JPS61265990A - Magnetic recording method - Google Patents

Abstract

PURPOSE:To form a high quality reproduced color video signal where a crosstalk is inconspicuous by recording a luminance signal and a chrominance signal on different tracks and recording the same type of signals with line- correlation on adjacent tracks. CONSTITUTION:An FM luminance signal and a frequency division multiplex signal from switch circuits 27 and 28 are alternately switched and outputted by every 1H, supplied to the 1st and 2nd rotating heads 52 and 53 through recording amplifiers 50 and 51, and simultaneously recorded on a magnetic tape 54 or recorded individually by forming two tracks. The same type of signals, however different by one horizontal period, are recorded on two adjacent tracks during a horizontal scan period. The crosstalk from the adjacent tracks is negligible due to a guard band between two tracks simultaneously formed and the phase matching of FM signals recorded on two tracks.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic recording method, and more particularly to a magnetic recording method in which luminance signals and color signals are recorded on separate tracks using separate rotary heads on a magnetic tape.

2. Description of the Related Art Currently, helical scan type magnetic recording and reproducing devices (VTRs) using 172-inch wide magnetic tapes have relatively narrow recording and reproducing bands for home use, so they cannot record or reproduce luminance signals separated from color video signals. Among the carrier color signals, the luminance signal is frequency-modulated to become a frequency-modulated wave, and the carrier color signal is converted to a low-frequency carrier color signal, and then the frequency-modulated wave 1171i is
The system uses a so-called low frequency conversion color recording and reproducing method, in which frequency division multiplexing is performed on a single signal, and this frequency division multiplexed signal is recorded on a magnetic tape and reproduced. It uses a guard panless recording method in which the azimuth angle of each rotating head for recording tracks is different. On the other hand, commercial VTRs intended for broadcasting, especially VTRs with built-in cameras, have the same tape width as home VTRs in order to make the device smaller and lighter and to improve the quality of reproduced color video signals. A method is used in which luminance signals and color signals are recorded on separate tracks using separate rotating heads on magnetic tape, and a guard band is provided between adjacent tracks to record and play back the signals. .

FIGS. 11 and 12 respectively show track patterns recorded and formed by the above-mentioned conventional camera-integrated VTR. In FIG. 11, tracks 21, 22, and 23, which are inclined with respect to the longitudinal direction of the magnetic tape 1, are tracks on which frequency-modulated luminance signals (hereinafter referred to as FM''i degree signals) are recorded, and tracks 3+, 32.3s are color difference signals ■.

This is a track on which first and second frequency-modulated color difference signals (hereinafter referred to as FM color difference signals) obtained by separately frequency modulating different carrier waves with Q are frequency-division multiplexed and recorded. Tracks 21 and 31 are tracks on which the FM luminance signal and FM color difference signal of the same field are recorded simultaneously and separately.
are tracks on which the FMii degree signal and the FM color difference signal of the same field are recorded simultaneously and separately.

Furthermore, the plurality of rotating heads that record and form tracks 21 to 2g and 3+ to 33 all have the same azimuth angle,
A guard band (no signal recording band) is formed between adjacent tracks. In FIG. 11, 41 and 42 are audio tracks on which the audio signals of the first and second channels are recorded, and 5 is an audio track where the audio signals of the first and second channels are recorded. A control track 6 is formed by a control head, and a time code track 6 is formed by a time code head.

On the other hand, on the magnetic tape 7 shown in FIG. 12, there are inclined tracks 8+, 82.9+, 92 and first . Audio tracks 10+ and 102 of the second channel, a time code track 11, and a control track 12 are recorded, respectively. Recording tracks 81 and 82 are tracks on which FM luminance signals are recorded by a rotating head with an azimuth angle of -15°, and recording tracks 91 and 92 are tracks on which FM time-base compressed color difference signals are recorded with a rotating head with an azimuth angle of +15°. It is. Here, the FM time axis compressed color difference signal is the color difference signal (R-Y) and (B-Y
) is compressed to 172 times, and then time-division multiplexed alternately every H/2 (where H is the horizontal scanning period), and this time-division multiplexed signal is used to frequency modulate the carrier wave. . After recording and forming tracks 8I and 91 simultaneously and separately using the two first rotary heads with an azimuth angle of -15° and the two second rotary heads with an azimuth angle of +15°, , track 82 in the next field
and 92 are recorded and formed simultaneously and separately, and thereafter, two tracks are recorded and formed in the same manner. Further tracks 8+, 82.9+.

