JP2718768B2 - Magnetic recording and playback device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus capable of selectively recording input video signals in a plurality of signal formats.

[Conventional technology]

Rotary head helical scan video tape recorder (abbreviated as VTR), which is a home magnetic recording and playback device.
Until now, the standard television signal format was considered based on the NTSC format (PAL and SECAM in Europe). However, in recent years, an improved version of the standard TV signal format, EDTV (Exte
In addition to the practical use of the nded Definition TV (HDD) system, the development and commercialization of the HDTV (High Definition TV) system, which is a higher-quality, high-definition (also called high-definition) television system, is underway. This TDTV system and HD
Regarding TV-VTR, see Journal of the Institute of Television Engineers of Japan Vol.42, No.7
(1988), pp 655-658 "Special feature, Television Annual Report, 4-
2. HDTV (High Definition),
VT of various methods such as analog recording method and digital recording method
There is R. As specific examples of analog and digital high-quality VTRs, the Television Society Technical Report PPOE56-2, pp7-11 (published on November 28, 1984) for the former, and TV Journal of John Society Vol.42, N
o.4 (1988), pp338-pp346, "Special Issue, Recent Magnetic and Optical Recording Technologies, 5.1, Digital VTR". Each of these various high-definition VTRs is a magnetic recording and playback device dedicated to high-definition television signals.

[Problems to be solved by the invention]

That is, the above-mentioned conventional VTR does not consider recording / reproduction other than high-definition television signals, and does not have a conventional standard television signal recording / reproduction function, which is particularly demanded for home VTRs.

In addition, the EDTV system, which is a good version of the standard TV system, is currently being put into practical use, and it is cost-effective and space-efficient to prepare VTRs for each TV system as home VTRs. Is also inconvenient.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording / reproducing apparatus capable of recording and reproducing a plurality of signals of a plurality of television signal formats including reproduction or recording / reproduction of a conventional standard television signal by one apparatus.

[Means for solving the problem]

The above object is achieved by the following configuration. That is, in a rotating head helical scan type magnetic recording / reproducing apparatus having a rotating drum having a lead angle which forms an inclination angle of a recording pattern in a standard recording mode, at least both the drum rotating speed and the capstan rotating speed for running the magnetic tape are controlled. Both have a drum servo circuit and a capstan servo circuit for controlling rotation at 1 times and N times of the standard recording mode, and reproduce the magnetic tape recorded in the standard recording mode in the N times rotation state. And means for recording the input video signal on the magnetic tape in the N-fold rotation state.

An output video signal output from a means for reproducing the magnetic tape recorded in the standard recording mode in the N-fold rotation state is input to a means for recording on the magnetic tape in the N-times rotation state. The configuration is as follows.

[Action]

The type of the input video signal is determined manually or automatically, and according to the type, a drum servo circuit and a capstan servo circuit are set so that the number of rotations of the rotating drum and the magnetic tape speed are suitable for the signal band to be recorded. Switch. The combination of a plurality of heads mounted on the same drum is changed so that the azimuth angle of the recording pattern, the pattern width, and the number of tracks formed in one field period are desired. As described above, a recording pattern previously recorded in the standard recording mode can be easily reproduced in a compatible manner, and recording and reproduction of video signals in various signal formats such as an HDTV system can be performed by one magnetic recording / reproducing apparatus having one rotating drum. It becomes possible. Further, the magnetic tape recorded in the standard mode can be dubbed at high speed with minimum hardware by effectively utilizing the recording / reproducing means.

〔Example〕

Hereinafter, an embodiment of the magnetic recording / reproducing apparatus according to the present invention will be described as a first embodiment.
This will be described with reference to the block diagram in FIG.

In FIG. 1, reference numerals 1, 2, 3, and 4 denote rotating heads mounted on a rotating drum 5 for recording and reproducing video signals, 6 denotes a magnetic tape, 7 denotes a drum motor, 8 denotes a drum servo circuit, and 9 denotes a cap. Stun motor, 10 is a capstan servo circuit, 11 and 18 are frequency discriminators, 12 is a reference signal generator (referred to as STD) for standard TV signal format (NTSC format), 13 is for high-definition TV signal format Reference signal generators (denoted as HD), 14, 15, 21, 32 are changeover switches, 16,
22 is a phase comparator, 17, 23 are adders, 19, 20, and 31 are frequency dividers, 24 is a drum tack head for detecting the rotational phase of the rotating head, and 25 is a control signal for tracking. Control (referred to as CTL) head, 2
It switches for 6 switches the standard television signal a ₁ and high definition television signals a _2, the magnetic tape 6 the input signal of a _1, a ₂ is 27
A recording signal processing circuit (including both analog recording and digital recording) for processing into a form that can be recorded on a recording head; 28, a reproduction processing circuit for performing processing such as demodulation on a signal obtained from a rotary head; VTR according to operation of input unit 30 (including switching between standard and high-definition modes)
The controller mainly performs the system control described above, and is constituted by a microcomputer having a control program built therein (or may be constituted by random logic).

