JP2000139098A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stepping motor of an electronic apparatus wherein con sumption power is little, durability is excellent and stable start up and high speed rotation are enabled. SOLUTION: In an electronic apparatus having a stepping motor, this stepping motor is a stepping motor having a two-pole flat stator. A driving pulse of the stepping motor comprises a starting pulse composed of a combinational pulse C and a initiate pulse E and a following drive pulse H. The stepping motor is rotated at a high speed by the drive pulse H in synchronism with the time when a counter-electromotive force developed in a counter-electromotive force detecting coil 306 crosses the zero level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor incorporated in an electronic apparatus, and more particularly to a motor having a two-pole stator, a rotor and a coil.

[0002]

2. Description of the Related Art A technique for rotating a motor built in an electronic device at a high speed is generally used. In particular, a motor using a flat stator is used for a timepiece or the like. is there. In order to rotate such a motor at high speed, some contrivance is required. In the present application, a motor used for a vibration alarm incorporated in a wristwatch as an embodiment will be described as an example.

A conventional wristwatch with a vibration alarm incorporates an ultrasonic motor as a source of vibration, and transmits vibration of an eccentric rotor of the ultrasonic motor to a wrist via a watch case to notify the wrist as a vibration alarm. Kaihei 2-6291
No. 6,086,045. On the other hand, a motor using a flat stator mainly performs low-speed rotation as described above, and there is no example in which the motor is used for high-speed rotation.

[0004]

However, the above-mentioned ultrasonic motor has a problem due to its fundamental structure. First, there is the problem of wear resistance. The stator is a piezoelectric element, which transmits vibration of the piezoelectric element, a vibrating body bonded to the piezoelectric element, and further increases the amplitude of vibration of the vibrating body.
The eccentric rotor is constituted by a comb-shaped portion attached to the vibrating body. The eccentric rotor is pressed against the comb-shaped portion by a spring, and rotates when the piezoelectric element vibrates. Since the eccentric rotor is pressed against the comb teeth by a spring, there arises a problem of wear resistance of the contact portion between the eccentric rotor and the comb teeth.

In addition, since the amplitude of the vibration of the piezoelectric element is small, there is a problem that the component accuracy and the assembly accuracy of the piezoelectric element, the vibrator, the comb teeth, and the eccentric rotor must be strict. In addition, power consumption is increased due to poor efficiency. AQ (Analog Quartz) with a vibration alarm using an ultrasonic motor at the 1991 Autumn Meeting of the Watch Society of Japan
In the research presentation on the theme of development of the eccentric rotor, 60
It is reported that the driving current becomes 60 mA when rotating at 00 rpm.

According to the present invention, there is provided a motor capable of rotating at a high speed and having a durable rotation of a rotor, easy assembling, low power consumption, stable start-up, and without using an ultrasonic motor as described above. An object is to provide an electronic device having a built-in step motor.

[0007]

In order to achieve the above object, the present invention has the following arrangement. In an electronic apparatus having a motor including a stator having a rotor having a permanent magnet and a drive coil magnetically coupled to the stator, a drive signal generating means for outputting a drive signal for driving the motor; A driving circuit for supplying a driving current to the driving coil based on a driving signal from a signal generating unit; the stator for transmitting a magnetomotive force generated in the driving coil to the rotor; and a counter electromotive force generated by rotation of the rotor. A back electromotive voltage detection coil for detecting a voltage, and magnetic pole position detection means for detecting a magnetic pole position of the rotating rotor with respect to the stator based on a back electromotive voltage generated in the back electromotive voltage detection coil; The signal generator controls output timing of the drive signal based on a detection signal from the magnetic pole position detector. To.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, taking an example of a wristwatch with a built-in vibration motor having a built-in step motor in an electronic device having a built-in step motor.

FIG. 7 is a plan view showing a wristwatch with a built-in vibration alarm according to the present invention. Reference numeral 701 denotes a watch case; 704, a stepping motor for vibration alarm including the eccentric weight 302 attached to the rotating shaft of the rotor 303 and a driving coil 705; 702, a wristwatch module having a driving circuit for the stepping motor; 703, a stepping motor It is a driving battery. The step motor 704 is shown in FIG.
As shown in the plan view of the stator and the rotor of FIG.
This is a step motor having a pole-type stator 304 and a two-pole rotor permanent magnet 308.

