JPS60251546A - Magnetic recorder and reproducing device - Google Patents

Abstract

PURPOSE:To perform consecutive photographing with a less quantity of superposed recording, by starting the recording of a pulse train on a cue track after detecting the recorded final track when a magnetic tape is run in the reverse direction and, after the tape is run in the reverse direction for a prescribed quantity, running the tape in the forward direction. CONSTITUTION:When a temporary stop signal is inputted in a microcomputer 17 through an input terminal 27, a magnetic tape is run in the reverse direction and, at the same time, the reverse by running quantity is set in a timer memory 174 after the recording on the video track being recorded is completed. When a video head 21 is put on a video track while a timer 175 operates and the memory 174 makes the subtraction, a detect signal is inputted into the computer 17 through a detector circuit 200 and comparator 201. When the detect signal is inputted, the computer 17 judges that the final position of the video track has been detected and runs the magnetic tape in the forward direction after the tape is run in the reverse direction after the pulse train is recorded on the cue track. When the final track cannot be detected, video recording is started after the magnetic tape is run in the reverse direction for a prescribed quantity. Therefore, accurate consecutive photographing can be realized with a less quantity of superposed recording.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is a magnetic recording medium applied to a video tape recorder, etc., which employs a four-frequency pilot control blade type and has a cue (CUE) trunk separate from a video trunk. This relates to continuous shooting of recording and reproducing devices.

[Prior art]

Prior to the explanation, first, a tape running control method using pilot signals will be briefly explained.

FIG. 1 is a diagram showing video tracks formed on a boron tape T so as to be inclined in the longitudinal direction of the tape T, and a pilot signal recorded on each video track in a superimposed manner with a video signal. be. Arrow a indicates the tape running direction (forward direction).

In the figure, video trunk F1. F2. F3, F4
are fl, F2., respectively. F3. This indicates that the pilot signal of frequency F4 is recorded. The relationship is 1fl-filΣ1f3-f41'=fa, 1fl-
f41=lf2-f31=fb (However, fa≠fb is satisfied.) Here, for example, when the magnetic head 10 is tracking the video track F1 on the magnetic tape T as shown in FIG. Considering, the magnetic head 10
In addition to the pilot signal with the frequency f1 superimposed on the video trunk F1, the pilot signal component detected by ) is also included at the same time. The magnitude of the biloft signals detected from these adjacent tracks increases as the positional deviation from the center of the trunk being tracked by the magnetic head 10 increases.

As a result, the above-mentioned magnitudes of 1f2-fil and 1f4-fil are converted into voltages, and the direction of the trunk shift of the magnetic head IO is detected based on the magnitude, and the amount of the shift is detected from the difference component. These detected error components are fed back to a signal/water circuit (not shown) to control the running of the magnetic tape T.

FIG. 2 is an overall configuration diagram showing clearly the configuration of an example of connecting operation using this pilot signal control method.

In the figure, a pilot signal from a servo circuit 18 is superimposed on a video signal from a signal circuit 25 in a mixer circuit 24, and these are recorded on a video track by a video head 21 via a second changeover switch 26. Also,
During playback, the playback video signal and pilot signal are separated by a filter 23.

On the other hand, the control circuit 101 includes a reference pulse frequency generator 11
, gate circuit 12, first amplifier 13, first changeover switch 14, cue head 10, pulse number counting circuit 1
02 Furthermore, together with the servo circuit 18 and the like, when recording is stopped and the magnetic tape is transferred in the reverse direction from the time when the magnetic tape stops, including a temporary stop, the cue carrier F' 10 sends at least one pulse to the cue track. After recording a pulse train, it is configured as a means 105 for stopping and waiting or moving forward depending on the mode. Further, the control circuit 101 controls the cue head 1
0, the first changeover switch 14, the second amplifier 15, the waveform shaping circuit 16, the pulse count circuit 102, the servo circuit 18, etc., the magnetic tape is transferred in the forward direction by canceling the stop mode including a temporary stop. When it is done,
This device constitutes means 106 for reproducing the pulse train recorded on the cue track and restarting the recording operation when the number of reproduced pulses matches the number of pulses recorded on the cue track during reverse transport of the magnetic tape.

