JPS6013368A - Reproducing device of rotary recording medium - Google Patents

Abstract

PURPOSE:To follow and scan a reproducing scanner precisely on a main track by switching the detecting outputs of the 1st and the 2nd reference signals to two input terminals of a comparator easily and stably every rotational period. CONSTITUTION:Main tracks t1, t2, t3,... on a rotary recording medium are recorded and formed every rotation of a disc 30 by numerous intermittent pits 31, tracking control reference signals fp1 (700KHz e.g.) and fp2 (500KHz e.g.) are alternately recorded every rotational period in an approximately intermediate part of the main tracks and a reference signal fp3 (300KHz) is recorded in a switching recording position 32 for the fp1 and fp2 as a timing pulse. An AGC circuit 44 is constituted so that the sum of respective reproducing levels of the fp1 and fp2 is always set up to a prescribed fixed level. A differential amplifier 54 compares the output signals of detecting circuits 52, 53 which are changed in accordance with the reproducing levels of the fp1, fp2 alternately outputted every rotational frequency, outputs a tracking error signal corresponding to the tracking shear direction and sheared deviation to control the tracking of a scanning stylus 40 stably by a closed loop.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a reproducing apparatus for a rotating recording medium, and in particular, a main information signal is recorded on a main track, and a first reference signal is recorded on one of the sub-tracks on both sides of the main track. from a rotating recording medium on which the signal is recorded, and on the other hand a second reference signal,
The present invention relates to a reproducing device that reproduces recorded edge main information signals at least at normal speed.

Prior Art Honda M has previously filed Patent Application No. M11R151-38809 (Japanese Unexamined Patent Publication No. 52-123205) and its divisional application (for example, Japanese Patent Application No. 52-25259 (Unexamined Japanese Patent Application No. 53-56001)).
etc.), the main information signal is continuously recorded on a spiral or concentric main track on a rotating recording medium as a change in geometrical shape using one of the two modulated beams. At the same time, a reference signal for tracking control is recorded at a substantially intermediate portion between each track center line of this main track (hereinafter referred to as a substantially intermediate portion between each rack 1 and b) using the other modulated beam, We proposed a method to reproduce this. In addition, the racking operation can be performed stably, and especially when applied to a scanning needle regeneration type rotating recording medium, the need for needle guide filling can be eliminated. It also has the advantage of being able to perform

Problems to be Solved by the Invention However, in the reproduction method proposed above, when reproducing a rotating recording medium on which a plurality of tracking control reference signals are sequentially switched for each rotation period of the rotating recording medium. Unless the switching recording position is accurately detected during reproduction, stable special reproduction may not be possible, and the racking control operation may not be performed even more stably.

Therefore, the present invention is directed to the first aspect. When reproducing a rotating recording medium in which a third reference signal is recorded at the switching position of the second tracking control reference signal every rotation, discrimination between the first and second tracking control reference signals in the reproduced signal is performed. Output 1~
Both transmission paths to the two input ends of the comparator circuit of the racking sabot circuit are connected to one another based on the detected output of the third reference signal.
A reproducing apparatus for a rotating recording medium that solves the above problems by reproducing the recorded edge main information signal of the main track while causing the reproducing scanner to perform follow-up scanning on the main track by switching at each rotation period. The purpose is to provide.

Means for Solving the Problems The present invention distinguishes first and second reference signals reproduced from sub-tracks on both sides of the main track being scanned by the reproducing scanner from among the reproduced signals of the reproducing scanner. At the same time, the third reference signal is discriminated and separated, and based on the detected output signal of the separated third reference signal. Both transmission lines to the two input terminals of the comparator circuit are switched every rotation period, and the reproducing scanner is caused to follow-scan the main track based on the error signal obtained from the comparator circuit. The apparatus is constructed to reproduce the recorded edge main information signal of the main track at least at a normal speed, and one embodiment thereof will be described below with reference to the drawings.

Embodiment FIG. 1 is a block system diagram of an example of a recording system of a rotating recording medium (hereinafter explained using a disk as an example) to be reproduced by a reproduction apparatus according to the present invention, and FIGS. 2(A) to (D) > respectively indicate signal waveform diagrams for explaining the operation in Fig. 1. In Fig. 1, a laser beam emitted from a laser light source 1 is partially reflected by a half mirror 2 and supplied to a light beam modulator @14. On the other hand, a part of the light is transmitted and further reflected by the reflecting mirror 3, and then supplied to the light beam modulator 6. On the other hand, the input terminal 4
The color video signal to be recorded received from
The vertical synchronizing pulse 25 is shown as a unit in (C) of the same figure, and the horizontal synchronizing pulse 26 is shown as a unit in FIG. The FM wave is applied as a modulation signal to the light beam modulator 6, where it modulates either of the lasers. As a result, the first modulated light beam modulated according to the FM6 signal is extracted from the device 6. This first modulated light beam is reflected by the reflecting mirror 1G, transmitted through the polarization brism 17, and further transmitted through the anti-OA#l11
8 and enters the objective lens 19.
Here, the modulated light beam of the main information signal is focused and then a disk-shaped recording source such as glass? The light is focused and focused on the photosensitive material 21 coated on the surface of the photosensitive material 11120, and the subsequent photoresist I
Through Z8 processing, a spiral or concentric main track is recorded by changing the geometric shape.

