JPS59100676A - Multiplex recording system and multiplex recording and reproducing system - Google Patents

Abstract

PURPOSE:To prevent the generation of moire by forming one track pitch for an FM sound signal with an exclusive rotary head and recording a video track superimposed on the recorded track. CONSTITUTION:Video signal recording and reproducing rotary heads H1, H2 are fitted on a rotary drum 1 respectively in the interval of 180 deg.. Sound signal recording and reproducing rotary heads HA1, HA2 are fitted to a position in preceding by an angle theta to the rotary heads H1, H2. The video track recorded by the rotary heads H1, H2 and the sound track formed by the rotary heads HA1, HA2 are recorded on the same position. Thus, the mutual interference due to beat between carrier frequencies is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a multiplex recording system and a multiplex recording/reproducing system, and more particularly to a system for recording an audio signal on the same track as a video signal and reproducing the same.

Conventional technology Helical scanning magnetic recording/reproducing device (VTR)
In this method, a plurality of, for example, two, rotating heads are attached to a rotating body such as a rotating drum at equal angular intervals, and a magnetic tape is attached to the rotating body and is caused to run while being wound over an angular range of, for example, more than 180°. , the video signal is recorded on the magnetic tape by a rotating head, the audio signal is recorded by a fixed head installed in the middle of the magnetic tape running path, and during playback, the video signal is played back by the rotating head and the fixed head is It is well known that audio signals are reproduced by a head.

On the other hand, the recording and reproducing time of VTRs has tended to become longer in recent years, and the running speed of magnetic tapes has accordingly tended to decrease. Furthermore, it is desired that the audio signal be reproduced with high quality. However, audio signals are recorded on magnetic tape using a fixed head.

Since the relative linear velocity between the i-p and the head is low during playback, if the running speed of the magnetic tape is slowed down, the frequency characteristics of the audio signal will be much more significant than the frequency characteristics of the video signal recorded and played back by the rotating head. The quality deteriorated, making it impossible to record and play back high-quality audio signals.

Therefore, conventionally, a method has been proposed in which an audio signal is converted into a predetermined signal format and superimposed on a video signal, and this superimposed signal is recorded on a magnetic tape by a video signal No. 9- recording and reproducing rotary head, and then reproduced. ing. According to this recording/playback method, audio signals are recorded and played back by a rotating head on a magnetic tape with a high relative linear velocity between the tape and the head. Compared to the case where audio signals are recorded and reproduced using a head without slowing down the running speed of the magnetic tape, it is possible to record and reproduce audio signals with much higher quality.

Problems to be Solved by the Invention However, in the recording and reproducing method proposed above, an audio signal is subjected to at least frequency modulation and then superimposed on a video signal consisting of, for example, a frequency modulated luminance signal and a low frequency converted carrier color signal. Since this superimposed signal is recorded and reproduced by the same rotary head, there is a problem in that beats occur between carrier frequencies and the beats cause interference (moiré) on the reproduced screen.

Therefore, an object of the present invention is to provide a multiplex recording system and a multiplex recording/reproduction system that solve the above problem 10- by recording and reproducing audio signals using a dedicated rotary head.

Means for Solving the Problems The present invention provides a rotating body in which a magnetic recording medium is spliced and wound over a certain angle range, and a plurality of video signal recording/reproducing rotary heads and video recording media having different azimuth angles. Two audio signal recording/reproducing rotary heads with different azimuth angles than the signal recording/reproducing rotary head are each installed, and N times more than the signal recording/reproducing rotary head (N is the number of fields of the video signal recorded on one track). ) is a frequency-division multiplexed signal of frequency-modulated audio signals of multiple channels whose respective modulation signals are time-compressed audio signals having different carrier frequencies, or a frequency-division multiplexed signal of frequency-modulated audio signals of multiple channels having mutually different carrier frequencies, or The first .channel where the audio signals of the channels are the respective modulation signals. Second
A time-division multiplexed signal of a frequency modulated audio signal is supplied to the audio signal recording/reproducing rotary head every track scanning period, and the audio signal recording/reproducing rotary head transfers the frequency to the traveling magnetic recording medium. The audio tracks 1 to 1 on which modulated audio signals are recorded are formed in one track pitch, and the video tracks in which video signals are recorded on the magnetic recording medium by the video signal recording/reproducing rotary head are formed in one track pitch. The video 1~rack is recorded over the recorded audio 1~rack, and during playback, the frequency modulated audio signal taken out from the rotary head for audio signal recording and playback is demodulated for each channel. At the same time, the reproduced audio signals of each channel of the original audio pitch are continuously extracted by time expansion.Each embodiment will be described below with reference to the drawings.

Embodiment FIGS. 1 and 2 each show an embodiment of the present invention (head arrangement relationship, etc.). In both figures, the same components are given the same reference numerals. On the rotating surface of a rotating drum 1, which is an example of a rotating body, rotating heads 11 and 1''2 for recording and reproducing video signals are mounted facing each other at an interval of 180 degrees, and rotating heads H1 and H2.
Rotary heads IAI and HA2 for recording and reproducing audio signals are fixedly mounted at a position preceding the rotary head by an angle θ in the rotation direction. The rotary heads 1''1 and []2 are mounted at the same height as shown in FIG. 2, and are mounted at a height d higher than the rotary heads HAI and 1-IA2. The lower surface of the rotating drum 1 is the fixed drum 2.
The guide poles 4a, 4a, 4a, 4a, 4a, 4a, 4a, 4a, 4a, 4a, 4a, 4a, 4b, 4b, 4b, 4a, 4a, 4a, 4a, 4a, 4b, and, the magnetic tape 3 is provided at a position opposite to the upper surface by a small distance.
4b over an angular range of just over 180°,
Moreover, it is wound around the rotating drum 1 in an inclined manner. During recording and reproduction, the rotary drum 1 is rotated counterclockwise in FIG. 1, and the magnetic tape 3 is run in the X direction.

