JPH0287302A - Rotating head type recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain high speed dubbing without imposing a load onto a head and a recording medium by providing the mode recording a signal onto a recording medium carried at a prescribed speed through the use of n-set of rotary heads among nXm sets of rotary heads and the recording mode of a signal through the use of all the rotary heads on a recording medium carried at a speed being m-time of the prescribed speed. CONSTITUTION:The 1st mode is provided, in which n-set of rotary heads are used among nXm sets of rotary heads ((n), (m) are integers being '1' or over and '2' or over respectively) HA-HH arranged closely onto a recording medium T carried at a prescribed speed so as to record a signal. Moreover, the 2nd mode is provided, in which all of the nXm sets of rotary heads HA-HH are used so as to record a signal onto the recording medium T in a direction crossing with the rotating face at a prescribed speed on the recording medium T carried at a speed being m-time of the 1st mode. Thus, the time required for recording reproduction in the dubbing mode is 1/m with respect to a normal recording reproduction mode but since it is not required to change the drive speed of the rotary heads, high speed dubbing is attained without imposing any load onto the heads and the recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotary head type recording and reproducing device, and particularly to a rotary head type recording and reproducing device having a high-speed dubbing function.

[Prior Art] Conventionally, a method for performing high-speed dubbing in a rotary head type recording/reproducing device, such as a video tape recorder (VTR), is to increase the running speed of a magnetic tape by m times (m is an integer of 2 or more), and to increase the speed of rotation. The number of rotations of the head is also multiplied by m, and m
Techniques are known in which a signal reproduced from one device is recorded on another device at twice the speed.

[Problems to be Solved by the Invention] However, in the above method, the relative speed between the rotating head and the magnetic tape increases by m times, which places a large burden on the head and tape, which may cause damage to the head or tape. There was a risk that he might be invited. Furthermore, the frequency of the signal for recording and reproducing becomes m times the band, and in devices that originally handle wideband signals, it may be difficult for circuit systems such as amplifiers to follow this frequency. In particular, in a digital VTR that must record and reproduce digital signals at extremely high data rates, it is impossible to process data during dubbing.

Against this background, it is an object of the present invention to provide a rotary head type recording device and a reproducing device that are capable of high-speed dubbing without placing a burden on the head, recording medium, or the like.

[Means for Solving the Problems] For this purpose, in the rotary head type recording device of the present invention, two heads ( A first mode in which signals are recorded using only n rotating heads out of (n×m) rotating heads (n is an integer of 1 or more, m is an integer of 2 or more); and The above (n x
m) a second mode in which signals are recorded using all of the rotating heads.

In addition, in the rotary head type reproducing device of the present invention, (n×m) pieces (n is 1 or more, m is 2 A first D mode in which signals are reproduced using only n rotary heads among the n rotary heads (an integer greater than or equal to); The second mode includes a second mode in which signals are recorded using all of the (n×m) rotating heads that are displaced in a direction intersecting the plane.

[Function] With the above configuration, the time required for recording and reproducing in the second mode (dubbing mode) is 1/m compared to the first mode (normal recording and reproducing mode), but the time required for recording and reproducing in the second mode (dubbing mode) is 1/m. Since there is no need to substantially change the rotational speed, no burden is placed on the head or the recording medium.

[Example] Below, as an example of the present invention, n=2. A digital VTR in the case where m=2 will be explained.

FIG. 1 is a block diagram showing a schematic configuration of a digital VTR as an embodiment of the present invention.

In the figure, HA, HB, HC, and HD are rotary heads that perform recording and reproduction in the normal recording and reproduction mode, HE, HF, HG, and HH.
is a rotating head used only for recording and reproducing in dubbing mode.

2A and 2B are diagrams showing the arrangement of each rotating head of the digital VTR shown in FIG. This is an electro-mechanical conversion element for displacing the motor in the direction of the rotation axis, and is composed of a semicircular bimorph plate. Regarding the operation of this bimorph plate, please refer to JP-A-55-1
13127 and the like are well known, so the description thereof will be omitted.

