JPH07118113B2 - Rotating head type recording device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head type recording device, and particularly 90 ° to each other.
The present invention relates to a device for recording a signal by winding a tape-shaped recording medium over an angular range of 270 ° or more around a cylinder member having four heads rotating with respective phase differences.

[Conventional technology]

This type of device has been used for the purpose of reducing the diameter of the rotary head cylinder of a VTR from the past.
The four heads rotating with a phase difference of ° are sequentially used to record a video signal of one field.

On the other hand, the applicant has already filed an application (Japanese Patent Application No. 61-
No. 147080), it is also possible to use a VTR having the above head configuration as a device capable of capturing and recording three times the number of screens as usual, and in this case, three of the four heads can be used simultaneously. Will be used for recording.

FIG. 7 shows an example of the arrangement of the magnetic heads of the above apparatus. The magnetic heads R and R'are rotary magnetic heads having the same azimuth angle, and the magnetic heads L and L'are rotary magnetic heads having the same azimuth angle. Also, magnetic heads R, L,
R ′ and L ′ have a relationship in which the rotational phases differ by 90 °,
Video signals of three systems are respectively input to three of the four magnetic heads R, L, R ', L', and tape guide posts 2, 3
Thus, the video signals of these three systems are recorded on the magnetic tape 4 wound around the rotary drum 1 over an angular range of 270 ° or more.

The relationship between the recording tracks recorded on the magnetic tape 4 and the respective magnetic heads is shown in FIG.

As shown in FIG. 8, when the magnetic head R is at the recording start timing, the magnetic head L'is at the recording end timing, and the magnetic head L is ahead of the magnetic head R by 90 °, so 1/3 field. Minute recording, magnetic head R'180 °
Since we are moving ahead, we are in a state where we have finished recording for 2/3 fields.

In this way, each magnetic head is in the order of R → L ′ → R ′ → L.
Recording will be performed every 1/3 field.

By the way, when reproducing the three-system video signals recorded as described above, it is also possible to simultaneously reproduce the three-system video signals by using three rotary heads that trace the recording medium at the same time as at the time of recording. However, the traveling speed of the magnetic tape 4 is set to 1/3 of that at the time of recording, and the four heads are used in the order of R → L → R ′ → L ′ → R. It is possible.

For example, when the video signals of the same image whose 1/3 field timings are mutually shifted are recorded as the above-mentioned three systems of video signals, if these are sequentially reproduced one field at a time, a fast moving image can be followed. Slow motion playback images can be obtained.

[Problems to be solved by the invention]

However, when trying to apply the well-known 4-frequency method as the tracking control method in the system as described above,
It is necessary to superimpose four types of pilot signals with different timings on the three systems of video signals, which results in an extremely complicated circuit configuration.

In addition, when recording the video signals related to the same image with the 1/3 field timing shifted as the three-system recording, and reproducing them one by one foot, on the magnetic tape, The arrangement of the pilot signal in (1) must be the same as that of a normal single-system recorded magnetic tape. Therefore, it is necessary to switch the order of pilot signals to be superimposed on a video signal between the case of performing simultaneous recording of three systems and the case of performing normal recording of one system, which further complicates the circuit configuration.

In view of the above-mentioned problems, the present invention provides a rotary head type recording device to which four frequency tracking control can be applied in a device capable of simultaneously recording signals of three systems with an extremely simple circuit configuration. The purpose is to

[Means for solving problems]

In order to achieve the above-mentioned object, in the present invention, a circuit bed type recording apparatus is configured as in (1) below.

(1) A device for recording a video signal by winding a tape-shaped recording medium over an angular range of 270 ° or more around a cylinder member having four heads that rotate with a phase difference of 90 ° from each other. Then, the four types of pilot signals for tracking control are associated with the four heads for recording these one-to-one, and the associated heads record the four types of pilot signals, respectively. In the first mode, one input video signal in one of the four heads is sequentially supplied, and in the second mode, three input video signals in the four heads are input. A rotary head type recording apparatus comprising: switching means for simultaneously supplying three switches; and means for switching the correspondence between the first mode and the second mode.

[Action]

With the configuration (1), the one-to-one correspondence between the four types of pilot signals for tracking control and the four heads for recording these is switched between the first mode and the second mode.

〔Example〕

 Hereinafter, one embodiment of the present invention will be described in detail.

FIG. 1 is a diagram showing a configuration of a main part of a VTR as an embodiment of the present invention, and FIG. 2 is a diagram showing a schematic configuration of the entire embodiment.

