JPH056247B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a magnetic recording/reproducing device, and more particularly to a magnetic recording/reproducing device that is improved so that the seams of images on a magnetic tape are not disturbed.

[Prior Art] Conventionally, in magnetic recording and reproducing apparatuses, there have been two methods for controlling the running of a magnetic tape: one using a control signal and the other using a pilot signal. First, the control signal control method will be explained.

FIG. 4 is a diagram showing the recording state of a magnetic tape recorded by a helical scan type magnetic recording/reproducing apparatus having a control track separate from a video signal track. In FIG. 4, video signal tracks 2 are generally recorded diagonally in units of one field on a magnetic tape 1, and control signals 3 are recorded at regular intervals in the tape running direction. This control signal 3 is used to control tape running so that the video signal magnetic head 5 can accurately scan the video signal track 2 during reproduction.

In the following explanation, the signal before being recorded on the magnetic tape 1 will be referred to as a recording control signal, the signal recorded on the magnetic tape 1 will be referred to as a control signal 3, and the signal reproduced from the magnetic tape 1 will be referred to as a reproduction control signal J. .

Normally, the control signal 3 is created by dividing the vertical synchronization signal of the video signal to be recorded by 1/2. Therefore, during playback, the control head 6
The magnetic tape 1 is adjusted so that the time when the control signal 3 is detected by the video signal magnetic head 5 coincides with the time when the video signal magnetic head 5 comes near the starting end of the video signal track 2 (that is, the part where the vertical synchronizing signal is recorded). The driving condition is controlled.

By the way, if the magnetic tape 1 is temporarily stopped at an arbitrary time during recording and then restarted at an arbitrary timing and starts recording immediately, the recording phase of the video signal track 2 may differ at the joint, or the video signal may be different. Since the inclination angle of the signal track 2 changes, there is a problem in that the reproduced image of that part becomes distorted. For example, magnetic tape 1
When the video signal magnetic head 5 is paused,
The traveling locus of the vehicle becomes as shown by the dotted line 4 in FIG.
In order to prevent such disturbances at the joints of images, the following operations are performed in the servo control system.

If a pause command is issued during recording, the recording operation is immediately stopped and the magnetic tape 1 is moved a certain amount in the opposite direction. At that point, the transfer of the magnetic tape 1 is stopped and the recording standby state is entered.

Thereafter, when the temporary stop command is released, the magnetic tape 1 starts to be transferred in the forward direction. At this time, the recording operation is not started immediately, but the control signal J reproduced from the control track of the magnetic tape 1 is synchronized with the vertical synchronization signal that serves as a reference for the video signal to be newly recorded. That is, after matching the phase of the previously recorded video signal track with the phase of the video signal track to be newly recorded, the recording mode is switched and the switching operation is restarted. In this way, continuous shooting is performed so that the connection between the previously recorded image and the newly recorded image is not disturbed.

Next, a 4f pilot signal control method will be described as an example of a method using a pilot signal.

FIG. 5 is a diagram showing the relationship between video signal tracks formed on the magnetic tape 7 so as to be inclined in the longitudinal direction of the tape, and pilot signals recorded on each video signal track in a superimposed manner with the video signal. .
In FIG. 5, video signal tracks F ₁ , F ₂ , F ₃ ,
_F4 indicates that pilot signals of frequencies ₁ , ₂ , ₃ , and ₄ are recorded in a superimposed manner. These frequencies are | ₂ − ₁ | | ₃ − ₄
|= _a , | ₁ − ₄ | | ₂ − ₃ |= _b , _a ≠ _b
Satisfied with the relationship.

Here, for example, as shown in FIG. 5, the magnetic head 8 tracks the video signal track F ₁ on the magnetic tape 7.
When tracking a video signal, the pilot signal component detected by the magnetic head 8 includes, in addition to the pilot signal of frequency f ₁ superimposed on the video signal track F ₁ , the side lead effect and the cross. Pilot signals superimposed on both adjacent tracks (F ₂ and F ₄ in the example of FIG. 5) due to talk etc. are also included at the same time. The magnitude of the pilot signals detected from these adjacent tracks increases as the positional deviation from the center of the video signal track being tracked by the magnetic head 8 increases. As a result, | ₂
− ₁ |, | ₄ − ₁ | are converted into voltages, the direction of positional deviation from the center of the video signal track is detected based on the magnitude, and the amount of positional deviation from the center of the video signal track is detected using the difference component. To detect. These detected error components are fed back to the servo control system to control the running of the magnetic tape.

