JPH0716239B2 - Video signal recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order.

A Industrial Field B Outline of Invention C Conventional Technology D Problems to be Solved by the Invention E Means for Solving Problems (FIG. 1) F Action G Example G ₁ Video signal recording / reproducing device ( (FIGS. 1 and 2) H Effect of Invention A Field of Industrial Application The present invention uses a rotary head that is displaceable in a direction substantially orthogonal to the scanning direction to a tape running at an arbitrary speed and a standard speed. The video signal is set to 1 so that a tilted track having the same tilt as the tilted track formed on the tape running at
The present invention relates to a video signal recording device that records each field.

B SUMMARY OF THE INVENTION The present invention uses a rotary head that is displaceable in a direction substantially orthogonal to the scanning direction, and allows a tape running at an arbitrary speed to have the same tilt as a tilt track formed on the tape running at a standard speed. 1 video signal to form a tilted track of
A video signal recording apparatus adapted to record a field signal at a time is controlled by switching the recording timing of the video signal according to whether the video signal is recorded in a field unit or a frame unit. It is possible to record without omission.

C Prior Art Hereinafter, a video signal recording apparatus of this type proposed by the present applicant will be described with reference to FIG. 4 (Japanese Patent Application No. 58-10112 and Japanese Patent Application No. 57-189859). reference). Where S
A video signal recording / reproducing apparatus made based on an MPTE type C type VTR will be described.

(1) is a magnetic tape, which is wound around the tape guide drum (2) at an angle of Ω and guided. A control signal is recorded in advance on the side edge of the tape (1). Tape (1)
The winding angle of the tape with respect to the tape guide drum (2) is close to 360 °, and the winding state, that is, the winding inclination and the winding angle are regulated by the pair of inclined guide pins (5) and (6). It

The tape guide drum (2) comprises a rotating upper drum (3) and a fixed lower drum (4). (7a) is a recording / reproducing rotary magnetic head, (7b) is an erasing rotary magnetic head, and these heads (7a) and (7b) are common electric heads such as bimorphs.
By being attached to the rotating upper drum (3) via the mechanical conversion element (8), it can be displaced in a direction substantially orthogonal to the scanning direction. Reference numeral (9) denotes a drum motor for rotationally driving the upper rotating drum (3), which is attached to the drum (3) via a shaft (10). It should be noted that γ indicates the rotation direction of the rotating upper drum (3).

As shown in FIGS. 5 and 6, the heads (7a) and (7b) have ring-shaped cores RCa and RCb, respectively, the former being balanced winding, and the latter being one-sided with coils La and Lb. There is.
The coil Lb is wound around the leg portion of the core RCb away from the head (7a) in order to avoid crosstalk between the erase signal and the recording signal. The gap Ga of the head (7a) is the core
It is located in the center of RCa. Gap of head (7b)
b is one side of the core RCb and is provided near the head (7a). The gap Gb of the head (7b) has an azimuth with respect to the gap Ga of the head (7a).
Wider than Ga. The distance d between the facing portions of the cores RCa and RCb is about 2 mm, which is very close.

Returning to FIG. 4 again, description will be made. (11) is a control magnetic head (winding type magnetic head). (12) is a capstan, and (13) is a capstan motor that rotationally drives the capstan (12). (14) is tape (1)
It is a pinch roller that rolls into contact with the capstan (12) via. The tape (1) is sandwiched between the capstan (12) and the pinch roller (14), and both are rotated, so that the tape (1) is moved at an arbitrary traveling speed according to the rotation speed of the motor (13). You can drive in the α direction. A double capstan system can also be adopted, in which case the tape (1) can be run at any running speed in both forward and reverse directions.

(15) is a time-axis expansion / contraction processing circuit on the recording side, to which an input video signal from an input terminal (16) is supplied. This circuit (16) is a sync separation circuit (15a) for separating a vertical sync signal (60 Hz in the case of the NTSC system) from an input video signal (video signal not subjected to time-axis expansion / contraction processing) supplied to the input terminal (16). ) Is included. Incidentally, this vertical synchronizing signal is a reference synchronizing signal from the synchronizing board, and is obtained at the time of recording and reproducing.

(17) is a servo circuit for the drum motor (9). The drum motor (9) includes signal generators (electrodes (magnetizing magnet wheels) and magnetic heads (magnetic electrodes) that generate frequency signals and phase signals respectively generated by the rotation of the motor (9), that is, the rotating drum (3). A thin film type magnetic flux detecting head), and these signals are supplied to the servo circuit (17). Further, the servo circuit (17) is supplied with a vertical synchronization signal (reference vertical synchronization signal) from the synchronization separation circuit (15a) of the processing circuit (15), and the drum motor (9)
The rotation of the drum motor (9) is controlled by the servo circuit (17) so that each signal from the signal generator of (1) is surely locked to the vertical synchronizing signal. In this case, the rotation of the rotating drum (3) does not fluctuate with the running speed of the tape (1).