On the other hand, input terminal 7. oscillator 10°11.1 from fl, 9
A switching pulse is applied to 2, for example, its positive electrode t
The oscillation operation is performed during the /I period, and the oscillation operation is stopped during the negative polarity period.

Oscillators 10, 11 and 12, during their oscillation operation, [11
-Frequency [ρ1 (ρ [e.g. 700kHz7), fp
2 (e.g. '+00kH7) and fp3 (e.g. 3
00kl-IZ) respectively. Here, the input switching pulse of the input terminal 7°8 is, for example, when recording a video signal of 2 frames \\ from one rotation of the recording master 20, as shown in FIG. 2 (△) and (C). The vertical sync pulse 25 is divided into 111f from the color video signal to be
The J pulse shown in (13) in the same figure with a period of 1/2 frames is obtained by counting down 1//1, and the sync signal part is separated from the input video signal, and the 26 pulses in the same figure (C) are obtained. ”
The horizontal synchronizing pulse is separated and output every period (I N < 1-1, horizontal scanning period), and its pulse width is determined by the horizontal blanking period (hereinafter 1-1.8) of the color video signal to be recorded.
(abbreviated as LK) are used alternately every two frame periods. Note that the reference signals rp+ and fp2 for racking control from 1 to 27 are shown in FIG. 2(C).
The above pulse width is selected so as not to affect the color burst signal shown in . As a result, the oscillator 10 generates the first 1-racking control reference signal rp.
I is output for two frame periods (1/15 seconds) with the time phase relationship shown in FIGS. The reference signal fp2 is output for two frame periods with the time phase relationship shown in FIG.
1. rP2 is output alternately every two frames.

Here, a third reference signal fp3 is output from the oscillator 12J at the same time as the index pulse at 1 o'clock and at 1 o'clock, corresponding to the switching position of the reference signals rPI and rP2. In this case, if the main information signal to be recorded is a video signal, the vertical blanking period (hereinafter referred to as V-BLK) is required in addition to special playback such as static image playback or speed playback. ), the reference signal fP3 is inserted and recorded in the V and BI- portions. FIG. 3(A) shows the V and BLK portions of the recorded video signal, from the vertical synchronizing pulse to the first horizontal brightening pulse after the equalizing pulse, there are J3 and 2 to 31-1 as shown by 28a on the white side.
It is conceivable that an appropriate pulse for a period of time is recorded as the signal @fP3. However, when playing a still image 1-1 or in slow motion, the scanning needle is signaled [ρ3 to J:], which causes the kickback operation. Specify 1 - Place the scanning needle on the rack - 〇 - Stability 1. ! i! 7, with some hunting, wait for the response of the scanning sword's 1~4gum 1bing mechanism! Due to the above relationship, there may be some noise on the screen due to the effects of the kickback. Therefore, in order to completely insert the kickback into V and Bl-, the switching operation during signal recording and playback should be performed just before the end of the video signal. Therefore, in this case, J2 is necessary. may be inserted and recorded in the recorded video signal at the timing position shown at 28b in FIG. 3(A).

However, the present invention is not limited to tracking and reproducing a disc on which a video signal is recorded, but also on tracking and reproducing a disc on which only an audio signal is recorded in FM or PCM with a sufficiently wide dynamic range and high quality. You can play long-time or multi-channel discs on the same playback device by simply adding an adapter to play those video discs and audio discs.
- It can also be used for the purpose of playing discs interchangeably; in such a case, the audio information does not include the horizontal 10- or vertical sync pulse information, so fP3 is used as the third 28a or 28 in figure (A)
Since it is not appropriate to record with the signal waveform shown in 1) from the viewpoint of compatibility, it is desirable to record fP3 as follows.

■ The fp3 is oscillated for an appropriate period at a predetermined phase position corresponding to one revolution of the recording medium, and is superimposed at an appropriate level on a predetermined portion of the main information signal by a synthesis circuit shown as 2/I in Fig. 1, thereby producing the first modulated light. Recording is performed on the same track as the main tracks 1 to 1 by the beam.

■ fp3 together with the fPI and fP2 in Figure 2 (D)
, as shown in FIG. 3 (A>), are supplied to the synthesizing circuit 13 for a predetermined period of time, and synthesized in time series, and recorded by a second modulated light beam, which will be described later.

