JP3575217B2 - Magnetic recording / reproducing device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a magnetic recording / reproducing apparatus capable of recording and reproducing both digital signals and analog signals, and more particularly to a reference signal required for displaying a state of the magnetic recording / reproducing apparatus on a screen.
[0002]
[Prior art]
Currently, analog video tape recorders (hereinafter, referred to as VTRs) using magnetic tapes have been put to practical use as home video and audio signal recording and reproducing devices.
[0003]
On the other hand, digital television broadcasting has been put into practical use as the next-generation television broadcasting, and while being compatible with current analog VTRs, digital compression-encoded video and audio signals such as digital television broadcasting are converted to digital signals. The development of a VTR capable of recording and reproduction is underway.
[0004]
Regarding such a VTR capable of recording and reproducing both digital signals and analog video and audio signals, for example, a configuration such as Nikkei Electronics (No. 634, pp. 16-17) has been considered.
[0005]
[Problems to be solved by the invention]
Many VTRs on the market today have built-in on-screen display circuits (hereinafter referred to as OSD circuits) for multiplexing information on analog video signals, and monitor the operation state of the VTRs on a monitor television ( (Hereinafter referred to as TV). At this time, in order to multiplex information into the analog video, it is necessary to supply a composite synchronizing signal serving as a reference for the analog video signal to the OSD circuit.
[0006]
On the other hand, the reference signal input to the servo circuit is a composite synchronizing signal which is an analog video synchronizing signal during analog recording / reproducing, and a digital signal synchronizing signal output from a digital signal processing circuit during digital recording / reproducing. At the time of recording / playback, the signal input to the servo circuit is different.
[0007]
In the conventional VTR, the reference signal supplied to the servo circuit and the reference signal supplied to the OSD circuit are configured to supply the same signal. Can not be done.
[0008]
[Means for Solving the Problems]
Before the information is multiplexed into the analog video, a signal having the same phase as the reference signal of the digital signal is generated in the servo circuit, and during the multiplexing of the information, the reference signal of the analog video signal is supplied to the OSD circuit. By switching the reference signal used in the servo circuit to the internally generated reference signal, it is possible to multiplex information into the analog video signal while keeping the rotation phase of the drum and the capstan locked.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
FIG. 1 is a circuit diagram showing one embodiment of a magnetic recording / reproducing apparatus according to the present invention. Here, 100 is a VTR, 200 is a digital satellite broadcast receiver (hereinafter referred to as IRD), and 300 is a TV.
[0011]
First, the components inside the VTR 100 will be described.
[0012]
Reference numeral 1 denotes a VTR-dedicated one-chip microcomputer, which controls the rotation of a drum and a capstan in addition to a central processing unit for performing arithmetic processing, a system control circuit 10 including a memory for storing an operation algorithm and internal information. A circuit necessary for controlling the VTR, such as a servo circuit 11 and an OSD circuit 12 for multiplexing information with an analog video signal, is incorporated. 2V is an analog video signal processing circuit for processing analog video signals, 2A is an analog audio signal processing circuit for processing analog audio signals, 2D is a digital signal signal processing circuit for processing digital signals, and 3 is analog broadcasting. , An input switch for switching an input source of analog video and audio signals, 5 a reference signal switch for switching a signal input to the one-chip microcomputer 1, and 110 an analog signal supplied from the IRD 200. An input terminal for inputting video and audio signals, a digital signal input / output terminal 111 for inputting / outputting a digital signal to / from the IRD 200, and an output terminal 112 for outputting analog video and audio signals to the TV 300. Further, although not shown, there are a mechanism such as a magnetic tape which is a medium for recording a signal, a magnetic head for writing a signal on the magnetic tape, a rotating drum having the magnetic head mounted thereon, and a capstan for running the magnetic tape.
