JPH0138738Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a magnetic head position adjustment device for a tape deck or the like.

BACKGROUND ART As shown in FIG. 1, a magnetic head position adjusting device has a magnetic head 1 that is movable in a direction perpendicular to the running direction of a magnetic tape 2.
tracking error of the magnetic head 1 is detected, the motor 3 is rotated according to the detected error, and the rotational motion is converted into a linear motion by the pinion 4 and the rack 5 and applied to the reproducing head 1, thereby adjusting the tracking of the magnetic head 1. There is a device that does this. Further, as shown in FIG. 2, the magnetic head 6 is made rotatable with the gap part of the magnetic head 6 in contact with the magnetic tape 7, and an azimuth error of the magnetic head 6 is detected. There is a device that adjusts the azimuth angle of the magnetic head 6 by rotating the magnetic head and applying the rotation to the magnetic head 6 via gears 9 and 10.

In this way, conventionally, the tracking position adjustment and azimuth angle adjustment of the magnetic head have been performed individually by each drive mechanism, but it is now possible to simultaneously perform the tracking position adjustment and azimuth angle adjustment of the reproducing head with a single drive mechanism. This was difficult because the drive mechanism had to be extremely complicated.

SUMMARY OF THE INVENTION The object of the present invention is to provide a magnetic head position adjusting device that can simultaneously adjust the tracking position and azimuth angle of the magnetic head using a single and simple drive mechanism.

The magnetic head position adjustment device of the present invention includes a pair of actuators that support symmetrical positions around an axis perpendicular to the gap plane of the magnetic head, and detects tracking errors of the magnetic head and outputs them as tracking error signals. tracking error detection means for detecting the azimuth error of the magnetic head and outputting it as a first azimuth error signal; and adding the tracking error signal and the first azimuth error signal to generate a first error signal. and a second addition means that adds a tracking error signal and a second azimuth error signal having an opposite phase to the first azimuth error signal to obtain a second error signal. The present invention is characterized in that one of the actuators moves the supporting position of the magnetic head substantially in the tracking adjustment direction in response to a first error signal, and the other actuator responds to a second error signal.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 3 to 6.

FIG. 3 shows the drive mechanism of the magnetic head position adjusting device according to the present invention. In this figure, a magnetic head 11 has a plurality of reproduction channels, and a support member 11 is connected to a magnetic head 11 via bimorphs 12 and 13.
It is supported by 4. The bimorphs 12 and 13 have a long flat plate shape, and when a voltage is applied between the planes, they bend depending on the voltage level and change the direction of the bending depending on the polarity of the applied voltage. magnetic tape 15
If the direction perpendicular to the running direction of the magnetic tape 15 is defined as the vertical direction, one end of the bimorph 12 is fixed to the top of one of the two sides of the magnetic head 11 that are substantially perpendicular to the running direction of the magnetic tape 15. One end is fixed to the lower part of the other of the two sides of the magnetic head. The other ends of the bimorphs 12 and 13 are fixed to a support member 14.