Among the above methods (1) and (2), method (2) is more preferable than method (2) in terms of performing stable tracking servo operation. That is, during reproduction, which will be described later, the reference signal fP3 is differentially reproduced and the reproduced reference signal fP1. fP
It is essential to switch the tracking control polarity of No. 2 every rotation period of the disk, and therefore, stable reproduction of the reference signal fp3 is essential in order to stably perform tracking control.

On the other hand, during tracking control in which the pickup reproduction scanner is electronically controlled to follow the main track, ideally it is preferable to make it follow the center line of the main track.
In reality, tracking control is performed while slightly meandering along the main track.

Therefore, even if the reproducing scanner follows the main track while meandering, the main track receives the reference signal [P3].
If this is recorded, the fluctuation in the level of the reproduced reference signal fp3 is smaller, and therefore tracking control can be performed more stably.

However, it goes without saying that tracking control can be performed even when the reference signal fp3 is recorded on the sub-track and reproduced.

- As an example, to explain method (■), synthesis circuit 1
The output signal of No. 3 is applied as a modulation signal to the optical beam modulator 1/I, where it is converted into an optical modulation wave, and then transmitted to a second modulated optical beam whose brightness (beam light amount) is passed through an optical filter 15. The light of the first modulated light beam □□□J: is suitably attenuated and guided to the polarizing prism 17, where its polarization plane is 90 degrees with the polarization plane of the first modulated light beam. '
be shifted. ”-The output signal of the synthesis circuit 13 is as shown in FIG.
It will be as shown in C) or (D). Here, in Figure 3 (C
), fp3 is in the switching position of fP I and fP2.
, a predetermined 1 with a sampling period of H units similar to fP2.
The waveform is shown when inserted and recorded as an intermittent oscillation pulse of 2 to 3 H periods corresponding to the pulse width of a one-cycle pulse.

Further, (D) in the same figure shows a waveform when fp3 is continuously recorded for a predetermined width period of 2H-31-1.

Figure 3 (B) shows 11 points synchronized in phase with the video signal to be recorded.
When recording only periodic pulses or audio information, it indicates a reference pulse for finely controlling the rotation of the recording master 20, and when recording at least a video signal, the period indicated by 29 corresponds to the vertical blanking period of the video signal. do. This H-period pulse is the reference signal fρIn fp2. fp3 and FIG. 3 (B), (C) 13- or (D) respectively show a clear phase relationship.

In addition, rp+ is also added to the part where fP3 is inserted.

fP2 may be sequentially and alternately inserted and arranged. However, since the reference signal rp3 is recorded, it is about 3 to 4H fP1.
Even if fP2 is missing, it actually does not cause any trouble to the tracking servo operation.

The second modulated light beam that has passed through the polarizing prism 17 passes through a reflecting mirror 18 and an objective lens 19 at the same time as the first modulated light beam, and then onto a photosensitive material 21 on a recording master 20 that is being rotated synchronously. is irradiated while moving in the radial direction at a predetermined pitch, and a subsequent development process forms, for example, a spiral sub-rack as a change in geometrical shape. At this time, the incident optical path of the second modulated light beam to the objective lens 19 is adjusted by the polarizing prism 17 with respect to the first modulated light beam. For the 11-racks to be recorded, the tracks are spaced approximately 1/2 track pitch (here, 1-rack pitch refers to the distance in the 14-track width direction between the circular scanning center lines of adjacent 1-racks). Add 1-lac to fiL-forming acid. Further, even in the case of a disc to which this sharp scanning needle type signal reading format is applied, the scanning 11 in-shape recess is not formed.

FIG. 4 shows a frequency spectrum of an example of a signal recorded by the recording system shown in FIG. I, II and ■ are NT
The shift frequency band (7 to 10M1-IZ) of the carrier wave in the first modulated wave recorded on the main track, which is frequency-modulated on the first carrier wave with the SC system color video signal and audio signal, and the lower sideband (2 , 5~7M1-1z> and upper sideband (10~
15MHz> is indicated respectively. The frequencies of the reference signals fp + , fp 2 , and fp 3 are selected in a frequency band lower than this lower sideband (2).

a3. In Fig. 1, if it is inconvenient to divide the laser light source 1 into two beams due to the beam power etc., another laser light source indicated by the broken line 22 is newly prepared, and the light beam intensity and modulation degree are adjusted. etc., to the first modulated light beam, and the output light beam is passed through the reflecting mirror 23.
Even if the configuration is such that the light beam is supplied to the light beam modulator 14 contrary to the above, it is not possible.

In this case, the emitted light beam of the laser light source 1 is supplied only to the light beam modulator 6.