Further, the rotating heads I+ and H2 have different azimuth angles from each other, and the rotating heads HAI.

HA2 is selected to have an azimuth angle that is sufficiently larger than the azimuth angles of the rotating heads 11 and H2.

As will be described later, video tracks recorded and formed by the rotary heads H2 and H+ and the rotary head HAI.

Since the audio track recorded and formed by 13-1@A2 is recorded and formed at the same position, both rotating heads 1-12 and H
It is advantageous that the azimuth angle difference between A+, Hl and 1''A2 is larger than that between rotating head 11 and t-L+, or between 1''2 and 1-IA2. In addition, in order to reproduce the audio signal with less mutual interference with the video signal,
The azimuth angles of the rotating heads HAI and HA2 need to be the same as the azimuth angles of the rotating heads H1 and H2, and in order to minimize the mutual interference mentioned above for reproduction, the azimuth angles of the rotating heads H+ and 1-12 should be made equal to each other. It is desirable to select a sufficiently large size. In view of the above points, - As an example, the azimuth angle of the rotating head H1 is -6°, +-12°.
That of 1''A1 is +6°, and that of 1''A1 is -30°.

That of hl A 2 is selected to be +306.

Furthermore, in order to record and form the video i-rack recorded and formed by the rotary heads H2 and HI and the audio track recorded and formed by the rotary heads HA+ and HAz at the same position, the rotary heads HAI and HA2 are rotated as described above. It is provided at a position that precedes the heads H+ and H2 in the rotational direction by an angle of 14 degrees θ and is lower by a height d. - By way of example, the diameter of the rotating drum 1 is 62 mm, θ is chosen to be 55° and d to be 1811 m. Note that since the height position differs by the above distance d, the rotating head HA+.

The starting end of the audio track recorded from HA2t is
Rotating head 1-12. The starting edge J of the video track recorded by H+ is shifted by about 18 μm, but this shift is extremely small and can be virtually ignored.

Next, to explain the signal processing system of the present invention, FIG. 3 shows a block diagram of an embodiment of the recording system of the present invention. In the figure, the same components in FIGS. 1 and 2 are designated by the same reference numerals. In FIG. 3, input terminals 5 and 6 receive, for example, a left channel audio signal and a right channel 17 audio signal separately, and input terminal 7 receives a standard color video signal. The left channel audio signal entering the input terminal 5 is first supplied to a low-pass filter 9 in a left channel audio signal recording system 8. The low-pass filter 9 removes frequency components of, for example, 15kl-1z or higher from the input audio signal. The second packet brigade device (r
10.11 (referred to as BBDJ) respectively. The low pass filter 9 is BBDlo.

11 is provided to remove signal components outside the operating band.

On the other hand, a rotation detection pulse, that is, a so-called drum pulse, which has a period equal to one rotation period of the rotary drum 1 and is synchronized with the rotation phase of the rotary drum 1, generated by a known means, is supplied from an input terminal 12 to a clock pulse generator 13. be done. Note that a horizontal synchronization signal or a color burst signal may be supplied to the clock pulse generator 13 instead of the drum pulse.

Figure 4<A) shows the signal waveform of this drum pulse, and 1
If one field of video signal is to be recorded to a book track, it is a symmetrical rectangular wave with a period of two fields. The clock pulse generator 13 generates writing clock pulses W, CK of a predetermined repetition frequency f based on this drum pulse (or horizontal synchronization signal, colorverse 1~ signal),
Read clock pulse R with repetition frequency 1.21
, CK are generated, respectively. The clock pulse for writing is always generated and output as shown schematically in FIG. 4(B), while the clock pulse for reading is generated as shown schematically in FIG. 4(C). , is output.

The write clock pulses W and CK are applied to the contact ■ of the switch SWa and the contact ■ of the switch SWb, respectively, and the read clock pulses R and GK are applied to the contact ■ of the switch SWa and the contact ■ of SWh, respectively. In addition, the contacts ■ and ■ of the switch SWC are the output terminal of the first BBDlo, and the contacts
It is connected to the output end of BBDll of switch SWc, and the contact point (2) of switch SWc is an empty contact point. These switches SWa to SWC are actually constituted by electronic switch circuits, and their switching is controlled by switching pulses taken out from a switching pulse generator (not shown). FIG. 4(D) shows the switching timing of the switch SWa, which is alternately connected to the contacts ① and ②.

17- Also, Fig. 4 (E) shows the switching timing of the switch SWb, and out of the period of just over one field in which the switch SWa is connected to the contact ■, the period of a little less than one field is connected to the contact ■. , switch SWa is connected to contact ■1
The contact point (2) is switched to be connected for a period of just over one field, and a period of a little more than one field, from the period immediately preceding it indicated by T1 to the period indicated immediately after it indicated by T2. Furthermore, Figure 4 (
F) indicates the switching timing of switch SWc, and
■→■→■→■→■→... are switched sequentially. During the period of a little over one field when the switch SWa is connected to the contact point ■, the writing clock pulse W is applied to BBDlo.
, CK are applied and the read clock pulses R and CK are applied to BBDlo during a period of a little less than one field when SWa is connected to the contact point (3). Also, switch SWb is BBD
Write clock pulses W and GK are applied for a period of a little over one field connected to the contact ■ for ll, and the contact ■ is connected to the contact ■.
The read clock pulses R and GK are applied for a period of a little less than one field connected to. As a result of this, BBDlo and 11 are controlled so that when one is performing a read operation, the other one is performing an old read operation.