[0013]
Here, the servo reference signal SREF output from the digital signal processing circuit 2D is a signal indicating the timing of digital data to be recorded on one track, and is used by the servo circuit 11 to determine the reference phase of the rotational phase of the drum and capstan during digital recording / reproduction. Used as The composite synchronizing signal Csync extracted from the analog video signal by the analog signal processing circuit 2V is a signal indicating the timing of the analog video signal to be recorded on one track, and the servo circuit 11 rotates the drum and capstan during analog recording. The signal is used as a reference phase of the phase, and is also used by the OSD circuit 12 as a timing signal for multiplexing information on analog video. Which of the servo reference signal SREF and the composite synchronization signal Csync is to be input to the one-chip microcomputer 1 is determined by the system control circuit 11 controlling the reference signal switch 5 according to the operation mode of the VTR.
[0014]
Next, components inside the IRD 200 and the TV 300 will be described.
[0015]
201 is a digital broadcast receiving tuner that receives digital broadcasts, 202 is a decoder that converts digital signals into analog video and audio signals, 203 is a changeover switch that selects a signal to be supplied to the decoder, and 210 is an analog video and audio signal output An output terminal 211 is a digital signal input / output terminal for inputting / outputting digital signals to / from the VTR 100, and 310 is an input terminal for inputting analog video and audio signals. The VTR 100 and the IRD 200 are connected to each other by a communication line that can control the state of each other. For example, the system control circuit 10 of the VTR 100 can switch the contact of the changeover switch 203 of the IRD 200. .
[0016]
The outline of the operation at the time of analog recording / reproduction and digital recording / reproduction of this magnetic recording / reproducing apparatus is as follows.
[0017]
First, a case where a digital broadcast signal is recorded will be described.
[0018]
When recording a digital broadcast signal, the system control circuit 10 sets the digital signal processing circuit 2D, the analog video signal processing circuit 2V, and the analog audio processing circuit 2A to the recording mode, sets the servo circuit 11 to the digital recording mode, and switches the reference signal. The switch 5 is connected to the contact D, the input switch 4 is connected to the contact D, and the switch 203 of the IRD 200 is connected to the contact R.
[0019]
The digital broadcast signal input to the digital broadcast signal input terminal 212 is demodulated into a digital signal by the digital broadcast receiving tuner 201, and the digital signal is supplied to the digital signal output terminal 211 o and the contact R side of the changeover switch 203. The digital signal output from the digital signal output terminal 211o is input to the digital signal processing circuit 2D via the digital signal input terminal 111I, where transmission path coding processing such as addition of an error correction code and modulation is performed. Are supplied to the magnetic head. Further, the digital signal processing circuit 2D supplies a servo reference signal SREF, which is a timing signal for recording a digital signal, to the servo circuit 11, and the servo circuit 11 sets the rotation phase of the rotating drum and the capstan to the phase of the reference signal SREF. Control is performed so as to match, and a digital signal is recorded while drawing a fixed recording track on the magnetic tape.
[0020]
The output of the digital broadcast receiving tuner 201 is input to the decoder 202 via the changeover switch 203, and is converted into analog video and audio signals. The analog video signal is supplied to the input terminal 310V of the TV 300 via the output terminal 210V, the input terminal 110V, the input switch 4V, the analog video signal processing circuit 2V, the OSD circuit 12, and the output terminal 112V, and the analog audio signal is output. The digital broadcast program being supplied to the input terminal 310A of the TV 300 via the terminal 210A, the input terminal 110A, the input switch 4A, the analog video signal processing circuit 2A, and the output terminal 112A can be viewed.
[0021]
Next, a case where an analog broadcast signal is recorded will be described.
[0022]
When recording an analog broadcast signal, the system control circuit 10 sets the analog video signal processing circuit 2V and the analog audio signal processing circuit 2A to the recording mode, sets the servo circuit 11 to the analog recording mode, and sets the input switch 4 to the contact A side. Then, the reference signal switch 5 is connected to the contact A side.