A guard band is formed between 62 adjacent tracks among the 92 tracks to avoid mutual crosstalk.

In the color video signal recording and reproducing apparatus that forms either of the track patterns shown in FIGS. 11 and 12 above,
Since the luminance signal and the color difference signal are recorded on separate tracks and reproduced, the FM luminance signal and the low frequency conversion carrier color signal are simultaneously transmitted using the nonlinear transmission system in the VTR using the low frequency conversion color recording and reproducing method described above. Moiré, which occurs when recording and reproducing on the same track on a magnetic tape, does not occur, and the image recording and reproducing bands for the luminance signal and color difference signal can be made sufficiently wide, and the low-frequency conversion carrier color signal can be converted to FM. Since bias recording is not performed using a luminance signal, the S/N (signal-to-noise ratio) of the reproduced color difference signal can be improved, and as described above, the reproduced color video signal can be reproduced with higher image quality than a VTR using the low-frequency conversion color recording and reproduction method. Obtainable.

Problems to be Solved by the Invention However, the above-mentioned conventional color video signal recording and reproducing apparatus has the following problems:
Since both have a guard band, the efficiency of magnetic tape usage is poor, and if the rotating head crosses the guard band and scans adjacent tracks during playback, two adjacent tracks will have an FM Since the luminance signal and the FM color difference signal are recorded separately, the luminance signal rotary head (or the color difference signal rotary head) records the FM color difference signal (or the FM color difference signal).
Since there is no field correlation between the reproduced signals of both tracks, it is necessary to reproduce the field correlation, as is done in the home VTR that uses the above-mentioned low frequency conversion color recording and reproduction method. There was also the problem that the crosstalk cancellation method used could not be used, resulting in reproduced images with noticeable crosstalk.

Further, the conventional color video signal recording and reproducing apparatus described above differs from the recording pattern of the VTR (hereinafter referred to as home VTR) using the low frequency conversion color recording and reproducing method and the guard panless recording and reproducing method. 1 field of FM luminance signal recording track (for example, 21 or 81)
and the next 1 field of FMII degree signal recording track (2
2 or 82) are tracks recorded with a rotary head having the same azimuth angle, so it was not possible to reproduce the video signal of the magnetic tape recorded on the home VTR. In addition, in order to ensure compatible playback at least regarding the luminance signal, the azimuth angle of the two rotary heads for recording the FMH degree signal of the two tracks formed for each field is adjusted to the same angle as that of the current home VTR. The two rotary heads are the same, for example +6° and -6°, and the azimuth angles of the two rotary heads for color signal recording are different from the other rotary heads (for example, +30° and -30°). , it is conceivable to make the track pitch of each two tracks the same as that of a home VTR.

However, in this case, two adjacent tracks are simultaneously
In addition, if two rotating heads that scan separately cause tracking deviation in the same direction during reproduction, the two adjacent tracks are recorded and formed by rotating heads with different azimuth angles. A large time difference occurs between the reproduced luminance signal and the reproduced chrominance signal that are reproduced separately from the two tracks, making it difficult to time-align the raw signals of both pages. The same applies to playback devices). Furthermore, in this case, all four adjacent tracks are tracks recorded by rotating heads with different azimuth angles, so during variable speed playback where two or more recording tracks are scanned in one field scanning period, one The rotary head has only one reproducible track out of every four, and a complicated mechanism and its llltl are required to control the height position of the rotary head using an electro-mechanical transducer.
Variable speed reproduction is difficult without the II circuit.

Therefore, the present invention uses at least a luminance signal and a color signal (however, the color signal in the water version is a color difference signal).

It is assumed that the signal includes all carrier color signals, three primary color signals, etc. ) are switched alternately every horizontal scanning period (1 day), and two records are formed simultaneously and separately.
It is an object of the present invention to provide a magnetic recording method that solves the above-mentioned problems by recording H signals of the same type, one measurement each other, on the tracks of a book.

