JPS61150102A - Consecutive recording and editing circuit of video type - Google Patents

Abstract

PURPOSE:To attain excellent consecutive recording and editing without using a CTL (control) signal by constituting the circuit that a joint of a video tape is detected depending on the presence of a sound signal. CONSTITUTION:When a pause button is depressed while a helical scan type video tape recorder is in the recording mode by a switch 1, a switch 6 is turned off so as to record a video signal 500 and an ATF pilot signal 600 (f1-f4 on tape) only without a sound FM signal A on a video track of the tape. Then the tape running is stopped. When a pause button is depressed next, a head 2 detects an interblock of the signal A shown in B and new recording is started from the next interblock C. In this case, a system controller 4 activates the switch 1 as a composite reproduction mode P, a detection circuit 10 detects the presence of the signal A, an output signal of a D flip-flop 5 throws the switch 1 to the position of th recording mode R via an AND circuit 3. Thus, excellent consecutive recording and editing is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a splicing circuit for a video tape recorder (VTR) that performs iFM modulation on an audio signal and superimposes it on a video signal for recording.

[Technical background of the invention]

FIG. 4 is a tape operation diagram illustrating an example of a splicing method in this conventional VTR.

When the pause button is pressed in step 102 while the VTR is operating in step 101, step 10
At step 3, the VTR rewinds by 118 frames, and at step 104 it enters a standby state in pause mode.

Thereafter, when the pause is released in step 105, the tape is played back for 157 volts in step 106, and then, in step 107, the recording mode is entered and recording is started.

In addition, the 9th part indicated by P in the figure shows the overlapped part of 3 frames.

The fgs diagram shows an example of a tape pattern when 5t continuous shooting is performed using the above continuous shooting method.

After returning the tape (magnetic cable) to recording track A, when the pause is released, run tape 1 in playback mode until just before recording track C, and then lock the servo while playing the CTL signal at the CTL (control) track opening. After spending money, information is recorded by switching to the recording mode from the recording track and Kuha, but up to recording track 2 there are no overlaps.
Kiss me. Note that the arrow in the figure indicates the direction in which the tape travels.

FIG. 6 is a timing chart showing another example of the conventional continuous shooting method when transitioning from recording to pause mode. The figure shows the recording mode signal, the figure (6) shows the head switch, and the figure 0 shows the CTL signal.
It shows. When the ratio recording mode signal shown in the figure is at a high level and the VTR is in the recording mode, for example, if you press the Bose button / at time t to enter the pause mode, the duty of CTIJi, shown in the figure 0, changes. Sasera n
After recording on the tape, the recording mode signal (2) in the figure becomes low level, and the VTR enters the pause mode.

Figure 7 shows a timing chart for canceling the pause, playing continuous shots, and transitioning to the recording mode. In the same figure, 0 represents the capstan motor control signal, ■ also represents the playback mode signal, (F
5Fi, C switching pulse, Q is the regenerated CTL signal, and ■ is the C generated from the above regenerated CTL signal.
TL signal pulses are shown. When the pause release is activated at time t1, the capstan control signal shown in FIG. During this time, the same figure (to)
The reproduced CTLW pulse and the head switching pulse shown in [F] in the same figure are not synchronized until shown by , and then the servo is locked. After the servo lock is lost rLfc, the duty of the 7'hCTLIr pulse changes as shown by ■ in the figure at time 1. Then, at the same timing, the reproduction mode signal becomes low level and the %VTR shifts to the recording mode.

[Problems with background technology]

In the conventional splice shooting method as described above, the seam is detected by counting the CTL signal, or the duty of the CTL signal is changed and recorded, which is then used as the seam detection signal. However, the drawback was that it could not be used in a system without a CTL signal. In addition, even in systems using CTL signals, the CTL signal detection head may become clogged, making it difficult to expect good connection operation.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks, it is an object of the present invention to provide a video tape recorder using an audio FMI multiplex recording system that can perform excellent continuous shooting without using a CTL signal.

[Summary of the invention]

The invention achieves the above object by using a video tape recorder using an audio FM signal multiplex recording method (hereinafter referred to as the human FM method) with a configuration that detects joints based on the presence or absence of an audio FM signal. It is something.

[Embodiments of the invention]

Hereinafter, one embodiment of the invention will be described with reference to the drawings.

FIG. 1 is a comparative block diagram showing an embodiment of the recording and reproducing system of a video tape recorder' employing the inventive continuous shooting Vaa method. The switch 1 disconnects the path for supplying recording information from the recording system to the video head 2 and the signal path for inputting the playback signal from the video head 2 to the playback system.
The switching is performed by the system mode signal 1100 output from the AND circuit 3. AND circuit 3 has a system; 4 and the recording mode signal 100 from D flip-flop 5.