First, the audio signal for one field period in which the drum pulse is at a high level is input to BBDlo by a clock pulse with a repetition frequency f, and then to the next T1 in Fig. 4 (B).
Since the switch SWa continues to be connected to the contact ■, the audio signal for a certain period indicated by is also written to BBDIO. On the other hand, since the switch SWb is connected to the contact ■ from the time when the drum pulse becomes low level, the switch SWb is connected to the contact point ■ for the period T
The audio signal of 1 is simultaneously written to BBDl 1 by clock pulses with a repetition frequency of 1.

When the above period T1 has elapsed, the switch SWa is connected to the contact ■ as shown in FIG. 4(r), so that the BBDI
Just over 1 field (1 field - 1 - T+) written in O with a clock pulse of repetition frequency f
The audio signal for the period 2 is read out using a clock pulse having a repetition frequency of 1.2 f, and is then supplied to the low-pass filter 14 through the switch SWC connected to the contact 2, as shown in FIG. 4(F). As schematically shown in FIG. 4(C), the period during which a little over one field of audio signals is read out from BBDIO is approximately 2T1 shorter than the one field period, and at the time when the reading ends, switch SWc is
is connected to contact ■. No audio signal is applied to the low-pass filter 14 during a short period when the switch SWC is connected to the contact point (3).

When the drum pulse changes from the low level to the high level, the switch SWa is connected to the contact ■ and causes the BBDIO to start the write operation again, and when the period T2 elapses, the fourth
As shown in Figure (E), at the same time as the switch SWb switches from the contact point ■ to the contact point ■, the switch SWc changes from the contact point ■ to the contact point ■. When this period T2 has elapsed, the BBDll has a period T
The audio signal for a period of just over one field including 1 has been written by the clock pulse of frequency f, and from that point on, the clock pulse of frequency 1.2f is used to write the audio signal of the king from BBDl 1. The signal is read out once for a period of a little less than one field, and at this time is supplied to the low-pass filter 14 through the switch SWc connected to the contact point (3).

In this way, the time is compressed by 1.2 times, and the fourth
The left channel audio signal with overlapped short-term audio information shown as T+ and T2 in the figure is intermittently taken out from the switch SWC at the timing schematically shown in FIG. 4(C).
After unnecessary frequency components are removed by a low-pass filter 14, the signal is supplied to a frequency modulator 15, where it is frequency-modulated. The signal is supplied to the first FM sound/speech signal mixing circuit 16 having a carrier frequency f+ (for example, 1.35 M l-I Z ) intermittently taken out from the frequency modulator 15 . Note that the maximum frequency deviation of the first FM audio signal is, for example, ±
It is 100kl-12.

On the other hand, the right channel audio signal input to input terminal 6 is
The signal is supplied to a right channel audio signal recording system 17 having the same configuration as the left channel audio signal recording system 8 described above, where 1.
The maximum frequency deviation when the carrier frequency fz (for example, 1.621-Mn2) is frequency-modulated with the right channel audio signal that has been time-compressed twice is, for example, ±1.
The signal is converted into a second FM audio signal of 00kl-12, which is intermittently extracted and supplied to the mixing circuit 16.

As a result, the first and second frequency division multiplexed signals are intermittently taken out from the mixing circuit 16 and supplied to the two audio signal recording/reproducing rotary heads 1-IAI and HA2 via the single rotary transformer 18. be done.

By the way, as is well known in VTRs, the magnetic tape 3 is wound around the rotating drum 1 at an angle slightly larger than 180° in order to prevent fluctuations in the relative speed between the tape head and mechanical precision. The video signal is A-burlap recorded by simultaneously scanning the magnetic tape 3 for a period of about 1" (T1 is the horizontal synchronization period), and during playback, the two rotating heads H+ , H2, the reproduction output of one rotary head is switched to the reproduction output of the other rotary head at a predetermined switching point where reproduction outputs are simultaneously obtained from H2. For this reason, 22-1 rotary transformers 22 and 23 are required for each rotary head 1''1°H2.

On the other hand, the frequency division multiplexed signals of the first and second FM audio signals are not transmitted during the period when the switch SWO is connected to the contact point ■;
This corresponds to the period in which the magnetic tape 3 is simultaneously scanned by 1 and (A2) and the extremely short period before and after that. Therefore, the rotary heads t-L+ and HO2 are simultaneously scanning the magnetic tape 3. During the period and a short period before and after the period, the frequency division multiplexed signals of the first and second FM audio signals are not supplied to either the rotating heads HAI or HO2,
The frequency division multiplexed signal is supplied only during the period when only one of the rotary heads of HA+ and HO2 is scanning the magnetic tape 3, and the frequency division multiplexed FM audio signal is recorded by the rotary head. . Also, during playback, since the audio track is recorded only during the period when either one of the rotating heads H△1 and HO2 is scanning the magnetic tape 3''2, the reproduced FM audio signal is transmitted to either of the rotating heads H△1 and HO2. 1"A1 or tIA2 only. Therefore, according to the present invention, even if there are two rotary heads HA1 and HO2 for audio signal reproduction, only one rotary transformer is required as shown at 18 in FIG. 3 and FIG. 7, which will be described later.

How to use: The standard color video signal that enters the input terminal 7 is supplied to a luminance signal recording system 19 and a carrier color signal recording system 20, where it is separated into a luminance signal and a carrier color signal. For example, the sync chip level is 3.4M
The FM luminance signal is converted into an FM luminance signal having a carrier frequency shift such that the white peak level is 4.4 MHz, and is extracted from the carrier color signal recording system 20.
The signal is frequency-converted to a band lower than the band of the Mfli degree signal, and is extracted as a low-frequency converted carrier color signal that has undergone processing such as known phase shift processing to prevent crosstalk. The above FM luminance signal and e.g. color subcarrier frequency 6
The 29 kHz low frequency conversion carrier color signal is supplied to the mixing circuit 21, frequency division multiplexed, and then supplied to the rotary heads H+ and H2 via the rotary 1 to the lance 22, 23, respectively.

