JPS60211659A - Rotating phase detector of cylinder motor for vtr - Google Patents

Abstract

PURPOSE:To control a cylinder motor for VTR, by preparing the switching pulse of a rotary head by dividing in frequency the detected output of a detecting means by using a signal produced in accordance with the difference between a detected output influenced by the magnetization of a magnetic pole and that influenced by a specific non-magnetized magnetic pole as a reference. CONSTITUTION:When a driving current is supplied to a driving coil 6, driving force is produced across the coil 6 and multi-pole magnet 4 and a rotor section rotates with a rotary shaft 1 at the center. A Hall element 10 detects the change in a magnetic flux caused by the rotation of the magnet 4 and also changes in magnetic fluxes caused by the rotation of small circular magnetized parts 4a, 4b, and 4c. By using a signal produced in accordance with the difference between the output of a detecting means influenced by a demagnetized magnetic pole and the output of the detecting means influenced by a specific magnetic pole which has the same polarity as the magnetic pole has but no magnetized part as a reference, the output detected by the detecting means is divided in frequency and the divided one is used as the switching pulse of a rotary head. Therefore, a Hall element to be used for detecting the change in a magnetic flux caused by a PG magnet at the time of rotation of a motor can be omitted and, as a result, the motor can be miniaturized and cost of the motor can be reduced.

Description

[Detailed description of the invention]