Reference numeral (18) is an input terminal, to which a speed command signal for instructing the running speed of the tape (1) is supplied, which is generated when the operator operates a push button or the like of the speed controller. The speed command signal from the input terminal (18) is supplied to the microprocessor (19) and the tape running speed control pulse generator (20) to control each of them. The pulse from the pulse generator (20) is supplied to the servo circuit (21) for the capstan motor (13). In addition, the microprocessor (1
The control signal from 9) is supplied to the pulse generator (20).

Reference numeral (22) is a position detector for detecting the running position of the tape (1) (running position in the longitudinal direction of the tape), and a reproduction control signal from the control magnetic head (11),
The capstan motor (13) is provided with a motor (13),
That is, its frequency from a frequency signal generator {consisting of a magnetic pole (for example, a magnetizing magnet wheel with 96 poles for one round) and a magnetic head (for example, a thin film type magnetic flux detection head)} that generates a frequency signal according to the rotation of the capstan (12). And the signal are supplied to the position detection circuit (22). This position detector (2
In 2), the rough traveling position of the tape (1) is detected by the control signal, and the fine traveling position of the tape (1) is detected by the frequency signal. Position detector (2
The position detection signal from 2) is supplied to the microprocessor (19) and the servo circuit (21).

Further, the time-axis expansion / contraction processing circuit (15) on the recording side receives the frequency signal from the frequency signal generator of the capstan motor (13) and performs time-axis expansion / contraction processing of the video signal according to the frequency, The phase of the entire video signal is corrected based on the error signal from the capstan servo circuit (21).

SW ₁ , SW ₂ and SW ₃ are recording / reproducing changeover switches, each of which has a movable contact m and recording and reproducing side fixed contacts p and r, which are interlocked and switched.

(23) applies a drive signal from the output terminal (24) to the electro-mechanical conversion element (8) to which the rotary magnetic heads (7a) and (7b) are attached, and sets the head (7) in the scanning direction. It is a head displacement drive circuit that displaces in a substantially orthogonal direction. This head displacement drive circuit (23) is a drum servo circuit (1
The flyback pulse is received from 7), and based on this, a sawtooth wave drive signal with a fixed phase is formed. Further, in the head displacement drive circuit (23), the capstan motor (13) obtained via the switch SW ₁ at the time of recording
Based on the frequency of the frequency signal from the frequency signal generator, the frequency of the horizontal sync signal from the head displacement control circuit (34), which will be described later, and the tracking error amount of the tracking error signal, which are obtained via the switch SW ₁ during playback. Based on this, the slope of the sawtooth wave drive signal is controlled. Furthermore,
In this head displacement drive circuit (23), based on the error amount of the error signal from the capstan servo circuit (21) obtained via the switch SW ₂ during recording, it is obtained via the switch SW ₂ during reproduction. Head displacement control circuit (3
Based on the phase of the horizontal sync signal from 4), the offset level of the sawtooth wave drive signal is controlled.

Next, the recording timing control circuit (30) will be described.
(25) is an FM modulation / recording amplifier, which receives the video signal from the time axis expansion / contraction processing circuit (15), FM-modulates the video signal, amplifies the FM-modulated video signal, and outputs it through the switch SW ₃ . A recording signal is supplied from the terminal (26) to a recording / reproducing rotary magnetic head (7a) via a rotary transformer (not shown). Further, (37) is an erasing signal generation circuit (oscillator), and an erasing signal (having a frequency slightly lower than twice the FM carrier frequency) from this is output terminal (38).
Is supplied to the erasing rotary magnetic head (7b). FM modulation
The recording amplifier (25) and the erase signal generation circuit (37) are controlled by the gate signal from the gate signal generator (27),
The recording / erasing timing and the recording / erasing cycle are controlled. The gate signal generator (27) is controlled by the microprocessor (19). (28) and (29) are framing discrimination circuits, of which (28) is an input terminal (16)
An odd / even discrimination circuit that receives a video signal from the processing circuit (15) and discriminates the odd / even of the field, and (29) outputs a video signal from the input terminal (16) (processing circuit (15) is also possible). It is a color framing discrimination circuit that receives and discriminates the color framing. Then, these discrimination circuits (2
The discrimination outputs 8) and (29) are supplied to the microprocessor (19). In addition, this microprocessor (19) has
A vertical sync signal (reference vertical sync signal) is supplied from the sync separation circuit (15a) of the time axis expansion / contraction processing circuit (15).
(39) is the control head (11) during playback mode
A detection circuit for detecting the data from the control signal (including color framing or field odd / even data corresponding to each slanted track) is supplied to the microprocessor (19).

Also, the reproduction signal from the recording / reproducing rotary magnetic head (7a) is supplied to the reproduction amplifying / FM demodulator (31) via the switch SW ₃ and is amplified, and the FM-modulated video signal is demodulated. , A video signal is obtained, which is supplied to the time expansion / contraction processing circuit (32) on the reproduction side, corrected on the time axis, and output to the output terminal (33).

