JPS6321393B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a video signal recording system and a video signal recording and reproducing system, and particularly to a video signal recording system that records a video signal on a recording medium every desired frame (or field). The present invention also relates to a video signal recording and reproducing method for recording and reproducing video signals on a recording medium as described above.

Conventional technology and its problems As an example of a conventional video signal recording method and video signal recording/reproducing method, a laser beam is used to record a video signal (hereinafter referred to as a television signal) at high density on a disc-shaped recording medium, and this is then reproduced. I found a way to do it.
In this method, it is necessary to control tracking so that the laser beam accurately follows and scans the recording track during playback, and for this purpose, the reflected beam from the recording medium must be split, or the
As described in Publication No. 49-50954, various methods are available, such as dividing the signal reading beam into so-called three-point beams, one main signal reading beam and two tracking sub-beams, to perform tracking control. It was being done.

However, all of these methods have problems such as complicated and expensive equipment.

In addition, in conventional magnetic recording systems and video signal recording and reproducing systems, a tracking reference signal is recorded on a dedicated track using a plurality of dedicated magnetic heads, and each dedicated track is detected for playback by its own magnetic head. Although the above-mentioned tracking control is possible in principle, it has conventionally been almost impossible to implement considering the complexity of the device, practicality, performance, implementation cost, and the resulting loss of recording density.

Therefore, the present invention alternately switches a video signal and a tracking control reference signal for each track unit of a desired frame or field period and records the signals on a recording medium, and By using a recording method that records at least one reference signal in the video signal unrecorded portion of No. 2, and by generating a tracking control signal from the reference signal during playback, the information signal can be stably and reliably processed by at least a single signal conversion element. The purpose of the present invention is to provide a recording and reproducing method that can perform reproduction tracking.

Means and Effects for Solving the Problems The recording method of the present invention records a video signal and a tracking control reference signal by alternately switching each desired frame or field using at least one signal recording element, and At least one reference signal is recorded on the unrecorded portions on both sides of the signal recording track. Further, in the recording and reproducing method of the present invention, the recorded signal of the recording medium recorded as described above is reproduced by a signal conversion element, the reference signal is differentially reproduced to generate a tracking control signal, and this control signal is used to convert the signal. Tracking control of elements.

Since a single signal recording element records the reference signal together with the video signal, a signal converting element for tracking such as the sub-beam for tracking control is not required during reproduction. Furthermore, at least recording and reproduction of video signals can be performed using a single signal conversion element. Hereinafter, the present invention will be described in more detail along with examples.

Embodiment FIG. 1 is a perspective view showing a schematic configuration of an embodiment of the main part of the method of the present invention, and FIGS. 2A to 2C show track patterns of signals recorded and reproduced by the method of the present invention, respectively.
Enlarged view and record of the track pattern of the first embodiment,
FIG. 3 is an enlarged view of the track pattern of the second embodiment of the method of the present invention, FIG. 4 is a block system diagram of the first embodiment of the main part of the method of the present invention, and FIG. 6A to 6F are signal waveform diagrams for explaining the operation of the recording system in FIG. 4, respectively, and FIGS. 6A to 6F are signal waveform diagrams for explaining the operation of the reproduction system in FIG. 4, respectively. In Fig. 1, reference numeral 1 denotes a flexible disk-shaped magnetic sheet (hereinafter referred to as disk), which has a diameter of, for example, 30 cm, and is supported on a flat substrate 2 by a rotating flange of a disk motor (not shown), and is rotated at, for example, 1800 rpm in the direction of arrow 9. It is driven to rotate synchronously. During this rotation, disk 1
is spaced from the surface of the planar substrate 2 by a well-known technique, and a predetermined rotating surface is formed by the so-called air film effect.

The magnetic head 3, which is a signal recording element or a signal converting element, has a substantial video track width of, for example, 3 μm.
It is attached to the moving shaft shaft 7 via a thin flat spring 4, a buffer member 5, and a bracket, respectively, and the low pressure contact mechanism consisting of the spring 4 and the buffer member and the air film tensioning action of the disk 1 provide a low push force. The pressure allows it to slide into stable contact with the magnetic surface of the disk 1. Further, the low pressure contact mechanism is configured to act only in the vertical direction, and displacement on a plane parallel to the magnetic surface of the disk 1 is limited. 6
is a so-called moving coil mechanism that is constructed based on the same operating principle as an audio speaker, and its internal structure consists of a permanent magnet, a drive coil, and a yoke (all not shown), and the coil part is axially supported by a damper. A moving shaft shaft 7 is formed, and this moving shaft shaft 7 is displaced by a predetermined amount in the disk radial direction according to the direction and magnitude of the current applied to the drive coil.

Since the signal converter including the magnetic head 3 is attached to the moving shaft shaft 7, the magnetic head 3 can perform high-speed control in a direction perpendicular to the signal track formed on the disk 1 by the magnetic head 3. The signal converter and the moving coil mechanism 6 are mounted on a transfer mechanism section (not shown), and rotate the disk 1 in the radial direction 8 of the disk 1 when recording or reproducing signals. It is transported linearly at a slow speed synchronized with the Moving coil mechanism 6 when recording signals
The signal converter and the moving coil mechanism 6 are transferred in the radial direction 8 of the disk 1 without being controlled, and the information signal in units of TV signal frames is transferred to the magnetic surface of the disk 1 as shown in FIG. 2A. is magnetically recorded forming a spiral track locus.

To explain the recording operation of the method of the present invention,
The disk 1 is driven to rotate synchronously at, for example, 1800 rpm with reference to the frame pulse shown in FIG. 5C separated from the television signal to be recorded as shown in FIG.
By recording the television signal with the magnetic head 3 while moving at a predetermined pitch from the outer circumferential direction toward the inner circumferential direction, a spiral signal track mark in units of frame periods of the television signal is formed on the disk 1. The vertical sync pulse and horizontal sync pulse portions of the television signal are recorded side by side in the radial direction of the disc 1. Here, the above-mentioned television signal is thinned out every desired frame (or so-called frame skip recording) as will be described later.
In addition, in the first embodiment, two signals f _p1 and f _p2 having different frequencies are alternately recorded as tracking reference signals in the television signal non-recording portion every other desired frame.