As shown, the heads HA, HB, HE, and HF are arranged close to each other, and are installed at the free end of the bimorph 2a as shown in the plan view of FIG. 2(A). 3a in the diagram
, 3b are fixing screws that fix the bimorph 2a to the cylinder l. Similarly, heads HC, HD, HG, HH
are arranged close to each other, and the fixing screws 4a, 4b
It is installed at the free end of bimorph 2b, which is fixed to cylinder l. Figure 2 (B) is a developed view of these heads developed on the cylindrical surface of cylinder 1, and as shown in the figure, head H
Head HB, HD for A, HC, HE, HG.

HF and HH have different azimuth angles.

Also, for heads HA, HB, HE, and HF, head HC
, HD, HG, and HH have a rotational phase difference of 180'', and if the displacement amounts of the bimorphs 2a and 2b are both O, they are mounted at the same position in the rotational axis direction.Head HA,
The positions of adjacent heads of HB, HE, and HF in the direction of the rotation axis differ by a predetermined distance d, as shown in FIG. 2(B). This distance jlld is made approximately equal to the track pitch.

The operation of the digital VTR of this embodiment will be explained below.

First, the operation during normal recording will be explained.

The analog video signal input from the input terminal IO is A/
The data is digitized by a D converter 11 and then processed by a high-efficiency encoding circuit 1.
2 is input. The high-efficiency encoding circuit 12 is a circuit that reduces the data rate by utilizing image correlation, and includes, for example, a Sara sampling circuit, a predictive differential encoding circuit, a block encoding circuit, and the like. High efficiency encoding circuit 1
2. The digital signal whose data rate has been reduced is supplied to the data distribution circuit 13, where it is converted into two systems of digital signals, thereby further reducing the data rate of each system of digital signals.

The two systems of digital signals from the data distribution circuit 13 are supplied to ECC encoders 14a and 14b, respectively, where an error correction code (ECC) is added, data is exchanged, etc. The two systems of digital signals to which ECC has been added are subjected to well-known modulation in digital modulation circuits 15a and 15b, and are output as two systems of recording signals to switches 16a and 16.
It is supplied to the R side terminal of b.

Now, when the mode setting circuit 21 manually sets the device to the normal recording mode, the switches 16a and 1
6b is connected to the R side, and the two systems of recording signals are sent to switches 17a and 17b via switches 16a and 16b.
supplied to The switches 17a and 117b are controlled by a PG pulse that is inverted every time the cylinder l rotates 180'', and are connected alternately to the A and B11fi terminals. That is, the recording signal via the switch 17a is connected to the cylinder l t
) <180'' Each time the head HA and HC rotate, the recording signal is alternately connected to the heads HA and HC, and the recording signal via the switch 17b is similarly connected alternately to the heads HB and HD.

FIG. 3 is a diagram showing the recording pattern of the digital VTR of this embodiment. In FIG. 3, W is the rotation direction of each rotary head, and U is the conveyance direction of the tape T. Mode setting circuit 21 sets the normal recording mode, capstan control circuit 2
2 controls a capstan (not shown) so that the tape T is conveyed a distance four times the distance shown in FIG. 3 in one revolution of the cylinder l. In addition, the bimorph control circuit 23
Keep the displacements of a and 2b at 0. In FIG. 3, Tl to T8 are tracks, and @d' thereof almost coincides with d in FIG. 2(B). Now, if recording is performed on track TI by head HA, then head HB will be on track T2, head HC will be on track T3, and head H will be on track T4.
Recording is performed on tracks T5, T6 . T7,
Recording is also performed on T8 by heads HA, HB, HC, and HD, respectively.

Next, the operation during normal playback will be explained.

