JPS58129895A - Information signal reproducer - Google Patents

Abstract

PURPOSE:To prevent beat interference and to simplify the circuit, by forming a tracking error signal from the 1st - the 3rd reference signal recorded almost at the intermediate part between main tracks and correcting the shift in reproduced scanning element. CONSTITUTION:Recording information picked up at the reproducing scanning element is selected for the frequency at an AGC circuit 52, a band pass filter 53, and tuning amplifiers 54-56, and the 1st - the 3rd reference signals fp1-fp3 are reproduced and a main information signal is reproduced at a band pass filter 61 and an FM demodulator 62. The 1st and the 2nd reference signals fp1, fp2 are applied to a tracking servo circuit 59 to obtain the difference amplified output of the detection output of both the reference signals fp1, fp2 and the tracking shift of the reproducing scanning element from the main tracks is corrected. Further, the polarity of the 1st and the 2nd reference signals fp1, fp2 is inverted with the 3rd reference signal fp3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an information signal reproducing device, and even in a reproducing device for a rotating recording medium that does not have a guide groove, which causes relatively large distortion, cross-modulation distortion and beat disturbances occur in the video signal. It is an object of the present invention to provide a device capable of reproducing a plurality of information signals without any trouble.

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 main information signal recording track is discriminately 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,
The sliding area of the scanning needle against the recording medium can be increased, thereby making the scanning 14 extremely long-life, and it also has various other features such as being able to perform special reproductions such as slow-motion reproduction and still image reproduction. . However, the reference signal shown in "" is recorded and reproduced for tracking purposes, and needs to be separated from the recording band of 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 both the video signal and the audio signal in order to extend the playing time, and for this reason, from the viewpoint of 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 an information signal reproducing device suitable for a transmission system in which the distortion of the transmission system is considered to be relatively large, such as detecting a capacitance change between a bit on a recording medium and a scanning needle,
The present invention also relates to an improvement of the system previously proposed by the applicant, and an embodiment thereof will be described below with reference to the drawings.

FIG. 1 is a block system diagram of an example of a recording system of a rotary recording medium to be reproduced by the apparatus of the present invention, and FIG. 2 is a block system diagram of an example of the main part of FIG. In Fig. 1, reference numerals 1 and 2 are audio signal sources, and the audio signals outputted from these are supplied to frequency modulators 3 and 4, and are 3.43MH7±75 kHz.
z, 3.73 MHz±75kHz is modulated onto audio carriers fA+, fA2. Therefore, voice carrier fA1. fA2 is the band of the carrier color signal of the NTSC color television signal (3,58MH2±500k)
It is of course possible to select other frequencies for 5- within (z). These frequencies are set so that the bands do not overlap with the separated luminance signal.
The frequency is selected to be higher than this brightness signal upper limit frequency, but it is not very high, for example, 3M), taking into account the conflict with other signals to be recorded and reproduced, ease of recording and reproduction, etc. A frequency of about 1z-4MH2 is selected.

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 is a 2.56MH2
In order to perform band sharing multiplexing of the carrier chrominance signal that has been low-pass converted to 2 MHz, a comb-type filter operation is performed in a band of 2 MHz or higher, and the output of the separated luminance signal is passed through a low-pass filter 8.
supply to. The low-pass filter 8 band-limits the upper limit frequency of the luminance signal to about 3 MHz. Also, the band of 3.58 MH2±500 kl-1z is obtained from the comb-shaped filter 7! The two color sending signals are taken out and become inputs to the color subcarrier generator 9 and the color signal conversion circuit 10, respectively. The chrominance subcarrier 6-wave generator 9 generates a burst gate pulse generated from the sync signal separated by the sync signal separation circuit 11 from the output luminance signal of the low-pass filter 8 and a color burst signal in the carrier chrominance signal using a well-known method. , a continuous wave having a frequency fsc (3.579545 MILz for an NTSC color video signal) equal to the color subcarrier frequency of the carrier color signal is generated.

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 to 5/7×f.
A low-pass converted carrier color signal having a color subcarrier frequency of sc is output.

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 the audio carrier fA1. It is mixed with fA2 at an appropriate level relationship. This mixed signal is processed by a frequency modulator 15 to adjust the sync tip of the video signal to 6. The frequency is modulated so that the OMH2 and pedestal are 6.7 MHz and the white beak is 8.3 MHz, and then sent out from the output terminal 16 as the main information signal.

