JPS60133519A - Adjusting device of magnetic head - Google Patents

Abstract

PURPOSE:To attain highly accurate adjustment of the height and azimuth angle of a magnetic head on a cylinder in rotating by rotating a height adjusting screw and an azimuth adjusting screw in the rotary cylinder by slight displacement generated from an electromechanical transducer. CONSTITUTION:Electricity is sent to a motor 20 by a fixed brush 18 through a slipping 19, the rotation of the motor 20 fixed on the rotary cylinder 9 is decelerated by a worm gear 27 and a reduction gear 28 and a gear 30 fixed on the same axis as the gear 28 is rotated together with the gear 28. Adjusting gears 31 are rotated in accordance with the rotation of the gear 30 and the leading end parts 33, which have hexagonal sections, of adjusting shafts 32, the main shaft of the gears 31, are fitted to hexagonal holes of the height adjusting screw 10 and the azimuth adjusting screw 11 to rotate the screws 10, 11. Consequently, the height and azimuth angle of the magnetic head 3 on the cylinder 9 in rotating can be adjusted highly accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for adjusting the height and azimuth angle of a magnetic head in a helical magnetic recording/reproducing device having a rotating cylinder.

The structure of the conventional example and its problems First, height adjustment of the magnetic head will be described with reference to FIG. In FIG. 1, when the gap between the recording pattern 1 and the reproduction to 2 does not match in the gap line direction A, a deterioration of the reproduction output known as a non-tracking loss occurs.

Next, the azimuth loss will be described using FIG. In FIG. 2, the gap line direction A of recording pattern 1 is
If the gap line direction B of the reproduction head 2 is not parallel to the gap line direction B of the reproduction head 2, deterioration of the reproduction output known as azimuth loss occurs, and the angle formed by the gap line direction A of the recording pattern 1 and the gap line direction B of the reproduction head 2 occurs. If n is 0, the trunk width is W, and the recording wavelength is λ, then the azimuth loss is as follows. Therefore, the azimuth loss increases as the angle θ between the gap line direction A of the recording pattern 1 and the gap line direction B of the magnetic reproducing radar 2 and the track width W increase, and as the recording wavelength λ decreases? show.

For example, when self-recording and reproducing (reproducing with the same device that recorded) with a magnetic head that can perform both recording and reproduction, the height of the magnetic recording head, the azimuth angle and the height of the magnetic reproducing head,
and azimuth angle are the same, no track deviation loss or azimuth loss occurs. However, when the magnetic recording head and the magnetic reproducing head are separate, or when recording and reproducing are performed using different devices, the difference in height and azimuth angle of each magnetic head during recording and reproducing causes Track misalignment losses and azimuth losses occur. In order to prevent this, the height and azimuth angle of the magnetic heads must be made the same.

Here, a description will be given of a magnetic helad base (hereinafter referred to as a head base) in which the height and azimuth angle of a magnetic head in a helical video tape recorder having a rotating cylinder can be adjusted.

The following HeradoPace is disclosed in Japanese Patent Application No. 56-29172. FIG. 3 shows the shape of the helad base, and FIG. 4 shows the helad base attached to a rotating cylinder. Figures 3a and 3b are a front view and a side view, respectively. In the figure, 3 is a magnetic head, 4 is a magnetic head base, and 5 is a cylinder mounting screw hole. In particular, in the head base 4, 6 is named an arm part and 7 is named a head part.

Figures 4a and 4b are a plan view and a sectional view of the machine.

In the same figure, 8 is a screw that fits into the cylinder, 9 is a rotating cylinder, C is a reference surface of the rotating cylinder, 1° is a height adjustment screw of the magnetic head that contacts the lower surface of the head, and 11 is a screw that is attached to the lower surface of the arm part 6. This is the azimuth adjustment screw that comes into contact. D is a contact point between the lower surface of the head section and the height adjustment screw 1o, and E is a contact point between the lower surface of the arm section 6 and the azimuth adjustment screw 11. Now, by using the height adjusting screw 1O, the head portion 7 moves in the direction of the arrow F shown in FIG. Also, azimuth adjustment screw 11
As a result, the arm portion 6 moves in the direction of the arrow G shown in FIG. 4, and the same effect is exerted on the head portion 7. The movement of the head section 7 is considered to be the movement of the magnetic head 3. In this way, both height adjustment screws 10 and azimuth adjustment screws 11
This allows for finer adjustments.