Further, the horizontal synchronizing signal in the color video signal from the reproduction amplifier / FM demodulator (31) is supplied to the head displacement control circuit (34). Further, the head displacement control circuit (34) includes an envelope signal and an electromechanical conversion element of a reproduction signal (high frequency signal) of the recording / reproducing rotary magnetic head (7a) from the input terminals (35) and (36). Strain detection signals from mechanical-electrical conversion elements (strain gauges) (not shown) attached to the (bimorph) (8) are respectively supplied.

Next, the recording operation of the video signal recording / reproducing apparatus of FIG. 4 will be described with reference to FIG. Each movable contact of the switches SW _{1 to} SW ₃ is switched to the recording side fixed contact r. Consider a case where the running speed of the tape (1) is set lower than the standard speed Sn, that is, 1 / m of the standard speed Sn, and the video signal from the input terminal (16) is recorded on the tape (1). .
In FIG. 7, (1) indicates the same magnetic tape as in FIG. 4, and CTL indicates the control signal recorded on the tape (1) in advance at equal intervals. T is tape (1) at standard speed
The inclined track (shown by the solid line) by the magnetic head when traveling at Sn is shown, and T'is the inclined track when the tape (1) is traveling at 1 / m of the standard speed Sn (indicated by the broken line). Show).

Then, in this video signal recording and reproducing device (VTR),
When the running speed of the tape (1) is (1 / m) Sn, the tape (1) is provided with a tilted track T having the same tilt and the same length as the tilted track when the tape (1) is running at the standard speed Sn. ) Allow the video signal to be recorded as formed above. In FIG. 7, α indicates the running direction of the tape (1) and β indicates the scanning direction of the head (7).

Therefore, a speed command signal indicating that the running speed of the tape (1) is (1 / m) Sn (m can be arbitrarily selected) is supplied to the input terminal (18). This way, pulse generator (20)
Generates a pulse having a frequency 1 / m times the frequency Fn of the pulse generated when the tape (1) is at the standard running speed Sn, and this is supplied to the capstan servo circuit (21). Thus, the tape (1) is driven by the capstan (12) and the pinch roller (14) so that the tape (1) continuously travels at a speed of (1 / m) Sn. The running speed (1 / m) Sn of the tape (1) does not change unless the microprocessor (19) supplies a control signal to the pulse generator (20) to change the speed.

In this case, the capstan is driven and controlled within a certain tape speed range lower than the standard recording / reproducing tape speed, whereby the tape (1) is moved from the position near one recorded track to the position of the next adjacent recording scheduled track. To perform. At this time, the tape (1) moves to the adjacent track position in a short time, and the tape speed before and after reaching the adjacent track position is standard without overshooting or overshooting the standard track interval. Capstan control that targets such tape speed is performed so that it is possible to have a constant tape speed (including static) that is sufficiently lower than the recording / reproducing tape speed.

Further, in the time axis expansion / contraction processing circuit (15), when the tape (1) is running at a low speed or when the running is stopped, the unit signal of the input video signal, that is, one field, is exactly recorded on the inclined track T of FIG. , The input video signal is expanded and the control track CTL on the tape (1) is
The video expanded on the basis of the error signal from the capstan servo circuit (21) so that the arrival position of the tilted track T with respect to the reference point and the timing of the video signal to be recorded on the tilted track T coincide with each other. The phase of the signal is controlled.

Further, the head displacement drive circuit (23) includes heads (7a), (7
The electro-mechanical conversion element is controlled by the drum servo circuit (17), the frequency signal generator of the capstan motor (13) and the capstan servo circuit (21) so that b) surely scans the inclined track T. A drive signal is supplied to (8). When the head (7a) scans an inclined track T to record a video signal of a certain field and then scans the adjacent inclined track T to record a video signal of another field, the head (7a) The pulse generator (20) is controlled by the microprocessor (19) only when the tilt track T cannot be scanned by the displacement of (7b) alone. 1 / m) Sn slightly changed, head (7a), (7b)
Allows the desired tilt track T to be scanned. Therefore, the traveling of the tape (1) is controlled by the displacement of the heads (7a), (7b) within a possible range so that the tape (1) can surely scan a predetermined inclined track T.

In the FM modulation / recording amplifier (25), on / off of the recording amplifier is controlled by a gate signal from a gate signal generator (27) (which is controlled by a microprocessor (19)) to expand / contract the time axis. The supply / non-supply of the time-axis stretched video signal from the processing circuit (15) to the recording / reproducing head (7a) is controlled. That is, among the video signal from the processing circuit (15), a video signal of an integer field per field close to m is supplied to the head (7a) through the switch SW ₃ is extracted by one field minutes.

When a color video signal is to be recorded on the tape (1), the color framing discriminating circuit (29) is arranged so that the color video signal is sequentially recorded on each inclined track T while maintaining the continuity of the color framing. ), The video signal from the processing circuit (15) is selected on a field-by-field basis.

Further, when a monochrome video signal is to be recorded on the tape (1), the monochrome video signal is sequentially stored in each inclined track T while maintaining the odd-even continuity of the field.
As described in (1), the video signal from the processing circuit (15) is selected in field units based on the discrimination output of the odd-even discrimination circuit (28).