- the signal 200 is input, and these signals 100, 200
The logical OR is taken. An audio recording mode signal 300 is output from the system controller 4 to the switch, and by turning on and off the switch 6 using this mode signal 300, the audio signal 400 is supplied to the adder 7.
Shutdown is controlled. In the adder 7, the audio signal 4
0G and video signal and mu'l'li' (Automa
tie 'l'rach polloming) pyro and g signals 500 and 600 are added, resulting in a recording signal of 700
and is supplied to the 8 terminals of switch 1. Sui, chi1
The playback signal 8 of the video head 2 extracted from the P sperm of
00 is input to the filter 8, where only the reproduced audio FM signal is extracted. After this is input to the detection circuit 10 via the buffer 9t, the detection circuit 10 receives the audio FM signal.
Only the carrier signal of the signal is detected and its level is output to the comparator 11. The comparator 11 compares the input carrier signal level with a reference level, and when the input carrier signal level is lower than the reference level, it outputs an audio mute signal 900t-D flip-flop.

output to step 5. When the audio mute signal 900 is input to the D flip-flop P5, the mute signal 200 is output to the AND circuit 3 in synchronization with the switching valve 1000.
The output is T. Note that the reproduction signal 800 is input to a video reproduction system 20, a rear door reproduction system 30, a servo system 40, etc. (not shown).

Next, the operation on the unfavorable flow side will be explained according to the timing chart shown in FIG. VTR is in recording mode R17
) time is audio recording signal 300, recording mode Rin No. 10
0, audio mute signal 900% mute signal 20
0 and the system code signal 1100 are all at high level 29, the switch 1 is switched to the R terminal side, and the switch 6 is on, so the video head 2 receives the video signal 500 and the ATF pilot signal 600. and a recording signal 700 consisting of an audio signal 400 is supplied nl
This recording signal 700 is recorded on the video track of the tape. In a state of confusion, the Bose button was pressed at time t.
Immediately after that, at the falling edge of the switching pulse 1000, the system controller 4 sets the audio recording mode signal f signal 300i to low level and turns the switch 6f on. Therefore, from this moment on, the audio signal 400 is not supplied to the video head 2, and the video signal 500 from which the audio signal 400 is removed and the ATi' pilot signal 600 are
recorded on magnetic tape. Furthermore, this recording mode R
In this case, since no signal is input to the filter 8, the level of the audio FM carrier signal output from the detection circuit 10 is low level.

Therefore, the output 900 of the comparator 11 is at a high level, and therefore the D flip-flop 5 is set, and the mute signal 200, which is its cutting signal, is at a high level. Therefore, the AND circuit 3 is open, and the recording mode signal 100 outputted from the system controller 4 passes through the AND circuit 2 and becomes a high-level system mode signal 1100, so that n is supplied to the switch 1. I'm looking forward to it. Next, switching pulse 1000
When the falling edge becomes the next falling edge, the system controller 4 sets the recording mode signal 100 to a low level in synchronization with this falling edge. Therefore, the system mode signal 11
00 yet A-level, switch 1 is connected to terminal P
Switch to the side. Along with this, system controller 4
After rewinding the tape for a predetermined period of time in the VTRt-rewind mode RW, it enters a pause standby state PW. During this rewind mode RW, the playback signal 800 from the video head 2 enters the filter 8 unstablely, and the level of the audio FM carrier signal output from the detection circuit 9 also fluctuates unstablely. The audio mute signal 900 becomes low level or high level. For this reason, D Flip Flo.

The tap 5 is repeatedly set and reset, and the mute signal 200 also becomes unstable as indicated by the broken line in the figure. However, during this time, as mentioned above, because the recording mode signal 100 is at a low level, the system mode signal 11
00 remains at a low level, and switching of switch 1 does not occur. In the pause standby mode PW, the recording mode signal 100 continues to be at a low level, and since no signal enters the filter 8, the audio mute signal 90G becomes a high level again, and as a result, the mute signal 200 also goes to a high level. The state is as follows. In this state, time 1. When Bose is released, the system controller 4 sets the VTRt one-shot playback mode P to run the tape. With this method, the playback signal 8oo from the video head 2 is input to the filter 8 n1 playback audio F
The M signal is input to the detection circuit 1o. Therefore, the detection circuit 10 detects the carrier signal of the inputted n-sentence audio FM signal and outputs a high level signal to the comparator 11. For this reason, the comparator 11 sets the audio mute signal 900 to a low level and outputs a D-free signal since the input level signal is at a higher level than the reference No. 16.
Reset Pfrog 5. This method is determined by the output signal of the flop 5 in synchronization with the rising edge of the switching pulse 100 immediately after that.

