JPS60136974A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To shorten the signal recording time and to prevent the tracking accuracy at reproduction from being deteriorated by recording a data information signal and a pilot signal at the same time and controlling the data information signal at reproduction so as not to be shifted from the track. CONSTITUTION:A comparator 6 outputs a voltage at recording so as to continue to move a multi-track head 3. An output potential is OV at a desired position so as to finish the positioning of the multi-track head 3. A signal of an oscillator 17 is applied to a servo track head 3b, a signal of an oscillator 19 is supplied to a servo track head 3c, a data signal from an input terminal 21 is applied to a data track head 3a and they are recorded. A tracking error signal is amplified by an amplifier 9 and a power amplifier 10 at reproduction, the multi-track head 3 is moved by an electric-displacement transducer 11, the output voltage is OV when the track shift amount is zero, then the head is scanned on a data track at all times so as to obtain an excellent reproducing signal.

Description

[Detailed Description of the Invention] (Field of Application of the Invention) The present invention relates to a magnetic recording/reproducing device, which records data information signals on a magnetic recording medium with high density, and in particular improves the accuracy of the reproducing head during reproduction. The present invention relates to a magnetic recording/reproducing device suitable for tracking.

[Background of the invention]

Generally, when data information is recorded at high density on a magnetic recording medium, adjacent recording tracks are in contact with each other.

Or, since they partially overlap, highly accurate tracking of the playback head is required during playback.

The prior art will be explained with reference to FIG.

FIG. 1 is an explanatory diagram of a recording pattern on a magnetic recording medium by a conventional magnetic head, with arrows indicating the rotation direction of the magnetic recording medium.

On the magnetic recording medium 1, a pilot signal having a frequency f is recorded onto a data track T for recording data information and an adjacent track T2 by a magnetic head 2 for recording and reproducing information, and then the data track Data information is recorded onto the data track T, and a pilot signal having a frequency f2 is further recorded onto the track T1 adjacent to the data track T.

During reproduction, if there is a track misalignment in the reproduction head 2 related to the magnetic head, the reproduction signal is mixed with a pilot signal of the frequency f or f2, so the reproduction signal cannot be used to detect the frequencies f and f2. The reproducing head 2
scans on the data information signal track (hereinafter referred to as data track) without shifting the track deviation, thereby obtaining a good reproduced signal.

However, in this case, during recording, the same magnetic head 2
data track T, and a track for recording pilot signals (hereinafter referred to as servo track) T2-T.
Since recording is performed on the data track T, there is a drawback that the time efficiency during recording is reduced, and during the above recording, the data track T, and servo track T.
T.

It is difficult to maintain a constant positional relationship, and this has the disadvantage of deteriorating tracking accuracy during playback.

``[Object of the Invention] The present invention has been made in order to solve the problems of the prior art described above, and aims to shorten the time for recording data information signals and pilot signals, and to To provide a magnetic recording and reproducing device which makes the positional relationship strict, prevents deterioration of tracking accuracy during reproduction, and obtains a good reproduction signal of data information.

That is the purpose.

[Summary of the invention]

The configuration of the magnetic recording/reproducing apparatus according to the present invention includes a data track head for recording and reproducing data information signals, and a data track head adjacent to the data track head. A multi-track head arranged with a plurality of servo track heads for recording pilot signals is used to record a data information signal on a magnetic recording medium on the data information signal track, and to record a plurality of pilot signals with different frequencies on the data information signal track. The structure is configured to simultaneously record information on servo tracks adjacent to the signal track, and at the time of reproduction, the position of the multi-track head is determined by an electric-displacement conversion element based on a mutual comparison of reproduction levels related to a plurality of pilot signals. The control circuit includes an electric-displacement conversion element so that the data track head of the multi-track head can scan data information signals without shifting the track.

(Embodiment of the Invention) An embodiment of the present invention will be described below with reference to FIGS. 2 to 6.

