JPH0440608A - Dubbing system - Google Patents

Abstract

PURPOSE:To attain rapid dubbing by inputting only video signals in one channel out of video signals in plural channels, and monitoring a dubbing signal. CONSTITUTION:A video signals reproduced at a double speed and outputted from a reproducing signal processing circuit 12 is supplied to the A terminal of a switch 22 through terminals 15c, 21c. At the time of dubbing, the switch 22 is connected to the A terminal by a system controller 37 and a recording video signal processing circuit 23 is interrupted from heads Ha', Hb'. Thereby a video signal supplied to the A terminal of the switch 22 is supplied to an overscanning monitor 49 and a time axis extension circuit 16, the dubbing state is monitored by a monitor 49 and supplied form a terminal 17 as a normal video signal. Consequently, rapid dubbing at twice the normal speed can be attained.

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 VTR will be explained.

Generally, a so-called rotating two-head helical scan type VTR is known as a home VTR. Figure 7 (A), (B)
1 is a diagram showing a general head arrangement of this type of VTR. In FIGS. 7(A) and (B), 1 is a magnetic tape, 2a
-, 2b are tape guides for winding the tape 1 around the outer periphery of the rotary tram 3 over an angular range of 180 inches or more.

Rotating heads are attached to the rotating tram 3 with a phase difference of 180° from each other, and as shown, they are attached at the same height in the direction of the rotating shaft 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 rotary tram 3 is inevitably determined accordingly. Therefore, the diameter of this tram 3 cannot be reduced, which hinders the miniaturization of VTRs.

Therefore, the following VTRs have been proposed as VTRs that can reduce the diameter of the tram. Figures 8 (A) and (B) show a conventional VTR using a small diameter tram.
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,
The Hb's are arranged to rotate close to each other with a small phase difference of θ°, and are mounted at the same height in the rotational axis direction as shown in the figure.

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

Each Hb records a video signal for one field while rotating by 300°. 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, when assuming an NTSC signal as the video signal described in this type of VTR, it is not 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. , fv is 60Hz, fh is 18.9 (15,75x615) kHz
It must be from z.

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 above-mentioned dedicated video camera scans a screen with an aspect ratio of 9:10 (indicated by the dotted line Y in Figure 9), and uses the screen with an aspect ratio of 3:4 (indicated by the solid line X in Figure 9) as the effective screen. It is output within the 5/6 field period. The heads Ha and Hb shown in FIGS. 8(A) and 8(B) are 5/
Since one track can be formed within a six-field period, one field of video signal can be recorded on one track, similar to the VTR with the head arrangement shown in FIGS. 7(A) and 7(B). Video signals can be recorded in this format. That is, a VTR with a head arrangement as shown in FIG.
By recording the video signal as described above, the tram diameter can be reduced to 315 mm compared to the VTR with the head arrangement shown in FIG.

Furthermore, if the time axis of the reproduced video signal is expanded by 615 times per field, it is possible to perform the same reproduction with the VTR with the head arrangement shown in Fig. 8 as with the VTR with the head arrangement shown in Fig. 7. .

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

In addition, VT using a small tram as shown in Fig. 8 above is also available.
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.

SUMMARY OF THE INVENTION In view of the above-mentioned background, an object of the present invention is to enable high-speed dubbing while monitoring dubbing signals using a rotating head type device that is small and has a simple configuration.

[Means for Solving the Problems] With this object in mind, the present invention provides a tape-like recording system 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. A dubbing system for duplicating a medium, which uses N rotating heads (N is an integer of 2 or more) that have different azimuth angles between adjacent heads and that rotate closely to each other to copy a first tape-shaped A playback device that plays back video signals on N adjacent tracks on a recording medium as N-channel signals, and N rotary heads that rotate closely and have different azimuth angles between the adjacent heads. a recording device for recording the reproduced N-channel video signals on a second tape-shaped recording medium while forming N adjacent tracks; and a recording device for recording the reproduced N-channel video signals while forming N adjacent tracks; and monitor means for monitoring the input dubbing signal.

[Function] As mentioned above, by using N rotating heads that have different azimuth angles and rotate closely, the rotational speed of the rotating heads can be increased and the diameter of the tram on which the rotating heads are held can be increased. It is possible to perform dubbing on a tape-shaped recording medium in which a large number of tracks with different azimuth angles are formed between adjacent tracks without increasing the size, and to record and reproduce data using the N rotating heads. By monitoring using only one channel of the N-channel video signals, it has become possible to easily monitor during high-speed dubbing.

