JPH0440610A - dubbing system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a dubbing system, and in particular, a dubbing system in which a number of tracks are formed, each recording a predetermined period of information signals, and adjacent tracks having different azimuth angles. The present invention relates to a dubbing system for tape-shaped recording media.

[Prior Art] As mentioned above, there is a home-use helical scan video tape recorder (VTR) as a device for recording and reproducing information signals for a predetermined period on each track of a tape-shaped recording medium. A dubbing system using a type of VTR will be explained.

Generally, a so-called rotating two-head helical scan type VTR is known as a home VTR. Figure 6 (A), (B
) is a diagram showing a general head arrangement of this type of VTR. In FIGS. 6(A) and (B), 1 is a magnetic tape, 2
Reference numerals a and 2b designate tape guides for winding the tape 1 around the outer periphery of the rotating drum 3 over an angular range of 180 inches or more.

These are rotating heads that are attached to the rotating drum 3 with a phase difference of 180° from each other, and as shown in the figure (they are attached at the same height in the rotation axis direction and have different azimuth angles.Head HA .

As is well known, the HB records and reproduces one field's worth of video signals during a 180° rotation.

In this type of VTR, the length of the track on which the video signal for one field is recorded is predetermined in the standard. Therefore, the diameter of the rotating drum 3 is inevitably determined accordingly. Therefore, the diameter of the drum 3 cannot be reduced, which hinders the miniaturization of VTRs.

Therefore, the following VTRs have been proposed in the past as VTRs that can reduce the diameter of the drum.
FIG. In the figure, Ha and Hb are rotary heads having different azimuth angles, and rotate once during one field period of the video signal. Rotating head Ha,
Hb are marked as rotating close to each other with a phase difference of a minute angle θ°, and as shown in the figure (they are mounted at the same height in the direction of the rotation axis).

The tape 1 is wound around the drum 3 over an angular range of 300° or more, and is wound around the rotating head Ha.

Each Hb records one field's worth of video signals during 300 rotations. That is, the video signal for one field is recorded in a period shorter than the original period of one field of the video signal.

Therefore, the video signal recorded by this type of VTR is N.
When assuming a TSC signal, instead of a normal NTSC signal, that is, a signal with a vertical scanning frequency (fv) of 60 Hz and a horizontal scanning frequency (fh) of 15.75 kHz, an fv of 6
0Hz, fh is 18.9 (15,75X615)kHz
Must be of.

In other words, the video signal recorded by this type of VTR must be a normal television signal compressed in time axis to 5/6 in units of one field, or a signal obtained from a dedicated video camera.

The dedicated video camera mentioned above scans a screen with an aspect ratio of 9:1O (indicated by the dotted line Y in Figure 8), and uses the screen with an aspect ratio of 3:4 as shown by the solid line X in Figure 8 as the effective screen. It is output within the 5/6 field period. The above-mentioned FIG. 7(A).

Since the heads Ha and Hb shown in (B) can form one track within a 5/6 field period, it is possible to record one field of video signal to one track, and the sixth
It is possible to record video signals in a format similar to that of a VTR with the head arrangement shown in FIGS. (A) and (B). That is,
If a video signal is recorded as described above using a VTR with a head arrangement as shown in FIG. 7, the drum diameter can be reduced to 315 mm compared to a VTR with a head arrangement as shown in FIG.

Furthermore, if the reproduced video signal is time-extended by 615 times per field, the VTR having the head arrangement shown in FIG. 7 can perform the same operation as the VTR having the head arrangement shown in FIG. 6.

[Problems to be Solved by the Invention] Generally, when dubbing a tape using two VTRs, for example, when dubbing two hours of video information, it takes two hours to transfer the standard television signal. Real-time dubbing is common.

Now that camera-integrated VTRs are becoming more popular, and many people want simple editing and dubbing, it is extremely troublesome for users who are familiar with high-speed dubbing with tape recorders to perform such real-time dubbing. . for example,
It takes a lot of time and effort to delete just a small part of a two-hour video.

Furthermore, a VT using a small drum as shown in FIG.
When dubbing is performed in R, a video signal that has been time-axis compressed to 5/6 in units of one field is first time-axis expanded to form a standard television signal, and then
This requires various processing such as time axis compression for each field, making it extremely difficult to realize high-speed dubbing.

