KR19980059128A - Frequency generator (FG) generator and method of V-Cal head drum motor - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency generator (FG) generator and method for a BC-Cal head drum motor. In particular, an abnormal magnet is formed at a fixed interval in a rotating magnet of a rotor, and the abnormal magnet is generated at the counter electromotive force of the three-phase coil. The present invention relates to a frequency generator generator and method for a V-Cal head drum motor, which obtains a frequency generator having different on and off periods by using zero crossing of spikes and counter electromotive force.

To this end, the present invention is a three-phase coil wound around the core of the state to generate a back electromotive force when the drive signal is applied, the FG generation of the BC head drum motor to generate the FG by the detection pattern formed on the rotating magnet of the rotor and the fixed printer substrate In the method, an abnormal magnetization magnet is formed in the rotating magnet at a predetermined interval, and the counter electromotive force generated from the three-phase coil during the rotation of the rotating magnet is divided into appropriate sections, and the spikes generated by the abnormal magnetization in the divided sections. The on and off periods from the zero crossing of the waveform and the counter electromotive force produce different FGs.

Description

Frequency generator (FG) generator and method of V-Cal head drum motor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frequency generator (FG) generator and method for a BC-Cal head drum motor. In particular, an abnormal magnet is formed at a fixed interval in a rotating magnet of a rotor, and the abnormal magnet is generated at the counter electromotive force of the three-phase coil. The present invention relates to a frequency generator generator and method for a V-Cal head drum motor, which obtains a frequency generator having different on and off periods by using zero crossing of spikes and counter electromotive force.

In general, the VR signal system has a very small dimension of recording a video signal, a track width of about 0.2-0.02 mm, a recording wavelength of about several microns, and is recorded in the tape width direction.

Therefore, during recording and playback, it is necessary to control the head drum rotation so as not to change as the time axis of the video signal changes.In order to maintain precise tracking control during playback, the head drum rotation and the tape running state (speed and position relationship) It is necessary to maintain it as in recording, and a frequency generator (FREQUENCY GENERAROR: hereinafter referred to as FG) is used for V-CAL for accurate speed control.

Looking at the FG generator and process as described above with reference to Figure 1, the head drum 71, the head of the V-Cal 70 is mounted, the drum motor 72 for driving the head drum 71, and A FG detection pattern 75 formed on the rotor 73 and the stator 74 side of the drum motor 72 to generate a speed pulse signal, and a sinusoidal speed pulse signal generated from the FG detection pattern 75. A hysteresis amplifier 76 for converting and amplifying a square wave into a square wave, and a microcomputer 77 for calculating the timing of the speed pulse signal input from the hysteresis amplifier 76 to control the speed of the drum motor 72.

In addition, the FG detection pattern 75 has a plurality of rotor magnets, that is, a plurality of permanent magnets on the rotational circumference of the cylindrical member formed with a plurality of permanent magnets, for example, magnets rotating in 24 permanent magnets having different polarities. And a detection pattern 80 arranged in a circle on the fixed printed circuit board 79 so as to face the magnetizing surface of the rotary magnet 78. As shown in FIG.

Here, the rotating magnet 78 is formed integrally with the rotor 73 to generate a voltage having a frequency of 1/2 the number of poles of the rotating magnet 78 each time the rotor 73 rotates, and The detection pattern 80 is formed on the stator 74 side and is integrally formed on the fixed printed circuit board 79 on which the armature coil, the position detection element, and the electronic component for driving are disposed.

On the other hand, looking at the operation of the conventional FG circuit configured as described above, when the playback mode or recording mode is set first, the microcomputer 77 drives the drum motor 72 to rotate the head drum (71).

That is, the rotor 73 rotates due to the electromagnetic action of the stator 74 and the rotor 73 of the drum motor 72, and thus the head drum 71 also rotates through the rotation shaft 81. The rotation magnet 78 of the FG detection pattern 75 integrally formed in the rotor 73 also rotates according to the rotation of the rotor 73.

