KR100222472B1 - A driving circuit of head-drum motor using an impulse generation magnet - Google Patents

Abstract

The present invention relates to a driving circuit of a head drum motor using an impulse generating magnet, and includes a magnetic signal from an impulse magnet installed in each N and S stimulus of a plurality of magnetized FG detection magnets on a rotational circumference of a rotor constituting the head drum motor. A hall sensor provided with a singular number for detecting a signal; an amplifier for amplifying the impulse signal detected from the hall sensor to a predetermined level; and a bit count unit for shaping an impulse signal output from the amplifier to generate a counting signal; An integrating circuit unit for integrating the impulse signal detected from the sensor, a zero crossing unit for zero-crossing the output pulse signal of the integrating circuit unit and detecting zero points, zero point signals and bit counts detected by the zero crossing unit Determines the counting signal according to the impulse signal input from the negative and according to the current phase of the rotating magnet of the rotor A drive control unit for determining the next drive sequence and outputting the speed control signal of the head drum motor, and applying a drive current to the corresponding magnet coil according to the next drive sequence control signal of the drive control unit, and applying the drive current to the head drum motor according to the speed control signal. The switch driving portion for controlling the rotational speed can significantly reduce the manufacturing cost of the drive circuit.

Description

Driving Circuit of Head Drum Motor Using Impulse Magnet

The present invention relates to a driving circuit of a head drum motor using an impulse generating magnet, and in particular, a magnet in a form in which an impulse generating magnet is sequentially increased one by one for each N and S stimulus on a rotational circumference of a rotor in which an FG detecting magnet is magnetized. Impulse generation that detects the impulse signal according to the inductance change from the magnetized impulse magnet through one Hall sensor and compares the number and detected waveforms of the detected impulse signals of each phase to determine the switching position and rotation speed of the head drum motor. It relates to a driving circuit of a head drum motor using a magnet.

In general, the VRL system has a very small recording size of a video signal, a track width of about 0.2-0.02 mm, a recording wavelength of about a few microns, and is recorded in the tape width direction. Therefore, during recording, it is necessary to stably control the rotation of the head drum motor so as not to change the time axis of the video signal as much as possible. In addition, in order to maintain tracking of the video track, it is necessary to keep the head drum rotation and tape running state (speed and positional relationship) as in recording.

Then, referring to the driving circuit of the head drum motor of the conventional V-Cal as described with reference to FIG. 1, a plurality of Hall sensors detecting a relative rotational position of the rotor 70A of the head drum motor 70 at a predetermined angle ( 71A, 71B, amplifiers 72A, 72B connected to the output terminals of the Hall sensors 71A, 71B to amplify the detected head position detection signal to a predetermined level, and one ends of the amplifiers 72A, 72B. The driving transistors 74A and 74B are connected to the resistors R1 and R2 to respectively apply driving voltages to the magnet coils 73A and 73B of the head drum motor 70.

The driving transistors 74A and 74B are composed of NPN transistors. A bias power supply VCC is connected to the collector terminals of the driving transistors 74A and 74B.

In addition, a plurality of magnets 76 of the FG sensor 75 which detects the speed of the head drum motor 70 are magnetized on the rotation circumference of the rotor 70A, and the magnets 76 of the FG sensor 75 are magnetized. ), A detection pattern 77 is formed.

Meanwhile, referring to the operation of the conventional head drum motor driving circuit having the above configuration, first, when the play mode or the recording mode signal is input to the V-C, an arbitrary detection voltage is applied to the hall sensor 71A during the first driving. I will let you. Then, the Hall sensor 71A inputs a detection signal according to the rotational position detection voltage of the head drum motor 70, for example, a high signal to the amplifier 72A, whereby the amplifier 72A receives the input signal. After amplifying the high signal to a predetermined level, the resistor R1 is input to the base terminal of the driving transistor 74A. Then, the driving transistor 74A is driven in accordance with the high signal input to the base end to apply a bias voltage to the magnet coil 73A of the head drum motor 70. Therefore, the magnetic flux is generated in the magnet coil 73A of the head drum motor 70 to attract the magnetic pole of the rotor (not shown), so that the head drum motor 70 rotates by a predetermined rotation angle. At this time, since the hall sensor 71B of the next phase does not perform the detection operation, the driving transistor 74B of the next phase is not driven.