FIG. 2 shows a top view of the rotary drum 5 of FIG.
The figure shows a front view. In the embodiment shown in FIG. 1, among the four heads, 1 and 3 have an azimuth angle of + α, 2 and 4 have an azimuth angle of −α, and the head width is in a mode for recording a standard television signal (standard mode). It is assumed to be approximately の of the pitch Tp of the recording track formed on the tape.

Fig. 4 shows another VTR dedicated to the standard mode (eg VHS system)
Recording patterns 401, 402,.
The tilt angle θs of the recording pattern is 5 ゜ 58′9.9 ″ in the case of the VHS system, the azimuth angle α is 6 °,
One recording track is formed in one field period.

FIG. 5 shows the rotation angle of the rotating drum shown in FIGS. 2 and 3 (the lead angle set so that the recording pattern in the standard recording mode in the magnetic recording / reproducing apparatus shown in FIG. 1 has the inclination angle θs in FIG. 4). FIG. 5 is a diagram showing recording patterns 501, 502, 503, 504,... Formed in a high-quality recording mode using

FIG. 6 shows the head trajectory when the combination of a plurality (four) heads on the rotary drum 5 is changed from the case of the high-quality mode and the standard recording pattern shown in FIG. 4 is reproduced in the standard mode. FIG.

Next, the operation of one embodiment of the present invention will be described with reference to the block diagram of FIG. 1, the diagram of the rotating drum of FIG. 2, and FIG. 3, and the pattern diagrams of FIG. 4, FIG. 5, and FIG. . First, the operation in the high-quality recording mode will be described.

The input video signal a ₁ (standard NTSC signal) and a ₂ (high quality signal, MUSE format in this case) are selected by the operation input unit 30, the selection signal SH is output from the controller, and the changeover switch 26 is selected.
(Selection may be made automatically according to the type of signal). In FIG. 1, the standard signal (ST
The case where D) is selected is illustrated. In this case, since the high-quality recording mode is set, SH is set to "L", and the switch 26 is tilted downward and switches each unit to the high-quality mode.

In the recording mode, the recording / playback signal is sent from the controller.
RP is output as "H" and switches each part. When RP becomes “H”, the switches (25, 21) of the respective parts are tilted upward.

Since high-bandwidth recording is required in the high-quality mode, the drum servo circuit 8 and the capstan servo circuit 10 are switched by the signal SH, and the drum rotation speed and the tape running speed (corresponding to the capstan rotation speed) are both set to the standard recording mode ( SH is “H”)
Change to twice the speed. A combination of four heads mounted on the rotating drum 5 is used so that the recording pattern becomes as shown in FIG. That is, two-channel recording (multi-track recording) is performed simultaneously by heads 1 and 2 (azimuth is reversed), and then recording is performed by heads 3 and 4 to record one field, and this is repeated. In other words, 501 for head 1, 502 for head 2, and 3 for head
503 and the head 4 form the 504 recording tracks 7.

That is, in one field period, one recording track is formed in the standard mode, while M tracks (four in this example) are formed in the high-quality mode. The inclination angle θ at this time
_H (HD mode): Both drum rotation speed and tape running speed are 2
Because it is twice, it becomes the same as θs (STD mode).

The operation for changing the drum rotation speed to twice will be described below. In the drum servo circuit 8 shown in FIG. 1, a signal DFG representing the number of revolutions of the drum motor 7 is input to a frequency discriminator 11 and the output thereof is fed back to the drum motor through an adder 17 so as to keep the DFG constant. Is hanging. By changing the reference signal (not shown) for this discrimination by SH, the number of rotations of the drum is changed to twice that of the standard mode. On the other hand, the phase control loop is controlled by the phase comparator 16 so that the phase of the vertical synchronizing signal V in the input signal coincides with the phase of the drum tack signal, and the mode is the high quality mode (V is 60 Hz).
Rotate at pm. In the standard mode, V (V is 59.94 Hz) is frequency-divided by 1/2 by the frequency divider 31 and compared with DTP, and rotates at 1798 rpm.

