JPS58129894A - Information signal recording and reproducing method - Google Patents

Abstract

PURPOSE:To improve the stability of frequency and phase and to simplify the circuit, by forming the 1st - the 3rd reference signals from the synchronizing signal and the subcarrier chrominance signal and recording the signals almost at the intermediate part between each track of the main tracks. CONSTITUTION:A luminance signal of band limit, a low frequency conversion carrier chrominance signal multiplexed for common band and a carrier modulated at sound signals are superimposed with each other and the result after frequency conversion is taken as a main information signal. As the geometrical change, a spiral and concentric main track is formed and a main information signal is recorded on a rotary recording medium. Further, a synchronizing signal is inputted to an input terminal 21, and the chrominance sub-carrier signal is inputted to an input terminal 22 and the 1st and the 2nd reference signals fp1, fp2 switched alternately at each one rotating period of the rotating recording medium and the 3rd reference signal fp3 inserted to the switching position are formed. The reference signals fp1-fp3 are selected to frequencies interleaved with the horizontal synchronizing signal, mixed at a mixer 47 and recorded almost at the intermediate part between the tracks of the main track.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information signal recording and reproducing method, and even in a recording and reproducing system of a rotating recording medium that does not have a guide groove and has relatively large distortion, cross-modulation distortion and beat interference in demodulated video signals can be avoided. The purpose of this invention is to provide a method for recording and reproducing a plurality of information signals without causing any interference.

The present applicant previously proposed an "information signal recording and reproducing system" in Japanese Patent Application No. 51-38809. In this method, a plurality of reference signals that are different from each other are sequentially and cyclically recorded for each rotation period of the rotating recording medium approximately in the middle between each of the main information signal recording tracks in a spiral or concentric shape. Among the reproduced signals reproduced by the scanner using a well-known method, at least one of the plurality of reference signals reproduced from both sides of the upper information signal recording track is discriminated and reproduced, and tracking is performed based on this. A tracking operation is performed by obtaining a control signal. This method eliminates the need for a scanning needle guide groove, so when applied to the recording and reproducing system of a capacitance detection type rotating recording medium,
It has various other features such as increasing the sliding area of the scanning needle against the recording medium, thereby making the scanning needle extremely long-life, and allowing special playback such as slow-motion playback and still image playback. . However, the above reference signal is recorded and reproduced for tracking purposes,
It is necessary to separate the recording band from the main information signal.

By the way, in a recording/reproducing method in which an information signal is recorded as a change in geometrical shape using countless bits on a rotating recording medium and then reproduced, unlike the case of a magnetic recording/reproducing device, a plurality of information signals are recorded on the same track, e.g. It is necessary to record the video signal and the audio signal in order to extend the playing time, and for this reason, from the viewpoint of the S/N of the reproduced audio, the video signal has been frequency-modulated using an audio carrier that is frequency-modulated. A so-called duty cycle modulation technique, in which the video carrier is pulse width modulated, has been used. In this case, if the distortion in the transmission system is large, cross-modulation distortion occurs between the video carrier and the audio carrier, resulting in a phenomenon in which beat disturbance occurs in the demodulated video signal. One way to reduce this beat interference is to reduce the ratio of the audio carrier to the video carrier.
It cannot be made very small due to the S/N ratio of the demodulated audio, and it cannot be said to be the best method in a system where the transmission system has large distortion.

The present invention is suitable for transmission systems in which distortion in the transmission system is considered to be relatively large, such as recording with laser light and detecting capacitance changes between bits on the recording medium and a scanning needle during playback. The present invention is an information signal recording/reproducing method, and relates to an improvement of the method previously proposed by the applicant of the present invention, and an embodiment thereof will be described below with reference to the drawings.