Further, in the case where a color video signal is recorded as the main information signal, each of the reference signals may be obtained by frequency-downgrading the color subcarrier.

Furthermore, instead of recording using a light beam, two electron beams
Even if I try to record it with a heavy beam, it's still not possible.

Each of the track patterns recorded on the cutting master disc or the pressed rotary recording medium by the recording system shown in FIG. 1 results as shown in FIGS. 5(A) to 5(D). rPl, fP2° and fP3 are recorded aligned in the inner center direction of the disk 30, which is an example of a rotating recording medium.

FIG. 5(B) is an enlarged view of a part of the circular area of the disk 30 shown in FIG. 5(A), without showing the track pan of the first embodiment. i3゜... is the 1st, 2nd, 3rd, etc. main track recorded for one rotation of the disk 30 by countless intermittent pitches 1 to 31, and the distance between each main track is fp+ approximately in the middle part,
The tracking control reference offset of fp2 is recorded alternately in one rotation period by intermittent bits having a depth shallower than the pit depth of the main track, and the third reference signal fP3 is as shown by the broken line <fp+, fp2. It is recorded at the switching recording position 32 as a timing pulse (index pulse). When the main information signal is at least the video signal J:, fp+, fp2 are recorded in the horizontal blanking period shown at 33 in FIG. 5(B), and fP, is recorded in the V, BIK portion. is as described above.

FIG. 5(C) is a further enlarged view of the main part of FIG. 5(B), and shows the track pitch indicated by 34 (for example, 2.8z1
m), bit width (track width: e.g. 2.6t1m
) A first embodiment in which a sub-track with a bit width of 36 (for example, 1.2 μm) is recorded approximately in the middle between each of the 35 main tracks, with an overlap portion of 37.37' with the main track. The track pattern is shown below. When reproducing a disc with this track pattern, a single scanner reproduces the main information signal from the main track and at the same time reproduces the rp.
+, fp2 can always be compared as the analog fifth, and therefore a stable servo loop can be constructed in which this output level maintains a balanced state. Also, when overlapping recording of the sub 1-rack on the main track and reference signal is performed. Since recording can be formed in extremely close contact with each other, it has an advantageous feature in terms of increasing the recording density.

In Fig. 5 (D>), the track pitch 34 is 2.B (1 m), which is the same as in Fig. 5 (C), but the bit width of the main track is 38.
The main 1-rack is recorded with a track width of 2.8 .mu.m so as to match the track pitch 34 and eliminate blank areas between each main track, and a bit width 39 of, for example, 1. A partially enlarged plan view of a track pattern of a second embodiment in which sub-tracks of 0 μm are recorded and formed so as to overlap with main tracks. When this track pattern is recorded, it is more advantageous to increase the signal reading sensitivity and the recording density of the information track.

Next, to explain the rotating recording medium reproducing apparatus according to the present invention, FIG. 6 shows a block system diagram of an embodiment of the rotating recording medium reproducing apparatus according to the present invention. A reproduction signal from the disk 30, which is read by the scanning needle 40 as a slight change in capacitance using a known technique, is supplied to a preamplifier/11 having a resonant circuit whose resonance frequency changes in accordance with the change in capacitance. After the signal has been converted to a desired level, it is divided into two parts, one of which is output to an output terminal 42J: a demodulator (not shown) to reproduce the main information signal, and the other is output to an output terminal 42J: a demodulator (not shown) to reproduce the main information signal. Main information signal recording band shown in ~
■J: Rimo 11 A where low frequency components are separated and filtered
The signal is supplied to the GC circuit 44. The low-pass filter 43 uses a reference signal fPl so that the AGC circuit 44 is not affected by the reproduction level, frequency characteristics, etc. of the main information signal in the reproduction signal.

It is designed to separate these reference signals from the main information signal so that only the required frequency components of fPl and fP3 are transmitted in one wave.

By the way, the reproduction signal of the preamplifier 41J is generated based on the radial position of the disk 30, subtle changes in the contact situation such as the surface of the disk 30 and the electrodes provided on the scanning needle 40, and the laminar movement of the scanning needle 40. The reproduction level changes due to dust adhesion to the surface, changing the loading of the disc, and subtle changes over time in the contact situation, etc., all of which involve the reference signal rp.

fpz, fpz also has fluctuations in playback level from time to time,
If this was directly converted into DC error power and applied to the drive mechanism of the scanning needle 40, the loop gain of the reel would always change by [, 1] as the playback signal changes by 1 novel, resulting in a stable tracking nervo. This will disturb the servo loop and cause mistracking.

Therefore, before discriminating and separating each of the reproduced reference signals and applying them to the differential amplifier, the ΔGC circuit 4/1 is provided to keep the reference signal level always at a predetermined level and to correct the change in the reproduced signal level. I have to. However, since the reproduction levels of the tracking control reference signals fρ+ and fpz change according to the tracking deviation, it is necessary to detect this change and perform tracking control. It is necessary to configure the system so that the sum of the respective reproduction levels always becomes a predetermined constant level.