FIG. 2 is a plan view of a multi-track head provided in a magnetic recording/reproducing apparatus according to an embodiment of the present invention, and FIG.
FIG. 2 is an explanatory diagram of a recording pattern on a magnetic recording medium by a multi-track head, FIG. 4 is a control circuit block diagram of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, and FIG.
A diagram showing the relationship between the frequencies of the modulated data signal and the pilot signal, and FIG. 6 is an explanatory diagram showing the positional relationship between the recording track and the reproduction track.

In FIG. 2, a multi-track head 3 is composed of a data track head 3a for recording and reproducing data information signals and servo track heads 3b and 3c for recording two pilot signals. In order to avoid magnetic interference between tracks during recording, head gaps 4a and 4b in the head traveling direction are provided as shown in the figure.
, 4c are arranged so that the positions of the tracks are different from those of adjacent tracks. As shown in FIG. 3, a data information signal track T (hereinafter referred to as a data track) and a track T for recording a pilot signal are recorded onto the magnetic recording medium 1 by the multi-track head 3.

T1 (hereinafter referred to as servo track) will be recorded. Note that the arrow in FIG. 3 indicates the direction of rotation of the magnetic recording medium.

The operation of the magnetic recording/reproducing apparatus using the multi-track head 3 will be explained with reference to the control circuit block diagram shown in FIG.

First, the operation during recording will be explained. When recording data information onto the magnetic recording medium 1, it is necessary to position the multi-track head 3 at a predetermined position. In this regard, a voltage corresponding to the desired track position is generated from the track position setting circuit 5, and the signal is input to a comparator 6, which generates a voltage. The output is connected to the selector switch 8 to the W side by the selector switch control circuit 7, and the amplifier 9
The above signal is amplified, the output signal is amplified by power amplification@10, and the multi-track head 3 is moved in the radial direction of the magnetic recording medium 1 by the electric-displacement conversion element 11. A displacement sensor 12 is attached to this electric-displacement conversion element 11, and the voltage changes according to the position of the multi-track head 3. The output voltage from the displacement sensor 12 enters an amplifier 13 where the voltage is amplified, and its output type is entered into a catfish comparator 6.

The comparator 6 outputs a voltage until the track position set by the track position setting circuit 5 is reached, and continues to move the multi-track head 3. When the multi-track head 3 moves to the desired track position, the comparator 6 outputs a voltage. The output potential becomes ov, the multi-track head 3 stops at that position, and positioning is completed.

When the positioning of the multi-track head 3 is completed, the changeover switch control circuit 7 connects the changeover switches 14, 15 and 16 to the W side, and the light amplifier 18 amplifies the signal from the oscillator 17 which oscillates at the frequency f. , the output signal is input to the servo track head 3b, and one frequency f2
The signal of the oscillator 19 that oscillates is amplified by the write amplifier 20, and the output signal is input to the servo track head 3c.
Further, the data signal coming from the input terminal 21 is modulated by the modulator 22, the signal is amplified by the write amplifier 23, and inputted to the data track head 3a, whereby the modulated data signal and the pilot signal with different frequencies are generated. At the same time, data is recorded onto the magnetic recording medium 1 by the multi-track head 3 as shown in FIG. At this time, the oscillation frequency 5. of the oscillator 17.19 in FIG. Assuming that the frequency component band of the modulated data signal is from f3 to f, Hz as shown in FIG. f,≠f1, or f, -52≠f1, or f, -f, -:F, or f4-f.

(Kf.

It is necessary to choose f,,f2 such that.

Next, the action during playback will be explained. During playback, the changeover switch control circuit 7 connects the changeover switch 16 to the r side, so that only the data track head 3a performs the playback operation. The reproduced signal from the data track head 3a is amplified by a preamplifier 24, and is then amplified by a bandpass filter 2.
5 passes only the modulated data signal, the signal is amplified by an amplifier 26, demodulated into a data signal by a demodulator 27, and outputted to an output terminal 28.

