JPS6242556B2 - - Google Patents

Description

[Detailed Description of the Invention] When recording a video signal on a magnetic tape by sequentially forming diagonal magnetic tracks for each unit time, and reproducing the video signal from this, a normal VTR (video tape recorder) Recording and playback are performed while running continuously.

In this normal VTR, when performing normal playback, the scanning locus of the rotating head has the same inclination angle as the recording track, and the rotating head correctly scans the recording track, but during slow motion playback, still playback, and rewind playback. In this case, the inclination angle of the scanning locus of the rotary head is different from the inclination angle of the recording track, and the rotary head scans across a plurality of tracks. Therefore, if a guard band is formed between recording tracks,
Guard band noise occurs in the reproduced signal, and
Even in the absence of a guard band, the head scans across a plurality of tracks, which has the disadvantage that a good reproduced image cannot be obtained.

Therefore, a recording/playback device has been developed that eliminates the above drawbacks by ensuring that the inclination angle of the scanning locus of the rotary head remains the same during slow motion playback, still playback, and rewind playback as during normal playback. it was thought.

Figure 1 shows an example of the configuration, which consists of two tape running systems, a first tape running system 1 and a second tape running system 2, and when the tape in one running system stops. Even when the tape is stopped, the tape on the other running system is transferred, and recording and playback are performed while the tape is stopped.

The first tape running system 1 has a supply reel 11, a rotary head device 12, a capstan 13, and a take-up reel 14. It is wound once around the entire circumference in an α-shape, and is then wound around a capstan 13 as shown in the figure, and then wound onto a take-up reel 14.

The second tape running system 2 includes a supply reel 21, a rotary head device 22, a capstan 23, and a take-up reel 24. It is wound once in an α-shape around the entire circumference of the guide drum 25 , passed around the capstan 23 , and wound onto the take-up reel 24 .

Here, the tape winding portions of the capstans 13 and 23 are cylindrical rollers, and the outer periphery of this roller is provided with a rubber lining, and a large frictional force is generated between this and the tape. The tape is transported by force. Further, the capstans 13 and 23 are connected to the motor 1.
3M and 23M are intermittently driven to be intermittently rotationally driven.

5 and 6 are accumulators, respectively, for temporarily storing slack in the magnetic tapes 3 and 4 by vacuum suction. Through holes 7 and 8 having a rectangular cross section are formed in the accumulators 5 and 6, and the insides of these through holes 7 and 8 are vacuumed by a vacuum pump (not shown) through pipes 9 and 10. The loose tapes 3 and 4 are stored in the through holes 7 and 8 in a U-shape.

Sensors 16, 26 and 17, 27 for detecting magnetic tape are provided on the sides of these accumulators 5 and 6, respectively.
At 6, 17, 26 and 27, the amount of tape being sucked into the accumulators 5 and 6 is detected. The motor 11M drives the reel 11 based on the detection output of the sensor 16, the motor 21M drives the reel 21 based on the detection output of the sensor 26, the motor 14M drives the reel 14 based on the detection output of the sensor 17, and the motor 14M drives the reel 14 based on the detection output of the sensor 27. The rotation of the motors 24M that drive the reels 24 is controlled by the detection outputs, so that predetermined amounts of the magnetic tapes 3 and 4 are stored in the accumulators 5 and 6, respectively.

The rotary head devices 12 and 22 include, in this example, two rotary heads 18, 19 and 2, respectively.
8 and 29 are provided. In this case, the two heads 18, 19 and 28, 29 are spaced apart from each other by a predetermined distance P in the direction of their rotational axis.

The capstans 13 and 23 described above have motors 13M and 23M that operate for one frame period, for example.
In the NTSC system, the tapes 3 and 4 are alternately rotated by being driven intermittently every 1/30 seconds, thereby feeding the tapes 3 and 4 by a predetermined amount of 2P.

In addition, the rotating heads 18, 19 and 28, 29
are set to rotate at a rate of one rotation per field period, which is 1/60 second in the case of the NTSC system. Furthermore, these rotary heads 18,1
9, 28, and 29 are configured to be sequentially switched every one field period.

Therefore, in this recording/reproducing device, for example,
Recording or reproduction is performed at the timing shown in FIG.

That is, during one frame period _F1 , no feed signal is supplied to the motor 13M and it stops, so the capstan 13 stops and the tape 3
is stationary. (See FIG. 2E. However, the high level portion in the figure indicates the driving state of the motor.) Therefore, recording or reproduction is performed in the tape running system 1.

