JPH08339519A - Recording and reproducing device - Google Patents

Abstract

PURPOSE: To form an enough narrow track by using a detection track. CONSTITUTION: A set of two detection tracks Ts1 and Ts2 are provided parallel to a prescribed plural number of data tracks Td1-Tdm in the width direction of a recording medium 1. On these detection tracks Ts1 and Ts2, servo signals in different frequencies from each other are recorded. Moreover, the data tracks Td1-Tdm are provided with their respective recording and reproducing heads Hd1-Hdm, while the detection tracks Ts1 and Ts2 are provided with one detecting head Hs. Then, a multiple head 2 consisting of these heads is constituted to be movable in the width direction of the recording medium 1 by an actuator 3. Then, the detection tracks Ts1 and Ts2 are simultaneously detected by the detecting head Hs, and these regenerative signals are separated by filters 41 and 42 to discriminate their respective servo signals, which are then supplied to a differential amplifier 5, and this differential output signal is supplied to the actuator 3 to perform a tracking servo.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus suitable for use in, for example, a multi-channel fixed head recorder capable of recording / reproducing video signals with a fixed head.

[0002]

2. Description of the Related Art For example, in a multi-channel fixed head recorder capable of recording and reproducing a video signal with a fixed head, a large number of parallel tracks are provided in the width direction of a recording medium. Then, a large number of these parallel tracks are simultaneously traced by a plurality of fixed heads for recording and reproduction. In this case, the width of each track on which recording / reproduction is performed can be narrowed to 90 μm or less, for example, by improving recording characteristics and improving error correction technology particularly in digital recording.

However, when recording / reproducing is performed using such a large number of parallel tracks, there arises a problem of positional relationship between each track and the fixed head, that is, tracking accuracy.

In particular, this uses a composite head in which fixed heads of the number 1 / N (N is an integer) of the number of parallel tracks are integrated, and the composite head is moved in the width direction of the recording medium. With an apparatus capable of recording N programs, it is not possible to obtain sufficiently high tracking accuracy due to the movement of the composite head. Therefore, the track pitch could not be set to 195 μm or less, for example, in order to provide a track interval that is not affected by the tracking accuracy.

That is, in the prior art, there is a limit to narrowing the track pitch due to the problem of tracking accuracy, and therefore the possibility of narrowing the track due to the improvement of recording characteristics cannot be fully utilized. there were.

[0006]

This application has been made in view of the above point, and the problem to be solved is that the conventional technique has a problem in tracking accuracy. It is said that the track could not be narrowed sufficiently.

[0007]

For this reason, in the present invention, first and second detection tracks on which predetermined servo signals are recorded are provided in parallel with the parallel tracks on the recording medium. Tracking servo is performed using the signal reproduced by the detection head.

[0008]

According to this, by providing the detection track, it is possible to sufficiently narrow the track, and by reproducing the detection track by one detection head, recording using the detection track with a simple structure is performed. Playback can be performed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS That is, according to the present invention, when a large number of parallel tracks are provided on a recording medium to record / reproduce a signal, a predetermined servo signal is recorded parallel to the parallel tracks on the recording medium. Two detection tracks are provided and a fixed head is used to record / reproduce a large number of parallel tracks on the recording medium, and a servo signal from the detection track reproduced by one detection head integrated with the fixed head is used. The tracking servo between the fixed head and the parallel track is performed.

The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an example of a recording / reproducing apparatus according to the present invention.

In FIG. 1, a large number of parallel tracks are provided in the width direction of the recording medium 1. These parallel tracks are a plurality of predetermined data tracks Td1, Td2 ...
-Tdm has two detection tracks Ts1 and T2.
s2. And these detection tracks Ts
1, Ts2 and data tracks Td1, Td2 ... Td
For example, the above-mentioned N sets are provided in parallel with the width direction of the recording medium 1.

Further, in this case, the detection tracks Ts1, Ts
Servo signals of different frequencies are recorded in s2, for example. Then, these detection tracks Ts1 and Ts
Reference numerals 2 are provided at predetermined positions in the width direction of the recording medium 1 at predetermined intervals (may be 0) so as to extend in the longitudinal direction of the recording medium 1 in parallel.

