JP3036014B2 - Magnetic recording / reproducing device - Google Patents

Description

The present invention relates to a magnetic recording / reproducing apparatus, particularly, for example, a digital VTR.
The present invention relates to a digital magnetic recording / reproducing apparatus suitable for use in (VCR).

[Summary of the Invention]

According to the present invention, in a magnetic recording / reproducing apparatus, a magnetic head in which m head chips are arranged adjacent to each other in a set is provided on an n-set rotating drum, and a standard mode (NTSC system, PAL system, etc.) is provided. ), A switching means for selectively switching between the input of the video signal and the input of the video signal in the high-definition mode is provided. When the video signal in the standard mode is input, the n types of video signals are divided into m for each type, and these m divisions are performed. The synchronized video signals are respectively recorded simultaneously and sequentially on a recording tape.
The video signal is divided into (m × n) and the divided video signals are synchronized and recorded on a recording tape. And, in particular, when recording video signals in the standard mode, a plurality of video signals with different input sources can be recorded on one recording tape, thereby diversifying the use of digital VTRs. It is something that can be planned.

[Conventional technology]

Recently, a so-called digital VTR (VCR) has been developed which converts a video signal into a digital video signal and records and reproduces the data on a magnetic tape using a rotating head.

As shown in FIG. 6, a conventional digital VTR has a rotary drum (4) in which two heads (41a) and (41b) face 180 degrees.
2) The magnetic tape (43) is wound around the rotary drum (42) at a wrap angle of 180 degrees and travels, so that the heads (41a) and ( Recording tracks (44a) and (44b) are formed by 41b).

Conventionally, two heads (41
a) and (41b) are arranged side by side in close proximity to each other, and a digital VTR that simultaneously records and reproduces data for two channels in digital format.
Has also been proposed.

[Problems to be solved by the invention]

By the way, when considering a digital VTR that can record both standard mode (NTSC, PAL, etc.) video signals and high definition video signals, the difference in the amount of information to be recorded between the standard mode and the high definition mode is the compression ratio. Although it depends, it is considered to be about 2-3 times.

Now, assuming that the difference in information amount is doubled, when recording both using the same recording tape and rotating drum, when inputting a video signal in the Hi-Vision mode based on the standard mode, The recording density is halved to make the total recording time the same.

 The recording density is the same and the total recording time is halved.

There is a method that can be considered. Of these methods, the performance is degraded and has little meaning, and thus is promising.

In order to realize this method, a method has been considered in which the tape speed is doubled and the number of rotations of the rotating drum is also doubled. However, in the case of a digital VTR, the rotating drum operates at high speed even in the standard mode. It is difficult to use at twice the number of rotations corresponding to the HDTV mode, and it is impossible to record both the standard mode video signal and the HDTV mode video signal. .

In addition, when recording a video signal in a standard mode in a conventional digital VTR, only a video signal from one input source can be recorded, and there is a limit to diversification of usage modes in the digital VTR.

The present invention has been made in view of such a point, and an object thereof is to selectively record not only a standard mode video signal but also a high definition mode video signal on a recording tape. It is an object of the present invention to provide a magnetic recording / reproducing apparatus capable of recording a plurality of video signals having different input sources on a single recording tape when recording a video signal in a mode, and enabling diversification of use modes in a digital VTR. is there.

[Means for solving the problem]

In the magnetic recording / reproducing apparatus of the present invention, an n-set rotating drum (2) is provided with a magnetic head (1) in which m head chips (5) are arranged adjacent to each other for one set.
Selectively switching the switching means to the input of the video signal V _h input and HDTV modes of the standard mode video signal V _s (18)
When a standard mode video signal V _s is input, n types of video signals, for example, V _s1 and V _s2, are divided into m for each type, and these m-divided video signals, for example, (D ₁ , D ₂ ) and (D _3, D ₄₎ was respectively synchronizing and recorded in by entering a sequence corresponding magnetic head head chip recording tape (3), whereas, when the input video signal V _h of HD mode, the video The signal _Vh is divided into (m × n), and these divided video signals, for example, (D _{1 to} D ₄ ) are synchronized and then input to the corresponding m × n head chips for recording. It is configured to record on a tape (3).