In view of the above-mentioned background, the present invention is small-sized, and
The purpose of this invention is to enable high-speed dubbing using a rotating head type device with a simple configuration.

[Means for Solving the Problems] According to the present invention, a tape-like recording is provided in which a large number of tracks are formed, each of which records information signals for a predetermined period, and adjacent tracks have different azimuth angles. In a dubbing system for duplicating a medium, a first drum has N rotating heads (N is an integer of 2 or more) that rotate closely and have different azimuth angles between adjacent heads. A tape-shaped recording medium is guided, and information signals on N adjacent tracks on the first tape-shaped recording medium are transferred using the N rotating heads.
A reproducing device that reproduces a channel signal, and a drum having N rotary heads that rotate closely and have different azimuth angles between adjacent heads.
A second tape-shaped recording medium is guided, and the reproduced N-channel signals are transferred to the second tape-shaped recording medium using the N rotary heads.
a recording device that records while forming N adjacent tracks on a tape-shaped recording medium, and the guiding direction of the first tape-shaped recording medium by the first drum is set according to the direction in which the first tape-shaped recording medium is guided. When the recording medium travels by N tracks in the predetermined period, the scanning direction of the N rotary heads is made to coincide with the longitudinal direction of the plurality of tracks, and the second tape-shaped recording medium is scanned by the second drum. The guiding direction was the same as that of the first drum.

[Operation] As described above, by guiding the tape-shaped recording medium on the recording device side and the playback device side, N rotary heads having different azimuth angles and rotating in close proximity can be used for a predetermined period of time. It became possible to record and reproduce signals on N tracks at a time. As a result, with an extremely simple configuration,
Dubbing of tape-shaped recording media in which a large number of tracks with different azimuth angles are formed between adjacent tracks without increasing the rotational speed of the rotating head or increasing the diameter of the drum holding the rotating head. It has now become possible to perform the process N times faster.

[Example] Hereinafter, a dubbing system according to an example of the present invention will be described in detail.

FIGS. 1(A) and (B) are diagrams for explaining tape guidance in a dubbing device as an embodiment of the present invention, and FIG. 2 shows a schematic configuration of a dubbing device as an embodiment of the present invention. FIG. 3 is a diagram showing the head configuration of the apparatus shown in FIG. 2.

The head configuration on the playback side and the recording side in the apparatus of this embodiment is different from the head configuration shown in FIGS.
P), and the direction of rotation of the head relative to the tape is different, as will be described later.

In FIG. 2, 40 and 41 are magnetic tapes whose recording format is the same as that of the VTR having the head configuration shown in FIG. 6 described above.

The operation of the dubbing device shown in FIG. 2 will be explained below. The servo circuit 17 controls the capstan motor 42, and the capstan C transports the tape 40 by two tracks per 1 field period. Further, the servo circuit 17 controls the drum motor 43 so that the drum D rotates once per field period. As a result, the playback heads Ha and Hb each trace the tape 40 every other track.

Here, the tape guide of the drum D in the apparatus of this embodiment will be explained using FIGS. 1(A) and 1(B).

In FIG. 1(A). υ7 is tape 4 during normal playback
It is a vector corresponding to the travel of 0, and its dimension. . is shown in Figure 7 (
Vectors corresponding to the rotations of the playback heads Ha and Hb in the conventional VTR with the head arrangements shown in A) and (B),
That is, it is a vector corresponding to the tape guiding direction of the drum. Also, size.

is the resultant vector of these, that is, the head trace direction (
This is a vector corresponding to the direction of the track.

On the other hand, in this embodiment, since the tape is run for two tracks per field period, the vector corresponding to the run of the tape 40 is 2 inches a, and if the tape is guided in the conventional direction, the resultant vector is is the size. Therefore, each track cannot be traced accurately.

Therefore, in this embodiment, the tape guiding direction is shown in Fig. 1 (A).
Let the direction of υ be the direction of the resultant vector, that is, the direction of the trace of the head. match.

