JPS5916478A - Intermittent recorder - Google Patents

Abstract

PURPOSE:To attain accurate recording on a tape without control pulse, by using a signal having a frequency proportional to the rotation of a capstan as a reference phase signal, and recording a video signal on the tape only at the period when the tape is not stopped rapidly. CONSTITUTION:A monostable multivibrator 11 is triggered with a head changeover pulse and synchronized between the rotating phase of a rotating disc and a vertical synchronizing section of a recording video signal. A monostable multivibrator 12 is triggered with an output of the monostable multivibrator 11 and the inverting time is controlled with a framing pulse P2. A monostable multivibrator 13 is triggered with an output of the monostable multivibrator 12 and a driving pulse is applied to a capstan motor driving circuit 16. When an FG pulse is obtained from a rotating frequency detector 18 in driving the tape from the circuit 16, the pulse is applied to the circuit 16 as a brake pulse P4 to stop the tape.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is a video tape recorder (hereinafter referred to as a VTR) in which a video signal is recorded on a magnetic tape suitable for intermittent playback, so-called frame-by-frame playback. The present invention relates to an intermittent recording device capable of recording.

[Technical background of the invention]

In VTRs, intermittent playback is used, for example, when you want to grasp long-term image content in a short time.
So-called frame-by-frame playback is possible. Conventionally, this frame-by-frame advance 1 ↓] Raw images are produced by sequentially repeating two operations: stopping the magnetic tape and playing still images, and running the magnetic tape at high speed and not playing images during this period. It was made to reoccur intermittently. .

However, in this method, the video head accurately tracks the recording track by suddenly bringing the magnetic tape from a stopped state to a high-speed feeding state, and then suddenly stopping the magnetic tape, which is running at high speed, at a desired position. Because it is necessary to drive and cut the magnetic tape so that it can be
This had the disadvantage that the magnetic tape drive mechanism during frame-by-frame playback was complicated. Moreover, there are technical limitations in controlling a magnetic tape that is being fed at high speed so that it suddenly stops at a predetermined position, and there is a drawback that noise inevitably appears in reproduced images.

In addition, if intermittent image information is sufficient, such as when you want to know the state of gradual changes in movement over a long period of time, it is necessary to record and remove image information for the entire operation period on magnetic tape. First, there was a drawback that the magnetic tape was used more frequently.

Furthermore, if you want to record different contents frame by frame on a magnetic tape and use the magnetic tape as a file, for example, you will have to repeat the recording and stopping operations of the video tape recorder each time you change the recorded content. However, it had the disadvantage of being complicated to operate.

The applicant of this patent has proposed an intermittent recording device which solves the above-mentioned drawbacks in Japanese Patent Application No. 56-107671 and Japanese Patent Application No. 56-107-
It was proposed in No. 107672. Talent, special +1J 5th year of Showa
In No. 6-107671, the magnetic tape in a stopped state is rapidly run in accordance with the rotational phase of the video head, and when a track for two fields is formed, the magnetic tape is also rapidly run in accordance with the rotational phase of the video head. We have proposed an intermittent recording device that can obtain frame-by-frame images during normal playback by recording a control signal only when the tape is running or stopped. In addition, in Special No. 56-107672, a magnetic tape on which a control signal is recorded is used, the magnetic tape is rapidly run in accordance with the rotational phase of a video head, and then the playback signal of the control signal is An intermittent recording device that can obtain a frame-by-frame playback 1lII image during normal playback by suddenly stopping the tape using the base phase signal as a basic thread phase signal and recording a video signal for a predetermined field P on the tape during the tape running period. provided.

[Problems of the Background Art J] By the way, in Japanese Patent Application No. 107,671/1983, when stopping the tape, the tape drive (p):' is appropriately delayed to obtain a pre-knee radius for stopping the tape.

Therefore, the timing of stopping the tape could not be said to be accurate. Furthermore, in Japanese Patent Application No. 107,672/1984, the control signal is used as a reference to stop the tape, so the timing of the stop is accurate, but it has the disadvantage that only a tape on which a control signal has been recorded in advance can be used for one cycle. .

[Purpose of the invention]

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide an intermittent recording device that can accurately perform intermittent recording at equal intervals even on a tape on which no control pulse has been recorded in advance.

