JPH0157555B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic recording/reproducing device, and in particular to a magnetic recording/reproducing device, in which a frequency modulated wave obtained by frequency modulating an audio signal is changed over its carrier frequency every one track scanning period. Track shift information is obtained from the above-mentioned frequency modulated wave which is recorded on the same track as the video signal and reproduced as crosstalk from a track adjacent to the track to be scanned, and at least tracks the video signal recording/reproducing rotary head. The present invention relates to a device for recording and reproducing while performing.

Prior Art In a helical scanning magnetic recording/reproducing device (VTR), a plurality of rotating heads, for example two rotating heads, are attached at equal angular intervals to a rotating body such as a rotating drum, and the rotating body has an angular range of, for example, over 180°. A magnetic tape is run while being wound in parallel, video signals are recorded on the magnetic tape by a rotating head, audio signals are recorded by a fixed head installed in the middle of the magnetic tape running path, and during playback, It is well known that a rotary head reproduces a video signal and a fixed head reproduces an audio signal.

On the other hand, the recording and reproducing time of VTRs has been increasing in recent years, and the running speed of magnetic tapes has been decreasing accordingly. Furthermore, it is desired that audio signals be reproduced with higher quality. However,
Since audio signals are recorded and played back on magnetic tape by a fixed head, the mutual linear velocity between the tape and the head is low, and if the running speed of the magnetic tape is slowed down, the frequency characteristics of the video signal recorded and played back by a rotating head will be lower. However, the frequency characteristics of the audio signal deteriorated significantly, making it impossible to record and reproduce 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 rotary head for video signal recording and reproduction, and the same is reproduced. According to this recording and reproducing method, audio signals are recorded and reproduced by a rotating head on a magnetic tape with a high mutual 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 a magnetic tape, it is possible to record and reproduce audio signals with much higher quality.

On the other hand, especially simple VTRs for home use (hereinafter referred to as "home video recorders")
The recording and reproducing density of the VTR (VTR) has been improved by improving the magnetic tape and increasing the sensitivity of the rotary head, and the recording and reproducing density has been increased even further by improving the tape speed and track pitch, etc. Home VTRs with long recording and playback times of 6 hours have been commercialized, which is about 1/3 of that required in the case of normal use. However, in home VTRs, where the tape running system has been simplified to reduce costs, it is difficult to follow the curves of the video track and stably maintain the required tracking accuracy, especially when using other It has been difficult to stably maintain the above-mentioned required tracking accuracy during so-called compatible playback in which a magnetic tape recorded on a home VTR is played back on another home VTR.

Therefore, as a method to solve the above-mentioned tracking problem associated with high-density recording and playback, and also to eliminate noise bars during special playback (trick play) such as slow-motion playback, still playback, and fast-motion playback, we have developed a rotating head. In recent years, home VTRs have been actively developed that are equipped with a head moving mechanism that displaces the rotary head on a plane perpendicular to its rotating surface and displaces the rotary head in a direction perpendicular to the longitudinal direction of the track (that is, in the width direction of the track). ing.

A platform equipped with such a head moving mechanism
In VTR, it follows the curve of the track,
Alternatively, in order to make the track follow the head scanning locus during special playback, which is performed at a tape running speed different from that during recording, information on the relative shift between the track to be scanned and the rotating head currently scanning the magnetic tape (track shift It has a tracking servo circuit that detects the track deviation information) and generates a tracking error signal based on the tracking error signal to correct the tracking deviation of the rotary head.Accurately detecting the above tracking deviation information is the key to correcting the tracking deviation. It is extremely important for

In this way, the tape running speed is slowed down to enable especially long recording and playback.
In VTR, high-quality reproduction of audio signals and
Maintaining stable tracking accuracy is a problem, but by converting the audio signal into a predetermined signal format, superimposing it on the video signal, recording it on the magnetic tape with the same rotating head, and playing it back, the tape running can be improved. It is possible to reproduce audio signals with high quality even at slow speeds, and it also has the ability to detect track deviations.
Continuously record four types of pilot signals for each track and play them back to detect the envelope detection level, or rotate the rotating head at 480Hz during playback.
Track deviation can be detected accurately by swinging the head in the width direction of the track and detecting fluctuations in the reproduced FM level. can be secured.

Problems to be Solved by the Invention However, as a method for detecting the track deviation information, there are four types of methods in which the frequency is switched for each track recording unit so that adjacent tracks are recorded at different frequencies. The conventional method is to record a pilot signal continuously for each track, discriminate the frequency of the reproduced pilot signal during reproduction, and detect track deviation information from the reproduction level.
It requires a special pilot signal,
Therefore, an additional circuit such as a pilot signal generator is required.

On the other hand, during playback, the rotating head is vibrated in the width direction of the track at approximately 480 Hz, and track deviation is detected from fluctuations in the playback FM level of the information signal recorded in the form of a frequency modulated wave signal (FM signal) on the track. There was also a conventional method to do this, but this conventional method had a problem in that the influence of fluctuations in the reproduced FM level could appear in the FM demodulated signal.

In addition, in order to record and play back audio signals with high quality,
Conventionally, as mentioned above, an audio signal is converted into a predetermined signal format and superimposed on a video signal, and this superimposed signal is simultaneously recorded and played back by the same rotating head, which causes beats to occur between carrier frequencies. , the beat interferes with the playback screen (moiré)
There was a problem in that it caused

Therefore, the present invention provides an audio track in which a first rotary head records a frequency-modulated audio signal switched to a different carrier frequency for each track scanning period, and a video track in which a video signal is recorded in a second rotary head. By overlapping these tracks, high-quality audio signals can be recorded and played back.Furthermore, both during recording and playback, tracks can be tracked based on frequency modulated wave signals played back from adjacent tracks as crosstalk. It is an object of the present invention to provide a magnetic recording/reproducing device capable of tracking control of at least the second rotary head by obtaining deviation information.

