JPH0610908B2 - Fast forward rewind device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fast-forward rewinding device such as a video tape recorder, and in particular, it can wind up faster than before,
Moreover, the end of the tape is not forced.

[Conventional technology]

Regarding a conventional fast-forward rewinding device of this type, rewinding will be described with reference to FIG. In FIG. 5, the magnetic tape 20 runs between the take-up reel 18 and the supply reel 28, and the transparent leader tape 19 is maintained at the end of the magnetic tape 20.

In the vicinity of the take-up reel 18, a light emitting diode 15 for detecting the leader tape 19 and a phototransistor 14 are provided.
Are arranged to face each other. The light emitting diode 15 and the phototransistor 14 constitute a winding side end detector, and the light emitted from the light emitting diode 15 is transmitted through the leader tape 19 and is received by the phototransistor 14, and the phototransistor 14 is turned on. Then, the end of the magnetic tape 20 on the winding side is detected, and the output of the phototransistor 14 controls the second controller 32 to be turned off.

Similarly, the light emitting diode 25 and the phototransistor 24 are also disposed in the vicinity of the supply reel 28 so as to face each other, and the light from the light emitting diode 25 is transmitted through the leader tape 19 in the vicinity of the supply reel 28 to cause the phototransistor. Two
When the phototransistor 24 is received at 4 and turned on, the first controller 31 is turned off.
The light emitting diode 25 and the phototransistor 24 constitute a supply side end detector.

The take-up reel 18 is fitted on the take-up reel stand 11, and is rotated clockwise by the take-up side rail 13. Take-up side motor 1 which is a drive unit of take-up reel stand 11
A power source 51 is controlled by the start switch 41 and the first controller 31 to be supplied to the power source 3.

On the other hand, reference numeral 21 denotes a supply reel base, which is the supply reel base 2.
The supply reel 28 is fitted to the unit 1. The supply reel base 21 is driven by a supply side motor 23 which is a driver. The supply-side motor 23 has a second controller 32,
It is connected to a power source 52 via a start switch 42 so that power is not supplied during winding.

In fast-forwarding, the first controller 31, the start switch 41, and the power supply 51 supply power to the winding-side motor 13 and stop supplying power to the supply-side motor 23 in the same configuration as in rewinding.

Further, at the end of the fast-forwarding tape, the light emission reaches the phototransistor 24 through the leader tape 19, and the phototransistor 24 is energized.

In such a conventional fast-forward rewinding device, when the light emission of the light emitting diode 15 is cut off by the magnetic tape 20 when the start switch 42 is closed, the phototransistor 14 is off and the second controller 32. Is closed, the power supply 52 is energized to the supply side motor 23, the supply reel base 21 is driven, and the magnetic tape 20 is rewound onto the supply reel 28.

Then, the magnetic tape 20 comes to the end, and the take-up reel 18
The light of the light emitting diode 15 passes through the leader tape 19 on the side, and the phototransistor 1 passes through this leader tape 19.
When the light is received at 4, the phototransistor 14 is turned on, the second and controller 32 are turned off, the rotation of the supply side motor 23 is stopped, and the rewinding is completed.

Since the fast-forwarding is performed by the winding-side motor 13 in the same manner as the rewinding, the description is omitted.

In such a conventional fast-forward rewinding device, it takes about 200 seconds to rewind the magnetic tape. If the voltage of the power supply 52 is doubled, the rotation speed also increases,
You will be able to rewind in seconds.

However, in this case, even if the leader tape 19 transmits the light of the light emitting diode 15 to operate the phototransistor 14 and cut off the second controller 32, the supply reel 28
Is rotated by inertia, for example, the leader tape 19 is 20 cm
What was stopped by rewinding will stop after pulling out 80 cm.

At this time, if the leader tape 19 is only 50 cm, problems such as tape cutting occur. Therefore, it is necessary to reduce the speed of the tape before the end of the tape to prevent the tape from being cut.

On the other hand, there are many types of tape so that the length of the tape can be selected according to the user's request. FIG. 6 shows the relationship of the winding time with respect to the rotational speed ratio between the supply reel and the take-up reel for three kinds of tapes having different lengths. As is clear from this figure, when deceleration is started when the rotation speed ratio reaches 1.75, the 60-minute tape can be wound faster than before, but the 90-minute and 120-minute tapes have a total length of 1 Since the deceleration will start when the amount of / 3 to 1/4 is left, fast winding was not possible.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a fast-forward rewinding device that enables various tapes to be quickly wound and can be cut without cutting the tapes.