[0023]
The analog video and audio signals supplied from the analog broadcast receiving tuner 3 are subjected to recording signal processing in an analog video signal processing circuit 2V and an analog audio signal processing circuit 2A, and are supplied to a magnetic head. The analog video signal processing circuit 2V supplies a composite synchronizing signal Csync, which is a timing signal for recording the analog video signal, to the servo circuit 11, and the servo circuit 11 converts the rotational phase of the rotating drum and the capstan into a composite synchronizing signal Csync. And the analog video and audio signals are recorded while drawing a fixed recording track on the magnetic tape.
[0024]
The analog video signal is supplied to the input terminal 310V of the TV 300 via the OSD circuit 12 and the output terminal 112V, and the analog audio signal is supplied to the input terminal 31A of the TV 300 via the output terminal 112A. You can watch broadcast programs.
[0025]
Note that when recording a digital broadcast signal in an analog manner, it is exactly the same as that for recording an analog broadcast signal, except that the contact of the input switch 4 is connected to the D side.
[0026]
Next, the operation of reproducing a digital signal will be described.
[0027]
When reproducing a digital signal, the system control circuit 10 sets the digital signal processing circuit 2D to the reproduction mode, sets the analog video signal processing circuit 2V and the analog audio signal processing circuit 2A to the recording mode, and sets the servo circuit 11 to the digital reproduction mode. The reference signal switch 5 is connected to the contact D, the input switch 4 is connected to the contact D, and the switch 203 of the IRD 200 is connected to the contact P.
[0028]
The digital signal processing circuit 2D supplies the servo reference signal SREF to the servo circuit 11, and the servo circuit 11 performs control so that the rotation phases of the rotating drum and the capstan match the servo reference signal SREF, and the magnetic head is recorded. Plays digital signals. This signal is processed by the digital signal processing circuit 2D in a manner opposite to that at the time of recording, and is supplied to the decoder 202 via the digital signal output terminal 111o, the digital signal input terminal 211I, and the switch 203, and is converted into an analog video and audio signal. Is done. The analog video signal is supplied to the input terminal 310V of the TV 300 via the output terminal 210V, the input terminal 110V, the input switch 4V, the analog video signal processing circuit 2D, the OSD circuit 12, and the output terminal 112V, and the analog audio signal is output. The video and the audio, which are supplied to the input terminal 310A of the TV 300 via the terminal 210A, the input terminal 110A, the input switch 4A, the analog video signal processing circuit 2A, and the output terminal 112A, and decode the digital signal being reproduced, can be viewed.
[0029]
Finally, the operation of reproducing the analog signal will be described.
[0030]
When reproducing an analog signal, the system control circuit 10 sets the analog video signal processing circuit 2V and the analog audio signal processing circuit 2A to the reproduction mode, and sets the servo circuit 11 to the analog reproduction mode.
[0031]
The servo circuit 11 performs control so that the rotation phases of the rotating drum and the capstan match the internally generated phase reference signal, and reproduces analog video and audio signals recorded by the magnetic head. These signals are respectively processed by the analog video signal processing circuit 2V and the analog audio signal processing circuit 2A in a reverse manner to those at the time of recording. The analog video signal is input to the input terminal 310V , And the analog audio signal is supplied to the input terminal 310A of the TV 300 via the output terminal 112A, so that the analog video and audio signals being reproduced can be viewed.
[0032]
The rough operation at the time of recording and reproduction has been described so far. Next, detailed operations of the reference signal switch 5, the servo circuit 11, and the OSD circuit 12 will be described with reference to FIGS. 2, 3, 4, and 5. It will be described using FIG.
