JPS63142573A - Recording and reproducing device for disk - Google Patents

Abstract

PURPOSE:To use a time base variation detecting part in common, and to reduce cost by dividing a bit of information and converting it two signals, and adding a synchronizing signal provided with a prescribed phase difference, to each of them. CONSTITUTION:A luminance signal Y is delayed by 1/2H, color difference signals R-Y, B-Y are brought to a time base compression, and also, the signal R-Y and the signal B-Y are delayed by 1H and 1.5H, respectively, and they are recorded in an optical disk 13. At the time of reproduction, the signal Y is reproduced by a head 8, stored in a memory 16, and also, read out of the memory 16 by correcting a variation by a time base variation detecting part 19b, and the reproduced Y is outputted through a 1/2H delaying circuit 20. Also, the color difference signals R-Y, B-Y are stored in a memory 24, and also, signal switching parts 19a, 19c are switched, and said signals are reproduced by executing a time base expansion and a delay by a time base expander 26 through the detecting part 1b. Accordingly, the detecting part 19b can be used in common, and the cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disc recording and reproducing apparatus that divides information and converts it into two signals, and records and reproduces the signals on a disc using each dedicated head.

[Conventional technology]

First, a conventional technique for an optical disc recording/reproducing device will be explained. The optical disc has a guide groove provided on an arcuate acrylic base plate, a Terrell (Tg) compound film is attached to the surface on the groove side, and the ■ is provided in a spiral shape or in the same circular shape. Then, a laser beam guided from an optical head is irradiated onto the groove, and the heat of the laser beam locally changes the reflectance of the Terrell compound film on the guide groove, thereby recording video information, etc. There is known an optical disc recording/reproducing device that detects changes in reflectance using a weaker laser beam and reproduces the recorded information.

In addition, in recent years, in order to obtain high-quality images on any small disk with a diameter of 20 cm, the recorded information is divided into parts, and a dedicated optical head is used for each of the divided pieces of information. A configuration is adopted in which recording is performed sequentially from the middle circumference of a wide 10,000 Y disk to the outside, and from the inside to the middle circumference of the disk with a narrow side. In this Ha,
A luminance signal is used as the wide band, and a color difference signal (CI multiplied signal Q@ signal or RY signal and BY signal) is used as the narrow band. In particular, for color difference signals, the time axis is compressed during recording, and the time axis is expanded during playback.

Furthermore, in order to correct the time axis fluctuations that occur mainly due to eccentricity caused by positional deviation when attaching arc-shaped acrylic, a horizontal synchronization signal or a burst signal as a synchronization signal is added to the recording signal. Then, each time axis variation detection unit detects a time axis variation signal from the synchronization signal of each reproduction signal, and inputs the detected signal to each time axis variation correction device to adjust the time axis of each reproduction signal. Fluctuations are being corrected.