The present invention relates to a rotational phase detection device for a cylinder motor of a VTR having a servo function. $J fall → Noho 4i! Cylinder motor directly connected to rotating tram in home VTR In this function, we use "speed surf" to keep the rotation speed constant, and to change the rotation phase of the tram in the vertical direction of the video signal.
! There is a U-phase Surho J that is controlled by 11 signals. In these surf systems, -1- detects the rotation status of the rotary head tram and switches the plurality of rotary heads installed on the rotary head tram. 2) A magnetic flux change is arranged in the IJ motor section of the cylinder motor, and a detection means is arranged in the stator section, and the change in the magnetic flux produced by the rotation of the cylinder motor is detected by the above detection means. Conventionally, the rotational phase detection device shown in FIG. 2 and 3 are a plan view of the stator section as seen from the rotor section side, and a plan view of the rotor section as seen from the stator section side. In each of the above figures, 1 indicates the rotation axis of the motor. , 2 is a collar fixed to the rotating I/+lI, 3 is a yoke attached to the collar 2, and 4 is a driving multi-pole magnet placed on the yoke 3 and divided into 8 poles and magnetized. , 5 is a PG magnet arranged at the end of the yoke 3, and the rotor section is constituted by the rotation axis 1°, the collar 2. the yoke 3. the drive m, the multi-polar magnet 4, and the PG magnet 5. 6 is the drive coil for driving the motor, 7 is the lower l/ram, 8
9 is a printed circuit board on which the driving coil 6 is mounted and fixed to the lower tram 7; 9 is a ball element for detecting PG installed in a position facing the PG magnet 5; 6. Printed circuit board 8 and ball element 9
The stator section is composed of: Further, in FIG. 2, reference numeral 10 denotes a Hall element disposed inside the driving coil 6 on the printed circuit board 8, which detects the rotational phase of the driving multipolar McNut 4. Incidentally, the angle P may be any value as long as it is within the range of the angle at which one specific magnetic pole of the machinette 4 is crimped. Furthermore, in each figure, the same parts are designated by the same reference numerals. In the above-described structure, when a drive current is supplied to the drive coil 6, a drive force is generated between the drive coil 6 and the drive multi-pole magnet 4. Rotate around 1. At this time,” 2nd P.
The G-machine I' 5 also rotates together with the 1-coat portion, and the Hall element 9 detects changes in magnetic flux caused by this rotation, and outputs 1-C P G pulse. Figure 4 shows how the rotational phase of the cylinder motor is detected and frequency-divided based on the PG pulse, and a switching pulse for switching between the two rotary heads provided in the cylinder motor is obtained. and FIG. 5 will be explained. Incidentally, FIG. 4 is a block diagram for generating the -1- switching pulse, and FIG. 5 is a time chart thereof. Fourth
In the figure, 11a and llb are terminals to which the output of the Hall element 10 is supplied, 12 is an amplifier that amplifies the output (No. 8) from the terminals 11a and llb, and 13a and 13b are the
Terminal 14 is the terminal 13a, 1 to which the G pulse is supplied.
The amplifiers 15 and 1G that amplify the signals from 31) are flip-flops, but their outputs Q and data input are directly connected, so they are so-called binary flip-flops that are inverted every time a clock pulse is applied. It is a prop. 17 is an i-stable multivibrator operated by the output of the flip-prop 15;
The width of the output pulse is determined by the time constant of the resistor, capacitor, etc. connected to the monostable multivibrator 17. 18 is an inverter that inverts the output of the monostable multivibrator 17. The set terminals of the flip-flops 15 and 16 are grounded, and the output of the amplifier 14 is supplied to the reset terminal. In addition, the above flip flip tip 15
The output of the amplifier 12 is supplied to the clock terminal of
The output of the inverter 18 is supplied to the clock terminal of the flip-flop 16. In the above block, L blip-flop 1
The amplified output of the ball element 10 (jl) as shown in FIG. 5(a) is supplied to the clock terminal of 5, and the amplified output (jl) as shown in FIG. 5(1) is supplied to the reset terminal. TaP
When the G pulse is supplied, the signal shown in (a) of Fig. 5 rises and is inverted, and the signal shown in (1)) of Fig. 5 is present. 5 indicates that the level is determined to be low. A signal is output. (It is shown in (C) of FIG. 5.) The above-mentioned monoan 'jU multi-high inflator 17 generates a signal of a certain pulse width ( Fifth
Figure (d) ζ is not shown. ) and sends it to the inverter 18 at the next stage. , salary J I). 1 the inverter 18
Then, the signal from the monostable multi-high converter 17 is inverted to generate a signal as shown in FIG. do. ” - Connect the clock terminal and reset terminal of flip flip 1'1G to (e) and (L) in Figure 5.
+) When a signal as shown in IU is fed at 1%, the signal shown in (e) of Fig. 5 rises and is inverted, and the level where the signal shown in (b) of Fig. 5 is present is The number 1 determined to be low is output. (It is shown in (f) of Figure 5.) As is clear from comparing the rise and fall of the signal shown in (f) of Figure 5 with that of (a) of Figure 5, there are 8 poles. Since it appears every time the divided "2" driving multi-pole muck 7 4 makes a half turn, this pulse can be used as a switching pulse for switching the "2" rotating head. In addition, by adjusting the resistor connected to the monostable multi-height generator 17 and the time constant of Contin 4No,
It is possible to correct the mechanical mounting TJ error of the driving multi-polar macnet 5. However, in the conventional system described above, the PG Macnet 5 is fixed to the outer periphery of the rotor as shown in FIG.
Since the heads may exist near the rotor, the magnetic flux from the PG McNet 5 may be absorbed into these heads, causing noise components that disturb the audio signal or disturb the tram's → route. Atsunoko's fault. In addition, the ball element 9 for pulse detection is separately taken from the PG Mcnet 5 and PC-2 (:J' GJ), which increases the number of parts, increases cost, and reduces workability.
there was. The present invention has been made in order to eliminate the drawbacks of the conventional ones mentioned above, and it uses the same polarity to apply magnetization to a driving multi-pole mucket that functions similarly to the conventional F'G mucket. By applying this to all magnetic poles except for the 1.11° constant magnetic pole, the structure is simple and does not adversely affect the audio head and control unit. Our objective is to provide a rotational phase detection device for R cylinder motors. An embodiment of the present invention will be described below with reference to the drawings. 6th
The figure is a sectional view of the cylinder Tanabata including the rotational phase detection device, and FIGS. 7 and 8 are