FIG. 1 is a block system diagram of an embodiment of a recording system according to the method of the present invention, and FIG. 2 is a block system diagram of an embodiment of the main part of FIG. In FIG. 1, 1 and 2 are audio signal sources, respectively;
The audio signal outputted from this is supplied to frequency modulators 3 and 4, and is 3.43 MHz±75 kHz, 3.
73 MHz±75kHz audio carrier FA1. fA
2. Therefore, voice carrier L'k1. rA
2 is within the carrier color signal band (3.58 MH7±500 kl-12) of the NTSC color television signal, but it is of course possible to select other frequencies. These frequencies are selected to be higher than the upper limit frequency of this luminance signal so that the band does not overlap with the separated luminance signal, but there is a risk of interference with other signals to be recorded and reproduced. A frequency that is not very high, for example, a frequency of about 3 MHz to 4 MHz, is selected in consideration of ease of use.

On the other hand, reference numeral 5 denotes a color video signal source, and the NTSC color video signal extracted from this source is supplied to a luminance signal comb filter 6 and a carrier color signal comb filter 7, respectively. The comb-shaped filter 6 has a frequency of 2.56MHz, which will be described later.
In order to perform band sharing multiplexing of carrier color signals that have been low-pass converted to
The output, the separated luminance signal, is supplied to a low-pass filter 8. The low-pass filter 8 lowers the upper limit frequency of the luminance signal by approximately 3
Bandwidth is limited to M1-1z. Further, a carrier color signal with a band of 3.58M1-12±500kl-IZ is extracted from the comb-shaped filter 7 and is input to the color subcarrier generator 9 and the color signal conversion circuit 10, respectively. The color subcarrier generator 9 generates a subcarrier signal from the burst gate pulse generated from the synchronization signal separated by the synchronization signal separation circuit 11 from the output luminance signal of the low-pass filter 8 and the color burst signal in the carrier color signal using a well-known method. - a frequency fsc(N
3.579545 for TSC color video signal
Generates a continuous wave of M1-1z>. On the other hand, the color signal conversion circuit 10 sets the frequency of the continuous wave from the color subcarrier generator 9 to 12/7, beat-converts this signal and the input carrier color signal, and converts the frequency of the continuous wave from the color subcarrier generator 9 into a color subcarrier of 5/7 x rsc. Outputs a carrier color signal whose carrier frequency has been lower-band converted.

This low-pass converted carrier color signal is passed through the low-pass filter 8.
The mixer 12 performs band-sharing multiplexing with the band-limited luminance signal of Mixed depending on level. This mixed signal is frequency modulated by the frequency modulator 15 so that the sync tip of the video signal is 6.0 MHz, the pedestal is 6.7 MHz, the white beak is 8.3 MHz, and the signal is sent to the output terminal 16 as a main information signal.
sent out.

In addition, 17 is an index signal generator, which generates the synchronization signal from the synchronization signal separation circuit 11 and the frequency? An index signal fp3 is generated from the continuous SC wave.

Furthermore, the pilot signal generator 18 generates a pilot signal f P
+, f P2, and after combining these signals with the index signal fP3, the signal is sent out from the output terminal 20 as a pilot signal (hereinafter also referred to as "reference signal j") for tracking control.

The main information signal is input to, for example, a laser light modulator (not shown) and converted into a modulated light beam, which is then applied to a rotating recording medium coated with photoresist in a geometric manner according to the repetition frequency of the information signal. As a shape change, a spiral or concentric main track is formed and recorded simultaneously with the main information signal.

In addition, the pilot signal is input to another laser light modulator (not shown) and converted into a modulated light beam, and the incident optical path to the objective lens is adjusted so that the intermediate portion between adjacent tracks of the main track is is recorded in the same manner as above. Here, the recording track pitch is approximately 1.6 to θμI, and if the track width of the main track is slightly narrower than this, the distance between the tracks of this main rack is approximately 0.6 to 2μI.
The pilot (IF) will be recorded in
The recording track pitch and the track width of the main track may be equal. The recorded recording medium undergoes a well-known processing process and is press-molded in the same way as an audio record.
For example, after a conductive material is deposited thinly, a dielectric material such as styrene is applied to form a recording medium for reproduction.