Here, a conventional height and azimuth angle adjusting device for a magnetic head will be explained. Figures 6a and b are plan views;
FIG. In the figure, the perpendicular direction is designated as H. Further, the magnetic head 3 is located on a helad base, and the head base 4 is attached to a rotating cylinder e with cylinder attachment screws 8.

The rotary cylinder 9 is mounted on the fixed base 12 using the knob 12a.
It is fixed at b. The reference surface C of the rotating cylinder shown in FIGS. 4a and 4b is in close contact with the reference surface 13 of the fixed base 12b. In this state, the height and azimuth angle of the magnetic head 3 are measured using the microscope 14, and the height and azimuth angle of the magnetic head 3 are adjusted. FIG. 6 is an enlarged view of the magnetic head 3 seen from the front of the microscope 14. The height of the magnetic head 3 is adjusted using a microscope 14 using a height adjusting screw 1o so that the lower end 16 of the gap 16 is at a predetermined height. Even if the height of the magnetic head 3 needs to be accurate to 1 micron,
The height of the magnetic head 3 can be adjusted using a high-magnification microscope. Next, adjustment of the azimuth angle of the magnetic head 3 will be explained. The azimuth angle is the vertical direction H in Figure 6.
This is the angle θ between the gap line direction A and the gap line direction A. A straight line extending the gap lower end 16 in the vertical direction and the gap upper end 17
When the distance between is I, the azimuth angle is expressed by the following formula.

θ=S I N −'(I/'W) where 0
is 6 minutes, Wi1oo micron and n, I is o, 1rs
Becomes a micron. If using a high magnification microscope, n is 0.1
Although 6 microns is measurable, it is difficult to observe the gap 16 within the same field of view. Same as gap 16
If observation is not possible within the field of view, move the microscope 14 in the perpendicular direction B.
However, the rotating cylinder 9 is moved in the perpendicular direction B iIJ
There is a need to. However, even in the case of the above mentioned 0.1
Moving at 6 microns is very difficult. Therefore, in the above-mentioned apparatus, it is difficult to measure the azimuth angle with high precision, and it is also very difficult to adjust the azimuth angle with high precision.

As shown in the above explanation, although it was possible to adjust the height with conventional magnetic head height and azimuth angle adjustment devices, highly accurate adjustment of the azimuth angle was extremely difficult. Ta.

Purpose of the Invention The present invention aims to reproduce an LrLm master tape recorded with ideal high precision using a magnetic head on a rotating cylinder that should be adjusted, while adjusting the height and azimuth of the magnetic head so that the reproduction output is maximized. An object of the present invention is to provide a magnetic head adjustment device that can adjust the height and azimuth angle of a magnetic head with the same accuracy as a master tape by adjusting the angle.

Structure of the Invention The present invention is based on the present invention, when a magnetic head on a rotating cylinder is reproducing a master tape recorded with ideal high precision, the magnetic head is arranged on the rotating cylinder in a rotating state and the cylindrical size and azimuth of the magnetic head are reproduced. This is for angle adjustment.

Therefore, the present invention provides an electro-mechanical transducer and the above-mentioned
It has a slip ring and brushes that supply electricity to the mechanical transducer. In addition, the electro-mechanical transducer needs to perform step motion with minute displacement, and depending on the type of electro-mechanical transducer,
There are cases where a movement amount detector for detecting the amount of movement of the mechanical transducer and a control circuit that receives a signal from the movement amount detector and controls the electro-mechanical transducer are required. Next, the slight displacement of the stethoscope movement generated by the electro-mechanical transducer becomes a movement by the transmission device that rotates the height adjusting screw and the azimuth angle adjusting screw in the rotary cylinder. By rotating the height adjusting screw and the azimuth angle adjusting screw, the height and azimuth angle of the magnetic head can be adjusted.