Accordingly, a rotation detection voltage, that is, a sinusoidal speed pulse voltage is generated in the detection pattern 80 of the FG detection pattern 75 at a position opposite to the rotation magnet 78, and is input to the hysteresis amplifier 76. The equation amplifier 76 performs waveform conversion amplification on the input sinusoidal speed pulse voltage and inputs the waveform to the microcomputer 77 as a square wave pulse signal.

Therefore, the microcomputer 77 compares and judges the input speed pulse signal (720 pulses per second in the normal case) to stably control the current drum motor 72 according to the set mode.

In such a conventional head drum motor, the FG generator forms a complex detection pattern 80 on the fixed printed board 79. Since the rotating magnet 78 must be formed with a certain gap (GAP) facing the detection pattern, the manufacturing cost increases accordingly, and the rotating magnet 78 is placed on the rotation circumference of the rotor 73 by N, The problem is that the FG generator becomes considerably complicated by multiple division magnetization with the S pole.

The present invention forms an ideal magnet at a fixed interval on the rotating magnet of the rotor in order to solve the above problems, and by using the zero crossing of the spike and the counter-electromotive force generated by the abnormal magnetization, such as the counter electromotive force of the three-phase coil, SUMMARY OF THE INVENTION An object of the present invention is to provide a frequency generator generator and method for a V-Cal head drum motor which can obtain FG having different on and off periods.

In order to achieve the above object, the present invention is a V-head head drum which generates FG by a three-phase coil wound around a core of a state and generating a counter electromotive force when a driving signal is applied, and a detection pattern formed on a rotating magnet of a rotor and a fixed printer substrate. In the FG generation method of the motor, an abnormal magnetizer magnet is formed on the rotary magnet at a predetermined interval, and the counter electromotive force generated from the three-phase coil during the rotation magnet rotation is divided into appropriate sections, and in the divided section, The on-off cycle is different from the zero-crossing of the spike waveform generated by the counter electromotive force.

In addition, the present invention is to form an ideal magnet magnet in the rotation magnet at regular intervals, and the V-Cal head drum motor to generate an FG of different on-off period from the zero crossing of the spike waveform and the counter electromotive force generated by the abnormal magnet A frequency generator generating apparatus comprising: a zero crossing detection circuit connected to a three-phase coil to detect a zero crossing point of reverse electromotive force generated from the coil, and an abnormal magnetizer connected to the three-phase coil to the back electromotive force generated from the coil. An abnormal magnetizer waveform detection circuit for detecting the generated spike waveform and a signal output from the zero crossing detection circuit and the abnormal magnetizer waveform detection circuit are combined to generate an FG generator.

1 is a configuration diagram of a frequency generator of a head drum motor of a conventional V-Cal.

2 is a counter electromotive force waveform diagram of a coil according to the present invention;

3 is a waveform diagram of a frequency generator (FG) according to the present invention.

4 is a frequency generator (FG) detection circuit in accordance with the present invention.

* Explanation of symbols for main parts of the drawings

11: Abnormal magnetization waveform detection circuit 12: Zero crossing detection circuit

13: FG generator

71: head drum 72: drum motor

73: rotor 74: stator

75: FG pattern 76: hysteresis amplifier

77: micom 78: rotating magnet

79: fixed printed circuit board 80: FG detection pattern

81: PG sensor 82: PG detector

Hereinafter, described in detail by the accompanying drawings as follows.

Figure 2 is a waveform diagram of the back electromotive force generated from the three-phase coil and the ideal magnet magnet of the drum motor according to the present invention, Figure 3 is a different FG on and off cycle generated by FIG.

4 is a FG detection circuit diagram according to the present invention, a zero crossing detection circuit 12 connected to a three-phase coil to detect a zero crossing point of back EMF generated from the coil, and generated from the coil connected to a three-phase coil. The combination of the signals output from the zero crossing detection circuit 12 and the abnormal magnetization waveform detection circuit 11 with the abnormal magnetization waveform detection circuit 11 for detecting the spike waveform generated by the abnormal magnetization magnet in response to the counter electromotive force. It consists of a FG generator 13 to generate.

