JPH04283410A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve the linearity of a track at the time of recording by storing the displacement amounts of a magnetic head in a memory and operating a feedback control so that the displacement amounts of the magnetic head can be equal to the displacement amounts recorded in the memory at the time of recording. CONSTITUTION:A signal on a reference tape 50 is regenerated, by a magnetic head 1, amplified by an amplifier 5, a tracking error signal is generated by a tracking error detecting circuit 6 and inputted to an adder 11. The output of the adder 11 rocks the magnetic head 1 so that an electromechanical transducing element 2 can follow up the curve of the track. Simultaneously the displacement pattern of the element 2 based on the output of a position sensor 4 is recorded in a memory 16. Then, the recorded signal is recorded on a magnetic recording medium. Also, at the time of the reproduction of the tape 50, the displacement pattern data of the element 2 recorded in the memory 16 is inputted to a differential amplifier 14, the feedback of a difference to it and the output signal of the sensor 4 to the element is operated, so that the displacement amounts of the element 2 and the head 1 can be equal to the displacement amounts recorded in the memory 16.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention is applicable to video tape recorders, digital audio tape recorders, etc.
The present invention relates to a magnetic recording/reproducing device equipped with a rotating head assembly.

0002

2. Description of the Related Art In recent years, in order to record large amounts of information on magnetic recording media, methods have been used to reduce the width of recording tracks and increase the recording capacity. In this method, it is difficult to ensure compatible reproduction because the track width becomes small, and conventionally a servo method has been used in which a magnetic head follows a recording track using a movable head structure.

FIG. 7 shows the configuration of a conventional magnetic recording/reproducing apparatus disclosed in, for example, Japanese Patent Application Laid-Open No. 1-10514, and is particularly concerned with track bending before and after electronic editing. In the figure, 1 is a magnetic head for recording and reproducing signals on a magnetic recording medium, and 2 is an electromechanical transducer consisting of a piezoelectric element with magnetic head 1 mounted on its tip. Can swing in vertical direction. 3 is an electrode of the electromechanical transducer 2; 4 is a position sensor that is provided on the electromechanical transducer 2 and can detect distortion according to its displacement as an electrical signal; 5 is a reproducing amplifier that amplifies the output of the magnetic head 1; 6 is a tracking error detection circuit that detects a tracking error from the output of the reproduction amplifier 5, and as shown in FIG.
5, a selector 36 for selecting the output from the oscillator 35, filters 37, 38, diodes 39, 40, a differential amplifier 41, and an output terminal 42.

8 is an A/D converter that converts the signal detected by the tracking error detection circuit 6 into digital data; 9 is a memory that stores the digital data converted by the A/D converter 8; and 10 is a digital memory of the memory 9. A D/A converter that converts data into an analog signal, 11 an adder, 12 a driver connected to the electrode 3,
13 is a sensor amplifier that amplifies the output of the position sensor 4;
4 is a differential amplifier whose one input terminal is connected to the sensor amplifier 13; 15 is an A/D converter that converts the output of the differential amplifier 14 into digital data; and 16 is a memory for storing digital data from the A/D converter 15. A memory 17 is a D/A converter that converts the digital data in the memory 16 into an analog signal, and is connected to the other input terminal of the differential amplifier 14.

A switch 18 turns on/off the connection between the adder 11 and the differential amplifier 14, a recording amplifier 20 supplies signals to the magnetic head 1 during recording, and a switch 19 connects the magnetic head 1 to the playback amplifier 5. Can be switched.