Means for Solving the Problems The present invention provides a recording system including a plurality of rotating heads for recording video signals having mutually different azimuth angles on a rotating body on which a magnetic recording medium is spliced and wound over a certain angle range. The video signal recording rotary head is a magnetic recording device in which a plurality of audio signal recording rotary heads having different azimuth angles are respectively attached, and the carrier wave frequency corresponds to one track scanning period of the audio signal recording rotary head. means for generating and serially outputting a frequency-modulated audio signal whose frequency is switched to a different frequency each time; The first record formed by the head
and a second recording means for recording and forming a video track on which a video signal has been recorded by the video signal recording rotary head, superimposed on the already recorded audio track of the magnetic recording medium. , the audio track adjacent to both sides or one side of the video track to be reproduced, which is included as crosstalk in the reproduced signal obtained by reproducing the already recorded signal of the magnetic recording medium by the rotary head for video signal recording and reproduction; filter circuit means for frequency-selecting and outputting only the reproduced frequency-modulated audio signal; and a rotary head for video signal recording and reproduction based on the level of the frequency-modulated audio signal taken out from the filter circuit means. and a head moving mechanism for displacing a rotary head for recording and reproducing video signals in the track width direction so that the track deviation is minimized based on the track deviation information. Each example will be described below.

Embodiment FIGS. 1 and 2 each show an embodiment of the head arrangement relationship, etc. in the method of the present invention. In both figures, the same components are designated by the same reference numerals. In both figures, on the rotating surface of a rotating drum 1, which is an example of a rotating body, there are rotating heads _H1 and _H2 for recording and reproducing video signals.
are installed facing each other at 180° intervals,
Further, rotary heads H _A1 and H _A2 for recording and reproducing audio signals are fixedly mounted at positions preceding the rotary heads _H1 and _H2 by an angle θ in the rotation direction, respectively. The rotary heads _H1 and _H2 are mounted at the same height as shown in FIG. 2, and are mounted at a height d higher than the rotary heads H _A1 and H _A2 . The rotating drum 1 is disposed so that its lower surface faces the upper surface of the fixed drum 2 by a small distance, and the magnetic tape 3 is guided by guide poles 4a and 4b over an angular range of over 180 degrees. 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.

In addition, the rotating heads H ₁ and H ₂ have different azimuth angles, and the rotating heads H _A1 and H _A2 have different azimuth angles.
is selected to be an azimuth angle that is sufficiently larger than the azimuth angles of the rotating heads _H1 and _H2 . As will be described later, since the video track recorded and formed by the rotary heads H ₂ and H ₁ and the audio track recorded and formed by the rotary heads H _A1 and H _A2 are recorded and formed at the same position, both rotary heads H ₂ It is advantageous that the azimuth angle difference between H _A1 and H A1 and the azimuth angle difference between H ₁ and H _A2 be larger than that between the rotary heads H ₁ and H _A1 or H ₂ and H _A2 , respectively. In addition, in order to reproduce the audio signal with less mutual interference with the video signal, the azimuth angle of the rotating heads H _A1 and H _A2 should be set as follows.
It is necessary to make the azimuth angle different from that of the rotating heads H ₁ and H ₂ , and it is desirable to select the azimuth angle to be sufficiently larger than the azimuth angle of the rotating heads H ₁ and H ₂ so that the above-mentioned mutual interference can be minimized for reproduction.
In view of the above points, the azimuth angle of the rotating head _H1 is selected to be -6°, that of _H2 is +6°, that of H _A1 is -30°, and that of H _A2 is +30°.

Furthermore, since the video track recorded and formed by the rotary heads H ₂ and H ₁ and the audio track recorded and formed by the rotary heads H _A1 and H _A2 are recorded and formed at the same position, respectively, the rotary heads H A1 and H _A2 are used as described above.
H _A2 is provided at a position that precedes the rotating heads H ₁ and H ₂ by an angle θ in the rotation direction and is lower by a height d. As an example, the diameter of the rotating drum 1 is 62 mm, θ is 55°, and d is 18 μm. Note that since the height positions differ by the above distance d, the start end of the audio track recorded and formed by the rotary heads H _A1 and H _A2 is higher than the start end of the video track recorded and formed by the rotary heads H ₂ and H ₁ .
Although there is a deviation of about 18 μm, this deviation is extremely small and can be virtually ignored. Furthermore, the rotating heads H ₁ , H ₂ , H _A1 and H _A2 are each attached to a head moving mechanism such as a bimorph, and are configured to be displaced in the track width direction.

Next, to explain the signal processing system of the present invention,
FIG. 3 shows a block system diagram of each embodiment of the recording system of the present invention. In the figure, the same components as 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 audio signal separately, and input terminal 7 receives a standard color video signal. However, the first embodiment of the device of the present invention is an example in which a single channel audio signal is input to the input terminal 5, and this first embodiment will be described first.
The audio signal from the input terminal 5 is transmitted to a frequency modulator 8,
9, 10 and 11 simultaneously, and the frequency
Frequency modulation of f ₁ (e.g. 1.1MHz), f ₃ (e.g. 1.6MHz), f ₄ (e.g. 1.85MHz) and f ₂ (e.g. 1.35MHz) carrier waves into a frequency modulated audio signal (FM audio signal) converted. Frequency modulator 8, 9, 1
0 and 11 respectively, the first one whose maximum frequency deviation is selected to be ±100 KHz, for example.
The second, third and fourth FM audio signals are supplied to a switching circuit 12, where the rotary heads are switched by drum pulses corresponding to the rotational phases of the rotary heads H _A1 and H _A2 generated by known means.
H _A1 and H _A2 are sequentially switched cyclically every one track scanning period, and the -FM audio signal is extracted.
Rotating head via rotary transformers 13 and 14
Supplied to H _A1 and H _A2 respectively.

