JPH0538401Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a signal recording and reproducing device such as a video tape recorder (VTR). In particular, the luminance signal and color difference signal that constitute the video signal, or
This invention relates to a device that separately records and reproduces signals of multiple channels, such as RGB signals, on a magnetic tape using a plurality of magnetic heads.

(Prior Art) Conventionally, in helical scan VTRs for broadcasting stations, luminance signals (hereinafter referred to as
A Y/C separated track component method is known in which a Y/C signal (hereinafter referred to as "Y signal") and a color difference signal (hereinafter referred to as "C signal") are recorded separately on different video tracks of a magnetic tape and reproduced.
Technical Report, Vol.31, No.6, Dec.1985,
(See p760-763).

In this type of VTR, a pair of magnetic heads 2 and 22 are integrally attached to a rotating cylinder via a mounting base 13, as shown in FIG. 3, and a Y signal is sent to one head 2, and a C signal is sent to the other head 22. A pair of tracks 3 on which a Y signal and a C signal are respectively recorded are placed on the signal surface of the magnetic tape 3 as shown in FIG. 5a.
1 and 32 are formed repeatedly.

(Problem to be solved) Generally, VTRs have multiple tape speed modes, and by changing the tape speed during signal recording, the recording time for the total length of the cassette tape can be adjusted. ing.

However, in a conventional Y/C separated track component system VTR, when the tape speed is reduced to extend the recording time, as shown in FIG.
32 and a pair of tracks 31a and 32a formed by heads 21 and 23 arranged 180 degrees apart from these heads 2 and 22 approach each other as the tape speed decreases, and the C signal is recorded by head 22. The Y by the head 21 is placed on the track 32 which has been
The signal track 31a is overwritten, thereby erasing part of the C signal. However, since the distance between heads 2 and 22 and the distance between heads 21 and 23 remain unchanged, Y
The signal is never canceled by the C signal.

As a result, a difference arises between the track width _V1 of the C signal and the track width _V2 of the Y signal, resulting in a problem of a difference in the reproduced outputs of both signals.

(Means for Solving the Problems) An object of the present invention is to provide a recording/reproducing apparatus in which output differences do not occur in reproduced signals from signal tracks of a plurality of channels even when the tape speed is changed.

The multi-channel signal recording/reproducing device according to the present invention has a rotating cylinder equipped with a plurality of head devices at predetermined angular intervals, which are switched and used according to a plurality of tape speed modes set during signal recording/reproduction. It is.

Each head assembly includes a plurality of magnetic heads disposed in close proximity to each other at predetermined relative positions.
The gap dimensions of these magnetic heads and the relative positions between the heads are determined according to the tape speed mode in which recording and reproducing operations are to be performed. The gap width and the head spacing are made larger than those for the low speed mode so that the width signal track is formed at a large pitch.

(Function) When recording a signal, a specific head device operates according to the set tape speed mode, and the signal side of the magnetic tape is displayed according to the gap size of the plurality of magnetic heads installed in the head device. A signal track having a track width determined is repeatedly formed at a track pitch depending on the current tape speed and relative position between the heads.

That is, in high-speed mode, the head device has magnetic heads with large gap widths arranged at wide intervals.
As shown in FIG. 5a, signal tracks 31, 32 with a large width _W1 are formed with a large pitch _P1 . On the other hand, in low-speed mode, the fifth
As shown in Figure b, a signal track 33 with a small width _W2 ,
34 is formed with a small pitch _P2 .

During signal reproduction, the head device used for signal recording operates, and each signal track is reproduced by a predetermined magnetic head having the same track width and track pitch.

(Effects of the invention) In the recording and reproducing apparatus of the invention, signal tracks with a smaller track width are formed at smaller pitches as the tape speed decreases during signal recording, so the weight between the tracks is reduced. Therefore, during signal reproduction, there is no output difference between the reproduced signals of each track.

(Example) Figures 1 to 3 show a recording/reproducing apparatus according to the present invention of a Y/C separated track component type.
An example of this applied to a VCR is shown.

The VTR cylinder 1 includes an upper cylinder 11 that is rotatably driven by a motor above a lower cylinder 12, and the upper cylinder 11 is connected to first Y heads 2, 21 and a second Y head for recording Y signals. 24, 25, the first C head 22, 23 and the second C head 26, which are to record the C signal.
27 are installed at the angular intervals shown in FIG.
A pair of magnetic heads (for example, the first Y heads 2 and 21) are arranged opposite to each other at an angular interval of 180 degrees.
Similar to the conventional device, this device forms a pair of video tracks that constitute a video signal for one frame.

Furthermore, each of the four sets of magnetic heads arranged at angular intervals of 90 degrees from each other is fixed to a common mounting base 13 at a predetermined relative position in close proximity to each other, as shown in FIG. This is what I did. A pair of magnetic heads (for example, the first Y head 2 and the first C head 22) arranged on the same mounting base 13 are
They are formed at different azimuth angles.

1st Y head 2, 21 and 1st C head 22, 2
3 is a first head device for high-speed mode that records and plays at the normal tape speed.The second Y heads 24, 25 and the second C heads 26, 27 record and play at half the normal tape speed. This constitutes a second head device for a low speed mode in which this is performed.

