JPH0430304A - Dubbing system - Google Patents

Abstract

PURPOSE:To attain dubbing of a recording tape medium with lots of tracks formed thereon at a speed of a multiple of N by employing N-sets of rotary heads having different azimuth angles and driven closely to each other. CONSTITUTION:Servo circuits 17, 26 control capstan motors 42, 44, capstans C, C' carry tapes 40, 41 by two tracks each for one field period and drums D, D' are driven once for the one field period. An electrostriction element 61 repeats the operation that the element shifts continuously heads Ha, Hb by one track in the direction of the rotary axis for a 5/6 field when the heads Ha, Hb trace on a tape 40 and resets the heads Ha, Hb for remaining 1/6 field. A recorder side VTR receives a signal from a reproducer side VTR and gives the signal to the heads Ha', Hb'. The heads Ha', Hb' trace a tape 41 and record a video signal by two fields simultaneously onto adjacent tracks with different azimuth angles. Thus, the dubbing is attained at a double speed in comparison with the speed of the usual recording and reproduction.

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 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 denote tape guides for winding the tape 1 around the outer periphery of the rotating drum 3 over an angular range of 180 degrees or more.

These rotating heads are attached to the rotating tram 3 with a phase difference of 180 degrees from each other, and as shown, they are attached at the same height in the direction of the rotation axis and have different azimuth angles. As is well known, the head HAHB records and reproduces one field's worth of video signals while rotating 180 degrees.

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 in the past as VTRs that can reduce the diameter of the drum.
FIG. In the mouth, Ha and Hb are rotating 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.

F(b records one field's worth of video signals during each 300° rotation. In other words, one field's worth of video signals is recorded in a period shorter than the original one field period of the video signal. It turns out.

Therefore, the video signal recorded by this type of VTR is N.
When assuming a TSC signal, instead of a normal NTSC signal, i.e. a signal with a vertical scanning frequency (fv) of 60 Hz and a horizontal scanning frequency (fh) of 15.75 kHz,
60H2, fh is 18.9 (15,75x 615)
Must be of kHz.

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

The dedicated video camera above has a screen with an aspect ratio of 9.1 (
(indicated by point j + IY in Fig. 8), and output the aspect box 3:4 screen shown by point #IX in Fig. 8 as the effective screen within the 5/6 filtration period. There is. 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 on one track.
It is possible to record video signals in a format similar to that of a VTR with the head arrangement shown in Figures (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 time axis of the reproduced video signal is 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.

[Problem to be Solved by the Invention] Generally speaking, when dubbing a tape using two VTRs, for example, when dubbing two hours worth of video information, it takes two hours to convert the standard television signal. Real I3 that transfers! Inter-dahing 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', the time axis is compressed to 5/6 at the one-field position, the time axis is first expanded, the format is converted to a standard television signal, and then the video signal is time-axis compressed to 5/6 at the one-field position. It was extremely difficult to achieve high-speed dubbing, as various processes were required, such as compressing the time axis in units of one word.

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 system is provided in which a number of tracks are formed, each of which records information signals for a predetermined period, and adjacent tracks have different azimuth angles. The medium dubbing system is configured to cause the first tape-shaped recording medium to travel N (N is an integer of 2 or more) tracks at a time during the predetermined period of time, and to record N pieces of tape having different azimuth angles and rotating close to each other. a reproducing device that reproduces information signals on N adjacent tracks on the first tape-shaped recording medium as N-channel signals using a rotating head; The reproduced N channel signals are transferred to the second tape-shaped recording medium by using N rotary heads that rotate N tracks at a time and have different azimuth angles and rotate close to each other. The present invention is comprised of a recording device that records while forming N tracks.

[Operation] As mentioned above, by using N rotating heads that have different azimuth angles and rotate closely, it is possible to increase the rotational speed of the rotating heads and to reduce the diameter of the drum on which the rotating heads are held. It has become possible to perform dubbing on a tape-shaped recording medium in which a large number of tracks with different azimuth angles between adjacent tracks are formed at N times the speed without increasing the size.