On the other hand, the standard color video signal input to the input terminal 7 is supplied to a luminance signal recording system 15 and a carrier color signal recording system 16, where it is separated into a luminance signal and a carrier color signal. For example, the sync chip level is converted into an FM luminance signal with a carrier frequency shift such that the white peak level is 4.4MHz at 3.4MHz, and is extracted from the carrier color signal recording system 16 in the band of the FM luminance signal. frequency converted to a lower band than, and
The signal 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-mentioned FM luminance signal and, for example, a low frequency conversion carrier color signal with a color subcarrier frequency of 629 KHz are supplied to a mixing circuit 17 where they are frequency division multiplexed, and then passed through rotary transformers 18 and 19 to a rotating head.
Supplied to H ₁ and H ₂ respectively.

FIG. 4 shows an example of the frequency spectrum of each signal recorded on the magnetic tape 3 and reproduced by the apparatus of the present invention. In the figure, FM-Y indicates the frequency spectrum of the FM luminance signal taken out from the luminance signal recording system 15, and C indicates the frequency spectrum of the FM luminance signal taken out from the carrier color signal recording system 16.
2 shows the frequency spectrum of the low-pass transformed carrier chrominance signal extracted from FIG. Further, A ₁ , A ₂ , A ₃ and A ₄ represent the frequency spectra of the first, second, third and fourth FM audio signals, respectively. As shown in Figure 4, the bands of the first to fourth FM audio signals are
The frequency is selected near the lower limit frequency of the FM brightness signal, and is recorded at the saturation level.

Next, the tape pattern in the present invention will be explained. Now, the rotating head H _A1 is placed on the magnetic tape 3.
When recording of the first FM audio signal is started, an audio track that is inclined with respect to the longitudinal direction of the tape begins to be recorded, and from that point on, the rotating drum 1 further rotates by the angle θ shown in FIG. From the time when the period has elapsed, the rotary head _H1 tilts the audio track at the same angle as the audio track, and tilts the audio track at a different position on the upstream side of the tape with respect to the audio track.
A video track begins to be formed in which a frequency division multiplexed signal consisting of an FM luminance signal and a low frequency conversion carrier chrominance signal is recorded. An audio track by the rotary head H _A1 and a video track by the rotary head _H1 are formed simultaneously with a certain time difference between them, and when the rotary head _H1 comes near the guide pole 4d shown in _FIG . The recording of one video track by
Recording of one audio track by H _A1 has already been completed), and then a video track begins to be recorded by rotary head _H2 .

Here, the position where the rotary head _H2 records and forms the video track is a position that is one track pitch downstream of the tape from the video track recorded and formed by the rotary head _H1 ;
The audio track of the book is recorded. Therefore, the rotary head _H2 has already recorded 1
A video track will be recorded over the audio track of the book. Here, the audio track has low frequency first parts as shown by A ₁ to _{A 4} in Figure 4.
Among the fourth FM audio signals, FM audio signals are recorded, but because 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. ing.

On the other hand, among the video and video signals recorded over the audio track, the FM luminance signal is shown in Figure 4.
Since the frequency is high as indicated by FM-Y, it is mainly recorded on the surface layer of the magnetic layer of the magnetic tape 3, so that the already recorded FM audio signal is recorded without almost erasing it. On the other hand, the low frequency conversion carrier color signal is as shown by C in Figure 4.
Since the frequency is lower than that of the FM audio signal, it is recorded deep into the magnetic layer of the magnetic tape 3, so if an audio track is recorded over an already recorded area, the previously recorded FM audio signal will be omitted. It will be deleted. However, while the FM audio signal is recorded at the saturation level as mentioned 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 very large, and the FM audio signal remains at a playable level.

Therefore, even if a video track is recorded and formed by the rotating head _H2 on top of 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 at the same magnetic tape position.
The video track is recorded downstream of the tape with respect to the already recorded audio track by the rotation period of _the head mounting angle difference θ in advance of the one track scanning period in which the video track is recorded by the rotating head H2 over the already recorded audio track. An audio track begins and ends to be recorded by the rotary head H _A2 at a position one track pitch away from the side.

Then, when the rotary head _H2 comes near the guide pole 4b and finishes recording one video track,
Next, recording of the next video track is started by the rotary head _H1 at a position one track pitch away from the video track on the downstream side of the tape. Here, at the position where the video track is recorded and formed by the rotary head _H1 , one audio track has already been recorded and formed by _the rotary head H _{A2 .} Similarly, a video track is recorded and formed over the already recorded audio track.

Thereafter, by repeating the same operation as above, the rotating heads H A1 , H _A1 ,
An audio track on which an FM audio signal is recorded is formed by H _A2 with one track pitch, and a low _- frequency conversion carrier color signal and _a
A video track on which an FM luminance signal has been recorded is formed by overlapping the already recorded audio track with one track pitch.

FIG. 5 is a diagram showing an example of a tape pattern according to the present invention. Among the tracks that are inclined with respect to the longitudinal direction of the magnetic tape 3, for example, the inclined tracks t ₁ , t ₃ , which are shown with diagonal lines downward to the right, t ₅ , t ₇ ,... are
The audio tracks recorded by the rotary head H _A1 and the video tracks recorded by the rotary head H ₂ are shown as oblique tracks t ₂ , t ₄ , t ₆ , t with diagonal lines downward to the left. ₈ ,... are the audio tracks recorded by the rotating head _H2 ,
This figure shows a track on which video tracks are superimposed and recorded by the rotating head _H1 . Also, the code inside the bracket indicates the carrier frequency of the recorded FM audio signal. Also
TW is the track width of one track, and here both the audio track and the video track have the same track width, and TP indicates the track pitch. Here, since no guard band is formed between adjacent tracks, the track pitch TP is equal to the track width TW. It is also assumed that each track records a video signal for one field. Further, in FIG. 5, Tc indicates a control signal recording track, T _A indicates an audio signal recording track, and the explanation of these recording systems and reproduction threads is as follows.
Since it has no direct relation to the gist of the present invention, it will be omitted. Note that the above-mentioned track T _A is a track that is directly recorded on a fixed head without frequency modulating the audio signal, as in the past.Therefore, when the magnetic tape 3 is played back on a conventional VTR, the track T Audio signals can be played back from _A.

