JPH02203450A - Recording/reproducing device - Google Patents

Abstract

PURPOSE:To easily secure the synchronization between a video tape recorder VTR and a digital audio tape recorder DAT by controlling the driving speed of a 2nd magnetic tape of the DAT based on the output of a time code comparator so as to secure the zero difference. CONSTITUTION:The same time codes are written into the linear tracks of a VTR 1 and a DAT 2 respectively. Thus it is possible to decide the synchronizing state between the VTR 1 and the DAT 2 with comparison of time codes carried out regardless of the difference between frame cycles of the oblique scan tracks. Then a magnetic tape 8 of the VTR 1 is driven at a constant speed, and the drive of a magnetic tape 26 of the DAT 2 is controlled based on the output of a time code comparator 3. Thus the coincidence is secured between both time codes of the VTR 1 and the DAT 2. As a result, the VTR 1 and the DAT 2 are substantially synchronous with each other as long as the coincidence is secured between both time codes. In such a way, the synchronization is easily obtained between the VTR 1 and the DAT 2.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a recording and playback system that can reproduce signals by driving a video tape recorder (VTR) and a digital audio tape recorder (DAT) synchronously. Regarding equipment.

[Prior Art] It has already been proposed to write a time code (SMPTE time code) on a linear track in a diagonal scanning rotary head type VTR.

[The problem that the invention tries to solve! ! ! By the way, if a VTR and a DAT can be driven synchronously, it becomes possible to record and reproduce both video signals and audio signals with high fidelity.

However, the 7-frame period of a VTR is 33.3n+s, and the frame period of a rotating head type DAT is 301s, so it is not possible to take a frame period.

Furthermore, in DAT, since digital signals are recorded on helical tracks, audio output cannot be obtained continuously during high-speed searches, and manual cueing cannot be easily achieved.

Therefore, an object of the present invention is to provide VTRs with different frame periods.
An object of the present invention is to provide a recording and reproducing apparatus capable of synchronously reproducing first and second information signals by substantially synchronously driving DAT and DAT.

Another object of the present invention is to provide a recording/reproducing device that can easily perform manual searches.

[Means for Solving the Problems] To achieve the above object, the present invention provides a first magnetic tape in which a first information signal is recorded on a diagonal track and a first time code is recorded on a linear track. a video tape recorder that reproduces and outputs the first information signal from the video tape recorder, and also reproduces and outputs the first time code;
reproducing the second information signal from a second magnetic tape on which a second information signal is recorded on a diagonal track and a second time code that is the same as the first time code on a linear track; a digital audio cheese recorder that outputs and reproduces and outputs the second time code; and a digital audio cheese recorder that reproduces and outputs the second time code; a time code comparison circuit that compares the time code and forms a signal corresponding to the difference between the two; and a second time code comparison circuit of the digital audio tape recorder that adjusts the difference to zero based on the output of the time code comparison circuit. The present invention relates to a recording/reproducing apparatus including a control circuit for controlling the running speed of a magnetic tape.

[Function] In the present invention, the same time code is written in the linear tracks of both the VTR and the DAT. Therefore, the state of synchronization between the two can be determined by comparing the time codes, regardless of the difference in the frame period of the diagonal scanning tracks. The magnetic tape of a VTR is run at a constant speed,
If the running of the DAT's magnetic tape is controlled based on the time code comparison output, both time codes can be made to match.0 If both time codes match, the VTR and DAT are essentially in sync. It turns out.

In claim 2, even when the magnetic tape is run at a speed higher than the normal speed for searching, the reproduced sound can be continuously obtained based on the fixed magnetic head, thereby knowing the desired reproduction location. becomes possible.

[Example] Referring to FIGS. 1 to 4, VT according to an example of the present invention
The R-DAT synchronous operation system will be explained.

This system consists of VTRI and DAT2 as shown in Figure 1.
, a time code comparison circuit 3 and a time code generation circuit 4.

VTRI is a general-purpose VHS or beta type small VT.
Similarly to R, a pair of video heads 6 that rotate together with the drum 5, a motor 7 for rotating the drum 5, a capstan 9 for running the first magnetic tape 8 at a constant speed, and a pinch roller 10 are provided. , a capstan motor 11, a reel motor 15.16 for driving a pair of reels 13.14 of a tape cassette 12, and a recording/reproducing circuit 18 connected to a pair of video heads 6 via a rotary transformer 17. In addition to this, it is also equipped with a fixed magnetic head 19 for recording and reproducing time codes. The fixed magnetic head 19 uses a time code recording/reproducing circuit 19 during recording.
It is connected to the time code generating circuit 4 through the contact point R of the changeover switch 20 and the time code recording/reproducing circuit 19a during synchronous playback, and to the time code comparison circuit 3 through the time code recording/reproducing circuit 19a and the contact point P of the changeover switch 20. Although the VTRI further includes various circuits, these are omitted.