Next, the circuit section shown by the broken line 19 in FIG. 1 and consisting of the index signal generator 17 and the pilot 1B generator 18 will be explained in more detail with reference to FIG. 2. Hereinafter, for convenience of explanation, an example will be described in which the rotating recording medium is a disk and four fields of NTSC color video signals are recorded per rotation of the disk.

In FIG. 2, reference numeral 21 indicates a synchronization signal input terminal separated by the synchronization signal separation circuit 11, and reference numeral 22 indicates an input terminal for the continuous wave of frequency fsc generated by the color subcarrier generator 9. A synchronizing signal input from the input terminal 21 is supplied to a horizontal synchronizing signal separating circuit 239- and a vertical synchronizing signal separating circuit 26, respectively.

The horizontal synchronizing signal separated by the circuit 23 is applied as a trigger pulse to a monostable multivibrator (hereinafter referred to as MM) 24. The output pulse of MM24 is applied to MM25 as a trigger pulse. As a result, MM24
Pulses adjusted to appropriate positions and appropriate widths by MM25 are taken out from MM25 and supplied to flip-flops 38 and 41 at J-, which will be described later.

On the other hand, the vertical synchronization signal separated by the circuit 26 is counted down to 1/4 by the counter 27, and then triggers the MM28, and the output of the MM28 further triggers the IM29. As a result, similarly to the above, 1/4 of the vertical synchronization frequency, which is set to an appropriate position in MM28 and an appropriate width in MM29, is set.
The Q, δ output pulse of the MN429 having a frequency of is supplied to the input of the J- flip-flop (hereinafter referred to as J-KFF) 30. This position is located within the vertical retrace period of the equalization pulse immediately after the vertical synchronization signal so that the index signal can be easily extracted during playback, and the pulse width is IH (H is the horizontal scanning period). The number is selected from about 11 to about 11.

Since the J-KFF30 is applied with the synchronization signal from the input terminal 21 as a clock pulse, it outputs a signal obtained by resynchronizing the output of the MM29 with the synchronization signal, and sends this signal to the flip-flop (hereinafter referred to as FF) 31 and the gate. Circuit 32.3
3 and is supplied to J-KFF44, which will be described later. This results in
The output counted down by the FF 31 becomes a rectangular wave that repeats logic rOJ, , rlJ with a four-field period.

This rectangular wave is applied to the gate circuits 32 and 33 as gate pulses having opposite phases to each other to gate output the output pulse portion of the J-KFF 30.

On the other hand, the continuous wave of single frequency fsc inputted to the terminal 22 is switched by the waveform shaping circuit 34 to form a rectangular wave, and then applied to the counters 35, 36, 37, and 1/7.
115. Countdown to 1/13. The repetition frequency taken out from the counter 35 is 511.36
357K H7 (= (1/7) x 3.5795
45 MHZ) signal is input to J, said MM2
The Q and o outputs of 5 are applied as clock pulses to the J-KFF 38 which is input, and from this, the output of the MM 25, which has been resynchronized with the output of the counter 35, is sent to the gate circuit 39.
Output to .

In J-KFF38, the output of the counter 35 is the horizontal synchronization signal (
Since it is in a frequency interleaved relationship with the luminance signal), the phase changes with respect to the output of the MM25, and is provided in order to regain synchronization.

The other inputs of the gate circuit 39 are the output of the gate circuit 333 and the output of the counter 35. Therefore, the output of the gate circuit 39 is in the horizontal retrace period and in the J-K period with a period of 4 fields.
The signal is such that the output pulse of the counter 35 exists in a period excluding the output width of the FF 30.

The output of the gate circuit 39 is applied as a trigger pulse to the MM 40, where the pilot signal fp+ is removed and supplied to the mixer 47 with a duty cycle of 50%. 1 Also, 715.909K Hz taken out from the counter 36 above
(-(1/5) x 3.579545MHz
) signal is generated by J-KFF41, gate circuit 42 and MM43 as a pulse with a duty cycle of 50% during the period excluding the output width of J-KFF30 during the horizontal retrace period with a period of 4 fields. and the pilot signal fl
)2 to the mixer 47.