Here, as long as the function described below can be realized, the stator hole 310 has two slits 309 shown in FIG.
However, the present invention is not limited to a structure in which a semicircle formed by cutting the stator 304 in the direction connecting 09 (vertical direction) is shifted in the vertical direction.

The step motor 704 can be disposed between the watch case 701 and the watch module 702 without generating an unused space. Further, the step motor 704 is characterized in that it can be arranged without being stacked on the step motor driving battery 703. When the stepping motor 704 is driven by a driving pulse having a constant period shown in FIG. 8, the number of rotations per minute is 10
Since the rotation speed is about 00 rpm, the vibration of the step motor can be transmitted to the arm and notified as a vibration alarm.

However, in order to produce a centrifugal force of about 0.098 N which acts on the eccentric weight necessary for transmitting vibration to the arm more reliably, the number of revolutions per minute of the rotor is set to 3000 rpm or more, and the arm is shaken. Even when acceleration is applied to the step motor 704, the rotation is stabilized and the reliability as a vibration alarm is improved.

First, a description will be given of a high-speed rotation driving method of the rotor according to the present invention for increasing the number of revolutions per minute of the rotor to about 3000 rpm or more in the separation type coil. FIG.
FIG. 3A is a plan view of a stepping motor for driving a vibration alarm in a separation type coil, and FIG.
FIG. 3 is a cross-sectional view taken along the line C-C ′, and FIG.
(C), and the step motor 301 has an eccentric weight 302
Are provided with a rotor 303, a stator 304, a drive coil 305, and a back electromotive voltage detection coil 306 provided with a. One back electromotive voltage detection coil 306 is separated from the drive coil 305, and is wound around the inner periphery of the drive coil 305 with respect to the coil core 307 as shown in FIG. I have.

The back electromotive voltage generated in the back electromotive voltage detection coil will be described.

The back electromotive voltage V generated in the back electromotive voltage detection coil
a Since the current i _a flowing through the counter electromotive voltage detection coil can be zero, due to the DC resistance Ra of the counter electromotive voltage detection coil,
Ignoring the-counter electromotive voltage -La (di _a / dt) due to time variation of the voltage drop Ra-i _a and the current i _a (La, the self-inductance of the counter electromotive voltage detection coil 306), determined by an equation 1 Can be

[0016]

(Equation 1)

In equation (1), −M · (di / dt) is the mutual inductance M between the back electromotive voltage detection coil 306 and the drive coil 305 (the mutual inductance M is the respective inductance of the drive coil 305 and the back electromotive voltage detection coil 306). Assuming that the number of turns is n _a0 and n _a , M = k · n _a0 · n _a / Rm.

Here, k is a proportional constant, and Rm is the inverse of the sign of the product of the time change of the drive current i (hereinafter also referred to as the current when the drive pulse is off) and Rm is the magnetic resistance of the magnetic circuit of the step motor. , The drive current i changes with time, and -Ka · sin (θ + θ _o ) · (dθ / d
t) is a mechanical coupling coefficient Ka with the step motor 301, s
in (θ + θ _o ) and the time change of the rotation angle θ of the rotor 303, that is, the sign of the product of the angular velocity is reversed.
3 is generated by rotation.

Θ _o is the initial angle of the rotor 303,
In the plan view of the stator and the rotor shown in (c), the angle is from the position of the magnetic pole N (S) of the rotor permanent magnet 308 of the rotor 303 of the rotor 303 stopped by the detent torque to a position substantially 90 degrees from the slit 309 of the stator 304.

Further, an output Vga of a differential amplifier, which will be described later,
Is obtained by the following equation (2).

[0021]

(Equation 2)

Vga in Equation 2 is the differential amplified output F of the differential amplifier 108 in the block diagram of the high-speed rotation drive circuit for the rotor of the step motor shown in FIG.
By detecting when Ka · sin (θ + θ _o ) · (dθ / dt) becomes zero, the magnetic pole N (S) of the rotor permanent magnet 308 of the rotor 303 stopped by the detent torque shown in FIG. Said rotor 30 from position
3, the rotation angle θ (−θ _o , −θ _o + π) can be detected. Here, Ga is the gain of the differential amplifier 108 (hereinafter also including the sign). Note that -Ga · M ·
Since (di / dt) can be ignored, it does not affect detection.

