JPS60133520A - Adjusting device of magnetic head - Google Patents

Abstract

PURPOSE:To obtain a magnetic head adjusting device reducing the cost of adjustment by recording a prescribed signal in a magnetic recording medium by a recording means and reference heads adjusting a signal reproduced by a magnetic head to be adjusted and a reproducing means so as to be a prescribed output. CONSTITUTION:The magnetic recording medium 1 is rotated by a motor 2, an index signal generating circuit 19 generates an index signal in accordance with the rotation of the motor 2, and synchronously with said index signal, a pulse generating circuit included in a recording circuit 17 generates a prescribed signal, which is amplified, supplied alternately to reference heads 4, 5 through an alteration switch 18 and recorded in the recording medium 1. The recorded signal is reproduced by the magnetic heads 10, 12 to be adjusted and sent to an oscilloscope 21 through reproducing circuits 20a, 20b and the positions of the heads 10, 12 are adjusted by a head carriage 16 so that the reproduced signal becomes a prescribed output. Thus, the adjusting cost is reduced.

Description

[Detailed Description of the Invention] Industrial Field of Application (The invention relates to a magnetic head adjustment device for adjusting the position of a pair of magnetic heads (double-sided heads) facing each other on the top 1' of a magnetic disk drive. It is.

Conventional configurations and their problems In general, duplex heads are adjusted in the following three areas. The first is to adjust the angle J, that is, the azimuth angle, between the upper and lower hen-dog gab and the radial direction relative to the rotation center of the magnetic disk.Second, the position of the upper hen-dog gab is adjusted to the lower side. A predetermined distance, for example, 4 tracks (or 81-racks) from that of the magnetic disk, that is, radial position adjustment with respect to the rotation center of the magnetic disk
, Thirdly, adjustment of the tangential direction of both the upper and lower heads with respect to the center of rotation of the magnetic disk, in other words, this is for signal reading and
It is called timing adjustment because it is related to write timing.

The above three items have conventionally been adjusted using a magnetic disk called a CE disk on which reference signals are recorded.

On this CE disk, signals called azimuth burst for adjusting the azimuth angle, cat's eye for radial adjustment, and index burst for timing adjustment are recorded. Among the above three reference signals recorded on this GE disk, the cat's eye signal in particular requires special recording by rotating the magnetic disk around a point that is eccentric by a predetermined amount from the regular center of rotation. A writing machine is required. Therefore, GE disks are expensive.

Furthermore, CE disks are consumable items, and their lifespans end after adjustments to several hundred units.

That is, the conventional magnetic head adjustment using a CE disk has the disadvantage that the adjustment cost is high.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and an object of the present invention is to provide a magnetic head adjustment device that can reduce adjustment costs.

SUMMARY OF THE INVENTION In order to achieve the above object, a magnetic head adjusting device of the present invention includes: a rotation drive means for rotating a magnetic recording medium at a predetermined speed; at least one pair of reference heads vertically opposed; A recording device for recording a predetermined signal on both sides of a recording medium, and a reproducing device for reproducing and amplifying signals from a pair of vertically opposed magnetic heads to be adjusted, and the recording device and the reference head record a predetermined signal on the magnetic recording medium. A predetermined signal is recorded on the adjusted magnetic head, reproduced by the rad d3 and reproducing means, and the adjusted magnetic head is adjusted so that the reproduced signal becomes a predetermined output.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a magnetic head adjusting device according to a first embodiment of the present invention, in which 1 is a magnetic recording medium, 2 is a motor that rotates the magnetic recording medium 1 at a predetermined speed, and 3 is a motor. 2 is a drive shaft, 4 is a lower reference head, and 5 is an upper reference head.

The lower reference rod 4 is attached to the lower reference rod arm 6, and the upper reference rod 5 is attached to the upper reference rod arm 7. The upper reference rad arm 7 is fixed to the lower reference rad arm 6 via a spring member 8. Further, the lower reference rad arm 6 is fixed to the stage 9. The azimuth and index timing of the RAD 4 to the lower reference and the RAD 5 to the upper reference are precisely adjusted with respect to the rotation center of the magnetic recording medium 1, and the RAD 5 to the upper reference is adjusted to the lower reference. Rad 4
It is precisely adjusted to the 4-track (or 8-track) direction. The stage 9 is movable in the radial direction and the tangential direction with respect to the rotation center of the magnetic recording medium 1. Therefore, the upper and lower IT rods 4.5 can be moved in the radial and tangential directions with respect to the rotation center of the magnetic recording medium 1 while maintaining their relative positions. 10
12 is a lower adjusted magnetic head, and 12 is an upper adjusted magnetic head, which are attached to the lower adjusted Radar arm 11 and the upper adjusted Radar arm 13, respectively. This upper adjustable head arm 13G is fixed to the lower adjusted head arm 11 via a spring member 14. This fixation is done by a screw 15, and by loosening this screw 15, the position of the rad 12 is adjusted to the lower side to be adjusted. The upper adjusting arm 11 is fixed to the adjusting carriage 1G and can move in the radial direction with respect to the rotation center of the magnetic recording medium 1, and simultaneously moves the adjusting magnetic head 10.12 in the radial direction.