[Summary of the invention]

Honkai Mei is equipped with a video head that records video signals on magnetic tape, a rotation frequency detector that picks up a signal with a frequency proportional to the rotation of the capstan that drives the tape, and a rotation frequency detector that detects the magnetic tape when it is in a stopped state. A l1ff tape drive hand that repeats the operation of rapidly causing the magnetic tape to run in accordance with the rotational phase and abruptly stopping the magnetic tape using the signal from the rotational frequency detector as a reference phase signal, and this magnetic tape drive means. The present invention attempts to obtain frame-by-frame images during playback using an intermittent recording device equipped with means for recording video signals on a magnetic tape only during the period when the tape is running.

[Embodiments of the invention]

Hereinafter, the present invention will be explained based on an illustrated embodiment.

FIG. 1 is a circuit diagram showing a magnetic tape drive means.

In this figure, 11 to 15 are first to fifth monostable multivibrators MM, 16 is a capstan motor drive circuit, and 17 is a capstan motor. 18 is a rotation sphere wave number detector that can obtain a signal with a frequency proportional to the rotation of the capstan, and 29 during normal playback.
．． A signal with a frequency of 97 Hz (hereinafter referred to as p Q /IP pulse) can be obtained. Specifically, this may be achieved by, for example, attaching a tack plate having teeth on the outside and inside to the capstan flywheel, and attaching the FG coil with a slight gap in the direction of the capstan axis. Due to the capstan rotation, a signal with a frequency proportional to the rotation speed is obtained from the FG coil. 19 is this F
G This is an amplifier that amplifies noise.

The monostable multivibrator 11 is triggered by the head switching noculus P shown in FIG. P is approximately 1 on the rotating disk.
801 Turning on two video heads spaced apart;
This is a pulse for switching off, and is synchronized with the rotational phase of the rotating disk and the vertical synchronization part of the recording video signal. What is the output of monostable multivibrator 11? It is used to obtain the timing of the rise of the drive/4' pulse described in i. The monostable multivibrator 12 is triggered by the output of the monostable multivibrator 11' and lags behind the output of the monostable multivibrator 11 by about...
Derive the mother Luz. This monostable multi-nogulator 1
Reference numeral 2 is a non-pulling type multivibrator, and the separately supplied frame-by-frame feed pulse P and reverse reversal time are controlled. Immediately after returning from the inverted state to the original state, the output pulse of the monostable multivibrator 11 causes the inverted state again. In this case, the period of the output pulse of the monostable multivibrator 12 is set to an integral multiple of the period of the output pulse of the monostable multivibrator 11, that is, the period of the head switching pulse P.

The monostable multivibrator 13 is triggered by the output pulse of the monostable multivibrator 12, and derives a pulse P, whose phase is delayed from the output pulse of the monostable multivibrator 12 (see FIG. 2(b)). . This pulse P3 is supplied to the capstan motor drive circuit 16 as a drive pulse for running the magnetic tape. Is this driving force P, the output J of the monostable multivibrator 11? The period is the output of monostable multivibrator 12 J? ) Response cycle,! : −
i do When the drive pulse pH is derived, the capstan motor drive circuit 16 generates a drive pulse A which is approximately equal to the drive pulse P3.
A voltage having a pulse width of 1 and an appropriate amplitude level is generated, and this voltage is applied to the ten terminals of the capstan motor 17 to suddenly run the magnetic tape at approximately the normal reproduction speed.

At this time, the video signal and control signal are recorded on the magnetic tape, details of which will be described later. In order to match the rotational phase of the video head and the timing of tape running, the inversion synchronization of the monostable multi-novel breaker 11, that is, the delay, must be adjusted appropriately. Approximately two recording tracks are formed during the period -.

When the video signals for two fields have been recorded in this way, the capstan motor 17 is divided into 16 circuits per drive circuit to stop the magnetic tape. For this purpose, the pre-kino f) is derived by a Resslema monostable multivibrator 15.