Index signal ff13 is generated in almost the same way, but unlike fD+ and flllz, only the output pulse period of J-KFF30 is generated at 275.34961K Hz (
= (1/13) x 3,579545 MHz
), the output of the counter 37 is applied as a clock pulse to the J-KFF 44 which inputs the outputs Q and o of the J-KFF 30 to J, and is also applied to the gate circuit 45. The gate circuit 45 is J-
The output signal of the counter 37 is gate-outputted using the output pulse of the KFF 44 as a gate pulse, and the MM 46 is triggered. This results in a duty cycle of 5 compared to MM46.
The pulse of 275.34961KH2 set to 0% is supplied to the mixed 13-combined book 47 as the index signal f113.

The above fp+*fDz and fDz are added together in a mixer 47, and guided from a terminal 48 to a terminal shown at 20 in FIG. 1 as a reference signal.

As a result, the reference signal fp+ + fDz is recorded every four field periods and in correspondence with the horizontal blanking period of this video signal in order to avoid beat interference with the video signal recorded on the main track. However, fDz is recorded at the recording switching position.

The reference signals fp+, fDz, fi3 are the counter 3
7°44.48, respectively, the horizontal scanning frequency is 1. /2
Since the frequency is selected to be an odd multiple of , the brightness If fj
There is a frequency interleaving relationship with the number i, and
The band is different from the low-pass converted carrier color signal band.

Therefore, when recording fp+ and frh continuously, it is necessary to lower the recording level to a certain extent in order to reduce the beat interference caused to the video signal, but the recording level must be at a level that provides a sufficient S/N ratio. It is possible to secure In this way, fpl.

If fla2 is recorded as a continuous signal, trouble 1 during playback
4-4: In addition to improving the accuracy and stability of the servo control, there are advantages such as jitter detection can be carried out continuously.

Note that the pilot signal fp1. fr2. Although fr3 is shown as a rectangular wave output in the figure, it is also possible to record it as a sine wave by passing it through a reduction filter.

FIG. 3 shows an example of the frequency spectrum of a recorded signal by the recording system of FIGS. 1 and 2. ■ is the carrier wave shift frequency band of 2.3M)lz of the frequency-modulated luminance signal, fa is the 6MHz frequency corresponding to the sync chip,
fb is the frequency of 687MHz corresponding to the pedestal, f
c indicates a frequency of 8.3 MHz corresponding to the white beak. Further, I[L and I[U indicate the lower sideband and upper sideband of the frequency-modulated luminance signal. I[[L, I[
[u is audio carrier FAI.

The lower sideband and upper sideband of a signal obtained by further frequency modulating fA2 are shown. Here, the audio carrier rAt 1f A 2
C. As mentioned above, this is a signal obtained by frequency modulating carrier waves of 3.43 MHz and 3.73 MHz with an audio signal, and its frequency spectrum is indicated by ■.

However, the audio signal is frequency modulated twice.

Furthermore, V is a mixer shown at 12 in Figure 1, and the upper limit frequency is approximately 3.
This shows the band of the carrier color signal that has been low-pass converted and is band-sharing multiplexed to the luminance signal band-limited to MHz, and in this embodiment, as an example, it is 2.5568178 MHz (=5/7
fsc ) occupies a band of ±500KH7. In addition, the first sideband generated by frequency modulating the low-pass converted carrier color signal in the band indicated by ■ is VIL,
VILI and the second sidebands are denoted by VIrL and VIIu, respectively.

In FIG. 3, the frequency spectrum drawn by the solid line is the frequency spectrum of the signal recorded on the disc.

Note that fD+, fr21 and fr3 are located in the frequency band below the band VTIL. Separating the occupied bands of the pilot signal and the main information signal is necessary because they are reproduced by the same reproduction scanner.