FIG. 2 is a block diagram of an electric circuit of a magnetic head adjustment device according to an embodiment of the present invention, in which 17 is a recording circuit composed of a pulse generation circuit, an amplifier circuit, etc., and 18 is a changeover switch. , the recording circuit 17 is switched to supply the signal (g) to Rad4 to the lower reference or Rad5 to the upper reference.19
The index circuit 1 generates a rotation signal, that is, an index signal as the magnetic recording medium 1 rotates. A part of this index signal is supplied to the recording circuit 17 to determine the timing of the start of signal recording. give 20a
, 20b is re.

These are raw circuits, and the outputs of the lower adjusted magnetic head 10 and the upper adjusted magnetic head 12 are supplied for reproduction and amplification. The reproduction outputs of the reproduction circuits 20a and 20b are supplied to an oscilloscope 21 and observed. The index signal generated by the index signal generation circuit 19 is also supplied to the oscilloscope 21, and is used as a trigger signal for displaying the reproduced output.

Next, the operation will be explained. The magnetic recording medium 1 is rotated by a motor 2 via a drive shaft 3 at a predetermined constant speed. ,
In response to the rotation, the index signal generation circuit 19 generates an index signal. In synchronization with this index signal, the pulse generating circuit included in the recording circuit 17 generates a predetermined signal, which is amplified by the amplifier circuit included in the recording circuit 17, and then transferred to the reference 4, 5 and recorded on the magnetic recording medium 1.

The signals recorded here are reproduced by the magnetic head to be adjusted 10.12, amplified by reproduction circuits 20a and 20b, and supplied to an oscilloscope 21. Then, the head kittridge 16 adjusts the position of the rad 10 to the lower magnetic field to be adjusted so that the reproduced signal becomes a predetermined output, and the screw 1
5 to adjust the position of the upper head arm 13 to be adjusted. The fact that the reproduced signal has a predetermined output no.j means that J
In other words, the relative position of the magnetic heads 10, 12 to be adjusted has become the same as the relative position of the reference head 4.5, and the position of the magnetic head 10.12 to be adjusted has been adjusted.

In the above explanation, the stage 9 is not used and the reference head 4 is
．． 5 remains fixed and adjusts Rad 10°12 to the adjusted target. For example, in the radial adjustment and azimuth adjustment, a predetermined signal, for example, a signal of 125Kl-tz, is recorded over one revolution of the magnetic recording medium 1 by the recording circuit 17 and the reference radar 4°5, and then reproduced with the head to be adjusted 10.12. circuit 2
The head to be adjusted 10.12 is adjusted so that the signal recoused by signals 0a and 20b is maximized. In addition, timing adjustment is performed by recording a predetermined signal in a burst form in synchronization with the index signal, and by recording the same 1WJ signal in synchronization with the index signal.
Then, the reproduced signal is observed by the oscilloscope 21, and the position of the adjusted head 10.12 can be adjusted so that the burst signal is reproduced at a predetermined timing.

Next, a signal format suitable for highly accurate position adjustment, its recording method, and adjustment method will be explained.

FIG. 3 shows an example of recording signal and reproduction signal waveforms of the magnetic head adjustment device in an embodiment of the present invention.
a and b are azimuth burst recording signals, and C is a reproduction signal. The azimuth burst recording signals a and b are recorded at predetermined angles in the clockwise and counterclockwise directions, respectively, with a gap of 4.5 rad relative to the reference in the radial direction relative to the rotation center of the magnetic recording medium 1. . This angle is constructed relatively by shifting the reference head 4.5 tangentially with respect to the center of rotation of the magnetic recording medium 1. Reference head 4.
5 is moved in the tangential direction by a stage 9.

The relationship between the movement ff1d in the circumferential direction and the angle α of the gap with respect to the radial direction is −1 cl, where γ is the recording radius. A suitable value for α is about ten minutes.