FIGS. 8 and 9 show the head height vector P even if the tape speed and position at the moment of recording are arbitrary.
FIG. 6 is a vector diagram showing that it is possible to restore and record in a regular pattern by highly controlling the signal phase vector Ψ.

The standard recording speed vector vr is the head scanning speed vector vh.
And the tape velocity vector vt. If there is an arbitrary recording speed vector vr at an arbitrary position, a vector (vr) can be obtained by adding the speed correction vector Δf to this.

On the other hand, the positional deviation vector ΔΨ on the tape (1) can be corrected by combining the video signal phase component vector (ΔΨ) and the track vertical direction movable head displacement vector (ΔP).

Further, as can be seen from FIG. 9, the above-mentioned Δf can be obtained by combining the time derivative values of ΔP and ΔΨ. Where Δf is Δ
f = a + b. However, a = Is.

Thus, instead of the inclined track T'at a certain speed of the tape (1) (lower than the standard speed), the same inclined track T at that speed as at the standard speed can be formed on the tape (1). it can.

Next, the frictional force of the tape running system will be described. This problem undermines the controllability of tape tension and tape guiding, especially when the tape is stationary or running backwards.

For example, assume that the tape is running in the forward direction in the SMPTE type C type VTR. At this time, the tension T (θ) distribution on the drum can be calculated as follows.

However, T ₀ : Tension at tape entrance μ: Friction coefficient of fixed part θ _max : Full winding angle Tension T at the moment the tape runs in the opposite direction
The distribution of (θ) changes completely as shown in the following equation.

What then happens to the tension distribution from the moment the tape stands still to the time it runs in the opposite direction? To put it simply, it can be said that it is a state capable of producing innumerable distribution curves. That is, when the elastic body in contact with the solid friction surface is strained by the frictional force, its strain distribution is a free distribution state within the range of the maximum strain gradient determined by the equivalent frictional force and the equivalent elastic modulus. This is because it has the property of saving.

For example, the distribution at the moment when the tape stands still belongs to either of the above distribution calculation formulas. However, if one or both of the tension on the inlet side or the outlet side of the tape drum changes with the stop of the tape running,
How will the tension distribution on the way change, but
A new distribution curve that continuously connects the given inlet and outlet tensions cannot be easily obtained. It is appropriate to think of this as, for example, that a corner of a sand pile made of free-flowing sand collapses and another inclined portion is generated, and as a result, the tension on both sides can be dealt with.

That is, a continuum that retains its shape with solid friction exhibits just typical hysteresis (history) development, which can have infinite uncertainty (diversity) in its shape as a continuum. This is similar to the above-mentioned shape of the sand pile showing infinite history. It is also considered that the hysteresis is canceled by a slight external vibration disturbance or the like, and eventually returns to the ground state in such a manner that the sand pile is flattened.

Therefore, if the tension distribution on the drum surface that is completely equal to that at the standard speed recording is desired, the following conditions must be observed. That is, the direction of friction of the tape should not be changed during or immediately before recording. To ensure this, recording must be performed while the tape is running at a low speed, or the tape must be gradually stopped without overshooting and recording should be performed immediately before tension relaxation occurs.

By the way, it is generally thought that normal recording is unlikely to be possible even when trying to record a signal on a tape during continuous low speed motion, and it was usually thought to choose either standard speed or completely stationary. Conventionally, the idea of recording while moving such a tape at a low speed has not been proposed yet, but this is made possible by the above-mentioned video signal recording / reproducing apparatus proposed by the applicant.

Note that the tape used for recording is not limited to the stationary or constant low speed running, but may be the intermittent running. In this case, only a single block section in one field, frame or other signal sequence is recorded in the flow of the recording target signal.
Stop recording immediately after recording a single block, or
Provide at least a rest section. Immediately after the recording of at least a series of signal blocks, the command to stop the capstan drive is immediately issued, which causes the tape to be stopped at least for a distance shorter than the track pitch at the standard speed continuous recording, and at the position, the next Wait for track recording command. After waiting at this waiting position, the next track is recorded by the next recording command.

Next, the operation of the apparatus shown in FIG. 4 when a part of the video signal recorded on the recorded tape is rewritten to a new video signal will be described. This recorded tape is the fourth
With the device shown in the figure, even when the video signal is recorded as described above when the tape is running at low speed or in a stationary state,
A conventional SMPTE type C type VTR may be used to record the video signal normally at the standard speed running of the tape.

First, the movable contact m of the switches SW _{1 to} SW ₃ is switched to the playback side fixed setting p, the playback mode is set, the still image of the recorded tape video signal is sequentially played back in frame units, and the video signal to be rewritten is selected. decide. In this case, the intermittent drive command signal of the tape is supplied to the input terminal (18), and the intermittent pulse is generated by the pulse generator (20), and the tape (1) is intermittent in every two fields, that is, every two tracks. Be driven.

In this case, the head drive circuit (23) includes the head (7a),
(7b) is controlled by the drum servo circuit (17) and the head displacement control circuit (34) so that the inclined track T on which the video signal is recorded is surely scanned in the stopped state of the tape (1). Drive the mechanical conversion element (8).