Figure 4 shows a disc recorded by the method of the present invention.
1 schematically shows an outline of the track pattern on 1. In the figure, the solid line indicates the track center line of the main track on which the main information signal is recorded, and the pilot signal (reference signal) fp+ is recorded, a pilot signal (reference signal) fi2 is recorded at the position indicated by the An index signal (reference signal) fr)3 is recorded on the track or the intermediate portion mentioned above. Note that the recording position of the reference signal f'rJs is recorded in one of the vertical blanking period recording portions recorded at four locations corresponding to the rotation of the disk.

FIG. 5 shows a block diagram of an embodiment of the regeneration system of the method of the present invention. As mentioned above, in order to eliminate beat interference to the demodulated video signal during playback, an audio carrier is selected at a frequency higher than the upper limit frequency of the video band, and this is superimposed on the band-limited luminance signal, and the carrier color signal is Low frequency conversion is performed to a relatively high frequency side within the luminance signal band, and band sharing multiplexing is performed with the luminance signal,
In the case of a disk on which all of these are frequency-modulated and recorded, the information signal reproduced by known means such as detecting a change in capacitance between the disk and the scanning needle has a longer time constant than the input terminal A51. The signal is supplied to the AGC circuit 52, where it is kept at a constant level. Here, the method for reproducing the reference signal is that when the reproducing scanning element (scanning needle in this case) is accurately scanning the main track, the fD+ and fpz recording tracks are not scanned, so fpl and fpz are not reproduced.
fp+, fp only when tracking deviation occurs
fp when one of the pilot signals of z is regenerated and when scanning accurately over the main
+l There is a case of constant reproduction of fpl and fp2 in which the relative reproduction level ratio of fr2 is constant and occurrence of tracking deviation is detected when this relative level ratio is no longer constant. In any case, when tracking deviation occurs, fD+ or ft)z is reproduced and exists in the above-mentioned reproduced signal.

The reproduced signal from the AGC circuit 52 is passed through a bandpass filter 53.
Only the reference signal frequency band components are filtered by 18- and supplied to tuned amplifiers 54, 55, and 56, respectively, fD+, fl2. Each of the fpz reference signals is tuned and amplified. The AGC circuit 52 is a bandpass filter 5
The output reproduction reference signal of 3 is supplied as a control signal, fp
It operates so that the sum of the reproduction levels of + and fpz is always constant. Output reference signal fp1 of tuned amplifier 54.55
．． fpz becomes an input to a tracking servo circuit 59, where a tracking error voltage corresponding to the level difference of the envelope detection output of, for example, fD+*fpz is applied from a terminal 6o to a well-known tracking servo mechanism. Here, the reference signal (index signal) is the reference signal fp+ or fl)2 recorded on the outer track of the tracks on both sides of the main track during one rotation period of the disk when the recording position of fl3 is considered as the starting point, and the inner track. The recording positional relationship of the reference signal fF)2 or fp+ recorded on the side track is as follows:
As can be seen from FIG. 4, the inputs fρ+ and fρ2 of the tracking servo circuit 59 are required to properly track the main track because the inputs fρ+ and fρ2
must be substantially reversed every rotation of the disk.

Therefore, the output signal fp3 is tuned and amplified by the tuned amplifier 56 (because the output signal fp3 is output at the 2-nephew switching point of Dl+fDz for each rotation period of the disk, the index signal fpg
The FF 58 is triggered through the detection circuit 57, and the square wave obtained from this repeats the logic rOJ and r1J at the phase where fpz exists for each rotation of the disk is sent to the tracking servo circuit 59. Switching is performed to switch the polarity of fp+fl)2. (A correct error signal can be obtained by applying the signal as a signal.)

Specifically, in the five tracking servo circuits, the envelope detection output of each output reference signal of the tuned amplifiers 54 and 55 is connected to an inverting input terminal and a non-inverting input terminal of a differential amplifier (not shown) via a switch circuit. This differential amplifier generates and outputs a tracking error signal, but the switch circuit described above switches the input to the differential amplifier every time the signal fD3 is regenerated. The reference signal fp+ reproduced from the outer circumferential side of the disc is input to the input terminal.
or fpz is always supplied, and the reference signal fρ2 or rpl reproduced from the inner circumferential side of the disk is always supplied to the non-inverting input terminal.