A block diagram of an embodiment of a high-speed rotation drive circuit for a rotor of a step motor having a separation type coil shown in FIG. 1 will be described. First, the driving coil 30 of FIG.
5 is separated from the back electromotive voltage detection coil 306, the drive coil 305 is connected to the drive circuit 110, and the back electromotive voltage detection coil 306 is connected to the differential amplifier 108.

FIG. 1 shows a vibration alarm set / reset circuit 105 for outputting a vibration alarm generating pulse A at a vibration alarm time, and a driving on / off generating circuit for outputting a driving on / off signal B when the vibration alarm generating pulse A is inputted. 106, a battery voltage detection circuit 111 that receives a battery voltage detection instruction signal D to detect a battery voltage and outputs a battery voltage rank signal I, a phase matching pulse C and a phase matching pulse that outputs the battery voltage detection instruction signal D The means 112 has a starting pulse generating means 113 for outputting a starting pulse E and a subsequent driving pulse generating signal J.

FIG. 1 shows a subsequent drive pulse generating means 114 for outputting a subsequent drive pulse H. The input of the battery voltage rank signal I causes acceleration to the extent that the respective battery voltages are generated by waving the arm. Is step motor 3
01, the stepping motor 301 can be started stably and the optimum pulse width can be stably rotated at a high speed. The matching pulse width, the starting pulse width, the subsequent driving pulse width, Corresponding to the pulse interval between the matching pulse and the starting pulse, a matching pulse width signal K, a starting pulse width signal L, a subsequent driving pulse width signal M,
The pulse width setting means 115 outputs the pulse interval signal N.

Further, a driving pulse generating microcomputer 109 having a pulse interval setting circuit 116 for outputting a starting pulse generating signal O, a driving coil 305 when a driving pulse composed of the phase matching pulse C, starting pulse E, and subsequent driving pulse H are inputted. The drive circuit 110 for supplying a drive current to the drive coil 305 for driving the step motor 301,
Back electromotive voltage detection coil 306 for detecting rotor generated back electromotive voltage generated by rotation of rotor 303
Having.

A differential amplifier 108 for differentially amplifying the back electromotive voltage Va generated in the back electromotive voltage detection coil 306 and outputting a differential amplified output F, and a differential amplifier which is an output of the differential amplifier 108 FIG. 1 is composed of a zero-cross comparator 107 which outputs a zero-cross comparator output G to the subsequent drive pulse generating means 114 in response to the input of the output F. The high-speed rotation drive circuit and the battery voltage detection circuit 1
Of course, 11 is connected to a battery (not shown) for supplying power.

FIG. 2 is an explanatory diagram for driving the rotor of the step motor having the separation type coil shown in FIG. 2 at a high speed. FIG. 1 shows the embodiment of the high speed rotation drive circuit for the rotor of the step motor having the separation type coil shown in FIG. Description will be given with reference to a block diagram. First, when the set vibration alarm time comes, the vibration alarm set / reset circuit 105 outputs the signal from FIG.
Is output, and the drive on / off generation circuit 106 outputs a drive on / off signal B shown in FIG.

The synchronizing pulse generating means 112 outputs a synchronizing pulse C shown in FIG. 2C to activate the rotor 303, and a driving current is supplied to the driving coil 305 by the driving circuit 110 to drive the rotor 303. At this time, it is not known whether or not the rotor permanent magnet 308 of the rotor 303 is stationary at a position where the rotor permanent magnet 308 can be activated by the synchronizing pulse C.

That is, if the polarity of the magnetic pole generated in the stator 304 excited by the matching pulse C is the same as the polarity of the magnetic pole of the rotor permanent magnet 308 of the rotor 303 facing the magnetic pole of the stator 304. The rotor 303 rotates, but if the polarities are different, the rotor 303 does not rotate.

However, by the synchronizing pulse C,
Subsequent drive pulses, that is, the polarity of the magnetic pole generated in the stator 304 excited by the starting pulse E and the subsequent drive pulse H is the same as the polarity of the magnetic pole of the rotor permanent magnet 308 of the rotor 303 that is opposed to the magnetic pole of the stator 304. Since the polarity is the same, the subsequent drive pulse can rotate the rotor 303.