According to the present invention, the driving signal is applied to the three-phase coil wound around the core 83 as shown in FIG. 1 and the rotor 73 rotates. The same sinusoidal counter electromotive force is generated, and when the half period (180 DEG) of the counter electromotive force is divided into three sections, a spike (SPIKE) is generated by the magnetization of the magnetized magnets magnetized in the rotating magnet 78.

In this case, if only zero crossing of U, V, and W phases is used, three FGs with the same on / off cycle can be made per cycle (360 °) .However, if the spike waveform is used by zero magnetizer and the zero crossing is used simultaneously, FGs having different on and off periods having an on / off period of 3: 1 can be obtained.

That is, if the half-cycle of U is divided into three sections, sections ② and ③ are the same area, and ① section and section ④ are the same area as section ② or section ③ (② = ③ = ① + ④). Here, if the section ② starts from the spike, ③ section is one FG period, the reverse electromotive force of V in the middle of section ③ is zero crossing, so that the FG with on / off period of 3: 1 can be obtained.

Similarly, in the range of 120 ° ~ 240 °, the reverse phase electromotive force of V phase shows two spikes in the positive state, and the reverse phase electromotive force of W phase causes zero crossing at 240 °, so the on / off period is 3: 1 You can get FG

Referring to this process by the frequency generator (FG) detection circuit diagram according to the present invention shown in Figure 4, first, a sinusoidal counter electromotive force such as U, V, W as shown in Figure 2 is generated from the three-phase coil, Spikes are generated by the abnormal magnetization magnet magnetized to the rotating magnet 78 at the counter electromotive force.

The counter electromotive force including the sine wave-shaped spike waveform is simultaneously applied to the abnormal magnetization waveform detection circuit 11 and the zero crossing detection circuit 12 to detect spikes and zero crossings of the abnormal magnetization waveform and transmit them to the FG generator 13, respectively. By combining the two input signals to output the FG as shown in FIG.

That is, the FG generator 13 outputs a high level signal when zero crossing of the back electromotive force of the three-phase coil is detected from the zero crossing detection circuit 12, and spikes are detected by the abnormal magnetization waveform detection circuit 11. In this case, by outputting a low signal, an FG having an on / off period of 3: 1 can be obtained as shown in FIG.

As described above, in the present invention, the abnormal magnetization is formed on the rotating magnet of the rotor at regular intervals, and the abnormal magnetization detects the spikes and zero crossings generated by the reverse electromotive force, respectively, like the counter electromotive force of the three-phase coil. By obtaining FG with different on and off periods, the speed control of the drum motor can be adjusted in various ways.

Claims (2)

In the frequency generator generating method of the BC head drum motor wound around the core of the state to generate the FG by the three-phase coil generating a counter electromotive force when applying the drive signal, and the detection pattern formed on the rotating magnet of the rotor and the fixed printer substrate, The magnets are formed in the magnets in the rotating magnets at regular intervals, and the reverse electromotive force generated from the three-phase coils during the rotation of the rotating magnets is divided into appropriate sections, and in this divided section, zero of the spike waveform and the counter electromotive force generated by the abnormal magnets are separated. A method for generating a frequency generator (FG) of a BC-AL head drum motor, characterized by generating FGs having different on and off periods from crossing. In the frequency generator generator of V-CAL head drum motor, which forms an abnormal magnet in the rotating magnet at regular intervals and generates FGs with different on / off periods from zero crossing of spike waveform and counter electromotive force generated by the abnormal magnet. A zero crossing detection circuit 12 connected to a three-phase coil to detect a zero crossing point of the counter electromotive force generated from the coil, and a magnetism of a magnetizer that is connected to the three-phase coil to the back electromotive force generated from the coil. The FG generator 13 generates an FG by combining an abnormal magnetization waveform detection circuit 11 for detecting a spike waveform and a signal output from the zero crossing detection circuit 12 and the abnormal magnetization waveform detection circuit 11. Frequency generator (FG) generating device of the BC-Cal head drum motor.