Means for Solving the Problems The magnetic recording method according to the present invention records one frequency-modulated luminance signal and one frequency-modulated color signal on each of two tracks that are simultaneously and separately recorded. A signal is recorded by switching alternately every horizontal scanning period and multiplexing a pilot signal onto one of these two signals. Further, the horizontal synchronizing signal recording positions of each of these two tracks are recorded in alignment in the track width direction, and furthermore, the same type of signal is recorded in each of the adjacent horizontal scanning periods of the two tracks, which are different from each other by one horizontal scanning period. are recorded together.

In the two tracks mentioned above, which are recorded simultaneously and separately, horizontal synchronizing signals are recorded in alignment in the track width direction (so-called H-aligned recording), and in adjacent one-day periods, Signals of the same type (for example, a frequency modulated luminance signal or a frequency modulated color signal, and a pilot signal multiplexed with one of these signals) between the current horizontal scanning period and the horizontal scanning m 1H before are recorded. Ru. Therefore, in the 62 adjacent tracks, frequency modulated waves modulated by signals with line correlation are recorded side by side, so that the frequency modulated waves that are reproduced as crosstalk from the adjacent tracks during playback. The frequency of the modulated wave and the frequency of the reproduced modulated wave of the reproduced track are approximately the same frequency, and since the frequency of the beat caused by both signals is close to zero, there is almost no influence of crosstalk.

Furthermore, since the four adjacent tracks are tracks recorded with no or almost no guard band by a rotating head having one of two types of azimuth angles, during variable speed playback, only one track can be played by one rotating head. 2 out of 4, and variable speed playback is possible.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to examples shown in the drawings.

FIG. 1 shows a block diagram of an embodiment of the method of the invention. In the figure, a luminance signal Y is input to the input terminal 15, and color difference signals B-Y and RY are input to the input terminals 16 and 17.
An audio signal enters the input terminal 18. The luminance signal from the input terminal 15 is sent to an emphasis circuit 19 and an addition circuit 2.
0 to the frequency modulator 21, respectively. Also,
At the same time, the input luminance signal is transferred to the 18W extension circuit 22. The signal is supplied to a frequency converter 25 through an emphasis circuit 23 and a subtraction circuit 24. The frequency modulators 21 and 25 each modulate the frequency of the carrier wave with the input luminance signal, so that the carrier wave shift band is, for example, 6MH2 to 7MHz, as shown in FIG. 2(A).
In MH2, the lower sideband is a frequency modulated luminance signal (FM
Generates and outputs a luminance signal). The first FM luminance signal from the frequency modulator 21 is supplied to the phase detector 26, while
It is supplied to the terminal 27a of the switch circuit 27. Further, the second FM luminance signal delayed by 1H from the frequency modulator 25 is supplied to the phase detector 26, and is also supplied to the terminal 28a of the switch circuit 28.

The phase detector 26 is a circuit that generates and outputs an error voltage according to the phase difference between the first and second FM luminance signals, and the output error voltage (this is an extremely small value) is added to an adder circuit. 20 and subtraction circuit 21, respectively. As is well known, the frequency modulators 21 and 25 are a type of voltage-frequency converter, and the output voltage of the adder circuit 20 is increased by the error voltage.
Since the first F from the frequency modulator 21
The wavelength of the M luminance signal is shortened by that amount. On the other hand, since the output voltage of the subtraction circuit 24 decreases by the above error voltage, the wavelength of the second FM luminance signal from the frequency modulator 25 increases by that amount.

As a result, the feedback loop described above causes the first
The open signal phase difference of the second FM II degree signal is controlled in the direction of the pillow, and the phases of both FM luminance signals are made to substantially match. The first and second FMlEii degree signals are modulated waves obtained by frequency modulating a carrier wave with luminance signals having a time difference of 1H from each other, and since there is usually line correlation, the frequency of the modulated waves is They are substantially the same, and their phases are also substantially the same due to the feedback loop. This makes it possible to reduce the influence of crosstalk from adjacent tracks, as will be described later.

