JPH02197280A - Motor drive speed control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a drive speed control device for a motor used as a power source for a cassette player or the like.

BACKGROUND ART 2 Vane In recent years, motor drive speed control devices have been required to respond to the trend of thinner equipment.

An example of a conventional motor drive speed control device will be described below with reference to the drawings.

FIG. 2 is a partial cross-sectional view of a cassette player mechanism in operation utilizing a conventional motor drive speed control system. In FIG. 2, 1 is a rotor provided in a motor for driving the mechanism. A belt 2 is placed between the rotor 1 and the flywheel and transmits the rotational force of the motor to the flywheel. Reference numeral 3 denotes a reflector plate attached to the rotor 1, which is provided with radial reflective portions and non-reflective portions alternately. Reference numeral 4 denotes a rotation detector consisting of a light emitting diode 4b and a phototransistor 4a, and when the light emitted from the light emitting diode 4b is reflected or not reflected by the reflective part or non-reflective part of the reflector plate 3, the rotor 1 A light pulse corresponding to the rotation speed of is input to the optical transistor 4a. Reference numeral 6 denotes a servo 3 page circuit which uses the output of the optical transistor 4a as an input signal to control the speed of the motor. 6 is a motor that is the power source of the mechanism. 7 is a power source for the motor 6, the servo circuit 6, and the light emitting diode 4b. 8 is a flywheel. 9 is a capstan, which gives a constant speed to the tape. 10 is the mechanism frame.

The operation of the motor drive speed control device configured as described above will be described below.

First, the mechanism is in an operating state, and power is supplied to the motor 6 from the power supply 7 via the reservo circuit 6, and the generated rotational torque is transmitted from the rotor 1 to the flywheel 8 through the belt 2, and from the coaxial capstan. 9 can be rotated to run the tape. At this time, the light from the light emitting diode 4b is applied to the reflector plate 3 attached to the rotor 1, and the reflected light is picked up by the optical transistor 4a to detect the rotation speed of the rotor 1, and the output is fed back to the servo circuit 5. By doing so, the rotational speed of the motor 60 can be kept constant.

Problems to be Solved by the Invention However, in the conventional configuration as described above, the frequency of the input signal to the servo circuit has a limit determined by the detection resolution of the rotation detector, so the response accuracy of the speed control device as a whole is insufficient. The problem was that it was not.

The present invention solves the above-mentioned problems and provides a motor drive speed control device with sufficiently improved control responsiveness.

Means for Solving the Problems In order to solve the above problems, the motor drive speed control device of the present invention is provided with a sub-rotor that is smaller in diameter than the rotor and equipped with a reflector, separate from the rotor of the motor main body, and that controls the rotation of the sub-rotor. is detected by a rotation detector consisting of a light emitting diode and a phototransistor, and the servo is applied based on the detection output.

Function: The motor drive speed control device of the present invention provides a sub-rotor with a smaller diameter than the rotor, separate from the rotor attached to the motor body, and sends input signals to the servo circuit through a reflector provided on the sub-rotor. By using this method, it is possible to obtain a rotation detection signal from the sub-rotor, which is faster than the main rotor, and the frequency of the rotation signal pulse to the servo circuit can be significantly increased, ensuring sufficient control response accuracy of the control device. It is possible to raise it.

Embodiment Hereinafter, a motor drive speed control device according to an embodiment of the present invention will be explained with reference to the drawings.

FIG. 1 shows a partial cross-sectional view of the cassette player mechanism in operation in one embodiment of the invention. In Fig. 1, 1 is a rotor provided on the motor body, 2 is a belt for transmitting the rotational force of the motor to the flywheel, 3 is a reflection plate provided on the sub-rotor, and 4
is a rotation detector consisting of a light emitting diode 4b and a phototransistor 4a, 5 is a servo circuit which receives the output of the rotation detector 4 as an input signal, 6 is a motor, 7 is a power supply, 8 is a flywheel, and 9 is a capstan. , 10 is the frame mechanism of the mechanism.

6/, -7 The above configuration is the same as that of the conventional example. Reference numeral 11 denotes a sub-rotor having a diameter smaller than that of the main body and equipped with the above-mentioned reflector plate 3. 12
A belt is placed between the main rotor 1 and the sub-rotor 11, and is used to transmit the rotational force of the motor 6 to the sub-rotor 11.

The operation of the motor drive speed control device configured as described above will be described below with reference to FIG. 1.

In Figure 1, the mechanism is in operation and the power supply 7
Motor 6 and rotation detector 4 through servo circuit 6
Power is supplied to each of the light emitting diodes 4b, the motor 6 starts rotating, and the rotation detector 4 becomes in a state where rotation can be detected. The rotational torque of motor 6 is from rotor 1 to belt 1.
2 to the sub-rotor 11, and the sub-rotor 11
The rotational torque generated is transmitted to the flywheel 8 through the belt 2, rotating the coaxial capstan 9,
This will cause the tape to run. At this time, sub rotor 11
The light emitted from the light emitting diode 4b is applied to the reflective plate 3 provided above, and the reflected light is picked up by the phototransistor 4a, thereby detecting the rotation speed of the sub-rotor 11, and sending the output to the servo circuit 6. By feeding back, the rotational speed of the sub-rotor 11 can be kept constant, and the rotational speed of the rotor 1, which is interlocked with the sub-rotor 11 and the belt 12, that is, the rotational speed of the motor 6 can be kept constant.

As described above, according to this embodiment, the motor 6 is provided with the sub-rotor 11 having a smaller diameter than the rotor 1, and the rotation detection signal is obtained by the reflection plate 3 provided on the sub-rotor 11, thereby detecting rotation. Since the output pulse frequency of the device 4 can be increased, and the frequency of the input signal to the servo circuit 6 can be set high, the response accuracy of the speed control device can be improved. Furthermore, the sub-rotor 11 increases the inertia to the motor 6, thereby increasing the rigidity against disturbances. Furthermore, the rotation detector is installed on the sub rotor 11.
By providing it on the side, it is possible to make the mechanism significantly thinner.

Effects of the Invention As described above, the present invention provides a sub-rotor having a smaller diameter than the rotor separately from the rotor of the motor main body, a reflector plate is provided on the sub-rotor, and a rotation detector consisting of a light emitting diode and a phototransistor is mounted on the reflector plate. The motor drive speed is controlled by applying feedback to the servo circuit using the output signal of the rotation detector, which improves the response accuracy of speed control, increases the rigidity against disturbance, and makes the mechanism thin and wide. It becomes possible to aim for

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a cassette player mechanism using a motor drive speed control device according to an embodiment of the present invention, and FIG. 2 is a partial sectional view of a cassette player mechanism using a conventional motor drive speed control device. FIG. 1...Rotor, 3...Reflector, 4...
... Rotation detector, 6 ... Servo circuit, 6.
...Motor, 11...Sub rotor, 12.
·····belt. Name of agent: Patent attorney Shigetaka Awano and one other person

Claims (1)

[Claims] A rotor provided on the rotating shaft of the motor body, a sub-rotor having a smaller diameter than the rotor to which rotational force from the motor body is transmitted by a belt placed around the outer periphery of the rotor, and a sub-rotor provided on the surface of the sub-rotor. a multi-pole reflector; a rotation detector arranged opposite to the reflector and comprising a light emitting diode and a phototransistor for detecting the rotation of the sub-rotor; and an output of the rotation detector used as input to control the rotation speed of the motor body. A motor drive speed control device characterized by comprising a servo circuit.