That is, when the magnetic tape runs, the rotational frequency detector 18 detects F G /4' (see Fig. 2) during the running of the magnetic tape.
C) is obtained. This l'Q+rus is amplifier 1
9, the monostable multivibrator 14 is amplified by this output (see FIG. 2(d)), and a pulse is derived from the monostable multivibrator 14. The monostable multivibrator 15 is triggered by the output pulse of the monostable multivibrator 14, and derives a phase shifted signal from this output pulse. This pulse is supplied to the capstan motor drive circuit 16 as a brake pulse Pi (see tel in the fJZ diagram) for stopping the magnetic tape. As a result, the capstan motor drive circuit 16 applies a voltage having a pulse width approximately equal to the brake pulse P4 and an appropriate amplitude level to one terminal of the capstan motor 17, thereby abruptly stopping the magnetic tape. . During this stop period, no video signal or control signal is recorded. −
FIG. 2(f) shows the stopping and running states of the magnetic tape,
The vertical axis indicates the tape running distance X, for example, in terms of the number of recording tracks,
The horizontal axis indicates time t, for example, in terms of the number of fields. The period B is the period when the magnetic tape is stopped, and the period B is the period when the magnetic tape is running.

In order to match the running start timing of the magnetic tape with the rotational phase of the video head, the inversion period of the monostable multi-pie break 11, that is, the amount of delay, may be adjusted as appropriate. This is because both the rotational phase of the video head and the head switching pitch P are synchronized with the vertical synchronization signal of the recording video signal. Therefore, in the circuit shown in FIG. 1, the head switching pulse P1 is appropriately delayed to obtain the running start timing of the magnetic tape. Therefore, by appropriately adjusting the amount of delay, the running start timing of the magnetic tape and the rotational phase of the video spatula V can be adjusted. This allows the timing to be set to the optimum state.

Furthermore, in order to stop the magnetic tape at the timing when two recording tracks are formed, the delay amount of the monostable multivibrator 14 may be adjusted as appropriate.

Further, the time from the start of one run of the magnetic tape to the start of the next run, in other words, the intermittent recording speed, is appropriately set by changing the delay amount of the monostable multivibrator 12.

As explained above, if the magnetic tape is driven by the circuit shown in FIG.
It moves while repeatedly stopping, and video signals and control signals are recorded only when it is running.

FIG. 4 shows an example of a specific circuit W4ri5 of the capstan motor drive circuit 16. In the illustrated capstan motor drive circuit 16, when the dry voltage 9 pulse P3 is supplied, the transistors 161 and 162 are turned on, and a voltage of a predetermined amplitude level is applied to the terminal 171 of the capstan motor 17 to start the motor. Rotate it forward. On the other hand, when the brake pulse P4 is applied, the transistors 16J, , 164 are turned on, and tW of a predetermined amplitude level is applied to one terminal 172 of the capstan motor 17, causing the capstan motor 17 to rotate in the reverse direction. . In the figure, 165°166 is a resistance, and 10B is xis.

Next, the video signal recording means and the control signal recording means will be explained. In FIG. 5, 21 is a video signal processing circuit, 22 is a rotary transformer,
23 is a video head. The portion described above is a video signal recording thread circuit provided in a video tape recorder, and has a common configuration. Further, 24 is a counter that counts down the vertical synchronization signal or the oscillation output of a 5QHz oscillator (not shown) to 1/2;
25 is an amplifier, and 26 is a control spatula. The portion described above is a recording system circuit for a video signal provided in a video tape recorder, and has a general configuration.

Reference numeral 27 denotes a switching transistor, which is in an off state while the magnetic tape is in a running state, and on the other hand, is in an off state during a period of 4υ1 when the magnetic tape is in a stopped state, so that the video signal processing circuit 2
Shunt the output of 1 to the ground side. As a result, a video signal is recorded on the magnetic tape only while the magnetic tape is running. 28 is also a switching transistor, and like the switching transistor 27, the transistor 1 is designed to be in an off state only while the magnetic tape is running.
It will be till rall. As a result, control signals are recorded on the magnetic tape only while the magnetic tape is running.

Switching transistors 27 and 28 are turned on.

The control signal for turning off and opening is obtained by the R-8 flip-flop 29 and the D flip-flop 30. Here, the operations of the video signal recording means and control signal recording means having the above configuration are shown in FIGS. 6(a) to (h). ) is explained by Kerr et al. with reference to the timing chart.

Drive before, during and after tape running/J Luz P3, PlayKino J? ) The timing of response P4 and head switching pulse P is shown in FIG. 6 (al, (bl).