[0006] In the above configuration, an example will be described in which the problem of image distortion at an editing point due to mismatch in curvature between a previously recorded track and a newly recorded track during electronic editing is solved. During electronic editing (insert editing), first turn off the switch 18 and set the switch 19 to the terminal 19a.
The magnetic recording medium is connected to the side, and the playback operation starts from the front of the joint of the magnetic recording medium. During this operation, the bending state of the track is measured, the magnetic head 1 is made to follow the track, and the displacement data of the magnetic head 1, that is, the output of the position sensor 4, is stored in the memory 16. Next, the recording state is switched to a location where the recording medium becomes a seam. That is, the switch 18 is turned on, the switch 19 is connected to the terminal 19b side, and the magnetic head 1 is controlled in a closed loop based on the data in the memory 16 so that the track curve is the same as the track curve before the joint.

[0007]

[Problem to be solved by the invention] In the conventional device,
As mentioned above, emphasis is placed on the reproduction aspect of how to make the magnetic head 1 follow a magnetic tape with track curvature, and the linearity of recorded tracks depends on the precision of the tape running guide member and the rotating cylinder. I remained dependent. Therefore, depending on the amount of curvature of the recorded track, compatible playback often cannot be ensured.

The present invention has been made to solve the above-mentioned problems, and aims to provide a magnetic recording and reproducing device that improves the linearity of tracks during recording and facilitates compatible reproduction. .

[0009]

[Means for Solving the Problems] A magnetic recording/reproducing device according to the present invention causes a magnetic head to follow a reference tape having a recording track with good linearity in advance, and detects the amount of displacement of the magnetic head at this time using a position sensor. and means for performing feedback control so that the amount of displacement of the magnetic head during recording matches the amount of displacement stored in the memory.

0010

In the present invention, a reference tape having a recording track with good linearity is followed in advance by a magnetic head, and the amount of displacement of the magnetic head at this time is stored in a memory. or,
The amount of displacement of the magnetic head during recording is controlled so as to match the amount of displacement stored in the memory.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a magnetic recording and reproducing apparatus according to this embodiment, in which 1 is a magnetic head for recording and reproducing signals on a magnetic recording medium, and 2 is an electromechanical transducer consisting of a piezoelectric element having the magnetic head 1 mounted on its tip. The magnetic head 1 can be oscillated in a direction perpendicular to the scanning direction depending on the voltage. To explain this situation with reference to FIG. 5, the electromechanical transducer 2 is composed of two layers of piezoelectric elements, and when a voltage is applied in a certain direction as shown in FIG. As a result, the other layer 2b receives a compressive force and deforms in the direction of arrow A, as shown in FIG. Also, if a voltage is applied in the opposite direction to that shown above, it will deform in the opposite direction to that shown in Figure (B).
The magnetic head 1 can be oscillated depending on the direction and magnitude of the voltage.

Reference numeral 3 denotes an electrode of the electromechanical transducer 2, and 4 is a position sensor provided on the electromechanical transducer 2, which detects strain corresponding to the displacement as an electric signal and detects the position of the magnetic head 1. , specifically, as shown in FIG.
Due to the rocking, the position sensor 4 receives a tensile and compressive force, and the electrical resistance value changes. 5 is a reproducing amplifier that amplifies the output of the magnetic head 1, and 6 is a tracking error detection circuit that detects a tracking error from the output of the reproducing amplifier 5, the configuration of which is shown in FIG.

11 is an adder, 12 is a driver connected to the electrode 3, 13 is a sensor amplifier that amplifies the output of the position sensor 4, 14 is a differential amplifier whose one input terminal is connected to the sensor amplifier 13, and 15 16 is an A/D converter that converts the output of the differential amplifier 14 into digital data;
17 is a D/A converter that converts the digital data of the memory 16 into an analog signal, and the differential amplifier 14
is connected to the other input terminal of the 18 is a switch that turns on/off the connection between the adder 11 and the differential amplifier 14; 20 is a recording amplifier that supplies a signal to the magnetic head 1 during recording; and a switch 19 switches the connection to the magnetic head 1 to the reproduction amplifier 5. . 50 is a reference tape with good linearity of recorded tracks (linearity is 1 to 2 μm)
).