FIG. 5 shows the information recorded on the magnetic tape 3 by the method of the present invention.
An example of the frequency spectrum of each signal to be reproduced is shown.

In the figure, FM-Y indicates the frequency spectrum of the FM luminance signal taken out from the luminance signal recording system 19, and C indicates the frequency spectrum of the low-pass converted carrier color signal taken out from the carrier color signal recording system 20. . Further, A+ and A2 indicate the frequency spectra of the first and second FM audio signals, respectively. As shown in FIG. 5, the bands of the first and second FM audio signals are selected to be close to the lower limit frequency 11 of the FM luminance signal, and are recorded at the saturation level.

Next, the tape pattern in the method of the present invention will be explained. Now, suppose that recording of the frequency division multiplexed signals of the first and second FM audio signals is started on the magnetic tape 3 by the rotary head HAI, and an audio track that is inclined with respect to the longitudinal direction of the tape begins to be recorded. , from the time when the rotation period of the rotary drum 1 at the angle θ shown in FIG. A video track in which a frequency division multiplexed signal consisting of the FM luminance signal and the low frequency conversion carrier color signal is recorded begins to be formed at different positions on the side.

Rotating head 1” Audio track by A1 and rotating head H
1 are formed at the same time with a certain time difference, and when the rotary head HAI comes near the guide ball 4b shown in FIG.
After the recording of the book's audio track is finished, the rotary head 1l
An audio track starts to be recorded by A2, and after a certain period of time, a video track starts to be recorded by the rotary head 1''2.

Here, the position where the rotary head H2 records and forms the video track is one track pitch downstream of the video track recorded and formed by the rotary head H+, and there is already one audio track there. A track is being recorded. Therefore, the rotary head H2 records and forms a video track superimposed on one audio track that has already been recorded. Here, the audio track has A1. Low frequency first and second as shown in A2
FM audio signals are recorded, but since these FM audio signals have relatively long recording wavelengths, they are recorded deep into the magnetic layer of the magnetic tape 3 at a saturation level.

On the other hand, among the video signals recorded superimposed on the audio track, the FM luminance signal has a high frequency as shown by FM-Y in FIG. Since the FMB voice signal is mainly recorded on the FMB voice signal, the FMB voice signal that has already been recorded is recorded without almost erasing it. On the other hand, since the low frequency conversion carrier color signal has a lower frequency than the FM audio signal as shown by C in FIG. If you record the areas where records are formed,
This results in substantially erasing the edge FM luminance signal. However, while the FM audio signal is recorded at the saturation level as described above, the low-frequency conversion carrier color signal that is recorded later is recorded at a level lower than the saturation level. The degree of erasure of the FM audio signal by the color signal is not so large, and the FM audio signal remains at a reproducible level.

Therefore, even if a video track is recorded and formed by the rotary head H2 over an already recorded audio track, the FM audio signal is recorded at a playable level, and the low frequency conversion carrier color signal and FM luminance signal are also recorded. It will be recorded at the same magnetic tape position.

At a point slightly earlier than the recording of the video track by the above-mentioned rotary head 1''2 is completed, the rotary head HAI is again used to record the audio track at a position that is one track pitch higher than the audio track recorded by the rotary head)-l A2. The audio track will begin to be recorded.

In this way, the rotating head 1 is placed on the magnetic tape 3.
A1 and 1''A2 form an audio track in which an FM audio signal is recorded at one track pitch, and rotary heads H+ and H2 form a low frequency conversion carrier color signal and an FM audio signal.
A video track on which a luminance signal is recorded is formed by one track pitch, and the rotating head 1"2. H+ causes a video track to be recorded and formed to overlap the already recorded audio track.

FIG. 6 is a diagram showing an example of a tape pattern in the method of the present invention, in which among the tracks inclined with respect to the longitudinal direction of the magnetic tape 3, for example, the slope 1 shown with diagonal lines at the lower left
〜Rack indicates the track where the audio track recorded and formed by the rotary head HA2 and the video track recorded and formed by the rotary head H1 are respectively recorded overlappingly, and the inclined track with diagonal lines downward to the right is the track recorded by the rotary head. 1” A1
This shows the track position where the audio track and the video track recorded and formed by the rotary head] 2 are recorded in an overlapping manner. Further, TW is the track width of one track, and here both the audio track and the video trough have the same track width, and TP indicates 1 to rack pitch. Here, since no guard band is formed between adjacent tracks, the track pitch TP and the track width T
Equal to W. Further, each track records a video signal for one field. Further, in FIG. 6, Tc indicates a control signal recording track, 29-TA indicates an audio signal recording track, and explanations of these recording systems and reproduction systems will be omitted as they are not directly related to the gist of the present invention. do. Note that the above-mentioned track TA is a track that is directly recorded with a fixed head without frequency modulating the audio signal, as in the past, and as a result, when the magnetic tape 3 is played back with a conventional VTR, the track TA is Audio signals can be played back.

In the above embodiment, audio signals compressed by 1.2 times in time are recorded in the adjacent audio tracks 1 to 6 shown in FIG. The recorded audio signal for a certain period of the audio track (indicated by T+ and T2 in FIG. 4) and the recorded audio signal for a certain period from the beginning of the audio track recorded later are audio signals having the same audio information. (In other words, the audio signal is recorded in a so-called overlap manner.)

Furthermore, as described above, during a certain period when the switch SWC is connected to the contact point (2), the time compressed audio signal is not output, and therefore the first and second FM audio signals 30- are not recorded. The first and second FM audio signals will be recorded only within the range indicated by .