The output signals of the circuit 44 are fPl, fPl and fP3
are simultaneously supplied to bandpass filters 45, 46 and 47, each having a center frequency of a steep passband. Output reproduction reference signal fp of bandpass filter 45.4.6, fp
2 are respectively shown in FIG. 7(A).

As shown in FIG. 5B, when the disc 30 is reproduced, each is continuously outputted, adjusted to a predetermined level by the variable resistors 48 and 49, and supplied to the polarity switching circuit 50. At least during normal reproduction, as shown in FIG. ) is applied from the input terminal 51 with a switching pulse generated based on the position 32 (V, BLK portion if the main information signal to be recorded is a video signal), and one rotation period of the disk 30 is generated. rp+ and fpz switching is performed every time. Here, as mentioned above, the disk rotation speed is 900 rpm.
- Therefore, since two frames of video signals destined for the rotation of the diode 291 are recorded, the polarity switching circuit 50 sends a signal to the detection circuit 52 by a polarity reversal switching pulse every two frames (1/15 seconds) as shown in Fig. 7 (C ) and is supplied to the detection circuit 53 as a signal shown in (D) of the figure.

Therefore, the above switching pulse is applied to the disk 30.
can be obtained from the reference signal fP3 recorded corresponding to the switching recording position of fP'l+fP2. That is, FIG. 7(E) separated by the bandpass filter 47
The third reference signal fP3 (not shown) is supplied to the detection circuit 67, where it is shaped into a waveform that is not affected by noise, etc., and then applied to the flip 70 knob 68 to trigger it. The output of this flip-flop 68 is applied to the input terminal 51 from the output terminal 69.

In addition, in this case, scan! In order to prevent the effects of signal loss, noise, etc. from 140 and to obtain a more stable and reliable switching pulse at terminal 69, a flywheel oscillator such as a free-running oscillator at 15Hz, or a It is desirable to apply an FC circuit, etc. to the 47.H construction [1]C circuit 68 in order to obtain a similar IQ (2).

Detection circuits 52 and 53 convert the input reference signals into DC voltages and supply them to respective input terminals of differential amplifier 54. The differential amplifier 54 outputs −C according to the reproduction of fPl and fpz.
Compare and contrast the output signals 23 of the detection circuits 52 and 53 to output a racking error signal of 1 to racking error according to the direction of the rack shift and the maximum shift deviation, and adjust the loop gain of the entire servo loop. Via the resistor 55, the signal is supplied to a proportional compensation circuit 56 and a differential compensation circuit 57.The signals which have been compensated with a predetermined characteristic I11 by these compensation circuits 56 and 57 have their respective gains 1', 7 is supplied to the control power amplifier 60 via variable resistors 58 and 59 for adjusting the voltage.
After the power is increased to a predetermined level, it is applied from the output terminal 61 to the moving element of scanning t+-/10, and the scanning side 40 can be stably tracked in a closed loop.

- The present applicant first proposed a cantilever in Japanese Patent Application No. 51-1232 n 5 as the moving machine 474 element described in 1982 (f: August 20, 1982). When this device is applied, it is possible to perform stable and high viscosity control from 1 to 1. In other words, one end of the scanning r, l/IO is fixed to the C bracket 1-61 via the gunpa 63. A permanent magnet 65 is fixed to the free end of the AT cantilever 62, extends in the same direction as the longitudinal direction of the cantilever 62, and is magnetized in the thickness direction. The campreper 62 is the driving displacement μ in the direction perpendicular to the track scanning direction.

The scanning side/IO is accordingly controlled in a transcribing manner.

Incidentally, the scanning 117'IO was previously proposed by the present applicant in Japanese Patent Application No. 127767/1983, for example! As shown in FIG. 8, it is more desirable to use a needle structure in which the width of the b electrode does not change as wear progresses, from the standpoint of scanning time and surface space.

FIG. 9 shows a specific circuit of an example of the GC circuit/17'I. The output signal of the low-pass filter 43 is sent from the input terminal 71 to the control amplifier 72. The detection circuit 7 passes through the amplifier 73 in sequence.
5 is envelope-detected and converted into a DC component, which is then amplified by a DC amplifier 76 and converted into a DC voltage according to the level of the reproduction R. After being further superimposed with the DC level from the 1'! ΔGG
The output is directed to output terminal 74.

Next, go to 〇〇 Figure 10 (A) for a modification of the circuit configuration.
This will be explained together with (B). Same figure (△).