The television signal to be recorded is as shown in FIG. 5A, with the vertical synchronizing pulse as a unit, and consists of a video signal portion 40 and a synchronizing signal portion 41, with the vertical synchronizing pulse being indicated by 42. Also, F ₁ , F ₂ ,
..., F ₇ is the first frame, the second frame, ...,
The seventh frame is shown. Here, the frame period is 1/30 second. This television signal is converted into a high frequency frequency modulated wave (RF signal) by frequency modulating a carrier wave with an appropriate frequency suitable for magnetic recording and reproduction using a frequency modulator (not shown). 21 to the switching circuit 22, where it is switched by a switching pulse from the input terminal 23. This switching pulse is an output pulse d shown in FIG. 5D of a flip-flop (not shown) triggered by a pulse shown in FIG. It is. Fifth
The pulse shown in Figure E is a flip-flop output pulse of opposite polarity to pulse d.

Due to the above-mentioned switching pulse d, the RF signals of even-numbered frames F ₂ , F ₄ , F ₆ , etc. in the illustrated waveform, which are only the portion corresponding to the positive polarity period, are switched and output from the switching circuit 22, and are synthesized. applied to circuit 24.

On the other hand, a flip-flop (not shown) that is triggered only by the rising edge of the pulse e shown in FIG.
Therefore, the period is 4 with mutually opposite polarity as shown in F and G of the same figure.
Pulses f and g of the frame are taken out, respectively, and these pulses are applied to first and second AND gates (not shown) to which the pulse e is applied to one input terminal, and the positive polarity portion of each pulse is applied to the first and second AND gates (not shown). Only the portion corresponding to is output from the gate. This allows the first
Pulses e and f are logically ANDed from the second AND gate to output the pulse h shown in FIG. A pulse i shown in is output.
Pulses h and i have a positive polarity period of 1 frame, a repetition period of 4 frames, and are different in time phase from each other by 2 frame periods, and furthermore, the positive polarity period of the switching pulse d is sequentially alternated every frame. The relationship is a repeating cycle of 4 frames. This pulse h is transmitted from the input terminal 27 as shown in FIG.
The pulse i is applied to the oscillator 30 from the input terminal 28, causing the oscillators 29 and 30 to oscillate only during their positive polarity periods, and stop oscillating during their negative polarity periods. The output signals of the oscillators 29 and 30 are respectively applied to the combining circuit 24 as reference signals for tracking control. Here, in this embodiment, the above-mentioned reference signal prevents the harmful effect of causing beat disturbance to the main information signal in the magnetic recording/reproducing transmission system, and also performs recording at a suitable level to achieve a high S/N.
The oscillation operations of the oscillators 29 and 30 are controlled so that the video information period in the recorded television signal is avoided and the reference signal is recorded only in the portion corresponding to the horizontal blanking period for the purpose of recording and reproducing the reference signal by do.

FIG. 5J shows a television signal in which horizontal synchronization signals are shown as units, 45 is a video information signal section, 46 is a horizontal synchronization pulse section, 47 is one horizontal scanning period (1H),
48 indicates horizontal blanking periods, respectively. However,
Although omitted for the sake of explanation, the horizontal sync pulse is separated from the input TV signal and generated into a 1H periodic pulse.
It is extremely easy to shape the pulse into a 1H period pulse in which only the width of the period corresponding to the horizontal blanking period has positive polarity, and in the embodiment, the recording position of the reference signal is set to the entire horizontal blanking period for the reason described later. Instead of inserting into the recording pattern traces, the 2H cycle is set every 1H, and one main information track is sandwiched between two kinds of reference signals on the recording pattern traces, and two types of reference signals are inserted into adjacent recording pattern traces in a cross-shaped pattern with a 1H shift. FIG. 5K shows the output waveforms of the oscillators 29 and 30.

Therefore, the oscillator control pulses h and i are applied only in the positive polarity period, and in relation to the horizontal period as shown in FIGS. 5J and K above, only in the horizontal blanking period corresponding portion, and In this case, the oscillator control pulses guided to the oscillators 29 and 30 are shaped so that they are oscillated only in 2H periods.

The oscillators 29 and 30 are simply composed of, for example, crystal oscillators, and a relatively low oscillation frequency of 1 MHz or less is sufficient.
The oscillation frequency of the oscillator 30 is selected to be 1MHz (hereinafter referred to as f _p1 ), and the oscillation frequency of the oscillator 30 is selected to be 700 KHz (hereinafter referred to as f _p2 ).
The respective oscillation outputs are applied to the combining circuit 24 to combine them together with the switched RF signal.
Three types of signals of frame period are combined. The three types of signals of one frame period shown in FIG. The magnetic head 3
This causes the even-numbered frame signals F ₂ , F ₄ , F ₆ ,
The reference signals f _p1 and f _p2 are sequentially and repeatedly recorded alternately with ... in between.

Next, the recording track pattern will be explained. In this embodiment, if the track width t of the magnetic head 3 is 3 μm and the track pitch p is 2 μm, then
The track pattern locus formed on the disk 1 by the recording signal as shown in FIG.
The result will be as shown in Figure B. In Figure B, if 11 is the frame pulse position of the recorded television signal, then
As mentioned above, disk 1 is synchronously servo driven at 1800 rpm in the direction of arrow 9 based on this pulse, so for convenience, if the H number of the frame pulse position is set to 525th H, then (1), ( 2), (3),
It is clear that (4), .

t ₁ , t ₂ , t ₃ ,..., tn are helical tracks formed by the magnetic head 3 in sequence, and f _p1 is (2), (4) on the track t ₁ of the first rotation. ,(6),…,
(520), (522), and (524) One cycle is recorded in each even-numbered horizontal blanking period corresponding portion of the H position, and recording starts from the frame pulse position 11 and ends at the position 11. When forming the second track _t2 , in this embodiment, the track width t is equal to the track pitch p.
Because of the larger size, the inner edge of track t ₁ is shown as 16, and the outer edge of track t ₂ is shown as 17. Tracks t ₁ and t ₂ have an overlapping part 14, and overlapping recording of signals is performed in this part. It is done. This overlap portion 14 is 1 μm when t=3 μm and p=2 μm. Subsequently to track _t1 , frame _F2 of the main RF signal is recorded by the magnetic head 3 as shown in FIG. 5B, forming track _t2 . In this embodiment, track _t1 is recorded. After recording the reference signal f _p1 at , the television signal (RF signal) of frame F ₂ is partially superimposed and recorded on track t _2. As a result, a predetermined width of 1 is
As shown in an enlarged view in FIG. 2C, the reference signal of f _p1 recorded at No. 3 is slightly demagnetized at the portion shown at 19 because the overlapping portion 14 is overwritten.