However, if the rotor 70A of the head drum motor 70 rotates by a predetermined rotation angle during the process, the next phase Hall sensor 71B detects this. When the hall sensor 71B detects the magnetic signal of the rotor 70A, the amplifier 72B amplifies the input detection voltage to a predetermined level to pass the resistor R2 to the base end of the driving transistor 74B. Will be entered. Then, the driving transistor 74B is driven in accordance with the high signal input to the base end to apply a bias voltage to the magnet coil 73B of the head drum motor 70 as opposed to the magnet coil 73A. Therefore, the magnetic flux is generated in the magnet coil 73B of the next phase to push the magnetic pole of the rotor 70A, so that the head drum motor 70 rotates again by a predetermined rotation angle.

And, as the above process is repeated, the Hall sensors 71A and 71B sequentially execute the detection operation, and thus driving power is sequentially applied to the magnet coils 73A and 73B of the head drum motor 70. The head drum motor 70 continues to rotate. At this time, the magnet 76 of the FG sensor 75 mounted on the rotational circumference of the rotor 70A also rotates, so that the detection pattern 77 of the FG sensor 75 is magnetized from the magnet 76. The pulse signal is detected and input to the microcomputer 78. Then, the microcomputer 78 determines the pulse signal of the input FG sensor 75 to control the rotation speed of the currently driven head drum motor 70.

Therefore, the head drum (not shown) which is interlocked with the head drum motor 70 also rotates according to the set mode signal, and accordingly, the head mounted on the head drum plays back or records information from the video tape.

However, in the driving circuit of the conventional head drum motor as described above, since the hall sensors 71A and 71B, which are components for detecting the rotational position of the head drum motor 70, are relatively expensive components, at least a plurality of motors must be installed. As a driving circuit, the manufacturing cost accordingly increased considerably, as well as a separate specific space must be secured on the fixed printed circuit board to install the hall sensors 71A and 71B, thereby limiting the space utilization of the system.

Therefore, the present invention is invented to solve the above-mentioned disadvantages, by magnetizing in a form in which the impulse generating magnets are sequentially increased one by one for each N and S stimulation on the rotational circumference of the rotor in which the FG detection magnet is magnetized. By detecting the impulse signal according to the inductance change from the magnetized impulse magnet through the Hall sensor, and comparing the number and detected waveforms of the detected impulse signals of each phase to determine the switching position and rotation speed of the head drum motor, the head drum Since the number of installation of the Hall sensor for detecting the rotational position of the motor is significantly reduced, the object of the present invention is to provide a driving circuit of the head drum motor using an impulse generating magnet, which can significantly reduce the manufacturing cost of the driving circuit.

Another object of the present invention is to detect the rotational position of the motor using the impulse signal according to the inductance change detected from the impulse generating magnet magnetized on the rotational circumference of the rotor magnetized FG detection magnet and according to the detected switching signal Since the head drum motor can be precisely driven, the reliability of the head drum motor is also improved, thereby providing a driving circuit for the head drum motor using an impulse generating magnet.

The present invention for achieving the above object is provided with a singular hole for detecting a magnetic signal from the impulse magnets installed in each of the N, S stimulation of the FG detection magnet magnetized in a plurality of magnets on the rotation circumference of the rotor constituting the head drum motor A sensor, an amplifier for amplifying the impulse signal detected by the hall sensor to a predetermined level, a bit count unit for generating a counting signal by shaping the impulse signal output from the amplifier, and an impulse signal detected from the hall sensor. An integration circuit unit for integrating, a zero crossing unit for detecting zero points by zero-crossing an output pulse signal of the integration circuit unit, zero point signals detected by the zero crossing unit and an impulse signal input from the bit count unit. Determine the next driving sequence according to the current phase of the rotor magnet and determine the head drum Drive control unit for outputting a speed control signal of the motor, and a switching drive unit for applying a drive current to the corresponding magnet coil according to the next drive sequence control signal of the drive control unit and controlling the rotational speed of the head drum motor according to the speed control signal. It features.

1 is an explanatory diagram illustrating a driving circuit of a conventional head drum motor,

2 is an explanatory diagram illustrating a head drum motor driving circuit of the present invention;

3 is a structural diagram illustrating an embodiment in which an impulse magnet applied to the present invention is magnetized on an FG detection magnet,

4 is an explanatory diagram illustrating a head drum motor to which the present invention is applied;

5 is a flowchart of the present invention,

6 (a) is a waveform diagram showing the phase change according to the magnetic flux of the head drum motor,

(b)-(d) are waveform explanatory diagrams showing detection signals of the hall sensors corresponding to the phase of FIG. 6 (a),

7A is an output waveform of the Hall sensor detecting an impulse magnet signal,

(b) is the waveform which integrated the signal of FIG.