On the other hand, the reproduced signal input from the input terminal 51 is also supplied to the bandpass filter 61, where the reference fA signal is removed, and then FM demodulated and de-emphasized by the FM demodulator 62 to produce the video signal and the audio carrier fAI. l fA
2 superimposed signals. This superimposed signal is separated by a color signal/luminance signal separation circuit 63 into a carrier color signal and a luminance signal which have been low frequency converted. The low-pass conversion carrier color signal is supplied to a color signal conversion circuit 64, where a variable frequency oscillator (hereinafter referred to as V
The beat component of the difference from the (12/7) fsc signal generated from the (5/7) fsc signal from (denoted as FO) 66 is removed and returned to the original carrier color signal at the color subcarrier frequency fsc. At the same time, the jitter component is also canceled. This is so-called A, in which the output 5fsc/7 of the VFO 66 is counted down to 115 by the counter 67, the phase is compared with the reproduced f11+ from the tuned amplifier 54 as 511KH7 by the phase comparator 65, and the error voltage is returned to the VFO 66.
This is because a PC loop is being created.

The above reproduced carrier color signal is mixed in a mixer 69 with a reproduced luminance signal that has entered from the separation circuit 63 through a low-pass filter 68 with an upper limit cutoff frequency of 3Mt-1z, and is led to an output terminal 76 as a reproduced color video signal. It will be destroyed.

The above demodulated V5 signal before applying de-emphasis is passed through bandpass filters 70 and 71 to voice key A/rear fAI.
, fA2 are filtered out and sent to an FM demodulator 72 .
73, the signal is FM demodulated into the original audio number 113, and is led to output terminals 74 and 75.

FIG. 6 shows a block diagram of the main parts of another embodiment of the regeneration system of the method of the present invention. In the figure, the same parts as in FIG. 5 are given the same reference numerals. Output regenerated pilot signal fρ+*fri2 of tuned amplifier 54.55 is a ringing oscillator 101. After being made into a continuous wave in step 102, an amplitude controller 103. 104 and a frequency discriminator 105. 10
6, where the frequency is discriminated, and then the mixer 107
mixed in. A speed error signal is taken out from this mixer 107 and outputted from a terminal 108 to a known speed error correction mechanism (not shown) such as an arm stretcher.

It should be noted that the method of the present invention is not limited to the above-mentioned embodiments, and may be used instead of fp3 or together with fp3 as an index signal, for example, from one day (t1 is the horizontal scanning period) to several days immediately after the vertical synchronization signal. A single frequency (which may be the same frequency as fD3) and/or a gray level signal may be superimposed on the luminance signal for a period of .

In addition, PAL system other than NTSC system or SECA system
Other standard color video signals such as M format can also be recorded.

As described above, the information signal recording and reproducing method according to the present invention records a main information signal on a rotating recording medium by forming a spiral or concentric main track as a change in geometrical shape, in a band-limited manner. a luminance signal, a low-band-converted carrier color signal that is band-sharing multiplexed into a high frequency part within this luminance signal band, and one or more signals modulated with an audio signal having a frequency higher than the upper limit frequency of the luminance signal. The first and second reference signals are alternately switched every rotation period of the l111 transfer recording medium, and the first and second reference signals are inserted at this switching position. The reference signal of No. 3 is selected to have a frequency that occupies a frequency band lower than the S self-recording band of the main information signal, is a completely different frequency, and is frequency interleaved with the horizontal synchronizing signal. The first and second reference signals are recorded in a substantially intermediate portion between each track of the main track, and the third reference signal is recorded in the main track or a substantially intermediate portion between each track of the main track. However, during reproduction, the first to third reference signals are respectively discriminately reproduced from among the reproduced signals picked up and reproduced by a reproduction scanner that scans on the rotating recording medium, and the reproduced first and second reference signals are reproduced. The signal is supplied to a tracking control circuit to compare the levels of the detection outputs of both reference signals and generate a tracking error signal for correcting the tracking deviation of the reproducing scanner from the main track, and the third reference signal. each time the page is played.
1 the first and second racking control circuits.
Since the polarity of the reference signal is essentially inverted,
It has the following features.