(13) The same parts as in FIGS. 6 and 9 are designated by the same reference numerals, and their explanations will be omitted. J to bandpass filter:
Discrimination again [Sita1~Racking control reference signal fρ++
Detecting the level of fP2 and calculating ΔGG for each output is the result of the relationship between the elasticity and rigidity of the cantilever 62 and the applied control power during the control operation of the controller 62. In the equilibrium situation, etc.
The reproduction level of l, fpz is varied in conjunction with the tracking control operation, ft)+.

The relative value of fPz] is not always constant;
Detecting the ΔGG control voltage from the individual levels of ρl+rρ2 is fundamentally contradictory to the operation of the Ribo control 611. That is, the reference signal fPl is determined by the mechanical displacement of the cantilever 62.

The reproduction level during the tracking operation of fP2 is not always in a balanced state, and as a result, the reproduction levels of fPl and fpz are not always kept at the same level. Therefore, holding each of the reference signals fPl and fpz at a predetermined level by the GC circuit means that the servo control operation
As a result, the specified function cannot be performed. Therefore, the configuration of the GC circuit applied to the playback device is such that each of the reference signals fp+ and fpz is at a predetermined level 4Z at the input part of the tracking ribo circuit, that is, the GC circuit is
As mentioned above, the control voltage for the control is at least 26-. generated at the input of the servo circuit where rp2 is present at the same time, or the reproduced reference signal rP
1. If the configuration is such that the signal is generated after separating the reproduced reference signal fP1.rP2, the reproduced reference signal fP1.rP2.
The configuration may be such that the voltage of the sum of fP2 is used as the reference voltage. Note that since the output of the differential amplifier 54 becomes a DC voltage as a tracking error signal, the output of the differential amplifier 54
An AGC circuit cannot be inserted for the output of
It is clear that even a reference voltage for control cannot be generated.

In FIG. 10(A), the output DC voltages of the detection circuits 52 and 53 are added by resistors 78 and 79, and then appropriately level-enhanced by the DC error amplifier 80 and sent to the A G C control amplifier 72 as a gain control voltage. Feedback is applied. As a result, the reproduced reference signal f is controlled by a single AGC control circuit.
P1. The level of the sum of fP2 can always be kept approximately constant.

FIG. 10(B) is an example in which two AGC circuits 82 and 83 are used, and the reproduced reference signal fp+ is output from the low-pass filter 43.
, fp2, and the reproduction level in which only the band region of the racking control reference signal is filtered is detected and taken out, and the DC voltage is further amplified by an amplifier 88 and sent to the AGC circuit 82 as a control voltage. 83 simultaneously. In addition, an AGC operation similar to that shown in FIG. 6 can be performed. In this case, the AGC circuits 82 and 83 are configured to perform AGC operation from a DC level.

In the configuration of the AGC circuit of the playback device described above, as described above, a single frequency that is about one order of magnitude lower than the carrier wave of the main information signal is applied to the reference signal combined with racking control. The recording wavelength is short (in the example, about 1.4 μm at the outer circumference and about 0.6 μm at the inner circumference). However, since the recording wavelength of the tracking control reference signal is an order of magnitude longer than that of the main information signal, the reproduction level is slightly unstable. ,
Stable output can be obtained. Furthermore, in order to prevent the tracking control reference signal from interfering with the main information signal, especially the audio signal, the recording level of the tracking control reference signal is attenuated by about -15 with respect to the main information signal. There is.

However, the frequency domain of both the main information signal and the reference signal (
Due to the difference in frequency characteristics depending on the wavelength), the disc radial position of the main information signal and the reference signal, and the reproduction level change situations caused by the various signal reading situations do not necessarily correspond.

Therefore, the reference signal to be applied to the tracking servo needs to be applied to the AGC circuit while being maintained at a predetermined level at all times as described above.
Either the main information signal is output and the entire area is controlled, or the gain control reference voltage for AGC control is detected from the reproduction level that includes at least the carrier wave area of the main information signal. The desired purpose cannot be achieved. However, in the above servo configuration, only the tracking system 29 in the low frequency region where the main information signal is not included and the region where the combined reference signal is recorded is transmitted to the preamplifier 41.
fPl, which serves as a reference signal for racking control;
By configuring the GC circuit as described above so as to generate the signal from the filtered outputs of both fP2, the intended purpose can be achieved satisfactorily.

Next, FIGS. 5(B), 6, and 11(A) to 11(D) show the operation of the playback device when performing still image playback or slow motion playback of the rotating recording medium according to the present invention.
I will explain it together. First, to explain the case of still image reproduction, for example, when obtaining a still image by continuously reproducing only track t2 shown in FIG. the last stop)
32 (recording position of rp3 explained in FIG. 3), t
2, and the track t for one rotation period of the disk 30 is started.
2, and when the position indicated by 12' reaches the position indicated by 32 again, if the control polarity remains the same as that of track t2 and the switching operation of the polarity switching circuit 50 is stopped, the running will not proceed. -30- Scan it When 40 passes the position 32 again, it scans the track 13 once again, but when it detects fPl and fP2, the tracking control polarity of fρ+ and rp2 to t2 and the track side remain unchanged. It is not possible to rack playback from 3 to 1, but it means jumping to rack 1 at t2 or 14 and scanning any 1~rack, and the I~rack that covers the scanning is t2. Therefore, continuous playback of only 12 is impossible.

