JPS649836B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a speed control device for a rewinding machine, which is most suitable for tape recorders and the like.

(Prior Art) Conventionally, for example, when driving a rewinding machine for fast forwarding or rewinding a tape in a tape recorder, the tape speed is increased in order to complete rewinding in a short time. For example, when fast forwarding or rewinding a tape in a tape recorder, the supply reel (hereinafter referred to as
Equipped with a SUP motor and a T.UP motor that respectively drive the take-up reel (also referred to as the SUP reel) and the take-up reel (hereinafter referred to as the T.UP reel) that winds the tape, and controls the rotational drive of the two motors. By doing so, the tape speed is kept constant and the tape tension is kept constant to achieve smooth fast forwarding or fast rewinding. For example, during fast forwarding of a tape, the rotational speed of the SUP motor and T.UP motor must be constantly controlled. Conventionally, controlling the rotation speed of the SUP motor to keep the tape speed constant has been done by installing a rotatable detection roller in the tape running area, and determining the tape speed from the pulse output generated when the detection roller rotates in conjunction with the tape. They were trying to detect this and stabilize the tape speed. In other words, when the detection roller rotates in conjunction with the tape, the detection signal obtained from the pulse output from the detection roller is used as a negative feedback signal.
It was sent to the SUP motor to control the rotation speed. The rotational force F of the detection roller is the product of the tape tension T and the friction force μ, and can be expressed as F=μT. Further, although the detection roller is rotatable, a mechanical loss M _L increases depending on the tape speed. Therefore, when the tape speed is high, such as when fast forwarding or rewinding the tape,
Since the mechanical loss M _L increases, it can be seen that a predetermined tape tension T is required in order to overcome this mechanical loss M _L and allow the detection roller to rotate in conjunction with the tape. If an air layer is created between the roller and the tape during fast forwarding, or if the tape tension T is weakened and the detection roller does not move in conjunction with the tape, the detection signal generated from the detection roller will act as a positive feedback signal. , the tape speed is determined to be slow and the SUP motor is controlled to further increase its rotational speed, resulting in a runaway condition.

(Problem to be Solved by the Invention) As described above, the tape speed control by the detection roller has a tape speed that does not increase the mechanical loss of the detection roller, and a non-cooperation with the tape due to the mechanical loss of the detection roller. If this condition is not met, the device that is supposed to stabilize the tape speed will instead use control to weaken the tape tension and wind the tape. cause such fear.

The present invention was made in view of the above circumstances, and the detection roller is removed from the speed servo system.
It is an object of the present invention to provide a speed control device for a rewinding machine that can be applied even when the winding speed of a member to be wound is high and the winding tension is low.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention inputs the output of the rotation speed detection circuit on the winding side to the rotation speed correction circuit, and corrects the rotation speed. The circuit is configured to correct output fluctuations and provide feedback to the supply side.

(Function) By employing the above configuration, the tape speed can always be kept constant.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a speed control circuit in a tape recorder. In Figure 1, SUP motor M ₁ and T.UP motor M ₂ are not shown, but SUP
It shall have a reel and a T.UP reel. It is also assumed that the SUP reel and the T.UP reel are connected by a tape, and that the tape does not slacken due to the tension control action of the T.UP motor _M2 that drives the T.UP reel. _A1 is a SUP motor drive amplifier that is a motor drive amplifier for driving the supply side motor _M1 , and it generates a speed reference signal that generates a reference signal for the tape running speed, and the output of the rotation speed correction circuit FBC3, which will be described later. The rotation speed correction output is input, and the drive control of the SUP motor _M1 is performed so that the tape speed is constant. _A2 is the T.UP motor drive amplifier, which inputs the tension reference signal that sets the torque of the T.UP motor and the output of the tension feedback circuit FBC1, which will be described later, and generates a signal that keeps the tape tension constant. Outputs and controls the drive of T.UP motor _M2 . The tension feedback circuit FBC1 detects how much the current tape tension deviates from the reference value due to the relative torque between the T.UP motor _M2 and the SUP motor _M1 , etc., and brings it closer to the reference value. A signal is output and input to the T.UP motor drive amplifier _A2 . T.UP motor rotation speed detection circuit, which is the motor rotation speed detection circuit on the winding side
FBC2 detects the rotation speed of T.UP motor _M2 and outputs it as a rotation pulse. Rotation speed correction circuit FBC3
inputs the output of the T.UP motor rotation speed detection circuit, outputs a DC level for correcting the SUP motor rotation speed according to the input, and inputs it to the SUP motor drive amplifier. Above SUP motor drive amplifier A ₁ , T.UP motor drive amplifier A ₂ ,
Tension feedback circuit FBC1 and T.UP
Since each circuit of the motor rotation speed detection circuit FBC2 is known, a detailed explanation thereof will be omitted, and the details of the rotation speed correction circuit FBC3 will be explained with reference to FIG. In Fig. ₂ , the output of the T.UP motor rotation speed detection circuit FBC2, which is composed of a light emitting element 2 and a light receiving element 3 that are arranged opposite each other, is detected via an encoder 1 provided on the motor shaft of the T.UP motor M2. Let the rotation pulse be V ₃ . 4 is a D/A converter, and the tape winding diameter on the T.UP reel is
It is thought that it is proportional to the number of rotations of the T.UP reel until the winding diameter is reached, so by inputting the rotation pulse V ₃ and counting the pulses, the T.UP
Outputs a DC level V ₄ proportional to the number of tape turns on the reel. 5 is a tape selector;
Since the tape winding diameter is considered to be equivalent to the number of tape turns multiplied by the tape thickness, input the DC level V ₄ mentioned above and calculate the resistance values R ₁ , R ₂ ,
Corrected by _R3 , a DC level _V5 proportional to the winding diameter of the tape on the T.UP reel is output according to the tape thickness. Note that the resistance values of resistors R ₁ , R ₂ , and R ₃ of C-60, C-90, and C-120 are set to R ₁ < R ₂ < R ₃ so that they are inversely proportional to the tape thickness. put.
6 is a calculating machine such as a multiplier, and T.UP motor M ₂
The rotation pulse V ₃ is input to input Y, the DC level V ₅ is input to input X, and the output obtained by multiplying both is Z=X・Y.
Output. 7 is a smoothing circuit which inputs the output Z, smoothes the pulsed output Z, converts it to a DC level, and inputs it to the SUP motor drive amplifier _A6 .