* Explanation of symbols for main parts of the drawings

1: Head 2: Head Drum

3: head drum motor 4: rotor

5: FG detection magnet 6: impulse magnet

7 Hall sensor 8 Amplifier

9: bit count unit 10: integral circuit unit

11: zero crossing part 12: rotating magnet

13 drive control unit 14a-c magnet coil

15: switching driver 16: trigger

17: bit counter 18: stator

19: fixed printed circuit board 20: core

TR1-TR6: Drive Transistor

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

As shown in Figs. 2 to 4, the driving circuit of the present invention includes a head drum motor 3 for driving the head drum 2 on which the head 1 of V-Cal is mounted, and the head drum motor 3. A single Hall sensor that detects a magnetic signal from an impulse magnet 6 installed in each of the N and S magnetic poles of the FG (= FREQUENCY GENERATING) detection magnet 5 that is magnetized on the circumference of the rotor 4 of the rotor 4 7), an amplifier 8 for amplifying the impulse signal detected from the hall sensor 7 to a predetermined level, and a bit count unit for shaping the impulse signal output from the amplifier 8 to generate a counting signal ( 9), an integrating circuit unit 10 for integrating the impulse signal detected from the hall sensor 7, and zero-crossing the output pulse signal of the integrating circuit unit 10 to detect zero points. The zero crossing unit 11, the zero point signals and the bit count detected by the zero crossing unit 11 By determining the counting signal according to the impulse signal inputted from the unit 9, the next driving sequence according to the current phase of the rotating magnet 12 of the rotor 4 is determined, and the speed control signal of the head drum motor 3 is output. Drive current is applied to the magnet coils 14a-14c according to the drive control unit 13 and the next drive sequence control signal of the drive control unit 13, and the rotational speed of the head drum motor 3 is adjusted according to the speed control signal. It consists of a switching driver 15 for controlling.

In addition, the bit count unit 9 includes a trigger 16 for waveform shaping the impulse signal detected from the hall sensor 7, and for example, a 4 bit counter for counting the waveform-shaped impulse signal through the trigger 16. It consists of 17.

In the switching driver 3, drive transistors TR1-TR6 for applying a test pulse signal or a driving voltage for detecting the rotation position to the magnet coils 14a-14c of each phase are connected in a constant connection method. According to the "Y" connection, respectively, the magnet coils 14a-14c are connected to each other. At this time, a bias voltage VCC is connected to the collector terminals of the driving transistors TR1, TR3, TR5, and the driving transistors TR1, TR3. The magnet coils 14a-14c of each phase are connected to a common connection point at which the emitter terminal of TR5 and the collector terminals of the driving transistors TR2, TR4 and TR6 are connected, respectively, and the driving transistor TR1 Each base end of -TR6 is connected to a drive control unit 13.

Here, the impulse magnet 6 is magnetized in each N, S stimulus of the FG detection magnet 5 magnetized on the rotational circumference of the rotor 4, wherein the impulse magnet 6 is shown in FIG. As described above, the magnet is magnetized in a sequential increment. For example, if the first impulse magnet 6 is magnetized one by one in the N and S stimuli of the FG detection magnet 5, two in the next N and S stimulus, and three in the next N and S stimulus. Up to.

In addition, the head drum motor 3 is composed of a rotor 4 and a stator 18 as shown in Figure 4, wherein the stator 18 is a fixed print installed on the lower portion of the head drum (2) Magnet coils 14a-14c are wound around the substrate 19 in the form of a core 20. The stator 18 has a predetermined gap in the opposite position of the N and S poles on its inner surface. The rotor 4 in which the rotating magnet 12 is magnetized is installed.

Next, the operation and effects of the present invention having the above configuration will be described.

First, as shown in FIG. 5, the present invention proceeds from the initial state S1 to the mode signal setting determination step S2 to determine whether the current mode signal is set. As a result of the determination during the mode signal setting determination step S2, if the mode setting signal is not set, for example, the playback mode or the recording mode signal is returned, the process returns to the previous step S1 to repeat the loop. However, if the mode setting signal is set as a result of judging during the mode signal setting determination step (S2), the drive test application step (S3) proceeds to the test current to the magnet coil of each phase in the initial stop state of the motor. Apply a signal. After the driving test application step (S3), the process proceeds to the impulse signal detection step (S4) to detect the impulse signal according to the inductance change from the magnet coil of each phase applied to detect the initial switching position of the head drum motor. Done.