[Means for solving problems]

The fast-forward rewinding device according to the present invention includes first means for detecting a change in the number of revolutions of the supply reel during a predetermined rotation period of the take-up reel, and second means for outputting a deceleration signal when the change in the number of revolutions reaches a predetermined value. And a control means for decelerating the driver according to the deceleration signal. It should be noted that the change in the number of revolutions of the supply reel is a change in the number of revolutions with time, that is, a value of several minutes. It uses the rotation period of.

[Action]

In the present invention, when the change in the number of revolutions of the supply reel or the take-up reel reaches a predetermined value during a predetermined rotation period, the second means generates a deceleration signal, and the control means uses the deceleration signal to control the rotation speed of the driver. Lower.

〔Example〕

An embodiment of a fast-forward rewinding device according to the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the structure of the embodiment. In FIG. 1, the same parts as those in FIG. 5 are denoted by the same reference numerals, and the parts different from those in FIG. 5 will be mainly described.

In FIG. 1, the following parts are added to the configuration of FIG. That is, the reflector 27 is attached around the supply reel base 21, and the light emitting diode 22
The black and white light is reflected so that it is reflected four times in one rotation.

The light reflected by the reflector 27 is reflected by the phototransistor 26.
The light is received by the light emitting diode 22, the phototransistor 2
6, the reflector 27 constitutes a supply side rotation detector.

Similarly, the reflector 17 is also provided on the outer peripheral surface of the winding stand 11.
Is attached. This reflector 17 is a light emitting diode 1
It is painted in black and white so that the light emitted from No. 2 is reflected four times in one rotation. The light reflected by the reflector 17 is received by the phototransistor 16, and the light emitting diode 12, the phototransistor 16 and the reflector 17 constitute a winding side rotation detector.

Reference numeral 71 is a rotation speed change detecting means, which obtains information on the rotation speeds of the supply reel 28 and the take-up reel 18 from the outputs of the phototransistor 16 and the phototransistor 26, and outputs the rotation speed change detection means in a predetermined rotation period of the take-up reel 18. A change in the number of rotations of the supply reel 28 is detected and output.

The deceleration signal output means 72 outputs the deceleration signal to the third controller 73 when the output of the rotation speed change detection means 71 reaches a predetermined value, and the third controller 73 outputs the deceleration signal to output the output signal 6
00 or 601 to reduce the voltage of the power supply 62 or 61, and the supply side motor 23 or the winding side motor 13
Is designed to reduce the number of rotations of.

The power supplies 61 and 62 are used in place of the power supplies 51 and 52 shown in FIG. 5, and are of variable voltage type. Other configurations are the same as in FIG.

Next, the operation of this embodiment will be described for the case of rewinding. When the number of rotations of the supply reel 28 is n _T [rps], the output of the phototransistor 26 is 4 × n _T [Hz]. Now, if the supply reel rotates 5 times during the reference period, 5 × 4 ×
A reference period is set by counting n _T pulses.

On the other hand, the count value of the first reference period in which the output of the phototransistor 16 is counted by another counter in this reference period is n _S1 , the count value of the second reference period is n _S2 , and n in sequence.
_{If S3} , n _S4 ... n _SK , n _{S (K + 1)} , the change in rotation speed Δ _n
Is represented by Δn _k = n _{S (K + 1)} −n _SK . FIG. 2 shows the change in Δn.

Therefore, if Δn becomes larger than the predetermined value, it can be known that the end of the magnetic tape 20 is approaching. The rotation speed change detecting means 71 outputs a deceleration signal to decrease the rotation speed of the motor 23 on the supply side when Δn becomes larger than a predetermined amount. FIG. 7 shows the relationship between the rotational speed change and the winding time for three types of tapes having different lengths. As is clear from this figure, if the change in rotation speed Δn = 0.07 is used as the deceleration start point, the tape can be transported at high speed to the vicinity of the end regardless of the tape length. Explaining in comparison with FIG. 6,
For the 120-minute tape in Fig. 6, the pre-winding time was 8
While the deceleration signal is generated at the time of 7%, the present invention shown in FIG. 7 requires fast-forwarding and rewinding at high speed up to the time of 94% of the total winding time. The time can be shortened.

As a specific example, the reference period is set to 5 winding reels. However, if a smooth tape feeding system can be realized, the number of rotations is 3
There is no problem in reducing the number to twice.

FIG. 3 is a time chart of the rotation speed change detection means 71, and FIG. 4 is a block diagram showing a concrete configuration as an example of the rotation speed change detection means. Reference numeral 100 in FIG. 3A indicates a pulse output from the phototransistor 26 as the supply reel 28 rotates. As shown in FIG. 3, the signal obtained by dividing the frequency by 1/40 when the reference period is 5 rotations as in the above specific example is shown in FIG.
It is 101 of (b).