In addition, as related to the above-mentioned conventional technology, for example,
Japanese Patent Application Laid-Open No. 57-118490 proposes a configuration in which video information is divided into a full brightness signal and a color difference signal, and recorded and reproduced on a recording tape using respective dedicated magnetic heads. In addition, in Japanese Patent Application Laid-Open No. 58-19797 (S), the video signal is divided into high frequency components and low frequency components.
A single pilot signal is simultaneously superimposed on both, and each is recorded on a magnetic disk by a dedicated magnetic head. A configuration has been proposed in which the time axis variation is detected by a time axis variation detection section and the time axis variation is corrected using the detection signal.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology uses X synchronization signals for each recorded information (recorded signal) for time axis fluctuation correction of reproduction I-100, and the superimposed synchronization signal is gained or lost almost simultaneously when time axis fluctuation is corrected. As for the time axis variation detecting section for detecting the time axis variation from the synchronization signal, two sets of almost identical ones are required, and there is a problem that they are not sequentially adjacent to each other.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a time axis variation detection unit that detects time axis fluctuations.
The purpose is to reduce costs by sharing the signal between two reproduced signals.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention is arranged in a transmission path from a conversion means for converting divided information into two signals to a time axis fluctuation correction means, and is provided to add information to each of the two signals. a phase difference setting means for setting a phase difference of one foot between the two signals so that the periods of the synchronization signals to be transmitted do not overlap with each other in time; and the two reproduction signals input to the time axis fluctuation correction means. Input the same signal to each
a first switching means that alternately outputs the signals from one output by switching a switch; and a first switching means that detects a time axis fluctuation of the output signal from the first switching means and outputs a detection signal corresponding to the time before the fluctuation. a time-opening 1llll fluctuation detection means for outputting;
a second switching means that inputs the detection signal and outputs the detection signal alternately from two outputs by switching a switch;
The same signal as the two reproduction signals input to the time axis fluctuation correction means is inputted to create Mg synchronized with the synchronization signal added to each, and the first and second switching means are controlled by the signal. a control means for controlling the switching timing of the switch in the second switching means, inputting the two detection signals outputted from the second switching means to the time axis fluctuation correction means, and controlling the switching timing of the second switch based on these detection signals. Phase difference cancellation for extracting the time axis fluctuations of each of the two reproduced signals, and canceling a constant phase difference between the two reproduced signals after the time axis fluctuation correction, which is set by the phase difference setting means. It is designed to provide a take-home pay.

[Effect]

MiJ phase difference setting means consisting of a fixed delay circuit provided in the transmission path, so that timings of synchronous parts of the two reproduced signals do not coincide with each other when input to the first switching means. do.

Further, the control means controls the reproduction of the two signals.
A pulse [9 is generated at a timing corresponding to the end of each synchronizing signal portion, and the pulse signal controls the first and second switching means through a flip-flop. Thereby, the first switching means inputs each reproduced signal to a set of time axis variation detection means (time axis variation detection unit) without destroying the synchronization signal portion of each reproduction signal, and also The switching means 2 distributes the detection signals obtained from the time axis fluctuation detection means in correspondence to each reproduction signal.

Further, the phase difference canceling means includes a fixed delay circuit for the phase difference, which is provided on the side of the signal with a phase lead among the two signals subjected to the time axis fluctuation correction, and corrects the phase difference to obtain a normal signal. Inform.

With the above configuration and operation, between the two signals,
The time axis variation detection means (time axis variation detection unit) can be shared.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a disc recording/reproducing apparatus as an embodiment of the present invention. Figure 1 CA) shows the configuration of the recording system, and Figure 1 CB)! shows the configuration of the playback system.

Further, FIG. 2 is a time chart showing the signal order of the main signals in FIG. 1. FIG. 2(A) shows the main signals during recording, and FIG. 2(CB) shows the main signals during reproduction.

At the time of recording, the configuration shown in Figure 1 (, 4) allows
A signal obtained by dividing the recorded video information into a luminance signal and two color difference signals is converted into two signals, a luminance signal and a color difference signal, and the same N'' signal is added to each signal, and each dedicated optical head drives an optical disc. to be recorded. Also, Figure 1 (,4)
The configuration shown in 1 is provided with a means for providing a phase difference between the two signals so that the timings of the added synchronizing signal portions do not overlap with each other.

In FIG. 1(A), Y is a luminance signal, R-Y and B-
Y is a color difference signal, C-5YNC is a value congruent M signal, Bμγ''
t is 2 cycles 8 of the frequency He 2 AfHz at the backhoe part of the # line erasing pedestal of each horizontal synchronization pulse.

Burst signal where part enters, 1 to 4 are mixers, 5 is 1/2
1,4H delay device with fixed delay of H (R: 1 horizontal period)
6.10 is an FM modulator, 7 and 11 are laser modulators, and 8.
12 is an optical head, 9 is a time axis compressor, and 13 is an optical disk.

Next, the operation of FIG. 1 (, ()) will be explained using FIG. 2 (, 4).