The switch circuits 27 and 28 selectively output the input signal of the terminal 278.28a during a certain 1H period by using switching pulses generated based on the horizontal synchronization signal obtained separately from the input luminance signal, and select and output the input signal of the terminal 278.28a during the next 1H period. Terminals 27b, 28
Select and output the input signal of b, and then output the terminal 2 during the next 1H period.
The input signals of 7a and 28a are selectively output.
Connections are switched alternately every day. The other terminals 27b and 28b of the switch circuits 27 and 28 receive frequency division multiplexed signals regarding color signals and pilot signals that have been subjected to signal processing as described below. The color difference signals B-Y and R-Y input to the input terminals 16 and 17 are sent to the emphasis circuit 3.
0.31, an adder circuit 32, and a subtracter circuit 33, and are supplied to frequency modulators 34 and 35. The frequency modulator 34 frequency-modulates the carrier wave with the input color difference signal B-Y, as shown in FIG.
In B), a first FM color difference signal having a frequency spectrum as shown by ■ is output. In FIG. 2(B), I[[c is the carrier wave shift band of the first FM color difference signal (for example, 1.5MH2±
250kHz). On the other hand, the frequency converter 35 frequency-modulates the carrier wave using the input color difference signal RY and outputs a second FM color difference signal occupying a low frequency band.

The above first and second FM color difference signals are passed through a low pass filter 36
．． After the unnecessary high frequency components are sufficiently attenuated by 37,
The voltage is supplied to the phase detector 38, where it is converted into an error voltage according to their phase difference, and then fed back to the addition circuit 32 and the subtraction circuit 33, respectively. As a result, as in the case of the FM luminance signal, the frequency modulators 34 and 35 output the first and second signals with a mutual phase difference of approximately zero. A second FM color difference signal is taken out, the first FM color difference signal is supplied to an adder circuit 39, and the second FM color difference signal is supplied to a frequency converter 45 and a one-day delay circuit 47, respectively.

On the other hand, the audio signal that has entered the input terminal 18 is supplied to the frequency modulator 41 through the emphasis circuit 40, where it is converted into an FM audio signal, and then unnecessary frequency components are sufficiently attenuated by the bandpass filter 42, and the adder circuit 39 supplied to. Here, for convenience of explanation, the audio signal has been explained as having one channel, but in reality it has two channels, and there are two systems of the above-mentioned emphasis circuit 401, frequency modulator 41, and bandpass filter 42, and the FM audio signals of two channels are added. It is supplied to circuit 39. The frequency spectrum of the two-channel FM audio signal is shown in FIG. 2(B) as V and VI, respectively. Note that the phases of the two-channel FM audio signals are also adjusted in the same manner as before. This FM audio signal also serves as a pilot signal, as will be described later. In this way, the frequency division multiplexed signal of the first FM color difference signal and the FM audio signal is taken out from the addition circuit 39, and the addition circuit 4
3, and is also supplied to an adder circuit 49 through a one-day delay circuit 44. The adder circuit 43 adds the first FM color difference signal and the FM audio signal from the adder circuit 39 to the first FM color difference signal and the FM audio signal, which are extracted from the frequency converter 45 and which are inputted into the first FM color difference signal and the FM audio signal from the frequency spectrum ■, whose carrier wave shift band is indicated by IVc in FIG. 2(B). The 3 FM color difference signals are frequency-division multiplexed, and thereby a frequency-division multiplexed signal with the frequency allocation shown in FIG. 3B is supplied to the terminal 27b of the switch circuit 27.

On the other hand, the second F delayed by one day by the one-day delay circuit 47
The M color difference signal is supplied to a frequency converter 48, where it is frequency-converted with the signal from the oscillator 46, and is shown in FIG. 2(B).
After being converted into a third FM color difference signal having a frequency spectrum as shown in , it is supplied to an adder circuit 49 . Here, the third FM color difference signal is not directly generated by the frequency modulator 35, but one frequency converter 45, 48 . Using the oscillator 46,
The low frequency second FM color difference signal is transferred to the desired high frequency third FM color difference signal.
It is the one-day delay circuit 47 that converts the FM color difference signal.
For example, when using a charge transfer device such as COD,
This is because the transmission band is limited to a low frequency band. Therefore, the second FM color difference signal of low frequency is supplied to the input terminal of the one-day delay circuit 47, where it is delayed for one day and then frequency-converted to a desired high frequency region. In this way, from the adder circuit 49, a frequency division multiplexed signal having the same frequency spectrum as shown in FIG. , is supplied to the terminal 28b of the switch circuit 28.