[0033]
FIG. 2 shows the one-chip microcomputer 1, the tape type detection circuit 4, and the reference signal changeover switch 5 extracted from FIG. 1, and also shows the internal configuration of the servo circuit 11. Reference numeral 20 denotes a phase reference signal generation circuit that generates a phase reference signal serving as a reference of the rotation phase of the drum and the capstan. 26 denotes a drum rotation control circuit that controls the rotation of the rotary drum. 27 denotes a capstan rotation that controls the rotation of the capstan. It is a control circuit. FIG. 2 also shows the internal configuration of the phase reference signal generation circuit 20. Reference numeral 21 denotes a vertical synchronization signal generation circuit that extracts the vertical synchronization signal Vsync from the decoded synchronization signal Csync and generates the reference signal REFOUT. A rectangular wave output circuit that outputs a rectangular wave REFIN having a fixed period by using a clock such as a clock, a switch 23 for selecting the signal REFOUT and the signal REFIN, and a forcible output timing of the rectangular wave output circuit 22. A reset changeover switch 25 for resetting is a frequency divider that divides the signal output from the changeover switch 23 by two. The control of the changeover switches 23 and 24 and the cycle setting for the rectangular wave output circuit are performed by the system control circuit 10.
[0034]
FIG. 3 is a diagram for explaining the operation of the vertical synchronization signal generation circuit 21.
[0035]
The vertical synchronizing signal generation circuit 21 counts up during a period when an input signal is “H”, counts down during a period when the input signal is “L”, and when a value of the counter exceeds a specified value. And an output circuit for outputting a signal of "L" when the value is equal to or less than a specified value. In FIG. 3, reference numeral 30a denotes a composite synchronizing signal Csync output from the analog video signal processing circuit 2V, and 31a denotes a synchronizing signal SREF output from the digital signal processing circuit 2D. The waveforms of the counter and output signal when these two signals are input to the vertical synchronization signal generation circuit 21 are shown in 31a, 31b and 30c, 31c.
[0036]
The signal 30a, that is, the first part of the composite synchronization signal Hsync is a part corresponding to the vertical synchronization signal Vsync, and the latter pulse is a part corresponding to the horizontal synchronization signal Hsync. The screen of each video signal is synchronized with the vertical synchronization signal Vsync, and the vertical synchronization signal Vsync is used as a reference for the rotation phase of the drum and the capstan during analog recording. In the vicinity of the vertical synchronization signal Vsync, since the period during which the signal is at “H” is longer than the other portions, the output waveform 30c has a waveform almost in phase with the vertical synchronization signal Vsync.
[0037]
The signal 31a, that is, the "H" portion of the synchronization signal SREF indicates the output timing of the digital data for each track output by the digital signal processing circuit 2D. At the time of digital recording / reproduction, the synchronization signal SREF is output to the drum and the capstan. Is used as a reference for the rotational phase of. Since the time during which the synchronizing signal SREF is at “H” is sufficiently long, the output waveform 31C has a waveform almost in phase with the synchronizing signal SREF.
[0038]
FIG. 4 is a diagram for explaining the operation of the rectangular wave output circuit 33.
[0039]
The rectangular wave output circuit 33 includes a counter for resetting at a predetermined cycle and an output circuit for outputting "H" when the value of the counter is zero and outputting "L" when the value of the counter is a predetermined value. . Also, the counter can be reset from outside. The reset period of the counter and the value of the “L” output of the output circuit can be changed by the system control circuit 10.
[0040]
The rectangular wave output circuit 33 continues to output a rectangular wave having a fixed cycle set by the system control circuit 10 when no reset is applied from the outside, but forcibly resets the counter value when a reset pulse is input from the outside. Therefore, a signal synchronized with the external reset pulse is output.
[0041]
The operation when such a configuration is used will be described focusing on the signal output from the phase reference signal generation circuit 20.
[0042]
First, operations during analog recording and analog reproduction will be described. In these states, the reset switch 24 is connected to the contact N side.