[0032] Figure 2 the phase adjustment pulse generator 112 after t _o from the rise of the phase adjustment pulse C (d)
Is output to the battery voltage detection circuit 111. The battery voltage detection circuit 111 detects the battery voltage and outputs a battery voltage rank signal I to the pulse width setting means 115.

The pulse width setting means 115 starts the step motor 301 stably even when acceleration to the extent that the battery voltage is generated by, for example, shaking the arm is applied to the step motor 301, and stably operates at a high speed. The synchronizing pulse width, the starting pulse width, the subsequent driving pulse width, the synchronizing pulse width signal K and the starting pulse width signal L corresponding to the synchronizing pulse and the starting pulse interval set so as to be able to rotate. , The subsequent drive pulse width signal M and the pulse interval signal N are respectively matched with the pulse generation means 112, the starting pulse generation means 113, and the subsequent drive pulse generation means 11
4. Output to the pulse interval setting means 116.

The synchronizing pulse generating means 112 receives the synchronizing pulse width signal K from the battery voltage detecting circuit 1.
11 outputs a matching pulse C having a pulse width (tc) corresponding to the detected battery voltage to the drive circuit 110. The pulse interval setting means 116 calculates the phase matching pulse C
And a start pulse generation signal O formed from the pulse interval signal N to the start pulse generation means 113.

The starting pulse generating means 113 receives the starting pulse width signal L,
A starting pulse E having a pulse width (te) corresponding to the detected battery voltage and a falling tf of the starting pulse E, an auxiliary starting pulse 201 having a pulse width tg and assisting the driving of the step motor by the starting pulse E. (Below, unless otherwise specified, the starting pulse E includes the auxiliary starting pulse.)
Is output to the drive circuit 110 by the start pulse generation signal O after td from the fall of the phase matching pulse C.

The differential amplifier output F of the differential amplifier 108 connected to the back electromotive voltage detection coil 306 is shown in FIG.
Shown in The differential amplifier output F has a spike noise 202
(Hereinafter, unless otherwise noted, this refers to noise corresponding to the trailing edge of the subsequent drive pulse H). In response to the input of the differential amplifier output F, the zero-cross comparator 107 outputs a zero-cross comparator output G to the subsequent drive pulse generating means 114 as shown in FIG. A spike pulse 204 corresponding to the spike noise 202 is superimposed on the zero-cross comparator output G.

However, the subsequent drive pulse generating means 114
Has a function of digitally masking a spike pulse 204 corresponding to the spike noise 202 shown in FIG. 5, so that the subsequent drive pulse generation unit 114 outputs the subsequent drive pulse generation signal from the starting pulse generation unit 113. After the input, the zero cross 203 shown in FIG.
2H, the rising and falling times of the zero cross comparator output G shown in FIG. 2G are synchronized with the times excluding the rising and falling times of the spike pulse 204. As shown, the battery voltage detection circuit 111 corresponds to the battery voltage detected,
The matching pulse width (tc) and the starting pulse width (te)
A subsequent drive pulse H having a narrower pulse width (tah) is output.

The stepping motor 301 is constantly accelerated by the subsequent driving pulse H, and can rotate the rotor 303 at a high speed at a rotational speed balanced with the frictional resistance acting on the rotor 303. The magnetic pole position detecting means having the differential amplifier 108 and the zero cross comparator 107 connected to the back electromotive voltage detecting coil 306 is the same as that shown in FIG.
2 (g) corresponding to the differential amplifier output F shown in FIG. 2 (g) and the comparator output G shown in FIG. 2 (g), while the rotor 303 rotates at a high speed from the stop state (from time zero to the pulse width tg assist). It can be seen that the magnetic pole position of the rotor 303 during rotation (time until the vicinity of the starting pulse 201) can also be detected based on the back electromotive voltage generated in the back electromotive voltage detection coil 306.

Here, the following drive pulse generating means 11
No. 4 makes the pulse width (tah) of the subsequent drive pulse H narrow as the rotation speed of the stepping motor increases, and makes the pulse width (tah) optimal for the rotation speed of the stepping motor. In the present embodiment, the differential amplifier 108 shown in FIG. 4A does not have a low-pass filter, so that a low-pass filter including a resistor R1 and a capacitor C1 shown in FIG. ), The rotation angle θ corresponding to the rise and fall of the zero-cross comparator output G excluding the spike pulse 204 is substantially −θ _o. Or π-θ _o
become.