[Action]

According to the configuration of the present invention described above, the rotating drum (2) has m
Pieces of the head chip (5) magnetic head which is disposed in parallel in close proximity to each other (1) with n sets provided, selectively input video signal V _h input and HDTV modes of the standard mode video signal V _s switching since the provided switching means (18), it is possible to record selectively recording tape a video signal V _s and HD-mode image signal V _h of the standard mode (3).

Further, when the input video signal V _s of the standard mode, since the n type of the video signal V _s1 and V _s2 to record periodically to the recording tape (3), a plurality of different video signals respectively input source
V _s1 and V _s2 can be recorded on one recording tape (3), which can promote the diversification of use modes in the digital VTR (A).

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a block diagram showing a configuration of a main part of a magnetic recording / reproducing apparatus according to the present embodiment, in particular, a digital VTR (A). FIG. 2 is a magnetic head used in the digital VTR (A). FIG. 3 is a plan view showing an example of a front view.

This digital VTR (A) has two sets of magnetic heads (1a)
And (1b) are provided on the rotating drum (2) at 180 degrees opposite to each other, and the magnetic tape (3) runs around the rotating drum (2) while being wound at a wrap angle of 180 degrees. .

The magnetic head (1a) or (1b) is shown in FIGS.
As shown in the figure, on the same head base (4a) or (4b), two head chips (5a) and (5b) [or (5c) and (5d)] are juxtaposed and juxtaposed. Become. In these figures, (6) indicates an insertion hole through which a screw for fixing the head base (4a) or (4b) to the rotating drum (2) is inserted. Also, two head chips (5a) and (5b) [or (5c) and (5d)]
Has a structure in which the vicinity of the gap g of the ferrite head (7) is cut obliquely and sendust is sputtered (sprayed), and each gap g is + θ, It is formed with an inclination of −θ.
Incidentally, (8) indicates glass, and (9) indicates a sendust sputtered film. In addition, a predetermined interval GL is provided between the gaps g in the head scanning direction so as to prevent the influence of crosstalk or the like.

The magnetic head (4a) or (4b) divides, for example, a video signal of one field into two and gives each signal to a head chip (5a) and (5b) [or (5c) and (5d)], respectively. It is possible to record two channels simultaneously. Of course, it is also possible to reproduce two channels simultaneously. In this case, the following head chip (5b)
It is preferable to select the step DA in the track pitch direction between the head chips (5a) and (5b) [or (5c) and (5d)] in consideration of the delay equivalent of [or (5d)].

Thus, in this example, the input stage includes one tuner (11) for the high-definition mode and two tuners (12) and (13) for the standard mode, and the tuners (11) and (12). and in response to (13), a frame memory the image signal V _h of HD mode is stored (14)
A frame memory for video signal V _s of the standard mode is stored (15) and (16) have, and each frame memory (15)
And a multiplexer for outputting a video signal V _s of the standard mode in (16) is converted to series to the subsequent signal processing system (1
And 7), comprising a changeover switch (18) for selectively switching the input of the video signal V _s of the input and the standard mode of the video signal V _h of HD mode.

Next, the operation of the digital VTR (A) according to the present example will be described.

Now, switching the direction indicated the switch (18) by a solid line, if you select the input video signal V _h of HD mode, in the video signal input via the antenna (19), high-definition mode of the video signal V _h tuner (11)
A / D converter after being tuned and taken out by (20)
In converts into a digital video signal V _hd, the synchronous separation circuit (21), a vertical synchronizing signal S _hv (the frame pulse) detects the horizontal sync signal S _hh, based on these synchronization signals S _hv and S _hh After the A / D conversion, the signal passed through the low-pass filter is subjected to blocking and compression processing in a processing circuit (14) for compression and the like, and is subjected to framing processing for recording in the next recording processing system (B). Then, it is sent to the changeover switch (18). In the above-described compression processing, in the case of the high-vision mode, for example, a signal of 864 Mbps (8-bit quantization) is compressed to 60 Mbps.