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

FIG. 1 is a diagram showing a schematic configuration of a dubbing system as an embodiment of the present invention, and FIGS. 2(A) and (B) are head configurations of a reproducing side VTR and a recording side VTR of the system shown in FIG. FIG.

The head configuration of the reproducing side and recording side VTR in the system of this embodiment is different from the head configuration shown in FIGS. 8(A) and 8(B), in which the heads Ha and Hb are one track pitch (ITP) in the direction of the rotation axis. The difference is that the heads Ha and Hb are shifted and placed on an electrostrictive element 61 as an actuator for displacing them in the direction of the rotation axis.

In Figure 1, P is the playback side VTR%R is the recording side VTR
In order to simplify the explanation, only the parts related to the playback and recording functions are disclosed, but any of the VTRs may also have a recording and playback function.

40 and 41 are magnetic tapes, and their recording format is the same as that of the VTR having the head configuration shown in FIG. 7 described above.

First, the normal playback operation of the playback VTR shown in FIG. 1 will be explained. When a normal playback command is issued from the operation unit 34, the system controller 35 controls the servo circuit 17 to control the capstan motor 42, and the capstan C transports the tape 1 by one track per one field period. .

On the other hand, the system controller 35 uses the servo circuit 17 to control the drum motor 43 so that the drum D rotates once per field period. At this time, the heads Ha and Hb each trace each track one track at a time, or during one field period in which the head Ha traces the track Ta having the azimuth angle corresponding to the head Ha, the head Hb Track T with azimuth angle corresponding to
This means that head Hb is tracing b, and heads Ha and Hb can take out reproduced signals during this period. On the other hand, in the next one field period following this one field period, the head Ha traces the track Tb, and the head Hb traces the track Ta, making it impossible to extract the reproduced signal.

FIG. 3 is a timing chart for explaining the operation of each part of the dubbing system of this embodiment. In the figure, AI,
B1. A2 . . . indicates a video signal for one field. In the VTR in the dubbing system of this embodiment, the video signal as shown in FIG. 3(a) is originally as shown in FIG.
It is reproduced as shown in c) and (cl). In addition, in the case of a VTR with the head arrangement shown in FIG. 7 mentioned above, the head arrangement shown in FIG.
A reproduced signal as shown in is obtained.

The reproduced signal from the head Hb is delayed by one field period in the l-field delay circuit 18, and is input to the switch 11 together with the reproduced signal from the head Ha. The switch 11 is connected to the head Ha side (side A in the figure) during one field period in which the heads Ha and Hb can reproduce signals, and is connected to the delay circuit IB side (side A in the figure) during one field period adjacent to this.
The system controller 35 is connected to the B side in the figure).
controlled by As a result, the output No. 8 of the switch 11 becomes a signal of each field or a signal whose time axis is simply compressed to 5/6, as shown in FIG. 3(b).

Figure 4 shows the 4 images played on the VTR of the system of this embodiment.
It is a figure for explaining No. 3. FIG. 4(a) shows the spectrum arrangement of the signal recorded and reproduced by the VTR with the head arrangement shown in FIG. 7, and FIG. 4(b) shows the spectrum of the signal recorded and reproduced by the VTR in the system of this embodiment. Show placement. In the figure, Y is an FM modulated luminance signal, and A
As is clear from FIG. 4, where C is an FM modulated audio signal and C is a low frequency converted chroma signal, the frequency of the signal output from the switch 11 in this embodiment is the same as that of the VTR with the head arrangement shown in FIG. This is 1.2 times that of the reproduced signal, and the operating frequency of the reproduced video signal processing circuit 12 is 12 times that of the VTR with the head arrangement shown in FIG.

The reproduced video signal processing circuit 12 obtains a reproduced luminance signal obtained by FM demodulating the FM modulated luminance signal in the signal output from the switch 11 and frequency-converts the chroma signal converted to the low frequency band to the original band. A reproduced video signal obtained by mixing the reproduced chroma signal is output. The synchronization separation circuit 16 separates the synchronization signal from the reproduced video signal and supplies it to the servo circuit 17, which is used as a reference signal for controlling the tram motor 43 and capstan motor 42 as described above.

Incidentally, the servo circuit 7 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.