The signal order of the luminance signal Y is as shown in FIG. 2 (CA) for the input Y shown in FIG. The darkness at the beginning of YrL+1 is a horizontal erasure period. During this period, the horizontal M signal of the combined synchronization signal C-5YNC and the burst signals Bu and rst are added by mixers 1 and 2, respectively. Then, the recorded Y signal is inputted to the FM modulator 6, and the recorded Y signal is inputted to the FM modulator 6, and the recorded Y signal is
M modulated. The output of the FM modulator 6 is input to the laser modulator 7, which controls the laser current on and off according to the FM frequency, thereby turning the laser light on and off. The laser beam is guided by the optical head 8 to the guide track of the optical disk 130 and recorded thereon.

The signal order of the color difference signals R-Y and B-Y is shown in Figure 2 (,
4), and these signals are input to the time axis compressor 9.

The time axis compressor 9 compresses the input RY signal to 1.5H and delays the band compressed signal by 1H. It also compresses the input B-Y signal into a band δH, delays the band-compressed signal by 1.5B, and outputs a signal that is a mixture of the band-compressed R-YM signal and the B-Y signal. Then, from the end of the B-Y signal of the output signal of the time axis compressor 9, a composite synchronization signal C-5YNC' of the horizontal synchronization signal is generated, similar to the Teruto signal.
horizontal synchronizing signal and burst No. 100 Bu and rst are added by mixers 3 and 4, respectively. The added signal is the recording C shown in FIG. 2 (, 4), and the signal passes through the FM vibration modulator 10 and the laser modulator 11 and is recorded on the optical disk 13 by the optical head 12.

As described above, the timing of the synchronization signal added to the luminance signal Y and the color difference signals R-Y, B-Y becomes a phase difference of 5.1/2H due to the delay of the "'AH delay device in the luminance signal transmission path, and the synchronization The timing of the @ period (in this case, the horizontal erasing period) has a phase difference that does not change.

Therefore, the recorded YM signal in FIG. 2 (, 4) has a phase of ',7. B is progressing.

Next, at the time of reproduction, the recording Y 4% and recording C signals recorded on the optical disk 13 are reproduced by respective dedicated heads using the configuration shown in Figure 1 CB), and the time axis fluctuation of each signal is is corrected by each time axis fluctuation correction device. At this time, the time axis variation detection section is configured to be shared between the two signals. Furthermore, the configuration shown in FIG. 1 CB) includes means for correcting the phase difference in the time axis fluctuation detection section.

2 in Figure 1 CB), 14 and 22 are FM vias,
15 and 25 are A/D converters that convert analog signals into digital signals; 16 and 24 are memories that record digital signals according to read signals and output digital signals according to read signals; and 17, 27, and 28 are digital converters. D/A i converters 18 and 25 convert signals into analog signals, and a memory control unit 19α outputs input signals 11 and read signals of the memory 16.

19C is a signal switching unit, 19b is a memory control fMsIB,
25 is a time axis variation detection unit that outputs a signal for determining the timing of the convolution signal outputted from 1;
'/2H delay device to obtain 4H delay amount, 21α, 21b
2 is a time axis variation correction device, and 26 is a time axis expander.

Next, using the time chart in Figure 2 (CB), Figure 1 (CB) is used.
The operation of B) will be explained.

In FIG. 1 CB), first, the recorded Y information on the optical disk 13 is reproduced by the optical head 8, and then passed through the 1M demodulator 14 to demodulate the y*'ri code shown in FIG. 2 CB).

And the Y* times signal time axis fluctuation detection part! 21α A/D
The signal is input to the converter 15 and one input terminal of the signal switching section 19α, respectively. The lβ converter 15 converts the Y*sign into a digital signal.

The output of the A/D converter 15 is connected to the input of a memory 160, and in the memory 16, the output 1-1' of the A/D converter 15 is connected to the input signal from the memory control s18.
ff are sequentially recorded at determined memory addresses. Then, the memory 16 sequentially reads out and outputs the signals written into the memory 16 by the read signals from the memory control @18.12. At this time, since the readout signal generated from the memory control unit 18 is synchronized with the reference signal and has no time axis fluctuation, the time axis fluctuation is corrected by reading from the memory 16. Further, the Y* numeric signal at this time is output with a delay of 1H.