The operation of the speed control device configured as above will be explained. In Figure 1, the operation of SUP motor drive amplifier (hereinafter also referred to as SUP amplifier) A ₁ causes SUP motor M ₁ to rotate and feed out the tape, and the T.UP motor drive amplifier (hereinafter referred to as T.UP
T.UP motor by operation of _A2 (also called amplifier)
Regarding the case where M ₂ rotates and winds up the tape,
Referring to the flowchart of FIG. 3, the tape speed will be explained in three ways: normal, fast, and slow. If the tape speed is normal, the T.UP motor
_M2 inputs a tension reference signal that is set to keep the tape tension constant according to the tape winding diameter of the T.UP reel, which gradually changes.
A rotation pulse V ₃ is obtained by a light receiving element ₃ which is driven by a T.UP amplifier A 2 and is placed opposite a light emitting element 2 via an encoder 1 . The rotation of T.UP motor _M2 is
In inverse proportion to the winding diameter of the T.UP reel, the rotational speed is high at the beginning of winding, and the rotational speed decreases as it approaches the end of winding, so the frequency of the rotation pulse V ₃ is also high at the beginning of winding and increases as it approaches the end of winding. Therefore, it is getting lower. That is, the rotation pulse shown in FIG. 4A is obtained.
As shown in FIG. 4A, the pitch of the rotational pulses _V3 is dense at the beginning of winding, and becomes sparse as it approaches the end of winding. When the rotation pulse V ₃ is input to the D/A converter 4, the D/A converter 4 counts the rotation pulse V ₃ and calculates the number of turns proportional to the number of tape turns on the T.UP reel.
A DC level V ₄ is output, and the winding diameter output voltage V 5 is output after being corrected to one of the resistance values R ₁ , R ₂ , and R ₃ according to the tape thickness selected by the tape selector ₅ .
FIG. 4B shows the relationship between the winding diameter and the winding diameter output voltage _V5 . Winding diameter output voltage V ₅ above, rotation pulse
When V ₃ is applied to the input terminals X and Y of the multiplier 6, the output Z=X·Y of the multiplier 6 is obtained as a pulse output as shown in FIG. 4C. As this pulse output Z moves from the beginning of winding to the end of winding, the potential of the pulse gradually increases,
At the same time, the pulse pitch changes from dense to sparse, so the energy of the pulse output Z at each winding diameter position is uniform. Therefore, the output V ₇ of the smoothing circuit 7 obtained by integrating the pulse output Z is:
As long as the tape is running at the specified speed, it remains constant regardless of the winding diameter of the T.UP reel. FIG. 4D shows the relationship between the output V ₇ of the smoothing circuit 7 and the winding diameter. Therefore, the output of the rotation speed correction circuit FBC3 remains constant as long as the tape is running at the specified speed.
SUP motor M ₁ driven by SUP motor amplifier A ₁
Since its rotational drive is controlled to match a preset tape speed reference signal, the tape speed can be kept constant. Next, to explain the operation when the rotation of the SUP motor _M1 becomes higher than the specified value in the flowchart of Fig. 3, and the tape speed becomes faster, the tape tension becomes lower because the tape feeding speed becomes faster. In the tension control system, a signal is sent from the tension feedback circuit FBC1, which operates through the T.UP amplifier _A2 to increase the rotational speed of the T.UP motor to keep the tension constant. At this time, the input Y of the multiplier 6 is greater than the rotation pulse of the T.UP motor _M2 at the specified tape speed with respect to the input X that inputs the winding diameter output voltage _V3 indicating the winding diameter of the tape. Since the rotation pulse has a high frequency, the energy balance of the output pulse Z of the multiplier 6 is lost, and the output V ₇ of the smoothing circuit 7 to which the output pulse Z is input has an output potential higher than a certain standard. When an output V ₇ higher than this certain standard is applied to the negative terminal of SUP amplifier A ₁ , the SUP amplifier
A ₁ will control the SUP motor M ₁ to lower its rotation speed. With the above-described operation, the rotation of the SUP motor _M1 can be controlled to be instantaneously lowered even when the rotation is about to increase, and the tape speed can be kept constant. Next, when the rotation of the SUP motor _M1 decreases and the tape speed begins to slow down, the tension control system detects that the tape tension is increasing and sends a signal from the tension feedback circuit FBC1.
It operates via T.UP amplifier A ₂ to reduce the rotation of T.UP motor M ₂ and keep the tension constant.
At this time, the input Y of the multiplier 6 is greater than the rotation pulse of the T.UP motor _M2 at the specified tape speed with respect to the input X that inputs the winding diameter output voltage _V6 indicating the tape winding diameter. Since the rotation pulse has a low frequency, the energy balance of the output pulse Z of the multiplier 6 is lost, and the output V ₇ of the smoothing circuit 6 to which the output pulse Z is input has an output potential lower than a certain standard. If the output V ₇ is lower than this certain standard,
When applied to the negative terminal of SUP amplifier A ₁ ,
The SUP amplifier A ₁ will control the SUP motor M ₁ to increase its rotational speed. Due to the above effects,
It is possible to control the rotation of the SUP motor M ₁ to instantly increase the rotation even if the rotation is about to decrease, thereby making it possible to maintain a constant tape speed. As explained above, as long as the tape speed is constant, the output of the rotation speed correction circuit FBC3 is constant, so the constant speed of the tape is maintained, and if the constant speed of the tape is about to be impaired, The displacement of the rotational pulse of the T.UP motor can be extracted from the output of the rotational speed correction circuit FBC3 and can be instantly controlled to achieve constant speed of the tape.