Next, the recycled yarn of the apparatus of the present invention will be explained. FIGS. 6 and 7 show block system diagrams of one embodiment of the recycled yarn of the apparatus of the present invention. In the figure, the same components as in FIG. 3 are designated by the same reference numerals. In FIG. 6, rotary heads H _A1 and H _A2 alternately scan a track in which the audio track and video track shown in FIG. 5 are recorded in an overlapping manner (hereinafter referred to as an overlapping recording track for convenience of explanation). Here, as mentioned above, the audio track is recorded by the rotary head H _A1 (or H _A2 ) with an azimuth angle of -30° (or +30°), and the video track is recorded superimposed on this audio track. is, for example, a track recorded by the rotating head H ₂ (or H ₁ ) with an azimuth angle of +6° (or -6°), so if the rotating head H _A1 scans the above-mentioned overlapping recording track, it will be affected by the azimuth loss effect. When only the first or third FM audio signal is reproduced and the rotary head H _A2 scans the next overlapping recording track, the second or fourth FM audio signal is reproduced.
FM audio signal is played.

Further, adjacent overlapping recording tracks on the magnetic tape 3 are tracks recorded by rotating heads with different azimuth angles, but the rotating heads H _A1 ,
When H _A2 scans overlapping recording tracks, the FM audio signal occupies a relatively low frequency band, as described above, and is mixed into the reproduced FM audio signal as crosstalk from adjacent tracks, albeit slightly. However, this crosstalk component can be completely removed by band filters 25 to 28, which will be described later.

In this way, the first to fourth FM audio signals reproduced from the overlapping recording tracks scanned by the rotary heads H _A1 and H _A2 are transmitted to the rotary transformer 1.
3 and 14 and preamplifiers 23 and 24, respectively, and are supplied to bandpass filters 25, 26, 27 and 28, respectively. Bandwidth filters 25, 26, 27 and 28
The center frequencies of the respective pass frequency bands are f ₁ , f ₃ ,
Since f ₄ and f ₂ are selected respectively, the first, second, third and fourth reproduced FM audio signals are frequency-selected and extracted and supplied to FM demodulators 29, 30, 31 and 32.

From this, FM demodulators 29, 30, 31 and 3
2, the reproduced audio signal is sequentially taken out for each track scanning period and supplied to the switching circuit 33, where it is processed by pulses synchronized with the rotation phase of the rotary heads H _A1 and H _A2 generated by known means. The signals are switched every one track scanning period and output as a continuous reproduced audio signal to the output terminal 34.

On the other hand, when reproducing the overlapping recorded tracks of the rotary heads H _A1 and H _A2 , the rotary heads H ₁ and H ₂ are regenerated after a slight fixed time delay corresponding to the rotation period of the head mounting angle difference θ shown in FIG. A rotating head having the same azimuth angle as the rotating head alternately scans overlapping recording tracks on which video tracks are recorded. For example, if the rotary head H _A1 is the overlapping recording track shown in FIG.
After the above-mentioned fixed time has elapsed since the start of scanning _t3 , rotary head _H1 starts scanning overlapping recording track _t2 shown in the figure, and after one track scanning period, rotary head _HA2 starts scanning overlapping recording track t2. After a certain period of time after starting scanning _t4 , rotary head _H2 starts scanning overlapping recording track _t3 .

As a result, the reproduction signal of the video track reproduced by the rotary head _H1 passes through the rotary transformer 18, the preamplifier 38, and the switching circuit 40 shown in FIG. are supplied respectively. The luminance signal reproducing thread 41 separates the reproduced FM luminance signal, then FM demodulates it to obtain a reproduced luminance signal of the original band, and outputs this to the mixing circuit 43. Further, the carrier color signal reproducing thread 42 separates the reproduced low frequency converted carrier color signal and returns it to the original band, and
A comb filter is used to remove the low frequency converted carrier color signal reproduced as crosstalk from the adjacent overlapping recording tracks, and only the reproduced carrier color signal of the scanning track is extracted and outputted to the mixing circuit 43. The mixing circuit 43 mixes both of the above signals and outputs it to the output terminal 44 as a reproduction standard color video signal.

When the above-mentioned scanning of each track by the rotary heads H _A1 and _H1 is completed, the switching circuits 35 and 40 are then switched and connected, and the overlapping recording track begins to be scanned by the rotary head _H2 . As a result, the rotary head _H2 is able to track the previously recorded FM of the audio track in the overlapping recording track due to the azimuth loss effect described above.
Almost no audio signals are reproduced, and previously recorded signals of the video track are reproduced. That is, the rotary head _H2 reproduces and outputs a frequency division multiplexed signal consisting of the low frequency conversion carrier chrominance signal and the FM luminance signal recorded on the overlapping recording track, and in this reproduced signal, there is no crosstalk from the adjacent track. A slight amount of the reproduced FM audio signal is mixed in. This reproduced frequency division multiplexed signal is transmitted to a rotary transformer 19,
A luminance signal regeneration thread 41 and a conveyed color signal regeneration thread 4 are passed through a preamplifier 39 and a switching circuit 40, respectively.
2, respectively. Since the luminance signal regeneration thread 41 and the conveyed color signal regeneration thread 42 perform the same operations as described above, the output from the mixing circuit 43 to the output terminal 44 is as follows.
The video signal for one field recorded on the overlapping recording track is output as a reproduction standard color video signal. In this way, according to this embodiment, the rotary heads H ₂ having mutually different azimuth angles
Since the overlapping recording tracks formed by overlapping recording by H _A1 and H _A1 or H A1 and H _A2 are sequentially reproduced by rotating heads at respective azimuth angles, the same rotating head can reproduce the FM audio signal and the low frequency conversion carrier color. Mutual interference due to beats between the FM audio signal, the low frequency conversion carrier color signal, and the FM brightness signal, which occurs when the signal and the FM brightness signal are simultaneously recorded and played back, hardly occurs. Therefore, color video signals and audio signals can be reproduced with high quality.