[0043]
At the time of analog recording, it is necessary to match the rotation phase of the drum in accordance with the video timing of each field of the video signal to be recorded. Therefore, the reference signal switch 5 is connected to the contact A, and the switch 23 is connected to the contact R. Then, a signal obtained by dividing the frequency of the vertical synchronization signal Vsync by 2 is generated as a phase reference signal. Also, at the time of analog reproduction, it is necessary to match the rotation phase of the drum with a signal having the same cycle as the reference signal used at the time of recording, so the changeover switch 23 is connected to the contact P side, and the vertical synchronizing signal is The same cycle as Vsync, ie, “1 / 59.94” seconds, is set, and a signal having the same frequency as the reference signal at the time of recording is generated as a phase reference signal.
[0044]
At the time of analog recording and reproduction, since the reference signal changeover switch 5 is connected to the A side, the composite synchronizing signal Csync is also input to the OSD circuit, and information can be multiplexed on the analog video signal.
[0045]
Next, operations during digital recording and digital reproduction will be described.
[0046]
At the time of digital recording and reproduction, it is necessary to match the rotation phase of the drum with the reference signal SREF output by the digital signal processing circuit 2D. Therefore, the reference signal switch 5 is connected to the contact D, and the switch 23 is connected to the contact R. Then, a signal obtained by dividing the reference signal SREF by 2 is generated as a phase reference signal. Further, the reset changeover switch 22 is connected to the contact R side, and the phase of the signal REFIN output from the rectangular wave output circuit 22 matches the phase of the servo reference signal SREF. Further, the reset cycle of the rectangular wave output circuit 22 is set to the same cycle as the reference signal SREF output from the digital signal processing circuit 2D, that is, "1/60" seconds.
[0047]
When multiplexing information into an analog video signal during digital recording and reproduction, the system control circuit 10 sends necessary information to the OSD circuit 12 to control display and sets the reference signal switch 5 to the contact A side. Then, the changeover switch 23 is switched to the contact P side, and the reset changeover switch 24 is switched to the contact N side.
[0048]
Since the reference signal changeover switch 5 is switched to the contact A side, the composite synchronizing signal Csync is supplied to the OSD circuit 12, and the information can be multiplexed on the analog video signal. Also, since the changeover switch 23 is switched to the contact P side and the reset changeover switch 24 is switched to the contact N, the phase reference signal generation circuit 30 outputs a rectangular wave having the same cycle as the cycle set in the rectangular wave output circuit 22, A signal having the same cycle as the signal SREF is output. Furthermore, since the rectangular wave output circuit 22 is reset by the reference signal SREF when information is not multiplexed, the signal output from the phase reference signal generation circuit 30 is a signal whose phase matches the reference signal SREF. Therefore, the rotation phase of the drum and the capstan is continuously controlled to the same phase as before the information is multiplexed.
[0049]
When the multiplexing of the information is completed, the system control circuit 10 returns the contacts of the reference signal changeover switch 5, the changeover switch 23, and the reset changeover switch 24 to the state before the multiplexing of the information. Also at this time, the phase of the signal REFIN generated by the rectangular wave output circuit 22 during the multiplexing of information and the phase of the reference signal SREF match, so that the rotational phase of the drum and the capstan is Is kept in the same phase as.
[0050]
FIG. 5 is a table summarizing the above states. With respect to the state of the VTR shown on the left end, the connection destinations of the changeover switches 5, 23, and 24 and the signals output from the phase reference signal generation circuit 30 are shown.
[0051]
As described above, even when information is multiplexed into an analog video signal during digital recording / reproduction, a signal having the same phase as the servo reference signal SREF is used as a phase reference signal. The rotation phase is constant.
[0052]
It is conceivable to make the servo circuit 11 perform the same control as during digital recording / reproduction during standby, but at this time, the operation of the one-chip microcomputer 1 and the reference signal changeover switch 5 when multiplexing information into an analog video signal is performed. Is exactly the same as the operation during digital recording / playback.