It goes without saying that the present invention is not limited to the embodiments described above, and includes various modifications within the scope of the gist of the present invention. In the above embodiment, the winding side and the supply side were specified and explained.
If one side is the supply side and the other is the take-up side depending on the purpose of fast forwarding or fast rewinding like a tape deck, both motors should be equipped with the same functions listed above to perform fast forwarding or fast rewinding. It can also be done smoothly. In this case, it is necessary to use a counter capable of addition and subtraction in the D/A converter 4 in the above embodiment. It goes without saying that the present invention is applicable not only to tape decks but also to other rewinding machines that rewind a member to be wound at a constant speed and with a constant tension. Furthermore, it goes without saying that the components in the embodiment described above can be replaced with other components having the same function. For example, in the embodiment described above, an analog multiplier was used as the arithmetic unit, but in the case of digital processing, a digital adder may be used. You may also use a container.

[Effects of the Invention] As explained above, according to the present invention, the number of rotations of the supply motor that sends out the material to be wound at a constant speed is controlled by the rotation pulse of the motor to be wound. It is possible to provide a speed control device for a rewinder that can wind up a member at high speed and with low tension. Therefore, unlike the conventional speed control device using a detection roller, the tape can be wound at high speed because it is not affected by the mechanical loss of the detection roller. The SUP motor does not run out of control due to interlocking.
Moreover, since the tape can be stably run with extremely low tape tension, excellent effects such as not damaging thin tapes can be achieved.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a speed control circuit showing an embodiment of the present invention, Fig. 2 is a block diagram explaining details of an embodiment of the rotation speed correction circuit, and Fig. 3 is an explanation of the operation of the speed control circuit. A, B, C, D are multiplier 6
Input X, input Y, output Z and output of smoothing circuit 7
FIG. 7 is a characteristic diagram showing the relationship between each of V ₇ and the winding diameter. DESCRIPTION OF SYMBOLS 1... Encoder, 2... Light emitting element, 3... Light receiving element, 4... D/A converter, 5... Tape selector, 6... Arithmetic unit, 7... Smoothing circuit.

Claims (1)

[Scope of Claims] 1. A winding device having a supply side motor that feeds out a member to be wound at a constant speed, and a winding side motor that winds up the member to be wound, which is sent out from the supply side motor, with a constant tension. A speed control device for a rewinding machine applied to a rewinding machine, comprising: a rewinding side motor rotational speed detection circuit that detects the rotational speed of the rewinding side motor; and an output signal of the rewinding side motor rotational speed detection circuit. and a D/A converter that outputs a DC voltage according to the integrated counting result, and the D/A
a rotation speed correction circuit configured with a multiplier circuit that multiplies the output of the converter by the output of the take-up motor rotation speed detection circuit, and a smoothing circuit that smoothes the output of the multiplication circuit; A motor drive amplifier that compares a reference signal and an output signal of the rotation speed correction circuit and drives the supply motor so that both output signals are balanced. Control device.