Compared to the case where there is a low-pass filter composed of R1C1, it is possible to sufficiently accelerate before applying a brake (rotation when θ = 0 to π / 2 or π to 3π / 2) against the rotation of the step motor rotor by the detent torque. And the number of rotations of the rotor can be increased.

A configuration diagram of a circuit for digitally masking spike pulses shown in FIG. 5 will be described with reference to a functional time chart of a circuit for digitally masking spike pulses shown in FIG. Since the starting pulse composed of the matching pulse and the starting pulse is output from the matching pulse generating means and the starting pulse generating means independently of the zero-cross comparator output G, FIG. 4 shows a subsequent drive pulse.

The spike pulse 204 may not be generated when the rotation speed of the step motor increases, and FIG. 6B shows the output G of the zero-cross comparator where the spike pulse 204 is generated and the spike pulse. The zero-cross comparator output G in which 204 has not occurred is shown.

FIG. 5 masks the inversion of the zero-cross comparator output G generated by the start pulse E with respect to the zero-cross comparator output G (here, the start pulse E is the start pulse E excluding the auxiliary start pulse).
Block 1, back edge 60 of spike pulse 204
Block 2 for masking 2, spike pulse 20
4 is a block 3 for masking the front edge 601 of FIG. 4 and corresponding to the zero-cross comparator output G in which the spike pulse 204 is not generated.

First, in block 1, the zero-cross comparator output G is input to a waveform shaping circuit which makes multiple rising and falling at the rising and falling of the pulse of the zero-cross comparator output G into a single rising and falling. By being shaped and ORed with the start pulse E, the inversion of the zero cross comparator output G occurring before the end of the start pulse E is avoided.

In block 2, first, the zero-cross comparator output G is passed through a delay circuit 501 to mask the back edge 602 of the spike pulse 204.
Outputs F3Q (d), F3 of flip-flops F3, F4 based on the inverted and non-inverted inputs of the output of the delay circuit 501
4Q (e), and then F3Q by AND, A1
(D) and the AND output of F4Q (e), A1 (f). Here, a beard pulse output M2Q (g) of the pulse generator M2 due to the rise of the subsequent drive pulse H (a).
As a result, the flip-flops F3 and F4 are reset.

In block 3, the outputs F1Q (j) and F2Q of the flip-flops F1 and F2 based on the inverted (c) and non-inverted (b) inputs of the output G of the zero cross comparator.
(K), and OR the F1Q (j) and F2Q (k)
The output Q2 (l) is output to generate a subsequent drive pulse H. Here, in order to mask the spike pulse 204, the output pulse M1Q (h) of M1 and the back edge 602 are generated by the falling edge of the subsequent drive pulse H (a) for masking the front edge 601. OR output Q1 of A1 (f) for masking
(I) resets the flip-flops F1 and F2.

Hereinafter, an embodiment using a tapped coil will be described. FIG. 11A is a plan view of a stepping motor for driving a vibration alarm in a coil with a tap, and FIG.
1B is a cross-sectional view taken along the line CC ′ of FIG. 11A. The plan view of the stator and the rotor is the same as that of FIG. 3C. The step motor 1101 has a rotor 303 provided with an eccentric weight 302. It comprises a stator 304 and a drive coil 1102. As shown in FIG.
Reference numeral 103 denotes a coil made up of the drive coil 1102 as a whole or a tap taken out from a part thereof.

The back electromotive voltage generated in the back electromotive voltage detection coil 1103 will be described. Counter electromotive voltage Vb generated in the counter electromotive voltage detection coil, the current flowing in the counter electromotive voltage detection coil as i _b, the following equation 3, including a voltage drop Rb · i _b by DC resistance Rb of the counter electromotive voltage detection coil It is required.

[0049]

(Equation 3)

In Equation 3, -Lb · (di _b / dt)
Is the equivalent self-inductance Lb of the back EMF detection coil 1103 (the number of turns of the back EMF detection coil 1103 is nb,
The number of turns of the coil portion that does not use the counter electromotive voltage detection coil 1103 of the drive coils as nb _0, the equivalent self-inductance Lb becomes _{^{(nb 2 + nb · nb 0}} ) / Rm. Here Rm is obtained by the sign of the product of the time change in the magnetic resistance and the driving current i _b of the magnetic circuit of the stepping motor in reverse, the drive current i _b is generated by time-varying.