Azimuth burst record recorded in this way
, b in and out of the adjusted head 10.12, when the direction of the gap is adjusted correctly, the amplitudes of both burst signals become equal, as shown in FIG. 3C. However, if the gap is even slightly clockwise or counterclockwise, e.g. 2 to 3
If there is a difference of even a minute, the balance between the amplitudes of both bursts will be lost. Therefore, by adjusting the head 10.12 to be adjusted so as to obtain a reproduced waveform as shown in FIG. 3C, the azimuth adjustment of the head 10.12 to be adjusted can be performed.

FIG. 4 shows an embodiment of the present invention. ! 7 shows another example of a recording signal pattern and a reproduced waveform of the head adjustment device. In FIG. 4, a indicates a recording signal pattern for performing radial adjustment, in which burst signals are recorded alternately on the outside and inside of the magnetic recording medium 1 with a predetermined raw silk R as the boundary. To generate such a signal, first shift the Radius 4 and 5 from the position of a predetermined radius R to the outside by 1-rack width (half the width of the heel) and record the burst depths 301 to 04... , then record the burst signals @ e1 to e4 by shifting inward from the position of the predetermined radius R, which is half the track width.
, 5 are moved in the radial direction by a stage 9. The signal recorded in this way is transferred to the adjusted magnetic field by 10°12 rad.
Play with. Now, if the helad 10 is at the position of radius R as shown by the broken line, the burst signal O recorded on the outside
Burst signal e1~ recorded inside as 1~O4...
The amount by which e4... is raced to 1 is the same, resulting in reproduced waveforms with the same amplitude as shown in FIG. However, if the helad 10 deviates outward from the radius R as shown by the solid line,
The outer burst signals @01-o4... are raced more than the inner burst signals e1'-e4...°, resulting in a reproduced waveform as shown in FIG. 4C. Also, if the head 10 is shifted inward, the inner burst signals e1 to e4... will be sent to the outer burst 1 as signals 01 to O4.
. . ., the reproduced waveform is as shown in FIG. 4d. Therefore, by adjusting the adjusted magnetic head 10.12 so that the reproduced waveform becomes as shown in FIG. 4, the adjusted head 10. 12 relative positions can be adjusted. This adjustment is performed for the lower head to be adjusted 1O using the head sharpening ridge 1G, and for the upper adjustment head 12 by loosening the screw 15. Using the signal pattern described above, radial adjustment can be performed with high accuracy of 2 to 3 μm.

To adjust the timing of the magnetic head 10.12 to be adjusted, a burst signal is recorded by the rads 4 and 5 on the reference in synchronization with the index signal, reproduced by the rad 10° 12 on the magnetic head to be adjusted, and the reproduced signal is used as the index signal. Adjustments can be made by performing 1 to 1 recalibration and observing with the A cilloscope 21.

According to the present invention as described in detail, it is possible to adjust the upper and lower adjusted magnetic heads, that is, the double-sided head, without using a CF disk, and the adjustment cost can be extremely reduced. .

[Brief explanation of the drawing]

FIG. 1 shows a magnetic helad i1'J in an embodiment of the present invention.
FIG. 2 is a block diagram of an electric circuit for the magnetic head adjustment device, and FIGS. 3 J3 and 4 are waveforms showing examples of recording signals and reproduction signals of the magnetic head adjustment device. It is a diagram. DESCRIPTION OF SYMBOLS 1... Magnetic recording medium, 4... Lower reference head, 5...
... Upper reference head, 10... Lower magnetic head to be adjusted, 12... Upper magnetic head to be adjusted, 17... Recording circuit, 20a. 20b... Regeneration circuit agent Yoshihiro Morimoto Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1.1j A rotational drive means for rotating the recording medium at a predetermined speed, and at least one pair of reference heads facing each other vertically;
A recording means for recording a predetermined signal on both sides of the magnetic recording medium by the reference head, and a reproducing means for reproducing and amplifying the signals from a pair of vertically opposed magnetic heads to be adjusted, the recording means and the reference head A magnetic head adjusting device configured to record a predetermined signal on the magnetic recording medium, reproduce it by the adjusted magnetic head and reproducing means, and adjust the adjusted magnetic head so that the reproduced signal has a predetermined output. 2. The magnetic head adjusting device according to claim 1, wherein the reference head is configured to be movable by a predetermined amount in the radial direction and tangential direction with respect to the rotation center of the magnetic recording medium.