Description of examples Next, the implementation of the present invention will be fully explained. Figure 7a.

bH The figure a shows the overall configuration of the magnetic head and the height and azimuth angle adjusting device according to the present invention mounted on the rotary cylinder. It is a sectional view seen from one direction. In the figure, electricity is supplied to an electric motor 2o via a slip ring 19 by a brush 18 fixed and removed from the outside. The electric motor 2o is attached to a substrate plate 22 with screws 21. The substrate plate 22 is attached to the rotating cylinder 9 by screws 23, and rotates together with the rotating cylinder 9. An encoder 24 is provided coaxially with the electric motor 2o, and the rotation angle of the encoder 24 is detected by a light emitting diode 25 and a phototransistor 26. There is also a worm gear 2 on the same axis of the electric motor 2°.
There are 7. The rotation of the worm gear 27 is transmitted to the reduction gear 28. The rotation of the electric motor 20 is decelerated by the worm gear 2T and the reduction gear 28. The reduction gear 28 is fixed to the intermediate shaft 29. As the reduction gear 28 rotates, the intermediate gear 3o fixed coaxially rotates. The adjustment gear 31 rotates as the intermediate gear 30 rotates. The adjustment shaft 32, which is the main shaft of the adjustment gear 31, has a tip 33 having a hexagonal cross section. The height adjustment screw 10 and azimuth angle adjustment screw 11 of the magnetic head 3 are hexagon socket screws,
, are connected at the tip 33, and rotate with the rotation of the tip 33. As shown above, the rotation of the electric motor 2o is transmitted and decelerated by several gears, and the height adjustment screw 1
o and the rotation of the azimuth angle adjustment screw 11. Further, in FIG. 7a, the electric motor 2o, the detector, and the gears are arranged to rotate the height adjusting screw 1Q of the magnetic head and the azimuth angle adjusting screw 11, respectively.

Further, in order to support the main shaft of the gear, there is an upper grate 34, and the upper plate 34 is supported by a support member 35. Between the top plate 34 and the base plate 22 is the reduction gear 28 shown above. Intermediate gear 30. There is an adjustment gear 31.

Although it has been shown above that the rotation of the electric motor 20 is linked to the rotation of the height adjustment screw 10 and the azimuth angle adjustment screw 110, the overall wiring will be shown below.

FIG. 8 shows the entire wiring diagram. Rotating cylinder 9
is fixed to the disc 37 with the disc mounting screw 36.
ing. The rotating cylinder 9 rotates as the disk 37 rotates. A magnetic head 3 housed in a rotating cylinder 9 reproduces a mask tape 38. The master tape 38 is a tape recorded with the ideal cylindrical size and azimuth angle of the magnetic head. master tape 38
runs along the guide portion 4o of the fixed cylinder 39.

The reproduced output signal from the magnetic head 3 is connected to the head lead wire 41.
This leads to the entire inside of the disk 37 and to the rotating transformer 42 on the rotating side. The rotation transformer 42 on the rotating side is attached to the disk 3γ and rotates together with the disk 37. The reproduction output signal is transmitted from the rotary side rotary transformer 42 to the stationary side rotary transformer 43.

As is well known, signal transmission from the rotary side rotary transformer 42 to the stationary side rotary transformer 43 is performed in a non-contact manner. The output signal from the stationary rotary transformer 43 becomes an input to a regenerative amplification circuit 44 and is amplified. Next, one end of the electric motor 20, the light emitting diode 26, and the phototransistor 26 are connected to the rotating cylinder 9, and one end of each is connected to an external circuit via a slip ring 19 and a brush 18. The external ground is also connected to the rotary cylinder 9 via a slip ring 19 and a plank 18.

Since the height adjustment and azimuth angle adjustment of the magnetic head 3 is performed by extremely delicate rotation of the height adjustment screw 1Q and the azimuth angle adjustment screw 11, the electric motor 20 is required to perform step motion with delicate displacement. .

Therefore, it is necessary to detect and control the rotation angle of the electric motor 20 to prevent the electric motor 2o from running out of control.

In order to detect the rotation angle of the electric motor 2○, a light emitting diode 25 and a light emitting circuit 44 connected to the light emitting diode 25 cause the light emitting diode 25 to emit light, and an encoder 24 and an encoder 24 converting the light emitted from the light emitting diode 26 into all pulses. It has a phototransistor 26 that converts the converted pulsed light into electricity, and a light receiving circuit 45 connected to the phototransistor 26. The output of the light receiving circuit 45 is a pulse-like waveform generated according to the rotation angle of the electric motor 20. The output of the light receiving circuit 45 becomes an input to a control circuit 46 that controls the electric motor 20. The control circuit 46 controls the delicate rotation of the motor 20 while detecting the output of the light receiving circuit 45, that is, the rotation angle of the motor 200. As shown above, the electric motor 20 includes a slip ring 19 and brushes 18.
The entire system is controlled by an external control circuit 26. Also,
Since the rotation of the electric motor 20 is linked to the rotation of the height adjustment screw 1o and the azimuth angle adjustment screw 11 of the magnetic head 3,
To the control circuit 26! The height and azimuth angle of the magnetic nose 3 are also controlled on the rotating rotating cylinder.