The reproduction signal from the head (7a) is supplied to the reproduction amplification / FM demodulator (31) via the switch SW ₃ to amplify and FM demodulate the FM-modulated video signal, and then the time axis expansion / contraction processing circuit ( The image is supplied to an output terminal (33) and is output to an output terminal (33) and is received by a monitor receiver (not shown).

In this way, when a portion of the video signal recorded on the recorded tape to be rewritten, for example, a video signal for one frame is determined, the tape (1) is stopped and the recording mode is switched to. , The movable contacts m of the switches SW _{1 to} SW ₃ are switched to the fixed contacts r on the recording side. The operation of the apparatus shown in FIG. 1 in the recording mode is as described above. However, here, the video signal of the frame to be rewritten must be erased before recording. Therefore, the erasing signal generating circuit (37) generates an erasing signal at substantially the same timing as the recording signal and supplies it to the erasing head (7b).

Also, the recording / reproducing head (7a) and the erasing head (7b) are
With the tape (1) stopped running, the electro-mechanical conversion element (8) sequentially scans the two inclined tracks T on which one frame of the video signal to be rewritten is recorded. The video signal for the frame is erased and recorded. During this time, the head displacement drive circuit (2
From 3), a head drive signal having a constant tilt is generated over the recording period of the video signal for one frame, and this is supplied to the electro-mechanical conversion element (8).

When a color video signal is to be rewritten and recorded on the recorded tape (1), the detection circuit (so that the color video signal is sequentially recorded on each inclined track T while maintaining the continuity of color framing. The video signal from the processing circuit (15) is selected in field units based on the color framing data of the recorded video signal detected in 39).

Further, when a monochrome video signal is to be recorded on the tape (1), the monochrome video signal is sequentially stored in each inclined track T while maintaining the odd-even continuity of the field.
Detected by the detection circuit (39) as recorded in
The video signal from the processing circuit (15) is selected in field units based on the odd-even data of the field of the recorded video signal.

After rewriting and recording the video signal of the recorded tape (1), if the tape (1) is stopped and the mode is switched to the reproduction mode again, the rewritten and recorded video signal is reproduced as a still image and checked. be able to. It goes without saying that the rewritten and recorded video signal can be rewritten and recorded many times.

The number of rotary heads (for example, two), the winding angle of the tape with respect to the tape guide drum (for example, 180 °), and the like are not limited to the above examples, but are arbitrary.

Also, the recording and reproducing rotary magnetic heads may be separate heads instead of being combined. In this case, the electro-mechanical conversion elements to which these heads are attached may be common or separate.

The video signal recording / reproducing apparatus described above is suitable for use in creating a master tape of a video disc, creating an animation image, creating a still image file, and the like.

D Problems to be Solved by the Invention Problems with the video signal recording apparatus described with reference to FIG. 4 will be described with reference to FIG. As shown in FIG. 3A, when the tape is run at a speed lower than the standard running speed, the adjacent inclined tracks formed by the rotary heads on the tape are A and B, respectively, at the standard running speed. The adjacent inclined tracks on the tape are designated as X and Y, respectively. In this case, the inclined tracks A, X and B, Y respectively intersect at their midpoints.

Run the tape at a speed lower than the standard running speed,
In order to record a video signal on the inclined tracks X and Y of the tape, the rotary head must be displaced by an electro-mechanical conversion element such as a bimorph.

Therefore, when the video signal subjected to the time-axis expansion / contraction processing is supplied to the rotary head one field at a time and recorded on the tape so as to form the inclined tracks X and Y one by one, each rotary head is slightly displaced. Then, the tilted tracks A and B are overlapped with the tilted tracks X and Y, respectively, and the video signals for one field may be recorded respectively. As for the inclined track X, the shaded portion is the portion where the video signal is actually recorded and the white portion is the recording loss portion, but the recording loss portion is relatively small.

However, when the video signal subjected to the time axis expansion / contraction processing is supplied to the rotary head one frame at a time and recorded on the tape so that two inclined tracks X and Y are sequentially formed,
First, the rotary head is slightly displaced so that the tilted track A
Is recorded on the tilted track X, the video signal for the first one field is recorded, and then the rotary head is further displaced in the same direction so that the tilted track A overlaps the tilted track Y. The video signal for one field is recorded. In the inclined tracks X and Y, the shaded portion is the portion where the video signal is recorded, and the white portion is the recording missing portion. The inclined track X has few recording missing portions, but the inclined track Y has many recording missing portions. For this reason, the image quality of the reproduced video signal from the tilted track Y is deteriorated, and when the vertical synchronizing signal is lost, synchronization disorder occurs on the reproduced screen.

Incidentally, FIG. 3B shows a control signal recorded on the side edge of the tape, and FIG. 3C shows a tape position signal (triangular wave signal) based on the control signal. Relative levels vary between 0 and 100 between control signals. Inclined track X, Y
Are formed on the tape in a one-to-one correspondence with control signals.