As described above, the switch circuits 27 and 28 are linked and alternately switched and connected each day. Therefore, the output FM luminance signal of the frequency modulator 21 is shown in FIG.
), the output frequency division multiplexed signal of the adder circuit 43 is shown in the same figure (
C) and the one-day delayed frequency division multiplexed signal output from the adder circuit 49 are schematically shown in 1H units in FIG.
Furthermore, the output signals of the switch circuit 28 are as schematically shown in FIG. However, Fig. 3 (A) - (
In F), the suffix y and the suffix C indicate scanning line numbers (the same applies to FIGS. 9(A) to 9(D), which will be described later). Therefore, Fig. 3 (
As can be seen from E) and (F), the FM luminance signal and the frequency division multiplexed signal are alternately switched and output from the switch circuits 27 and 28 every day, and there is a time difference of 1H between them during the same day. Signals of the same type having the following values are output. The output signals of the switch circuits 27 and 28 are sent to the recording amplifier 5.
0.51 to the first rotary head 52 and second rotary head 53, and are recorded simultaneously and separately forming two tracks on the magnetic tape 54.

As shown in FIG. 4, the rotating heads 52 and 53 are mounted in pairs on the rotating surface of a rotating drum 56, which is an example of a rotating body, facing each other.
2B constitutes a first rotating head 52, and a rotating head 53
A and 53B constitute the second rotating head 53. The rotating drum 56 rotates counterclockwise in FIG. 4, and the magnetic tape 54 is wound diagonally around the rotating drum 56 over an angular range of 180° plus the angle of overlap recording.
During normal recording and playback, the vehicle is caused to travel rightward in the figure. The rotating heads 52A and 52B are as shown in FIG.
The first and second parts are installed at the same height and are different from each other.
(This is the same as that of current home VTRs, for example, +6° and -6°), and similarly, the rotary heads 53A and 53B have a gap of azimuth angle of 1.
The rotary head 52A has a gap of a second azimuth angle.
, 52B at the same position higher by a certain value. Furthermore, adjacent rotary heads 52A and 53A, 52B and 53B have the same azimuth angle gap and are separated by a distance corresponding to a recording length of 28 (or other even number H) on the magnetic tape.

The rotating heads 52 (52A, 52B) and 5 with such a configuration
3 (53A, 53B), a track pattern as shown in FIG. 6 is formed. In the figure, magnetic tape 54
The rotating heads 52A and 53A are rotated during one field period.
Tracks TIA and TIB are recorded and formed separately and simultaneously by the rotary head 52 in the next one field period.
Tracks T2A and T28 are recorded simultaneously by 8.53B, and thereafter, the rotating head 52A is rotated every field period.
and 53A.

and 52B and 538 alternately track T3μ"3B
, T4A and TAB. Also, a slight guard band is formed between the two tracks TiA and Ti8 that are formed at the same time, and no guard band is formed between the track Ti8 and "(i+1)A." and the track “iA,”
The track width, which is the sum of both track widths of ``iB'', is selected to be equal to the track width of the recording track of the current home VTR, and the track inclination angle .theta. is also the same as that of the home VTR.

In addition, in Fig. 6, various signals recorded by the fixed head (for example, control pulses, audio signals, etc.)
The illustration of the track is omitted (the same applies to FIG. 10, which will be described later).

FIG. 7 is an enlarged view of the part surrounded by the broken line 58 in FIG. 6, showing that the horizontal periodic signal recording positions of tracks T4A and T4B are recorded aligned in the track width direction (so-called H-aligned recording). ). Although the conditions for the above H-aligned recording are already widely known, each parameter is selected so as to satisfy the following equation.

(V/F) CO3θ-M (N+ (1/2)) However, in the above formula, ■ is the tape running speed, F is the field frequency of the video signal to be recorded, and θ is the tape The track inclination angle of 9M on the format is track TI.
A ~ “4A, T1B ~” 1 horizontal scanning period at 4B (
1H) recording length, N is a positive integer. Such H-aligned recording is effective in reducing the influence of crosstalk from adjacent tracks.