[0053]
If the accuracy of the cycle of the output waveform of the square wave output circuit 22 is not sufficient, the phase of the signal REFIN output by the square wave output circuit 22 becomes different from the servo reference signal SREF during the multiplexing of information at the time of digital recording / reproduction. It is conceivable that it will gradually shift. Since the phase of the phase reference signal REF is not allowed to fluctuate during digital recording / reproducing, when the accuracy of the rectangular wave output circuit 22 is not sufficient, the reference signal changeover switch 5 is fixed to the contact D side during digital recording / reproducing. Multiplexing is not performed, and control of the changeover switch is performed only during standby as shown in FIG.
[0054]
Further, at the time of reproduction, it is determined whether the recorded signal is a digital signal or an analog signal, and the magnetic recording device 100 is switched to digital reproduction or analog reproduction operation. When the setting of the servo circuit 11 is set to the mode for digital reproduction during the above determination, the contact of the reference signal switch 5 is fixed to the D side at the start of reproduction, and information is not multiplexed.
[0055]
FIG. 6 is a block diagram showing a second embodiment of the magnetic recording / reproducing apparatus according to the present invention.
[0056]
In this example, the VTR 100 and the IRD 200 shown in FIG. 1 or FIG. In this case, an input / output terminal for each signal that moves between the VTR 100 and the IRD 200 is unnecessary.
[0057]
FIG. 7 is a block diagram showing a third embodiment of the magnetic recording / reproducing apparatus according to the present invention.
[0058]
This example shows an example in which reference signal input terminals to the servo circuit 11 and the OSD circuit 12 are provided independently. In such a configuration, the composite synchronizing signal Csync is always supplied from the analog video signal processing circuit 2V to the OSD circuit 12. Therefore, even when information is multiplexed into the video signal during digital recording / reproduction, the reference signal switch is used. 5. There is no need to switch the connection destination of the changeover switch 23 and the reset changeover switch 24.
[0059]
FIG. 8 is a block diagram showing a fourth embodiment of the magnetic recording / reproducing apparatus according to the present invention.
[0060]
In this example, an output changeover switch 6 for switching the analog video and audio signals output from the VTR 100 is added to FIG. 7, and the input changeover switch 4 is connected to the contact A, and the contact of the output changeover switch 6 is connected to the D side. By doing so, it is possible to view a digital broadcast program supplied from the IRD 200 while recording an analog broadcast program.
[0061]
When multiplexing information into an analog video in such a configuration, it is necessary to multiplex the information not into the recorded analog video but into the analog video signal output from the VTR 100. Therefore, the OSD circuit 12 for multiplexing the information is required. And a composite synchronizing signal extraction circuit 7 for supplying a composite synchronizing signal Csync to the OSD circuit 12 after the output changeover switch 6V.
[0062]
The embodiments of the present invention have been described above.
[0063]
In FIGS. 1, 6, 7, and 8, examples in which the system control circuit, the servo circuit, and the OSD circuit are incorporated in one chip have been described. However, this is not particularly limited. May exist independently. In the above description, the period set in the rectangular wave output circuit at the time of digital recording / reproduction is a fixed period. For example, the period of the reference signal SREF is actually measured by the system control circuit, and the period is set. May be.
[0064]
【The invention's effect】
According to the present invention, the reference signal of the analog video signal is always supplied to the OSD circuit during the multiplexing of the information on the analog video signal, and the phase of the reference signal SREF of the digital signal always coincides with the digital signal during the recording / reproducing. Since the obtained signal is used as a phase reference signal, it is possible to multiplex information into an analog video signal even during digital recording / reproduction.
[Brief description of the drawings]
FIG. 1 is a block diagram showing one embodiment of a magnetic recording / reproducing apparatus according to the present invention.
FIG. 2 is a block diagram showing an internal configuration of a servo circuit used in the present invention.
FIG. 3 is a diagram for explaining the operation of a reference signal generation circuit used in the present invention.
FIG. 4 is a diagram for explaining the operation of the rectangular wave output circuit used in the present invention.