As shown in Figure 1, the
The shapes of the 1Y head 2 and the 1st C head 22 are different from the shapes of the 2nd Y head 24 and the 2nd C head ₂₆ which operate in the low speed mode. larger than the width W ₂ of the magnetic gap part, and
The step P ₁ between the heads 24 and 26 is larger than the step P ₂ between the heads 24 and 26 by a predetermined dimension.

As a result, in _the high speed mode, as shown _in FIG. It is repeatedly formed with a large pitch _P1 . With this, A track 3
A luminance signal is recorded on track 1, and a C signal is recorded on track 32, so that a guard band with no signal is formed between the tracks.

In addition, in the low speed mode, as shown in _FIG .
A B track 34 of W ₂ is repeatedly formed with a small pitch P ₂ . With this, A track 3
The Y signal is recorded on track 34, and the C signal is recorded on track B, and there is no guard band between the tracks.

FIG. 4 shows a recording/reproducing circuit to be connected to each of the magnetic heads.

Each magnetic head 2, 21 to 26, 27 has first and second changeover switches 7, 71 to 76, 77, respectively.
Recording amplifiers 5, 52, 54, and 56 and a pair of reproduction amplifiers 51, 53, 55, and 57 are connected through the amplifiers.

The Y signal and C signal to be recorded are connected to recording amplifiers 5, 52, 54, and 56 through the FM modulation circuits 4, 41 and selection switches 8, 81, respectively, and the output of each recording amplifier is connected to each of the aforementioned changeover switches. It is supplied to each magnetic head via.

Furthermore, the reproduction signals obtained from the pair of reproduction amplifiers are converted into frame signals through switching circuits 6, 61, 62, and 63, respectively, and are further converted into frame signals by a selection switch 8.
2, 83 and FM demodulation circuits 42, 43, Y
The signal and the C signal are reproduced.

The changeover switch, selection switch, and changeover circuit are controlled by a system controller (not shown).

As shown in FIG. 5a, when recording signals in the high-speed mode, the selection switches 8 and 81 are switched to the a side, and the Y signals are recorded by the first Y heads 2 and 21, and the Y signals are transferred to the first C heads 22 and 23. Therefore, the C signal is recorded. Further, as shown in FIG. 5b, when recording signals in the low speed mode, the selection switches 8 and 81 are switched to the b side, the Y signal is recorded by the second Y heads 24 and 25, and the Y signal is recorded by the second C head 26. ,27 by C
Record the signal.

Furthermore, in this embodiment, it is possible to monitor and reproduce the recorded signal by the second Y heads 24, 25 and the second C heads 26, 27 during signal recording in the high speed mode. In this case, selection switch 8,
81 to side a, and select switch 8
Switch 2 and 83 to the b side and record the signal at the same time.
2nd Y head 24, 25 and 2nd C head 26, 2
7, the recorded signal is reproduced.

As a result, as shown in FIG. 5c, the second Y head 24 and the second C head 26 straddle the A track 31 and B track 32 formed by the first Y head 2 and the first C head 22, and move on both tracks. Tracking is performed to reproduce the Y signal and C signal, respectively. At this time, the reproduced trace pattern 35,
36 is shifted from the recording tracks 31 and 32 as shown in the figure, so the reproduction output is lowered and the image quality is degraded to some extent, but this does not pose a practical problem on the monitor screen.

Note that the configuration of each part of the present invention is not limited to the above embodiments.
Of course, various modifications are possible within the technical scope of the claims for utility model registration.

For example, a multi-channel signal may include a Y signal and a C signal.
In addition to signals, signals of other configurations such as RGB signals may be used. In this case, each head device is equipped with a number of magnetic heads corresponding to the number of channels.

Furthermore, if three or more head devices are installed, it is possible to implement the present invention in a VTR having three or more types of speed modes.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the structure of a magnetic head installed in a recording/reproducing apparatus according to the present invention and how it is attached to a VTR cylinder, and FIG. 2 is a plan view showing the positional relationship of the magnetic head in a VTR cylinder. Figure 3 is a perspective view of a pair of magnetic heads fixed to a mounting base, Figure 4 is a block diagram of a signal recording/reproducing circuit, Figure 5 is a diagram showing various track patterns of magnetic tape, and Figure 6 is a conventional device. FIG. 1... VTR cylinder, 2, 21... 1st Y head, 22, 23... 1st C head, 24, 25
...2nd Y head, 26, 27...2nd C head.

Claims (1)

[Scope of utility model registration request] A plurality of magnetic heads are attached at predetermined relative positions to a rotating cylinder on which a magnetic tape is to be wound, and the magnetic tape is helically scanned by the magnetic heads to record signals of a plurality of channels on different tracks of the magnetic tape. Alternatively, in a playback device, a plurality of head devices are arranged at predetermined angular intervals on a rotating cylinder and are used by switching according to a plurality of tape speed modes set during signal recording and playback. , comprising a plurality of magnetic heads disposed close to each other at predetermined relative positions, the dimensions of the gap portions of the magnetic heads and the relative positions between the heads are defined according to the tape speed mode in which the recording/reproducing operation is to be performed. A multi-channel signal recording/reproducing apparatus characterized in that a high-speed mode head device has a larger gap width and head spacing than a low-speed mode head device.