JPS6048811B2 - magnetic recording and reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a magnetic recording system that records other control signals, such as cue signals, on the same CTL track based on reproduction pulses of a CTL track recorded in advance as a control (hereinafter referred to as CTL) signal on a videotape. The present invention relates to a recording/reproducing device.

In conventional video tapes, the CTL track is used to control a rotating head or capstan during playback, and only the positive pulses, for example, of the played pulses are used.

No other pulses are used. Therefore, adjacent CT
A method has been proposed in which a negative pulse is reproduced between the L reproduction pulses and used for purposes other than the above control, for example, as a cue signal.

To explain this with respect to a conventional video tape recorder (hereinafter referred to as VTR), in FIG.
A video signal 4 is recorded on the video track 2, and a CTL signal 7 as shown in FIG. 2B is recorded in saturation on the CTL track 3 by the CTL head 6 through the recording amplifier 5.

') CTL signal 7 is, as shown in Figure 2, a synchronization signal (
During playback, only the positive pulse corresponding to the rising edge is used for synchronous control of the rotary head or capstan, as shown in C in the figure. Here, the CTL rectangular wave signal B records on the video tape, for example, as a saturation magnetization pattern with the north pole at the positive part of the rectangular wave and the south pole at the negative part of the rectangular wave, as shown in FIG. . From the above explanation, since only the positive pulses of the reproduced signal C in FIG. 2C are used for control, the negative pulses can be used for other purposes.

For example, by changing the duty of the square wave signal B,
By moving the generation timing of the negative pulse of the reproduced signal C, it is possible to provide information as a cue signal, for example. This allows the CTL signal to be transmitted without any effect on the conventional CTL signal.
Tracks can also be used as cue tracks. However, when such a CTL track is also used, there are cases where it is desired to erase only the recorded cue signal and record a new cue signal, and in such a case, the CTL signal is affected.

The present invention rewrites the cue signal without affecting the recorded CTL.

The present invention will be explained below with reference to FIGS. 3 and 4.

In FIG. 3, 8 is a switcher serving as a first switching means, which allows the CTL head 6 and CTL amplifier 9 to
When connected, CTL. The signal reproduced from the rack is amplified by the CTL amplifier 9 to obtain a reproduced signal A as shown in FIG. 10, the CTL signal which becomes the first signal as shown in FIG. 4B. ' is amplified and output. In the negative polarity amplifier 14, only the negative polarity signal is amplified (not shown), and this is used as a cue signal, which is a second signal. The CTL signal B output from the positive polarity amplifier 10 is used for controlling the rotary head or capstan, and is also applied to the gate pulse generating means 12, which is a pulse generating means, and is converted into a CTL signal as shown in FIG. 4C. A gate pulse C is generated which occurs after a saw period and ends before the next CTL signal. This gate pulse C is applied to the switch 11 which is the second switching means.
When the switcher 11 becomes 0N due to the cue signal write command, which is a command to create a new second signal, the gate pulse operates the switcher 8, and the output of the cue signal recording circuit 13, that is, the new second signal. A third signal for creating two signals is applied to the CTL head 6 only during the gate pulse period. The cue signal recording circuit 13 generates a recording signal as shown in FIG. 4D, for example, based on the cue signal write command and the desired cue signal to be written at that time.

This example shows how to record in two sections of the control signal. In this case, the time interval between the CTL signal and the cue signal changes from the previous T, to T. This shows how to change the file and write it. At this time, first, due to the generation of gate pulse C,
CTL head 6 so that the saturation magnetization is the same polarity as the magnetization already saturated recorded on the video tape (in this case, north pole).
Apply a signal to. Depending on the queue signal to be written next.
The time T from the CTL signal. A signal in the opposite direction to the above is applied to the CTL head 6 with a delay of .times. As a result, the magnetization of the video tape is reversed (from a saturated north pole to a saturated south pole). This backward signal ends with the end of the gate pulse. Here, the end point of the gate pulse is set to be at the original S pole, so even if the reverse direction signal ends, the S pole remains on the tape. In this way, a new cue signal is recorded, and when played back, the fourth
A new cue signal is obtained as shown in Figure E. Next, another example is the time interval force between the CTL signal and the cue signal.
Cases in which this occurs are shown in FIGS. 4F and G. In this case as well, a new cue signal is recorded in the same manner as above, but in the above case the north pole of magnetization was reversed to the south pole midway through, but in FIG. 4F, the already recorded north pole has ended. Since the same direction signal is still applied to the CTL head 6 even when the tape becomes the S pole, the S pole on the tape during this time is reversed to the N pole by the CTL head 6. When the signal applied to the CTL head 6 is reversed by the cue signal, the magnetization is reversed to the south pole, and when the signal ends, the original south pole remains. When this is reproduced, a new cue signal is obtained delayed by the time Ta from the CTL signal, as shown in FIG. 4G.

In addition, in the above embodiment, the already recorded N of the videotape
We have described how to insert a new cue signal in either the pole or south pole, but when inserting a new signal only in the north pole (in this case, the number of rewrites is limited)
In FIG. 4D, it goes without saying that a positive direction pulse is not necessary and only a negative direction signal is sufficient.

Further, in the above embodiment, the gate pulse is always generated, but only when recording a cue signal, for example, in the above embodiment, the gate pulse is generated at CTL.
The cue signal may be introduced into the CTL head 6 by generating only two sections of the signal, thereby turning the switcher 8 on and off. Further, in this embodiment, the positive pulse is used as the CTL signal and the negative pulse as the cue signal, but the present invention can also be made as the negative pulse as the CTL signal and the positive pulse as the cue signal by simply reversing the polarity relationship in the above explanation. It is clear that it can be easily applied.

As explained in the above embodiments, according to the present invention, a new cue signal can be recorded on a CTL track without affecting the already recorded CTL signal.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a recording pattern of a videotape, Fig. 2 is a waveform diagram of its recording and reproduction signals, Fig. 3 is a block diagram showing an embodiment of the present invention, and Fig. 4 is its waveform diagram. . In the figure, 3 is a control track, 6 is a control head, and 13 is a cue signal recording circuit.

Claims (1)

[Scope of Claims] 1. A magnetic recording medium having one recording track in which saturation magnetizations having different polarities are recorded. A first signal is reproduced in accordance with a magnetization polarity reversal portion in one recording track, and a first signal is reproduced in accordance with a magnetization polarity reversal portion in one of the recording tracks, and a first signal is reproduced in the other recording track. In a magnetic recording and reproducing device that reproduces a second signal according to the magnetization polarity inversion section, the first signal is received and the second signal is reproduced after a predetermined period of time has elapsed since the first signal.
A pulse generating means generates an output during a period before inputting the next first signal following the signal, and the output of this pulse generating means and a third signal for creating a new second signal are inputted, and the pulse 1. A magnetic recording and reproducing apparatus comprising: recording means for recording saturation magnetization according to a third signal on the recording track during a period in which an output from the generating means is being generated. 2. Claim 1, characterized in that the magnetic recording medium is a videotape, the recording track is a control track, the first signal is a control signal, and the second signal is a cue signal. magnetic recording and reproducing device. 3. The recording means receives the output of the pulse generation means and receives a command to create a new second signal, and includes a second switching means for outputting the output of the pulse generation means, and a second switching means for generating a new second signal. a third signal to be generated and the output of the second switching means are input, and a first switching for outputting the third signal to the magnetic head during a period during which the output of the second switching means is input; 3. A magnetic recording and reproducing apparatus according to claim 1 or 2, characterized in that the magnetic recording and reproducing apparatus is configured to include means.