Therefore, when reproducing an image in the first position, at the same time as the switching operation of the circuit 50 is stopped J1, an i-track pulse is applied to the 1-racking servo system at the switching position 32, and from the position 12' to the position 32, the i-track pulse is applied to the track t2. 10 to 11 to Ratsukupizji at the starting point position! I tried to do that.

For this purpose, the switching pulse from the output terminal 69 (or the output of the detection circuit 67) shown in FIG. A pulse (not shown in FIG. 11(B)) is output corresponding to the position 32 every frame period, and is used as a timing pulse (kick pulse) for the kick pack operation, for example, from the input terminal 70. It is applied to the differential compensation circuit 57. In actuality, the polarity of the kick pulse during still image playback is selected by taking into account the control polarity of the navigation system and the scanning r1 moving mechanism, and the polarity of the kick pulse is selected so that the jump deviation amount is exactly 11 to 1000 pitch. I decided to set the kick pulse amplitude and pulse width in advance.
Desired still images can be played back.

Also, when performing slow motion playback at an arbitrary speed ratio, for example, when playing slow motion at 1/7,
A kick pulse is applied to the input terminal 70 in connection with decelerating the transport speed of the disk 3o in the semi-longitudinal direction during the scan r140 to 1/7 of that during normal playback, and the kick pulse is applied to the input terminal 51.
The switching pulse applied during normal playback is reduced to 1/7
is counted down and applied to the input terminal 51. In other words, the switching pulse is counted down to 1/7 to become a pulse as shown in FIG.
1 is applied to the polarity switching circuit 50.

At the same time, a kick pulse as shown in FIG. 11(D) is applied to the input terminal 70 so that the scanning side 40 repeatedly reproduces the same track seven times.

This allows 1/7 slow motion playback.

A3: To advance the scanning side 40 to the next track after repeated reproduction a predetermined number of times, press fp+ at switching position 32.
, fp2, and the kickback pulse is stopped from being applied to the terminal 70. Furthermore, during fast motion reproduction, the kick pulse is polarized so as to kick the scanning needle 40 in the forward direction by 11 to rack pitches. In addition to the above, other special reproductions such as reverse reproduction and high-speed reproduction can also be performed as desired.

The above playback device has been described for the case where fP3 is inserted and recorded in the V and BIK portions of the waveforms shown in FIGS. 3(C) and (D) and is generated as a timing pulse during playback, but for example, V, BL33- to 2-31-1 period fP1. It is also possible to serve the purpose of fP3 by not recording fP2 and detecting and distinguishing the missing portion from other recorded portions during playback (for example, by passing fPl and fP2 through an integrating circuit).

Application example The track pattern of the disc to be played is as follows:
The present invention is not limited to those shown in FIGS. 5(B) to 5(D), and can also be applied to, for example, track patterns recorded so that adjacent main track and sub-track portions do not overlap.

Further, the reproducing pickup means for the disk 30 includes a capacitance detection type scanning needle I'1. The present invention is not limited to O, but may include a scanning needle having a transducer that converts mechanical vibrations into electrical signals, or means for reading signals based on the light intensity of laser reflected (or transmitted) light from semiconductor laser light emitting elements and disks. The present invention can be similarly applied to a disk player device of a signal reading device to which the well-known reproduction scanner is applied.

Further, the main information signal to be recorded is not limited to a video signal, but the present invention can also be applied to a rotating recording medium on which an audio signal is recorded as a high-quality, multi-V channel with a high dynamic range.

In addition, although the case where a single frequency is used for fp+ and fp2 has been described above, for example, a signal obtained by FMing an audio signal and continuously recording it is used as the reference signal fP1. It can be appropriated as fPz. Furthermore, the carrier color signal in the color video signal is frequency-converted to a low frequency band using a well-known technique, and is converted into a reference signal fP1. Modifications such as appropriating it to fPz are also possible.

In short, the reference signal only needs to be recorded and reproduced in a signal form that can at least be used for tracking control.