Note that, based on the range indicated by RV in FIG. 6, a video signal for one field is recorded in the entire length of each track.

Next, to explain the reproducing system according to the present invention, FIG. 7 shows a block diagram of an embodiment of the reproducing system according to the present invention.

In the same figure, the same components as in FIG. 3 are designated by the same reference numerals. In FIG. 7, the rotating heads HA+, 1-(A
2 alternately scans tracks in which audio tracks and video tracks are recorded in an overlapping manner (hereinafter referred to as overlapping recording tracks for convenience of explanation), which are indicated by diagonal lines in FIG. As mentioned above, one of the adjacent audio tracks is recorded, for example, by a rotary head HA+ with an azimuth angle of 130 degrees, and the video 1 to rack recorded overlapping this audio track is For example, the azimuth angle is -6°
Since this is a track recorded by the rotary head 1-12, when the rotary head HA+ scans this overlapping recording track, only the first and second FM audio signals are reproduced due to the azimuth loss effect. The other rotating head 1-
Similarly, when 1Δ2 scans the next overlapping recording track, only the first and second FM audio signals are reproduced.

Further, since the adjacent overlapping recording tracks on the magnetic arp 3 are tracks recorded by rotary heads having different azimuth angles, when the above-mentioned rotary head 1''A1 or 11A2 scans overlapping recording tracks, the adjacent overlapping recording tracks It is possible to prevent previously recorded FM audio signals from being reproduced as crosstalk.

In this way, the first and second FM audio signals as shown in FIG. A left channel audio signal reproducing system 26 and a right channel audio signal reproducing system 27 respectively.
are supplied respectively. Both reproduction systems 26 and 27 differ only in the carrier frequency of the reproduced FM audio signal demodulated by the FM demodulator, and have substantially the same configuration, so only the reproduction thread 26 will be explained. The reproduced first and second FM audio signals are supplied to the 1M demodulator 28 in the reproduction string 26, where only the first [M audio signal is frequency-selected and FM demodulated, and then low-frequency Filter 29 removes unnecessary frequency components. The time-compressed left channel audio signal extracted from the two low-pass filters is supplied to switch SWd.

In use, the clock pulse generator 31 generates clock pulses with repetition frequencies of 1.2f and f which are phase synchronized with the drum pulses received at the input terminal 30 as shown in FIG. 8(B). Switches SWf and SWo are switch SWd
, SWe, etc., are composed of electronic switch circuits,
Using switching pulses from a switching pulse generation circuit (not shown), clock pulses with repetition frequencies of 1.2f and f are applied to the BBDs 32 and 33 in phase synchronization with the drum pulses by switching alternately at a predetermined timing. In addition, the switch SWd has contacts d3,
It is alternately switched every one field period. Here, the contacts ■ and ■ of the switch SWd are connected to the input terminals of B33-BD32.33. Further, the time-compressed left channel audio signal input to the common contact of the switch 5W (I) is supplied to the BBD 32 or 33 by the switch SWd.

FIG. 8(E) shows the switching timing of this switch SWd.

Furthermore, the contacts of the switch SWe are connected to the output terminal of the BBD32.33, and as shown in FIG. The contact ■ is connected to the contact ■ after a predetermined fixed time T3 after switching from the contact ■ to ■, and the switch SWd is controlled to be connected to the contact ■ after a fixed time T3 after switching from the contact ■ to ■.

As a result, during one field period when the switch 5Wfl shown in FIG. 8(E) is connected to the contact point ■, the BBD3
A time compressed audio signal is written into the BBD 33 using a clock pulse with a repetition frequency of 1.2 as schematically shown in FIG. It will be done. During the next one field period when the switch SWd shown in FIG. A channel audio signal is written, and the time-compressed left channel audio signal written in the immediately previous one field period by the BBD 32 is read out using a clock pulse with a repetition frequency of 1. At this time, the audio signal of the overlap recording session is read out over a period indicated by T4 in FIG. 8(D). In this way, from the BBr) 32, the left channel audio signal, which has been time-expanded by 1.2 times and restored to the original audio pitch, for a little over one field, is transmitted for a period of just over one field (
1 field + T4) as schematically shown in FIG. 8 (D>).

B. When the reading of BD32 is completed, the reading of BBD3 is completed.
As shown in Figures 3 to 8 (D), in the same way as above, the left channel audio signal, which has been time-expanded by 1.2 times and restored to the original audio pitch, is over one field long. The data is read out over a period of .

Switch swe is BBD32. Or at 33, the frequency [glue ": 1] The point J at which the pulse begins to be applied is shortened for a short period T3 (T3 < T4), and then the contact point ■.

or ■, the reproduced left channel audio signal read from the BBD 32.33 is output to the output terminal 35 through the switch SWe and the low-pass filter 34, respectively.

In this way, the output *η1 child 35 has BBD32°3
The left channel audio signals, which are read out after being alternately time-stretched from 3 and restored to the original audio pitch, are synthesized in a time-series manner and are continuously extracted.

Also, from the right channel audio signal reproduction system 27, the right channel audio signal, which has been restored to the original audio pitch and read out in the same manner as described above, is continuously outputted to the output terminal 36.

Here, in this embodiment, the audio signal is time-compressed by 1.2 times and recorded in an overlapping manner.
, (F), during reproduction, the outputs of the BBDs 32 and 33 are switched approximately at the center of the period T4 during which the overlap-recorded audio signals are reproduced, so that uneven running of the magnetic tape 3, Rotating head HA1
．． Day A2゜] Due to uneven rotation of 1 and H2, the tape
Even if the relative linear velocity between the heads varies and a phase variation (time axis variation) of the drum pulse occurs, the reproduced audio signal can always be switched within the reproduction period of the overlap recorded audio signal. Therefore, even if a phase change occurs in the drum pulse due to a disturbance, problems such as discontinuity of the reproduced audio signal and interruptions do not occur, and the reproduced audio signal is always extracted continuously.