Further, as can be seen from FIG. 7 and FIGS. 3(E) and (F), the same type of signals that differ by one horizontal scanning period from each other in adjacent horizontal scanning periods of the two tracks "4A and TAB" According to this embodiment, by such H alignment recording, the guard band between the two tracks formed at the same time, and the phase alignment of the FM signals recorded on the two tracks, In addition, magnetic tape recorded on a current home VTR can be reproduced by the device of this embodiment, in which case only one of the rotary heads 52 and 53 is used for reproduction.

Furthermore, only one of the rotary heads 52 and 53 is used, or the FM color difference signal with the same information content is transmitted to the rotary heads 52 and 5.
By simultaneously supplying the signal to both of 3, it is possible to record and form a track pattern that can be reproduced even on a home VTR.

Next, an apparatus for reproducing signals recorded on a magnetic tape recorded by the method of the present invention will be explained with reference to FIGS. 8 and 9.

In FIG. 8, the same components as in FIG. 1 are given the same reference numerals. Recording signals on a magnetic tape 54 having a track pattern as shown in FIG.
It is reproduced by simultaneously and separately scanning two tracks per field period. The first and second reproduced FM signals simultaneously and separately reproduced by the rotary heads 52, 53 are supplied to switch circuits 62, 63 through reproducing amplifiers 60, 61. The second regenerative FM signal from the regenerative amplifier 61 is shown in Fig. 2 (B) every 1H.
is the frequency division multiplexed signal shown in FIG.
After only the FM audio signal of one predetermined channel is separated into P waves, it is supplied to a level detector 65, where it is level detected (envelope detection), and then waveform-shaped by a waveform shaping circuit 66 for each field. It is assumed to be an inverted switching pulse. Here, the FMg voice signal is frequency division multiplexed and recorded together with the FM color difference signal, but is not multiplexed with the FM luminance signal. Therefore, the FM audio signal is 1
Since it is taken out every other day, it can be used as a pilot signal. Therefore, during one day when the FM audio signal @ (frequency division multiplexed signal) is taken out from the waveform shaping circuit 66, the level is high, and the reproduced FM l
It is possible to generate a switching pulse that is inverted every field and is at a low level during the next 1H period when the i-degree signal is extracted.

This switching pulse is supplied to switch circuits 62 and 63, which are alternately switched and controlled every day. During the day when the FMI signal is regenerated by the rotary heads 52 and 53, the terminals 62a and 63 of the switch circuit 62 and 63
A reproduced FM luminance signal is selectively outputted from a, and after being FM demodulated by an FM demodulator 67.68 in the next stage, it is supplied to a low-pass filter de-emphasis circuit 69.70. The first signal extracted from the low-pass filter de-emphasis circuit 69
The reproduced luminance signal is 1 compared to the second reproduced luminance signal taken out from the low-pass filter de-emphasis circuit
Since it is a signal after H (in the future in terms of time), the first reproduced luminance signal is extended by 18M by the 1Hl extension circuit 71 and then supplied to the terminal 72b of the switch circuit 72. The switch circuit 72 uses the rotating heads 52 and 53 to perform FMI! based on the switching pulse from the waveform shaping circuit 66. During the one-day period when the if degree signal is a reproduction signal, the second reproduction luminance signal input to the terminal 72a is selectively outputted to the output terminal 73, and during the next 1H period, the first reproduction luminance signal input to the terminal 72b is selected. The signal is selectively output to the output terminal 73.

As a result, as schematically shown in FIG. 9(C), reproduced luminance signals are outputted to the output terminal 73 in a temporally regular order.

On the other hand, during one day when the frequency division multiplexed signal is reproduced by the rotary heads 52 and 53, the first . The second reproduction frequency division multiplexed signal is selectively output. The first reproduced frequency division multiplexed signal is supplied to a bandpass filter 74, where the third FM color difference signal having the frequency spectrum shown in FIG. 75.

Further, the second reproduced frequency division multiplexed signal is separated into P waves from the third FM color difference signal by the bandpass filter 76, and is supplied to the terminal 77b of the switch circuit 77. 1
The delay circuit 75 is composed of a COD or the like, and is limited by the transmission band, so it hardly outputs the third FM color difference signal because it has a high frequency.
The terminal 7 of the switch circuit 77 is delayed by one day without attenuating each FM signal in the frequency spectrum indicated by Vl.
7a. The switch circuit 77 is a waveform shaping circuit 66
Based on the switching pulses of the rotary head 52
During the one day period during which the frequency division multiplexed signal is reproduced by 53 and 53, the frequency division multiplexed signal schematically shown in FIG. The input frequency division multiplexed signal schematically shown in FIG. 9 (A) is selected and output.
).