The output of the memory 16 is then connected to a torque converter 17, where the digital signal is converted into an analog signal. The output of the D/A converter 17 is input to the /E delay device 20, delayed by /2B, and output as a reproduced Y signal shown in Figure 2 (B).

On the other hand, the recorded C information on the optical disk 13 is recorded by the optical head 1
It is played from 2, and then goes back to FM'4 tuner 22,
The C* signal shown in FIG. 2(B) is demodulated. The signals are respectively input to the Φ converter 25 of the C* multiplied signal time axis fluctuation correction device 216 and the other input terminal of the signal switching 1i 119α described above. The output of the Φ converter 23 is connected to the input of a memory 240, and the memory 24 performs time axis variation correction in the same manner as the luminance signal described above, using a signal from the memory control s25. The output of the memory 24 is input to a time axis expander 26.

In the time axis expander 26, the R of C* polarization shown in Fig. 2 CB) is
-The YrL signal is delayed by 1H and the time axis is expanded, and the second
Outputs the reproduced RY name shown in Figure (73), and furthermore, outputs the C
*Delay the double signal B-YrL signal by about /H and expand the time axis to output the reproduced B-Y signal.

The reproduced RY signal output of the time axis expander 26 is connected to the input of the D/A converter 27, and the output of the 4-channel converter 27 outputs the reproduced RY signal of an analog signal. Further, the reproduced H-Y signal output of the time axis expander 26 is connected to the input of the Luther converter 28, and the reproduced B-Y signal of an analog signal is output from the output of the D/A converter 28.

Further, in the signal switching section 19α, the input Y* times signal C
*Switch the double signal, convert it into one signal having a synchronization signal part, and input it to the time axis fluctuation detection 819h. The time axis variation detecting section 19A detects a horizontal period signal (hereinafter referred to as a burst H signal) synchronized with the burst signal of the synchronous portion of the signal input from the signal switching section 19cL.

The burst H ratio signal detected in this way is then input to the signal switching section 19c, and there, by switching the switch, the luminance parsing +4 (11, signal (horizontal and a color difference burst H ratio signal (a horizontal period signal synchronized with the burst signal of the C* signal synchronization portion).

The luminance burst H ratio signal is input to the memory control unit 18,
The memory control unit 18 passes this brightness burst to H through a pLL circuit (not shown) and outputs a compliment signal for the memory 16. Further, the color difference burst B ratio signal is inputted to the memory control section 25, and the memory control section 25 outputs a scanning signal for the memory 24 from this color difference burst H ratio signal through a PLL1 path (not shown).

As explained above, playback 4g from optical head 8.12
Since the phase of the Y* and C* multiplied signals of the number is '/2H ahead of the C* multiplied signal, the /H delay device 20 causes the Y* multiplied signal//! By delaying by H, the phase difference of the C* multiplied signal is corrected to zero. Then, reproduction Y corresponding to the input Y, large input -Y, and input B-Y signals of FIG. 1(A), respectively,
Replay-Y and replay B-Y signals are obtained without phase difference. Further, as described above, the time axis variation detection section 19b is configured to be shared.

Next, FIG. 3 shows the signal switching section 19α shown in FIG. 1 (CB).
, C and a block diagram showing the detailed configuration of the time axis variation detection section 19b.

In FIG. 5, 29, 3 (S, 42 are synchronous separation circuits, 50.57.45 are self-gate circuits, 32, 39
is a clamp pulse generation circuit, 53.40 is a clamp circuit, and 54 is an SR flip 7ay circuit (hereinafter referred to as S-RF/
55 and 49 are changeover switch circuits, and 41 is a low-pass filter (hereinafter referred to as LpF).
, 44 is a burst H ratio signal generation circuit, 45 is a gate pulse generation circuit, 46 is a gate circuit, 47 is a band pass filter (hereinafter referred to as f&BpF), and 48 is a burst pulse generation circuit.