Next, the operation of the configuration shown in FIG. 1 will be explained. Before the reference tape 50 is played back, no data is stored in the memory 16, and after the reference tape 50 is played back, the data is stored. First, to explain this behavior,
Switch 18 is turned off and switch 19 is turned off to terminal 19.
When connected to the a side, the signal on the reference tape 50 is reproduced by the magnetic head 5, amplified by the reproduction amplifier 5, and the tracking error detection circuit 6 extracts tracking data from the signal and generates a tracking error signal. The signal is input to the adder 11.

The output of the adder 11 is sent to the electromechanical transducer 2 via the driver 12, and the element 2 swings the magnetic head 1 so as to follow the curve of the track. At the same time, the output of the position sensor 4 is amplified by the sensor amplifier 13, sent through the differential amplifier 14 to the A/D converter 15, and converted into digital data. This digital data is transferred to the memory 16, and the displacement pattern of the electromechanical transducer 2 based on the output of the position sensor 4 is stored in the memory 16. During this operation, D/A converter 1
7 does not operate, and only the output of the sensor amplifier 13 is input to the differential amplifier 14.

To explain in detail the method of generating (detecting) the tracking error signal in the above operation, as shown in FIG. 2, a pilot signal is recorded on the reference tape 50 in a form superimposed on the video signal in order to obtain the tracking error signal. has been done. These signals are of four types with different frequencies from f1 to f4. For example, as shown in FIG. 3, when a track in which f2 is recorded is reproduced by a magnetic head 1 having a track width larger than that of the track, as shown in FIG. In addition to reproducing f2, it also plays f1 and f3 on both sides.
Also plays.

As shown in FIG. 4, the signal on the reference tape 50 is regenerated by the magnetic head 1, amplified by the reproduction amplifier 5, and then input to the tracking error detection circuit 6. Here, the video signal is removed by the filter 33 and pilot signals f1, f3, f2 are extracted. Further, the selector 36 generates a pilot signal f2 from the oscillator 35, and this signal and the signals f1 to f3
is multiplied by the multiplier 34 and is called a beat (
A signal having two frequencies, f3 - f2 ) and (f2 - f1 ), is obtained. Furthermore, this signal is filtered by filter 3.
7 and 38, their levels are compared by a differential amplifier 41, and the difference is outputted from an output terminal 42 as a tracking error signal. This method is called the four-frequency pilot signal tracking method, and is generally f
1 = 102.5Hz, f2 = 118.9Hz, f3
=165.2Hz and f4 =148.7Hz are used.

When the magnetic head 1 traces the track center of f2 in FIG. 3, the reproduction output level of f1 and f3 is the same, so this tracking error signal is divided into (f3 - f2) and (f2 - The beat level of f1) also becomes the same, and the tracking error becomes zero. Furthermore, when center deviation (track deviation) occurs, the polarity and level change depending on the direction and amount of deviation. As described above, by selecting the output from the oscillator 35 using the selector 36 for each track to be reproduced, it is possible to generate a tracking error signal for any track.

Next, the recording operation will be explained. In FIG. 1, when the switch 18 is turned on and the switch 19 is connected to the terminal 19b opposite to that used during reproduction, the differential amplifier 14 and the adder 11 are connected, and the magnetic head 1 and the recording amplifier 20 are also connected. After this operation is completed, the recording signal is recorded via the recording amplifier 20 and the magnetic head 1 onto a magnetic recording medium in which adjacent recording tracks are successively formed. Further, when the reference tape 50 is reproduced, the displacement pattern data of the electromechanical transducer 2 stored in the memory 16 is transferred to the D/A converter 1.
7 converts it into an analog signal and inputs it to the differential amplifier 14. This analog signal is compared with the output signal of the position sensor 4 on the electromechanical transducer 2 by the differential amplifier 14,
The difference is fed back to the electromechanical transducer 2 via the adder 11 and the driver 12, and the electromechanical transducer 2 and magnetic head 1 record the signal on the magnetic recording medium with the same track curvature as the reference tape 50. controlled by. Further, during this operation, the A/D converter 15 does not operate, and the contents of the memory 16 are retained.