[They are a plan view of the stator section seen from the coater section and a plan view of the rotor section seen from the stator section. In each figure, the same parts as in the conventional example shown in FIG. 1 etc. are designated by the same reference numerals. In each of the above figures, the rotor portion includes a rotating shaft 1 of the motor, a collar 2 fixed to the rotating shaft 1, a yoke 3 attached to the collar 2,
It is composed of a driving multi-pole magnet 4 placed on the yoke 3 and divided into 8 poles, and the iron is
There is no PG McNet that was available in the past. In addition, the stator part includes a drive coil 6 for driving the motor, a lower tram 7,
It is composed of a printed circuit board 8 on which the driving coil 6 is placed and fixed to the lower ram 7, but here there is no ball element for PG detection, which was found in the conventional one. Further, in FIG. 7, reference numeral 10 denotes a Hall element provided in the driving coil 6 on the printed circuit board 8, which detects the rotational phase of the driving multipolar magnet 4. Also, the 8th
As shown in the figure, in the above embodiment, out of the 8 poles provided in the driving multipolar magnet 11, all but one of the 4 magnetic poles having the same polarity is carved. Small circular magnetized magnets 4a, 4i] located near the center of the magnetic pole and facing the drive ball element 1 by λ·] and exhibiting a polarity opposite to that of the magnetic pole. 4c was applied. The reason why the magnetizations 4a, 4b, and 4C are made into small circles as described above is to avoid adversely affecting the drive and steady rotation of the motor. Since the area occupied by the magnet is very small compared to the area of the magnetic pole, the negative effect can be almost ignored. In the above-mentioned configuration, ``2, drive 21, 6
When a driving current is supplied to the rotor, a driving force is generated between the driving coil 6 and the driving multi-polar magnet 4, and the rotor rotates around the rotating shaft 1. At this time, the driving ball element 10 is connected to the magnetic flux change caused by the rotation ζ of the driving multi-pole magnet 4 and the small circular magnetization 4.
Changes in magnetic flux caused by the rotations of a, 4.1) and 4c are detected and a waveform as shown in FIG. 9 is output. Here, the part where the output waveform shown by the dotted line in Fig. 9 has a crushed shape is due to the magnetic flux due to the small circular magnetization 4 rJ +4 b, ric shown in Fig. 8 for driving. This is caused by canceling -gl (of the magnetic flux of Of the 8 magnetic poles provided in the drive multi-pole magnet 4 and having the same bending properties, the magnetic poles other than the small circular magnetized magnetic poles 4a, 4b, and 4c are The waveform may be due to changes in magnetic flux, but it looks like it jumps out to the positive side. Here, when the reference operating voltage (slice level) of the amplifier to which the output waveform of the Hall element 10 is supplied is raised as shown in FIG. The pulse generated by the protrusion or the drive multiplier described above (chimacnet il or 1 rotation per rotation)
Output times. Next, using this to detect the rotational phase of the cylindrical motor and obtain a switching pulse for switching one rotary head disposed on the cylindrical motor is shown in Figs. 10 and 11. explain. Furthermore, the first
Figure 0 is a block diagram for generating the switching pulse, and Figure 1 is the time chart.
In the figure, 10 is a ball element as described above,
In this case, as shown in FIG.
]- may be removed. Reference numeral 19 is an amplifier that differentially amplifies the output of the ball probe 1 (J), and its operating voltage is approximately halfway between the power supply voltage 1B and GNI.