Further, 17 is an index signal generator which generates an index signal fP3 from the synchronization signal from the synchronization signal separation circuit 11 and a continuous wave of frequency fsc.

Furthermore, the pilot signal generator 18 generates pilots (ffi signals fP1 and fP2), combines these signals with the index signal fP3, and then outputs them from the output terminal 20 as a pilot signal (hereinafter also referred to as "reference signal") for tracking control. send out.

The above-mentioned main information signal is input to, for example, a laser light modulator (not shown) and converted into a modulated light beam. A spiral or concentric main track is formed as a change in the shape of the main information signal and is 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 light path to the objective lens is adjusted to C is recorded in the middle part in the same manner as above. Here, the recording track pitch is about 1.6 to 6 μm, and if the track width of the main track is slightly narrower than this, the pilot signal is recorded in about 0.6 to 2 μm between the main tracks. will be done. Note that the recording track pitch and the track width of the main track may be equal. The recorded recording medium undergoes a well-known 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, and the recording medium is made into a recording medium for playback.

Next, the circuit section consisting of the index signal generator 17 and the pilot signal generator 18, indicated by the broken line 19 in FIG. 1, will be explained in more detail with reference to FIG. 2. 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 on this disk by nine rotations.

In FIG. 2, 21 is a synchronizing signal input terminal separated by the synchronizing signal separation circuit 9-11, and 22 is an input terminal for a continuous wave of single 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 separation circuit 23 and a vertical synchronizing signal separation circuit 26, respectively.

The horizontal synchronization signal separated by the circuit 23 is applied as a trigger pulse to an instep stable 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 MM2S and supplied to flip-flops 38 and 41 at J-, which will be described later.

On the other hand, the vertical synchronization signals I and - separated by the circuit 26 are counted down to 1/4 by the counter 27, and then the MM28
, and further triggers MM29 with the output of MM28. As a result, similarly to the above, 1/1/2 of the vertical synchronization frequency, which is set to an appropriate position by MM28 and an appropriate width by MM29, is set.
The Q, δ output pulse of M M 29 with a frequency of 4 is J-,
, is supplied to the input of the flip-flop 10- (hereinafter referred to as T"J-KFF) 30. This position is placed at the equalization position immediately after the vertical synchronization signal so that the index signal can be easily extracted during playback. It is within the vertical retrace period of the pulse, etc., and the pulse width is IH (H
is selected to be a horizontal scanning period) to several times a period.

Since the J-KFF 30 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 MM 29 with the synchronization signal, and this is sent to the flip 70 tube (hereinafter referred to as FF) 31, Gate circuit 32.3
3 and J-KF “44” described below. As a result,
The output counted down by the FF 31 becomes a rectangular wave that repeats the logic rob and rlJ in 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 H2 (= < 1 /7) x 3,57
A signal of 9545 MHz) is input to the above M
The Q and o outputs of M25 are applied as clock pulses to the input J-KFF38, and from this, the counter 35
The output of the MM25, which has been resynchronized with the output of the gate circuit 39, is outputted to the gate circuit 39.

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 33 and the output of the counter 35, so that the output of the gate circuit 39 is horizontally M! During the period and J-KF
The signal is such that the output pulse of the counter 35 exists in a period excluding the output width of F30.

The output of the gate circuit 39 is applied as a trigger pulse to the MM 40, where a pilot signal fρ1 is obtained and supplied to the mixer 47 with a duty cycle of 50%.

Also, 715.90 taken out from the counter 36
9K 1-12 (= (1/5) x 3.5
79545M1lz) is the same as above, J-K
The FF 41, gate circuit 42 and MM 43 generate a pulse with a duty cycle of 50% during the horizontal retrace period excluding the output width of the J-KFF 30 with a 4-field period.
It is supplied to the mixer 47 as a pilot signal rh.