Next, rotary heads H _A1 and H _A2 for recording and reproducing audio signals
The tracking control operation will be explained below. 6th
In the audio signal reproduction string shown in the figure, the changeover switches 49 and 50 are configured to be switched in conjunction with the reproduction tracks of the rotary heads H _A1 and H _A2 .
The rotary heads H _A1 and H _A2 are connected to the fixed terminals 49a and 50a, respectively, during the period of replaying the overlapping recording tracks on which the first and fourth FM audio signals are recorded;
During the period of reproducing the duplicate recording track in which the second and third FM audio signals are recorded, the fixed terminal 49
b and 50b, respectively. As a result,
The differential amplifier 51 is connected to the common terminal of the changeover switch 49.
The detection signal of the FM audio signal reproduced as crosstalk is always supplied to the non-inverting input terminal of the rotary heads H _A1 and H _A2 from the track on the upstream side of the tape among the tracks on both sides of the track to be reproduced.
Moreover, the rotary heads H _A1 and H _A2 are connected to the inverting input terminal of the differential amplifier 52 from the common terminal of the changeover switch 50.
FM played as crosstalk from a track downstream of the tape adjacent to the track to be played.
A detection signal of the audio signal will be supplied. Note that the switching circuit 53 connects the rotary head H _A1 ,
Switching control is performed, for example, by a drum pulse, so that H _A2 blocks the transmission of the FM audio signal reproduced from the track to be reproduced, and transmits only the FM audio signal reproduced as crosstalk.

Now, suppose that the rotary head H _A1 is in one track scanning period during which the track t5 in FIG. ₅ in which the first FM audio signal (carrier frequency f ₁ ) is recorded is to be reproduced. The second track recorded on the adjacent track _t6 on the upstream side of tape ₅
FM audio signal (carrier frequency f ₃ ) and the fourth FM recorded on the adjacent track t ₄ on the downstream side of the tape.
The audio signal (carrier frequency f ₂ ) and track t ₅
It is reproduced as crosstalk and mixed into the reproduced FM audio signal. Playing the track to be played ₅
The frequency of the FM audio signal is selected by the band filter 25 and supplied to the FM demodulator 29, while its transmission is blocked by the switching circuit 53.
On the other hand, the second FM audio signal reproduced as crosstalk from the adjacent track _t6 is passed through the band filter 2.
After the frequency is selected by 6, it is supplied to the FM demodulator 30, and then passed through the switching circuit 53 and the level detection circuit 46, respectively, and converted into a DC voltage according to the reproduced FM level.
The signal is applied to the non-inverting input terminal of the differential amplifier 51 through the changeover switch 49 connected to the switch 49 .

Also, the fourth FM audio signal reproduced as crosstalk from the adjacent track _t4 is passed through the band filter 2.
After the frequency is selected by 8, it is supplied to the FM demodulator 32, and is converted to a DC voltage according to the reproduced FM level through a switching circuit 53 and a level detection circuit 48, and then is applied to a fixed terminal 50a.
The signal is applied to the inverting input terminal of the differential amplifier 51 through the changeover switch 50 connected to the differential amplifier 51.

Assuming that the rotary head H _A1 shifts to the track _t6 side during this one track scanning period, in this case, the crosstalk reproduced FM audio signal level of track _t6 is higher than that of the crosstalk of track _t4 . Compared to the talk playback FM audio signal level, it becomes relatively high depending on the amount of track deviation. Therefore, the output terminal 52 of the differential amplifier 51 becomes higher in accordance with the amount of track deviation than during normal reproduction without track deviation. Conversely, if the rotary head H _A1 moves toward track _t4 , the level of the crosstalk reproduced FM audio signal on track _t4 will be higher than the level of the crosstalk reproduced FM audio signal on track _t6 . Since it becomes relatively high depending on the amount, output terminal 5
2, a lower voltage corresponding to the amount of track deviation is obtained compared to when there is no track deviation.

The rotary head H _A2 then reproduces the overlapping recording track _t6 in which the second FM audio signal is recorded. During this one-track scanning period, the transmission of the second FM audio signal reproduced from the overlapping recording track _t6 is blocked by the switching circuit 53, and the _second FM audio signal is
The first and third FM audio signals reproduced as crosstalk from the overlapping recording tracks t ₅ and t ₇ adjacent to each other on both sides are supplied to the band filters 25 and 27, the switching circuit 53, and the level detection circuits 45 and 47. Ru. Since the changeover switches 49 and 50 are connected to the fixed terminals 49b and 50b during this one-track scanning period, the DC current corresponding to the crosstalk reproduced FM audio signal level from t5 taken out from the level detection circuit ₄₅ is switched to the fixed terminals 49b and 50b. The voltage is applied to the inverting input terminal of the differential amplifier 51 through the changeover switch 50,
On the other hand, the DC voltage corresponding to the level of the crosstalk reproduced FM audio signal from t ₇ extracted from the level detection circuit 47 is applied to the non-inverting input terminal of the differential amplifier 51 through the changeover switch 49 .

Therefore, the rotary head H _A2 has a duplicate recording track t ₆
If the rotary head H _A2 deviates to the upstream side of the tape and moves toward the overlapping recording track _t7 during one track scanning period in which the tape is to be reproduced, the adjacent track
Since the crosstalk level of the third FM audio signal at t ₇ becomes relatively higher than the crosstalk level of the first FM audio signal at the adjacent track t ₅ depending on the amount of track deviation, the differential The output voltage of the amplifier 51 becomes higher in accordance with the amount of track shift than when there is no track shift. On the other hand, the rotating head H _A2
If the tape runs with a deviation toward the overlapping recording track _t5 on the downstream side of the tape, as can be easily inferred from the above explanation, the output voltage of the differential amplifier 51 will change to the amount of track deviation compared to when there is no track deviation. It will be lower accordingly. Thereafter, the same operation as above is repeated.