By increasing the amplification factor, a waveform as shown in FIG. 11(a) can be obtained. Reference numeral 20 denotes an amplifier to which the output of the Hall element 10 is supplied, and when viewed from the output side, the quasi-operating voltage is <Va (higher than the standard operating voltage of the amplifier 19) as shown in Figure 1. Therefore, as shown in FIG. 11(b), a signal is obtained that is outputted once as a pulse during one rotation of the driving multi-pole mcnet 4. 21 and 22 are flip-flops. 1 Tip 1. Since their output Q and data output are directly connected, they are so-called binary flip-flops that invert each time a clock pulse is applied. 2 and 3 are the flip-flops mentioned above. It is a monostable multivibrator operated by the output of 21, and the width of the output pulse is determined by the time constant of the resistor and capacitor connected to the monostable multivibrator 23.24 is a monostable multivibrator operated by the output of 21. This is an inverter that inverts the output of the high inflator 23.The set terminals of the flip-flops 21 and 22 are grounded, and the reset terminals are supplied with the output of the amplifier 20 in item 1. Flip
The clock terminal of the flip-flop 21 is supplied with the output of the amplifier 19, and the clock terminal of the flip-flop 22 is supplied with the output of the inverter 24. In the flip-flop 1 cock described above, the output of the amplifier 19 shown in FIG. (1) Amplifier 2 (
] is supplied, the signal shown in FIG. 11(a) is inverted at the rising edge and the level is determined to be low where the signal shown in FIG. 11(l) is present. Output. 1 (C) ζ in Figure 11 is not shown. ) The monostable multivibrator 23 is the same as (C) in FIG. 11 above.
) is the same as the falling edge of the signal shown in Itrs L/ta,
A certain Hals convergence signal ((d)t of 111Δ is not shown)
Inverter 24 of the next stage
supply to. The inverter 24 inverts the signal from the monostable Maruna high inflator 23 and converts it into the signal shown in FIG.
) generates a signal 1c as shown in 'J-' and connects it to the clock terminal of the flip-flop 22 in the next stage. to be provided. (e) and (1) in FIG.
When a signal like that shown in FIG. 11 is supplied, the signal shown in (b) in FIG.
Where there is a signal not shown in , a signal determined to be J\l or [l- is output. (This is shown in (f) of Fig. 11.) As is clear from the comparison with (a) of Fig. 11, the rise and fall of the signal shown in ([>) of this Fig. 11 is very low. Since it appears every time the driving multi-pole mucknet 1, which is divided into poles, makes a half rotation, this can be used as a switching pulse for switching the rotating head. By adjusting the time constant of the resistor and capacitor 41- connected to the resistor 23, it is possible to correct the mechanical centering error of the driving multi-pole mcnet ↓. Magnetic 4 a + 41) l 4
c may be made into a small circle or may be linearly magnetized in the radial direction, and the same effect as in the above embodiment can be obtained. 1, the present invention provides a driving multi-pole machining element 4 which is fixed to a rotating shaft l and has been subjected to first magnetization so as to be divided in the circumferential direction, and a driving multi-pole machining element 4 which is fixed to a rotating shaft l and which is divided in the circumferential direction. A specific one of the magnetic poles of the same polarity (all magnetic poles except ÷) -
Magnetized 4a, 4 with no polarity opposite to the polarity of the magnetic pole applied to
．． The rotational phase in a cylinder motor for a VTR is equipped with second magnetization such as b, 4c, etc., and detection means such as a Hall element 10 for detecting the rotational phase angle of the driving multi-pole macnet 4. In the detection device, the output of the detection means due to the influence of the second magnetized magnetic pole and the specific one magnetic pole that is the same polarity as the second magnetized magnetic pole. The switching pulse of the rotating head is obtained by dividing the output detected by the above detecting means based on the signal generated by the output difference between the output of the above detecting means due to the influence of (1) It is possible to omit the conventionally required PG McNet and the ball element that detects the change in magnetic flux caused by the PG McNet when the motor rotates, so it is effective in downsizing and cost reduction of Tanabata. (2) Since the ball element can be omitted, the current consumption can be reduced compared to the conventional device using this element. (3) Since the PG mucknet can be omitted, the above The magnetic flux from the F'G magnet 5 enters the audio head and the control 1 full head and disturbs the audio No. 18 as a noise component and the servo of the drum. This eliminates the drawback that the S/N ratio of each of the above heads is improved. .