As shown by tci,<d*, K is reached, and a suppressing signal is required to turn off the switching transistors 21 and 28 only during the period from time t to time t. To do this, first, the R-87 lip-flop 29 shown in FIG. , the driving pulse P is inverted and supplied to the R-8717 flip-flop 29 as shown in FIG. The output pulse of this R-8 flip-flop 31 is shown in FIG. A forward switching pulse P is supplied to the clock terminal CP.Therefore, the D flip-flop 30 can operate only during the period when the pulse is output from the R-f3 flip-flop 29, and the non-inverting output terminal of the D flip-flop 30 is enabled to operate. ) (see Fig. 6(f)), and this is supplied as a control signal to the pace of the switching transistor 27.211 described above.As a result, the switching transistor 27.21J is activated to prevent the magnetic tape from running. The video signal and control signal are recorded on the magnetic tape only during this period.
g) shows the control signal outputted from the 1/2 counter 24, and FIG. Therefore, control signals as shown in FIG. 6(h) are continuously formed on the magnetic tape.Therefore, according to the configuration shown in FIG. It can be said that the control signal is recorded as a negative polarity i4 pulse in the synchronization section.-According to this embodiment detailed above, even a tape on which no control signal is recorded can be fed intermittently at accurate intervals. Naturally, the effect described in the specification previously filed by the present applicant can also be obtained.In other words, the tape pattern of the recorded magnetic tape is exactly the same as the chisino and turn during normal recording. Frame-by-frame playback can be performed in exactly the same way as for frame-by-frame playback, so the magnetic tape drive mechanism during frame-by-frame playback does not become complicated at all.Furthermore, the magnetic tape drive mechanism is similar to that of an intermittent slow playback device. Since the configuration is substantially the same, there is no complication, and video signals and control signals can be recorded accurately.

Also, since intermittent video signals can be recorded on magnetic tape in a continuous recording track, less magnetic tape can be used to record video signals over long periods of time. . Furthermore, the video signal can be accurately recorded using the same tape pattern as that used for normal recording, as described above, and can be played back in the same way as normal playback, resulting in clear frame-by-frame playback. A reproduced image can be obtained.

Therefore, for example, slow movements over a long period of time can be seen in clear images in a short period of time. In addition, when using magnetic tape as a file, there is no need to operate the video tape recorder each time the recorded content changes, making the operation easier when recording different content frame by frame. .

Further, by changing the stop time of the magnetic tape during recording, that is, by changing the delay amount of the monostable multivibrator 12, a desired frame-by-frame playback speed can be obtained.

Note that the invention is not limited to the above embodiments. For example, the control signal may be recorded while the magnetic tape is stopped. Even in this manner, substantially the same tape pattern as in normal recording can be obtained. Also, the running distance of the magnetic tape is 1 track instead of 2 tracks.
It may be for a truck. Various other modifications can be made without departing from the spirit of the invention.

Furthermore, in this example, a rotational frequency detector that generates a frequency of 29.97 Hz during normal reproduction was used.
A rotational frequency detector that generates a frequency that is an integral multiple of this frequency may also be used. In this case, a branch is required, but
The recording pitch can be changed by changing the frequency division ratio of the divider IM device. In other words, if there are several playback speeds (for example, β■ in the beta format.

Two types of β■ are generally used).

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide an intermittent recording device that can accurately record at equal intervals even on a tape on which no control heads have been previously recorded.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a part of an embodiment of an intermittent recording device according to the present invention, FIG. 1 is a circuit diagram showing a specific configuration of a part of the circuit in FIG. 1, FIG. 5 is a circuit diagram of another part of one embodiment, and FIGS. 5 is a diagram illustrating the operation of the circuit shown in FIG. 5. 11 to 15... First to fifth monostable multi-novelators, 16... Capstan motor drive circuit, - tally transformer, 23... Video head, 24...1/
2 Counter, 25...Amplifier, 26...Control head, 2'1.2B...Switching transistor, 29...R-8 flip-flop, 30...D
Flip flop.

Claims (1)

[Claims] Recording video signals on magnetic tape
A rotational frequency detector that obtains a signal with a frequency proportional to the rotation of a capstan that drives the tape; a magnetic tape drive means that repeats the operation of abruptly stopping the magnetic tape using the signal as a curtain quasi-phase signal; and a video signal is recorded on the magnetic tape only during the period when the magnetic tape drive means is running the magnetic tape. An intermittent recording device characterized by comprising a video signal recording child actor.