In view of the above-mentioned point, the present invention uses a rotary head that is displaceable in a direction substantially orthogonal to the scanning direction, and a tape running at a standard running speed on a tape running at an arbitrary running speed lower than the standard running speed. In order to form a tilted track having the same tilt as the tilted track formed above, a video signal subjected to time-axis expansion / contraction processing is used for one field by the rotary head with reference to the address signal prerecorded on the side edge of the tape. In the video signal recording apparatus adapted to record each time, when the video signal subjected to the time axis expansion / contraction processing is supplied to the rotary head for each field and recorded on the tape so as to form each inclined track, When the video signal that has undergone axis expansion / contraction processing is supplied to the rotary head one frame at a time and recorded on tape so that two inclined tracks are sequentially formed. In either case, it is possible to reduce the recording missing portion of the video signal is intended to provide what may be to reduce the image quality degradation, risk of vertical synchronization disturbance of reproduction screen.

E Means for Solving the Problems The present invention provides a single rotary head (7a) provided on the rotary drum (3) of a tape guide drum (2) comprising a rotary drum (3) and a fixed drum (4). ), A drum motor (9) for driving the rotary drum (3), a drum servo circuit (17) for supplying a servo signal synchronized with the vertical synchronizing signal of the input video signal to the drum motor (9), and a rotary head ( An electro-mechanical conversion element (8) for displacing 7a) in a direction substantially orthogonal to the scanning direction, and a head displacement drive circuit (23) for supplying a drive signal to the electro-mechanical conversion element (8).
And a time axis stretch processing circuit (15) for subjecting the input video signal to the time axis stretch processing, and the time axis stretch processing video signal from the time axis stretch processing circuit (15) is gated to the rotary head (7a). A recording circuit (25) to be supplied, an address head (11) for reproducing an address signal previously recorded on a side edge of the tape (1), a capstan (12) for running the tape, and the capstan ( Based on the reproduction address signal from the capstan motor (13) for driving 12), the address head (11), the frequency signal corresponding to the rotation of the capstan motor (13), and the traveling speed control signal,
A capstan servo circuit (21) for supplying a servo signal to a capstan motor (13), and a head displacement drive circuit (23), a time axis expansion / contraction processing circuit (15), according to a specified traveling speed. By controlling the recording circuit (25) and the capstan servo circuit (21), on the tape (1) running at the specified running speed lower than the standard running speed, and on the tape (1) running at the standard running speed. In order to form an inclined track having the same inclination as the formed inclined track, the video signal subjected to the time-axis expansion / contraction processing with the address signal pre-recorded on the side edge of the tape (1) as a reference is used for the rotary head (7
In the video signal recording apparatus configured to record one field at a time according to a), the video signal subjected to the time axis expansion / contraction processing is supplied to the rotary head (7a) through the recording circuit (25) for each field, and the video signals are recorded one by one. When recording on the tape (1) so as to form a slanted track, the recording of one field of the video signal subjected to the time-axis expansion / contraction processing is started from the reproduction point of the reproduction address signal, and the video subjected to the time-axis expansion / contraction processing is performed. When signals are supplied to the rotary head (7a) through the recording circuit (25) one frame at a time and recorded on the tape so that two inclined tracks are sequentially formed, the time between adjacent reproduction address signals is reproduced. Temporal
Record one frame of the time-axis stretched video signal so that the point of 1/2 coincides with the half-point of time of one frame of the time-axis stretched video signal. Further, a recording control means (4) for controlling the head displacement drive circuit (23), the recording circuit (25) and the capstan servo circuit (21) to switch the recording timing of the video signal.
4) A video signal recording device characterized by being provided with.

According to the present invention, the video signal subjected to the time-axis expansion / contraction processing is supplied to the rotary head (7a) through the recording circuit (25) one field at a time so that each tape is formed so as to form one inclined track. When recording in 1), recording of one field of the video signal subjected to time-axis expansion / contraction processing is started from the reproduction time point of the reproduction address signal, and the video signal subjected to time-axis expansion / contraction processing is recorded for each frame ( twenty five)
When feeding to the rotary head (7a) through the tape and recording on the tape so that two inclined tracks are sequentially formed,
The time axis expansion / contraction processing is performed so that the time half of the time between the reproduction time points of the adjacent reproduction address signals coincides with the time 1/2 of the time of one frame of the time axis expansion / contraction processed video signal. The recording timing of the video signal is switched and controlled so as to record one frame of the video signal.

G Embodiment G ₁ Video signal recording / reproducing apparatus An example of a video signal recording / reproducing apparatus to which the present invention is applied will be described below with reference to FIG.
Portions corresponding to those in the figure are denoted by the same reference numerals and redundant description will be omitted. Reference numeral (44) denotes a recording control means for switching and controlling the recording timing, which will be described below. The tape position signal from the tape running position detector (22) (see A and C in Fig. 2) and the frequency signal from the frequency generator of the capstan motor (13) are converted into a frequency-voltage converter (F / V) ( The frequency-corresponding voltage obtained by being supplied to the circuit 40) is supplied to the A / D converter (41) for A / D conversion separately. The digital tape position signal and the frequency compatible digital voltage (each parallel signal) obtained from the A / D converter (41) and the 1 field unit / 1 frame unit recording switching signal from the input terminal (43) are used as address signals. PROM (Programmable Read Only Memory)
(42) to obtain a recording timing setting signal (recording start and end timing signal), and this signal is supplied to the microprocessor (19) to generate a gate signal generation circuit (27).
To control. Thus, the timing of supplying the recording signal from the FM modulation / recording amplifier (25) to the rotary head (7a) is controlled.