-t signal 200 becomes low level, and AND circuit 3 is cut off. After that, the recording mode signal 1OOt-high level is sent to the system controller 4, but since the AND circuit 3 is cut off at that time, the system recording mode signal 1100 is still at a low level, and the video head 2
The reproduced signal 8oO is input to the filter 8 one after another.
Ru. When the video head 2 plays back the part of the tape in which only the audio signal 400 is not recorded in such a state,
The output of filter 8 is low level, and the detection circuit 1
The audio FM carrier signal level outputted by 0 becomes low level. From this &:, the comparator 11 detects that the input level signal has reached the standard Ecrow level, and
Set F, D7, Pflo, and P5 to set Audio Mito Z-M No. 900 to high level. Therefore, D
Nut signal 20 generated by the output signals of Furi, Pflo, and 15
0#2 becomes high level in synchronization with the rising edge of the switching pulse 1000 immediately after that. Therefore, the AND circuit 3 is opened, the recording mode signal 100 passes through this circuit 3, the system recording mode signal 110o is set to high level, and the switch 1 is switched to the R terminal side. At the same time, since the system controller number is set to VTR1--recording mode R, a recording signal 70G is supplied to the video and video recorder 2, and recording on the tape is started. At this time, since the recording mode signal 100 is at a high level in the continuous shooting playback mode P and the audio recording mode signal aooy is at a high level and the switch 6 is turned on, the recording signal 700 is a video signal. Contains all of the signals 500% ATF pilot inertia 600 and OI signal 400. In addition, in the continuous playback mode P in which the rewound portion of the tape is played back, the playback ATF pilot signal obtained during this period is made to match the reference ATF pilot inertia, and a tracking servo is applied. At this point, the system controller 4 outputs the recording mode signal 10.
0 and the audio recording mode signal 300 are set to high level at the same time.

FIG. 3 is a diagram showing an example of a tape pattern in the above operation. Symbols f1 to f4 in the figure are ATF pilot signals 6
00't-indicates, ■ indicates the Eirin signal 500t-, and human indicates the audio signal 400t-. Also, the symbol R indicates a portion where all the above signals are recorded, the symbol W indicates a 0 portion where only the audio signal person is excluded and recorded, and Q2 indicates a non-signal recorded portion. ing . Further, the symbol A indicates the track on which the video head 2 was recording at the time the pause button was pressed, and the symbol A indicates the track on which only the audio signal A was removed and recorded. When the pause is released, Ruru Tora detects the first non-recording of professional audio at the joint, and new recording starts from the next non-signal sickle section track. In addition, when a new recording is made to the no-signal recording area, the ATF pilot) ft f1
~f4 is recorded in order without disturbing the sequence because the servo is applied during the continuous shooting playback period P.

By configuring the main stream side to detect the joint based on the presence or absence of the audio signal 400 recorded on the audio track of the spliced tape,
It is possible to perform good continuous shooting without having a CTL signal.

〔Effect of the invention〕

As described above, the video tape recorder using the audio FM signal superimposition recording method of the present invention is configured to detect a seam based on the presence or absence of an audio signal that is multiplex recorded on an audio track of a tape. Good continuous shooting p'g without using a signal: There is an effect that can be achieved.

[Brief explanation of the drawing]

Figure 1 shows a friend audio F using nine continuous shooting circuits according to the present invention.
Figure 2 is a professional diagram showing an example of the recording and playback system of a video tape recorder using the Mffr superimposed recording method.
The operating waveform diagram of the video tape recorder shown in the figure during splicing, FIG. 3 shows an example of the tape pattern of splicing # by the device shown in FIG. 1, and FIG. 4 explains an example of the conventional splicing method. Figure 5 is an example of a tape pattern when fc is performed using the nine continuous shooting method shown in Fig. 4, and Figures 6 and 7 are operation diagrams showing other examples of the conventional continuous shooting method. Ruru waveform diagram. 1... Selector switch 2... To video, 3.
・・AND circuit 4・System controller 5・-D flip flow, 16・Switch 7・・・
Filter 9...Detection circuit IO-/Comparator agent Patent attorney Noriyuki Chika (and 1 other person) Figure 3 Figure 4

Claims (1)

[Claims] In a helical scan video tape recorder that superimposes an audio FM signal on a video signal and records it on a video track of a magnetic tape, when a recording pause button is pressed while operating in recording mode, the audio FM signal is superimposed on at least one video track. means for stopping the running of the magnetic tape after recording only the video signal except for the video signals; tape rewinding means for then rewinding the magnetic tape by a predetermined amount and then entering a standby state in a pause mode; The present invention is characterized by comprising a continuous shooting start control means for detecting the missing track of the audio FM signal as a continuous shooting playback mode when the state is released, and starting recording anew from the track next to this track. Video tape recorder splice circuit.