Next, an operation for changing the tape running speed to twice will be described below. In the capstan servo circuit 10, a signal CFG representing the rotation speed of the capstan 9 is supplied to a frequency discriminator 18.
And its output is fed back to the capstan motor through the adder 23, and a speed control loop is applied to keep the CFG constant. By changing the reference signal (not shown) for this discrimination by SH, the capstan rotation speed (that is, the tape running speed) is changed to twice the standard mode. On the other hand, since the phase control loop is during recording, the signal obtained by dividing the CFG by 20 and the signal obtained by dividing the output REF of the reference signal generator (for HD, 60 Hz in this case) by 19 (when the frequency is not divided) ) Is controlled by the phase comparator 22 so that the phases coincide with each other. In the standard mode, the reference signal generator (for STD, here 29.97H
The output of z) is used as a reference of the phase comparator 22.

Next, the operation in the reproduction mode will be described. When the recording pattern in the high-quality mode shown in FIG. 5 is reproduced, the signal is changed to "L" by the controller, and in the drum servo circuit 8, the operation of the speed control loop is the same as that at the time of recording. , DTP and reference signal generator (for HD, 60H
z) operates so that the output and REF are in phase,
The rotating drum 5 rotates at twice the standard mode. On the other hand, in the capstan servo circuit, the signal obtained by dividing the CFG by 20 and the control signal recorded for tracking
The operation is performed so that the phases of the CTLs coincide with each other, and the tape 6 runs at twice the standard mode.

Next, a description will be given of how the apparatus shown in the block diagram of FIG. 1 enables reproduction in the standard mode by using the rotary heads 1 and 4 shown in FIGS. 2 and 3 in combination. Sixth
In the drawing, 401, 402,... Are recording patterns previously recorded in the standard mode. In FIG. 1, the controller for instructing the standard mode and the reproduction mode from the operation input 30 sets SH to “H”, RP
To “L” to switch the mode of each part. As a result, the running speed of the rotating drum 5 and the tape 6 becomes the value of the standard mode as described above, and the reproduction signal processing circuit 28 is also switched to the standard mode. The heads 1 and 4 are also selected, and as shown in FIG. 6, the track 401 is moved to the head 1 having an azimuth angle of + α.
Then, the track 402 is reproduced by the head 4 having an azimuth angle of -α, and this operation is repeated thereafter, so that the recording tape in the standard mode can be reproduced compatible with one VTR. Regarding the recording in the standard mode, there is a point that only half of the track pitch is recorded by recording with this combination of heads, but it is also possible to provide a recording function.

The above description has been made for the case where the speed of the rotary drum 5 and the tape 6 is twice as high as that in the standard mode. Is described below. FIG. 7 shows the scanning locus of the head in this case. 701 is a still (tape stationary) state, 702 is a standard mode (m = n = 1) state, 703 is a head trajectory in a high-quality mode (m and n times), and the operation angle of the recording pattern is θ. _{O 2} , θ _S and θ _H.

Assuming that one field period is V _S , the tape traveling speed in the standard mode is v _S , and the drum diameter is D, the distance (not necessarily one track length) traveled by the head during the V _S during still is 1 = m · πD / 2 …………………… (1) Using this l, And θ _H is a function of n / m. M = 2, n described above
= The angle of inclination of the case 2 Hoho to theta _S when the standard mode (V _S
Are slightly different).

Next, as a second embodiment, the head 1 shown in FIGS.
An example in which the azimuth angle of the heads 3 and 4 is + α and the azimuth angle of the heads 3 and 4 is −α will be described. FIG. 8 shows a recording pattern diagram recorded in the high-quality mode with this head configuration. Heads 1 and 2 form patterns 801 and 802, and heads 3 and 4 form patterns 803 and 804. In this case, compared to the case of FIG.
The same azimuth angle between 04 is disadvantageous in adjacent crosstalk. However, at the time of the standard mode, as shown in the pattern diagram of FIG.
There is an advantage that a complete VHS type recording pattern can be formed by regarding と and と as one head.
The same applies to the reproduction mode. That is, in the reproduction mode, the previously recorded pattern 901 is traced by the heads 1 and 2 at 903 and 904, and the recorded pattern 902 is
Trace at 5,906.

Next, as a third embodiment, FIG. 10 shows that the high-quality mode and the high-speed duplication (also called dubbing) of the tape recorded in the standard mode can be used according to the head configuration of the second embodiment. This will be described with reference to a pattern diagram. When the copy mode is instructed, in FIG. 10, each section is changed so that the magnetic tape 6 is twice (n = 2) and the rotating drum is twice (m = 2). This state is equivalent to the high-quality mode. By using two devices of FIG. 1,
The first unit reproduces the pattern recorded in advance in the standard mode shown in FIGS. 1001 and 1002 by the set of heads 1 and 2 and heads 3 and 4, and the second unit reproduces the pattern by the set of heads 2 and 3 and 4 By performing a recording operation, it is possible to duplicate in half the time of a normal operation. At this time, it is necessary to change the recording signal processing circuit 27 and the reproduction signal processing circuit. (The band cannot be doubled even if the number of rotations of the rotating drum is doubled with the device only in the standard mode). If the band is sufficient, the duplication can be performed not only twice but also N times (m = N, n = N).