Then, the head is 18 in the first half of this period _F1 , which is one field period _f1 , and the second half, which is one field period _f2 .
and 19 are switched (see Fig. 2 A and B), and during recording, as shown in Fig. 3,
During the period f ₁ , the head 18 forms one track T ₁ on the tape 3, and during the period f ₂ , the head 19 forms one track T ₂ at a position shifted by P from the track T ₁ in the longitudinal direction of the tape. A video signal for one field is recorded in each field. During reproduction, one field's worth of reproduction signals are extracted from the head 18 during period _f1 and from head 19 during period _f2 .

During this period _F1 , a feed signal is supplied to the motor 23M to rotate the capstan 23 (see FIG. 2F), and the tape 4 is fed by 2P. In this case, the time required to transfer the tape 4 is made shorter than the time for one frame, and the time required for transferring the tape 4 is made shorter than the time for one frame.
At the beginning of frame period _F2 , the tape 4 is made to be completely stationary.

When the next one-frame period _F2 arrives, the tape 4 of the second tape running system 2 is stationary, so recording or reproduction is performed in this second tape running system 2. That is, similarly to the first tape running system 1, the heads 28 and 29 are switched between the first half of the period _F2 , the one-field period _f3 , and the second half, the one-field period _f4 (see Fig. 2, C and D). ), during recording, as shown in FIG. 3, a track T3 is formed on the tape ₄ by the head 28 in a period _f3 , and a track _T4 is formed by the head 29 in a period _f4 . The video signal for the field is recorded, and during playback, the playback signal is taken out from the head 28 in a period _f3 and from the head 29 in a period _f4 .

At this time, during this period _F2 , the motor 13M of the first tape running system 1 is driven, the capstan 13 is rotated, and the tape 3 is fed by a predetermined amount 2P.

The above operations are repeated sequentially to record or play back while the tape is running.
Recording or playback is performed in the same way as a VTR.

According to this recording and reproducing apparatus, since recording and reproduction are always performed on a tape that is in a stationary state, the heads 18, 19, 28,
The inclination angle at which the tape 29 scans the tapes 3 and 4 is constant and equal to the inclination angle of the recording track.
The disadvantages of this can be prevented.

By the way, as mentioned above, in order to perform playback without generating guard band noise, it is necessary to control the head to correctly scan the recording track (just tracking) during playback. In the recording and reproducing apparatus described above, the tape must be controlled so that the tape is stopped at a position where the head correctly scans the recording track.

However, in the case of the above-mentioned recording and reproducing apparatus, the tape is fed by using the frictional force between the capstans 13 and 23 and the tape, so the tape is fed from the same tape stop position using the same feeding signal as when recording. Even if the tape is transported, there is a drawback that the tape does not always stop at the same position at the time of recording due to slipping or the like.

In view of the above-mentioned drawbacks, the present invention provides a recording and reproducing apparatus such as the one described above, by controlling the amount of tape feed during reproduction so that the tape stop position is adjusted so that the head scans the recording track correctly. The aim is to provide a product that is positioned in a comfortable manner.

An example of a recording/reproducing apparatus according to the present invention will be explained below with reference to FIGS. 4 to 7.

In this example, the capstan drive motor 13M
23M and 23M are DC motors, and when a positive voltage is applied to this motor, a rotational torque is generated to feed the tape in the forward direction, and when a negative voltage is applied to it, a rotational torque is generated that causes the tape to be fed in the opposite direction. Rotational torque is generated.

In FIG. 4, 31, 32, 33, and 34 are switches that operate in conjunction with the recording/reproduction changeover switch, and are connected to contact R during recording and to contact P during reproduction.

During recording, the vertical synchronizing signal P _V (FIG. 5A) is separated from the video signal to be recorded, and this vertical synchronizing signal P _V is supplied to the flip-flop circuit 52 through the terminal 51 and frequency-divided.
A signal S _f (FIG. 5B) is obtained which inverts the state for each field. This signal S _f is supplied to a flip-flop circuit 53 and frequency-divided, from which a signal S _FA whose state is inverted every frame (Fig. 5C)
A signal S _FB (FIG. 5D) having an opposite phase to this signal S _FA is obtained.

The signal S _FA is supplied to the main feed signal generation circuit 40A of the first running system 1, and the signal _SFB is supplied to the main feed signal generation circuit 40B of the second running system 2. The main sending signals S _TA (Fig. 5E) and S _TB are generated from the generating circuits 40A and 40B.
(FIG. 5F) is obtained.

In this case, as is clear from the figure, the main feed signals S _TA and S _TB rise from the rising edge of the signals S _FA and S _FB, respectively, and from this point on, the period slightly shorter than 1/2 field is correct. The DC voltage becomes a negative DC voltage in the subsequent section slightly shorter than 1/2 field.

Therefore, in every other one frame section F _A , the main feed signal S _TA is obtained and is supplied to the motor 13M via the drive circuit 41A, and in the remaining every other one frame section F _B , A main feed signal S _TB is obtained and supplied to the motor 23M via the drive circuit 41B.

In each motor 13M and 23M, rotation torque in the forward rotation direction is generated in the positive voltage section of the signals S _TA and S _TB , rotation torque in the reverse direction is generated in the negative voltage section, and rotation in the forward direction is generated. The brakes are applied against. And these motors 13M and 23
The rotation of M is detected by tachometers 42A and 42B, respectively, and the detection outputs are sent to amplifiers 43A and 43.
B respectively, the stop detection circuit 44
A and 44B, and this stop detection circuit 44
A and 44B detect that the rotation of motors 13M and 23M has stopped, and a detection pulse is obtained, which is sent to main feed signal generation circuits 40A and 40B.
The main feed signals S _TA and S _TB are set to 0 volts, and the motors 13M and 23M are stopped.

Note that FIGS. 5F and 5I show changes in the acceleration of the tapes 3 and 4, respectively, and the main feeding period is, for example, 12 to 13 msec.

As described above, the motors 13M and 23M are alternately rotated every frame section, so that the capstans 13 and 23 alternately move the tapes 3 and 4 by a certain amount 2P every frame section.
It will be sent one by one.

At each tape transfer time, the signal S
The detection circuits 45A and 45B detect the point in time when _TA and _STB switch from a positive voltage to a negative voltage, and from this the detection pulses _CTA (FIG. 5G) and _CTB are detected.
(FIG. 5J) is obtained, which is supplied as a control signal to the heads 38A and 38B and recorded on, for example, the side edges of the tapes 3 and 4, respectively.

Then, in each one frame period when the tape is stopped, one frame of video signal is
Each field is recorded on each track.

In this case, the switching signal for each head is formed, for example, from the signals S _f , S _FA and S _FB .

In this case, it is determined by the vertical synchronization signal P _V and a signal indicating the rotational phase of each rotary head obtained at a point τ before the point when each rotary head just starts scanning from the side edge of the tape. , a so-called rotational phase servo is applied, and the signal S _FA and the signal S
The rotational phase of the rotary heads is controlled so that each head starts scanning from the side edge of the tape immediately after the rise of _FB , and a vertical synchronization signal is recorded at the end of each recording track. be done.

Next, the time of reproduction will be explained.

During this reproduction, the vertical period reference signal P
_F is connected to the flip-flop circuit 52 through the terminal 51.
Similarly to recording, the flip-flop circuit 52 outputs a signal S _f (FIG. 6A) that inverts the state every field, and the flip-flop circuit 53 outputs a signal S f that inverts the state every frame. _FA (FIG. 6B) and its inverted signal _SFB are obtained.

Then, as in the case of recording, the motors 13M and 23M are driven from the time when the signals S _FA and S _FB rise to start transporting the tapes 3 and 4.
Then, within each one frame period, the tape stop position is controlled by controlling the tape feeding amount as described later, and at each stop position, the first running system 1 and the second running system 2 In this way, video signals for one frame are alternately reproduced every frame period.

At that time, the switching signal for the reproduced video signal from each head is formed from the signals S _f , S _FA and S _FB as in the case of recording.

Next, control of the tape stop position and therefore the tape transport amount will be explained.

That is, during one frame period in which the signal _{S_TA} is "1", the switch circuits 35, 36 and 37 are switched to the input terminal A side by this signal _{S_FA} , for example.

Then, when this signal S _FA rises, the main feed signal S _TA (FIG. 6C) is obtained from the main feed signal generation circuit 40A as in the case of recording, and this is sent to the drive through the adder circuit 49A and the contact P side of the switch 31. Supplied to circuit 41A, motor 13M
is driven, and the tape 3 is main fed. and,
When the stop detection circuit 44A detects that the speed of the tape 3 has become zero, the detection pulse
The main feed signal _STA is set to 0 volts by R ₁ (K in FIG. 6), and the tape 3 is stopped.

During this main feed, the control signal C _TA (FIG. 6H) is reproduced by the head 38A, and this is transmitted through the amplifier 58A and the OR circuit 59 to the first correction width generation circuit 60 and the second correction width generation circuit. 6
1.

On the other hand, the signal S from the flip-flop circuit 53
_FA is supplied to the monostable multivibrator 55 via the OR circuit 54, and from this a pulse S _D (FIG. 6E) is obtained, which falls at a time slightly delayed from the rise of the signal S _FA . The monostable multivibrator 56 is activated by the falling edge of S _D.
is triggered, resulting in a pulse S _G1 (FIG. 6F) that falls at the time when the main feed signal S _TA switches from a positive DC voltage to a negative DC voltage. Furthermore, the monostable multivibrator 57 is triggered by the falling edge of this pulse S _G1 , and from this, a pulse S _G2 with approximately the same pulse width as the pulse S _G1 is generated.
(Figure 6G) is obtained.

Then, the pulse S _G1 is generated by the first correction width generation circuit 6.
0, the pulse S _G2 is generated by the second correction width generation circuit 61
are supplied respectively.

The playback point of the playback control signal _CTA is the 6th
Just when the main feed signal _STA is switched from a positive DC voltage to a negative DC voltage, as indicated by _t0 in Figure H, the first and second correction width generation circuits 60 and 61 output I can't get a pulse.

The playback point of the playback control signal _CTA is the 6th
When the time is before time _t0 as shown by _t- in _{FIG .}
A signal W ₁₁ (FIG. 6) which becomes "1" from t _- to time t ₀ is formed. When this signal W ₁₁ is obtained, this signal W ₁₁ is supplied to the hold circuit 62 and held for a certain period of time, and its hold output prevents the monostable multivibrator 57 from obtaining the pulse S _G2 . be done.

The playback point of the playback control signal _CTA is the 6th
If the time is later than time _t0 , as _shown by t ₊ in _FIG.
A signal W ₁₂ (FIG. 6') is formed which is "1" from t ₀ to time t ₊ .

Here, 68 is a circuit that forms a signal indicating to which side the reproduction timing of the control signal _CTA is shifted with respect to time _t0 , and for example, a monostable multivibrator is used. That is, when the reproduction timing of the reproduction control signal is shifted to the t ₊ side, the output signal W ₁₂ is obtained from the second correction width generation circuit 61, but the monostable multivibrator 68 is activated by the leading edge of this signal W ₁₂ . When triggered, the output signal UD ₁ is a pulse that is "1" for a period longer than the pulse width section of the pulse S _G2 as shown in FIG. 6 J', and the reproduction control signal C _TA
When the reproduction timing of the signal W 11 is shifted to the t _- side and the signal W ₁₁ is obtained from the first correction width generation circuit 60, the signal W ₁₂ does not rise, so the output signal UD ₁ of the monostable multivibrator 68 is As shown in Figure 6J, it remains "0".

The pulse signal W ₁₁ or W ₁₂ thus obtained is supplied to one input terminal of the AND circuit 65 through the OR circuit 63, and the signal W ₁₁ or W ₁₂ is supplied to one input terminal of the AND circuit 65.
The clock generator 6
A clock pulse of a certain period from 4 is gated, and the output of this AND circuit 65 receives a pulse signal.
A number of clock pulses C _P1 are obtained depending on the pulse width of W ₁₁ or W ₁₂ . This clock pulse C _P1 is then supplied to an up-down counter 67 through an adder circuit 66.

On the other hand, the output signal _UD1 of the monostable multivibrator 68 is supplied to the up-down counter 67 through the OR circuit 69 as up-down information indicating whether to up-count or down-count the clock pulse C _P1 .

That is, when the pulse signal W ₁₁ is obtained from the first correction width generation circuit 60, the output signal UD ₁ becomes "0", which indicates down count information, and a number of pulses corresponding to the pulse width of the signal W ₁₁ are output. The clock pulse C _P1 is counted down by a counter 67. Further, when the pulse signal W ₁₂ is obtained from the second correction width generation circuit 61, the output signal UD ₁ becomes "1", which indicates up count information, and the number of pulses corresponding to the pulse width of the signal W ₁₂ is increased. The clock pulse C _P1 is counted up by a counter 67.

Then, the count value information of the counter 67 is supplied to the latch circuit 46A through the switch circuit 35, and the count value of the counter 67 is determined whether it is an up-count value or a down-count value with respect to the value at the time of clearing. Up-down information is passed through the switch circuit 36 to the latch circuit 46.
A is supplied. In this case, the most significant bit of the counter 67 is used as the up-down information, for example.

The latch circuit 46A is supplied with a stop detection pulse R ₁ (K in FIG. 6), which is obtained when the tape once stops after being sent by the main feed signal from the stop detection circuit 44A, as a latch pulse. , at the time of this pulse R ₁ , the counter 6
Count information and up-down information from 7 onwards are stored and held. And at the same time,
Pulse R ₁ is supplied to the clear terminal of counter 67 through OR circuits 82A and 83, and counter 67 is cleared.

The information stored in latch circuit 46A is supplied to control circuit 47A. Further, signals for commanding operations such as recording, playback, fast forwarding, and rewinding, and signals for commanding forward and reverse rotational directions of the motor are supplied from the system control device to this control circuit 47A. In this control circuit 47A, when the stored up-down information is up-count information, it is rotation direction information that gives rotation in the same direction as the rotation direction of the main feed, and when it is down-count information, it is used as main feed rotation direction information. Rotation direction information that gives rotation in the opposite direction to the feed rotation direction is formed, and the count information stored in the latch circuit 46A is converted into an analog signal, and the count information is converted into an analog signal according to the count value of the counter 67. DC voltage E _C is obtained.

Then, the rotation direction information from this control circuit 47A and the DC voltage E _C according to the count value.
is supplied to the correction sending signal forming circuit 48A.
In this correction feed signal forming circuit 48A, a pulse voltage with a pulse width corresponding to the value of the DC voltage E _C is formed, but the voltage value in this pulse width section is a constant positive voltage or a constant negative voltage depending on the rotation direction information. It is considered to be voltage.

In other words, the example in the figure is for normal playback, and
Since the rotation direction of the motor is the forward rotation direction, when the up-down information from the latch circuit 46A is down count information, a constant negative pulse voltage is obtained from the correction feed signal forming circuit 48A, and the up-down When the information is up count information, a constant positive pulse voltage is obtained from the correction sending signal forming circuit 48A.

This pulse voltage is then supplied to the drive circuit 41A through the adder circuit 49A, and the motor 1
3M is rotated in the forward direction when the voltage is positive, and in the reverse direction when the voltage is negative.

Therefore, if the timing of the playback of the control signal _CTA is shifted to the t _- side and the tape 3 is stopped too far from the intended stop position, the first correction width is adjusted as described above. The signal _W11 is obtained from the generation circuit 60, and the clock pulse C _P1 is counted down by the counter 67 during the pulse width section of this signal _W11 . At the time when the detection pulse R ₁ is obtained, a negative pulse voltage with a pulse width corresponding to the pulse width of the signal W ₁₁ is obtained as a correction feed signal in the correction feed signal forming circuit 48A, thereby causing the motor 13M to rotate in the reverse direction. The tape 3 is returned by an amount corresponding to the pulse width of the signal _W11 .

If the playback timing of the control signal _CTA is shifted to the t ₊ side and the tape 3 stops before the intended stop position, the second correction width generation circuit 61 generates a signal as described above. W ₁₂ is obtained, and the clock pulse C _P1 is incremented by the counter 67 during the pulse width section of this signal W _12. Therefore, at the time when the detection pulse R ₁ is obtained from the stop detection circuit 44A, the correction feed signal forming circuit At the output of 48A, a positive pulse voltage with a pulse width corresponding to the pulse width of the signal _W12 is obtained as a corrected sending signal,
As a result, the motor 13M is rotated in the forward direction, and the tape 3 is further advanced by an amount corresponding to the pulse width of the signal _W12 .

Thus, the _first
In this case, the corrective feed is performed, but in this case,
Since the playback point of the control signal _CTA is at the end of the first half of the main feed, this first correction feed only corrects the amount of deviation in the first half of the main feed.
If a feed deviation occurs in the latter half of the main feed,
This is not corrected and therefore there is no guarantee that the tape stop position after the first corrective feed is the correct stop position.

Therefore, in the present invention, the following correction feed is further performed.

If the playback output from each head is switched at the point when the head just begins scanning from the side edge of the tape, each head will start scanning from one end of the recording track and scan from the other end. A reproduced signal is obtained during the period of scanning up to the end.

Then, in this state, when the reproduction signal from each head is switched, and when the head just scans each track correctly, a reference horizontal synchronization pulse is applied that is equal to the phase of the horizontal synchronization signal. The phase of this pulse is compared with the phase of the actual reproduced horizontal synchronization signal.

If the head is in the just tracking state, there will naturally be no phase difference, but for example, the playback signal of a certain head may show a position shifted relative to the track T, as shown by the dotted line in Figure 7. If the tape is scanned, the phase of the reproduced horizontal synchronizing signal will be more advanced than the standard horizontal period signal, and if the scanning position of the head is taken as a reference in the longitudinal direction of the tape. On the other hand, if there is a shift as shown by the dashed line in FIG. 7, the phase of the reproduced horizontal synchronization signal lags behind the signal of the reference horizontal period.

The amount of phase shift is proportional to the scanning position shift of the head with respect to the longitudinal direction of the tape.

Therefore, by correcting and feeding the tape in accordance with the amount of phase shift, the tape can be stopped at a position where each head is in a straight tracking state.

In order to achieve the above, in this example, the following is done.

That is, 39A is a pulse generator from which a signal indicating the rotational phase of the rotary heads 18 and 19 can be obtained;
From this, a pulse signal _PGA (Fig. 6M) is obtained at a point τ before the heads 18 and 19 start scanning from the side edge of the tape 3, and this pulse signal _PGA causes a monostable vibrator 7
0A is triggered, and from this, a pulse M _A (N, N', N'' in FIG. 6) whose trailing edge is at a time point τ after the time point of the pulse signal PG _A is obtained, and this pulse is sent through the switch circuit 37 to the No. 3 correction width generation circuit 72
is supplied to

On the other hand, the output S _f of the flip-flop circuit 52 is supplied to the Schmitt circuit 71, which generates a pulse P _f (L in Fig. 6) at the falling edge of the output S _f .
is obtained and supplied to the third correction width generation circuit 72.

The correction width generating circuit 72 generates a pulse having a width corresponding to the phase difference between the falling edge of the pulse M _A and the pulse P _f .

Here, the time of the trailing edge of pulse M _A is the time when each head 18 and 19 is just about to start scanning from the side edge of the tape, and also the time when the reproduction signal from each head is switched. Since the signal is formed from the signals S _f and S _F , the pulse P _f
is nothing but a signal indicating the switching point of the reproduction signal. Therefore, if there is no phase difference between the two, the time point at which the reproduction signal is switched can be set at the time point at which the head starts scanning on each track.

That is, when the pulse signal P _A is obtained τ before the pulse P _f as shown by P ₀ in FIG. 6M, the falling point of the pulse M _A is as shown in FIG. 6N. This coincides with the pulse P _f and there is no phase difference between the two, so no pulse can be obtained from the correction width generation circuit 72. At this time, the time point at which the reproduction signal is switched is the point at which the head starts scanning each track.

When the pulse signal PG _A is obtained before the time point P ₀ as shown by P _- in FIG. 6 M, the pulse M _A becomes as shown in FIG. 6 N', and the correction width generating circuit 7
2, a pulse signal W ₂₁ (FIG. 6O) is obtained which is "1" from the trailing edge of the pulse M _A to the time of the pulse P _f .

As shown by P ₊ in Fig. 6, the pulse signal PG _A is
When obtained later than the time point P ₀ , the pulse M _A
is as shown in FIG. 6N″, and the correction width generation circuit 72
Therefore, the pulse signal W ₂₂ becomes "1" from the time of pulse P _f to the trailing edge of pulse M _A (Fig. 6 O').
is obtained.

The pulse signal W ₂₁ or W ₂₂ obtained by the correction width generation circuit 72 is supplied to one input terminal of an AND circuit 74 through an OR circuit 73, and is used to generate a clock oscillator in the pulse width section of the pulse signal W ₂₁ or W ₂₂ . The clock pulse C _P2 from 75 (however, this clock pulse C _P2 has the same repeating period as the clock pulse C _P1 ) is gated. Therefore, at this time, this AND circuit 74 has
A number of clock pulses C _P2 corresponding to the pulse width of the signal W ₂₁ or W ₂₂ are obtained and supplied to the counter 67 through the adding circuit 66.

On the other hand, the monostable multivibrator 76 is triggered by the pulse P _f from the Schmitt circuit 71, and the output signal UD ₂ (P in FIG. 6) which is "1" for at least the period τ from the time of the pulse P _f is generated. This is given to the counter 67 through the OR circuit 69 as its up count information or down count information.

In other words, the time point at which the pulse signal PG _A is obtained is P ₀
When the signal W ₂₁ is obtained from the correction width generation circuit 72 on the P _- side, the signal UD ₂ is in the "0" state, and the number of clock pulses C _P2 corresponding to the pulse width of the signal W ₂₁ is will be counted down. Also,
When the signal W ₂₂ is obtained from the correction width generation circuit 72 on the P ₊ side where the time point at which the pulse PG _A is obtained is delayed from P ₀ , the signal UD ₂ is in the “1” state, so the signal W ₂₂ is The number of clock pulses C according to the pulse width
_P2 is counted up.

Therefore, based on the count value of the counter 67 and the up-down information at this time, the correction feed signal forming circuit 48A forms a correction feed signal, and the motor 13M is driven by this signal to correct the tape 3. The switching timing of each head 18 and 19 should be such that the head is about to begin scanning from the side edge of the tape.

Next, the output signal S of the flip-flop circuit 52
_f is supplied to the reference horizontal period signal generation circuit 77, which generates a horizontal period pulse RH synchronized with the signal S _f .
(Fig. 6 Q) is obtained. Since the switching signal for the reproduction signal from the head is formed from this signal S _f and the signal S _F , this horizontal period pulse RH
is in phase with the reproduced horizontal synchronizing signal when the head is in the just tracking state.
Then, this signal RH is supplied to the fourth correction width generation circuit 7.
8.

On the other hand, when approximately one field has elapsed from the start of the main feed, the tape 3 has almost stopped and the rotary head is in a state of scanning over the recording track even though it is not in a straight tracking state. The reproduced video signal can be obtained from the head. Therefore, a reproduced horizontal synchronizing signal PBH (FIG. 6R) is separated from this reproduced video signal and supplied to the correction width generating circuit 78.

Furthermore, the output signal S of the flip-flop circuit 52
_f and the pulse RH from the reference horizontal period signal generation circuit 77 are supplied to the gate pulse generation circuit 79, and after one field has elapsed from the start of main feed, 1/2 horizontal period before and after the pulse RH is A gate pulse S _G3 (S in FIG. 6) which becomes "1" in one predetermined horizontal section is obtained and is supplied to the correction width generating circuit 78.

Then, the correction width generation circuit 78 generates a signal W 3 having a pulse width equal to the phase difference between the pulse RH and the reproduced horizontal synchronizing signal PBH in the section where the gate pulse S _G3 is "1 _" (T in FIG. 6). is obtained. This is then supplied to one input terminal of the AND circuit 74 through the OR circuit 73, and the signal W ₃
A clock pulse C _P2 from the clock generator 75 is gated with a pulse width period of , and is supplied to the counter 67 via the adder circuit 66.

On the other hand, the pulse RH from the reference horizontal period signal generation circuit 77 is supplied to the waveform shaping circuit 80, which generates a rectangular wave signal S _H of the duty factor 50%.
(U in FIG. 6) is obtained and supplied to the gate circuit 81. On the other hand, this gate circuit 81 is turned on during the period when the gate signal S _G3 is "1".
Therefore, from this gate circuit 81, the second half of one horizontal period when the gate signal S _G3 is "1"
Signal UD ₃ that is “1” only in the horizontal period (Figure 6 V)
is obtained, and this is given to the counter 67 through the OR circuit 69 as its up-count information or down-count information.

Here, assuming that the tape transport direction is the direction shown by the arrow in FIG. As shown in FIG. 6R, it is obtained after the pulse RH, and at this time, since the output signal UD ₃ of the gate circuit 81 is "1", the pulse width of the signal W ₃ from the correction width generation circuit 78 is The corresponding number of clock pulses C _P2 is counted up by a counter 67.

Also, if the scanning position of the head is shifted from the track T in the opposite direction to the tape transport direction,
The reproduced horizontal synchronization signal PBH is obtained before the pulse RH, and at this time, the output signal of the gate circuit 81
Since _UD3 is "0", the counter 67 counts down the number of clock pulses C _P2 corresponding to the pulse width of the signal _W3 from the correction width generating circuit 78.

At this time, the counter 67 first receives the signal W ₂₁
Or, since the number of clock pulses _CP2 corresponding to the pulse width of signal _W22 is counted up or down, the count value of clock pulses _CP2 of the number corresponding to the pulse width of signal _W3 is further added or subtracted. That will happen.

Then, when the total count value is an up-count, the counter 67 outputs the count information at that time,
When up-count information is obtained as up-down information and the total count value is a down-counted value, the counter 67 outputs the current count information and
Down count information is obtained as up down information.

The count information and up-down information from the counter 67 are supplied to the latch circuit 46A through switch circuits 35 and 36, respectively. Then, the detection output pulse R ₁ of the stop detection circuit 44A is supplied to the delay circuit 50A, and from this, the pulse R ₂ is generated at a point after the trailing edge of the gate signal S _G3 from the gate circuit 79 (W in FIG. 6). is obtained, and the count information and up-down information from the counter 67 at that time are latched and stored in the latch circuit 46A by this pulse _R2 . Further, this pulse R ₂ is supplied to the clear terminal of the counter 67 through OR circuits 82A and 83,
This will be cleared.

Then, in the same manner as described above, this latch circuit 46
According to the information from A, the correction sending signal forming circuit 4
A positive or negative pulse voltage is obtained from 8A as a correction feed signal, which drives the motor 13M to further return or advance the tape 3.

At this time, the information stored in the latch circuit 46A is such that the rotation phase of the rotary head is adjusted so that the phase difference between the pulse of the reference horizontal period and the reproduced horizontal synchronization signal disappears in the state of just tracking. This information is the sum of the information to set the phase and the information corresponding to the difference between the phase of the reproduced horizontal synchronizing signal and the phase of the pulse of the reference horizontal period, and the tape 3 is forwarded or reversed depending on this information. Since there is no difference between the phase of the reproduced horizontal synchronizing signal and the phase of the reference horizontal period pulse, after this correction feed is completed, the head is at the position where it is in the just tracking state. The tape is stopped at this point.

In the second running system 2, main tape feeding and correction tape feeding are performed in exactly the same manner. Therefore, the parts of the second running system 2 that correspond to those of the first running system 1 are given the same numbers with the suffix B, and the explanation thereof will be omitted.

As described above, according to the present invention, by performing the first correction feed based on the control signal and the second correction feed based on the playback horizontal synchronization signal, the stop position of the tape can be approximately adjusted. The head can be placed in the correct position for just tracking.

By the way, in a normal VTR, when performing correction based on the playback horizontal synchronization signal, the playback horizontal synchronization signal is obtained from the playback video signal in which the playback image is actually displayed, and the correction signal is formed based on this playback horizontal synchronization signal. The correction was completed in about 10 seconds.
There is a frame delay and a non-negligible skew appears in the reproduced image.

In contrast, in the present invention, the reproduced horizontal synchronization signal used to form the correction signal is not obtained from the reproduced video signal from the running system that is in the reproduction state during that one frame period, but rather Since it is obtained from the video signal to be reproduced in the next one frame period from the running system in which the tape is transported in the period, the delay in correction is reduced, and the reproduced video signal obtained in the next one frame period is This has the effect that almost no skew appears in the reproduced images.

In addition, in the example shown in the figure, there are two running systems, so if the tracking position in each is shifted in the opposite direction to the tape transport direction, the time when the playback video signal from each head is switched, that is, the video Although there is a drawback that jumping of the horizontal synchronization signal occurs at signal joints, as described above, this drawback can be eliminated by corrective feeding based on the reproduced horizontal synchronization signal.

Furthermore, in the above example, the correction feed signal is formed digitally, and furthermore,
Since only one counter is required for a plurality of correction width signals, the configuration is simple.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an example of a recording/reproducing apparatus to which the present invention is applied, FIGS. 2 and 3 are diagrams showing a time chart and a track pattern for explaining its operation, and FIG. Fig. 5 is a time chart for explaining tape feeding during recording, and Fig. 6 is a time chart for explaining tape feeding during playback. , FIG. 7 is a diagram for explaining the operation. 3 and 4 are tapes, 13 and 23 are capstans, 13M and 23M are capstan driving motors, 12 and 22 are rotary head devices, 18, 19
and 28, 29 are rotating magnetic heads, 38A and 3
8B is the control signal head, 39A and 3
9B is a pulse generator for obtaining a pulse signal indicating the rotational phase of the rotary head; 48A and 48B are correction feed signal generation circuits; 60, 61, 72 and 78 are correction width generation circuits; and 77 is a reference horizontal frequency signal generation circuit. .

Claims (1)

[Scope of Claims] 1. An apparatus for intermittently transporting a magnetic tape medium and recording and reproducing signals while the tape medium is stationary; The intermittent transfer of one pitch of the track is performed by (a) main feeding using a main feeding signal that applies driving force in the positive and negative directions to the tape medium drive motor based on a signal with a vertical period; b) Detecting the relative time difference between the time point at which the positive/negative direction signal of the main feed signal switches and the time point at which the control signal for tape position display recorded on the tape medium is reproduced during the main feed. (c) Based on the time difference, a correction feed signal is formed to apply a driving force in a positive direction or a negative direction to the motor, and this correction feed signal is applied when the drive of the tape medium by the main feed signal is stopped. A method for intermittent tape transport of a recording/reproducing device, comprising the steps of supplying the tape to the motor from the point in time. 2. A device that transports a magnetic tape medium intermittently and records and reproduces signals while the tape medium is stationary, and when reproducing signals, one pitch of the track recorded on the tape medium is recorded. The intermittent transfer is performed by (a) main feeding using a main feeding signal that applies driving force in the positive and negative directions to the tape medium drive motor based on a vertical periodic signal, and (b) using the main feeding signal as described above. (c) detecting a relative time difference between the time point at which the positive and negative direction signals of the tape switch switch and the time point at which a control signal for indicating the tape position recorded on the tape medium is reproduced during the main feed; A first corrected feed signal is formed based on the time difference to provide a driving force in a positive direction or a negative direction to the motor, and this first corrected feed signal is
(d) supplying the video signal to the motor from the time when the tape medium drive by the main feed signal stops; (d) after supplying the first correction feed signal to the motor, the video signal is being supplied while the tape medium is stopped; (e) regenerating a horizontal synchronization signal from the motor and detecting a relative shift difference between the regenerated horizontal synchronization signal and a signal with a reference horizontal period; A method for intermittent transport of a tape in a recording/reproducing apparatus, comprising the steps of: forming a second correction feed signal that provides a driving force in the direction; and supplying the second correction feed signal after the tape is transferred by the first correction feed signal. .