[Problems to be Solved by the Invention] Incidentally, the above-mentioned magnetic recording and reproducing apparatus using the pilot signal control method has a drawback in that it is not provided with a function that allows continuous shooting to prevent the joints of images from being disturbed.

Therefore, the main object of the present invention is to provide an improved magnetic recording and reproducing device that can perform continuous shooting without disturbing the joints of images when transitioning from recording mode to pause mode and then to recording mode. That's true.

[Means for Solving the Problems] The present invention converts four pilot signals, first, second, third and fourth, having different frequencies, into a video signal to be recorded in synchronization with the rotation of a rotating magnetic head. In a magnetic recording and reproducing apparatus that sequentially records and reproduces multiplexed data on a magnetic tape, in a recording mode, a tape running control means moves the magnetic tape in a forward direction based on a forward transport signal generated from a forward transport signal generating means. Transport. Then, when paused,
While transporting the magnetic tape in the forward direction, at least one pulse signal to be recorded on a cue track provided separately from a video signal recording track is generated from a cue pulse generating means and recorded on the cue track by a cue head. After recording the pulse signal on the cue track, the recording control means stops the recording of the video signal by the video signal recording head, and the tape running control means, based on the reverse direction transport signal generated by the reverse direction transport signal generation means, The magnetic tape is transported in the opposite direction for a certain period of time. At this time, the number of pulse signals picked up from the cue head is counted by the first pulse counting means. In response to the magnetic tape being controlled to run in the forward direction at the time the pause is released,
The number of pulse signals picked up by the queue head is counted by the second pulse counting means, and when the counted value matches the counted value of the first pulse counting means, the recording operation is restarted.

[Operation] In the recording mode, the present invention records one or more cue pulses on the cue track while transporting the magnetic tape in the forward direction during pause.
The magnetic tape is transported in the reverse direction for a certain period of time, at this time the already recorded cue pulses are picked up and counted, and when the pause is released and recording is to be performed, the magnetic tape is transported in the forward direction. The pulses recorded on the cue track are picked up, and when the number matches the number of pulses picked up when the magnetic tape was transferred backwards, the recording operation is restarted.

[Embodiment] FIG. 1 is a schematic block diagram showing an embodiment of the present invention. First, the electrical configuration of an embodiment of the present invention will be described with reference to FIG. The signal circuit 25 outputs a video signal to be recorded on a magnetic tape, and the output of this signal circuit 25 is connected to the mixer circuit 24. The mixer circuit 24 mixes a pilot signal output from a servo circuit 18, which will be described later, and a video signal from a signal circuit 25. It is connected to the magnetic head 21. Signal circuit 25 and mixer circuit 2
4, the recording/reproducing switch 26, and the video signal magnetic head 21 constitute a video signal recording circuit.

The servo circuit 18 controls a capstan motor 19 and a reel motor 20 that control the running of the magnetic tape, and is connected to a mixer circuit 24.
During recording, the pilot signal outputted from the servo circuit 18 is superimposed on the video signal outputted from the signal circuit 25 by the mixer circuit 24, and the pilot signal outputted from the servo circuit 18 is superimposed on the video signal outputted from the signal circuit 25. The video signal is guided to the video signal magnetic head 21 and recorded on a video signal track on the magnetic tape.

The video signal magnetic head 21 is also connected to an amplifier 22 via a recording/reproducing switch 26. The output of amplifier 22 is connected to filter 23 . The filter 23 separates the video signal and the pilot signal, and supplies the pilot signal to the servo circuit 18 and the video signal to the signal circuit 25.
The video signal magnetic head 21, the recording/reproducing switch 26, the amplifier 22, the filter 23, and the signal circuit 25 constitute a video signal reproducing circuit. That is, during playback, the video signal and pilot signal picked up from the video signal track by the video signal magnetic head 21 are transferred to the recording/playback switch 2.
6 and is input to the amplifier 22 and amplified.
The output of the amplifier 22 is given to a filter 23, which separates the video signal and the pilot signal, and the pilot signal is sent to the servo circuit 1.
8, and the video signal is supplied to the signal circuit 25.

A reference frequency signal generator 11 generates pulses to be recorded on a cue track of a magnetic tape, and the output of this reference frequency signal generator 11 is connected to a gate circuit 12 and a microcomputer 17. This microcomputer 17 controls the entire operation of the magnetic recording/reproducing apparatus, and is constituted by, for example, a one-chip microcomputer in which a ROM, a RAM, and an input/output port are integrated. The gate circuit 12 gates the pulses generated from the reference frequency signal generator 11 to control the number of pulses to be recorded on the cue track. Therefore, a gate signal is given to the gate circuit 12 from the microcomputer 17. The output of gate circuit 12 is connected to amplifier 13.