Data D _h of the fed to the recording processing system (B) 1 field of the first parity for error correction by the ECC encoder (22) is added is generated. This added one field data D _h parity is supplied to a channel coder (23), coding tailored to the characteristics of the tape head system or the like is performed. This coded one
Field of data D _h is supplied to the channel division circuit (24).

This channel division circuit (24), which incorporates a random access memory (M ₁₎ ~ (M _4), sequentially memory data D _h for one field supplied (M ₁₎ ~ (M ₄₎ It is written, and is adapted to 4 dividing the data D _h, the memory (M ₁₎ and (M ₂₎ from one field data D ₁ and D ₂ of the first half of the channel division circuit (24) Read sequentially, and then the _first data D ₁
Regard, by delaying the output timing of the data D ₁ of the said first through a delay circuit (25), as shown in FIG. 5, simultaneously the output timing of the data D ₁ and D _2.
Thereafter, respectively recording amplifier The synchronized data D ₁ and D ₂ (26a) and (26b), the recording and reproducing change-over switch (27
a) and (supplied 27b) through on a rotating drum (2) to the head chip (5a) and (5b), at the same time to record data D ₁ and D ₂ on the magnetic tape (3). Then, at the stage where the rotating drum (2) has a half turn, turn, sequentially reads out the memory (M ₃₎ and (M ₄₎ from 1 second half of the data D ₃ and D ₄ fields channel division circuit (24), Furthermore respect the head of the data D ₃ of which, by delaying the output timing of the head of the data D ₃ through a delay circuit (28),
As shown in FIG. 5, simultaneously the output timing of the data D ₃ and D _4. Thereafter, the synchronized been D ₃ and D ₄ respectively recording amplifier (26c) and (26 d), the recording and reproducing change-over switch (27c) and (27d) via a rotary drum (2) on the head chip (5c) and it is supplied to the (5d), at the same time records the data D ₃ and D ₄ on the magnetic tape (3). Recording state of the magnetic tape (3), as shown in FIG. 4, when the rotating drum (2) is rotated 1 is made an inclined azimuth recording state data D ₁ to D ₄ are parallel.

And by repeating the above series of operations sequentially,
Digital video signal V _h in the frame memory (14) is sequentially recorded in the magnetic tape (3) for each one field. If the data write timing and the read timing for the frame memory (14) are the same, only one frame memory (14) is required for the tuner (11).

Next, the case of reproduction, the reproduction processing system (C), first, and the data D ₁ of the the head chip (5a) and (5b)
D ₂ (the first half data of one field) is supplied to the reproduction amplifier (29a) through the recording / reproduction changeover switches (27a) and (27c), respectively.
And is supplied to the (29 b), the playback amplifier (29a) and (29 b) data D ₁ and D ₂ are respectively data and clock recovery circuit from (30a) and (30b), time base corrector (31a) and ( 31b) through the channel synthesis circuit (3
2) supplied to.

This channel synthesizing circuit (32) also has a random access memory (m ₁ ) to
(M ₄ ), and the data D ₁ and D ₂ are sequentially stored in the memories (m ₁ ) and (m ₂ ). Then, the head chip (5c)
And (the second half of data for one field) is respectively recorded PLAY switch data D ₃ and D ₄ from (5d) (27c) and (2
7d) is supplied to the reproduction amplifiers (29c) and (29d), and the data D ₃ from the reproduction amplifiers (29c) and (29d) are supplied.
And D ₄ are data and clock recovery circuits (30c) and (30d), and time base collectors (31c) and (31d), respectively.
Are stored in the memories (m ₃ ) and (m ₄ ) of the channel synthesis circuit (32). Then, the channel synthesis circuit (3
2) Data D _{1 to} D ₄ are sequentially read out from the memories (m ₁ ) to (m ₄ ) in series and converted into a one-field composite signal D _h shown in FIG. 5, and then the composite signal D _h is converted to a channel. A D / A converter (3) through a decoder (33), an ECC decoder (34), and a deframing and decompression circuit (both not shown).
By supplying the 5), is reproduced from the output terminal phi _out to restore the original video signal V _h.