In (B), each 1H period indicated by diagonal lines is a transmission period of the FMli degree signal, but it is not input to the switch circuit 77 due to the switching operations of the switch circuits 62 and 63.

As a result, as schematically shown in FIG. 9(D), the reproduced frequency division multiplexed signal synthesized chronologically in the regular time order is taken out from the switch circuit 77 and sent to the bandpass filters 78 and 79, respectively. The first FM color difference signal separated by the bandpass filter 78 has a low frequency that includes the band of the modulation signal component (color difference signal B-Y) as shown in FIG. After the frequency is converted to a high frequency band by the frequency converter 80 so that the modulated signal components can be separated and demodulated by the FM demodulator 81, the FM demodulator 81
Here, it is demodulated into a reproduced color difference signal 8-Y.

This reproduced color difference signal B-Y is outputted to an output terminal 83 through a low-pass filter de-emphasis circuit 82. On the other hand, the FM audio signal extracted from the bandpass filter 79 is
FM demodulator 84. The signal is output through a low-pass filter de-emphasis circuit 85 to an output terminal 86 as a reproduced audio signal.

On the other hand, the reproduced third FM color difference signal taken out from the bandpass filter 74.76 is FM demodulated by the FM demodulator 87.88 and becomes the first and second reproduced color difference signals (R-Y).
It is said that The first reproduced color difference signal (R-Y) is transmitted to a low-pass filter de-emphasis circuit 89 and a one-day delay circuit 91.
are supplied to the terminal 92a of the switch circuit 92 through the respective terminals 92a of the switch circuit 92.

Further, the second reproduced color difference signal (R-Y) is passed through a low-pass filter de-emphasis circuit 90 to a switch circuit 92.
is supplied to terminal 92b of. The switch circuit 92 is connected to the terminal 92a during one day when the switch circuit 77 is connected to the terminal 77a, and the switch circuit 92 is connected to the terminal 77b during the one day period when the switch circuit 77 is connected to the terminal 77a by the same switching pulse as the switch circuit 77.
During the H period, it is connected to the terminal 92b. As a result, the reproduced color difference signal RY synthesized in time series in the regular time order is taken out from the common terminal of the switch circuit 92 and output to the output terminal 93.

Note that the playback device is not limited to the configuration shown in FIG. 8; the playback system for the color difference signal B-Y and the playback system for the audio signal are
They may be separated and may have the same configuration as the color difference signal RY reproduction system shown in FIG.

FIG. 10 shows another example of a track pattern recorded and formed according to the present invention. In the figure, there is no guard band on the magnetic tape 100 but a track T.

~T42 is formed. Here, the tracks T++ and T+2 . T2+ and T72°T3
1 and T32. Separately in the order of T41 and Ta2, and
Two tracks are recorded at the same time, and the signals recorded on two tracks at the same time are the same as in the previous embodiment, and the point that they are recorded in H-alignment is also the same as in the previous embodiment, but adjacent The two tracks are different in that they are recorded by rotating heads having gaps with different azimuth angles, so a guard band is not required. Therefore, according to this embodiment, although it is not possible to form a track pattern that can be played back compatible with a home VTR, it is possible to improve the utilization efficiency of the magnetic tape more than the track pattern shown in FIG. A circuit for adjusting the phase of the FM signal to be recorded becomes unnecessary.

Note that the present invention is not limited to the above-described embodiments; for example, a dedicated pilot signal may be recorded as the pilot signal, and the modulation method of the audio signal is not limited to frequency modulation, but may include other modulation such as PCM. It may be a method. Furthermore, the modulated audio signal may be multiplexed onto the FM luminance signal, although this results in a slight restriction of the band of the FM luminance signal, which is disadvantageous in terms of resolution. Furthermore, the two types of color difference signals are I signals.

A Q signal may also be used.