The amplifier 13 amplifies the pulse, and
The output of this amplifier 13 is connected via a recording/reproducing switch 14 to a cue head 10 for both recording and reproducing. Therefore, the reference frequency signal generator 11, the gate circuit 12, the amplifier 13, and the recording/reproducing switch 1
4 and queue head 10 constitute a circuit for recording pulses on the queue track. Note that the microcomputer 17 counts the number of pulses generated from the reference frequency signal generator 11.

The queue head 10 is connected to the input of an amplifier 15 via a read/write switch 14. This amplifier 15 amplifies the pulses picked up from the magnetic tape by the queue head 10. The output of this amplifier 15 is connected to the input of a waveform shaping circuit 16. This waveform shaping circuit 16 shapes the waveform of the pulse amplified by the amplifier 15. The output of the waveform shaping circuit 16 is connected to a microcomputer 17. Therefore, the queue head 10, the recording/reproducing switch 14, the amplifier 15, and the waveform shaping circuit 16 constitute a circuit for reproducing the pulses recorded on the queue track.

Further, the microcomputer 17 is connected to a servo circuit 18, a recording/reproducing switch 14, and a recording/reproducing switch 26. The microcomputer 17 provides various command signals to a servo circuit 18 that controls the running of the magnetic tape, and outputs command signals for switching the recording/reproducing switch 14 and the recording/reproducing switch 26, respectively. In addition,
The microcomputer 17 has a temporary stop signal 27.
and head switching signal 28 are provided. The temporary stop signal is a toggle operation, and once the temporary stop signal is input, the temporary stop mode is set, and when the temporary stop signal is input again, the temporary stop mode is canceled. Note that the pulses generated from the reference frequency signal generator 11 are synchronized with the head switching signal 28.

FIG. 2 is a diagram showing the recording state of signals on a magnetic tape in order to explain the operation of one embodiment of the present invention shown in FIG. 1, and FIG. FIG.

Next, with reference to FIGS. 1 to 3, a specific operation of an embodiment of the present invention will be described.

Assuming that recording is currently in progress, pilot signals of frequencies ₁ , ₂ , ₃ , and ₄ are circulated on the magnetic tape 7, superimposed on the video signal, as shown in Figure 2a. It is recorded by the magnetic head 21. In this state, when the temporary stop signal 27 is input to the microcomputer 17, the microcomputer 17 determines whether or not the temporary stop signal 27 is input. Microcomputer 17
When it determines that the pause signal 27 has been input, it determines whether or not it is currently in the pause mode. If the mode is not the temporary stop mode, it is determined whether the polarity of the head switching signal 28 has been reversed. That is, after recording to the video signal track currently being recorded is completed, it is determined whether or not the next head switching signal 28 has been input.

When it is determined that the polarity of the head switching signal 28 has been reversed, that is, that the next head switching signal 28 has been input, a command signal for opening the gate is output to the gate circuit 12. Accordingly, gate circuit 1
2 opens the gate and supplies the pulse signal output from the reference frequency signal generator 11 to the amplifier 13.
At this time, the microcomputer 17 switches the recording/reproducing switch 14 to the recording side. The amplifier 13 applies the pulse output from the gate circuit 12 to the cue head 10 via the recording/reproducing switch 14. Queue head 10 records the pulse on queue track 50. In this embodiment, the reference frequency signal generator 11 has a reference frequency of 60Hz.
Assume that three pulses are generated and three of these pulses are recorded on the cue track.

The microcomputer 17 counts the pulses from the reference frequency signal generator 11 and
Determine whether or not you have become an individual. When it is determined that the number of recorded pulses has become three, gate circuit 1
A command signal is given to 2 to close the gate. Accordingly, the gate circuit 12 controls the reference frequency signal generator 1
When 1 to 3 pulses are output, the gate is closed. Then, the microcomputer 17 switches the recording/reproducing switches 14 and 26 to the reproducing side, respectively. With that, QUTRACK 5
Recording of pulses on the 0 and recording of video signals to the recording/reproducing switch are stopped. The magnetic tape in this state is as shown in FIG. 2b.