Next, the recording timing of field unit recording and frame unit recording will be described with reference to FIG. Second
In Fig. A, the relative voltage corresponding to frequency is 20 as shown in Fig. 2B.
The following shows the recording timing of field unit recording and frame unit recording for the tape position signal when the tape traveling speed is 2/30 times the standard traveling speed. During field unit recording, that is, the video signal subjected to the time-axis expansion / contraction processing by the time-axis expansion / contraction processing circuit (15) is FM modulation / recording amplifier (25).
When the video signal is a monochrome video signal so that the color framing of 4 fields is maintained when the video signal is a color video signal and the FM modulation and amplification are performed. , So that the odd and even alternation of the field is maintained,
When the magnetic tape (1) is gated and supplied to the rotary magnetic head (7a) for recording one field at a time, the recording is performed on the magnetic tape (1), that is, at the reproduction time of the reproduction address signal, that is, the tape. When the relative level of the position signal (triangular wave signal whose relative level changes in the range of 0 to 100) becomes 0 (100), recording of one field of the video signal subjected to the time axis expansion / contraction processing is started. The recording period is the period when the relative level of the tape position signal is 0-20.

In addition, when recording on a frame-by-frame basis, that is, the video signal that has been time-axis stretched by the time-axis stretch processing circuit (15)
The signal is supplied to the modulation / recording amplifier (25) to be FM-modulated and amplified, and at the same time, one frame at a time (when the video signal is a color video signal, the video signal is changed so as to maintain the color framing of 4 fields). If it is a monochrome video signal, it is gated by one frame so that the evenness of fields is maintained.
When the data is supplied to the rotary magnetic head (7a) and recorded on the magnetic tape (1) so as to form two inclined tracks, one-half of the time between the reproduction time points of the adjacent reproduction address signals.
The second time point, that is, the time point when the relative level of the tape position signal becomes 50, coincides with the time axis expansion / contraction processing so that it coincides with the time point of 1/2 of one frame of the time axis expansion / contraction processed video signal. One frame of the recorded video signal is recorded. The recording period is the period when the relative level of the tape position signal is 30 to 70.

FIG. 2C shows that the frequency-corresponding relative voltage is as shown in FIG. 2D.
The following shows the recording timing of field unit recording and frame unit recording for the tape position signal when the tape traveling speed is 10 (1/30 times the standard traveling speed). Although a detailed description of the recording timing in this case is omitted, the recording period during the field unit recording is a period in which the level of the tape position signal is 0 to 10, and the recording period during the frame unit recording is the level of the tape position signal. Is a period of 40 to 60.

Next, frame unit recording will be described with reference to FIG. As shown in FIG. 3A, each of the adjacent inclined tracks formed on the tape running at the standard running speed is
Let M and N. During frame unit recording, the center of the inclined track C formed by the rotary head (7a) on the tape (1) when the magnetic tape (1) is run at a certain running speed lower than the standard running speed, Inclined track
The recording timing is selected so that it comes to the center between the centers of M and N, and the video signal subjected to the time axis expansion / contraction processing is supplied to the rotary head (7a) one frame at a time, and two inclined tracks are provided. Recording is performed on the tape so that M and N are sequentially formed. When recording the first one field of the video signal, the rotary head (7a) is displaced so that the tilted track C overlaps the tilted track M, and subsequently the video signal of the next one field is recorded. At this time, the rotary head (7a) is displaced in the opposite direction so that the tilted track C overlaps the tilted track N.

By doing so, the displacement amount (referenced to the case of scanning the tilted track C when the rotary head (7a) that scans the tilted track C is displaced so as to scan the tilted tracks M and N on both sides thereof ( Is larger than the displacement amount when the rotary head that scans the inclined track A is displaced to scan the inclined track X, but the rotary head that scans the inclined track A is displaced to scan the inclined track Y. It becomes smaller than the displacement amount when it is made. Therefore, by selecting the recording timing so that the rotary head (7a) is displaced so that the tilted track C overlaps the tilted tracks M and N on both sides of the tilted track A during the frame unit recording, the tilted track A is tilted as in the conventional case. Compared to the case of recording so as to overlap the
There is less risk of image quality degradation on the playback screen and vertical sync disturbance due to loss of the vertical sync signal.