Further, FIG. 4 is a waveform diagram showing the signal waveforms of the main signals in FIG. 3.

Now, the operation shown in FIG. 3 will be explained using FIG. 4.

As mentioned above, the reproduced 1t,, Y* signal from the optical head 8 is approximately '/H ahead of the %1t2C* signal from the optical head 12. These signal waveforms are as shown in FIG. 4. They are input to the Y* times signal synchronization separation circuit 29 and the clamp circuit 33.The synchronization separation circuit 29 outputs a Y* times signal composite synchronization signal. , are input to the self-gate circuit 30 and the integrating circuit 31.

The self-gate circuit 30 outputs a waveform α of a signal synchronized with the rise of the horizontal synchronization signal, and inputs it to the clamp pulse generation circuit 52. Further, the Hσ record division circuit 31 detects the vertical synchronization @ sign of the composite synchronization signal and outputs a luminance vertical synchronization signal. This luminance vertical synchronization signal is then used as the memory control H! It is input to S18, and the recording address designation of message 16 is returned to its initial value. The clamp pulse generation circuit 62 includes:
The bgt type signal shown in FIG. 4, which is delayed for a certain period of time from the rise of the α-shaping shown in FIG.

The clamp circuit 33 clamps the pedestal level on the longer side of the burst signal during the Y* times signal horizontal erasing period shown in FIG. 4 at the High level of the waveform shown in FIG. As a result, y*
The double signal pedestal level is fixed at a constant voltage, and the DC fluctuation component is removed and output. This is done in order to ensure that the synchronization separation is performed correctly in the synchronization separation circuit 42, which will be described later. Next, the output of the clamp circuit 33 is input to one input of the switch 35. Said S@
The RF/F 54 is set at the high level of the b signal shown in FIG. 4, outputs the ga-type Eight signal shown in FIG.

On the other hand, the signal is input to a C* flaw signal clamp circuit 40 and a synchronous separation circuit 36 shown in FIG. 4, respectively. Synchronous separation circuit 36
outputs a composite synchronization signal and inputs it to the self-gate circuit 67 and the integration circuit 38.

The self-gate circuit 37 outputs a waveform of a signal synchronized with the falling edge of the horizontal synchronization signal of the composite synchronization signal, and inputs it to the clamp pulse generation circuit 39. Further, the integrating circuit 38 detects a vertical synchronizing signal of the composite synchronizing signal and outputs a color difference vertical direction fijJfM signal.

Then, this color difference vertical cycle signal is transmitted to the memory control section 25.
is input, and the recording address designation of the memory 24 is returned to its initial value. The clamp pulse generation circuit 59 outputs the rLH type signal shown in FIG. 4, which is delayed by a certain period of time from the rising edge of the ε waveform in FIG.
Input to the R terminal of 34.

The clamp circuit 40 clamps the burst signal length side Budestal level of the C* flaw signal horizontal erasing period shown in FIG. 4 at the H level of the waveform d in the figure. As a result, the C* flaw signal pedestal level is fixed at a constant voltage, and the DC fluctuation component is removed and output. This is the clamp circuit 56
Similarly, this is done to ensure that synchronous separation is performed correctly in the synchronous separation circuit 42 that operates. The output of the clamp circuit 40 is input to the other input of the switch circuit 35. The S@RF/Fsa is shown in FIG. 4d.
It is reset at the Bsh level of the signal, and the LO of the ε waveform in the same figure
Outputs W signal.

In the switch circuit 55, the Bsh level 19 of the waveform 1 in FIG.
・ Blocks the Y* signal and allows the C* flaw signal to pass.

If the effli type in the figure is at Low level, the opposite is true.
Pass the Y* signal and block the C* flaw signal. Therefore, the output of the switch circuit 35 has the ε waveform shown in FIG. 4, and since there is a phase difference between the Y* multiplied signal C*fault signal/H, it can pass through the switch circuit 35 without destroying each synchronizing signal portion.