As in normal recording, the capstan control circuit 22 controls the capstan to transport the tape T by a distance fll14Jl, and the bimorph control circuit 23 controls the bimorphs 2a and 2b.
maintain the amount of displacement at 0, and further turn switches 17a and 17b to P.
Reproduction is performed by alternately connecting to the A and B terminals in response to the G pulse.

Therefore, the reproduction signals of heads HA, HC, heads HB, H
The playback signals of D are respectively connected to switch 1 as playback signals of the l system.
It is output from 7a and 17b. At this time, each head HA, HB, HC,
The capstan control circuit 22 operates so as to trace the azimuth track corresponding to the HD.

During normal playback, the switch 16 is set by the mode setting circuit 21.
a and 16b are connected to the P side, and the two systems of reproduction signals are supplied to equalizers (EQ) 25a and 25b, respectively.
The signal is returned to the same waveform as the recording signal and supplied to the demodulators 26a and 26b. The demodulators 26a, 26b are the modulators 15a, 1
5b is performed to demodulate the original digital signal.

The ECC decoders 27a and 27b perform data replacement and error correction on these digital signals, and the data synthesis circuit 2
Enter 8. The data synthesis circuit 28 is an error corrected 2
The system digital signals are converted into the original single system digital signal and supplied to the decoding circuit 29. The decoding circuit 29 performs the opposite process to that of the high-efficiency encoding circuit 12 to restore the data rate to the original value. The digital video signal restored in this way is supplied to the D/A converter 30, converted into an analog video signal, and output from the rear output terminal 10.

Next, the dubbing operation using this digital VTR will be explained. First, the operation when this digital VTR is used as a reproduction side during dubbing will be explained.

At this time, according to the mode setting circuit 21, the capstan control circuit 22 increases the tape transport speed to twice that of normal recording and playback (m).
Control the capstan so that the

This allows the four heads (A, HB, HE
, HF, HC, HD, HG, and HH can simultaneously trace four adjacent tracks, but
The tracing direction of each head on the tape T is different from that during normal recording and reproduction. Now, assuming that each head traces parallel to the tracks T1 to T8 during normal recording and reproduction, the tracing direction of the special number head whose tape T speed is doubled is the direction shown by the dotted line in FIG. 3. That is, the trace position of each head is shifted by two tracks between the track start and track end. Since reproduction cannot be performed in this case, the bimorph control circuit 23 controls the bimorph 2a,
2b is displaced to make the tracing direction of the head parallel to the track. A specific example of the bimorph control circuit 23 will be described below with reference to FIGS. 4 and 5.

FIG. 4 is a diagram showing an example of the bimorph control circuit 23 in FIG. 1, and FIG. 5 is a timing chart showing the waveform of the numbered part in FIG. The edge of one PG pulse (shown in FIG. 5(a)) generated by the pulse generator 51 is detected by the edge detector 5.
Detected at 2. This edge pulse from the edge detector 52 (shown in FIG. 5(b)) is input to the reset terminal of the counter 57.

The mode setting circuit 21 supplies a low level (Lo) signal during normal recording and reproduction and a high level (Hi) signal during tie-pin recording and reproduction to the terminal 54, and the AND gate 55.
The clock from the oscillator 53 can be gated only when the oscillator 56 is diving. AND gate 5 when PG pulse or Hi
6 gates the clock and counter 58 counts up. Further, the PG pulse or Lo eye gate 55M clock is gated, and the counter 57 counts up the clock. The output of counters 57 and 58 is D/A
Analog signals (Fig. 5(C), (d)
) as shown in ). At this time, the level V shown in FIG.
) A supplementary setting has been set that becomes the level to be shifted. As a result, the bimorphs 2a and 2b are controlled to shift by two tracks during the period in which each head traces the tape T. Accordingly, each head traces in a direction parallel to the track.