When the rotary head IAI scans the overlapping recording tracks, the rotary head 11 scans the overlapping recording tracks indicated by diagonal lines downward to the left in FIG. 6 after a slight fixed time delay. As a result, the reproduction signal of the video track reproduced by the rotary head H1 is transferred to the rotary transformer 22.
The signal is supplied to a luminance signal reproducing system 40 and a carrier color signal reproducing system 41 through a preamplifier 37° and a switch circuit 39 connected to terminal a, respectively. The luminance signal reproduction system 40 is a reproduction F
After dividing the M luminance signal into 111lt-waves, it is FM demodulated to obtain a reproduced luminance signal of the original band, which is output to the mixing circuit 42. In addition, the carrier color signal reproducing system 41 separates and waves the reproduced low-frequency converted carrier color signal and returns it to the original band, and also reproduces the low-frequency converted carrier color signal from the adjacent overlapping recording tracks as a single cross. The carrier color signal is removed using a comb filter to extract only the reproduced carrier color signal of the scanning track, which is output to the mixing circuit 42. Mixing circuit 4
2 mixes both of the above signals and outputs it to the output terminal 43 as a reproduction standard color video signal.

When the above-mentioned scanning of each track of the rotary head 1-IA+ and H+ is completed, the switch circuit 39 is then switched to the terminal side, and each overlapping recording track is scanned by the rotary head 1''A2゜1-12. begins to be

As a result, the rotary head H2 moves to the previously recorded F of the audio track in the overlapping recording track due to the azimuth loss effect described above.
The M audio signal is not reproduced, but only the recorded green signal of the video track is reproduced. That is, a frequency division multiplexed signal consisting of a low frequency conversion carrier color signal and an FM luminance signal recorded on the overlapping recording track is reproduced and outputted from the rotating head 1'' 2, and this reproduced frequency division multiplexed signal is transmitted to the rotary transformer 23.゜Preamplifier 38. The signals are supplied to a luminance signal reproducing thread 40 and a conveying color signal reproducing system 41 through respective switch circuits 39 connected to the terminal side. Luminance signal regeneration thread/'10 and conveyance color signal regeneration system 4
1 performs the same operation as described above, so the mixing circuit 42
The video signal for one field recorded on the overlapping recording track is output as a playback standard color video signal to the output terminal /13. As described above, according to the present embodiment, the overlapping recordings 1 to racks formed by the rotary heads H2 and HAI or l''+ and HA2, which have different azimuth angles from each other, are recorded by the rotary heads 1 of the respective azimuth angles. -12 and 1-IAI or 1-11 and 1-1Δ
2, the FM audio signal, the low-frequency converted carrier color signal, and the [M luminance signal] are simultaneously recorded and reproduced using the same rotary head. Mutual interference due to beats with the FM luminance signal hardly occurs. Therefore, color video signals and audio signals can be reproduced with high quality.

Next, to explain the second embodiment of the method of the present invention, the ninth embodiment
The figure shows a tape pattern recorded and formed by the second embodiment of the method of the present invention. In the figure, the same components as in FIG. 6 are designated by the same reference numerals. In FIG. 9, adjacent overlapping recording tracks are arranged by rotary heads HA having different azimuth angles.
I, HA2°Hl, and 1-12 are recorded in the same manner as in Fig. 6, but in this embodiment, the two left and right channel audio signals are each compressed in time by a factor of 2.2. For example, it is a time-division signal that is synthesized in a time-series manner alternately every 0.5 field period or less, and is obtained by frequency modulating a single carrier frequency (for example, 1.1 MH2) with this time-division signal. The frequency modulated audio signal is sent to the rotary head HA+, l.
'' A2 is recorded and this is reproduced.

In FIG. 9, within the range indicated by RA, the track portions indicated by diagonal lines with sparse intervals are recorded with, for example, the FM signal of the time-compressed left channel audio signal, and the track portions indicated by diagonal lines with close intervals are recorded. The FM signal of the time-compressed right channel audio signal is recorded.

The reproduction system for reproducing a magnetic tape having the tape pattern shown in FIG.
The time is expanded twice and the audio signals of the left and right channels of the original audio pitch are extracted.

FIG. 10 does not show the tape pattern recorded and formed by the third embodiment of the method of the present invention. In the figure, the same components as in FIG. 6 are designated by the same reference numerals. In FIG. 10, each inclined track is a track in which an audio track and a video signal are respectively recorded and formed, which is the same as in the first and second embodiments, but in this embodiment, two rotating head tracks are used. IA
The azimuth angles of I and IA2 are the same angle (for example -3
0°), and the audio signals of the two left and right channels are each compressed in time by a factor of 4.4, and outside of time compression 41
- After transmitting the channel audio signal for a period of a little less than 0.5 fields, nothing is transmitted for the next period of a little more than 1 field, and for the next period of a little less than 0.5 fields, time compression is performed. After transmitting the channel audio signal, the time-compressed left channel audio signal is repeatedly transmitted during the next 0.5 field period,
In such a time division multiplexed signal, a single carrier frequency (e.g. 1
．． The difference is that the audio signal obtained by frequency modulating the 1MH2) is recorded by the rotary head 1-IAl, HA2, and is reproduced.