FIG. 5 is a diagram showing a phase reference signal output from a phase reference signal generation circuit in a VTR mode.
FIG. 6 is a block diagram showing another configuration example according to the present invention.
FIG. 7 is a block diagram showing another configuration example according to the present invention.
FIG. 8 is a block diagram showing another configuration example according to the present invention.
[Explanation of symbols]
1. One-chip microcomputer,
2V: analog video signal processing circuit,
2A: an analog audio signal processing circuit,
2V: Digital signal processing circuit,
3 ... Analog broadcast receiving tuner,
4 ... input changeover switch
5 ... Reference signal switch
6 ... output changeover switch
7 ... combined synchronous signal extraction circuit
10 ... System control circuit,
11 ... servo circuit,
12 ... OSD circuit,
13 ... timer
20 ... phase reference signal generation circuit,
21 ... vertical synchronizing signal generation circuit,
22 ... rectangular wave output circuit,
23 ... changeover switch,
24 reset switch,
25 ... frequency divider,
26 ... drum rotation control circuit,
27 ... Capstan rotation control circuit,
100 ... VTR,
200 ... IRD,
300 ... TV.

Claims (8)

A rotating drum equipped with a magnetic head,
A tape running mechanism for running a magnetic tape wound around the rotating drum,
In a magnetic recording and reproducing apparatus for selecting a digital information signal and an analog video signal and recording on the magnetic tape with the magnetic head, and reproducing the recorded signal,
Control means for controlling the rotation phase of the rotating drum and the running phase of the magnetic tape,
First reference signal generating means for generating a first reference signal synchronized with the digital information signal being recorded or reproduced,
A second reference signal generation unit that generates a second reference signal synchronized with the input or reproduced analog video signal,
Information multiplexing means for multiplexing and outputting information to an input or reproduced analog video signal ,
Before SL control means said first reference signal is recorded during reproduction of the digital information signal, said at recording and reproduction of analog video signal using the second reference signal as a reference signal for phase control,
A magnetic recording / reproducing apparatus, wherein the information multiplexing means uses the second reference signal as a reference signal for multiplexing information when recording / reproducing the digital information signal and recording / reproducing the analog video signal . 2. The magnetic recording / reproducing apparatus according to claim 1, wherein when the information multiplexing unit does not multiplex information, the control unit is supplied with the same reference signal as the reference signal used by the information multiplexing unit. . The control means generates a third reference signal synchronized with the first reference signal, and uses the third reference signal as a reference signal for phase control when multiplexing information. The magnetic recording and reproducing apparatus according to claim 1. 2. The magnetic recording / reproducing apparatus according to claim 1, wherein the information multiplexing unit does not multiplex information when recording / reproducing a digital information signal. 2. The magnetic recording apparatus according to claim 1, wherein the information multiplexing unit does not multiplex information when starting reproduction when a recording medium capable of recording a digital information signal is inserted into the recording / reproducing apparatus. Playback device. When recording and reproducing the digital information signal, an analog video signal obtained by converting the digital information signal being recorded or reproduced into an analog video signal is supplied to the second reference signal generating means and the information multiplexing means. The magnetic recording / reproducing apparatus according to claim 1. An analog video signal that is recorded or reproduced, the switching means is an analog video signal to enter another analog movies No. Zoshin selects and outputs that the recording or reproducing,
Comprises a fourth reference signal generating means for generating a fourth reference signal synchronized with the analog video signal the switching means outputs,
2. The magnetic device according to claim 1, wherein the analog video signal output from the switching unit is input to the information multiplexing unit, and the information multiplexing unit uses the fourth reference signal as a reference signal for multiplexing information. Recording and playback device. 8. The magnetic recording / reproducing apparatus according to claim 7, wherein the analog video signal different from the analog video signal being recorded or reproduced is a signal obtained by demodulating a digital broadcast signal and converting it into an analog video signal. .

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