Next, a recording and reproducing regarding the standard mode video signal V _s. In this case, by switching the changeover switch (18) in the direction shown by the broken line, the video signal in the standard mode is set.
V _s input is selected.

For example, of the video signals transmitted from each TV station by the NTSC system, for example, the tuners (12) and (13) use different types of video signals _Vs1 and _Vs1 from the two TV stations (that is, have different program contents). Select V _s2 .

Each tuner (12) and (13) respectively the video signal V _s1 and V _s2 of the standard mode from the A / D converter (36) and (3
In 7), the signals are converted into digital video signals V _sd1 and V _sd2 , and in each of the sync separation circuits (38) and (39), a vertical sync signal S _sv and a horizontal sync signal S _sh are detected.
Based on S _sv and S _sh , as in the case of the high-definition mode, blocking and compression processes are performed in the processing circuits (15) and (16) for compression, respectively, so that the amount of information after compression is in the high-definition mode. In this case, the information amount is one half of that in the case.
As an example, information of 216 Mbps (8-bit quantization) is 30M.
Compressed to bps. After this compression processing is performed, the data D _s1 and D _s2 for one field, which are different from each other, are converted into a series of composite data D _sc via a multiplexer (17), and the recording processing system (B) at the next stage To send to. The subsequent operation is the same as the operation for the video signal V _h of the high-definition mode, it will be described only main points, the head of the 1
Field data (data from one selected television station) D _s1 is divided into two (D ₁ , D ₂ ) by a channel dividing circuit (24), and is then synchronized to each of the head chips (5
recorded on magnetic tape (3) via a) and (5b),
Data for the next one field (data from the selected other TV station) _Ds2 is also the channel dividing circuit (24)
Are divided into two (D ₃ , D ₄ ), synchronized, and recorded on the magnetic tape (3) via the head chips (5c) and (5d) (see FIG. 5). Recording state of the magnetic tape (3), as shown in FIG. 4, the inclined azimuth recording state and made the data D ₁ to D ₄ are parallel, in this case, one of the data D ₁ and D ₂ are selected data of one field from the television station, the one field data from other television station data D ₃ and D ₄ are selected.

By repeating the above series of operations, the video signals _Vsd1 and _Vsd1 in each of the frame memories (15) and (16) are
_vd2 is recorded on the magnetic tape (3) alternately for each field.

 Next, a reproducing operation will be described.

First, when it is desired to reproduce the video signal _Vs1 from one selected television station, the recording and reproduction changeover switches (27a) to (2a)
Of 7d), the switch (27a) and (27b) only switching to the reproducing side, after taken out only the data D ₁ and D ₂ through the head chip (5a) and (5b), the data D ₁ and D ₂ are synthesized by a channel synthesis circuit (32), and further a channel decoder (33), an ECC decoder (34) and a D / A converter (3
5) to restore the video signal V _s1 from one TV station selected by the tuner (12) and output the signal φ _out
Take out more. On the other hand, when the user wants to reproduce the video signal _Vs2 from another TV station selected by the tuner (13), the switch (27) among the recording / reproduction changeover switches (27a) to (27d) is used.
Only c) and (27d) need to be switched to the reproduction side.

In this reproduction, two types of video signals _Vs1 and Vs1 are used.
_When performing so-called picture-in-picture processing for simultaneously reproducing and combining _s2 , all of the recording / reproduction changeover switches (27a) to (27d) are switched to the reproduction side, and each of the head chips (5a), (5b) and Data D ₁ to (5c) and (5d)
D ₄ is a series synthesized signal by the channel synthesis circuit (32)
It may be converted into _Dsc and supplied to a known picture-in-picture processing circuit (not shown) at the subsequent stage.