The RF signal of frame F ₂ is also at frame pulse position 1.
Recording starts from position 1 and exactly one rotation and one frame of the television signal is recorded on track _t2 up to this position 11. Next, on the third track _t3 , the reference signal f _p2 corresponds to the (1), (3), (5), ..., (521), (523)th horizontal blanking period. The position and width are recorded, but due to the relationship between the track width of the magnetic head 3 and the transfer pitch, the scanning width t of the track _t3 also corresponds as shown by the broken line, so when the track _t3 is formed, the track _t2 is also recorded. It is clear that as a result of the overlapping portion 14' of the track t2, overwriting of the signal is performed in a part of the width of the recorded signal of the track _t2 and a portion corresponding to the odd-numbered horizontal blanking period. be.

After the recording of the reference signal f _p2 on the _third t3 track up to frame pulse position 11 is completed, the main RF signal _F4 continues on the fourth track _t4 up to pulse position 11 within one rotation and one circumferential period. Recording is performed, and a part of f _p2 already recorded on track _t3 overlaps, and recording is performed while being demagnetized by similar overwriting. As a result, the signal f _p2 is formed as a bridge over the information tracks t ₂ and t ₄ of the main RF signal indicated by diagonal lines. In addition, the main RF signals are not recorded in the guard band portions 15 and 15', and the reference signals f _p1 and f _p2 are arranged within the respective corresponding horizontal blanking periods. It is 1μm wide.

Thereafter, by repeating the same procedure as above, frame pulse position 11 is set as the start and end point of switching recording in units of one rotation period of disk 1, that is, frame period (1/30 seconds), and continues on track _t5 .
f _p1 , main RF signal of F ₆ on t ₆ , f _p2 on t ₇ in the order
For example, from the outer circumference side of disk 1 to the inner circumference side while sequentially switching the records up to tn.
Recording was continued for 30 minutes, and 54,000 tracks were recorded to form the track pattern shown in FIG. 2B.

Note that when track pitch < track width as in this embodiment, as is clear from the above explanation, the successive track widths inevitably overlap and some parts are recorded overlappingly, and during playback, Therefore, three types of information signals are always reproduced at the same time.

Therefore, in principle, the present invention achieves the initial purpose even if the reference signals f _p1 and f _p2 , including the video information corresponding portion of the television signal, are recorded as continuous waves by simply changing the frequency every other rotation. It is possible. However, this method has the disadvantage that when the reference signal is recorded at a strong level in order to be reproduced with a high S/N ratio, it causes beat disturbance to the television signal when the signal is reproduced.
On the other hand, when a reference signal is inserted and recorded during a period equivalent to the horizontal blanking period as in this embodiment,
A feature is that the reference signal recording of f _p1 and f _p2 does not cause any hindrance to the main information signal.

Therefore, for example, in frame unit recording of the entire H cycle, the position corresponding to the horizontal blanking period of 525 lines is recorded.
According to the method of inserting and recording f _p1 and f _p2 , the beat disturbance described above does _not occur, but it is better to insert and record _{f p1} and f _p2 every 2H period as in this embodiment. It is clear that the sensitivity can be further increased,
In addition, the horizontal scanning frequency of the Japanese-American standard television signal is 15.75 KHz, but even a pulse train of about 7 KHz, which is half this, is sufficient as tracking information, and according to the applicant's experimental results, when the disk rotation speed is 1800 rpm. Since the basic disk eccentricity error component is 30Hz, sufficient tracking correction accuracy was obtained for eccentricity of about ±100μm even with a 3H cycle pilot signal.

In addition, in this example, each of f _p1 and f _p2 is set to 2H
Inserting and recording each period at predetermined positions shifted by 1H means setting and resetting the separated H synchronization pulses with frame pulses, and
This can be easily generated using a logic circuit that counts down the H synchronization pulse by 1/2.

Next, a second embodiment of the recording track pattern will be explained with reference to FIG. This embodiment shows a track pattern formed on the disk 1 when the track pitch p and the track width t are made equal. For example, if p = t = 2 μm, the reference signal f _p1 is recorded for track t ₁ , the signal of frame F ₂ is recorded for track t ₂ , the reference signal f _p2 is recorded for track t ₃ , and the frame F for track t ₄ is recorded. ₄ are opposed to each other in the correspondence shown in FIG. _p1 , f _p2
is recorded almost to its full width, and there is no overlapping recording of the signal, and during the reproduction tracking operation, the reference signals f _p1 and f _p2 are not reproduced simultaneously, and one reference signal from the shifted direction is instantaneously recorded. It will be played.

Therefore, tracking control reference signals f _p1 , f _p2
In this embodiment, it is not a problem that beat interference is caused to the main RF information signal as in the case of the overlap recording method (p<t) in the first embodiment.
As a result, whether the reference signals f _p1 and f _p2 are continuously recorded or
Alternatively, it may be performed by inserting and recording within the entire horizontal blanking period. Furthermore, the present invention is not limited to the first and second embodiments described above, and p>t may also be used.

Next, the operation of the reproduction system according to the present invention will be explained. During reproduction, the recording/reproduction changeover switch 26 is switched to its fixed contact P side. The weak signal from the magnetic head 3 is amplified to an appropriate level by the preamplifier 31 in FIG. 4, and then sent to the output terminal 3 as a reproduced signal.
2 to an RF demodulator (not shown), where it is demodulated to the original television signal.