That is, the angle formed by the tracing direction of the rotary head of the conventional VTR with the head arrangement shown in FIGS. 7(A) and 7(B) and the guide body (lead) of the drum is θ as shown in FIG. 1(A).
. When the paper is closed, the angle of this embodiment is θ as shown in FIGS. 1(A) and 1(B).

In FIG. 1(B), D is the drum D shown in FIG. 2, 91 is a rotating upper drum portion having heads Ha and Hb on its outer circumferential portion, and 92 is a fixed lower drum portion having a tape guide 93. It is. Further, in FIG. 1(B), TU indicates the upper end of the tape, and TL indicates the lower end of the tape. As a result, the heads Ha to Hb trace in a direction parallel to the tracks, and the tracks Ta and Tb are accurately traced by the tracking control described above.

FIG. 4 is a timing chart for explaining the operation of each part of the dubbing apparatus of this embodiment. In the figure, A+, B
1. A2 . . . indicates a video signal for l fields. Originally, in the VTR in the dubbing system of this embodiment, the video signal as shown in FIG.
, the reproduced signals from head Hb are as shown in FIGS. 4(c) and 4(d).

Incidentally, in the VTR having the head arrangement shown in FIG. 7 described above, a reproduced signal as shown in FIG. 4(b) can be obtained.

FIG. 5 is a diagram for explaining signals reproduced by the apparatus of this embodiment. FIG. 5(a) shows the spectral arrangement of signals recorded and reproduced by the VTR with the head arrangement shown in FIG. 6, and FIG.
R indicates the spectrum arrangement of the signals reproduced by the heads Ha and Hb. In the figure, Y indicates an FM modulated luminance signal, A indicates an FM modulated audio signal, and C indicates a low frequency converted chroma signal.As is clear from FIG. 5, in this embodiment, the head H
The frequency of the signals reproduced by a and Hb is 1.2 times that of the reproduced signal of the VTR with the head arrangement shown in FIG. It is 1.2 times that of .

Only the reproduced signal of the head Ha is supplied to the reproduced video signal processing circuit 12, and the processing circuit 12 converts the FM modulated luminance signal in the reproduced signal of the head Ha to a reproduced luminance signal obtained by FM demodulation and converts it into a low frequency signal. A reproduced video signal obtained by mixing the reproduced chroma signal obtained by frequency converting the chroma signal to the original band is compressed. The synchronization separation circuit 16 separates the synchronization signal from this reproduced video signal and supplies it to the servo circuit 17, which is used as a reference signal for controlling the drum motor 43 and the cab stan motor 42 as described above.

The servo circuit 17 controls the capstan motor 42 so that the output amplitude of the switch 11 is maximized so that the heads Ha and Hb can faithfully trace each track.

This tracking is well known and is not directly related to the present invention, so a detailed explanation will be omitted.

Since this reproduced video signal is a signal in which the signal of each field is time-axis compressed to 5/6, the signal of each field is compressed to 5/6 in the time-axis expansion circuit 13 in order to be supplied to an external monitor, etc.
15 on the time axis and output from the terminal 14.

Note that since the audio signal is not directly related to the present invention, a description thereof will be omitted in this specification.

On the other hand, the head configuration of the recording drum D° and the guiding direction of the tape 41 are the same as those of the reproducing drum D. Incidentally, for the sake of distinction, the rotary head provided on the recording side drum D° will be referred to as Ha'Hb'.

The servo circuit 26 controls the capstan motor 44 so that the capstan C° transports the tape 41 one track per field period, and controls the drum motor 45 so that the drum D° rotates once per field period. do.

The signals supplied to the heads Ha' and Hb' are the signals shown in FIGS. 4(c) and 4(d) via recording amplifiers 47a and 47b. Here, the heads Ha and Hb' are shifted from each other by one track pitch in the direction of the rotation axis, and the head Ha'
traces the tape 41 slightly ahead of the head Hb'. As a result, two tracks are simultaneously formed by the heads Ha and Hb' for each field period, and as a result, recording similar to that of a VTR whose head arrangement is shown in FIGS. 6 and 7 becomes possible.