-Kb · sin (θ + θ _o ) · (dθ / d
t) is a mechanical coupling coefficient Kb with the step motor 1101;
The sign of the product of sin (θ + θ _o ) and the time change of the rotation angle θ of the rotor 303, that is, the product of the angular velocity is reversed.
03 is generated by rotation. θ _o is rotor 3
At an initial angle of 03, in the plan view of the stator and the rotor shown in FIG. 3C, the position of the magnetic pole N (S) of the rotor permanent magnet 308 of the rotor 303 stopped by the detent torque is almost 90 degrees from the slit 309 of the stator 304. Is the angle up to the position.

Further, an output Vgb of a differential amplifier described later
Is obtained by the following equation (4).

[0053]

(Equation 4)

Vgb in Equation 4 is the differential amplifying power F of the differential amplifier 908 in the block diagram of the high-speed rotation drive circuit for the rotor of the step motor shown in FIG.
By detecting when b · sin (θ + θ _o ) · (dθ / dt) becomes zero, the magnetic pole N (S) of the rotor permanent magnet 308 of the rotor 303 stopped by the detent torque shown in FIG. The rotor 303 from position
Can be detected (−θ _o , −θ _o + π).

Here, Gb is the gain of the differential amplifier 908. Output Vgb of differential amplifier in tapped coil
Extent is compared to the output V of the adder in the cancellation coils to be described later, -gb · Lb · with time change in the drive current ib of the driving coil _{(di b / dt) -Rb ·} i b but enters, negligible belongs to.

The configuration of a block diagram of an embodiment of a high-speed rotation drive circuit for a rotor of a step motor having a tapped coil shown in FIG. 9 will be described. FIG. 9 is a block diagram of an embodiment of the high-speed rotation drive circuit of the rotor of the step motor shown in FIG. 1, a drive coil 305, a method of connecting the drive coil 305 and the drive circuit 110, the drive coil 305 and the differential amplifier 1
In the connection method 08 and the differential amplifier 108, the drive coil 1102 in FIG. 9 is connected to the drive circuit 110, and the back electromotive voltage detection coil 1103 is connected to the differential amplifier 108.
08. Hereinafter, since it is the same as FIG. 1, the description is omitted.

FIG. 10 is an explanatory diagram for driving the rotor of the step motor having the tapped coil shown in FIG. 10 at high speed, and FIG. 9 is a diagram showing the embodiment of the high speed rotation driving circuit of the rotor of the step motor having the tapped coil shown in FIG. This will be described with reference to a block diagram. In FIG. 10, (a) to (e) are the same as FIG. The differential amplifier 9 connected to the back electromotive voltage detection coil 1103
The output F of the differential amplifier 08 is shown in FIG. Spike noise 1002 is superimposed on the differential amplifier output F.

In response to the input of the differential amplifier output F, the zero-cross comparator 107 outputs a zero-cross comparator output G to the subsequent drive pulse generating means 114 as shown in FIG. A spike pulse 1004 corresponding to the spike noise 1002 is superimposed on the zero-cross comparator output G.

However, the subsequent drive pulse generating means 114
Has a function of digitally masking a spike pulse 1004 corresponding to the spike noise 1002 shown in FIG. 5, so that the subsequent drive pulse generation unit 114 generates the subsequent drive pulse generation signal J from the start pulse generation unit 113. After the input, the rising and falling times of the spike pulse 1004 correspond to the rising and falling times of the zero-cross comparator output G shown in FIG. 10 (g) corresponding to the zero-crossing 1003 shown in FIG. 10 (f). As shown in FIG. 10 (h), in synchronization with the time except for the pulse width (tc) and the start pulse width (te) corresponding to the battery voltage detected by the battery voltage detection circuit 111. A subsequent drive pulse H having a pulse width (tbh) is output.

The stepping motor 301 is constantly accelerated by the subsequent driving pulse H and can rotate the rotor 303 at a high speed at a rotational speed balanced with the frictional resistance acting on the rotor 303. Here, the subsequent driving pulse generation means 114 determines the pulse width (t
bh) is reduced as the rotation speed of the step motor increases, and the pulse width (tb) optimal for the rotation speed of the step motor is reduced.
h).