Therefore, according to this embodiment, within the range shown by <RV as shown in FIG. As shown by diagonal lines, for example, the FM signal of the time-compressed left channel audio signal is recorded, and the FM signal of the time-compressed right channel audio signal is recorded in the track portion shown by the diagonal lines, which is located approximately in the second half of the other audio track. recorded. Therefore, the track portions adjacent to both sides of the FM audio signal recording track portion are video track portions where only the video signal number 42- shown in white in Figure 10 is recorded, and as a result, there is essentially one audio track. A guard band corresponding to the track width TW of the video track is formed. Therefore, even if the rotary heads HA+, l'A2 have the same azimuth angle surface, the existing recording of the adjacent overlapping recording track will be canceled when the overlapping recording track is reproduced. FM audio signals are not reproduced as crosstalk.

Modifications The present invention is not limited to the above embodiments, but also includes the following various modifications.

That is, the first . The second FM audio signal may be modulated by a sum signal and difference signal of the left and right two channel audio signals. However, in that case, a matrix circuit is required in the recording/reproducing system. Furthermore, the audio signal is not limited to a two-channel stereo audio signal, but may be an audio signal of three or more channels. Furthermore, the audio signal may be recorded and reproduced in the form of a digital signal.

Furthermore, the rotating head HA1. The track width of HA2 may be larger than that of the rotary head hl+,t''2. This is because, in this case as well, a part of the video track is formed as a guard band between adjacent audio tracks, although the width is smaller than the 1-to-rack width of the video track. Also BB
In place of Dlo, 11, 32 and 33, other charge transfer elements such as a charge coupled device (COD) or digital memory may be used to perform time compression and expansion.

Furthermore, by making the falling and rising edges of the reproduced audio signal switched at the time of switching during the overlap period relatively gentle and creating a fade-out and fade-in configuration, it is possible to reduce switching noise, especially in the high frequency range. .

Effects As described above, according to the method of the present invention, the FM audio signal is recorded by a dedicated rotating head, which is different from the conventional method in which the FM audio signal and the FM video signal are multiplexed and recorded and played back by the same rotating head. Compared to conventional methods, mutual interference caused by beats between carrier frequencies can be greatly reduced, and moiré on the playback screen can be almost eliminated. Since it is recorded in the same position as the video track, compared to recording the video track and audio track without overlapping, the recording and playback time is not reduced by 1, and the audio signal is N times ( N is the number of fields of the video signal recorded on one track). Because the time is compressed to more than the number of fields of the video signal recorded on one track, the rotary transformer can be configured with one rotary transformer even though there are two rotary heads for audio signal recording. Compared to the case where audio signals are recorded using a dedicated rotary head and two rotary transformers, the number of rotary transformers can be reduced by one, so the configuration can be simple and inexpensive, and the audio signals can be time-compressed. By switching during the playback period of the overlap-recorded audio signal, the playback audio signal will not be interrupted even if the relative speed between the rotating head and the tape changes, and disturbances will be avoided. It is possible to stably reproduce an audio signal in a continuous 45-times-per-second range, and it can also time-compress the audio signal by more than 2N times and time-division multiplex it, and use the time-division multiplexed signal to convert a single carrier frequency into a frequency. When the frequency-modulated audio signal obtained by modulation is recorded using two rotary heads, the band required for recording and reproducing the audio signal can be narrowed, and the frequency modulator and FM demodulator can be configured with only one each. It has features such as the ability to

[Brief explanation of the drawing]

1 and 2 are a plan view and a side view, respectively, showing an embodiment of the head arrangement in the method of the present invention, and FIG. 3 is a block system diagram showing an embodiment of the recording system of the method of the present invention, and FIG. 4(A) to (F) are diagrams for explaining the operation of each part of the block system shown in FIG. 3, respectively, and FIG. 5 is a diagram showing an example of the frequency spectrum of a signal recorded and reproduced by the method of the present invention. , FIG. 6 is a diagram showing an example of a tape pattern recorded and reproduced by the method of the present invention, FIG. 7 is a block system diagram showing an embodiment of the reproduction system of the method of the present invention, and FIGS.
(F) is a diagram for explaining the operation of each part of the illustrated block system 46 in FIG. 7, and FIGS. 9 and 10 respectively show tape patterns according to the second and third embodiments of the present invention. It is. 1... Rotating drum, 3... Magnetic tape, 5, 6...
・Audio signal input terminal, 7...Video signal input terminal, 8.
・Left channel audio signal reproduction system, 10, 11, 32° 33 ・Bucket 1~・Brigate device (BBD
), 12.30...Drum pulse input terminal, 13°3
1... Clock pulse generator, 15... Frequency modulator, 16, 21. '12... Mixing circuit, 17... Right channel audio signal recording system, i8, 22.33... Rotary transformer, 26... Left channel audio signal reproducing system, 27... Right channel audio signal reproducing system Series, 28・
...FM demodulator, 35...Left channel audio signal output terminal, 36...Right channel audio signal output terminal, 4
3... Reproduction color video signal output terminal, HA+. 11A2...Rotary head for recording and reproducing audio signals, G11
゜H2...Rotary head for recording and reproducing video signals. -4l-

Claims (1)