[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 2(B) show heads of a reproducing side VTR and a recording side VTR of the system of FIG. FIG. 3 is a diagram showing the configuration.

In the system of this embodiment, the head configurations of the reproducing side and recording side VTRs are different from the head configurations shown in FIGS. 7(A) and 7(B) in that the heads Ha and Hb are one track pitch (ITP) in the direction of the rotation axis. The difference is that these 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, and 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 the recording format of these tapes is the same as that of the VTR having the head configuration shown in FIG. 6 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 tram motor 43 so that the drum D rotates once per field period. At this time, each of the heads Ha and Hb sequentially traces each track one track at a time, but during one field period in which the head Ha traces a track Ta having an 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 during this period heads Ha and Hb can be checked by taking out reproduced signals. 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, A...
B, , A2, . . . indicate video signals for one field. In the VTR in the dubbing system of this embodiment, the video signal as shown in FIG. 3(a) is as shown in FIG. 3(C).
, (d). Incidentally, in the VTR having the head arrangement shown in FIG. 7 described above, a reproduced signal as shown in FIG. 3(b) can be obtained.

The reproduced signal from the head FHb is delayed by one field period in the one-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 during one field period in which the heads Ha and Hb can reproduce signals, and is connected to the delay circuit 18 side during one field period adjacent thereto.

As a result, the output signal of the switch 11 becomes a signal obtained by simply compressing the time axis of each field signal to 5/6, as shown in FIG. 3(b).

FIG. 4 is a diagram for explaining signals reproduced by the VTR of the system of this embodiment. FIG. 4(a) shows the spectrum arrangement of the signal recorded and reproduced by the VTR with the head arrangement shown in FIG. 6, 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 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. 4, in this embodiment, the frequency of the signal output from the switch 11 is , is 1.2 times the reproduction signal of the VTR with the head arrangement shown in FIG. 6, and the operating frequency of the reproduction 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 divides the synchronization signal in the 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 capstan 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.

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 each field, when it is supplied to an external monitor etc., the time axis expansion circuit 13 converts the signal of each field into 615 times. It is expanded 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 8 terminals of the switch 22, while 32 is an external input terminal, as shown in FIG. 3(a). A continuous video signal is manually generated. 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 2C is a terminal for manually 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 human 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 moves the drum D' or one track per field period.
Control the rotating crosspiece.

The H self-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 to produce a signal as shown in FIG. 4(b), which is then supplied to the switch 25.

The switch 25 is alternately connected to the delay circuit 19 side and the head Hb' side for each field. As a result, the signal supplied to the head Ha' Hb is as shown in FIG. 3(c), (
d). Heads Ha and Hb' are 1
The head Ha traces the tape 41 slightly ahead of the head Hb' by being shifted in the direction of the track pitch rotation axis. As a result, two tracks are simultaneously formed by the heads Ha' and Hb' once every two fields, and as a result, recording similar to that of a VTR whose head arrangement is shown in FIGS. 6 and 7 becomes possible.

The signal output from the switch 22 scans the monitor screen from the top edge to the bottom edge in one field period and within 5/6 field periods, and changes the horizontal scanning frequency to the normal 5
/6 dedicated monitor (overscan monitor) 49
The recording status is monitored. This monitor 49
is used as a so-called τ-hue filter in a camera-integrated VTR. Also, 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 output from the terminal 17 as a normal video signal as shown.

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 treads 40, 41 are conveyed by two tracks every one field period, and the tram motors 44, 45 are controlled so that the drums D and D' rotate once per one 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, τ7 is a vector corresponding to the running of the tape 40 during normal reproduction, τ0 is a vector corresponding to the rotation of the reproducing heads Ha and Hb, and τ0 is a composite vector of these vectors. During dubbing, the vector corresponding to the running of the tape 40 becomes 2τ, and the resultant vector becomes 2τ. Ma this vector ma. In this embodiment, in order to match the vector τ. An electrostrictive element 61 made of a bimorph plate provides a motion corresponding to the above.