During the above-mentioned reproduction, due to expansion and contraction of the magnetic recording medium 1 due to temperature changes and positioning errors of the head access mechanism (not shown), as shown in FIG. The track T of the data signal may deviate from the track T. In this way, when track deviation occurs, the frequency component of the pilot signal, or f2, is mixed into the reproduced signal from the data track head 3a. From this mixed pilot signal, only the pilot signal is extracted by a bandpass filter 29 with a center frequency f and a bandpass filter 30 with a center frequency f2 shown in FIG.
The output signals of these bandpass filters 29 and 30 are:
The amplitude signals of frequencies f and f2 rectified by the detectors 31 and 32 enter the differential amplifier 33, and the amount of tracking error of the multi-track head 3 can be determined from the amplitude value of this output signal.

At the time of reproduction, the changeover switch 8 is connected to the R side by the changeover switch control circuit 7, so that the tracking error signal is amplified by the amplifier 9, and further power amplified by the power amplifier 10, and then converted into an electric displacement signal. Conversion element 1
1, the multi-track head 3 is moved in the direction in which the amount of track deviation decreases, and when the amount of track deviation becomes zero, the output voltage of the differential amplifier 33 becomes 0V, and the movement of the multi-track head 3 is stopped. The track head 3a always scans over the data track T, and a good reproduced signal can be obtained.

As described above, according to this embodiment, the pilot signal for performing tracking control when reproducing the data track T is recorded simultaneously with the data information signal by the multi-track head 3, so that the recording time is shortened. is,
A recording and reproducing device capable of high-speed access is obtained.

Also, by using the multi-track head 3 during recording, data track T, servo track T2. T
Since the positional relationship between , , and the like is strict, tracking accuracy is improved, track density is increased, and a recording/reproducing device with a high recording capacity can be provided.

〔Effect of the invention〕

As described above, according to the present invention, the time for recording the data information signal and the pilot signal is shortened, and the positional relationship between the data track and the servo track is kept close during recording, thereby reducing tracking accuracy during playback. Therefore, it is possible to provide a magnetic recording and reproducing device that prevents the problem from occurring and obtains a good reproduction signal of information.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a recording pattern on a magnetic recording medium by a conventional magnetic head, FIG. 2 is a plan view of a multi-track head used in a magnetic recording/reproducing apparatus according to an embodiment of the present invention, and FIG. is an explanatory diagram of a recording pattern on a magnetic recording medium by the multi-track head of FIG. 2, FIG. 4 is a block diagram of a control circuit of a magnetic recording and reproducing apparatus according to an embodiment of the present invention, and FIG. A diagram showing the relationship between the frequencies of pilot signals, and FIG. 6 is an explanatory diagram showing the positional relationship between the recording track and the reproduction track. 1...Magnetic recording medium, 3...Multi-track head. 3a...Data track head, 3b, 3c...Servo track head, T...Data information signal track (data track), Ts-Ts...Servo track, 5...Track position setting circuit, 6... Comparator, 11... Electricity-displacement conversion element, 17.19...
Oscillator, 31.32...detector. j'112] Kosai 3

Claims (1)

[Claims] 1. A multi-track head consisting of a data track head for recording and reproducing data information signals and a plurality of servo track heads adjacent to the data track head for recording pilot signals is used to record and reproduce data on a magnetic recording medium. The data information signal is simultaneously recorded on the data information signal track and a plurality of pilot signals having different frequencies are simultaneously recorded on the servo I to rack adjacent to the data information signal track, and when reproducing the data information signal,
The position of the multi-track head is moved by an electric-displacement conversion element based on a mutual comparison of reproduction levels related to a plurality of pilot signals, and the data track head of the multi-track head scans the data information signal without shifting the track. 1. A magnetic recording/reproducing device comprising a control circuit having an electric-displacement conversion element.