The output of the switch circuit 35 is input to the LPF 41 and the gate circuit 46, which constitute the time axis variation detection section 19b, respectively. Lp7''41 passes only the horizontal synchronization signal and inputs its output signal to the synchronization separation circuit 42.The synchronization separation circuit 42 outputs the horizontal synchronization signal with the H interval of the waveform 1 in FIG. 43. The self-gate circuit 43 outputs the ε waveform in FIG. 4, which is a signal synchronized with the falling edge of the waveform 1 in FIG. wI45
and enter it.

The gate pulse generation circuit 45 generates a gate pulse signal for passing only the burst signal portion of the waveform shown in FIG. The gate circuit 46 allows the burst signal portion of the ε waveform to pass through according to the gate pulse signal, adds a DC level equivalent to the DC level of the burst signal portion during other periods, and outputs a fourth waveform. Enter. BPFd7 improves the S/N of the h-waveform burst signal and inputs it to the burst pulse generation circuit 48. The burst noxle generation circuit 48 converts the h-waveform burst signal into a pulse waveform, outputs the ε waveform in the figure, and bursts R(
It is input to the other human input terminal of the llS signal generation circuit 44.

The burst H ratio signal generation circuit 44 is illustrated in m4! For one period from the timing of the rising edge of the waveform (period until approximately the falling edge of the first pulse of the continuous pulses of the ε waveform), the output of the ε waveform is blocked, and only the last pulse of the continuous pulses of the ε waveform is output. It is output as an ε waveform in FIG. 4 and input to the switch circuit 49.

The switch circuit 49 is switched by the ε waveform shown in FIG. 4, and when the ε waveform is at the Low level, the waveform becomes H.
1tBL type is obtained at high level. The kl shape is Y
*This is a flaw signal burst H ratio signal, that is, a luminance burst H ratio signal, which is input to the memory control unit 18 in FIG. , tg type is a C*flaw signal burst H ratio signal, that is, a color difference) and a burst H conversion signal, and is shown in Fig. 1 (B
) is inputted to the memory control unit 25 K, and becomes a pace signal for the sowing pulse timing of the memory 24.

As described above, the y*4g number, C*flaw signal parse)4 ratio multiple number, which corresponds to the Y*flaw signal C*flaw signal time axis fluctuation detection signal, is detected by one set of time axis fluctuation detection units 19b. In order to do this, signal switching sections 19α and 19C having switch circuits 55 and 49 are provided on the input and output sides of the time axis vibration detection section 19b. Further, the switch circuits 55 and 49 are controlled by a clamp pulse of a signal delayed from the reproduction horizontal synchronization signal of each signal, and the clamp pulse is generated near the end of the synchronization signal period. For this purpose, the synchronization signal portion of each signal can be input to the time axis variation detection section 19b in a time-division manner by the switch circuit 35. The clamp pulse corresponds to a signal synchronized with the synchronization signal of each reproduction signal described above. Therefore, one set of time variation detection unit 1
9b, it is possible to detect time axis fluctuations of the two signals Y*flaw signal C* polarization.

Here, the time axis fluctuation waveforms of the reproduced luminance signal and color difference signal appear to be approximately in phase because they are largely due to the eccentricity of the optical disk 13 and because recording is simultaneously performed on the same optical disk 16.

Therefore, the timing of the synchronization signal period of each reproduction signal is different depending on the amount of time axis fluctuation.

In addition, as for the amount of phase difference between the luminance signal and the color difference signal input to the signal switching s19α, since only the synchronization signal portion of each reproduced signal is required in the time axis variation detection unit 19b, the synchronization signal is subdivided into the time axis variation detection unit 19b. It is acceptable as long as it is not destroyed by the switching operation of the switch circuits 55 and 49 provided on the exit side of 19h. That is, the phase difference may be such that the synchronization signal period of each reproduced signal does not repeat one time.

If the phase difference is different from this example and is other than H, then 25
.