FIG. 4 shows a control circuit for the magnetic head position adjusting device according to the present invention. In this figure,
The reproducing head 11 is a reproducing head element 1 that divides one predetermined track 15a of the magnetic tape 15 into two and reads out recorded contents at the same position in the tape running direction.
1a and 11b. Reproduction head element 11
A differential amplifier 16 is connected to the output terminals of the reproducing head elements 11a and 11b, and the difference in the output level of the reproducing head elements 11a and 11b is obtained. The output terminal of the differential amplifier 16 is
It is connected to one input end of adders 19 and 20 via an LPF (low pass filter) 17 and a phase compensation circuit 18. Differential amplifier 16, LPF1
7 and the phase compensation circuit 18 form a tracking error detection circuit. Also, the reproduction head element 11
A comparator 21 is connected to the read head element 11a, a comparator 22 is connected to the read head element 11b, and the read head element 11a,
The output signal waveform of 11b is converted into a square waveform.
The output terminal of the comparator 21 is connected to the positive input terminal of the differential amplifier 24 via the integrating circuit 23, and the output terminal of the comparator 22 is connected to the negative input terminal of the differential amplifier 24 via the integrating circuit 25. The difference level between the output signals 23 and 25 is obtained. The output terminal of the differential amplifier 24 is connected to one input terminal of the multiplier 26, and the output terminal of the differential amplifier 24 is connected to one input terminal of the multiplier 26.
The output level of the differential amplifier 24 and the output level of the comparator 21 are multiplied together. The output terminal of the multiplier 26 is connected to the phase compensation circuit 28 via the LPF 27, and the output terminal of the phase compensation circuit 28 is connected to the other input terminal of the adder 19 and the other input terminal of the adder 20 via the inverter 29. connected to the input end of the Comparators 21 and 22, integration circuits 23 and 25, differential amplifier 24, multiplier 26, LPF 27 and phase compensation circuit 28 form an azimuth error detection circuit. Bimorph 12 is connected to the output terminal of adder 19.
A drive circuit 30 for the bimorph 13 is connected to the adder 20, and a drive circuit 31 for the bimorph 13 is connected to the output terminal of the adder 20.

In the magnetic head position adjusting device according to the present invention having such a configuration, the difference in signal level output from the reproduction head elements 11a and 11b during the reproduction mode of the tape deck is detected by the differential amplifier 16.
As the tracking position by the magnetic head 11 becomes more inaccurate, a level difference occurs between the signals output from the reproducing head elements 11a and 11b. Since the level difference signal is supplied to the LPF 17, only the low frequency component of the level difference signal is phase compensated by the phase compensation circuit 18. The output signal of the phase compensation circuit 18 is supplied to adders 19 and 20 as a tracking error signal.

Further, the signals outputted from the reproduction head elements 11a and 11b are converted into square wave signals by comparators 21 and 22, respectively, and integrated circuits 23 and 25.
It is integrated by. Now, the reproduction head element 11a
Assuming that the signal output from the reproducing head element 11b has a phase lead than the signal output from the reproducing head element 11b,
The square wave signal output from the comparator 21 is shown in Fig. 5a.
The square wave signal output from the comparator 22 is as shown in FIG. 5b. Since the integrating circuits 23 and 25 integrate the square waveform signal, it becomes a triangular wave signal, and the solid line in FIG. 5c is the output signal of the integrating circuit 23.
The broken line in FIG. 5c is the output signal of the integrating circuit 25. The level difference between the triangular wave signals output from the integrating circuits 23 and 25 is taken by the differential amplifier 24,
The output signal of the differential amplifier 24 is as shown in FIG. 5d. The multiplier 26 multiplies the output signal of the differential amplifier 24 and the output signal of the comparator 21 to obtain a multiplied signal as shown in FIG. 5e. This multiplied signal is
Only the low-frequency components of the multiplied signal are supplied to the LPF 27, as shown in FIG.
8. The output signal of the phase compensation circuit 28 is supplied to the adder 19 as a first azimuth error signal, and the inverted signal of the first azimuth error signal by the inverter 29 is supplied to the adder 20 as a second azimuth error signal.

The signal output from the adder 19 is the level sum of the tracking error signal and the first azimuth error signal, and is supplied to the drive circuit 30 as the first error signal. Similarly, the signal output from the adder 20 is the level sum of the tracking error signal, the second azimuth error signal, and the second azimuth error signal, and is supplied to the drive circuit 31 as the second error signal. The drive circuits 30 and 31 apply a voltage according to the first or second error signal level to the bimorph 12,
13.