As described above, according to this example, two head chips (5
a) a magnetic head (1a) in which a) and (5b) are arranged close to each other, and two head chips (5c) and (5d)
Together but placed on the rotary drum (2) in close proximity to the magnetic head (1b) provided in parallel with 180 degrees opposite to each other, the video signal V _s of the input and the standard mode of the video signal V _h of HD mode
Since the input was set to selectively switch provided changeover switch (18) can be selectively recorded on the magnetic tape (3) the video signal V _h and the standard mode video signal V _s of HD mode. In particular, with respect to the video signal V _h of HD mode, for example, the standard mode of the video signal 2
When the information is compressed so as to have twice the amount of information, in this example, the two magnetic heads (1a) and (1b) are provided on the rotating drum (2). You can record the video signal V _h of HD mode on the magnetic tape (3) at the same rotational speed as when recording a video signal V _s of the standard mode.

Further, when the input video signal V _s of the standard mode, 2 kinds of magnetic tape a video signal V _s1 and V _s2 every field (3)
Are recorded alternately, so that two types of video signals V _s1 and V _s2 having different input sources respectively can be recorded on one magnetic tape (3).
In the digital VTR (A).

In the above embodiment, when the input of the normal mode video signal V _s, and to record alternately every field video signal V _s1 and V _s2 from two different television stations on one magnetic tape (3) However, in addition, video signals from two video cameras (such as security cameras) may be recorded on one magnetic tape (3), and the application range is very wide.

In the above embodiment, two sets of magnetic heads each having two head chips are provided on the rotating drum (2). However, in general, n sets of magnetic heads having m head chips are provided. was placed on the rotary drum (2), when recording a video signal V _h of HD mode, the video signal V _h at channel division circuit (24) (m × n)
After dividing, and recorded on the magnetic tape (3) via n magnetic head, when recording the video signal V _s of the standard mode, the channel dividing circuit different n types of video signals input source (24) May be divided into m and recorded on the magnetic tape (3) periodically via the corresponding magnetic heads.

〔The invention's effect〕

According to the magnetic recording / reproducing apparatus of the present invention, in addition to the standard mode video signal, a high-vision mode video signal can be selectively recorded on the recording tape without increasing the rotation speed of the magnetic head. When recording a video signal in the mode, a plurality of video signals having different input sources can be recorded on one recording tape, and the use modes in a magnetic recording / reproducing apparatus such as a digital VTR can be diversified.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of a digital VTR according to this embodiment, FIG. 2 is a front view of a main part showing a magnetic head of this embodiment, FIG. 3 is a plan view thereof, and FIG. FIG. 5 is an explanatory diagram showing a recording state on a magnetic tape according to the present embodiment, FIG. 5 is an explanatory diagram showing signal processing (synchronization) according to the present embodiment, FIG. 6 is a schematic configuration diagram showing a conventional example, and FIG. FIG. 4 is an explanatory diagram showing an example of a recording state. (A) is a digital VTR, (1a) and (1b) are magnetic heads, (2) is a rotating drum, (3) is a magnetic tape, (5a)
~ (5d) is the head chip, (11) ~ (13) is the tuner,
(18) is a changeover switch, (B) is a recording processing system, (C)
Is a reproduction processing system.

Claims (1)

(57) [Claims] 1. A magnetic head comprising m sets of head chips arranged side by side in close proximity to each other on a set of n sets of rotating drums, a standard mode video signal input and a high definition mode video signal. Switching means for selectively switching the input of the video signal. When a video signal in the standard mode is input, n types of video signals are divided into m types for each type, and after these m-divided video signals are respectively synchronized, The signals are sequentially input to the corresponding head chip of the magnetic head and recorded on a recording tape. When a video signal in the high-definition mode is input, the video signal is (mx
n) A magnetic recording / reproducing apparatus which divides a video signal, synchronizes the divided video signals, and inputs the divided video signals to corresponding ones of the m × n head chips to record on a recording tape.