The height and azimuth angle of the magnetic head 3 on the rotating cylinder being rotated are controlled by the control circuit 26, and the reproduction output signal from the magnetic head 3 of the master tape 38 is transmitted to the reproduction amplification circuit 44. has been done.

The adjustment process using the above magnetic head height and azimuth angle adjustment device will be described below.

Figure 9a shows the height of the magnetic head and the azimuth angle ['(r
Figure C shows the state before the height adjustment of the magnetic head has been performed, Figure C shows the state after the height and azimuth angle adjustment of the magnetic head has been completed, and Figures d, e, and f show the state in which the height and azimuth angle adjustment of the magnetic head has been completed. Diagram a, b
, c, the envelope of the reproduced output signal in each case? show. In d, e, and f of the figure, the horizontal axis is time, and the vertical axis is output level. First, in Figure a, the state is before the height and azimuth angle adjustment of the magnetic head, so the track deviation n
The output level of the reproduced output signal is small due to loss and azimuth loss. Next, in the same figure, the height adjustment screw 10 is rotated to adjust the height of the magnetic throat 3, and the reproduced output signal is maximized. In the case shown in the figure, there is no track deviation loss, and the output level of the playback output signal is as shown in the figure a.
Although this is larger than in the case of , azimuth loss occurs.

Finally, in Figure C, the azimuth angle adjustment screw 11 is rotated to adjust the azimuth angle of the magnetic nozzle 3, and the reproduced output signal is maximized. In the case of C in the same figure, there is no track n
There is no loss or azimuth loss, and the output level of the reproduced output signal increases to an ideal state.

The present invention is not limited to the one embodiment described above, and various modifications are possible. For example, although the above embodiment uses an electric motor and requires a rotation angle detector for the electric motor to obtain delicate rotation, another electro-mechanical transducer may be used.

For example, if a Stenching motor or piezoelectric ceramic is used, a subtle movement can be easily obtained, so a detector to detect the amount of movement is not necessary. Further, although in the above embodiments gears are used to transmit the motion of the electromechanical transducer to the height and azimuth adjustment screws of the total magnetic head, other transmission devices may be used. for example,
It may be a belt transmission, a friction wheel transmission, a link transmission or another transmission. Furthermore, any of the above transmission devices may be combined.

Effects of the Invention As described above, the present invention makes it possible to adjust the height and azimuth angle of the magnetic head while the magnetic head on the rotating cylinder is reproducing a master tape, thereby achieving the ideal This has the effect of providing magnetic head height and azimuth angle precision equivalent to that of a master tape produced with high precision.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram for explaining track misalignment loss, Fig. 2 is an explanatory diagram for explaining azimuth loss, Fig. 3 a and b are front and side views showing the magnetic helad base, Fig. 4 a, b
are a plan view and a sectional view showing the state in which the magnetic head base in FIGS. 3a and 3b is attached to a rotating cylinder, and FIGS.
FIG. 6 is an enlarged view of the magnetic head in FIG. 6, FIG. 7 is an embodiment of the present invention. A plan view and a sectional view showing the overall configuration of the magnetic head adjustment device in the example, FIG. 8 is a wiring diagram showing the entire wiring in the example, and FIGS. 9 a to f are explanations showing the adjustment process in the example. It is a diagram. 3... Magnetic head, 4... Magnetic head base, 9... Rotating cylinder, 18...
・Brush, 19...Slip ring, 2O...
····Electric motor. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 M4fl! Figure 3 1b M4fl! it '- Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] an electro-mechanical transducer mounted on a rotating cylinder and rotating together with the rotating cylinder; a slip ring and a brush for externally supplying electricity to the electro-mechanical transducer; A control circuit for controlling the user externally, a transmission device that receives the movement of the electro-mechanical transducer as input, and a height adjustment screw and an azimuth angle adjustment screw for a magnetic head that rotates by the output movement of the transmission device. A magnetic head adjustment device.