[Scope of Claims] (1) A rotary body on which a magnetic recording medium is attached and wound over a certain angle range, and a plurality of video signal recording rotary heads having mutually different azimuth angles and the video signal recording rotary body. Two audio signal recording rotary heads with different azimuth angles from the head and different azimuth angles from each other are installed respectively, and the recording head is slightly more than N times larger (N is the number of fields of the video signal recorded on one track). The frequency-division multiplexed signals of the frequency-modulated audio signals of the multiple channels, each of which is time-compressed and has a different carrier frequency, are recorded for each track scanning period. The audio signal is supplied to a rotary head, and the rotary head for recording the audio signal forms an audio track in which the frequency modulated audio signals of the plurality of channels are recorded on the traveling magnetic recording medium at one track pitch, and the rotary head for recording the video signal A multiplex recording system characterized in that a video track on which a video signal is recorded on the magnetic recording medium is formed in one track bit, and the video track is recorded over the already recorded audio track. (2) The video signal recorded by the video signal recording rotary head includes a frequency-modulated luminance signal and a low-frequency conversion carrier color signal that occupies an empty band lower than the frequency-modulated luminance signal band. A frequency division multiplexed signal according to claim 1, characterized in that the band of the frequency modulated audio signal of the plurality of channels is selected and recorded near the lower limit frequency of the frequency modulated luminance signal. Recording method. G) The azimuth angle of the two audio signal recording rotary heads is the azimuth angle J of the video signal recording rotary head.
2. The multiplex recording system according to claim 1 or 2, characterized in that the size of the recording medium is selected to be sufficiently large. (4) A plurality of video signal recording rotary heads having mutually different azimuth angles are mounted on a rotating body on which a magnetic recording medium is attached and wound over a certain angular range, and the video signal recording rotary heads have azimuth angles different from each other. By installing two audio signal recording rotary heads that are different and have different azimuth angles, the time is compressed to just over 2N times (where N is the number of fields of the video signal recorded on one track). The first channel has two channels of audio signals with respective modulation signals. A time division multiplexed signal of the second frequency modulated audio signal is supplied to the audio signal recording rotary head every one track scanning period, and the audio signal recording rotary head transfers the first... An audio track in which a time-division multiplexed signal of the second frequency modulated audio signal is recorded is formed in one track pitch, and a video track in which a video signal is recorded on the magnetic recording medium by the video signal recording rotary head is formed in one track pitch. 1. A multiplex recording method characterized in that the video images 1 to 1 are recorded in a superimposed manner on the already recorded audio track. 6) The video signal recorded and reproduced by the video signal recording rotary head is a frequency-modulated luminance signal or a low-frequency conversion carrier color that occupies an empty band on the lower side than the frequency-modulated luminance signal band. It is a frequency division multiplexed signal with a signal,
The frequency modulated audio signals of the two channels each have the same carrier wave frequency, and the band thereof is selected and recorded near the lower limit frequency of the frequency modulated luminance signal. Recording method. (6) A plurality of rotary heads for recording and reproducing video signals having mutually different azimuth angles are mounted on a rotating body on which a magnetic recording medium is attached and wound over a certain angular range. Attach two rotary heads for audio signal recording and playback with different angles (P, N times more (However, N
is the number of fields of a video signal recorded on one track), and the audio signals of multiple channels A7 time-compressed are the respective modulation signals, and the frequency modulation of multiple channels having mutually different carrier frequencies is performed. A frequency division multiplexed signal of an audio signal is supplied to the audio signal recording/reproducing rotary head every one track scanning period, and the audio signal recording/reproducing rotary head transfers the frequency modulated audio of the plurality of channels to the traveling magnetic recording medium. An audio track on which a signal is recorded is formed with one track pitch, and a video track on which a video signal is recorded on the magnetic recording medium by the rotary head for recording and reproducing the video signal is formed on one track pitch, and the already recorded audio track is The video track is recorded in an overlapping manner, and during playback, the frequency-modulated audio signals of the plurality of channels taken out from the audio signal recording and reproducing rotary head are demodulated for each channel, and the time is expanded by more than N times. A multiplex recording/reproducing method characterized in that the reproduced audio signals of the plurality of channels at the original audio pitch are continuously extracted. ■ The video signal recorded and reproduced by the rotary head for video signal recording and reproduction consists of a frequency-modulated luminance signal and a low-frequency band that occupies an empty band lower than the frequency-modulated luminance signal band. It is a frequency division multiplexed signal with a converted carrier chrominance signal, and is characterized in that the band of the frequency modulated audio signal of the plural channels is selected near the lower limit frequency of the frequency modulated luminance signal, and is recorded and reproduced. A multiplex recording/reproduction method according to claim 6. S) The azimuth angles of the two rotary heads for recording and reproducing audio signals are different from each other and are selected to be sufficiently larger than the azimuth angle of the rotary head for recording and reproducing video signals. The multiplex recording and reproducing method according to item 6 or 7. (9) A plurality of rotary heads for recording and reproducing video signals having mutually different azimuth angles are mounted on a rotary body on which a magnetic recording medium is attached and wound over a certain angular range. Two rotary heads for audio signal recording and playback, each having a specific angle and a different azimuth angle, are installed, respectively, and the number of fields of the video signal recorded on one rack is 2N times more (N is the number of fields of the video signal recorded on one track). ) are time-compressed two-channel audio signals as the respective modulation signals. A time-division multiplexed signal of the second frequency modulated audio signal is supplied to the audio signal station recording/reproducing rotary head for each track scanning period, and the audio signal recording/reproducing rotary head:
The first. 1 audio track recording the time division multiplexed signal of the second frequency modulated audio signal.
forming a video track with a track pitch and recording a video signal on the magnetic recording medium by the rotary head for recording and reproducing the video signal with a rack pitch;
The video track is recorded in an overlapping manner on the already recorded audio tracks 1 to 1, and during playback, the first and second frequency modulated audio signals taken out from the audio signal recording/reproducing rotary head are demodulated, and each A multiplex recording/reproduction method characterized by extending the time by more than 2N times for each channel and successively extracting the reproduced audio signals of the two channels at the original audio pitch. (10) The video signal recorded and reproduced by the rotary head for video signal distribution and reproduction consists of a frequency-modulated luminance signal and a low frequency band that occupies an empty band lower than the frequency-modulated luminance signal band. a frequency division multiplexed signal with a converted carrier chrominance signal, the frequency modulated audio signals of the two channels each have the same carrier frequency, and the band thereof is selected near the lower limit frequency of the frequency modulated luminance signal and recorded; 10. The multiplex recording and reproducing method according to claim 9, wherein the multiplex recording and reproducing method is characterized in that this is reproduced.