The index signal fp3 is also generated in almost the same way.Unlike the Relca, fp+, and fp2, the index signal fp3 is 275.34961K H2(-(1
/13) x 3.579545 MH2) The output of the counter 37 is J-
J-KFF with outputs Q and o of KFF30 input to J
44 as a tarock pulse, and is applied to gate circuit 45. The gate circuit 45 is J-KFF
Using the output pulse of counter 37 as a gate pulse, the output signal of counter 37 described in 13- above is output as a gate pulse, and M N = 1.
trigger 46. As a result, a pulse of 275.34961KH7 with a duty cycle of 50% is supplied from the MM46 to the mixer 47 as the index signal fi3.

The above fD+ + fl'2 and fp3 are added together in a mixer 47, and are sent as a reference signal from a terminal 48 to 20 in FIG.
It is led to the terminal indicated by .

As a result, the reference signals rl)+ and fp2 are set every four field periods and correspond to the horizontal blanking period of the video signal to avoid beat disturbance to the video signal distributed on the main track. However, at that recording switching position, fp3 is recorded.

The reference signals fD+, frh, fl)3 are each converted to 1/1 of the horizontal scanning frequency by a counter 37°44.48.
Since the frequency is selected to be an odd multiple of '2, the brightness (E
It is in a frequency interleaved relationship with the i number, and has a different band from the carrier color signal band subjected to the low frequency conversion. Therefore, J records fD+ and frh continuously.

In this case, it is necessary to lower the recording level to some extent in order to reduce the beat interference caused to the video signal, but it is possible to maintain a recording level that provides a sufficient S/N ratio. In this way, fp+ 1fi2 is continuously (+
When recording with No. J, there are advantages such as improved accuracy and stability of tracking servo during playback, and continuous jitter detection.

Although the pilot signals fp+, fe2*fp3 are shown as rectangular wave outputs in the figure, they can also be recorded as sine waves by passing them through a reduction filter.

FIG. 3 shows an example of the frequency spectrum of the recording signal by the recording system of FIGS. 1 and 2. ■ is the carrier wave shift frequency band of 2.3M@z of the frequency-modulated luminance signal, fa is the frequency of 6MH2 corresponding to the sync chip, r
b is the frequency of 6.1 MHz corresponding to the pedestal, f
c indicates a frequency of 8.3 MHz corresponding to white beak. Further, IIL and IIU indicate the lower sideband and upper sideband of the frequency-modulated luminance signal. DIL, I[u
is the audio carrier rAt.

The lower sideband and upper sideband of a signal obtained by further frequency modulating fΔ2 are shown. Here, the audio carrier fAl.

As mentioned above, fA2 is 3.43MH7 and 3.73M
It is a signal obtained by frequency modulating a Hz carrier wave with an audio signal,
Its frequency spectrum is indicated by ■.

That is, 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.
The band of the carrier color signal that has been low-pass converted and that is band-sharing multiplexed to the luminance signal that is band-limited to MHz is shown.
c) It occupies a band of ±500KH7. Also, ■
VIL and VI
In U, the second sidebands are denoted by VIIL and VIILI, respectively.

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

Note that fpl, fp2. fp3 is located in the frequency band below band VIr. Separating the occupied bands of the pilot signal and the main information signal is inevitable because they are reproduced by the same reproduction scanner.

FIG. 4 schematically shows an outline of a track pattern on a disk that is reproduced by the apparatus of the present invention. 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 The pilot signal (reference signal) [p2 is recorded at the position indicated by the X mark, and the switching position (position shown with diagonal lines) for the reference signals fp+ and fD2 is also recorded, and the main track is Alternatively, an index signal (reference signal) fp3 is recorded in the intermediate portion.

Note that the recording position of the reference signal fp3 is disk rotation address 4.
One of the vertical blanking period recording portions recorded in the
recorded within the vertical blanking period recording section.

Next, to explain the apparatus of the present invention, FIG. 5 shows a block system diagram of one embodiment of the apparatus 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 of 17-waves higher than the upper limit frequency of the video band, and this is superimposed on the band-limited luminance signal, and the carrier color is The signal is low frequency converted to a relatively high frequency side within the luminance signal band and band-sharing multiplexed with the luminance signal C3. An information signal reproduced by a well-known means such as capacitance change detection is supplied to an AGC circuit 52 having a longer time constant than an input terminal 51, where it is kept at a constant level. Here, as a method for reproducing the reference signal, when the reproducing scanner (here, the scanning needle) is accurately scanning the main 1-rack, fp+ is used.