Furthermore, the reproduced signal including the reference signals f _p1 and f _p2 amplified at the front stage of the preamplifier 31 is the signal f _p1 , f _p2
The signals are applied to the amplifiers 33 and 34 for separate amplifiers, respectively. The preamplifier 33 has a steep frequency characteristic only for the frequency corresponding to f _p1 , and the preamplifier 34 has a steep frequency characteristic only for the frequency corresponding to f p1.
This is a pre-filter amplifier designed to have steep frequency characteristics only at frequencies corresponding to f _p2 . The output signals of these amplifiers 33 and 34 are
It is separated into only f _p1 and f _p2 and the playback levels are aligned.
It is led to the next polarity switching gate switching circuit 35, where the polarity of f _p1 and f _p2 is switched every two frame periods at least during normal playback by a switching pulse from an input terminal 36. Output.

As is clear from the so-called field-skip recording and reproducing technology in conventional magnetic recording and reproducing technology, television signals are composed of field-by-field and frame-by-frame signals that have many correlations. The signal recording capacity can be increased by skip recording and reproduction, and in order to convert it into real time in the reproduction process, it is necessary to scan and reproduce the same track twice, at least in normal reproduction.

During normal playback, only the recorded even-numbered frame signals F ₂ , F ₄ , F ₆ , ... are played back because odd-numbered frames are missing during signal recording, but the missing F ₃ , F ₅ , F ₇ , . . . , F ₂ , F ₄ .F ₆ , . From this reproduced signal, the preamplifier 33 separates a reference signal as shown in FIG. 6B, and the preamplifier 34 separates a reference signal f _p2 as shown in FIG. 6C.

Now, for example, in FIG. 2B, the magnetic head 3 is moved from the position shown in 3a to the disk 1 with eccentricity, with the tracking servo not configured and the movement of the head 3 in the inner radial direction stopped. If playback is started without any command, at the time of playback start (frame pulse position 11), the maximum playback from track t ₂ is reached.
RF output is obtained. However, as the magnetic head 3 moves away from this starting position 11 in the rotational direction, the magnetic head 3 scans on the same recording radius, whereas the tracks such as t ₂ are formed in a spiral, so the tracks The shift occurs in the direction of the outer circumference of the disk, and near the end of one revolution, the reproduction output level deteriorates to about 1/3 in the case shown in the figure. Similarly, when the magnetic head 3 is at the position shown in 3b in Figure 2B, it traces only on track _t4 at the beginning of the first playback, but slides on track _t3 near the end of one rotation. Therefore, the RF signals of tracks _t2 and _t4 are reproduced simultaneously, resulting in an extremely unsightly reproduced image accompanied by beat disturbance. In other words, it is clear that if the head 3 is transported without tracking on the recording track pattern shown in FIG. 2B or FIG. 3 in the same way as when recording, a satisfactory reproduced image will not be obtained at all. . on the other hand,
The level relationship between the signals f _p1 and f _p2 reproduced when the magnetic head 3 is located at the position 3a above is that near the frame pulse position 11 at the start of reproduction, f _p1 and f _p2 are at the same level. As it is clear from the fact that the reproduced track shifts spirally toward the inner diameter of the disk as the disk 1 rotates, the reproduction level of the signal f _p1 gradually increases as the disk rotates, and conversely, the reproduction level of the signal f The playback level of _p2 gradually decreases, and near the end of one rotation,
It is clear that f _p1 is played at maximum level and f _p2 is played at minimum level.

Therefore, the output signals of the preamplifiers 33 and 34
f _p1 and f _p2 are introduced into the detectors 37 and 38 through the gate switching circuit 35, where the envelopes are detected and the levels are converted into DC voltages and applied to the tracking servo circuit 39, respectively, and the differential amplifier (not shown) and control technology that compares the phase and level of the two using well-known servo circuit technology, the driving power is transferred from the circuit 39 to the magnetic head 3.
By applying a voltage to the moving coil mechanism 6 to which the magnetic head 3 is attached, the magnetic head 3 is caused to constantly scan on a predetermined track. In other words, the closed-loop tracking servo loop described above ensures that the reproduction levels of f _p1 and f _p2 always match and are reproduced at a constant level.In other words, regardless of the rotational position and phase, the reproduction from the track is maintained. Tracking control is performed so that the RF output level is always at the maximum peak value.

Here, when the output signal level of the wave detector 37 becomes larger than the output signal level of the wave detector 38, the magnetic head 3 is controlled to move toward the inner circumference of the disk 1, and the output signal level of the wave detector 38 becomes higher than that of the wave detector 38. 3
A servo loop is preconfigured to compare the level relationship between the two with polarity such that when the output signal level becomes higher than the output signal level of 7, the magnetic head 3 is controlled to move toward the outer circumference of the disk 1. Therefore, when the switching pulse from the input terminal 36 is not applied, the output signals f _p1 ,
f _p2 is applied to the detectors 37 and 38 via the gate switching circuit 35, respectively. Therefore, in this case, for example, the magnetic head 3 is on the track t ₂
If the magnetic head 3 is to be traced on the track t3 after reproduction up to (525)H, which is the end position of one frame of the reproduction of the track _t2 , the magnetic head 3 will start tracing on the track _t3 , as shown in FIG. 2B. This truck
From _t3 , only the signal f _p2 is reproduced at the maximum level, and as a result, the output level of the detector 38 becomes maximum, and the magnetic head 3 is rapidly and instantaneously moved toward the outer circumference of the disk due to the above polarity setting, and the signal f _p1 and
Since the tracking servo is applied at the position where the playback level of f _p2 reaches the equilibrium level, the track is always pulled back to track only track t ₂ even in the discontinuous track portion at the frame pulse position 11, and in this case, only track t ₂ is tracked. A frame-by-frame still image is obtained by repeatedly playing back the image.

Next, in the normal reproduction mode, the signal pick-up body is transferred to the disk 1 in the radial direction 8 via a transfer mechanism (not shown) at a predetermined pitch (in the embodiment) at a speed synchronized with the rotation of the disk 1, as in the case of recording.
2μm), but as mentioned above, because of frame skip recording, if one frame is recorded per track per revolution, the same track may be scanned and played back twice. There is a need to. For this purpose, for example, in FIG. 2B, the magnetic head 3 traces the track _t2 twice from the _t2 track position on the right side of the frame pulse position 11 to the discontinuously adjacent track _t4 . It is necessary to move the head to the track position indicated by the broken line 3b, and this operation is performed as follows.