Further, in the recording / reproducing apparatus, for these data tracks Td1, Td2 ... Tdm,
Recording / reproducing heads Hd1, Hd2 ... Hdm are provided respectively. Along with that, the detection tracks Ts1 and Ts2
In contrast, one detection head Hs is provided at an intermediate position between these detection tracks Ts1 and Ts2.

Further, these recording / reproducing heads Hd1, H
The d2 ... Hdm and the detection head Hs are formed as one body. The composite head 2 formed in one of these heads is configured to be moved in the width direction of the recording medium 1 by an arbitrary actuator 3.

During recording and reproduction, the detection head Hs simultaneously reproduces the servo signals recorded on the detection tracks Ts1 and Ts2. Further, this reproduction signal is supplied to the filters 41 and 42, and the above-mentioned detection track Ts1,
For example, servo signals of different frequencies recorded in Ts2 are discriminated. The discriminated servo signal is supplied to the differential amplifier 5, and the differential output signal from the differential amplifier 5 is supplied to the above-described actuator 3 to perform tracking servo.

Therefore, in this recording / reproducing apparatus, for example, as shown by A1 in FIG. 2, when the center of the detection head Hs passes through the centers of the detection tracks Ts1 and Ts2 and the detection head Hs is equally applied to the detection tracks Ts1 and Ts2. The output signals of the detection head Hs from the filters 41, 4
The levels of the respective servo signals discriminated in 2 are almost equal as shown by A2 in FIG.

On the other hand, when the detection head Hs is displaced above the detection tracks Ts1 and Ts2 as shown by B1 in FIG. 2, the filter 4 is detected from the output signal of the detection head Hs.
As for the level of each servo signal discriminated by Nos. 1 and 42, for example, the level of the servo signal recorded on the upper detection track Ts1 becomes large as shown by B2 in FIG. 2, and is recorded on the lower detection track Ts2. The level of the servo signal decreases.

Further, as shown by C1 in FIG.
When s is displaced below the detection tracks Ts1 and Ts2, the filters 41 and 42 are detected from the output signal of the detection head Hs.
As for the level of each servo signal discriminated by, for example, the level of the servo signal recorded on the upper detection track Ts1 becomes smaller as shown by C2 in FIG. 2, and the level of the servo signal recorded on the lower detection track Ts2 becomes smaller. The level increases.

Therefore, the differential amplifier 5 detects the level difference between the servo signals discriminated by the filters 41 and 42. Then, by controlling the drive of the actuator 3 so that the difference between the levels becomes zero, tracking control is performed so that the detection head Hs passes through the centers of the detection tracks Ts1 and Ts2.

Then, by this tracking control,
As shown in FIG. 3, for example, the width of each detection track Ts is 20 μm, and the width of each data track Td is 90 μm.
m, and the track pitch is 100 μm, good recording and reproduction can be performed. Note that FIG. 4 shows a result of measuring the output level of the recording / reproducing head Hd thus recorded / reproduced over the extension 100 m of the recording medium 30.

That is, as is apparent from FIG. 4, the fluctuation of the reproduction output can be kept within ± 3 dB in the recording medium of the above embodiment. As a result, the track density can be increased from 51 tracks / mm in the conventional fixed head device to 100 tracks / mm, and the recording density can be improved 1.9 times or more.

Therefore, in this recording / reproducing apparatus, there is a problem in the tracking accuracy in the conventional technique, and therefore the tracks which could not be sufficiently narrowed are made parallel to the parallel tracks on the recording medium. By providing the first and second detection tracks on which a predetermined servo signal is recorded and performing the tracking servo using the signal reproduced by one detection head, it is possible to sufficiently narrow the track. By reproducing the detection track with one detection head, it is possible to perform recording / reproduction using the detection track with a simple configuration.