For example, heads HA, HB, HE, and HF are on track T1 in FIG. After reproducing T2, T3, and T4, head HC,
HD, HG, HH are track T5. T6, T7. Play T8. Switch l 7a, 17bJ7c, 17
d are each controlled according to the PG pulse, and output four systems of reproduction signals. These four systems of reproduction signals are returned to the original recording waveform by equalizers 38a, 38b, 38c, and 38d via the P side terminals of switches 32a, 32b, 33c, and 33d.

The outputs of the equalizers 38a, 38b, 38c, 38d are output from dubbing output terminals 39a, :19b, 39c,
It is output from 39d.

Finally, the operation when recording the four systems of dubbing signals output in this manner will be explained. The four systems of signals input from the dubbing input terminals 33a, 13b, 33c, and 33d are transferred to the switches 32a, 32b, 32c,
Switches 17a and 17b are connected via the R side terminal of 32d.

17c, 17d, and further heads HA, HB, H.
E, HF and heads HC, HD, HG, HH are alternately supplied. At this time, the capstan and bimorph 2a,
2b is controlled in the same manner as in the above-mentioned dubbing reproduction, and the recording track pattern becomes as shown in FIG. 3, and dubbing is completed.

In the digital VTR of the above-described embodiment, the tape speed during dubbing recording and reproduction can be doubled, so high-speed dubbing is possible. Further, since the rotational speed of the rotary head at this time is the same as that during normal recording and reproduction, no load is placed on the head and the tape, and data processing during dubbing can be performed in the same way as during normal recording and reproduction. Furthermore, dubbing is possible with a signal in the same band as the signal band during recording and reproduction, and there is no fear that dubbing will become impossible.

Furthermore, since the input/output data during dubbing is highly efficiently encoded data, the capacity of the signal line between the VTRs can be kept small.

FIG. 6 shows a digital VTR as another embodiment of the present invention.
In this figure, the same components as in FIG. 1 are given the same numbers.

During normal recording, the switch 18 is set by the mote setting circuit 21.
is connected to the N side, and the signal input from terminal lO is processed in the same way as the VTR shown in FIG.
17b.

It is recorded on tape T by heads HA, HB, HC, and HD.

During normal playback, heads HA, HB, HC.

A signal reproduced from the HD is processed via switches 17a, 17b and switches 16a, 16b in the same manner as in the VTR shown in FIG. 1, and a reproduced analog signal is obtained from the output terminal 31 via the N side of the switch 35.

During dubbing playback, bimorphs 2a and 2b are
It is controlled in the same way as the TR, and the capstan transports the tape T at twice the speed of normal recording and playback. On top of this, switch 17a, 17b,
Four systems of reproduction signals are obtained from 17c%17d. These four systems of reproduction signals are transmitted through equalizers 25a, 25b, 2
Demodulation circuits 26a, 526b, 26 via 5c, 25d
The signals are demodulated into the original digital signals by ECC decoders 27a, 27b, 27c, and 27d, and converted into two systems of digital signals by data synthesis circuits 28 and 28'. Here, the switch 35 is connected to the D side, and these two systems of digital signals are sent to the data synthesis circuit 3.
6 and further organized into l systems and outputted from the post-dubbing output terminal 37. The digital signal input from the terminal 2o during dubbing recording is input to the data distribution circuit 19 and is divided into two systems, one of which is sent to the data distribution circuit 13 via the terminal of the switch 18.

The other is supplied to the data distribution circuit 13'.

The four digital signals output from the data distribution circuits 13, 13' are sent to ECC encoders 14a, ! 4b,
Data is newly replaced and ECC added at 14c%14d, and is supplied to switches 17a, 17b, 17c%17d via the R side terminals of modulation circuits 15a, 15b, 15c, 15d switches 16a, 16b, 16c, 16d. Ru.

At this time, the bimorphs 2a, 2b and the capstan are controlled in the same way as during dubbing reproduction, and dubbing recording is completed while tracks are being formed as shown in FIG.