As shown in FIG. 2, the first magnetic chip 8 has three linear tracks 8b and 8C18d in addition to a diagonal track 8a for recording and reproducing video signals. Diagonal track 8a
is scanned by the video head 6 and the first linear track 8
b is scanned by the time code recording/reproducing magnetic head 19,
The second linear track 8C is scanned by an audio head (not shown), and the third linear track 8d is scanned by a control head (not shown).

Like a general DAT, the DAT 2 includes a pair of magnetic heads 22 that rotate together with a drum 21, a recording/reproducing circuit 24 connected to this pair of magnetic heads 22 via a rotary transformer 23, and a motor that rotates the drum 21. 25, a capstan 27 for driving the second magnetic tube 26 at a constant speed, a pinch roller 28, and a capstan motor 2.
9, a reel motor 33, 34 for rotating the pair of reels 31, 32 of the tape cassette 30, and a capstan servo circuit 35, as well as a magnetic head 36 for time code recording and reproduction, and a time code recording/reproducing magnetic head 36. Regeneration circuit 3
6a, an audio signal recording/reproducing magnetic head 37, an audio signal recording/reproducing circuit 38, and a time code recording/reproducing changeover switch 39. The time code recording/reproducing magnetic head 36 is connected to the time code recording/reproducing circuit 36 during recording.
It is connected to the time code generating circuit 4 through the contact point R of the changeover switch 39 and the time code recording/reproducing circuit 36a and the time code comparison circuit 3 during reproduction.

As shown in FIG. 3, the second magnetic tape 26 has a diagonal track 26a for recording and reproducing PCM signals, and linear tracks 26b and 26c.The diagonal track 26a is scanned by the rotating magnetic head 22, and the linear track 26b is scanned by a magnetic head 36 for recording and reproducing time codes, and the linear track 26c is scanned by a magnetic head 37 for recording and reproducing audio signals. The heads 36, 37 are constructed as composite heads (multi-track heads). In addition, the diagonal track 26
A is provided with a PCM area A, a subcode area B, and an ATF area C according to the DAT track format, and the absolute time is written in the subcode area B. This absolute time can be read by both normal scanning and fast forwarding.

As shown in FIG. 4, the capstan servo circuit 35 is connected to a frequency signal generator (FG) 41 that generates a frequency signal corresponding to the rotation of the capstan 27, a reference frequency signal generator 42, and the like. Consisting of a phase comparison circuit 43 and a speed servo circuit 44, the output of the phase comparison circuit 43 is selectively input to the speed servo circuit 44 via a switch 45a, and the output of the switch SW shown in FIG. 45b.

The time code conversion circuit 46 shown in FIG. 1 converts the absolute time read from the subcode area B of the diagonal track 26a of the magnetic tape 26 into a time code (SMPTE code). The control circuit 47 determines whether the difference between the time code obtained from the time code recording/reproducing circuit 19a of the VTRI and the time code obtained from the time code conversion circuit 46 is within a predetermined time (for example, 3 seconds), and If the difference is greater than seconds, DAT2 is set to fast forward mode to make the difference within 3 seconds, and when the difference is within 3 seconds, the fast forward mode is canceled and the capstan servo state is established. Therefore, the control circuit 47 connects the capstan servo circuit 35 to the capstan servo circuit 35 via the contact a of the switch SW.
It also sends DAT control commands such as fast forward, rewind, and stop from line 49. A system control circuit 48 is provided to achieve synchronization based on the output of the time code comparison circuit 3, and this output is connected to the capstan servo circuit 35 via the contact of the switch SW.

Note that in order to match both time codes, it is necessary to control the tape running device and the signal processing circuit other than the capstan motor 29, but these are omitted from illustration.

[Operation] During recording, a video signal is supplied to a pair of video heads 6 in the VTRI and recorded on the diagonal track 8a, and a digital signal (PCM signal) corresponding to an audio signal related to the video signal is diagonally recorded in the DAT 2. It is recorded on track 26a. At the same time, an audio signal or a corresponding analog audio signal is transmitted to the DAT2.
is supplied to the magnetic head 37, and analog recording of music and the like is performed on the linear track 26c. Further, an SMPTB time code is generated from the time code generation circuit 4, and recorded on the linear track 8b by the magnetic head 19 in the VTRI, and recorded on the linear track 26b by the magnetic head 36 in the DAT2.

Note that the SMPTE time code consists of frames, seconds, minutes,
It is a standard that expresses time information in 80 bits, and is film-based.

During playback, the diagonal track 8 of the magnetic tape 8 of the VTRI is
The video head 6 reproduces and outputs the video signal from a, and also plays the diagonal track 26 of the magnetic tape 26 of the DAT 2.
The rotary head 22 reproduces the PCM signal, and the recording/reproducing circuit 24 converts it back into an analog signal and outputs it.