In the above-described embodiment, the detection tracks Ts1 and Ts2 are designed to record servo signals having different frequencies, for example. However, when the frequencies are different, the filter 4 for discriminating the servo signals is used.
It is necessary to arrange the characteristics of Nos. 1 and 42 so that the output levels become equal at the target frequency.

On the other hand, the embodiment of FIG. 5 discriminates the servo signals on the time axis. For example, as shown in A of FIG. 5, the servo signals are alternately recorded on the detection tracks Ts1 and Ts2. , The output signals of the detection head Hs are discriminated by the sample hold circuits 43 and 44 at the timings when these signals are recorded.

Then, these sample and hold circuits 4
The differential amplifier 5 detects the level difference between the servo signals discriminated by 3 and 44, and drives and controls the actuator 3 (not shown) so that the level difference becomes zero. This also causes the detection head Hs to move the detection tracks Ts1 and Ts.
The tracking can be controlled so as to pass through the center of s2.

Alternatively, as shown in FIG. 5B, the servo signal is continuously recorded on one detection track Ts1 and the servo signal is intermittently recorded on the other detection track Ts2. Then, the output signal of the detection head Hs is
The sample hold circuit 4 operates at the timing when the servo signal is recorded on the detection track Ts2 and at the timing when the servo signal is not recorded.
Discriminate using 3, 44.

Therefore, in this case, when the detection head Hs is tracked so as to pass through the centers of the detection tracks Ts1 and Ts2, the output of the sample hold circuit 43 at the timing when the servo signal is recorded is the sample at the timing other than that. It is twice the output of the hold circuit 44.

Therefore, the differential amplifier 5 detects the difference between the level at which the output of the sample-hold circuit 43 is halved by the attenuator 45 and the level of the output of the sample-hold circuit 44, and the difference between these levels becomes zero. By driving and controlling the actuator 3 (not shown), tracking control can be performed so that the detection head Hs passes through the centers of the detection tracks Ts1 and Ts2.

In the embodiment shown in FIG. 5,
Since the servo signal can have a single frequency, the influence of the frequency characteristic of the circuit for detecting the servo signal can be eliminated. The detection tracks Ts1 and Ts
The interval of 2 may be 0.

Further, FIG. 6 is a schematic diagram showing the construction of the main part of an example of a recording medium manufacturing apparatus applied to the recording / reproducing apparatus of the present invention.

In FIG. 6, a wide recording medium 1 is unwound from a wound substrate 10 and supplied to a cutting machine 50 composed of upper and lower rotary blades 51 and 52. The recording media 11, 12 ... 1n cut into a predetermined width by the cutting machine 50 are alternately separated and wound around the winding shafts 61 and 62, respectively.

Further, the cutting machine 50 and the winding shafts 61 and 62
Means 71, 72 for adjusting the winding tension of the recording media 11, 12, ...
As a result, adjustment is performed so that the recording media 11, 12 ... 1n are wound around the winding shafts 61 and 62 with a predetermined tension.

At the same time, recording heads 81, 82 ... 8n for the detection tracks Ts1, Ts2 are provided between the cutting machine 50 and the winding shafts 61, 62. Then, the recording heads 81, 82 ... 8n record the detection tracks Ts1 and Ts2 on predetermined portions of the recording media 11, 12 ... 1n, respectively.

Furthermore, in this recording medium manufacturing apparatus,
The recording of the detection track Ts is performed by the recording mediums 11, 12, ...
.. 1n may be performed immediately before the cut recording media 11, 12, ... 1n are stored in the cassette housing. FIG. 7 is a schematic diagram showing a configuration of a main part of another example of the manufacturing apparatus when recording the detection tracks Ts1 and Ts2 in this way.

In FIG. 7, for example, the winding shaft 61
The recording medium 11 wound on the paper is unwound again. The recording medium 11 is guided by a guide roller G and a cassette housing C
It is wound up on the reel R stored in. A recording head 81 is provided on the way of the recording medium 11.
The recording head 81 detects the detection tracks Ts1 and Ts2.
Is recorded.