In order to prevent the third cause, the self-gate circuit 45, from malfunctioning due to noise, a means is added in which the self-gate time of the self-gate circuit 43 can be cut in advance by the output pulse number 1M of the self-gate circuit 60 and the self-gate circuit 37. That's good.

Further, in this embodiment, the phase difference is obtained by the /H delay device 5 during recording, but instead, a 16H delay device is provided on the front side of the input of the time axis fluctuation correction device 21α, 21b of the reproduced ml.
Even if you try to obtain a phase difference, the
The operations of the time axis variation detection section 19h are performed without any change.

In addition, in this implementation, the phase of the Y * flaw signal C * flaw signal also leads, but conversely, when the phase is made to lead than the C * flaw signal Y * Tsukuda, C *It is a good idea to use a delay circuit to correct the difference as much as it advances after the time expansion of the flaw signal.

Furthermore, the clamp circuits 53 and 40 before the switch circuit 35 in this embodiment are for preventing DC level fluctuations of the input signal, as described above, and are used in the Φ converters 15 and 25 described above. 24.

It's okay to have one.

In addition, when a magnetic disk other than an optical disk is used, and time axis fluctuation correction is performed using a charge delay system CC other than a memory.
The present invention is also applicable to cases where a CD) or the like is used.

〔Effect of the invention〕

In the present invention, during transmission failure from the means for converting into divided 2' signals to the time axis fluctuation detection section, the timings of the synchronization signal periods added to the two signals are made to be different from each other by 1jL. There can be a superior phase difference between the two signals, and therefore, the reproduced two signals are
The synchronization signal subdivisions of the two signals can be time-divisionally input to the time-base variation detection section, and the time-base variation detection signals obtained by the time-base variation detection section can be respectively outputted in a time-division manner.

Then, it is possible to correct the time axis fluctuation of the two reproduced signals using the detection signal.

As described above, according to the present invention, it is possible to share one set of time axis variation detection units between two signals, and it is effective in being economical.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a disk recording and reproducing apparatus as an embodiment of the present invention, FIG. 2 is a time chart showing the signal order of the first main signal, and FIG. 3 is a signal switching section and time chart of FIG. 1. FIG. 4 is a block diagram showing the configuration of axis fluctuation inspection, and FIG. 4 is a waveform diagram showing signal shaping of the main signals shown in FIG. 3. 5.20.../2B delay device 21α, 21b... time axis fluctuation correction device 19a, 1
9C...Signal switching section 19b...Time axis fluctuation detection section

Claims (1)

[Claims] 1. Conversion means for converting divided information into two signals, and addition means for adding a synchronization signal to each of the converted signals;
A recording/reproducing head for recording or reproducing the two signals to which a synchronization signal is added at different positions on the disk, and correcting time axis fluctuations of each of the two reproduction signals reproduced by the recording/reproducing head. In a disk recording/reproducing apparatus having a time axis variation correction means, a period of a synchronization signal arranged in a transmission path from the conversion means to the time axis variation correction means and added to each of the two signals. phase difference setting means for setting a certain phase difference between the two signals so that the signals do not overlap with each other in time;
A first input device that inputs the same signals as the two reproduced signals that are input to the time axis fluctuation correction means, and outputs those signals alternately from one output by switching a switch.
a switching means, a time axis variation detection means for detecting a time axis variation of the output signal from the first switching means and outputting a detection signal according to the amount of variation, and inputting the detection signal to switch the switch. a second switching means that alternately outputs the detection signal from two outputs; and a synchronization signal that outputs the same signal as the two reproduction signals input to the time axis fluctuation correction means and is added to each of the two reproduction signals. and control means for generating a signal synchronized with the switching means and controlling switching timing of the switches in the first and second switching means using the signal, and controlling the two detection signals output from the second switching means. input to the time axis fluctuation correction means, respectively correct the time axis fluctuations of the two reproduction signals based on the detection signals, and the phase difference setting means for the two reproduction signals after the time axis fluctuation correction. 1. A disk recording/reproducing apparatus characterized by comprising phase difference canceling means for canceling a certain phase difference between the two provided by the disc.