In this embodiment, the differential amplifier 908 shown in FIG. 12A does not have the R2C2 and R3C3 low-pass filters shown in FIG. The rise of the output of the zero-cross comparator excluding the spike pulse 1004,
The rotation angle θ corresponding to the fall is approximately −θ _o or π
−θ _o . Brake against rotation of the step motor rotor due to detent torque (θ = 0 to π / 2 or π to 3
(Brake at π / 2) can be sufficiently accelerated and the rotation speed of the rotor can be increased.

Next, an embodiment using a cancel type coil will be described. 15A is a plan view of a vibration alarm driving step motor using a cancel type coil, FIG. 15B is a cross-sectional view taken along the line CC ′ of FIG. 15A, and FIG. 3 (c) is used. The step motor 301 has a rotor 30 provided with an eccentric weight 302.
3, a stator 304, and a drive coil 1502. The drive coil 1502 is
3 and two rotor-generated counter-electromotive voltage detection coils C1504 connected in series with the active drive coil to detect the magnetic pole position of the rotor 303 and having the same DC resistance and self-inductance but different winding directions. It comprises a back electromotive voltage detection coil D1505.

The rotor-generated counter electromotive voltage detection coil C15
04, the back electromotive voltage generated at D1505 will be described. The back electromotive voltage Vc generated in the rotor generated back electromotive voltage detection coil C is obtained by the following equation 5, including the voltage drop Rc · i _C caused by the DC resistance Rc of the rotor generated back electromotive voltage detection coil C.

[0064]

(Equation 5)

[0065] In the number _{5, -Lc · (di c /} dt)
Equivalent self-inductance Lc (production driving coil of the rotor generated counter electromotive voltage detection coil C1504 is the number of turns of the rotor generated counter electromotive voltage detection coil C n _0c, equivalent self-inductance Lc as n _c is Lc = n _0c · n _c / Rm; where Rm is the reverse of the sign of the product of the time change of the drive current _ic and the magnetic resistance of the magnetic circuit of the step motor, and is generated when the drive current _ic changes with time.

Also, -Kc · sin (θ + θ _o ) · (d
θ / dt) is obtained by reversing the sign of the product of the time change of the mechanical coupling coefficient K, sin (θ + θ _o ) with the step motor 301 and the rotation angle θ of the rotor 303, that is, the angular velocity. appear. _θo is the initial angle of the rotor 303. In the plan view of the stator and the rotor shown in FIG. 3C, the magnetic pole N (S) of the rotor permanent magnet 308 of the rotor 303 stopped by the detent torque.
From the position, almost 9 from slit 309 of stator 304
This is the angle up to the 0 degree position.

Next, the rotor-generated counter electromotive voltage detection coil D1
Counter electromotive voltage Vd generated in 505, the voltage drop Rd · i _d by the DC resistance Rd of the rotor generated counter electromotive voltage detection coil D
And the following equation (6).

[0068]

(Equation 6)

Similarly, Vd in Equation 6 is -Ld · (di _d / d
t), - Kd · sin ( θ + θ o) · (dθ / dt) and the sum of Rd · i _d, the drive current ic and -id, DC resistance Rc and Rd, equivalent self-inductance Lc and -ld,
The mechanical coupling coefficients Kc and Kd are i (−i), R, and L, respectively.
Since (−L) is equal to K, the difference from Va is that only the sign of R · i differs due to the different direction of the drive current i.

Further, the output V of the adder described later is obtained by the following equation (7).

[0071]

(Equation 7)

V in Equation 7 is an addition output F 'of an adder 1308 in a block diagram of a high-speed rotation drive circuit for the rotor of the step motor shown in FIG. 13 which will be described later. The drop is cancelled, and the time change of the drive current i causes −2 · GL · (d
i / dt) and the back electromotive voltage generated by rotation of the rotor 303, −2 · G · K · sin (θ + θ _o ) ·
(Dθ / dt).

This −2 · G · K · sin (θ + θ _o ) ·
By detecting when (dθ / dt) becomes zero,
As shown in FIG. 3C, the rotation angle θ (−θ _o , −θ _o +) of the rotor 303 from the position of the magnetic pole N (S) of the rotor permanent magnet 305 of the rotor 303 stopped by the detent torque.
π) can be detected. Here, G is an adder 13
08 gain. It should be noted that -2 · GL ·
Since (di / dt) is a negligible value, it does not affect detection.