That is, when the mode signal is set, the driving controller 13 drives the head drum motor 3 at a rotation speed suitable for the set mode signal. At this time, the drive current to detect the rotation position of the head drum motor 3 is performed. The signals are sequentially passed through the magnet coils 14a-14c of each phase.

For example, the driving control unit 13 turns on the driving transistor TR1 and the driving transistor TR4 when the phase is "u" through the switching driving unit 15 so that only the opposite current flows in the same magnet coil 14a. The driving transistor TR3 and the driving transistor TR2 are also turned on. In the case of the "v" phase, the driving transistor TR3 and the driving transistor TR6 of the switching driver 15 are turned on, and the driving transistor TR5 and the reverse current flow in the same magnet coil 14b. The driving transistor TR4 is also turned on. In the case of the "w" phase, the driving transistor TR5 and the driving transistor TR2 of the switching driver 15 are turned on, and only the opposite direction is applied to the same magnet coil 14c. The driving transistor TR1 and the driving transistor TR6 are turned on so that the phosphorus current flows. Then, the corresponding driving transistors TR1-TR6 of the switching driver 3 are driven in accordance with the driving control signal input to the base end. Then, a bias voltage is applied to the corresponding magnet coils 14a-14c of the head drum motor 3. Therefore, magnetic flux is generated in the corresponding magnet coils 14a-14c of the head drum motor 3 to generate the magnetic flux of the rotor 4. Rotating magnet (12) Since the pull, the head drum motor 3 is rotated by a predetermined rotation angle. Therefore, as the rotor 4 of the head drum motor 3 moves relative to the stator 18, the inductance value of the stator 18 also changes as shown in FIGS. 6A and 6C. In addition, the hall sensor 7 provided with only one stage on the fixed printed circuit board 19 sequentially detects the magnetic signal according to the changed inductance value. In this case, the hall sensor 7 is the rotor 4. The magnetic signal generated from the impulse magnet 6 provided in the N and S magnetic poles of the FG detection magnet 5 installed on the rotational circumference of is detected as shown in FIG.

On the other hand, after the impulse signal detection step (S4) proceeds to the drive sequence determination step (S5) and compares the impulse signal and the detected waveform signal detected from the Hall sensor installed in the single stage to determine the current rotor phase and determine the determination Based on the signal, the next driving sequence is determined. At the same time as the above operation, the number of pulses of the waveform signal is compared and the rotation speed control signal of the head drum motor is also output. After the driving sequence determination step S5, the driving sequence determination completion step S6 is performed to determine whether the driving sequence determination and the calculation operation of the rotational speed control signal of the motor have been completed. As a result of judging during the sequential determination completion step S6, if the current driving sequence determination and the calculation operation of the rotational speed control signal of the motor are not completed, the process returns to the previous step S5 to repeat the loop. However, when the driving sequence determination and the calculation operation of the rotational speed control signal of the motor have been completed as a result of the determination during the driving sequence determination completion determination step (S6), the process proceeds to the driving sequence and the rotational speed control execution step (S7). The magnet coil is driven according to the determined driving sequence, and the rotation speed of the head drum motor is also controlled at a constant speed according to the rotation speed control signal of the motor calculated at the same time.

That is, when the impulse signal as shown in (a) of FIG. 7 is detected by the hall sensor 7, the detected impulse signal is input to the amplifier 8 and signal amplified to a predetermined level, and then the bit count unit ( It is input to the trigger 16 and the integral circuit unit 17 of 9), respectively. Then, the trigger 16 modulates the input impulse signal and inputs it to the bit counter 17, for example, the 4-bit counter 17. Thus, the 4-bit counter 17 according to the input impulse signal. It counts and inputs the counted signal to the drive control unit 13. For example, when three impulse magnets 6 are magnetized on the FG detection magnet 5, three pulses are transmitted through the Hall sensor 7. Since the signal is detected, this 4-bit counter 17 inputs the output signal corresponding to the "4" bit to the drive control unit 13.