In FIG. 2, 5 is an image pickup lens, 6 is a half mirror positioned on the optical axis of the image pickup lens 5, 7 to 9 are image pickup circuits provided on the optical axis of the half mirror 6, and 10 is a vertical axis. A V driver 11 for generating a scanning signal is an H driver for generating a horizontal scanning signal, and outputs of the V driver 10 and the H driver 11 are sent to the image pickup circuits 7-9. 12 indicates the phase of the video signal output from the image pickup circuits 7-9.
A pulse generator that generates a pulse that shifts by 1/3 field, 13 is a synchronization signal generation circuit that gives a simultaneous signal to the three outputs, and 14 is a signal processing circuit that makes the three video signals into a signal form suitable for recording. The circuit 14 performs well-known processing such as FM-modulating the luminance signal and low-pass converting the chroma signal.

In the above configuration, the subject image that has passed through the image pickup lens 5 is transmitted / reflected by the half mirror 6, guided to the image pickup circuits 7 to 9, and converted into an electric signal. At that time, the V driver 10 and the H driver 11 receive a pulse generator 12 with a signal having a phase difference of 1/3 of one field on the magnetic tape.
V driver 10 and H driver 11 are each 1 /
Horizontal / vertical scanning signals shifted by 3 fields are given to the imaging circuits 7-9. The image pickup circuits 7 to 9 are supplied with the horizontal / vertical scanning signals in addition to the converted electric signals. The outputs obtained from the image pickup circuits 7 to 9 together with the sync signal obtained by the sync signal generation circuit are in the signal form suitable for recording as described above by the signal processing circuit 14 and the three video signals Si.
g.1, Sig.2, Sig.3 are obtained.

FIG. 5 is a diagram showing the three video signals Sig.1, Sig.2, Sig.3, and these are inputted as recording signals to the magnetic head through the switching circuit 15.

Reference numeral 21 denotes a 4-frequency signal generation circuit which will be described in detail later.
Four types of pilot signals related to frequency-based tracking control are output in parallel. These are mixers 22a, 22b, 22c, 22
At d, it is mixed with the recording signal of each magnetic head.

The switching timing of the head by the switching circuit 15 will be described below with reference to FIG.

At the time of three-system recording, as shown in FIG. 6 (a), when the video signal Sig.1 is input to the magnetic head R and recording is performed, the magnetic head R moves in the winding range of the magnetic tape. When the magnetic head L ′ reaches 90 °, which is ⅓ of 270 °, the magnetic head L ′ reaches the recording start point and starts recording the video signal Sig.2. Similarly, in the order of R ′ → L → R, the video signal Sig.3 → Sig.1 →
Sig.2 is also recorded on one track each. FIG. 8 shows the process of recording on the magnetic tape at this time.

When a recording command is issued by an operation unit (not shown) in FIG. 1, the system controller 17 receives this command and controls the switching circuit 15 according to the timing chart of FIG. Further, the capstan 20 is rotated at a predetermined rotation speed, the capstan drive circuit 23 is operated, and the magnetic tape 4 is run at a predetermined speed.

Next, the operation when the video signals are sequentially reproduced in the three systems will be described.

In this case, the magnetic head R traces the track on which Sig. 1 is recorded, and after the reproduced video signal of one field is obtained, the magnetic head L rotating 90 ° ahead of the magnetic head R rotates the signal Sig. Trace 2 recorded tracks. Then, tracing is performed in the order of R ′ → L ′ → R, and one field is reproduced in the order of Sig.1, Sig.2, Sig.3. At this time, the running speed of the tape 4 is 1/3 of that at the time of recording.

In FIG. 1, when an operation unit (not shown) commands the sequential reproduction of three video signals, the system controller 17
Controls the switching circuit 16 according to the timing chart of FIG. 6 (b), causes the capstan drive circuit 23 to rotate the capstan 20 at 1/3 of the rotation speed during recording, and the tape 4
The running speed of is set to 1/3 of the recording speed. Further, the capstan drive circuit 23 detects a tracking error by a known method using a pilot signal included in the output signal of the switching circuit 16, and performs tracking control in accordance with this. In this way, the switching circuit 16 outputs a high-speed video signal for one field at a time, and the reproduction signal processing circuit 18 converts the video signal back to a television signal form and then outputs it as a slow-motion reproduction image. Supplied to terminal 19. Next, a specific configuration of the above-mentioned 4-frequency signal generation circuit 21 will be described with reference to FIG.