According to the present invention described above, according to the present invention, a single rotary head provided on a rotary drum and a fixed drum of the tape guide drum, a drum motor for driving the rotary drum, and an input video signal A drum servo circuit that supplies a servo signal synchronized with a vertical synchronization signal to a drum motor, an electro-mechanical conversion element that displaces the rotary head in a direction substantially orthogonal to the scanning direction, and a drive signal that is supplied to the electro-mechanical conversion element. Head displacement driving circuit, time axis expansion / contraction processing circuit for expanding / compressing the input video signal in time axis, and recording circuit for supplying the time axis expansion / compression processed video signal from the time axis expansion / compression processing circuit to the rotary head. , An address head for reproducing an address signal recorded in advance on the side edge of the tape, a capstan for running the tape, and a capstan for the capstan. A capstan motor that drives the stun, a capstan servo circuit that supplies a servo signal to the capstan motor based on a reproduction address signal from the address head, a frequency signal corresponding to the rotation of the capstan motor, and a traveling speed control signal. And a head displacement drive circuit, a time axis expansion / contraction processing circuit, according to the specified traveling speed.
By controlling the recording circuit and the capstan servo circuit, an inclined track having the same inclination as the inclined track formed on the tape running at the standard running speed is formed on the tape running at the specified running speed lower than the standard running speed. As described above, in the video signal recording apparatus in which the video signal subjected to the time-axis expansion / contraction processing is recorded by the rotary head one field at a time based on the address signal pre-recorded on the side edge of the tape. When the expanded / contracted video signal is supplied to the rotary head through the recording circuit for each field and recorded on the tape so as to form each inclined track, the time-axis expansion / contraction process is performed from the reproduction point of the reproduction address signal. Recording of one field of the video signal is started, and the video signal subjected to the time axis expansion / contraction processing is When the tape is supplied to the rotary head through the recording circuit so that two inclined tracks are sequentially formed, half of the time between the reproduction time points of the adjacent reproduction address signals is expanded / contracted on the time axis. The head displacement drive circuit, the recording circuit, and the recording circuit are arranged so that the recording of one frame of the video signal subjected to the time axis expansion / contraction processing is performed so as to coincide with the time point of 1/2 of the one frame of the processed video signal. Since the recording control means for controlling the recording timing of the video signal by controlling the capstan servo circuit is provided, the video signal subjected to the time axis expansion / contraction processing is supplied to the rotary head through the gate circuit for each field, and When recording on a tape so as to form a tilted track for each book, and when the video signal subjected to the time axis expansion / contraction processing is supplied to the rotary head through the gate circuit for each frame. Thus, in any case of recording on the tape so that two inclined tracks are sequentially formed, the recording missing portion of the video signal can be reduced, and the deterioration of the image quality of the reproduction screen and the possibility of synchronization disorder are reduced. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a video signal recording / reproducing apparatus to which the present invention is applied, FIG. 2 is a time chart used for explaining the recording timing of the present invention, and FIG. 3 is a time chart used for explaining a recording pattern. FIG. 4 is a block diagram showing a video signal recording (reproducing) device proposed previously.
5 and 6 are plan and front views of the head, FIGS. 7 and 8 are diagrams showing recording patterns, and FIG. 9 is a vector diagram for explaining the recording patterns. (1) is a tape, (7a) is a rotary head, and (44) is a recording control means.

Claims (1)

[Claims] 1. A single rotary head provided on a rotary drum, a drum motor for driving the rotary drum, and a drum servo circuit for supplying a servo signal synchronized with a vertical synchronizing signal of an input video signal to the drum motor. An electro-mechanical conversion element that displaces the rotary head in a direction substantially orthogonal to the scanning direction, a head displacement drive circuit that supplies a drive signal to the electro-mechanical conversion element, and a time-axis expansion / contraction process for the input video signal. A time axis expansion / contraction processing circuit, a recording circuit for supplying the time axis expansion / contraction processing video signal from the time axis expansion / contraction processing circuit to the rotary head, and an address previously recorded on the side edge of the tape. An address head for reproducing a signal, a capstan for running the tape, a capstan motor for driving the capstan, and the address. A capstan servo circuit for supplying a servo signal to the capstan motor on the basis of a reproduction address signal from the scanning head, a frequency signal corresponding to the rotation of the capstan motor, and a traveling speed control signal. According to the running speed, the head displacement drive circuit, the time axis expansion / contraction processing circuit, the recording circuit and the capstan servo circuit are controlled to run at the specified running speed lower than the standard running speed. above,
The time axis expansion / contraction processing is performed on the basis of the address signal previously recorded on the side edge of the tape so that an inclined track having the same inclination as the inclined track formed on the tape traveling at the standard traveling speed is formed. In the video signal recording apparatus configured to record the video signal for each field by the rotary head, the video signal subjected to the time axis expansion / contraction processing is supplied to the rotary head for each field through the recording circuit,
When recording on the tape so as to form one inclined track at a time, the recording of one field of the video signal subjected to the time axis expansion / contraction processing is started from the reproduction point of the reproduction address signal, and the time axis expansion / contraction is performed. When the processed video signal is supplied to the rotary head through the recording circuit one frame at a time and is recorded on the tape so that two inclined tracks are sequentially formed, the reproduction time between adjacent reproduction address signals is increased. So that the half point of the time corresponds to the half point of the time of one frame of the video signal subjected to the time axis expansion / contraction processing, In order to perform recording, the head displacement drive circuit, the recording circuit, and the capstan servo circuit are controlled to switch the recording timing of the video signal. Video signal recording apparatus characterized in that a control means.