Next, a load pulse 111 (Fig. 3 (c)) indicating the change point of the signal 101 in Fig. 3 (b) and a reset pulse 112 (Fig. 3 (d)) slightly delayed are created.

The signal 110 in FIG. 4 is a pulse output from the phototransistor 16 as the take-up reel 18 rotates.
0 is a counter. The number of bits of this counter 120 is determined by the maximum value of the output of the phototransistor 16 input at the time shown in FIG. 3 (c).

The down counter 121 is a down counter having the same number of bits as the load pulse 111, and the count content is loaded according to the same load pulse 111 as the counter 120.

Now, when the content of the counter 120 becomes 0 (zero), a carry is output, and thereafter, the counter 123 operates by the output of the AND circuit 122 which ANDs the carry signal and the output pulse 110 of the phototransistor 16. That is, the number of pulses of the counter 123 is the increased number of pulses, which indicates a change in the number of revolutions.

The comparator 124 outputs the output 113 to the latch circuit 125 when the count number of the counter 123 reaches or exceeds a predetermined value. The latch circuit 125 latches the output 113 of the comparator 124, and its output signal 114 is used to reduce the motor rotation speed.

The carry signal output from the down counter 121 is input to the AND circuit 131 via the inverter 130. The AND circuit 131 ANDs the output of the inverter 130 and the output pulse of the phototransistor 16 and outputs the AND to the CK terminal of the down counter 121.

The present invention described above is not limited to video tape recorders, but can be generally applied to fast and complete winding of long objects.

〔The invention's effect〕

As described above, according to the present invention, the number of rotations of each reel stand is adjusted by providing a reflector pair on a part of the supply reel stand and the take-up reel stand, and combining the light projecting means and the light receiving means on each reel stand. In addition to enabling detection, a deceleration signal is generated when a change in the number of revolutions of the other reel stand reaches a predetermined value during a predetermined rotation period of the supply reel stand or the take-up reel stand, and based on that, a supply reel stand or winding Since the take-up reel base is decelerated, there is no fear of tape cutting even for tapes of different lengths, and fast feeding and rewinding can be performed at high speed near the end.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the fast-forward rewinding device of the present invention, and FIG. 2 shows the relationship between time and change in the number of revolutions of the supply reel or take-up reel for explaining the operation of the fast-forwarding rewinding device. FIG. 3 is a diagram showing signals of respective parts of the rotational speed change detecting means in the fast-forward rewinding device, and FIG. 4 is a block diagram showing a concrete configuration of the rotational speed change detecting means.
FIG. 5 is a perspective view of a conventional fast-forward rewinding device. FIG. 6 is a view showing the relationship of the winding time with respect to the rotation speed ratio of the supply reel and the winding reel, and FIG. 7 is a rotation speed change and the winding time. It is a figure which shows the relationship of. 11 ... Winding reel stand, 12, 15, 22, 25 ... Light emitting diode, 13 ... Winding side motor, 14, 16, 2
4, 26 ... Phototransistor, 17, 27 ... Reflector, 18 ... Take-up reel, 19 ... Leader tape, 20
...... Magnetic tape, 21 …… Supply reel stand, 23 …… Supply side motor, 28 …… Supply reel, 31 …… First controller, 32 …… Second controller, 61,62 …… Power supply, 71
...... Rotation speed change detection means, 72 ...... Deceleration signal output means,
73 ... Third controller. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A supply reel base which is rotationally driven by a drive to supply a tape, a supply side rotation speed detecting means for detecting a rotation speed of the supply reel base, and a drive which is rotationally driven to wind a tape. A take-up reel stand, a take-up side rotational speed detecting means for detecting the number of revolutions of the take-up reel stand, a supply-side end detecting means provided in the vicinity of the supply reel stand for detecting a supply-side end of the tape, A winding-side end detecting means provided near the take-up reel stand for detecting the winding-side end of the tape, and the winding-up end when the supply-side end detecting means detects the end of the tape during fast-forwarding of the tape. A first controller for stopping the drive of the reel base, and a drive unit of the supply reel base when the winding-side end detecting means detects the end of the tape when rewinding the tape. A second controller for stopping the rotation, a first means for detecting a change in the number of revolutions of the supply reel base during a predetermined rotation period of the take-up reel base, and a deceleration when the output of the first means reaches a predetermined value. Second means for outputting a signal, and third means for reducing the rotation speed of the drive unit of the take-up reel base or the supply reel base in response to the deceleration signal
Fast-forwarding and rewinding device with a controller.