Next, as an embodiment shown in FIG. 4, an example in which a crosstalk between adjacent tracks can be reduced in a high-quality mode and a complete VHS recording pattern can be formed in a standard mode will be described with reference to a top view of a rotary drum 5 'in FIG. This will be described with reference to the front view of FIG. The heads 1 ', 2', 3 ', 4' are the same as those described with reference to FIG. 5 and are used for the high quality mode.
Heads 1101 and 1102 for standard mode, azimuth angle 1101
+ Α, 1102 −α, head width 1101 and 1102 both VH
And substantially the same as the track pitch T _P of S type. With the combination of the above heads, the low frequency band of the crosstalk and the complete VHS pattern formation can be satisfied at the same time.

Next, as a fifth embodiment, the case where θ _H ≒ θ _S has been described above, but a case where θ _H and θ _S are different will be described with reference to the pattern diagram of FIG. Standard recording mode standard 1
Although VHS system has already been established is One, high quality recording mode standard is step being studied theta _H and theta _S
Do not necessarily have to match. As an example of non-coincidence, an example will be described in which the recording track width is halved in high-quality mode to enable long-time recording (here, double recording). For example Figure 11, with respect to the head on the rotary drum of Figure 12, the head 1 ', 2', 3 ', 4' the head width is set to 1/2 of the description so far (in T _P 1/4 Becomes). The drum rotation speed is twice (m = 2) the standard mode, and the tape running speed is the same as the standard mode (n = 1). The recording track at this time is
1103, 1104 ... (Head 1 'replaces 1103 with head 2'
1104 is formed simultaneously). The tilt angle θ of the recording pattern in this case
_H ′ is 5 ゜ 57′9 ″ according to equation (3), which is different from θ _{S. In} this example, the same recording time as in the standard mode can be secured even in the high-quality mode. Various combinations of the rotation speed of the rotating drum and the tape running speed are possible.

〔The invention's effect〕

As described above, according to the present invention, a single apparatus having the same rotating drum records and reproduces a plurality of types of television signals including reproduction or recording / reproduction of a magnetic tape recorded in a conventional standard mode. be able to. There is also an effect that a magnetic tape recorded in the standard mode can be dubbed at high speed with minimum hardware by effectively utilizing the recording / reproducing means in the high quality mode.

[Brief description of the drawings]

1 is a block diagram of a magnetic recording / reproducing apparatus according to an embodiment of the present invention, FIGS. 2 and 3 are external views of a rotating drum according to the present invention, FIG. 4 is a pattern diagram recorded in a standard mode,
5 and 6 are pattern diagrams for the high-quality mode and the standard mode, respectively. FIG. 7 is a diagram for explaining the inclination angle, and FIGS. 8 and 9 are pattern diagrams for explaining the second embodiment. , Tenth
FIG. 11 is a pattern diagram for explaining the embodiment of FIG.
FIG. 12 and FIG. 12 are external views of a drum for explaining the fourth embodiment, and FIG. 13 is a pattern diagram for explaining the fifth embodiment. 1, 2, 3, 4 ... head, 5 ... rotating drum, 8 ...
Drum servo circuit, 10 ... Capstan servo circuit, 29
……controller.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Atsushi Yoshioka 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Home Appliances Research Laboratory, Hitachi, Ltd. (72) Inventor Shuichi Matsuo 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Hitachi Inside Engineering Co., Ltd. (72) Inventor Tadashi Otsubo 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Home Appliance Research Laboratory, Hitachi, Ltd. (56) References JP-A-50-119612 (JP, A) JP-A-57-141005 (JP, A) JP-A-60-658 (JP, A)

Claims (2)

(57) [Claims] 1. A rotary head helical scan type magnetic recording / reproducing apparatus having a rotary drum having a lead angle which forms an inclination angle of a recording pattern in a standard recording mode, wherein at least the number of rotations of the drum and the capstan rotation for running a magnetic tape. A magnetic tape having a drum servo circuit and a capstan servo circuit for controlling both numbers to rotate at 1 times and N times of the standard recording mode, and a magnetic tape recorded in the standard recording mode in the N times rotation state Or a means for recording an input video signal on a magnetic tape in the N-fold rotation state, or both. 2. An output signal output from a means for reproducing a magnetic tape recorded in the standard recording mode in the N-times rotation state is input to means for recording on the magnetic tape in the N-times rotation state. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the apparatus is used as an input video signal.