This reproduced video signal can also be output from terminal 15c. However, since this reproduced video signal is a signal whose time axis has been compressed to 5/6 of the signal of each field, when monitoring the reproduction on an external monitor etc., the signal of each field is compressed by the time axis expansion circuit 13. The time axis is extended to 615 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.

Next, the normal recording operation of the recording side VTR in FIG. 1 will be explained. Recording side VT in the system of this embodiment
R is assumed to be a camera-integrated VTR, and has the above-mentioned dedicated video camera (overscan camera) 31. The head configuration is the same as that of the reproducing VTR, but a ``''' is added for distinction. As described above, the camera 31 outputs a video signal as shown in FIG. 3(b), and inputs it to the B terminal of the switch 22, while 32 is an external input terminal, and a continuous video signal as shown in FIG. 3(a) is inputted to the B terminal of the switch 22. video signal is input. The time axis compression circuit 33 compresses the time axis of this video signal to 5/6 for each field to produce a signal as shown in FIG.

Furthermore, the terminal 21c is a terminal for inputting a video signal as shown in FIG. 3(b), and the video signal inputted to the terminal 21c is supplied as is to the A terminal of the switch 22.

When the normal recording mode is selected by the operation unit 36 and the switch 22 is instructed as to which input signal to record, the switch 22 records the selected signal in the video signal processing circuit 2.
3 and the synchronous separation circuit 24.

The servo circuit 26 receives information supplied from the system controller 37 according to the operation of the operation unit 36, and the synchronization separation circuit 2.
Using the synchronization signal separated at 4, the capstan motor 4
4, the capstan C° transports the tape 41 one track per field period, and the tram motor 45 transports the drum D' or one track per field period.
Control the rotation.

The recording video signal processing circuit 23 performs FM modulation on the luminance signal and converts the subcarrier frequency of the chroma signal to a low frequency, as shown in FIG.
A signal as shown in b) is provided to the switch 25. The switch 25 alternately switches to the delay circuit 19 side for each field.
Connected to the head Hb' side. As a result, the head H
The signals supplied to a', Hb" are shown in FIG.
). The heads Ha and Hb' are shifted from each other by one track pitch in the rotation axis direction, and the head H
Tape 4 is slightly ahead of head Hb'.
Trace 1. As a result, two tracks are simultaneously formed by heads Ha' and Hb' once every two fields, and as a result, as shown in FIGS. It becomes possible.

The signal output from the switch 22 has a period of one field period, and 5. '66 Dedicated monitor (overscan monitor) that scans from the top to the bottom of the monitor screen within one field, and has a horizontal scanning frequency of 5/6 of the normal one (overscan monitor) 4
9, and the recording state is monitored. This monitor 4
Reference numeral 9 is used as a so-called electronic viewfinder in a camera type VTR. In addition, a time axis expansion circuit 16 is provided to expand the time axis of each field signal to 615 so that it can be monitored on an external monitor.The output of this time axis expansion circuit 16 is shown in FIG. 3(a). The signal is outputted from the terminal 17 as a normal video signal.

Next, the operation during dubbing using the above-mentioned reproduction side and recording side VTR will be explained.

Output terminals 15a and 15b of the reproduction side VTR and the recording side VTR
When the input terminals 21a and 21b of the VTR are connected and the dubbing mode is specified using the operation section 34 of the playback VTR and the operation section 36 of the recording VTR, the servo circuits 17.26 control the capstan motors 42.44, Stan c, c
' The tape 40.41 is transported by two tracks per field period, and the drum motor 44°45
is controlled such that drums D and D' rotate once per field period.

As a result, the reproducing heads Ha and Hb each trace the tape 40 every two tracks. As mentioned above, the servo circuit 17 performs tracking control so that the output of the switch 11 is maximized, so that the playback heads Ha, H
b traces only tracks Ta and Tb, respectively.

However, since the transport speed of the tape 40 is different from that during normal playback described above, the heads Ha and Hb cannot trace parallel to the tracks. This will be explained using FIG. 5. In FIG. 5, ν1 is a vector corresponding to the running of the tape 40 during normal reproduction, and τ0 is a vector corresponding to the rotation of the reproduction heads Ha and Hb. is their composite vector. During dubbing, the vector corresponding to the running of the tape 40 becomes 2τa, and the composite vector becomes moss. Ma this vector hundred. In order to match the vector νC, in this embodiment, the electrostrictive element 61 made of a bimorph plate provides a motion corresponding to the vector νC.