In this way, the switching circuit 53 switches and outputs the FM audio signal that is reproduced as crosstalk from the adjacent tracks on both sides of the overlapping recording track to be reproduced, and the rotary heads H _A1 and H _A2
In the figure, when the tape is being played back with a track shift on the upstream side, the value will be high according to the amount of track shift, and on the other hand, when the tape is being played back with a track shift on the downstream side, the value will be low depending on the amount of track shift. A voltage corresponding to this value is taken out from the differential amplifier 51, and this voltage is applied as a track deviation detection voltage from an output terminal 52 to a known head moving mechanism (not shown). This head moving mechanism displaces the rotary heads H _A1 and H _A2 in the track width direction in a direction and displacement amount that minimizes the track displacement of the rotary heads H _A1 and H _A2 in accordance with the value of the track deviation detection voltage. This allows the rotating head to
H _A1 and H _A2 can be accurately scanned over the overlapping recorded tracks to be reproduced by tracking control that minimizes track deviation.

Next, the tracking control operation of the rotary heads H ₁ and H ₂ for recording and reproducing video signals will be explained. In FIG. 7, the reproduced frequency division multiplexed signal taken out from the switching circuit 40 is passed through a band filter 54,
55, 56 and 57, respectively, and reproduced here as crosstalk from adjacent tracks.
Switching circuit 5 after the audio signal is separated
8. Band filter 54, 55, 56
and 57 are configured to be able to separate the first, second, third and fourth FM audio signals of carrier frequencies f ₁ , f ₃ , f ₄ and f ₂ , respectively. The switching circuit 58 is switched and controlled in response to rotation detection pulses synchronized with the rotational phases of the rotary heads _H1 and _H2 , which are generated by known means.
H ₁ and H ₂ select and output only the two types of FM audio signals reproduced as crosstalk from the overlapping recording tracks on both sides of the overlapping recording track to be reproduced.

Two types of crosstalk reproduction FM audio signal level detection circuit 5 taken out from the switching circuit 58
After being supplied to the corresponding two level detection circuits 9 to 62 and converted there into DC voltages according to their envelope levels, one is supplied to the fixed terminal 63a or 63b of the changeover switch 63, and the other is supplied to the fixed terminal 63a or 63b of the changeover switch 63. It is supplied to the fixed terminal 64a or 64b of the changeover switch 64. The changeover switches 63 and 64 are alternately switched and connected in conjunction with each track scanning period of the rotary heads H ₁ and H ₂ by rotation detection pulses synchronized with the rotational phases of the rotary heads H ₁ and H ₂ , respectively. Specifically, the rotary heads H ₁ and H ₂ are connected to the fixed terminals 63a and 64a, respectively, during the period when the overlapping recording tracks on which the first and fourth FM audio signals are recorded, are connected to the second and fourth FM audio signals. During the period of reproducing the overlapping recording track in which the FM audio signals of No. 3 are recorded, they are switched and connected to the fixed terminals 63b and 64b, respectively. As a result, the rotary head can be connected to the common terminal of the changeover switch 63.
A DC voltage corresponding to the level of the FM audio signal reproduced as crosstalk is extracted from the adjacent track located upstream of the tape with respect to the overlapping recording track to be reproduced by H ₁ or H ₂ and is applied to the non-inverting differential amplifier 65. On the other hand, from the common terminal of the selector switch 64, the signal is reproduced as crosstalk from the adjacent track located downstream of the tape.
A DC voltage corresponding to the FM audio signal level is taken out and supplied to the inverting input terminal of the differential amplifier 65.

As a result, similar to the tracking control operation of the rotary heads H _A1 and H _A2 described above, the rotary head H ₁
Or, when _H2 is being played back with a track shift on the upstream side of the tape in FIG. On the other hand, when the tape is being reproduced with a track shift on the downstream side, a lower voltage corresponding to the amount of track shift is extracted from the differential amplifier 65 than when there is no track shift. The output voltage of the differential amplifier 65 is applied to a head moving mechanism (not shown) that displaces the rotary heads H ₁ and _{H 2 in} the track width direction using the track deviation as _a detection voltage. This is driven and controlled so that the deviation is minimized.

As described above, according to this embodiment, the carrier frequency of the FM audio signal is switched and recorded for each track, and two types of FM audio signal levels are reproduced as crosstalk from adjacent tracks on both sides of the track to be reproduced. By comparing the levels, track deviation information of the rotating heads H _A1 , H _A2 , H ₁ , H ₂ is obtained, and the head moving mechanism is driven based on this, so the pilot signal for tracking control is The rotary head can be used without recording or reproducing data or without rocking the rotary head.
Tracking control of H _A1 , H _A2 , H ₁ , and H ₂ is possible.

Incidentally, in the above explanation, the recorded and reproduced audio signal was explained as being of a single channel, but the second, third and fourth embodiments in the case of two channels will be explained next.

The second embodiment of the present invention supplies the left (or right) channel audio signal to the input terminal 5 shown in FIG. 3, and supplies the right (or left) channel audio signal to the input terminal 6. , an audio signal recording circuit 67 and a mixing circuit 68 shown in broken lines in FIG. 3 are provided in the recording system, respectively, and an FM audio signal reproducing circuit 69 shown in broken lines in FIG.
The rest is the same as the first embodiment. As shown in FIG. 8, the audio signal recording circuit 67 receives the audio signal of one of the two channels from the input terminal 6 at a frequency.
It is composed of a frequency modulator 71 that frequency modulates a carrier wave of f ₅ (for example, 2.1 MHz), and supplies the fifth FM audio signal extracted from this to a mixing circuit 68, where it is connected to the other signal from the switching circuit 12. Frequency division multiplexing is performed on the FM audio signals of - of the first to fourth channels. As a result, the fifth FM audio signal of one channel is continuously recorded on all audio tracks at the same carrier frequency _f5 , and the FM audio signal of the other channel has its carrier frequency f5 as described above. The signals are cyclically switched in the order of f ₁ →f ₃ →f ₄ →f ₂ →f ₁ →... every one track scanning period and recorded on the audio track.