Since the fpz recording track is not scanned, fl)+, f
Relative reproduction of fD+ * fp2 when one of the pilot signals of fp2 is regenerated and when the main track is being scanned accurately fpl, fe, where the level ratio is constant and the occurrence of tracking deviation is detected when this relative level ratio is no longer a constant value.
z There is a case of constant playback. In any case, when tracking deviation occurs, 18-fl)+ or fpz is reproduced and is present in the above-mentioned reproduced signal.

The reproduced signal from the AGC circuit 52 is passed through a bandpass filter 53.
One wave of only the reference signal frequency band component is supplied to the tuned amplifiers 54, 55, and 56, respectively, and [ρ+*fp
Each of the z*fpg reference signals is tunedly amplified. The AGC circuit 52 is supplied with the output reproduction reference signal of the bandpass filter 53 as a control signal, and operates so that the sum of the reproduction levels of fpl and fpz is always constant. Output reference signal fp1. of tuned amplifier 54.55. fpz becomes an input to the tracking servo circuit 59, where, for example, f
A tracking error voltage corresponding to the level difference between the envelope detection outputs of p+ and fpz is applied from the terminal 6o to a well-known tracking servo mechanism. Here, the reference signal (index signal) [reference signal fp+ or fp 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 p3 is considered as the starting point.
As can be seen from FIG. 4, the recording positional relationship between z and the reference signal fe2 or fp+ recorded on the inner track changes alternately every period of one disk rotation. It is necessary to substantially invert the inputs fρ+ and fpz of the tracking servo circuit 59 every rotation of the disk.

Therefore, the signal fps which is tuned and amplified by the tuning amplifier 56 and is outputted becomes fp+ for each rotation period of the disk.

Since it is output at the recording switching point of fpz, the index signal fp3 is passed through the detection circuit 57 to trigger the FF 58,
The resulting rectangular wave that repeats the logical rob and rIJ at the phase where fpz exists every disk rotation is sent to the tracking servo circuit 59 as fp+.

A correct error signal can be obtained by applying the signal as a switching signal for switching the polarity of fl12.

Specifically, the tracking servo circuit 59 connects the envelope detection output of each output reference signal of the tuned amplifiers 54 and 55 to an inverting input terminal and a non-inverting input terminal of a differential amplifier (not shown) via a switch circuit. A tracking error signal is generated and output from this differential amplifier.The above switch circuit switches the input to the differential amplifier every time the signal fD3 is reproduced. The reference signal fl)+ or fpz reproduced from the outer circumferential side of the disk is always supplied to the inverting input terminal, and the reference signal fp2 reproduced from the inner circumferential side of the disk is supplied to the non-inverting input terminal.
Or fD+ is always supplied.

On the other hand, the reproduced signal input from the input terminal 51 is also supplied to the bandpass filter 61, where the reference 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, It is assumed to be a superimposed signal of fA2. 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 VFO) is used.
The beat component of the difference from the (12/7) fsc signal generated from the (5/7) fsc signal from 66 (denoted as ) 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 the output 5fSO of VFO66
/7 is counted down to 115 by the counter 67,
511KH2, the phase of the reproduced fpl from the tuned amplifier 54 is compared with the phase comparator 65, and the error voltage is output to VFO6.
This is because it creates a so-called A, PC loop that returns to 6.

The above-mentioned reproduced carrier color signal is mixed with the reproduced luminance signal inputted from the separation circuit 63 through a low-pass filter 68 with an upper limit cut-off frequency of 3 MH2 in a mixer 69, and is guided to an output terminal 76 as a reproduced color video signal.

The above de-8 superimposed signal before applying de-emphasis is passed through bandpass filters 70 and 71 to the audio carrier f A I
* f A 2 is extracted in seven waves, converted to FM III by an FM demodulator 72.73, and then converted into the original audio signal and guided to an output terminal 74.75.

FIG. 6 shows a block system diagram of the main parts of another embodiment of the device of the present invention. In the figure, the same parts as in FIG. 5 are given the same reference numerals. The regenerated pilot signals fp+ and fpz output from the tuned amplifiers 54 and 55 are output from the ringing oscillators 101 and 22, respectively. After being made into a continuous wave in step 102, an amplitude controller 103. 104 to frequency discriminators 105 and 106, where the frequency is discriminated, and then the mixer 1
Mixed at 07. 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.