[Brief explanation of drawings]

1, 2, and 3 are cross-sectional views of a conventional cylinder motor, a plan view of the stator section seen from the rotor section side, and a plan view of the rotor section seen from the stator section side, and FIG. 4 is a 1
．． Figure 514 does not show the rotational phase detection device installed in the cylinder motor for VTR.
・Figures 6, 7, and 8 are a cross-sectional view of the cylinder motor according to the present invention, a plan view of the stator section as seen from the rotor section side, and a plan view of the rotor section as seen from the stator section side. , FIG. 9 is a waveform diagram showing the output of the driving Hall element shown in FIG. 7, and FIG. 10 is a waveform diagram showing an example of the present invention.
FIG. 11 is a block diagram of the rotational phase detection device for the R cylinder motor LL, and is a time chart 1 for explaining the operation of an embodiment of the present invention. l... Rotating shaft, 4... Multipolar magnet for drive, 4a
, 4+), 4C... Magnetized, 10--- Hall element. Patent applicant Akai Electric Co., Ltd. Figures 1 and 2. Figure 3 Figure 5 Figure 6 Figure 1 I ryJ Procedural amendment (龜ふ) Commissioner of the Patent Office Mr. 1. Indication of the case "Y'r1M Fu-Kusukofu 7-t1. Party 3. Telephone number of the person making the amendment (Tokyo) )742-5111 (rotary position detection device for motor with net) <2> Regarding the 'J-Application', the scope of claims in the specification will be amended as in the attached sheet. (3) In the same specification, lines 3 to 6 of page 2 are amended to read J: in the following sentence. ``This invention relates to a detection position for detecting the rotational position of a rotor in a motor having a drive magnet, and is suitable for a cylinder motor of a home VTR that detects the rotational phase and controls the rotational phase of the motor. In general, it is directly connected to the rotating head drum of a home VTR.'' (4) In the same specification, from line 17 on page 2 to line 6 of the same page, it is stated that ``the thing to be detected is known. (5) In the same specification, the last line of the second page states "rotational phase detection".
Correct the statement to "rotational position detection". (6), "Rotational phase" in the first line of page 3 in the specification.
Correct the statement to "rotation position". (7), same, in the specification, page 8, line 9 to page 1 of the same page.
Correct the line 1 as shown below. ``This invention eliminates the drawbacks of the above-mentioned 1.
At some point, one particular magnetic pole was configured so that the magnetic flux applied to the means for detecting magnetic flux such as a pole element was stronger than other magnetic poles of the same polarity, so PG mag? , and no need for the V T
To provide a rotational position detecting device for a motor having a driving magnet capable of reducing the influence of magnetic flux straying into the R's head and the control's head. It is an object. An embodiment of the present invention will be described below with reference to the drawings. In this embodiment, as described above, "a specific negative magnetic pole among the magnetic poles of the same polarity in the driving multi-pole mucket is compared with other magnetic poles of the same polarity, and is applied to a means for detecting magnetic flux such as a Hall element. In order to increase the magnetic flux generated by the magnetic flux, a small face (α
The magnetization of 1i'f shi, due to the magnetization of this small area, "-
This weakens the applied magnetic flux. Figure 6 shows the cylinder motor including the rotational phase detection device (8).
, same, in the specification, page 11, line 14 to page 15
The line t5 is corrected to read ``Outputted once.'' as ``Outputted once, and the rotational position of the rotor section is detected.'' (9), Ibid., Meiki ■ Shōchu, page 15, 10i [Correct the 6th line of pages 1 to 16 to read as in European language. "In addition, in the above practical example, this invention is
Although the application to a TR has been described, it is clear that the present invention can also be applied to other rotational position detection or motors having a necessary drive magnet. As described above, the present invention provides a motor having a rotor portion (driving magnet) which is magnetized for driving with different polarities at equal intervals and alternately in the direction of rotation, in which the rotor portion is rotatable. A means such as a Hall element for detecting the magnetic flux from the magnetic poles of the magnetized surface is disposed in the stator section which is supported by the rotor section in the vicinity of the magnetized surface of the rotor section, and detects the same polarity on the magnetized surface. Among the plurality of magnetic poles, the identified single magnetic pole is such that the magnetic flux applied to the means for detecting the magnetic flux is substantially stronger than other magnetic poles of the same single magnetic pole.
Since each of the above magnetic poles is configured, the following effects can be obtained. (10) Liang, same, specification, page 16, line 16 to page 1
The seventh line says, "Magnetic flux jumps into the audio head and control head." The above magnetic flux or jump in the head should be corrected. (l/) Ka, same, in the specification, page 16, line 18, "disturbing defect"
I corrected it with a certain ``fault such as disturbing things''. A stator part that rotatably supports the rotor part in a motor having a rotor part in which drive magnetization of different polarities is alternately and equally spaced along the rotational direction. is provided with means for detecting magnetic flux from the magnetic poles of the magnetized surface in the vicinity of the magnetized surface of the rotor section, and
The identified single magnetic pole among the plurality of magnetic poles of the same polarity is connected to each of the magnetic poles so that the magnetic flux applied to the means for detecting the magnetic flux is substantially stronger than the magnetic poles of the same polarity. A rotational position detection device for a rotor connected to a motor that uses a drive magnet, characterized by comprising:

Claims (1)

[Claims] Excluding a driving multi-pole magnet that has been subjected to a first magnetization such that the rotating shaft is hardened and divided in the direction of a circle IJ+, and one specific magnetic pole among the magnetic poles of the same polarity in the driving multi-pole magnet. A second magnetization having a polarity opposite to that of the magnetic poles applied on all the magnetic poles and a detection means for detecting the rotational phase angle of the driving multi-pole macnet are set by l,ijl,V] '
In the rotational phase detection device in the R cylinder motor, the output of the detection means due to the influence of the second magnetized magnetic pole and the 20th magnetic pole having the same polarity as the second magnetic pole and not magnetized. The switching pulse of the rotary head is obtained by frequency-dividing the output detected by the detecting means based on the signal generated by the output difference between the output of the detecting means and the output of the detecting means due to the influence of one specific magnetic pole. A rotational phase detection device for a cylinder motor for a VTR.