Since the tape guiding direction of drum D' is the same as that of drum D, heads Ha' and Hb' are
The tape 41 is traced in the same direction as in normal recording in a conventional VTR having the head configuration shown in the figure, and video signals for two fields are simultaneously recorded on adjacent tracks having different azimuth angles. This operation is performed every one field period. This realizes dubbing at twice the speed of normal recording and reproducing operations.

According to the dubbing device of the embodiment described above, by using a VTR with a small drum diameter, without increasing the number of heads, and by simply adding a simple circuit such as an amplifier, it is possible to perform operations at twice the normal speed. High-speed dubbing is now possible.

In the above embodiment, the number of heads rotating close to each other is defined as two, but it is generally determined that the number of heads is N depending on the desired dubbing speed.
(N is an integer of 2 or more). however,
When dubbing is performed using a head arrangement as in the above embodiment, assuming a format that performs azimuth recording, the number of heads must be an even number.

In addition, in this specification, the dubbing system was constructed assuming a VTR using a small drum, but the present invention can be applied to any rotary head type information recording/reproducing device such as a DAT (digital audio recorder). Therefore, the embodiments can be modified as appropriate within the scope of the claims.

[Effects of the Invention] As explained above, according to the dubbing system of the present invention, it is possible to realize high-speed dubbing using a rotating head type device that is small and has a simple configuration.

[Brief explanation of drawings]

FIGS. 1(A) and (B) are diagrams for explaining the guidance of a tape that enters a dubbing device as an embodiment of the present invention, and FIG. 2 is a schematic diagram of a dubbing device as an embodiment of the present invention. Figure 3 shows the arrangement of the heads in the apparatus shown in Figures 1 and 2; Figure 4 shows the signal processing timing of each part in the apparatus shown in Figures 1 and 2. FIG. 5 is a diagram for explaining the video signals handled by the systems shown in FIGS. 1 and 2. FIGS. 6 (A) and (B) are conventional general VTR head arrangements. Figures 7 (A) and (B) show conventional VT using a small drum.
FIG. 8 is a diagram for explaining a video camera used exclusively in a VTR whose head arrangement is shown in FIG. 7. In the figure, Ha, Hb, Ha', Hb' are rotating heads, c, c' are capstans, D, D' are drums, 17.26 are servo circuits, 18.19 are 1
Field delay circuit, 42° 40.41 are magnetic tapes, 43.45 are drum motors, 47a and 47b are recording amplifiers, 91 is a rotating upper drum section, 92 is a fixed lower drum section, 93 is a tape guide body, θ is the tape guide angle. Figure 1 (A) Figure 1 (B) Figure 3 θ0 Men's shoes (B) t80' No. 7riJ /A) Figure 8

Claims (2)

[Claims] (1) A dubbing system that duplicates a tape-shaped recording medium in which a large number of tracks are formed, each recording an information signal for a predetermined period of time, and the azimuth angles of adjacent tracks are different from each other. The angles are different,
The first tape-shaped recording medium is guided by a first drum having N rotating heads (N is an integer of 2 or more) that rotate closely, and the first tape-shaped recording medium is guided using the N rotating heads. 1
A reproducing device that reproduces information signals on N adjacent tracks on a tape-shaped recording medium as N-channel signals; and N rotating heads in which adjacent heads have different azimuth angles and rotate closely By a drum with a head,
A second tape-shaped recording medium is guided, and the reproduced N-channel signals are transferred to the second tape-shaped recording medium using the N rotary heads.
a recording device that records while forming N adjacent tracks on a tape-shaped recording medium, and the guiding direction of the first tape-shaped recording medium by the first drum is set according to the direction in which the first tape-shaped recording medium is guided. When the recording medium travels by N tracks in the predetermined period, the scanning direction of the N rotary heads is made to coincide with the longitudinal direction of the plurality of tracks, and the second tape-shaped recording medium is scanned by the second drum. A dubbing system characterized in that the guiding direction is the same as that of the first drum. (2) In the reproducing apparatus, the N rotary heads reproduce the information signals on the N tracks in a specific period shorter than the predetermined period, and in the recording apparatus, the N rotary heads reproduce the information signals on the N tracks in a specific period shorter than the predetermined period.
The N rotary heads rotate the N rotary heads in a period shorter than the specific period.
The dubbing system according to claim 1, wherein the dubbing system forms two tracks.