In addition, in the case of the regenerated yarn, the FM audio signal reproducing circuit 69 shown in FIG. The configuration is such that the fifth FM audio signal is discriminated and separated from the reproduced FM signal taken out from the circuit 35 and then supplied to the FM demodulator 73.
As a result, the demodulated audio signal of one channel is continuously extracted from the FM demodulator 73, and the demodulated audio signal of the sixth channel is continuously extracted.
It is output to the output terminal 70 shown in the figure. Further, the audio signal of the other channel is continuously taken out from the output terminal 34 shown in FIG. 6 in the same manner as in the first embodiment. Furthermore, the track deviation information is stored in the first to fourth
It is obtained from the FM audio signal level in the same manner as in the first embodiment.

Next, a third embodiment of the device of the present invention will be described. In this embodiment, the audio signal recording circuit 67 shown in FIG. 3 is configured as shown in FIG. 10, and the audio signal recording circuit 67 shown in FIG.
This embodiment differs from the second embodiment in that the FM audio signal reproducing circuit 69 has the configuration shown in FIG. In FIG. 10, the audio signal of one channel entering the input terminal 6 is transmitted to the frequency modulators 74, 75, 76 and 7.
7, where the frequency f ₅ (e.g. 2.1M
Hz), _f7 (eg 2.6MHz), _f8 (eg 2.85MHz) and _f6 (eg 2.35MHz). The fifth to eighth FM audio signals taken out from the frequency modulators 74 to 77 are supplied to a switching circuit 78. The switching circuit 78 is configured to be switched and controlled in conjunction with the switching circuit 12 shown in FIG. 3, and the carrier wave frequency changes f ₅ →f ₇ →f ₈ →f ₆ →f ₅ → every one track scanning period. The FM audio signals switched in this order are output and supplied to the combining circuit 68 in FIG. Carrier frequencies f ₅ , f ₇ , f ₈ above
The frequency spectra of the _5th , 6th, 7th and 8th FM audio signals of A 5 and f 6 are indicated by the broken lines A 5 and f ₆ in FIG.
The results will be as shown by A ₆ , A ₇ and A ₈ .

Thereafter, recording is performed in the same manner as in the first embodiment. As a result, in the tape pattern shown in FIG. 5, for example, the _first and fifth FM audio signals are frequency-division multiplexed and recorded on track t1, and the second and sixth FM audio signals are recorded on track _t2 . The signals are recorded by frequency division multiplexing the third and seventh FM audio signals on track _t3 , and the fourth and eighth FM audio signals on track _t4 , respectively. A similar combination results in a track pattern in which two FM audio signals are recorded on successive tracks.

On the other hand, the recycled yarn of this third embodiment is shown in Figure 6.
The FM audio signal reproducing circuit 69 has a configuration as shown in FIG. In FIG. 11, the reproduced FM taken out from the switching circuit 35 in FIG.
After the audio signals are separated from the fifth to eighth reproduced FM audio signals by band filters 79 to 82, they are supplied to FM demodulation circuits 83 to 86, where they are
After being FM demodulated, the signal is supplied to the switching circuit 87. Since the switching circuit 87 is configured to switch in conjunction with the switching circuit 33, the switching circuit 87 continuously outputs the reproduced audio signal of one channel to the output terminal 70. Also, at this time, the reproduced audio signal of the other channel is continuously output to the output terminal 64 in FIG.

In the third embodiment, the track deviation information can be obtained by combining the crosstalk reproduction levels of the FM audio signals of the two left and right channels, or by combining the crosstalk reproduction levels of the FM audio signals of the two left and right channels, or by combining the crosstalk reproduction levels of the FM audio signals of the two left and right channels, or by combining the It can also be obtained from the crossstroke playback level of the channel's FM audio signal.

Next, a fourth embodiment of the apparatus of the present invention will be described. FIG. 12 shows an example of a tape pattern by the recording system of this embodiment. In the figure, the same components as those in FIG. 5 are denoted by the same reference numerals, and the explanation thereof will be omitted.
In Fig. 12, the FM audio signal of one of the two channels is compressed by approximately twice the time axis in the lower half of each overlapping recording track (shown with diagonal lines at sparse intervals). In addition, in the upper half (shown with closely spaced diagonal lines), the FM audio signal of the other channel is recorded with the time axis compressed approximately twice. Also,
The carrier wave frequency of the FM audio signals of the two left and right channels changes every track scanning period.
For example, they are cyclically switched and recorded in the order of f ₁ →f ₃ →f ₄ →f ₂ →f ₁ →... Therefore, according to this embodiment, there are four types of carrier frequencies f ₁ to _{f 4} for the FM audio signals of the two channels, and the second
Similarly to the third embodiment, a rotary head H ₁ , which is based on high-quality recording and playback of two-channel stereo audio signals and the crosstalk playback level of FM audio signals.
Tracking control of H ₂ , H _A1 , and H _A2 is possible.

Application Examples The present invention is not limited to the above-mentioned embodiments, and various other application examples are possible.
First, the tracking control operation of the rotary heads H ₁ , H ₂ , H _A1 , and H _A2 can also be performed during recording.
In this case, when the rotary heads H _A1 and H _A2 are recording an audio track or the rotary heads H ₁ and H ₂ are recording a video track, a predetermined extremely small the rotating head for a period of
H _A1 , H _A2 , H ₁ or H ₂ is operated as a playback head to play back the previously recorded FM audio signal of the adjacent audio track as crosstalk,
Thereafter, switching the rotary head H _A1 , H _A2 , H ₁ , or H ₂ to operate as a recording head again is repeated each time each track is recorded, and two adjacent
The track shift detection voltage is extracted by comparing the FM audio signal levels sequentially reproduced as crosstalk from the book track every track scanning period.
From its level and polarity, the rotating heads H _A1 , H _A2 ,
The drive of the head moving mechanism is controlled so that the track deviation of H ₁ or H ₂ is minimized.