Effects of the Invention As described above, according to the present invention, luminance signals and chrominance signals are recorded on separate tracks, and signals of the same type with line correlation are recorded between adjacent tracks. It is possible to obtain a high-quality reproduced color video signal with no noticeable crosstalk, and since there is little or no guard band, tape usage efficiency can be improved compared to conventional camera-integrated VTRs, and electrical-mechanical If variable speed playback is possible without using a conversion element, and if two tracks are recorded and formed at the same time using a rotating head with the same azimuth angle, then magnetic tape recorded on a home VTR can be used. In addition to being able to reproduce the video signals of
If the tracks of a book are recorded and formed using rotating heads with different azimuth angles, guard bands are not required, so tape usage efficiency can be further improved.Furthermore, a circuit is required to force the phase difference between the two types of FM signals to zero. It has a number of features such as being unnecessary.

[Brief explanation of drawings]

FIG. 1 is a block system diagram showing one embodiment of the present invention, and FIG.
Figures (A) and (B) are diagrams showing examples of frequency spectra of signals recorded by the block system shown in Figure 1, respectively;
FIG. 3 is a diagram schematically showing the signals of each part of the block system shown in FIG. 1, and FIGS. 4 and 5 are diagrams showing how the rotary head in the block system shown in FIG. 1 is attached to the rotating body, respectively. , FIG. 6 is a diagram showing a first embodiment of a track pattern recorded and formed according to the present invention, FIG. 7 is a partially enlarged view of the track pattern shown in FIG. 6, and FIG. 8 is a block diagram showing an example of a reproducing device. System diagram, FIG. 9 is a diagram schematically showing the signals of each part of the block system shown in FIG.
1 and 12 are diagrams showing eight examples of conventional track patterns, respectively. 15... Luminance signal input terminal, 16.17... Color difference signal input terminal, 18... Audio signal input terminal, 20°32
．． 39.43.49...addition circuit, 21.25°34
．． 35.41...Frequency modulator, 22,44°47.
71.75.91...1 day delay circuit, 24°33...
・Subtraction circuit, 26.38...Phase detector, 52°52
A, 52B...first rotating head, 53.53A. 53B...Second rotating head, 54,100...Magnetic tape, 56...Rotating drum, 73...Reproduction luminance signal output terminal, 83.93...Reproduction color difference signal output terminal, 86. ...Playback audio signal output terminal.

Claims (1)

Scope of Claims: (1) A magnetic recording method in which recording is performed simultaneously and separately on two adjacent tracks on a magnetic tape by a first and second rotary head, which is repeated for each field, A frequency-modulated luminance signal and a frequency-modulated color signal are alternately switched for each horizontal scanning period on each of the two tracks recorded simultaneously and separately, and
recording a signal obtained by multiplexing a pilot signal onto one of the frequency modulated luminance signal and the frequency modulated color signal;
The horizontal synchronizing signal recording positions of each track of the book are aligned and recorded in the track width direction, and the same type of signals that are different from each other by one horizontal scanning period are recorded in each of the adjacent horizontal scanning periods of the two tracks. A magnetic recording method characterized by: (2) The frequency-modulated luminance signals respectively recorded on the two tracks are frequency-modulated so that the phase difference between them is minimized. magnetic recording method. (3) The frequency modulated color signal is two types of frequency modulated color difference signals with different bands obtained by separately frequency modulating different carrier waves with two types of color difference signals. The magnetic recording method according to item 1. (A) The magnetic recording method according to claim 1, wherein a frequency-modulated audio signal obtained by frequency-modulating a carrier wave with an audio signal is used as the pilot signal. (5) The first and second rotating heads are installed in pairs facing each other on the rotating surface of the rotating body, and record two tracks simultaneously and separately in one field period. One of the first and second rotating heads has a gap of the same first azimuth angle, and the other one of the first and second rotating heads records and forms two tracks simultaneously and separately in the next one field period. The magnetic recording method according to claim 2, wherein the first and second rotary heads are the same and have a gap having a second azimuth angle different from the first azimuth angle. . (6) The first and second rotating heads are mounted in pairs facing each other on the rotating surface of the rotating body, and record two tracks simultaneously and separately in one field period. One of the first and second rotary heads has gaps of first and second azimuth angles different from each other, and the other one records and forms two tracks simultaneously and separately in the next one field period. 2. The magnetic recording method according to claim 1, wherein the first and second rotary heads have a gap of the second and first azimuth angles.