According to the above embodiment, the linearity of the recording track recorded on the magnetic recording medium does not depend on the precision of the tape running guide member or the rotating cylinder, and the linearity of the recording track recorded on the magnetic recording medium can be achieved by
When this magnetic recording medium (tape) is attempted to be reproduced by another rotating magnetic recording/reproducing device (during compatible reproduction), the tracking amount of the magnetic head 1 is suppressed as much as possible, and the servo The time deviation (track deviation) can be reduced. Therefore, it is very suitable for a rotary magnetic recording/reproducing device aiming at improving recording density by narrower tracks.

[0021] In the above embodiment, the electromechanical transducer 2
Although an example using a piezoelectric element has been described, a voice coil type electromechanical transducer as shown in FIG. 8 may also be used. To explain this simply, when a current is passed through the coil 2d wound around the bobbin 2c, the bobbin 2c reciprocates in the vertical direction in the figure, and the gimbal spring 2e fixed to the bobbin 2c and the magnetic head 1 also move in the vertical direction, that is, magnetically. It can swing in a direction perpendicular to the scanning direction of the head 1. Furthermore, when this voice coil type electromechanical transducer is used, the position sensor 4 based on strain detection described in the above embodiment cannot be used, and a magnet 4a is disposed on the gimbal spring 2f as shown in FIG. It is necessary to use a position sensor provided with a Hall element 4b for detecting the magnetic flux, that is, a position sensor that indirectly detects the displacement of the magnetic head 1 by the amount of magnetic flux.

Further, in the above embodiment, the A/D converter 15 converts the track scanning pattern into digital data and stores it in the memory 16, which is built into the apparatus, but the track scanning pattern writing circuit (external to the apparatus) (not shown), the track scanning pattern is stored in the read-only memory 16, and as shown in FIG.
The /D converter 15 may be omitted.

[0023]

As described above, according to the present invention, when recording signals on a magnetic recording medium, track linearity can be obtained with accuracy comparable to that of a reference tape, and compatible reproduction can be easily obtained.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a first embodiment of the device of the present invention.

FIG. 2 is an explanatory diagram of pilot signals recorded on each track of the reference tape according to the present invention.

FIG. 3 is an explanatory diagram of a scanning state of a reference tape by a magnetic head according to the present invention.

FIG. 4 is a configuration diagram of a tracking error detection circuit.

FIG. 5 is an explanatory diagram of the operation of the electromechanical transducer according to the present invention.

FIG. 6 is a layout diagram of a position sensor according to the present invention.

FIG. 7 is a configuration diagram of a conventional device.

FIG. 8 is a sectional view of another embodiment of the electromechanical transducer according to the present invention.

FIG. 9 is a configuration diagram of a second embodiment of the device of the present invention.

[Explanation of symbols]

1 Magnetic head 2 Electromechanical conversion element 4 Position sensor 6 Tracking error detection circuit 16 Memory 50 Standard tape

Claims (1)

[Claims] 1. A magnetic recording and reproducing device that sequentially forms adjacent recording tracks on a magnetic recording medium to record and reproduce signals, comprising: a magnetic head that is swingable in a direction perpendicular to a scanning direction; a position sensor that detects the position;
A tracking error detection circuit that detects the relative deviation between the scanning locus of the magnetic head and the recording track, a memory that records the detection signal of the position sensor, and a reference tape whose recording track has good linearity in advance is followed by the magnetic head. let me,
A means for detecting the amount of displacement of the magnetic head at this time with a position sensor and storing it in the memory, and a means for performing feedback control so that the amount of displacement in track scanning of the magnetic head during recording matches the amount of displacement stored in the memory. A magnetic recording and reproducing device characterized by comprising: