JPS633387B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a slow motion playback device, and in a magnetic playback device that performs slow motion playback by intermittently feeding a tape-shaped recording medium, the voltage applied to the capstan motor is set at a relatively high level at startup. It is an object of the present invention to provide a slow motion reproducing device which can perform extremely good and stable slow motion reproduction by lowering the value to a relatively low value immediately before stopping.

The present applicant previously proposed a magnetic reproducing device capable of performing suitable slow motion reproduction in Japanese Patent Application No. 10416/1983. The proposed magnetic reproducing apparatus is an apparatus for reproducing a previously recorded signal from an inclined track on a tape-shaped recording medium using, for example, two rotary heads having gaps with different azimuth angles and different track widths. A still image at a predetermined position where a noise bar does not appear on the playback screen due to a drop in the playback FM level that occurs when the rotary head crosses a track recorded by a rotary head with a gap of an azimuth angle different from that of itself (so-called reverse track). After reproduction is performed for an integral number of frame times, the tape-shaped recording medium is advanced by one frame at approximately 2 to 3 times the frame time in synchronization with the rotation of the rotary head, and a control pulse is detected to ensure that the noise bar does not appear again. The system repeats the operation of stopping at a certain position and playing still images for an integer multiple of the frame time, and then changing the repetition time ratio to obtain a playback signal with an arbitrary slow motion ratio. The tape-shaped recording medium is made to run intermittently by intermittently driving a stun motor.

According to the above-mentioned magnetic reproducing apparatus proposed by the present applicant, the essence of the azimuth recording/reproducing method can be skillfully achieved with an inexpensive configuration without the need for a complicated head moving mechanism for displacing the rotating head in the track width direction. It has an excellent feature that it can be used to perform slow-motion playback or still-motion playback without noise bars appearing, and is particularly suitable for application to home VCRs.

However, in the above-mentioned magnetic reproducing device proposed by the present applicant, it is necessary to alternately drive and stop the capstan motor during slow motion reproducing, but the inertia of the capstan system allows for a rapid rise from stop to start. It was difficult to do so, and it was also difficult to stop the rotating capstan motor at a predetermined timing position, so on the actual screen, the screen shakes,
Alternatively, there was a problem that noise was generated, leading to a decrease in slow motion playback image quality.

That is, in order to drive the capstan motor for a certain period of time and then stop it, the device proposed by the applicant applies a rectangular drive voltage to the capstan motor. In the case of a rectangular wave shown by a dashed dotted line _a in Figure 1A,
As a result, the running distance versus time of the tape-shaped recording medium that is made to run is as shown by the dashed line _b in FIG _. As shown in
For example, regarding speed, the state in which a rectangular wave is integrated, that is, the response characteristics are extremely poor, resulting in the above-mentioned problem.

As a method to solve such problems, for example, an adjusting means is used in which the time from when a regeneration control pulse is detected to when the rotation of the capstan motor is stopped is varied and the rotation is stopped at a predetermined timing position. It was difficult to remove screen shakes, etc.

In order to eliminate the above-mentioned disadvantages, the present invention forms a waveform in which the drive voltage applied to the capstan motor is at a relatively high level at startup and at a relatively low level immediately before rotation is stopped. Examples of such a waveform include a staircase wave as shown by the broken line _a in FIG. 1A, or a triangular wave (not shown) that gradually decreases over time. However, although both of these waveforms can give good results, the staircase wave lacks stability when its voltage changes, while the triangular wave does not have the instability of the staircase wave, but all are slope waves. , so the best results cannot be obtained.

Therefore, in this embodiment, as will be described later, a capacitor discharge waveform that approximately combines the advantages of each of the above-mentioned waveforms is used, and thereby the best results can be obtained.

First, before explaining the slow motion reproducing operation, the general reproducing operation of the magnetic recording and reproducing apparatus to which this embodiment is applied will be explained. In FIG. 2, during playback, switches 26, 28, and 36 are connected to contact P, and switch 41 and switch circuit 43 are connected to contact P.
is connected to contact N. control head 27
The control signal c shown in FIG. ₁ to a monostable multivibrator (hereinafter referred to as MM) 45. As a result, MM45
The output signal d shown in FIG.
9 as a sampling signal.

On the other hand, each time the magnets 33a and 33b, which are mounted opposite to each other on a disk 32 that rotates integrally with the rotating shaft of the drum motor 15, pass a position where they are opposed to and separated from the gap surface of the detection head 34.
The detection head 34 outputs a pulse and applies it to a flip-flop (hereinafter referred to as FF) 35 to invert the output. As a result, the third version from FF35
A rectangular wave b as shown in FIG. The trapezoidal wave forming circuit 37 generates a trapezoidal wave as shown in FIG. 3E (this has the opposite polarity to the trapezoidal wave during recording) e
is taken out and supplied to the sampling and holding circuit 29, where it is sampled and held by the sampling signal d. The output signal of this sampling hold circuit 29 is applied as a driving voltage to the drum motor 15 via a motor drive amplifier 30, and a reproduction control signal c
matches the reference phase, and the video head 13
The rotation of the drum motor 15 and the rotary drum 16 is controlled so that the drum motor 15 and the rotary drum 16 are accurately scanned over the recorded track. Note that the rotating shaft 31 of the drum motor 15 passes through the fixed lower drum and connects to the rotating drum 1.
It is connected and fixed at the center of 6. Recorded video signals on the magnetic tape 18 reproduced by the video heads 13a and 13b provided on the rotating drum 16 are taken out from the terminal 54 via the recording/reproducing circuit 12.

Note that if a trapezoidal wave having the same waveform as that during recording is used as a sampled signal during reproduction, there will be a limit to the operation of advancing the rotational phase. For this reason, during reproduction, the downward slope to the right of the phase-inverted trapezoidal wave e is sampled at the rising edge of the signal d delayed by time _t1 .

Note that the gaps of the video heads 13a and 13b have opposite azimuths, so when the video heads 13b and 13a respectively scan the tracks recorded by the video heads 13a and 13b (so-called reverse tracking), the signals are distorted due to azimuth loss. Not played. However, during normal playback, the third
2 from the control head 27 as shown in Figure C.
The rotational phases of the drum motor 15 and the rotary drum 16 are controlled so that the sampling signal d formed by the MM 45 samples the central portion of the slope of the trapezoidal wave e by the positive polarity pulse for each field. Here, the positive pulse from the control head 27 is set to occur, for example, in accordance with the rotational position of the head 13a. Therefore, video heads 13a and 13b are always connected to head 13, respectively.
The rotational phase is controlled so as to scan (forward tracking) the track recorded by a and 13b,
As mentioned above, reverse tracking does not occur.

As shown in FIG. 4, the video heads 13a and 13b have gaps 60a and 60b that are tilted at an angle α in opposite directions to the direction perpendicular to the scanning direction, that is, have an azimuth of α. Head 13a, 1
3b have different track widths W ₁ and W ₂ , respectively, and are provided such that their respective end faces 61 a and 61 b are on the same reference plane of the rotating drum 16 .

In this embodiment, W ₁ is approximately 1.5W ₂ to 1.6W ₂ .

Forming a video signal recording track on the tape 18 by the heads 13a and 13b is performed as follows. Head 13 rotating in the direction of arrow Y in Fig. 4
When a scans the tape, a recording track with a width _W1 is formed obliquely to the longitudinal direction of the tape. Next, when the head 13b scans the tape by overlapping the track formed by the head 13a with a width W ₀ , the width W ₂ (=
A recording track of T) is formed. Here is the superimposition width
W ₀ is set so that W ₀ =W ₁ -T.

However, since the recorded video signal is frequency modulated, as is well known, when the head scans and records a new signal by superimposing it on an already recorded track part, the bias effect of the new signal causes the previously recorded signal to be distorted. is erased and a new signal is recorded. Therefore, the signal recorded by head 13a remains as track _t1 of width T, and the signal recorded by head 13b remains as track _t2 of width T. Thereafter, in the same manner, a track t ₃ of width T,
t ₅ , t ₇ . . . (the subscript of t is a parsimonious number) are formed, and tracks of width T are recorded by the head 13b as t ₄ , t ₆ ,
t ₈ ... (the subscript of t is an even number) is formed.

In order to closely form the tracks in this way, it is not necessary that the tracks of each head have different widths as described above, but the heads may have the same track width. However, in this apparatus, the track widths of the playback heads must be different for slow motion playback, which will be described later, and the playback head can also perform recording, so the above explanation is given.

Here, the tracks t ₁ , t ₂ , t _{3 .} . . are in close contact with each other without any gaps, increasing the tape utilization rate. Each track records substantially one field of the video signal. Here, the video heads 13a, 13b and the magnets 33a, 3 are connected so that the vertical synchronizing signal of the video signal is located near the end of the track.
3b and the time constant of the phase adjusting MM25 are adjusted. Note that at the lower edge of the tape 18, the control signal is
The data is recorded on the control track 62 shown in FIGS.

Next, the operation for static playback will be explained with reference to FIG. For still image playback, magnetic tape 1
8 is stopped, and the video heads 13a, 13
b is rotated at the same rotational speed during recording and normal playback.

In FIG. 5, for example, when the head 13b starts scanning from a position spanning tracks t ₆ and t ₇ ,
Scanning is performed along the trajectory shown by the bold line, and the scanning ends at a position spanning tracks _t5 and _t6 . Since the tape 18 is stopped, the end surface 61 of the head 13a is also aligned with the head 1.
In order to follow the same locus as the end surface 61b of 3b, scanning starts from a position spanning tracks _t6 to _t8 , and ends at a position spanning tracks _t5 to _t7 . Thereafter, the above scanning is repeated.

Heads 13b and 13a are in a normal tracking relationship with respect to tracks _t6 and _t7 , respectively. Therefore, the levels of the signals reproduced by the heads 13b and 13a are as shown in FIG. Here, head 1
Assume that the relative scanning positions of the tapes 3a and 13b with respect to the tape 18 are shifted, for example, to the left from the illustrated state. In this case, the reproduction level L ₁ at the start of scanning for track t ₆ of the head 13b increases, or the reproduction level L ₂ at the end of scanning decreases. Furthermore, the reproduction period of the head 13a at the maximum level _L3 for track _t7 becomes shorter, and the ratio of scanning track _t5 at the end of scanning for track _t7 increases, resulting in beat disturbance in the vicinity of level _L4 . On the other hand,
If the relative tape scanning positions of the heads 13a and 13b shift to the right from the state shown in the figure, the reproduction level _L1 decreases from the track _t6 of the head 13b, and the SN ratio in this reproduction portion deteriorates significantly. Therefore, the scanning trajectory of the heads 13a and 13b relative to the track during still image reproduction is most preferably in the state shown in FIG.

Here, when the control signal is recorded by the head 27, the video head 13b starts recording the track.
Recording of t ₂ , t ₄ , t ₆ ... is started. Therefore, if the magnetic tape 18 recorded in this manner is run and played back, and the tape run is arbitrarily stopped at the desired still image playback point, the relative stop position of the tape 18 with respect to the video head is indefinite. . For this reason, after the tape has stopped running, the tape may be moved slightly to achieve the optimum scanning state shown in Figure 5, or the tape may be run at a low speed while watching the playback screen. It is necessary to perform operations such as stopping the vehicle, which is troublesome and requires skill.

Therefore, if the running of the tape is stopped immediately upon reproducing _the control signal _c , as shown in _FIG . Become. In this case, when the scanning of the head 13b starts, the reproduction level of the track _t6 is the maximum, but when the scanning ends, the reproduction level becomes almost zero and the noise becomes _extremely large. Beats occur in the playback signal from ₅ , and the playback quality deteriorates significantly.

On the other hand, as is clear from FIG.
1b is the position scanned along the dashed line in FIG. So, after detecting the control signal,
The tape 18 is moved by a distance _l1 shown in FIG. 7 and then stopped, and tape running is stopped at a position where the heads 13a and 13b can scan in the optimum scanning state shown in FIG.

Therefore, the still image reproducing operation of this apparatus will be explained by returning to FIG. 2 again. In normal playback mode,
When the still image reproduction mode operation button (not shown) is pressed, the switches 28 and 41 are connected to the contact S. At the same time, a trigger pulse shown in FIG. 8A is supplied from the terminal 50 to the FF 49 to trigger it. Thereafter, the control signal shown in FIG. 8B (the third
The same as shown in FIG.
Supplied to M.47. The delay time constant of the MM 47 is adjusted by the variable resistor 48, and as shown in FIG. 8C, the MM 47 outputs a signal with a waveform that falls in response to a positive polarity control signal and rises after a time _t2 determined by the above-mentioned time constant has elapsed. . The output of FF49 is shown in Figure 8D.
As shown in FIG. 2, the waveform rises in response to the trigger pulse from the terminal 50 and falls in response to the rise in the output of the MM 47.

The switch circuit 43 is switched to contact S in response to the fall of the output of the FF 49. Therefore, the capstan motor 20 receives a signal from the capstan servo circuit 40 until the switch 41 is switched to the contact S as shown in FIG. Until switching to terminal S of FF 43, the signal from FF 49 passes through a motor drive waveform forming circuit 67, which will be described later.
Motor drive amplifier 42, switch circuit 4
3, the capstan motor 20 rotates. Accordingly, the capstan 19 also rotates, and the magnetic tape 18 held between the capstan 19 and the pinch roller 23 is caused to run in the direction of arrow X. However, when the switch circuit 43 is switched to the terminal S side, the capstan motor 20 is connected to the reverse voltage applying circuit 66 via the terminal S of the switch circuit 43, and this reverse voltage causes As shown in FIG. 2, the rotation immediately stops, and the magnetic tape 18 stops running. Note that the rotational speed of the capstan motor 20 is determined by a disc 22 attached to one end of the rotating shaft of the capstan motor 20 and having S-pole and N-pole magnets arranged alternately on the circumferential surface, and a detection head 39. The structure is such that a pulse having a repetition frequency corresponding to the above is applied to the capstan servo circuit 40.

Therefore, after operating the still image playback mode, time t ₃ (the above time
t ₂ plus the inertial rotation time of the motor 20)
Afterwards, the magnetic tape 18 completely stops running. Here, the distance l ₁ explained in connection with FIG. 7 is determined by the time t ₃ , and the time t ₃ can be adjusted according to the above-mentioned time t ₂ . Therefore, the variable resistor 4 is adjusted so that the distance from when the control signal is detected until the magnetic tape 18 completely stops running is the desired distance _l1 .
8 and the delay time t ₂ of MM47.

In fact, as an example, the distance l ₁ is approximately 0.4
mm, and the delay time t ₂ is approximately several milliseconds.

As a modification, a second control head (not shown) is provided at a distance _l2 expressed by the following equation from the control head 27, and the capstan motor is controlled by the control signal reproduced by the second control head. The rotation of 20 may be stopped.

l ₂ = l ₁ +2P・n−l ₃ where P is the track pitch on the magnetic tape 18 n is an integer l ₃ is the inertial travel distance of the magnetic tape 18 due to the inertia of the capstan rotation system As described above, according to this device, the magnetic tape 18 is stationary. By operating the playback mode at the time, optimal still image playback is performed with the least amount of noise and beats.

Next, an explanation will be given of the operation of the apparatus of the present invention for performing slow motion reproduction with the least noise and beats using this principle of optimal still image reproduction.

By operating the slow motion playback mode, the second
Switches 26, 28, and 36 in the figure are connected to contact P, switch 41 is connected to contact S, and switch 53 is closed. Further, the frequency division ratio of the frequency divider 51 is set according to the slow ratio of slow motion reproduction. For example, in the case of 1/2 slow motion reproduction, the frequency division ratio is set to 1/2.

The output signal b shown in FIG. 9A of the flip-flop 35 (same as the signal b shown in FIG.
The output signal f whose frequency is divided by 2 and has the waveform shown in FIG. 9B is
Supplied to MM52. The MM52 outputs a signal g having a waveform shown in FIG.

On the other hand, the control signal c shown in FIG. 9D (FIG. 3C) reproduced by the control head 27
The signal h (same as the signal shown in FIG. 8) is supplied to the MM 47, and is converted into a signal h having the waveform shown in FIG. 9E (same as the signal shown in FIG. 8C), and then applied to the FF 49. As a result, a rectangular wave i having a waveform shown in FIG. 9F is extracted from the FF 49, rising at the rising edge of the output signal g of the MM 52 and falling at the rising edge of the signal h from the MM 47.

The rectangular wave i is applied to a motor drive waveform forming circuit 67, which is a main part of the device of the present invention, and is converted there into a discharge waveform using the discharge characteristics of the capacitor. That is, the motor drive waveform forming circuit 6
7 has a circuit configuration as shown in FIG.
A resistor R ₁ is connected between the power supply voltage +V ₁ and +V ₂ (<+V ₁ ),
Switches S ₁ , S ₂ and resistor R ₂ are connected in series, and the connection point of switches S ₁ and S ₂ is connected to the switch.
Connected to the base of the NPN transistor Tr via _S3 . Further, a charging/discharging capacitor C whose one end is grounded is connected between the connection point between the switches S ₁ and S ₂ and the switch S ₃ . Furthermore, the base of the transistor Tr is grounded via a resistor _R3 , the emitter is grounded via a resistor _R4 , and the collector is connected to the input terminal of the power supply voltage + _V1 .

The switches S ₁ , S ₂ , and S ₃ are all open (off) during the high level period of the input switching signal.
The switch S ₁ is configured to be closed (turned on) during the low level period, and the output rectangular wave i of the FF 49 is applied to the switch S 1 as a switching signal, while the switches S ₂ and S ₃ apply the rectangular wave i to the inverter 68. The configuration is such that a rectangular wave with inverted polarity is applied as a switching signal.

Therefore, by outputting the rectangular wave i shown in FIG. 9F from the FF 49, the switch _S1 is turned on at the falling edge of the rectangular wave i, and the switch
Since S ₂ and S ₃ are turned off, the power supply voltage decreases from this point on.
V ₁ is applied to capacitor C via resistor R ₁ and switch S ₁ to charge capacitor C. After a predetermined period of time has elapsed, switch S ₁ is turned off and S ₂ and S ₃ are turned on, respectively, at the rise of the rectangular wave i. From this point on, the charge in capacitor C is transferred to switch S ₂ and resistor R _{2 .} At the same time, the terminal voltage at the time of discharging of the capacitor C is the switch S ₃ and the transistor constituting the emitter follower.
The impedance is converted from the emitter of the transistor Tr through each Tr, and the contact S of the switch 41
Output to. Note that as time passes, the terminal voltage of capacitor C when discharging gradually decreases according to a predetermined discharge time constant determined by the values of resistor R ₂ and capacitor C, but one end of resistor R ₂ Since it is connected to the +V ₂ input terminal, it is close to the power supply voltage +V ₂ and will never have a value lower than this.

Here, the power supply voltages +V ₁ and +V ₂ satisfy the relationship V ₁ >V ₂ , but the values of both are determined depending on the devices used. It goes without saying that a desired discharge curve can be obtained by varying the discharge time constant.

In this way, a signal having a waveform as shown in FIG. 9G is applied from the motor drive waveform forming circuit 67 to the terminal N of the switch circuit 43 via the switch 41 and the motor drive amplifier 42, respectively. The switch circuit 43 is configured to receive the output rectangular wave i of the FF 49 as a switching signal.
The rectangular wave i is configured to be connected to the terminal N during the high level period and to the terminal S during the low level period.

Therefore, during the high level period of the rectangular wave i (here, 2 field periods), the output signal of the motor drive waveform forming circuit of + _V2 or more is applied to the capstan motor 20 as shown in FIG. The push-tan motor 20 rotates, and when it starts up, a relatively high voltage of +V ₁ is applied, so it starts with high torque, and just before the fall of the rectangular wave i, a relatively low voltage of +V ₂ is applied. Therefore, the tape 18 is not accelerated beyond a certain speed despite rapid startup. The magnetic tape 1 is rotated by the rotation of the capstan motor 20.
8 is made to run, and a normal reproduced image is obtained during this period.

In the next low level period of the rectangular wave i, the switch circuit 43 is switched to the terminal S side, and a reverse voltage is applied to the capstan motor 20 from the reverse voltage application circuit 66, causing the capstan motor 20 to A reverse voltage that causes the capstan motor 20 to rotate in the opposite direction is applied until the capstan motor 20 stops rotating. In this case, since a relatively low voltage of +V ₂ is applied to the capstan motor 20 immediately before the reverse voltage is applied, the rotation of the capstan motor 20 is stopped in a short time without unnecessary inertial rotation, and the magnetic Scanning of the tape 18 is stopped and a still image is obtained during this period. Here, the running stop position of the magnetic tape 18 is accurately stopped at a position shifted by a distance l ₁ from the control signal reproduction position and where noise and beats are least generated, as described above.

Thereafter, in the same manner as above, normal reproduction images for two field periods, which are performed while moving the magnetic tape 18 by two track pitches, and still images for two field periods, which are performed by stopping the running of the magnetic tape 18, are repeated alternately. As a result, a 1/2 speed slow motion reproduced image can be obtained on average as a whole, and as mentioned above, there is almost no noise bar generation. Moreover, according to this embodiment, the capstan motor 20 has a solid line a in FIG. 9G and FIG. 1A _.
Since a signal having a waveform _as shown in FIG _. As shown in FIG. 2, when the capstan motor 20 is started, it rotates at a high speed due to the generation of high torque and quickly reaches a predetermined speed. The travel time can be shortened, and an extremely good and stable slow-motion reproduced image without horizontal shaking or noise bars can be obtained.

Note that the frequency divider 51
A frequency division ratio is set, a still image playback period is set, and slow motion playback at a desired speed is performed. For example, in the case of 1/3 speed slow motion reproduction, the frequency division ratio of the frequency divider 51 is set to 1/3,
The signals f and g shown in FIGS. 9B and 9C are signals with a 6-feed period, and the signal i shown in FIG. 9F is at a high level for 2 field periods and at a low level for 4 field periods. As a result, normal playback is performed during the 2nd field period, still image playback is performed during the 4th field period, and 1/3 speed slow motion playback is performed as a whole.

Incidentally, during recording in the magnetic recording/reproducing apparatus shown in the second figure, the switches 26, 28, and 36 are respectively connected to the contact P, the switch circuit 43 is connected to the terminal N, the switch 41 is connected to the contact N, and the input terminal 11 is connected to the contact P.
The video signal etc. that entered the video head 13a,
13b, the output signal of MM24 is recorded as a control signal by control head 27, and the output signal of MM25 is applied as a sampling signal to sampling hold circuit 29, but a detailed explanation of this recording will be given in the apparatus of the present invention. Since it is not directly related to the gist of the article, it is omitted.

Incidentally, in the above embodiment, a signal having the waveform shown in FIG. 9G, which utilizes the discharge characteristics of the capacitor C, is applied to the capstan motor 20 as a drive signal _. When the wave is applied to the capstan motor 20, the time versus running distance characteristic of the magnetic tape 18 becomes as shown by the broken line _b in Figure B, and the time versus running speed characteristic of the magnetic tape 18 becomes the same. Dashed line in diagram C
It becomes as shown in _c .

As described above, the slow motion playback device of the present invention uses the capacitor terminal voltage when the capacitor is discharged as the drive signal applied to the capstan motor when the tape-shaped recording medium is running, and uses the capacitor terminal voltage at a relatively high level when starting up. In addition, since the waveform is formed at a relatively low level just before the rotation stops and slow motion regeneration is performed, when the capstan motor starts, it quickly reaches the specified speed, and after starting, the torque gradually decreases. Because of this, the tape-shaped recording medium does not accelerate beyond a certain speed despite a rapid rise, and unnecessary inertial rotation can be prevented when stopping, thereby shortening the stopping time and stopping the tape-shaped recording medium at a predetermined position. As a result, horizontal shaking of the screen and noise generation can be eliminated, and extremely good and stable slow motion reproduction can be performed.In particular, it is possible to use the discharge waveform of the capacitor as the drive signal mentioned above. Therefore, the present invention has the advantage of being able to perform almost ideal slow motion reproduction with a simple configuration.

[Brief explanation of the drawing]

1A to 1C are diagrams showing a comparison of the drive voltage waveform of the capstan motor, time vs. tape running distance characteristics, and time vs. tape running speed characteristics of the conventional device and the device of the present invention, respectively, and FIG. 2 is a graph showing the device of the present invention 3A to 3E are signal waveform diagrams for explaining the operation of FIG. 2, FIG. 4 is a track pattern diagram for explaining how tracks are recorded, and FIG. 5 is a block system diagram showing one embodiment. Figure 6 shows the relationship between the head scanning locus and the track during still image playback, Figure 6 shows the playback level during still image playback, and Figure 7 shows the tape stop position where no noise bar occurs during still image playback. The explanatory diagrams, FIGS. 8A to 8F, are signal waveform diagrams of each part of FIG. 2 during still image reproduction, and FIGS. 9A to G are signal waveform diagrams of each part of FIG. 1
FIG. 0 is a circuit diagram showing an embodiment of the main part of the device of the present invention. 20... Capstan motor, 27... Control head, 42... Motor drive amplifier, 43... Switch circuit, 49... Flip-flop (FF), 52... Monostable multivibrator (MM), 66... ...Reverse voltage application circuit, 67
...Motor drive waveform forming circuit, S ₁ , S ₂ , S ₃ ...
...Switch, C...Charging/discharging capacitor, Tr...
…NPN transistor, R ₁ … Charging resistor, R ₂ …
...Discharge resistor.

Claims (1)

[Claims] 1. In a slow-motion playback device that performs slow-motion playback by intermittently driving a tape-shaped recording medium by intermittently driving a capstan motor, when the tape-shaped recording medium is running, the capstan motor is The drive signal to be applied uses the capacitor terminal voltage when the capacitor is discharged, and is at a relatively high level at startup, and
A slow motion reproducing device characterized by forming a waveform at a relatively low level immediately before rotation stops and performing slow motion reproduction.