24 is a selector switch for switching between 3 system recording and normal recording, 25
Is a multiplication circuit for multiplying the 45 HZ rectangular wave signal (45PG) synchronized with the rotation phase of the rotary drum by 2 times, 26 is the signal DATA input from the changeover switch 24, and the signal from the multiplication circuit 25 is the CLK input. D flip-flop, 27 is an oscillator, 28-31 are frequency dividing circuits for dividing the signals generated by the oscillator 27 and generating pilot signals f ₁ , f ₂ , f ₃ , f ₄ having different frequencies from each other, 32 Reference numeral 33 is a changeover switch as a changeover means for changing over the pilot signals f ₂ and f ₃ by the changeover signal from the D flip-flop 26.

In the above configuration, when the changeover switch 14 is on the normal recording side (L), the changeover signal is not output because the low level (L) signal is supplied to the DATA input of the D flip-flop 26. Therefore, the changeover switches 32 and 33 are connected to the L side. Then, pilot signals f ₁ , f ₂ , f ₃ . f ₄ is
Magnetic heads R, L, R ', L'via 22a-22d in FIG.
Entered in.

FIG. 3 is a diagram showing a timing chart for switching the magnetic head, and FIG. 4 is a diagram showing a pattern of recording tracks recorded on the magnetic tape. In FIGS. 3 and 4, a, b, n, o, and p indicate signals recorded during normal recording, and c to m indicate signals recorded during high speed recording.

Before the magnetic head L finishes recording, when the changeover switch 24 switches from normal recording to high speed recording, a high level signal is input to the DATA input of the D flip 26.
Then, the D flip-flop 26 does not change the output state until the signal from the multiplier circuit 25 as the next clock signal comes in, so that the switching signal is transmitted to the changeover switches 32 and 33 at the rising edge of the next clock signal. Along with this, the changeover switches 32 and 33 are switched from the normal recording side (L) to the three-system recording side (H).
The pilot signals f ₂ and f ₄
Will be supplied to L '. In time of three systems recorded after 1/3 field magnetic head R 'starts recording the pilot signal f ₃ is due to this, the recording magnetic head L is a pilot signal f _4, followed by the magnetic head R pilot signal f ₁ Is recorded, and high-speed recording is performed.

Next, when returning to normal recording from 3 system recording, changeover switch 24
To the normal side (L). Now, as shown in FIG. 3, when the above switching is performed before the magnetic head L finishes recording, the D flip-flop 26 returns the output signal to the low level at the next clock, and the changeover switches 32 and 33 are turned on. Activate.

Now, assuming that the switching operation of the switch 24 is performed during the recording of the pilot signal f _{4 by} the magnetic head L, the recording track m has an unrecorded portion for 1/3 field. The changeover switches 32 and 33 are switched from the (H) side to the (L) side. Then, the recording is resumed from the recording track n.

According to the VTR having the above-described structure, four kinds of pilot signals are recorded in a predetermined arrangement by the same circuit regardless of whether three systems of video signals are simultaneously recorded or one system of video signal is recorded. In addition, a circuit for sequentially switching the types of pilot signals and outputting the signals becomes unnecessary.

〔The invention's effect〕

As described above, according to the present invention, it is possible to perform tracking control of a four-frequency system in an apparatus that simultaneously records signals of three systems and records signals of one system with a simple circuit configuration. A possible rotary head recorder was obtained.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of essential parts of a VTR as an embodiment of the present invention, FIG. 2 is a diagram showing a schematic configuration of an entire VTR as an embodiment of the present invention, and FIG. A timing chart showing switching timings of the magnetic head in both modes of system recording, FIG. 4 is a diagram showing a recording pattern on the magnetic tape according to the present embodiment, and FIG. 5 is a timing chart showing recording signals of three systems. 6 (a) and 6 (b) are the switching circuit 1 in FIG.
5 and 16 are timing charts for explaining the operation, FIG. 7 is a diagram showing the arrangement of magnetic heads, and FIG. 8 is a diagram showing the state of tape traces on a magnetic tape that can be placed in simultaneous three-system recording. In the figure, R, L, R ′, L ′ are rotary heads, 22a, 22b, 22c, 22d are mixers, 27 is an oscillator, 28, 29, 30, 31 are frequency dividers, 32, 33.
Are changeover switches, respectively.

Claims (1)

[Claims] 1. A video signal is recorded by winding a tape-shaped recording medium over an angular range of 270 ° or more around a cylinder member having four heads that rotate with a phase difference of 90 ° from each other. A device, in which four types of pilot signals for tracking control are associated with the four heads for recording these in a one-to-one correspondence, and the associated heads respectively record the four types of pilot signals In the first mode, one input video signal is sequentially supplied to one of the four heads, and in the second mode, three input video signals are supplied to the four heads. A rotary head type, comprising: switching means for simultaneously supplying three of them, and means for switching the correspondence relationship between the first mode and the second mode. Recording device.