Effects As described above, according to the present invention, the third reference signal is recorded at the main or sub-track position corresponding to the switching recording position for each rotation period of the first and second reference signals recorded on the sub-track. Since the recorded rotating recording medium is reproduced, the first and second reference signals are
The transmission of the detection output of the reference signal to the two input terminals of the comparator circuit of the 1-racking 1-nervo circuit) can be easily and stably switched for each rotation period. In the tracking control operation, it is possible to accurately follow and scan over the main track, and with this configuration, the jr + raw main information signal of the main track can be stably obtained from the reproducing scanner at least at normal speed. Furthermore, since a kick pulse during special reproduction is generated from the third reference signal and applied to a predetermined part of the first herging sabot circuit, still images can be reproduced: slow [-
It has the advantage of being able to stably and freely perform special playback such as John playback.

[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, and Fig. 2 (Δ) to (r))
3 (Δ) to (D) are respectively signal waveform diagrams for explaining the operation of FIG. 1, FIG. 4 is a diagram showing an example of the frequency spectrum of the recording signal by the recording system shown in FIG. 1, and FIG. (Δ)～(
D) is a partially enlarged plan view of each track pattern of a rotating recording medium, and FIG. 6 is a block system diagram of an embodiment of the reproduction 'I[ of a rotating recording medium according to the present invention.
([) is a signal waveform diagram for explaining the operation in FIG. 6, and FIG. 8 is a diagram 1' showing an example of the scanning side shape previously proposed by the present applicant.
Fig. 9 is a specific circuit diagram of an example of the main part of Fig. 6, Fig. 10 (A>, (B) is a diagram showing each modification of the main part of Fig. 6, and Fig. 11 (A) ~(D) are signal waveform diagrams for explaining the operation of FIG. 6. 1.22... Laser light source, 4... Video signal input terminal, 6, 14... Light beam modulator, 10. 11゜1
2... Reference signal oscillator, 19... Objective lens, 20
...recording master, 30...disk, 40...scanning needle, /11...preamplifier, 43...low-pass filter, 44°82.83...A G C circuit, 45 .46
．． 47...Band filter, 50...Jii switching circuit, 51...Switching pulse input terminal, 52.
53.67...Detection circuit, 54...Differential amplifier, 6
2... Cantilever, 37- 67... Detection circuit, 68... Flip-flop, 7
0...Kick pulse input terminal. 38- 〈-Movie mo AK -449- ^ to ^ ^ Ku no QO Procedural amendment (method) July 2, 1980 Mr. Manabu Shiga, Commissioner of the Patent Office (Mr. Patent Office Examiner) 1. Indication of the case Showa 1959 Patent Application No. 44727 2, Title of Invention: Rotating Recording Medium Reproducing Apparatus 3, Amended Person's Patent Applicant Address: Kumo 221, 3-12 Morishuku-cho, Kanayō-ku, Yokohama-shi, Kanagawa Prefecture Name (432) ) Representative of Victor Japan Co., Ltd. Director Toninaga Shishi Michi - Department 4, Agent June 26, 1981 (Delivery date) 6. Column for a brief explanation of the drawings in the specification subject to amendment. 7. Contents of the Amendment In the 4th and 5th lines of page 37, 1. "Fig. 7...respectively" is amended to read "Fig. 7". 2-

Claims (1)

[Claims] (1) The main information signal is recorded by forming spiral or concentric main tracks, and the recording frequency range of the main information signal is The first one with different frequencies in the low frequency region
and a second reference signal for dragging control are sequentially switched every rotation period of the rotating recording medium to form a "C" sub-track and recorded, and a third reference signal is switched every rotation period of the rotating recording medium, and the third reference signal is switched over every rotation period of the rotating recording medium. A single reproduction scanner reproduces the main track and the sub-tracks on both sides of the main track from the rotating recording medium recorded at the recording position of the child or sub-track corresponding to the signal switching of the second reference signal. , a reproducing apparatus which obtains a reproduced output of the recorded main information signal of the main track from the reproduced signal, wherein the reproduced signal is reproduced from the fll l~ rack on both sides of the main l~ rack being scanned by the reproducing scanner. The first and second reference signals are discriminately separated from the reproduced signals of the reproduction scanner, and the third reference signal is discriminately separated, and based on the detected output signal of the separated third reference signal. , the image transmission path to the two input terminals of the comparison circuit of the tracking servo circuit for the detection outputs of the separated first and second reference signals is switched every rotation period, and thereby the error obtained from the comparison circuit is A reproducing apparatus for a rotating recording medium, characterized in that the reproducing scanner is configured to perform follow-up scanning on the main track based on a signal, thereby reproducing the recorded main information signal of the main track at least at a normal speed. The rotating recording medium has an electrode function, and the reproducing scanner is a scanning needle having a flat sliding surface that slides and scans the rotating recording medium and an electrode corresponding to the information bit width of the main track. , the green signal on the rotating recording medium is read and reproduced by detecting a change in capacitance formed between the rotating recording medium and the electrode. A reproducing device for the rotary recording medium described above.