Also, rotary heads H _A1 and H _A2 for recording and reproducing audio signals.
is for other purposes (for example, special playback, erasing, etc.)
It is also possible to use a rotary head that can also be used.

Further, a first head moving mechanism for displacing the rotary heads H ₁ and H ₂ in the track width direction and a second head moving mechanism for displacing the rotary heads H _A1 and H _A2 in the track width direction are provided, respectively. However, it is also possible to provide a pair of rotating heads H ₁ , H ₂ and rotating heads H _A1 , H _A2 in one head moving mechanism, in which case the tracking of the above-mentioned rotating heads H _A1 , H _A2 is possible. Either one of the servo circuit and the tracking servo circuit for the rotating heads H ₁ and H ₂ may be omitted.

Furthermore, each of the above embodiments includes a pair of rotating heads.
Although the azimuth angles of H _A1 and H _A2 are different, +30° and -30°, the azimuth angles can be made the same for ease of detecting track deviation, accuracy, etc. In this case, crosstalk from adjacent tracks of the FM audio signal can be removed by a normal bandpass filter. Furthermore, the rotating head H ₁ ,
Of course, H ₂ , H _A1 , and H _A2 may be attached to a rotating body such as a disk plate sandwiched between upper and lower fixed drums.

Effects As described above, according to the present invention, the carrier wave frequency of the FM audio signal recorded on the audio track is sequentially and cyclically switched to any one of four types of carrier wave frequencies for each track scanning period. Therefore, the FM audio signals reproduced as crosstalk from audio tracks adjacent to both sides or one side of the track to be scanned are discriminated and separated by a filter circuit, and track deviation information is detected based on the crosstalk level. Therefore, even if a pilot signal is not specially recorded or the rotary head is not oscillated, at least the rotary head for recording and reproducing video signals can be recorded at a constant track pitch both during recording and reproducing. During playback, tracking control can be performed to accurately scan the recording track, and since it is possible to select the frequency of only the audio signal from the audio track being scanned, crosstalk components from adjacent tracks can be controlled. This makes it possible to record and reproduce audio signals with high quality, and from the above, it is particularly applicable to magnetic recording devices or magnetic recording and reproducing devices in which the relative linear velocity between the tape and the head is slowed down. It has many features such as being suitable.

[Brief explanation of drawings]

1 and 2 are a plan view and a side view, respectively, showing one embodiment of the head arrangement in the apparatus of the present invention, and FIG. 3 is a block system diagram showing each embodiment of the recording system of the apparatus of the present invention. 4 shows examples of frequency spectra of signals recorded and reproduced by the apparatus of the present invention, FIG. 5 shows an example of tape patterns recorded and reproduced by the present invention, and FIGS. 6 and 7.
The figure is a block system diagram showing each main part of each embodiment of the recycled yarn of the apparatus of the present invention, and FIGS. 8 and 10 are block systems showing each embodiment of the main part in the block system shown in FIG. 3, respectively. 9 and 11 are block system diagrams showing respective embodiments of the main parts in the block system shown in FIG. 6, and FIG. 12 shows another example of the tape pattern recorded and reproduced according to the present invention. FIG. DESCRIPTION OF SYMBOLS 1... Rotating drum, 3... Magnetic tape, 5, 6... Audio signal input terminal, 7... Standard color video signal input terminal, 8-11, 71, 74-77... Frequency modulator, 15... Luminance signal recording system, 16...Conveyance color signal recording system, 25-28, 54-57, 72, 79-
82...Band filter, 29-32, 73, 83-
86...FM demodulator, 34...Playback audio signal output terminal, 41...Luminance signal playback thread, 42...Carrier color signal playback thread, 51, 65...Differential amplifier, 52...Head
Track deviation detection voltage output terminal for H _A1 and H _A2 , 6
6... Track deviation detection voltage output terminal of heads _H1 , _H2 , 67... Audio signal recording circuit, 69... FM audio signal reproducing circuit, 70... Reproducing audio signal output terminal,
H _A1 , H _A2 ...Rotary head for recording and reproducing audio signals,
H ₁ , H ₂ ...Rotating head for recording and reproducing video signals.

Claims (1)

[Claims] 1. A rotating body on which a magnetic recording medium is attached and wound over a certain angle range has a plurality of rotating heads for recording and reproducing video signals having mutually different azimuth angles, and the rotary heads for recording and reproducing video signals have azimuth angles that are different from each other. A magnetic recording and reproducing apparatus is provided with a plurality of different rotary heads for recording and reproducing audio signals, in which the carrier wave frequency is set to one of four types for each track scanning period of the rotary head for recording and reproducing audio signals. means for generating and serially outputting a frequency modulated audio signal whose carrier frequency is sequentially and cyclically switched to a carrier wave frequency; and an audio track on which the frequency modulated audio signal is recorded on the traveling magnetic recording medium. a first recording means for forming a recording without or with a very small guard band by a rotary head for recording and reproducing; and a video signal is recorded on the already recorded audio track of the magnetic recording medium by the rotary head for recording and reproducing video signals. a second recording means for recording and forming video tracks in an overlapping manner; and a second recording means for recording and forming video tracks in an overlapping manner; filter circuit means for frequency-selecting and outputting only the reproduced frequency-modulated audio signals from the audio tracks adjacent to both sides or one side of the video track; means for obtaining track deviation information of the video signal recording and reproducing rotary head with respect to the video track to be reproduced based on the level; 1. A magnetic recording/reproducing device comprising a head moving mechanism for displacing the head in the track width direction so that the head is moved in the track width direction.