When there is only a tracking error in the magnetic head 11, the bimorphs 12 and 13 are bent by the same amount in the same direction as shown in FIG. The magnetic head 11 moves in parallel in the perpendicular direction (arrow A). On the other hand, in the case of only an azimuth error, the magnetic head 1 is deflected by the same amount in opposite directions as shown in FIG.
1 rotates in the direction of arrow B. Therefore, when a tracking error and an azimuth error occur together, the applied voltage levels to the bimorphs 12 and 13 are different from each other, so the amount of deflection of the bimorphs 12 and 13 is different from each other, and the magnetic head 11 is It moves in a direction perpendicular to the running direction of the magnetic tape at the contact surface with the magnetic tape, and rotates about an axis perpendicular to the contact surface as the rotation axis.

In the above-described embodiment of the present invention, a bimorph is used as the actuator of the magnetic head, but the present invention is not limited to this, and the magnetic head may be driven using a coil and a magnet. For example, as shown in FIG. 7, arm members 41 and 42 are provided parallel to each other at symmetrical positions with respect to an axis perpendicular to the gap surface of the magnetic head 11, and coils 43 and 44 are provided at the tips of the arm members 41 and 42. is formed. Magnets 45 and 4 are located near the coils 43 and 44.
6 are each fixed, and a magnetic circuit is formed in each. A rotary shaft 47 projects from the opposite surface of the magnetic head 11 from the gap surface, and the rotary shaft 47 is rotatably supported by a bearing 48 so that the magnetic head 11 can rotate in the direction of arrow C. The bearing 48 also has a leaf spring 50 on the support base 49.
51, so that the magnetic head 11 can move in a direction perpendicular to the running direction of the magnetic tape (arrow D). in this case,
This has the advantage that the drive mechanism operates at a lower voltage than when using a bimorph.

Effects As described above, according to the magnetic head position adjustment device of the present invention, it is possible to simultaneously adjust the tracking position and azimuth angle of the magnetic head with a simple drive mechanism, making it possible to form multiple tracks on a single magnetic tape. It is possible to suppress output fluctuations due to waving of the magnetic tape in tape decks where the track width becomes small, and in tape decks that record and play back very high frequency signals, azimuth deviation has a large negative impact on the playback output level. However, this can be prevented. Therefore, the present invention is suitable for use in digital audio tape recorders that have a small track width and a high recording signal frequency, and can solve various problems such as the accuracy of the cassette half, the accuracy of the running system, or compatibility with other tape decks. It can be fully resolved.

[Brief explanation of the drawing]

1 and 2 are diagrams showing a drive mechanism of a conventional magnetic head position adjustment device, FIG. 3 is a plan view showing a drive mechanism of a magnetic head position adjustment device according to the present invention, and FIG. 4 is a diagram showing a drive mechanism of a magnetic head position adjustment device according to the present invention. 5 is a waveform diagram showing the operation of each part of the control circuit of FIG. 4, FIG. 6 is a plan view showing the operation of the drive mechanism of FIG. 3, and FIG. 7 is a block diagram showing the control circuit of the head position adjustment device. The figure is a perspective view showing a drive mechanism in another embodiment of the present invention. Explanation of symbols of main parts: 1, 6, 11...magnetic head, 2, 7, 15...magnetic tape, 3, 8...
...Motor, 12,13...Bimorph, 14...
Support member.

Claims (1)

[Scope of utility model registration request] a pair of actuators that support symmetrical positions about an axis perpendicular to the gap plane of the magnetic head; a tracking error detection means that detects a tracking error of the magnetic head and outputs it as a tracking error signal; azimuth error detection means for detecting an azimuth error of the magnetic head and outputting it as a first azimuth error signal; and first addition means for adding the tracking error signal and the first azimuth error signal to produce a first error signal. and a second adding means for adding a second azimuth error signal having an opposite phase to the first azimuth error signal and the tracking error signal to obtain a second error signal, A magnetic head position adjusting device, wherein one actuator moves the supporting position of the magnetic head substantially in the tracking adjustment direction in response to the first error signal and the other actuator responds to the second error signal.