■ Even if the distortion in the transmission system is relatively large, the single carrier characteristic prevents beat interference from demodulated video signals.
A luminance signal, a carrier color signal, and one or more audio signals can be recorded and played back on the same track without having to do so.

(2) Since the first to third reference signals are generated by counting down the color subcarrier, they have extremely high frequency and phase stability.

■ By using the reference signal instead of the color burst signal during reproduction, the reproduction signal circuit can be simplified.

■ Since it is a single carrier, there is no cross-modulation distortion that occurs when transmitting a signal through so-called duty cycle modulation.

(2) The first and second reference signals can be recorded continuously at a recording level that provides a sufficient S/N ratio.

■ When the reference signal is recorded continuously in connection with ■ ■, the accuracy and stability of the tracking servo during playback can be improved by 1 compared to when it is recorded intermittently. The accuracy of speed error detection can also be improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of a recording system according to the method of the present invention, FIG. 2 is a block diagram of an embodiment of the main part of FIG. 1, and FIG. 3 is a frequency diagram of a recording signal according to the method of the present invention. A diagram showing an example of a spectrum, FIG. 4 is a diagram schematically showing an example of a track pattern of a rotating recording medium recorded by the method of the present invention, and FIG. 5 is a block system of an embodiment of the reproduction system of the method of the present invention. 6 are block diagrams of essential parts of another embodiment of the regeneration system of the method of the present invention. 1.2... Audio signal source, 3.4.15... Frequency modulator, 5... Color video signal source, 6... Luminance signal comb filter, 7... Color signal comb filter , 8...
・Low pass filter, 9...Color subcarrier generator, 10...
・Color signal conversion circuit, 16...Main information signal output terminal, 1
7... Index signal generator, 18... Pilot signal generator, 27.35-37.67... Counter, 26-52... AGC circuit, 59... Tracking servo circuit, 62.72 .73...FM demodulation circuit, 63...
- Color signal/luminance signal separation circuit, 64...color signal conversion circuit. =27-

Claims (1)

[Claims] The main information signal, which is recorded on a rotating recording medium by forming a spiral or concentric main track as a change in geometrical shape, is divided into a band-limited luminance signal and a high frequency part within the luminance signal band. Frequency modulation is performed by superimposing a low-pass conversion carrier color signal that has been band-sharing multiplexed on the chrominance signal and one or more carriers modulated with an audio signal having a frequency higher than the upper limit frequency of the luminance signal. a first signal and a second signal which are switched to alternate n every rotation period of the rotating recording medium;
The reference signal and the third reference signal inserted at this switching position occupy a frequency band lower than the recording band of the main information signal, and have different frequencies from each other to achieve horizontal synchronization. The first and second reference signals are selected to be frequency interleaved with the signal, and the first and second reference signals are recorded approximately in the middle between the respective tracks of the main track, and the third reference signal is recorded on the main track or the main track. The first to third reference signals are recorded approximately in the middle between each track of the recording medium, and during reproduction, the first to third reference signals are selectively reproduced from among the reproduction signals picked up and reproduced by a reproduction scanner that scans the rotating recording medium; The reproduced first and second reference signals are supplied to a tracking control circuit, the levels of the detection outputs of the two reference signals are compared, and a tracking error signal is generated for correcting and overcoming the tracking deviation of the reproduction scanner from the main track. Information characterized in that the polarities of the first and second reference signals that are generated and supplied to the tracking control circuit are substantially inverted each time the third reference signal is reproduced. Signal recording and playback method.