The microcomputer 17 starts measuring time using a transfer amount setting timer for the magnetic tape 7. Note that this reverse transfer amount setting timer is configured by a program. Furthermore, microcomputer 1
7 gives a command signal to the servo circuit 18 to rotate the capstan motor 19 and the reel motor 20 in opposite directions. In response, the servo circuit 18 rotates the capstan motor 19 and the reel motor 20 in the opposite direction to transport the magnetic tape 7 in the opposite direction. During the reverse transport of the magnetic tape 7, the recording/reproducing switches 14 and 26 are respectively switched to the reproducing side. When the magnetic tape 7 starts to be transferred in the reverse direction, the queue track 5 described above
The pulse signal recorded at
is applied to amplifier 15 via. An amplifier 15 amplifies the pulse signal and provides a waveform shaping circuit 16. The waveform shaping circuit 16 shapes the waveform of the pulse signal and supplies it to the microcomputer 17. The microcomputer 17 counts the number of pulse signals picked up after the magnetic tape 7 is transported in the reverse direction. Therefore, the microcomputer 17 constitutes the first pulse counting means.

The microcomputer 17 is QUTRACK 5.
The pulse signals picked up from 0 are counted, and it is determined whether the timer for setting the reverse transfer amount of the magnetic tape 7 has counted a predetermined time. If the predetermined time has elapsed, the capstan motor 19
And a command signal for stopping the rotation of the reel motor 20 is given to the servo circuit 18. depending on,
The servo circuit 18 stops the capstan motor 19 and the reel motor 20 from rotating in the opposite direction. At the same time, the microcomputer 17 stops counting the reproduction pulses from the queue track 50.

By carrying out the above-described operation, when the magnetic tape 7 has been transferred a certain amount in the opposite direction, the transfer of the magnetic tape 7 is stopped and the recording standby state is entered. The recording state on the magnetic tape 7 at this time is as shown in FIG. 2c. In addition, 51 shown in FIG. 2c shows the state of the pulses recorded on the cue track 50, which includes one previously recorded pulse and a newly recorded pulse when the pause signal 27 is input. This is a state in which three pulses, a total of four pulses, were counted.

Next, when the pause signal 27 is input again and the recording temporary standby state is canceled, the microcomputer 17 sends a command signal to the servo circuit to rotate the capstan motor 19 and the reel motor 20 in the forward direction. Give to 18. In response, the servo circuit 18 rotates the capstan motor 19 and the reel motor 20 in the forward direction to rotate the magnetic tape 7.
is transferred in the forward direction. At this time, the video signal magnetic head 21 picks up the pilot signal recorded on the magnetic tape 7 in a superimposed manner with the video signal, and supplies it to the amplifier 22 via the recording/reproducing switch 26. The amplifier 22 amplifies the picked up signal and supplies it to the filter 23. The filter 23 separates a pilot signal and a video signal from the picked up signal and supplies the pilot signal to the servo circuit 18. The servo circuit 18 adjusts the frequencies of the extracted pilot signal and the circulating pilot signal to be newly recorded, that is, for example, the frequency ₁ of the pilot signal on the magnetic tape 7, the frequency 1 of the pilot signal to be newly recorded, and the frequency ₁ of the pilot signal to be newly recorded. Controlling the rotational speed of the capstan motor 19 and the reel motor 20 so that the phases match each other,
The running of the magnetic tape 7 is thereby controlled. Furthermore, the pulse 5 recorded on the queue track 50 on the magnetic tape 7 by the queue head 10.
1 is picked up. This picked up pulse 51 is input to the microcomputer 17 via the recording/reproducing switch 14, the amplifier 15 and the waveform shaping circuit 16. The microcomputer 17 counts the number of regenerated second pulses. Therefore, the microcomputer 17 constitutes a second pulse counting means for counting the number of reproduced pulses. And microcomputer 1
7 determines whether or not this second number of pulses matches the count value obtained by counting the first number of pulses reproduced when the magnetic tape 7 is transferred in the reverse direction during the above-mentioned pause. do. The state on the magnetic tape 7 at this time is shown in FIG. 2d.

Thereafter, when the microcomputer 17 determines that the second number of pulses reproduced matches the first number of pulses when the magnetic tape 7 is transferred in the reverse direction, that is, after the pause signal 27 is input,
When the number of pulses 51 recorded on the cue track 50 becomes the same as the number of pulses counted during the reverse transport of the previous magnetic tape 7, the microcomputer 17 determines whether the polarity of the head switching signal 28 has been reversed or not. to decide. When it is determined that the polarity of the head switching signal 28 has been reversed, the recording/reproducing switch 26 is switched to the recording side in synchronization with this. The recording state on the magnetic tape 7 at this time is shown in FIG. 2e.
Reference numeral 52 shown in FIG. 2e indicates the appearance of a newly recorded video signal track. Through this series of operations, the original recording operation is resumed.