When synchronizing the playback output (video signal) of the VTRI and the playback output (audio signal) of the DAT2, first
Along with reading TRI's SMPTE time code, D
Diagonal track 2 with AT2 in normal playback or pause state
The absolute time is read from the subcode area B of 6a and converted into a timecode (SMPT) by the timecode conversion circuit 46.
E), and the control circuit 47 determines whether the time difference between the two time codes is within 3 seconds. If the 0 time difference is greater than 3 seconds, the second magnetic tape 26 is fast-forwarded or rewinded to reduce the time difference. Do it within 3 seconds. This control is performed at a variable speed IINM+, that is, when the time difference is large, the tape is run at high speed, and as the time difference becomes smaller, the tape running speed is lowered.

To carry out this control, control circuit 47 connects line 49
In addition, instead of issuing commands such as fast forward, rewind, and stop within 3 seconds by automatic control, an audio signal is detected from the linear track 26C of the second magnetic tape 26,
Based on this, you can know the synchronization status between VTR1 and DAT2, and manually operate DAT2 to fast forward or rewind mode so that they are synchronized.When the 0 time difference is within 3 seconds, switch DAT2 to normal playback mode. Return, linear track 2
The time code is read from 6b and inputted to the time code comparison circuit 3, and the phase difference between both time codes is determined and sent to the system control circuit 48. The system control circuit 48 controls the operating speed of the entire system by varying the master clock of the digital system, and applies a control signal (phase correction signal) corresponding to the phase difference to the capstan servo circuit 35 to control the cabstan 27. The line 50 controls the positional relationship between the magnetic tape 26 and the time code recording/reproducing magnetic head 36, and the line 50 controls the entire system to match the time codes of the VTRI and DAT2. Furthermore, because of the time required for absolute time signal processing, DAT
An error of within 17 frames (30 r#s) occurs, but this is considered as an allowable error. However, in consideration of the PCM signal processing time in DAT2 (<30 m5), the reproduction in DAT2 may be configured to precede the reproduction in VTRI by 301S.

When using VTRI alone or DAT2 alone, the synchronization circuit using time code is disconnected.

When using the DAT2 alone, when performing a reproduction search at a variable speed or a speed different from the normal speed, the audio signal of the linear track 26c is reproduced, and the PCM signal of the diagonal track 26a is reproduced based on this reproduced sound. Judging the content. When the magnetic tape 26 is running at variable speed, the PC
Although it is not possible to continuously obtain audio information based on the M signal, it is possible to continuously obtain the reproduction sound of the audio information on the linear track 26c, and it is possible to cue the desired reproduction location.

[Modifications] The present invention is not limited to the above-described embodiments, and, for example, the following modifications are possible.

(1) The circuit portion for synchronization may be formed independently as a synchronizer, or may be included in the VTRI or DAT2.

(2) The capstan servo circuit 35 is not limited to the one shown in FIG. 4, but can be modified in various ways.

For example, a circuit that corrects out-of-sync of one frame or more,
The circuit may be configured separately from a circuit that performs phase control over a range smaller than one frame.

[Effects of the Invention] As described above, according to the present invention, it becomes possible to easily synchronize a VTR and a DAT.

Moreover, according to claim 2, the search can be easily accomplished.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a composite system of a VTR and DAT according to an embodiment of the present invention, FIG. 2 is a plan view showing a magnetic tape of a VTR, and FIG. 3 is a plan view showing a magnetic tape of a DAT. FIG. 4 is a block diagram showing the capstan servo circuit. Engineering... VTR, 2... DAT, 6... Video head, 8... First magnetic tape, 19... Magnetic head for time code recording and reproduction, 22... Magnetic head, 26
...Second magnetic tape, 27...Capstan, 3
5... Capstan servo circuit, 36... Magnetic head for recording and reproducing time code, 37... Magnetic head for recording and reproducing audio signal.

Claims (1)

[Claims] [1] The first information signal is recorded on the diagonal track and the first time code is recorded on the linear track.
a video tape recorder that reproduces and outputs the first information signal from a magnetic tape and also reproduces and outputs the first time code; a second information signal is recorded on a diagonal track, and a second information signal is recorded on a linear track; A digital device that reproduces and outputs the second information signal from a second magnetic tape on which a second time code that is the same as the first time code is recorded, and also reproduces and outputs the second time code. an audio tape recorder, and a time for comparing the first time code obtained from the video tape recorder and the second time code obtained from the digital audio tape recorder to form a signal corresponding to the difference between the two; A recording and reproducing device comprising: a code comparison circuit; and a control circuit that controls the running speed of the second magnetic tape of the digital audio tape recorder so that the difference becomes zero based on the output of the time code comparison circuit. . [2] Information signals are digitally recorded on diagonal tracks,
a magnetic tape on which analog audio signals are recorded on linear tracks; a rotating magnetic head for reproducing information signals from the diagonal tracks; and a rotating magnetic head that runs the magnetic tape so as to scan the diagonal tracks. A recording and reproducing apparatus comprising: a tape running device; and a fixed magnetic head for reproducing the audio signal from the linear track, and configured to reproduce the audio signal using the fixed magnetic head during a search.