That is, during the 5/6 field period in which the heads Ha and Hb are tracing on the tape 40, the electrostrictive element 61 continuously shifts the heads Ha and Hb by one track in the direction of the rotation axis, and the remaining 1/6 field is The resetting operation is repeated for each field during the field period. This operation is performed by servo circuit 1
given by 7. As a result, the heads Ha, Hb
traces in a direction parallel to the track, and the tracks Ta and Tb are accurately traced by the above-mentioned tracking control.

In Fig. 2(B), 61 is a bimorph plate, and 62 is a bimorph plate.
is a terminal to which a control signal from the servo circuit 17 is applied;
63 is a sensor such as a strain cage. This sensor 6
Reference numeral 3 is a device capable of detecting the absolute position of the heads Ha and Hb in the rotation axis direction, and is provided to accurately determine the positions of the heads Ha and Hb during normal recording and reproduction. The output of the sensor 63 is fed back to the servo circuit 7.

The reproduction signals of the heads Ha and Hb during this dubbing are shown in FIGS. 3(e) and 3(f). This signal is the reproduction amplifier 4
It is supplied to output terminals 15a, 15b via 6a, 46b.

On the other hand, the switch 11 is always connected to the A side, and the switch 11 is always connected to the A side.
) is supplied to the reproduced video signal processing circuit 12, and is outputted by the time axis expansion circuit 13 in a signal form that allows reproduction to be monitored on an external monitor or the like. As a result, a video signal reproduced at double speed, that is, a video signal for every other field is output from the terminal 14, and monitoring during dubbing can be realized by supplying this video signal to an external monitor device. However, in the case of an interlaced video signal, only odd fields are repeatedly output, so it is necessary to delay every other field by % horizontal scanning period to prevent skew from occurring.

The recording side VTR receives the information from the reproduction side VTR as shown in Fig. 3(e), (
A signal as shown in f) is sent to the terminal 21a.

21b, and is supplied to the heads Ha' and Hb' via recording amplifiers 47a and 47b. Head Ha',
Hb' is adjusted by the electrostrictive element 61° to the reproduction side head Ha, H
A displacement similar to 1b is applied, which is controlled by a servo circuit 26.

As a result, the heads Ha' and Hb' trace on the tape 41 in the same direction as during normal recording.
Video signals for two fields are simultaneously recorded on adjacent tracks with different azimuth angles. This operation is performed every one field period.

This realizes dubbing at twice the speed of normal recording and reproducing operations.

Further, the video signal reproduced at double speed from the reproduced signal processing circuit 12 is sent to the switch 22 via terminals 15c and 21c.
Supplied to the terminal. During dubbing, the system controller 37 connects the switch 22 to A@, and connects the recording video signal processing circuit 23 and the heaters FHa', H
Therefore, the video signal supplied to the A terminal of the switch 22 is supplied to the overscan dedicated monitor 49 and the time axis expansion circuit 16, and the dubbing state is monitored on the monitor 49, and the video signal supplied to the A terminal of the switch 22 is It is output from terminal 17 as a signal.

According to the dubbing system of the embodiment described above, by using a VTR with a small drum diameter, without increasing the number of heads, and by simply adding simple circuits such as a dubbing terminal and an amplifier, it is possible to use a VTR that is twice as large as a normal one. High speed dubbing is possible.

Further, by providing a bimorph plate or the like, it can be used also as a VTR for normal recording and reproduction, and the system can be used efficiently.

Furthermore, since the configuration is such that monitoring is performed during dubbing using only the reproduced signal from the head Ha, it has become possible to easily perform monitoring during high-speed dubbing.

FIG. 6 is a diagram showing the configuration of a dubbing system as another embodiment of the present invention. Components similar to those in FIG.

In the system shown in FIG. 6, monitoring during dubbing is performed at the input terminal 21a of the recording device R.

This is performed on the recording apparatus side using only one of the two channels of dubbing signals input to 21b.

That is, the video signal in the RF signal state from the switch 21a is made into a signal state suitable for monitoring in the reproduced video signal processing circuit 71 similar to the circuit 12, and
The signal is supplied to the skew correction circuit 73 via the terminal B of the skew correction circuit 73 .

During dubbing, the skew correction circuit 73 performs processing to prevent the occurrence of skew by delaying every other field by % horizontal scanning period as described above in response to instructions from the system controller 37. The output signal of the skew correction circuit 73 is supplied to the overscan dedicated monitor 49 and the time axis expansion circuit 16, the dubbing state is monitored by the monitor 49, and outputted from the terminal 17 as a normal video signal.