As mentioned above, the digital VTR shown in FIG. 6 is also capable of dubbing at double speed, and achieves the same effects as the embodiment shown in FIG. 1, such as not putting any burden on the tape or head. Although the circuit scale of the digital VTR of this embodiment is larger than that of the digital VTR shown in FIG. 1, the digital VTR shown in FIG. Better than VTR. Here, if the data compression rate of the high-efficiency encoding circuit 12 is 1/2, the data rate of the dubbing signal input and output from the terminal 20.37 is determined by the A/D converter 11.
This is the same as the digital signal output by the VTR, and can be transferred between VTRs. Furthermore, since error correction can be performed for each dubbing, data deterioration, that is, image deterioration, does not occur due to repeated dubbing.

In this specification, the number of heads (n x m) arranged close to each other is 4, and the number of recording channels (n) in the normal recording mode (first mode) is 21. Although the tape speed magnification (m) in the dubbing recording mode (second mode) for the mote was set to 2, the same effect can be obtained if n is 1 or more and m is 2 or more in boat fishing.

[Effects of the Invention] As explained above, according to the present invention, there is provided a rotary head type recording device and playback device that does not place a burden on the head or recording medium, can easily follow the circuit system, and can perform high-speed dubbing. A device is obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of a digital VTR as an embodiment of the present invention, FIGS. 3 is a diagram showing a recording pattern by the digital VTR shown in FIG. 1, FIG. 4 is a diagram showing a specific configuration example of the bimorph control circuit shown in FIG. 1, and FIG. 5 is a diagram showing the waveform of the numbered part in FIG. Timing chart, FIG. 6 is a digital VTR as another embodiment of the present invention.
FIG. 2 is a block diagram showing a schematic configuration of. In the figure, 1 is a cylinder, 2a and 2b are bimorphs as transition means, 1O is a video signal input terminal, 12 is a high-efficiency encoding circuit, 14a, 14b, 14c, and 14d are ECC encoders, 16a, 16b, 16c, 16d
is a recording/reproduction selector switch, 21 is a mode setting circuit, 22
23 is a capstan control circuit, 23 is a noheimorph control circuit, 27a, 27b, 27c, 27d are ECC decoders, 29 is a decoding circuit, 31 is a video signal output terminal, 33a
, 3b, '13c, 3'ld and 20 are dubbing input terminals, 39a, 39b, 39C139d and 31 are dubbing output terminals, HA, HB, HC, HD, HE, HF
, HG, and HH are rotating heads, respectively. γ5 days

Claims (4)

[Claims] (1) (n x m) pieces (n is 1 or more, m is 2) arranged close to each other on a recording medium being conveyed at a predetermined speed
A first mode in which signals are recorded using only n rotary heads among the n rotary heads (an integer greater than or equal to); The above (n×m) that is displaced in the direction intersecting the rotation plane
a second mode in which signals are recorded using all of the rotary heads. (2) The recording signal is a high-efficiency encoded digital signal, the input in the first mode is performed from the front stage of the high-efficiency encoding circuit, and the input in the second mode is the high-efficiency encoded digital signal. The rotary head type recording device according to claim 1, wherein the recording is performed at a stage subsequent to the high-efficiency encoding circuit. (3) Rotation of n pieces among (n×m) rotating heads (n is an integer of 1 or more, m is an integer of 2 or more) arranged close to each other from above the recording medium being conveyed at a predetermined speed. a first mode in which the signal is reproduced using only the head; and a first mode in which the recording medium is moved at a predetermined speed in a direction intersecting the rotating surface from the top of the recording medium, which is being transported at a speed m times that of the first mode. (n×
m) a second reproducing signal using all of the rotating heads;
A rotary head type playback device that has two modes. (4) The reproduced signal is a digital signal encoded with high efficiency, and the output in the first mode is performed from the latter stage of the decoding circuit that supports high efficiency encoding, and the output in the second mode is 3. The rotary head type reproducing apparatus according to claim 3, wherein the output is performed from a stage before the decoding circuit.