Next, an example of a magnetic recording/reproducing apparatus according to this configuration will be explained with reference to FIG. 3. In the figure, 10 is a cue head for recording and playback, 11 is a reference frequency generator, 12 is a gate circuit, 13 is a first amplifier, and 14 is a first changeover switch. After the reference pulse from 11 is amplified by the first amplifier 13 via the gate circuit 12, the reference pulse is passed through the first selector switch 14 for recording/reproducing switching.
The information is recorded on a queue trunk 50 (FIG. 4) on the magnetic tape T. The gate circuit 12 is connected to the tape T
Reference frequency generator 1 recorded on the cue trunk 50 of
This limits the number of pulses from 1.

15 is a second amplifier connected to the changeover switch 14 and amplifies the reproduced pulse signal of the cue track 50 during playback; 16 is a waveform shaping circuit connected to the second amplifier 15; and 17 is a control microcomputer. be. The microcomputer 17 has a second pulse count circuit 1
02, an input/output circuit 171, a timer memory 174, a timer 175, etc., and controls switching of the servo circuit 18 and the first changeover switch 26.

19 is a capstan motor, 20 is a reel motor, 21
is a video head, and this video head 21 is attached to a rotating drum 21a.

22 is a third amplifier, 23 is a filter, 24 is a mixer circuit, 25 is a signal circuit, and 26 is a second changeover switch connected to the video head 21. During recording, the video signal from the signal circuit 25 is A pilot signal from the servo circuit 18 is superimposed by a mixer circuit 24, and this is recorded on the video track on the magnetic tape T via the changeover switch 26. Also, during playback, a third amplifier 22 The reproduced signal is input to the filter 23 via the filter 23, and the video signal and the pilot signal are separated into a signal circuit 25 and a servo circuit 1, respectively.
The reproduction signal is sent to 8.

27 is an input terminal for a pause signal, 28 is a video head 2
This is an input terminal for a head switching signal for the first switching timing.

Next, the basic operation of the above configuration will be explained.

Assuming that recording is currently in progress, there is a fourth
As shown in the figure (al), a pilot signal is circulated and recorded through the video head 21, superimposed on the video signal.

In this state, when a pause signal is input to the microcomputer 17 via the input terminal 27, the microcomputer 17 synchronizes with the switching of the head switching signal input to the input terminal 28, that is, the current After the recording of the video track being recorded is completed, a command is issued to the servo circuit 18 to reversely rotate the capstan motor 19 and reel motor 20, and at the same time, the timer memory 174 records the reverse transport amount of the tape T.
, and at the same time as starting the timer 175, the magnetic tape T is transported backward in the direction indicated by the arrow.

At the same time, the microcomputer 17 opens the gate of the gate circuit 12 and opens the first φ conversion switch 14.
After switching to the recording side and recording several pulses, for example, 3 pulses (60 Hz reference frequency) of the pulse signal from the reference frequency generator 11 on the cue track 50 with the cue head 10, the gate circuit 12 Gate circuit 12
close the gate. The microcomputer 17 counts these pulses. At this time, since the second changeover switch 26 is switched to the reproduction side, there is no recording by the video head 21.

While performing the above operations, when the magnetic tape T has been reversely transported by a certain amount, the microcomputer 17 starts the capstan motor 19. At the same time as issuing a rotation stop command to the reel motor 20, the first changeover switch 14 is switched to the playback side, and the process is temporarily stopped and a recording standby state is entered (FIG. 4 (bl)).

Next, when the temporary stop is released, the servo circuit 18 rotates the capstan motor 19 and the reel motor 20 in the forward direction to transport the magnetic tape T in the forward direction (direction of arrow a in the figure). The pilot signal superimposed on the magnetic tape T is extracted via the video head 21, the third amplifier 22, and the filter 23, and the circulating pilot signal and frequency (for example, fl on the magnetic tape T and the frequency to be recorded) are extracted. The tape travel is controlled via the capstan motor 19 so that the phase and phase of the tape coincide with each other.

Furthermore, at the same time, the cue head 10 reproduces the pulse train 51 recorded on the cue track 50 on the magnetic tape T (FIG. 4(C)). This regenerated pulse train 51 is input to the microcomputer 17 through the second amplifier 15 and waveform shaping circuit 16, and the number of pulses is counted.

After that, the microcomputer 17
When the predetermined number of reproduced pulse trains from The changeover switch 26 of No. 2 is switched to the recording side.

As a result, the original recording operation is resumed, and the signal is recorded in the new video trunk 52.

The following operations are shown in the judgment and processing steps of flowcharts 80 to 95 in FIG.

The above configuration is for a recording-pause→recording operation, and the tape's reverse phase start point is the last recorded track position. However, in stop mode recording, there is a low possibility that the position of the video head after loading is completed will necessarily match the final track previously recorded on the tape, and continuous shooting in such a case is not reliable.