That is, if the tracking servo is operated with the polarities of f _p1 and f _p2 unchanged from the state where the magnetic head 3 approaches the above position 11, the magnetic head 3 will not move even if the pickup body is moved in the radial direction. does not move from track t ₂ to track t ₄ , and continues to trace only track t ₂ , but after tracing twice for track t ₂ , it moves to position 1.
By reversing the polarities of f _p1 and f _p2 from 1 and applying them to the tracking servo circuit 39 with opposite polarities, the magnetic head 3 is moved in the inner radial direction by detecting f _p2 , contrary to when tracing on track _t2 . Further, upon detection of f _p1 , a tracking servo control operation is performed so that the magnetic head 3 is moved in the outer radial direction.

In this embodiment, a switching pulse as shown in FIG.
Gate switching circuit 3 from input terminal 36 in the figure
5, the amplifiers 33,3
The output signals f _p1 and f _p2 shown in FIGS. 6B and 6C of 4 are switched every two frames. As a result, the output signals of the switching circuit 35 have different frequencies as shown in FIG.
The waveform has f _p1 and f _p2 arranged alternately for each frame, and is supplied to the detectors 37 and 38, respectively. As a result, the magnetic head 3 changes the track t ₂ to 2
After tracking has been traced, tracking control is performed so that the playback levels of f _p1 and f _p2 only on track t ₄ maintain an equilibrium state, that is, the playback RF level from track t ₄ maintains the maximum value. .

Thereafter, the magnetic head 3 traces the track _t4 twice, and then traces the reproduced signals of f _p1 and f _p2 from position 11 again to the detectors 37 and 38, thereby reversing the input to the detectors 37 and 38, thereby tracing the track _t6 . The reference signals f p1 and f p2 are controlled to be tracked and traced, and thereafter, the reference signals f _p1 and f _p2 are sequentially transferred in the direction of the inner diameter of the disk by the detector input switching operation every two frame periods, so that so-called normal reproduction is performed.

Also, for example, the transfer speed of the pick-up object is reduced to 1/3 of the normal playback speed (however, the rotation speed of disk 1 is the same as the normal playback speed), and the same track is traced back three times (2 x 3 =6
It is clear from the above explanation that a 1/3x speed slow motion image can be obtained by switching the signals f _p1 and f _p2 so that It is clear that a structure can be constructed that allows operations such as single-frame forwarding, reverse playback, and high-speed cueing.

Note that the tracking servo circuit 39 may be a well-known circuit as described above, and first, the input circuit section includes two
The configuration is such that the two error signals are compared using a differential amplifier, but when reproducing a disc with track pattern traces of the first embodiment shown in FIG. 2B, strictly speaking, as shown in FIG. 2C. Since a portion 19 of the reference signals f _p1 and f _p2 is demagnetized by overwriting, it is desirable to correct the level drop during playback by taking into account the detection output and introduce it into the servo circuit 39.

In addition, when reproducing a disc with track pattern traces of the second embodiment shown in FIG. 3, signal processing for servo tracking for signals f _p1 and f _p2 separated from the reproduced signal is also performed as shown in FIG. 4. A substantially similar configuration may be used; in this case, the signal f _p1 or f _p2 is reproduced from only one of the tracking deviation directions, and the level of both output signals f _p1 and f _p2 always maintains a balanced state at the minimum value. There is essentially no difference in that the tracking control can be performed in such a manner that the main RF output signal level is always outputted to the head at its maximum level.

FIG. 7 is an enlarged view of the track pattern of the third embodiment of the method of the present invention, and FIG. 8 is an enlarged view of the track pattern of the third embodiment of the method of the present invention.
A block system diagram of an example is shown. In each figure, the same parts as in Figures 2A to C and 4 are designated by the same reference numerals.
The explanation will be omitted. In the track patterns of the first and second embodiments, the two tracking control reference signals were sequentially and alternately recorded at each rotation period on the tracks corresponding to the non-recorded portion of the television signal, but this was further modified. This is the present example.
That is, in this embodiment, only the first reference signal f _{p1 is used as a tracking control reference signal in the non-recording portion of the sequential television signal, and the horizontal signal of the television signal is changed every 3H period, for example, as shown by the solid line in FIG} . The second reference signal f p2 is recorded at a position corresponding to the blanking period, and the second reference signal f _p2 is recorded together with the television signal and at the horizontal blanking of this television signal recording track (t ₂ , t ₄ , t ₆ , t ₈ , ...). At the position corresponding to the erasing period, switching is recorded every 3H period as shown by the broken line in the same figure, and the signal f _p2 is recorded at the time of playback.
This signal is used as a reference signal for gate discrimination of f _p1 .

In FIG. 8, first, during recording, the input terminal 27',
From 28', first and second switching pulses, for example, whose positive polarity period is equal to the horizontal blanking period and whose repetition period is 3H, are generated by the oscillators 29 and 30, respectively.
is applied to The rising points of the first and second switching pulses are shifted by 1H from each other.
That is, the second switching pulse rises 1H after the first switching pulse rises. Here, to explain how to generate these switching pulses, first, by counting down by 1/3 using the horizontal synchronizing signal separated from the television signal to be recorded as a reference.
Obtain a 3H cycle repeating pulse. However, the switching pulse is obtained by extracting the frame pulse from the synchronization signal separated at this time, and using it as a reference, omitting one or more horizontal synchronization signals at a predetermined recording position from the frame pulse recording position. It is. For example, if the horizontal synchronizing signal recording position (525) of the spiral tracks t ₂ , t ₄ , t ₆ , . . . in the track pattern shown in FIG. Only the first (1) horizontal synchronization signal is missing,
By setting only this missing part at 2H intervals,
A desired switching pulse is obtained by generating continuous H-period pulses with the number of horizontal scanning lines as 524, and then processing the H-period pulses so as to count down by 1/3 using a counting logic circuit. be able to.

Among the output signals of the oscillators 29 and 30 whose oscillation is controlled by this switching pulse, the output signal of the frequency _p1 of the oscillator 29 is generated during the period when the output RF signal of the switching circuit 22 is missing, and when the horizontal return of the recorded television signal is detected. Only the line blanking period is output every 3H period, while the output signal of the frequency _p2 of the oscillator 30 is within the horizontal blanking period of the television signal, and
It is output every 3H periods and is superimposed on the output RF signal of the switching circuit 22 at an appropriate level. As a result, the track pattern trace on the disk ₁ is _such that the signal _p1 shown by _the solid line in FIG.
As shown by the broken line, _p2 is superimposed and recorded on even-numbered television signal recording tracks t ₂ , t ₄ , t ₆ , . . . shown by diagonal lines. Further, the signals _p1 and _p2 are recorded every other circular track, and are recorded side by side in the direction of the circular center with a period of 6 tracks, for example, t ₁ , t ₇ , etc., and _p1 and _p2 are 1H apart from each other. recorded at different positions.