Note that the constant amount when the magnetic tape 7 is transferred in the reverse direction is at least equal to the pilot signal recorded in a superimposed manner on the magnetic tape 7 when the magnetic tape 7 is transferred in the forward direction after the pause is released. The time required to match the frequency and phase of a pilot signal to be newly recorded is expressed by the length of the magnetic tape 7.

Further, in the above-described embodiment, the case where previously recorded pulses remain on the cue track was explained as an example, but the same operation can be performed using only newly recorded pulses.

Furthermore, in the embodiment described above, the queue track 5
Although the number of pulses to be recorded on 0 is three pulses with a frequency of 60 Hz, it may be at least one pulse with any frequency, and the frequency and number of pulses may be freely selected according to the apparatus.

Further, in the above-described embodiment, if the number of pulses and the duty ratio of the pulses recorded on the cue track are adjusted, the recorded pulses can be used for cueing, etc.

[Effects of the Invention] As described above, according to the present invention, when the magnetic tape is transferred a certain amount in the forward direction during recording, one or more pulses are recorded on the cue track provided separately from the video signal track. Then, the magnetic tape is transferred in the reverse direction for a certain period of time, the number of pulses of the cue track picked up by the cue head is counted at that time, and the pause is released and the magnetic tape is transferred in the forward direction for recording. When,
The pulses recorded on the cue track are counted again, and the recording operation is restarted when the counted value becomes the same as the number of pulses counted during reverse direction transport. You can perform continuous shooting.
In particular, with this invention, when taking pictures with a camera, it is possible to perform continuous shooting without disrupting the seams even when repeating recording -> pausing -> recording, which is frequently used in a short period of time.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram showing one embodiment of the present invention. FIG. 2 is a diagram showing a recording state on a magnetic tape for explaining the operation of the embodiment shown in FIG. FIG. 3 is a flow diagram for explaining the operation of the embodiment shown in FIG. FIG. 4 is a diagram showing the recording state of a magnetic tape recorded by a magnetic recording/reproducing apparatus using a conventional control signal control system. FIG. 5 is a diagram showing the recording state of a magnetic tape recorded by the pilot signal control type magnetic recording/reproducing apparatus utilized in the present invention. In the figure, 7 is a magnetic tape, 10 is a queue head, 11 is a reference frequency signal generator, 12 is a gate circuit, 13 and 15 are amplifiers, 14 is a recording/reproducing switch, 16 is a waveform shaping circuit, 17 is a microcomputer, and 18 is a servo circuit, 19 is a capstan motor, 20 is a reel motor, 26 is a recording/reproduction switch, 27 is a pause signal, 28 is a head switching signal, 50 is a queue track, and 51 is a pulse recorded on the queue track. .

Claims (1)

[Claims] 1. Four pilot signals, first, second, third, and fourth, having different frequencies, are multiplexed onto a video signal to be recorded in synchronization with the rotation of a rotating magnetic head, and are recorded on a magnetic tape. In a magnetic recording and reproducing apparatus that sequentially records and reproduces data, in a pause mode, a cue pulse generator generates at least one pulse signal to be recorded on a cue track provided separately from a video signal recording track on the magnetic tape. means, a queue head for recording and reproducing pulse signals generated from the queue pulse generation means on the queue track; and a forward direction transport signal for transporting the magnetic tape in the forward direction in the recording mode and the pause release mode. a forward direction transport signal generating means for generating a backward transport signal for transporting the magnetic tape in the reverse direction for a predetermined period of time in response to a pulse signal being recorded on the cue track by the cue head; transport signal generating means for transporting the magnetic tape in the forward direction in response to a forward transport signal from the forward transport signal generating means; tape travel control means for transporting the magnetic tape in a reverse direction for a predetermined period of time; the tape travel control means starts transporting the magnetic tape in the reverse direction based on a reverse transport signal from the reverse transport signal generating means; a first pulse counting means for counting the number of pulse signals picked up by the cue head; after recording at least one pulse signal on the cue track by the cue head, recording of the video signal by the video signal recording head; recording control means for stopping recording; at the time of release of the temporary stop, the tape running control means starts transporting the magnetic tape in the forward direction based on a forward transport signal from the forward transport signal generating means; a second pulse counting means for counting the number of pulse signals picked up by the cue head, and a count value of the second pulse counting means is equal to the number of pulse signals picked up by the cue head;
A magnetic recording/reproducing device comprising means for restarting recording operation when the count value of the pulse counting means matches the count value of the pulse counting means.