[Summary of the invention]

This invention has been made in view of the above, and detects the envelope of the video signal obtained from the video track on the tape during tape reverse transport to detect the last track on the tape, and from that point on, continuous recording is performed. It is an object of the present invention to provide a magnetic recording/reproducing device which can perform continuous operation with less overwriting even when transitioning from a stop mode to recording by performing this operation.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 shows a configuration according to an embodiment of the present invention. In the figure, 200 is a detection circuit, which corresponds to the video head 21.
After detecting the component of the video signal separated by the filter 23 from the reproduced signal obtained through the filter 23 using a detection method having a time constant with a fast rise and a slow fall, an envelope signal is extracted. A comparator 201 compares the output of the detection circuit [i'& 200 with a certain reference voltage and inputs an enveloped signal to the microcomputer 17.

Next, the operation will be explained.

Now, let us consider the case where the stop mode is shifted to the recording mode and a recording operation is performed.

In this operation, after the loading of the tape T is completed, it is assumed that the relative relationship between the video trunk previously recorded on the tape T and the video head 21 is as shown in FIG. 6+al. Here, in the figure, 220 indicates the position of the video head 21 with respect to the tape T. If you perform the same continuous shooting operation as in the past in this state, there will always be a blank zone between the final position of the video track and the video head 21, so continuous shooting will be impossible. However, according to this embodiment, this Even in such cases, it is possible to perform tethering operations.

From now on, the schematic diagram in Figure 5, the diagram in Figure 6, the operation explanatory diagram in Figure 6,
The continuous shooting operation in the state shown in FIG. 6+8) will be explained using the flowcharts shown in FIGS.

In the state shown in FIG. 6 (al), no reproduction output is obtained from the video head 2I.
is the detection circuit 200. Since the signal with envelope is not received from the comparator 201, it is determined that the video head 2I is not on-track to the video track recorded on tape T (processing step 251), and until a signal with envelope i is obtained. capstan motor 1
Outputs a reverse rotation command to the 9° reel motor 20 and rotates the tape T.
is transported back at a certain speed (processing step 255).
.

However, in consideration of new tapes, etc., in order to avoid unlimited reverse transport, a timer time of 2 seconds is set in the timer memory 174 in the microcomputer 17 to control the amount of reverse transport of the tape T. setting (processing step 254). Therefore, if the comparator 201 does not input a signal with an envelope signal to the microcomputer 17 even if the tape T is transferred backwards for 2 seconds, it is determined that there has been no previous recording within this range on the tape T. (Judgment step 256), without performing a continuous shooting operation, immediately outputs a forward rotation command to the capstan motor 19 and reel motor 20, and a recording side switching command to the second changeover switch 26 to start recording. Operation is entered (processing steps 257, 258). Needless to say, no tethering manipulation is performed in this case.

Meanwhile, while the tape T is being transported backwards, the microcomputer 17
When the video head 21 is placed on the recording trunk above the tape T while the memory memo U 174 is being subtracted by the operation of the memory recorder 175 in the tape T, some playback signal is obtained. For this reason, the detection circuit 200. An enveloped signal is manually input to the microcomputer 17 via the comparator 201.

An example of this state is shown in FIG. 6(C).

(in the same figure) is video head 2 on the recording trunk on tape T.
Example when 1 is on track (position indicated by 221 in the figure)
, (C) in the figure shows the reproduced signal at that time, and +d+ in the figure shows the state of the output of the comparator 201, respectively.

The microcomputer 17, which receives the envelope presence signal from the comparator 201, determines that the final position of the previously recorded video trunk has been detected (judgment step 251), and from then on, the same as the recording-pause state image is used. Continuous shooting operation (steps 82 to 95 in Figure 7)
(See P in Figures 7 and 8).

However, in this case, the tape T is temporarily stopped after being transferred backwards (
There is no standby state), and the tethering operations are performed continuously.

According to the apparatus of this embodiment, when transitioning from stop mode to recording, the last track on the magnetic tape is detected and the continuous shooting operation is performed from that point on, so that after the tape has been loaded, It is possible to absorb variations in the relative position of the video head and the final trunk previously recorded on the acid tape, making it possible to splice shots with extremely little overwriting.

Note that in the above embodiment, the queue (CUE) is
) I tried to record 3 pulses of 60Hz on the rack, but this is a maximum of 4Th 1111i1 at any frequency.
A higher pulse is fine.