That is, during the 5/6 field period in which the heads Ha and Hb are tracing 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 During the field period, the reset operation is repeated for each field. 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 gauge. 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 will be fed back to the servo circuit 17.

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
6a and 46b to the output terminals 15a and 15b.

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 received from the terminal 21a21b and sent to the heads Ha' and Hb' via the recording amplifiers 47a and 47b.
supply to. Heads Ha' and Hb' are electrostrictive elements 6
1' gives the same displacement as the reproduction side heads Ha and Hb, and this is controlled by the 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.

According to the dubbing system of the above-described embodiment, a VTR with a small drum diameter is used, the number of heads is not increased, and simple circuits such as a dubbing terminal and an amplifier are added. High-speed dubbing is now 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.

In the above embodiment, the number of heads rotating close to each other is defined as two, but depending on the desired dubbing terminal, there are generally two heads rotating in close proximity.
(N is an integer of 2 or more). however,
If dubbing is performed using a format that performs azimuth recording and the head arrangement is as in the above embodiment, 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 tram, but the present invention can be applied to any rotary head type information recording/reproducing device such as a DAT (digital audio recorder). The embodiments can be modified as appropriate within the scope of the claims.

[Effects of the Invention] As described 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 the drawing]

FIG. 1 is a diagram showing a schematic configuration of a dubbing system as an embodiment of the present invention, FIGS. 2(A) and (B) are diagrams showing a head arrangement in a VTR of the system in FIG. 1, and FIG. Fig. 4 is a timing chart showing the signal processing timing of each part in the system shown in Fig. 1, Fig. 4 is a diagram for explaining video signals handled by the system shown in Fig. 1, and Fig. 5 is a typical diagram of the VTR in the system shown in Fig. Figures 6 (A) and (B) are diagrams showing the head arrangement of a conventional general VTR; Figures 7 (A) and (B) are diagrams for explaining head trace trajectories during recording and playback and dubbing; ) is a 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, 17.25 are servo circuits, 18.19 are 1
Field delay circuit, 4244 is a capstan motor, 40.41 is a magnetic tape, 43.45 is a drum motor, 46a, 46b is a playback amplifier, 47a
. 47b is a recording amplifier and an electrostrictive element as a 61.61° actuator, respectively.

Claims (1)

[Scope of Claims] (1) A dubbing system for duplicating a tape-shaped recording medium in which a number of tracks are formed, each recording an information signal for a predetermined period, and adjacent tracks have different azimuth angles, the dubbing system comprising: The first tape-shaped recording medium is made to travel by N tracks (N is an integer of 2 or more) in the predetermined period, and N rotary heads rotate closely and have different azimuth angles between adjacent heads. a reproduction device that reproduces information signals on N adjacent tracks on the first tape-shaped recording medium as N-channel signals; The reproduced N channel signals are transferred to the second tape-shaped recording medium by using N rotary heads that rotate in close proximity to each other and have different azimuth angles between adjacent heads. A dubbing system comprising: a recording device that records while forming N tracks; (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 Claim (1) characterized in that the N tracks are formed in a period shorter than the period of time.
Dubbing system described in section. (3) The playback device has a dubbing mode in which each of the N rotary heads plays back one track of information signals every predetermined period; and The dubbing system according to claim 1, further comprising a normal reproduction mode in which information signals for one track are reproduced every period. (4) The playback device includes an actuator that shifts the position of the N rotary heads in the rotation axis direction, and in the dubbing mode, the actuator shifts the position of the N rotary heads in the rotation axis direction at the predetermined period of time. The dubbing system according to claim 3, characterized in that the position of the dubbing system is changed. (5) The recording device has a dubbing mode in which each of the N rotary heads records information signals for one rack in each of the predetermined periods; The dubbing system according to claim 1, further comprising a normal recording mode in which information signals for one track are recorded for each period. (6) The recording device includes an actuator that shifts the position of the N rotary heads in the rotation axis direction, and the actuator shifts the position of the N rotary heads in the rotation axis direction at the predetermined period in the dubbing mode. The dubbing system according to claim 5, characterized in that the position of the dubbing system is changed.