Next, the operation during playback will be explained. The signal _p1 taken out from the preamplifier 33 is applied to gate circuits 52 and 54, respectively, by the same operation as explained in FIG. 4. In addition, the signal _p2 taken out from the preamplifier 34 is used as a trigger pulse with an oscillation time constant of approximately
The voltage is applied to the 1.5H monostable multivibrator 50 to trigger oscillation. This oscillation output is applied to gate circuits 52 and 54 from input terminals 51 and 53, and the reproduced signal _p1 is output from the gate. For example, at the time phase corresponding to the positive polarity period (approximately 1.5H) of the output pulse of the multivibrator 50, the gate circuit 52 generates a signal from the time of reproducing the signal _p2 .
After 1H, the signal _p1 reproduced from the inner circumferential position of the reproduction track is output from the gate, and at the time phase corresponding to the negative polarity period (approximately 1.5H) of the pulse, the signal p1 is output from the gate circuit 54 from the time when the signal _p2 is reproduced.
After 2H, the signal _p1 reproduced from the outer circumference side position of the reproduction track is outputted from the gate. The output signals of the gate circuits 52 and 54 are outputted as tracking control signals by the same operation as explained in FIG. 4, and are used to control the tracking of the magnetic head 3 so as to accurately scan the image track.

In this embodiment, normal reproduction and special reproduction such as slow and still reproduction can be performed by performing the following signal processing at the frame pulse position 11 of the recording signal during reproduction. In other words, a reproduced frame pulse whose phase substantially coincides with the frame pulse position 11 of the signal switching during recording is obtained, and by this frame pulse, positive and negative polarity signals corresponding in phase to the vertical blanking period of the reproduced television signal are obtained. Shape into pulse. This is applied as a jumping pulse to the tracking servo circuit 39 from the input terminal 55. This jumping pulse moves the moving coil mechanism to the frame pulse recording position 1 during the vertical blanking period.
By setting the polarity, pulse width, and amplitude of the frame pulse to predetermined values, the servo configuration is such that the part corresponding to 1 can be controlled instantaneously from the outside, and by setting the polarity, pulse width, and amplitude of the frame pulse to predetermined values, the level discontinuity of the recording position 11 is prevented during playback. It is easy to quickly drive the head from the position to a track position shifted by one track from the previous stage using a tracking control element using a well-known technique, and the switching control operation may be performed in conjunction with the above-mentioned playback operation mode.

Furthermore, in this embodiment, since the main information signal and the tracking control reference signal can be reproduced simultaneously at any time, _p2 may be recorded in the video track portion when _p1 is recorded.

As described above, in this embodiment, during signal reproduction, the signal _p1 reproduced 1H after the reproduction position of _p2 is always the signal _p1 from the adjacent TV signal non-recorded portion on the inner circumference side of the reproduced video track. Since the signal _p1 reproduced 2H after the _p2 reproduction position is always the signal _p1 from the adjacent TV signal non-recorded part on the outer circumference side of the reproduced video track, a gate pulse is generated by separating _p2 from the reproduction signal, and By gate outputting the regenerated and separated _p1 , _p2
p1 played 1H after the playback output position of
By outputting from the discrimination gate whether _p1 has been reproduced after 2H, the position in the track deviation direction is identified and tracking control is performed.

Note that the present invention is applicable not only to devices using magnetic recording and reproducing technology for television signals as described above;
It goes without saying that it can be applied to devices that perform high-density recording of television signals using optical beams and read and reproduce signals using optical beams. It is also possible to use the known contact-type scanning stylus in a capacitive or mechanical vibration type signal pickup configuration without a stylus guide groove in combination with a tracking control element.

FIG. 9 shows an enlarged view of the track pattern of a fourth embodiment of the method of the present invention. Using an optical beam, for example, a pit of the reference signal _p1 is inserted and recorded on the first track _t1 at a position corresponding to the horizontal blanking period of the television signal recorded on track _t2 , and a pit of the television signal is recorded on the track _t2 . Track the main pit pattern
At _t3 , pits of the reference signal _p2 are inserted and recorded in the horizontal blanking period. Thereafter, similarly, these three types of information signals are sequentially and alternately switched and recorded every rotation of the disk. Further, during reproduction, the signals _p1 and _p2 are separated and reproduction tracking control is performed in the same manner as described above. In addition, in this embodiment, overlap recording is performed as in FIG. 2B, but the signal
_p1 , _p2 and the track of the main information pit may be recorded at non-overlapping positions. In addition, compared to the conventional method of regeneration using a scanning needle that slides and scans within the guide groove, since no guide groove is required, the contact width area of the scanning needle with the disc surface can be greatly expanded, which sufficiently extends the life of the scanning needle. Yes, slow motion,
A video player that can optionally play back stills can be created.

FIG. 10 is a partial enlarged view of the track pattern of the fifth embodiment of the system of the present invention, in which the television video signal of one field per one rotation of the disk is formed in a spiral shape with p<t between tracks t ₁ , t ₂ , . . . It has overlapping portions 14, 14'. In this embodiment, disk 1 is phase-locked to the vertical synchronization pulse of the video signal.
Signals are recorded and reproduced by being synchronously rotated at 3600 rpm. In the case of Japanese and American standard television video signals,
As is well known, the number of horizontal scanning lines in one frame is 525.
Odd-numbered fields and even-numbered fields interlaced each other to form a frame image, so when recording and reproducing signals at least in field units, one field is
From the relationship of 262.5H (=525/2), when the reference signals _p1 and _p2 are alternately inserted and recorded in the portion corresponding to each horizontal blanking period every rotation of the disk, the track pattern will be as shown in Fig. 10. . In the same figure, 11
indicates the vertical synchronization pulse recording position. On track t ₁ , (1), (2), (3), ..., (260),
A reference signal _p1 shown by a single solid line is recorded in the (261) and (262)th first (odd) field corresponding to horizontal synchronizing pulse recording, and subsequently, the first (odd) field of the video signal is recorded on track _t2 . 2 (even numbered) fields are recorded in the broken line track section, and the horizontal sync pulse positions of this even numbered field are (263), (264),...
(524) (525). Further, on the third track _t3, as shown by two vertical solid lines, a reference signal is
_p2 is inserted and recorded at the corresponding horizontal synchronizing pulse recording position of the third (odd number) field as shown in the figure.