Further, in order to detect the last track recorded on the tape in the stop-record mode, the tape reverse transport was set to 2 seconds, but this time can be freely selected according to the system.

Furthermore, when tape is transferred backwards, the video signal component of the playback signal is used to obtain the envelope signal, but it is also possible to use only the biloft signal component or the original playback signal that is a combination of both. good.

〔Effect of the invention〕

As described above, according to the magnetic recording and reproducing apparatus according to the present invention, in the splicing operation when transitioning from stop mode to recording, the last trunk on the tape is detected during reverse transport of the magnetic tape, and the splicing is performed from that point on. Since the recording operation is performed, it is possible to absorb variations in the relative position of the video head after loading is completed and the previously recorded final track, and the effect is that the connection operation can be performed reliably with less overwriting. There is.

[Brief explanation of the drawing]

Figure 1 is a diagram schematically showing the recording state of a magnetic tape in a pilot signal control type magnetic recording/reproducing device.
3 is a schematic block diagram illustrating an example of a conventional magnetic recording and reproducing apparatus using the continuous recording method shown in FIG. 2. Figures +a) to ldl are diagrams for explaining the continuous shooting operation in a conventional device, and FIG. 5 is a schematic block diagram of a magnetic recording and reproducing device according to an embodiment of the present invention.
FIG. 6 is a diagram for explaining the operation of the apparatus, FIG. 7 is a flowchart showing the operation procedure of conventional continuous shooting, and FIG. 8 is a flowchart diagram showing the operation procedure of an embodiment of the present invention. . 10... Cue track, 11... Reference frequency generator, 12... Gate circuit, 13... First amplifier,
14... First changeover switch, 15... Second amplifier, 16... Waveform shaping circuit, 17... Microconverter, 18... Servo circuit, 19... Capstan motor , 2... Reel motor, 21... Video head, 22... Third amplifier, 23... Filter, 24... Bex circuit, 25... Signal circuit, 50...
・Cue track, 51...Pulse train, 102...
Pulse number counting circuit, 105... Pulse train recording means, 200... Detection circuit, 201... Comparator,
a... Tape forward running direction, b... Tape backward running direction, T... Magnetic tape. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa Figure 1 Figure 4-52 Go to 01 Figure 8 Procedural amendment (voluntary) October 9, 1980 1. Indication of the case Patent application No. 1985-109851 2. Name of the invention Magnetic Recording and reproducing device 3, Representative Hitoshi Katayama of the person making the amendment (5) Column 6 of the detailed explanation of the invention in the specification subject to the amendment, Contents of the amendment (11 Specification, page 16, line 20) "When transferring one tape" should be corrected to "When transferring tapes backwards."

Claims (1)

[Claims] (1) In a magnetic recording and reproducing apparatus that superimposes a plurality of pilot signals having different frequencies on a video signal and records the same on a video trunk on a magnetic tape, and controls the running of the magnetic tape based on the pilot signals during playback, When recording is stopped and the magnetic tape is moved backward by a predetermined amount from the point where the magnetic tape stops, including a temporary stop, at least 14 I! Reverse direction transfer/pulse train recording means for recording a pulse train consisting of the above pulses, forward direction transport means for stopping and waiting or transporting the magnetic tape in the forward direction depending on the mode after recording the pulse train, and stopping including a temporary stop. When the magnetic tape is transferred in the forward direction when the mode is released, the pilot signal recorded on the magnetic tape and the pilot signal to be newly recorded are matched in frequency and phase with the upper Ayu magnetic tape. At the same time as controlling the running of the magnetic tape, the pulse train recorded on the cue track of the magnetic tape is reproduced, and at the point when the number of reproduced pulses matches the number of pulses recorded on the cue track during the reverse transport of the yuki tape. A magnetic recording and reproducing apparatus comprising a recording start means for starting a recording operation, wherein in the process of transitioning from the stop mode of the magnetic tape to the direct recording mode and restarting recording, the reverse direction transfer/pulse train recording means After detecting the last trunk recorded on the magnetic tape during reverse transport of the magnetic tape, the forward transport means records a pulse train in the cue trunk from that point on, and the forward transport means immediately detects the last trunk recorded on the magnetic tape after the predetermined amount of reverse transport. The magnetic tape is configured to be transported in a forward direction, and if the backward transport/pulse train recording means cannot detect the last recording track on the magnetic tape after the tape has been transported by a certain amount during the reverse transport of the magnetic tape, A special air recording and reproducing apparatus characterized in that said recording start means is configured to start recording immediately after said fixed amount of reverse transport.