T.

Furthermore, although the embodiment of FIGS. 1-4 describes the adjustment of the upper/lower head assembly 70, this
Of course, it can also be used for adjustment and inspection of the drive assembly at the same time.

According to the above embodiment of the present invention, on the adjustment signal track center line 2, which is one track of the alignment disks 1 and 1A for double-sided head drives, the track radial direction (X direction) and the index timing direction (Y direction) are aligned. ), azimuth direction (θ direction)
Adjustment signals in three directions are written,
The assembly accuracy required for upper/lower head assemblies used in high-density drive devices of 100TPi or more can be displayed on a single oscilloscope. Since the adjustment accuracy can be fed back, the time for assembling and adjusting the upper/lower head can be significantly shortened, and in addition, the high-precision upper/lower head can be used even if higher density is required in the future. It is possible to provide assembled products.

Furthermore, it is of course possible to adjust and inspect the drive assembly using the same double-sided head drive alignment disk.

〔Effect of the invention〕

According to the present invention, in order to assemble and adjust upper/lower head assemblies for 100TPi class or higher with high productivity, the upper/lower head assemblies for 100TPi class or higher can be assembled and adjusted in the track radial direction (X direction) on the same track.
By properly arranging the adjustment signals in the index timing direction (Y direction) and azimuth direction (θ direction),
For example, it is possible to simultaneously detect changes in the Y and θ directions caused by fine adjustments in the It is possible to provide an alignment disk for a double-sided head drive that can reduce time and improve assembly accuracy, and can be called an invention with excellent practical effects.

[Brief explanation of drawings]

FIG. 1 is a plan view showing the arrangement of signals on an alignment disk for a double-sided head drive according to an embodiment of the present invention, and FIG. , FIG. 3 is a plan view showing the arrangement of signals on the alignment disk for a double-sided head drive according to another embodiment, and FIG. Figure 3 is a state diagram showing the reproduction waveform of the upper/lower head assembly to be adjusted on an oscilloscope when using the alignment disk, and Figure 5 is a plane showing the arrangement of signals on a conventional alignment disk. Figure 6 is
Schematic perspective view of alignment signal writing device, seventh
Figure (a) is a side sectional view of the upper/lower head assembly, and (b) is a side sectional view of the upper/lower head assembly.
8 is a perspective view in the P direction of (A), and FIG. 8 is a partial plan view for explaining the error when adjusting the alignment disk when adjusting the double-sided head drive using the alignment disk for the double-sided head drive. be. 1,1A...Alignment disk for double-sided head drive, 2...Adjustment signal track center line, 3
...Center axis, 4...Adjustment signal track center line A,
10... Track diameter adjustment signal, 11... Inner circumference side signal, 12... Outer circumference side signal, 20... Index timing adjustment signal, 21... Timing signal,
22... Index timing detection point (IDX),
30...Azimuth adjustment signal, 31...CW signal,
32...CCW signal, l...Radius line, α, α'...
Specified intersection angle, 40...Oscilloscope, 60...
Signal writing device, 61...shaft, 62...
Hub receiver, 63...Length measuring machine B, 64...Length measuring machine A, 65...Signal writing head, 70...Upper/lower head assembly, 71...Lower head, 72...Upper head, O ₁ ... Central axis when manufacturing the alignment disk, O ₂ ... Central axis when adjusting the double-sided head drive, δ... Error when checking the alignment disk, A, A'... Alignment signal,
r...Radius where the alignment signal is recorded,
θ...Azimuth angle error.

Claims (1)

[Claims] 1. At least in an alignment disk for a double-sided head drive that adjusts a magnetic disk drive having two heads, an upper surface and a lower surface, for one disk, (a) a specified track diameter adjustment signal; The inner side signal and the outer side signal are arranged geometrically alternately extending to the inner side and the outer side from the adjustment signal track center line, and (b) the index timing adjustment signal is arranged on the adjustment signal track center line. The timing signal is arranged so that it appears after a predetermined time has elapsed after the index timing is detected, and (c) the azimuth adjustment signal is arranged so that it appears on each half meridian extending from the center axis on the adjustment signal track center line and around the time. R/ with intersection angle of
An alignment disk in which a CW signal written in the W head and a CCW signal written in the R/W head having a prescribed intersection angle in the counter-time direction are arranged, and the alignment disk comprises the above (a), (b), The signals in (c) are provided on both the upper and lower surfaces of the disk, and as the track diameter adjustment signals, the prescribed adjustment signals are arranged geometrically extending alternately from the track center line to the inner and outer circumference sides. 4 to 96 pairs of inner side signals and outer side signals are provided symmetrically with respect to the center axis, and as the azimuth adjustment signal, each radius line extending from the center on the adjustment signal track center line and a time rotation are provided. A set of the CW signal and CCW signal in the arrangement of the CW signal written by the R/W head with a specified intersection angle and the CCW signal written by the R/W head with the specified intersection angle counterclockwise. An alignment disk for a double-sided head drive, characterized in that 4 to 96 sets are provided centrally symmetrically with respect to a central axis. 2. In what is stated in claim 1,
As the index timing adjustment signal, the timing signal is arranged so that it appears on the adjustment signal track center line after a specified time after the index timing is detected.The specified time is the signal rising point of the track diameter adjustment signal or azimuth adjustment signal. Alignment disk for double-sided head drives. 3 In what is stated in claim 1,
In addition to providing a track diameter adjustment signal, an index timing adjustment signal, and an azimuth adjustment signal on the adjustment signal track center line, another adjustment signal track center line is provided on another track, and the other adjustment signal track center line is provided on the center line of this another adjustment signal track. This is an alignment disk for double-sided head drives that only has track diameter adjustment signals.