Further, during normal recording, the switch 72 is connected to the A side by the system controller 37, and the skew correction circuit 73 is connected to the A side.
functions are entrained so that monitoring similar to the system of FIG. 1 is performed.

In the embodiment shown in FIG. 6 described above, since one of the two channels of dubbing signals is used for monitoring,
Similar to the system shown in Figure 1, monitoring during high-speed dubbing can be easily performed, and the dubbing status can be monitored on the recording device side without making any connections other than those required for dubbing. became.

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). Tatashi,
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 is constructed assuming a VTR using a small drum, or the present invention can be applied to any video signal recording/reproducing device of the rotating head type and the same effect can be obtained. However, the embodiments can be modified as appropriate within the scope of the claims.

[Effects of the Invention] As explained above, the dubbing system of the present invention realizes high-speed dubbing using a rotating head type device that is small and has a simple configuration, and can monitor rice and dubbing signals. A dubbing system that can be easily performed can be constructed.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a schematic configuration of a dubbing system as an embodiment of the present invention, and FIGS. Figure 3 is a timing chart showing the signal processing timing of each part in the system shown in Figure 1. Figure 4 is a diagram for explaining the video signals handled by the system shown in Figure 1. FIG. 5 is a diagram for explaining head trace trajectories during normal recording and playback and dubbing in the VTR of the system shown in FIG. 1, and FIG. 6 is a schematic diagram of a dubbing system as another embodiment of the present invention. Figure 7 (A) and (B) are diagrams showing the head arrangement of a conventional general VTR. Figures 8 (A) and (B) are diagrams showing the configuration of a conventional VT using a small drum.
FIG. 9 is a diagram for explaining a video camera used exclusively in a VTR whose head arrangement is shown in FIG. 8. In the figure, Ha, Hb, Ha', Hb' are rotating heads, c, c' are capstans, D, D' are drums, 11 is a switch, 12 is a reproduction video signal processing circuit,
17.26 are surf circuits, 18.19 are 1-field delay circuits, 42.44 are capstan motors, 40.41 are magnetic tapes, 43.45 are tram motors, 46a and 46b are playback Amplifier, 47a
. 47b is a recording amplifier, 61 and 61° are electrostrictive elements as actuators, 71 is a reproduction video signal processing circuit,
72 is a switch, and 73 is a skew correction circuit. Flood 5 Kasumi 1 AP5 and Ucho Nagisa Warari (B) /! ? o' 8th haze rA) Figure q

Claims (4)

[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,
Further, video signals on N adjacent tracks on the first tape-shaped recording medium are reproduced as N-channel signals using N rotating heads (N is an integer of 2 or more) that rotate closely. a reproducing device that reproduces the reproduced N-channel video signals onto a second tape-shaped recording medium using N rotary heads that rotate closely and have different azimuth angles between adjacent heads; 1. A dubbing system comprising: a recording device that records while forming N tracks; and a monitor unit that receives only one channel of the N-channel video signals and monitors a dubbing signal. (2) In the reproducing device, the N rotary heads reproduce the information signals on the N tracks in a period shorter than the predetermined period, and in the recording device, the N rotary heads 2. The dubbing system according to claim 1, wherein the N tracks are formed in a period shorter than a period of time. (3) The playback device includes a playback signal processing circuit that converts the playback video signal into a signal format that can be monitored, and each of the N rotary heads plays back one track of the video signal for each predetermined period. a dubbing mode in which the output of a predetermined one of the N rotary heads is always input to the reproduced signal processing circuit; Claim (1) characterized in that the apparatus has a normal reproduction mode in which information signals for one track are reproduced and outputs of the N rotary heads are sequentially supplied to the reproduced signal processing circuit. Dubbing system described in section. (4) The recording device includes a signal processing circuit that converts one channel of the N-channel video signals into a monitorable signal format, and an input terminal that can input video signals other than the N-channel video signals. and a recording signal processing circuit for converting the video signal from the input terminal into a signal format suitable for recording, and each of the N rotary heads records one track worth of video signal for each of the predetermined periods. , a dubbing mode in which the output of the signal processing circuit is supplied to the monitor means, and each of the N rotary heads records one track of the video signal from the recording signal processing circuit every N times the predetermined period. The dubbing system according to claim 1, further comprising a normal recording mode in which the video signal input to the input terminal is supplied to the monitor means.