Even in this case, the recording of the detection tracks Ts1 and Ts2 can be performed when the recording medium is manufactured. In this case, for example, when the servo signal is composed of a tone signal having a predetermined frequency, the recorded frequency may change depending on the moving speed of the recording medium, and the servo signal may not be reproduced well.

Therefore, in this example, the guide roller G
A frequency generator FG is provided on the rotating shaft of the. Then, the rotation of the drive motor M of the reel R is controlled according to the rotation speed of the guide roller G (corresponding to the transfer speed of the recording medium) detected by the frequency generator FG so that the transfer speed of the recording medium falls within a predetermined range. Control can be performed.

Alternatively, the oscillation frequency of the oscillator OSC of the servo signal supplied to the recording head is controlled according to the rotation speed of the guide roller G detected by the frequency generator FG, and the recorded servo signal is frequency-modulated, Control can be performed so that the frequency of the recorded servo signal is within a predetermined range.

Further, control can be performed by combining these methods. This control can also be applied to the embodiment shown in FIG.

Thus, according to the above-described recording / reproducing apparatus, when a large number of parallel tracks are provided on the recording medium to record / reproduce signals, a predetermined servo signal is recorded on the recording medium in parallel with the parallel tracks. The first and second detection tracks are provided, and the fixed head is used to record and reproduce a large number of parallel tracks on the recording medium.
Tracking servo between the fixed head and the parallel track is performed by using the servo signals from the detection tracks reproduced by the individual detection heads, whereby the track can be sufficiently narrowed and one detection head is provided. It is possible to perform recording / reproduction using a detection track with a simple configuration.

[0041]

According to the present invention, the first and second detection tracks on which predetermined servo signals are recorded are provided in parallel with the parallel tracks on the recording medium, and these are reproduced by one detection head. By performing tracking servo using a signal, it is possible to sufficiently narrow the track, and it has become possible to perform recording / reproduction using a detection track with a simple configuration.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of an example of a recording / reproducing apparatus to which the present invention is applied.

FIG. 2 is a diagram for explaining the explanation.

FIG. 3 is a diagram for explaining the explanation.

FIG. 4 is a diagram for explaining the explanation.

FIG. 5 is a diagram for explaining another example of the recording / reproducing apparatus to which the present invention is applied.

FIG. 6 is a configuration diagram of a main part of an example of a recording medium manufacturing apparatus to which the recording / reproducing apparatus of the present invention is applied.

FIG. 7 is a configuration diagram of a main part of another example of a recording medium manufacturing apparatus to which the recording / reproducing apparatus of the present invention is applied.

[Description of Reference Signs] 1 recording medium Td1, Td2 ... Tdm predetermined plural data tracks Ts1, Ts2 two detection tracks Hd1, Hd2 ... Hdm recording / reproducing head Hs one detection head 2 composite head 3 Arbitrary actuator 41, 42 Filter 5 Differential amplifier

Claims (3)

[Claims] 1. When recording and reproducing a signal by providing a large number of parallel tracks on a recording medium, first and second detection in which predetermined servo signals are recorded on the recording medium in parallel with the parallel tracks. A track is provided, and a fixed head is used to record / reproduce a large number of parallel tracks on the recording medium, and a servo signal from the detection track reproduced by one detection head integrated with the fixed head is used. A recording / reproducing apparatus adapted to perform tracking servo between the fixed head and the parallel track. 2. The recording / reproducing apparatus according to claim 1, wherein servo signals having different frequencies are recorded on the first and second detection tracks, and the detection tracks reproduced by the one detection head are recorded. A recording / reproducing apparatus adapted to perform tracking servo between the fixed head and the parallel track by using the servo signal obtained by discriminating the reproduction signal of the above-mentioned different frequency. 3. The recording / reproducing apparatus according to claim 1, wherein servo signals are recorded on the first and second detection tracks at different timings, and the servo signals are reproduced from the one detection head. The recording / reproducing apparatus is adapted to perform the tracking servo between the fixed head and the parallel track by using the servo signal obtained by discriminating the reproduction signal from the above-mentioned different timing.