Note that the device of the present invention is not limited to the above-described embodiment, and can be used instead of fp3 or as an index signal together with I)z, for example, IH(H) immediately after the vertical synchronization signal.
is a rotating recording medium recorded by superimposing one or both of a single frequency (this may be the same frequency as fp3) and a gray level signal on a luminance signal for a period of from (horizontal scanning period) to several H. It can also be played.

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

As described above, the information signal reproducing apparatus according to the present invention converts the main information signal recorded on a rotating recording medium by forming a spiral or concentric main track as a change in geometrical shape into a band-limited main track. One or more signals modulated with a luminance signal, a low frequency converted carrier color signal that is band-sharing multiplexed into a high frequency part within this luminance signal band, and an audio signal with a frequency higher than one limit frequency of the luminance signal. The first and second reference signals are alternately switched every rotation period of the rotating recording medium, and the third reference signal is inserted at this switching position. The first and second reference signals are selected to have frequencies that occupy a frequency band lower than the recording band of the main information signal, are different from each other, and are frequency interleaved with the horizontal synchronizing signal. Rotational recording, wherein the second reference signal is recorded on the main track at a substantially middle portion between each track, and the third reference signal is recorded on the main track or at a substantially middle portion between each track of the main track. A device for reproducing a medium, comprising: a reproducing scanner that scans the rotating recording medium to pick up and reproduce a recorded green signal; a frequency selection means for selecting the frequencies of each signal and taking them out separately; a reproduction circuit for demodulating and reproducing the main information signal from among the reproduction signals from the reproduction scanner; a tracking control circuit that is supplied with two reference signals and differentially amplifies the detection outputs of these two reference signals to generate a tracking error signal for correcting a tracking deviation of the reproducing scanner from the main track; and means for substantially inverting the polarities of the first and second reference signals supplied to the tracking control circuit each time the third reference signal is reproduced by the means,
It has the following features.

■ Even if the distortion in the transmission system is relatively large, the brightness signal, carrier color signal, and one or more audio signals can be transmitted from the same track without causing beat interference in the demodulated video signal due to the single carrier characteristic. Can be played.

■ By using the reference signal in place of the color burst signal during reproduction, the reproduction signal circuit can be easily constructed.

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

■ If the reference signal is recorded continuously in conjunction with Accuracy can also be improved.

[Brief explanation of drawings]

FIG. 1 is a block system diagram of an example of a recording system of a rotating recording medium to be reproduced by the apparatus of the present invention, FIG. 2 is a block system diagram of an example of the main part of FIG. FIG. 4 is a diagram schematically showing an example of a track pattern of a rotating recording medium to be reproduced by the apparatus of the present invention, and FIG. FIG. 6 is a block system diagram of an embodiment of the apparatus. FIG. 6 is a block system diagram of main parts of another embodiment of the reproducing apparatus of the present invention. 26-1.2... Audio signal source, 3.4.15... Frequency modulator, 5... Color video signal source, 6... Luminance signal comb filter, 7... Color signal Comb-shaped filter, 8.
...Low pass filter, 9...Color printing carrier wave generator, 10.
...color signal conversion circuit, 16...main information signal output terminal,
17... Index signal generator, 18... Pilot signal generator, 27.35-37.67... Counter, 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. 27-1

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 alternately 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, and are horizontal synchronizing signals. The first and second reference signals are selected to have a frequency interleaved with the main track, 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 at a substantially intermediate portion between the tracks. A device for reproducing a rotating recording medium recorded approximately in the middle between each track, comprising: a reproducing scanner that scans the rotating recording medium to pick up and reproduce a recorded green signal; a frequency selection means for selectively frequency-selecting each of the first to third reference signals from among the reproduced signals and extracting them separately; and a reproduction circuit for demodulating and reproducing the main information signal from among the reproduction signals from the reproduction scanner; the first frequency extracted from the frequency selection means;
and a tracking control circuit that is supplied with a second reference signal and differentially amplifies the detection outputs of both reference signal sequences to generate a tracking error signal for correcting a tracking deviation of the reproducing scanner from the main track; and means for actually inverting the polarities of the first and second reference signals supplied to the tracking control circuit each time the third reference signal is reproduced by the frequency selection means. Characteristic information signal reproducing device.