Meanwhile, the detection signal of the hall sensor 7 input to the integration circuit unit 10 simultaneously with the operation is integrated by the integration circuit unit 10 as shown in FIG. Will be entered. Then, the zero crossing section 11 zero-crosses the input signal of the integrated circuit section 10 and inputs the detected zero point signals to the drive control section 13.

Accordingly, the drive control unit 13 determines how many impulse numbers input through the 4-bit counter 17 exist between zero points corresponding to the phase of the rotor 4 input from the zero crossing unit 11. The comparison is judged to determine the phase of the rotor 4 currently in operation. Based on the determined phase of the rotor 4, the sequence of the magnet coils to be driven next is determined. For example, the last driving sequence of the magnet coil 14a on "u" is defined such that the impulse signal has a value of "2,2", and the magnet coil 14b on "v" which is the next driving sequence has an impulse signal of "3". If the current impulse signal is detected as a value of "2,2" in the state defined to have a value of "3", the driving controller 13 causes the magnet coil (phase) of the magnet 12 of the current rotor 4 to be "u". Recognizing that it corresponds to 14a), the next driving sequence determines the magnet coil 14b of " v ". Then, the drive controller 13 drives the head drum motor 3 by applying a drive current to the magnet coil 14b through the switching driver 15 in accordance with the determined next drive sequence.

At the same time, the driving control unit 13 compares the number of zero point signals detected during one rotation of the zero point signals inputted from the zero crossing unit 11 for a predetermined period. The current rotation speed of the head drum motor 3 is recognized and an appropriate speed control signal is applied to the switching driver 15. For example, when the number of detected zero point signals is smaller than the set number of mode signals. By increasing the driving voltage applied to the magnet coils (14a-14c) through the switching driver 15 to maintain a constant speed of the motor (3).

As described above, according to the present invention, an impulse magnet magnetized through one Hall sensor is magnetized in a form in which an impulse generating magnet is sequentially increased one by one for each N and S stimulus on a rotational circumference of the rotor in which the FG detection magnet is magnetized. Hall sensor for detecting the rotational position of the head drum motor by detecting the impulse signal according to the inductance change and determining the switching position and rotation speed of the head drum motor by comparing the number and detected waveforms of the impulse signals of each phase. Since the number of installations is significantly reduced, the manufacturing cost of the driving circuit can be significantly reduced accordingly. In addition, the present invention detects the rotational position of the motor by using the impulse signal according to the inductance change detected from the impulse generating magnet magnetized on the rotational circumference of the rotor magnetized the detection magnet of the FG sensor and according to the detected switching signal Since the head drum motor can be precisely driven, the reliability of the head drum motor is thus significantly improved.

Claims (3)

In the driving circuit of the head drum motor (3) for rotating and driving the head drum (2) on which the head of V-Cal is mounted, In a single stage to detect a magnetic signal from the impulse magnet 6 installed in each of the N, S stimulus of the FG detection magnet 5 magnetized on the rotational circumference of the rotor 4 constituting the head drum motor (3) A counting signal is generated by signal shaping the provided hall sensor 7, an amplifier 8 which amplifies the impulse signal detected by the hall sensor 7 to a predetermined level, and an impulse signal output from the amplifier 8. Integrating the bit count unit 17, the impulse signal detected from the hall sensor 7, the integrating circuit unit 10, and the output pulse signal of the integrating circuit unit 10 is zero-crossed to zero. The rotor 4 determines the counting signal according to the zero crossing unit 11 for detecting the points, the zero point signals detected by the zero crossing unit 11 and the impulse signal input from the bit count unit 17. The next driving sequence according to the current phase of the rotating magnet 12 The drive control unit 13 outputs the speed control signal of the high head drum motor 3, and the drive current is applied to the corresponding magnet coil 14a-14c according to the next drive sequence control signal of the drive control unit 13 and the speed is increased. The driving circuit of the head drum motor using an impulse generating magnet, characterized in that the switching drive unit 15 for controlling the rotational speed of the head drum motor (3) according to the control signal. 2. The driving circuit of the head drum motor using an impulse generating magnet according to claim 1, wherein the impulse magnet 6 is magnetized in each N and S stimulus of the FG detecting magnet 5 in a sequential increment. in. 2. The bit counting unit (9) according to claim 1, wherein the bit count unit (9) includes a trigger (16) for shaping the impulse signal detected from the hall sensor (7), and a bit for counting the waveform of the impulse shaped through the trigger (16). A driving circuit of a head drum motor using an impulse generating magnet, characterized in that the counter (17).

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