Here, the vertical broken line portion of the horizontal synchronizing pulse position 100 of the even field in the video signal recorded and formed on the tracks t ₂ , t ₄ , t ₆ , . . . is the track t ₁ , t ₃ , t ₅ , .
...The reference signals _p1 and _p2 to be inserted and recorded at the horizontal synchronizing pulse positions corresponding to the odd-numbered fields above have a phase relationship exactly 1/2H shifted as shown in the figure.

However, as in this embodiment, when recording field unit signals in particular in an overlap manner,
Since the recording positions of _p1 and _p2 are phase-inserted to approximately the center of the video signal recording track section, there is a risk that the reference signals _p1 and _p2 may cause beat disturbance to the reproduced video signal.

Therefore, since the track pattern shown in FIG. 10 is not preferable in terms of reproduction quality, when the present invention is applied to record signals in units of one field per revolution of the disk, the insertion recording positions of the reference signals _p1 and _p2 are By configuring the recording phase of the reference signals _p1 and _p2 to be inserted and recorded with a 1/2H shift as shown in FIG. 11 so as to match the phase with the horizontal blanking period part of the recorded video signal part, beat disturbance can be prevented. It can be removed with good results.

Although the above example shows the case where the formation track pattern of the present invention is implemented in a spiral format, the present invention is not limited to this. In the case of magnetic recording and reproducing by forming a circular track locus, the above three types of information signals may be magnetically recorded and reproduced so as to be appropriately arranged. A device may be constructed in which drive elements are appropriately combined so that the recording and reproducing operations of these signal converters are sequentially and alternately performed.

Further, in each of the embodiments shown in FIGS. 7 and 8, the reference signal _p2 is intentionally inserted and recorded on the track where the video signal is recorded for the purpose of discriminating the reference signal _p1 . The method of the present invention is not limited to this, but the initial purpose is achieved by recording only a single reference signal at every predetermined period and discriminating the playback time phase relationship of this single reference signal during playback. It is possible.

For example, in FIG. 7, when recording and reproducing frame video signals in units of vertical synchronization signal recording position 11, six tracks ( Considering that the recording phase of a single reference signal is regularly arranged and recorded every period (if only the reference signal recording track is considered, there are 3 tracks), it can be logically counted based on the above position 11, or approximately By means such as triggering a monostable multivibrator with a time constant of 3H with the single reference signal and sequentially gating the reproduced single reference signal,
When reproducing a scanning track, tracking may be performed while distinguishing the relationship between the reproduction phases of the sequentially reproduced reference signal _p1 sequence and detecting the direction of deviation.Furthermore, the reproduction signal may be subjected to complete peak value control. Although this cannot be achieved, the initial objective can be achieved in the same way by configuring the reference signal _p1 and the RF signal reproduced from the video track to be compared at a predetermined level ratio.

Furthermore, FIG. 10 describes an example in which a vertical synchronizing pulse is separated from a video signal to be recorded, the disk is driven to rotate synchronously, and exactly one field of video signal is recorded for one rotation of the disk. However, in the present invention, for example, 262 or 263 pieces per revolution of the disk are processed in units of integral multiples of the horizontal scanning period.
It is also possible to count the horizontal synchronizing pulses addressed to each individual field, servo drive the disk, and record in field units without the irregular discontinuous period of H/2 as in the fifth embodiment described above. It is clear from the above description that the method can be implemented as is.

Furthermore, the present invention is not limited to magnetic recording and reproducing devices using the frame period of television signals as units, but may also be applied to devices that record and reproduce signals in field units and in units of arbitrary integral multiples thereof. It goes without saying that the intended purpose can be achieved, and by making some modifications, it is also conceivable that the present invention can be applied to a device for detecting a tracking error signal of a magnetic recording/reproducing device using a video tape.

Furthermore, the method of the present invention is not limited to the one shown in FIG. 4 or FIG. 8, and the track pattern of the recording medium is shown in FIG. It suffices if it is formed as a diagram or the like. Also,
The track reference signals do not have to be of two types, _p1 and _p2 , and the first and second signals having different frequencies may be recorded in adjacent main information non-recorded parts of the main information track and in the video signal track. Just do it.

Furthermore, the present invention is not limited to the above-mentioned embodiments, and the present invention is not limited to the above-mentioned embodiments, and the present invention is not limited to the above-mentioned embodiments.
Recording is inserted into the unrecorded portion between at least adjacent video signal recording tracks every 3H and at different positions every 3 tracks in units of cycles, and during playback, the playback time phases are discriminated and gated. In particular, by having a configuration that detects the direction and amount of deviation during mistracking, the purpose of tracking control can be achieved in the same manner as in the above-mentioned embodiments.

Effects of the Invention As described above, according to the recording method and video signal recording/reproducing method of the present invention, a reference signal can be recorded at a predetermined position simultaneously with a video signal with a simple configuration, and the video signal can be used for recording the reference signal. By inserting and recording the reference signal only in the corresponding portion within the horizontal blanking period of the recorded video signal, the reference signal can be recorded without causing beat disturbance such as cross-modulation in the video signal. can be reproduced with high S/N.

In addition, at least video signal recording and playback can be performed stably and reliably with a single signal conversion element, the configuration is simpler than conventional equipment, and the storage of recorded information signals is improved and compatibility between equipment is improved. , and during playback, from normal playback to still playback, frame-by-frame forwarding, information search, cueing, etc., can be performed as desired in relation to the device mode. In addition, since the video signal is recorded every desired frame (or field), the recording density can be improved, especially when applied to a magnetic recording and reproducing device that uses a rotating magnetic medium as the recording medium.
The main information track and the tracking control track are sequentially and alternately recorded on the rotating magnetic medium by means of a spiral track in conjunction with linearly transporting a single signal recording/reproducing magnetic head at a predetermined pitch, making it extremely simple. The initial purpose can be achieved by a suitable configuration. Furthermore, since it is possible to record and form a track pattern so that the recording pitch of the magnetic head as it moves in the radial direction of the rotating magnetic medium is less than or equal to the recording track width of the magnetic head, it is possible to improve the stability of tracking control and increase the recording density. This is extremely advantageous, and if necessary, by setting the head channel system to two channels and sequentially alternating the signal recording and reproducing operations, it is possible to record and reproduce TV video information without skipping recording and without interrupting the TV video information. It has many features such as the ability to

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a schematic configuration of one embodiment of the main part of the method of the present invention, and FIG.
The track pattern of the reproduced signal, an enlarged view of the track pattern of the first embodiment and a schematic diagram of an example of the recorded and reproduced signal, and FIG. 3 shows the second embodiment of the present invention.
An enlarged view of the track pattern of the embodiment, FIG. 4 is a block system diagram of the first embodiment of the main part of the system of the present invention, FIG. 5 is a signal waveform diagram for explaining the operation of the recording system of FIG. 4,
Fig. 6 is a signal waveform diagram for explaining the operation of the reproduction system in Fig. 4, Fig. 7 is an enlarged view of a track pattern of the third embodiment of the method of the present invention, and Fig. 8 is a second embodiment of the main part of the method of the present invention. The block system diagram of the example, FIG. 9 is an enlarged view of the track pattern of the fourth embodiment of the method of the present invention, and FIG.
11 and 11 are enlarged views of track patterns of the fifth embodiment of the present invention and a modification thereof, respectively. 1...Disc-shaped magnetic sheet (disk), 3...
Magnetic head, 6...Moving coil mechanism, 22
...Switching circuit, 24...Synthesizing circuit, 2
9, 30... Oscillator, 31, 33, 34... Preamplifier, 35... Gate switching circuit, 3
7, 38...Detector, 39...Tracking servo circuit, 52, 54...Gate circuit.

Claims (1)

[Scope of Claims] 1. A video signal and a tracking control reference signal are alternately switched and recorded for each track unit of a desired frame or field period by at least one signal recording element on a recording medium, and the video signal is A video signal recording method characterized in that at least one reference signal for tracking control is recorded in video signal non-recorded portions on substantially both sides of a recording track. 2. By providing a plurality of the above-mentioned signal recording elements that record a video signal every desired frame or field, and by sequentially recording the video signal with the plurality of signal recording elements without interruption, the video signal can be recorded without thinning out the video signal. 2. The video signal recording method according to claim 1, wherein all of the video information is recorded. 3 At least once in the radial direction of the rotating magnetic recording medium at a speed synchronized with the rotational speed of the rotating magnetic recording medium.
A head assembly consisting of several magnetic heads is linearly transported, and the magnetic heads alternately transfer the video signal and the tracking control reference signal onto the rotating magnetic recording medium in units of frames or field periods of the video signal. In the case of recording by sequential switching, recording and forming a track pattern in which the recording pitch of the magnetic head in the radial direction of the rotating magnetic recording medium is less than or equal to the recording track width of the magnetic head, and
In the video signal recording tracks, horizontal synchronizing signals are recorded in parallel in the perpendicular direction of each track, and the recording tracks for the tracking control reference signal are substantially arranged on both sides of the video signal recording track. Further, a video signal recording method characterized in that the tracking control reference signal is intermittently recorded in a portion corresponding to a horizontal retrace period of the video signal. 4. A video signal and a tracking control reference signal are alternately switched and recorded for each track unit of a desired frame or field period by at least one signal recording element on a recording medium, and substantially all of the recording track of the video signal is recorded. At least one tracking control reference signal is recorded in the non-recorded portions of the video signal on both sides, and during playback, substantially from the recording track of the tracking control reference signal disposed on both sides of the recording track of the video signal. A video signal characterized in that the reference signal is reproduced by the signal conversion element, a tracking control signal is generated from the reproduced reference signal, and the video signal is reproduced by the signal conversion element which is caused to perform a tracking control operation by the control signal. Recording and playback method. 5 At least one magnetic head records the video signal and the tracking control reference signal on the recording medium by alternately switching each frame or field period of the video signal, and substantially recording the recording track of the video signal. The magnetic head reproduces the tracking control reference signal from recording tracks of the tracking control reference signal disposed on both sides, and the magnetic head is subjected to tracking control using the tracking control signal generated from the reproduced reference signal. A video signal recording and reproducing method characterized in that the video signal is reproduced by: 6 Of the tracks that are sequentially formed by at least one magnetic head recording a video signal and a tracking control reference signal on a recording medium by alternately switching each frame or field period of the video signal, Horizontal synchronizing signals are recorded on the recording tracks of the video signal in parallel in the perpendicular direction of each track, and the recording tracks of the tracking control reference signal are substantially disposed on both sides of the recording track of the video signal. Also, the tracking control reference signal is intermittently recorded in a portion corresponding to the horizontal retrace period of the video signal,
A video signal characterized in that the magnetic head reproduces the tracking control reference signal together with the video signal, and the video signal is reproduced by the magnetic head which is subjected to tracking control using a tracking control signal generated from the reproduced reference signal. Recording and playback method. 7 At least once in the radial direction of the rotating magnetic recording medium at a speed synchronized with the rotational speed of the rotating magnetic recording medium.
A head assembly consisting of several magnetic heads is linearly transported, and the magnetic heads alternately transfer the video signal and the tracking control reference signal onto the rotating magnetic recording medium in units of frames or field periods of the video signal. Among the tracks that are sequentially formed by switching and recording, the horizontal synchronizing signal is recorded in the recording track of the video signal in a line perpendicular to each track, and the recording track of the tracking control reference signal is recorded in the recording track of the video signal. The tracking control reference signal is disposed substantially on both sides of the recording track, and the tracking control reference signal is intermittently recorded in a portion corresponding to the horizontal retrace period of the video signal. A video signal recording and reproducing method characterized in that the tracking control reference signal is also reproduced, and the video signal is reproduced by the magnetic head whose tracking is controlled by the tracking control signal generated from the reproduced reference signal.