The rotor-generated counter electromotive voltage detection coils C and D
Are different from each other in the direction of the drive current i.
Does not contribute to the rotational drive of the motor, and consumes power ineffectively due to the Joule loss of the DC resistances Rc and Rd. However, the output from the adder 1308 is a zero-cross comparator 10 shown in FIG.
7 is at a level at which zero-crossing can be detected sufficiently, so that the rotor-generated counter-electromotive voltage detecting coils C1504 and D150
5 is negligible compared to the power consumption of the drive coil 1502.

FIG. 14 is an explanatory view of an embodiment for driving a rotor of a step motor having a cancel type coil at high speed rotation, and FIG. 13 is an embodiment of a circuit for driving a high speed rotation of a rotor of a step motor having cancel coil shown in FIG. This will be described with reference to a block diagram of the embodiment. In this embodiment, the start pulse generating means 113 generates a pulse composed of a start pulse E and an auxiliary start pulse 201, as shown in FIG.

The adder 1308 shown in FIG. 16 does not have the R3C3, R4C4, and R5C5 low-pass filters shown in FIG.
As described in detail in the circuit diagram of the circuit for digitally masking spike pulses in FIG. 5, the spike pulse generated by spike noise superimposed on the back electromotive voltage added by the adder is digitally masked. It also has a function of calculating the rotation speed of the step motor from the pulse interval of the subsequent drive pulse H, and narrowing the width of the subsequent drive pulse (th) as the rotation speed of the step motor increases.

The operation up to the generation of the starting pulse E is the same as that in FIG. The adder 13 connected to the rotor-generated counter electromotive voltage detection coils C1504 and D1505
The adder output F ′ of 08 is shown in FIG. A spike noise 1402 is superimposed on the adder output F '.
The input of the adder output F ′ causes the zero-cross comparator 107 to output the zero-cross comparator output G as shown in FIG.
Output to

The output G of the zero cross comparator has a spike pulse 1 corresponding to the spike noise 1402.
404 are superimposed. However, since the subsequent drive pulse generation means 114 has a function of digitally masking the pulse 1404 corresponding to the spike noise 1402, the subsequent drive pulse generation means 114 generates the subsequent drive pulse generation signal from the starting pulse generation means 113. After the input of J, the rising and falling of the spike pulse 1404 during the rising and falling times of the zero-cross comparator output G shown in FIG. 14G corresponding to the zero-cross 113 shown in FIG. As shown in FIG. 14H in synchronization with the time except for the time, the battery voltage corresponding to the battery voltage detected by the battery
The matching pulse width (tc) and the starting pulse width (te)
A subsequent drive pulse H having a narrower pulse width (th) is output.

The stepping motor 301 is constantly accelerated by the subsequent driving pulse H, and can rotate the rotor 303 at a high speed at a rotational speed balanced with the frictional resistance acting on the rotor 303. Here, the subsequent driving pulse generation means 114 determines the pulse width (t
h) becomes narrower with an increase in the rotation speed of the step motor,
The pulse width (th) is optimized for the rotation speed of the step motor.

In this embodiment, since the adder 1308 does not have the low-pass filters R3C3, R4C4, and R5C5 shown in FIG. 19 described later, the output F of the adder 1308 is not delayed by the low-pass filter. Therefore, the rotation angle θ corresponding to the rise and fall of the output of the zero-cross comparator is substantially −θ0.
Or π−θ0.

Compared to the case where the low-pass filter is provided, a brake (θ = 0 to π / 2 or π to 3) against rotation of the rotor of the step motor due to the detent torque is provided.
(Brake at π / 2) can be sufficiently accelerated and the rotation speed of the rotor can be increased. In this embodiment, when the voltage applied to the driver of the step motor is 3
V, the pulse width of the subsequent drive pulse was about 3 ms, the number of revolutions of the rotor 303 per minute was about 6000 rpm, and the drive current (peak value) was as small as about 2 mA.

Next, an embodiment in which a circuit for digitally masking a spike pulse is removed from the subsequent drive pulse generating means 114 and a low-pass filter is attached to the adder 1308 will be described. Further, FIG. 17 is an explanatory view of an embodiment for driving the rotor of the step motor shown in FIG. 17 at high speed, and is the same as FIG. 14 up to FIG. FIG. 18 shows a circuit configuration diagram of the adder 1708.

The adder 1708 includes a differential amplifier 1601, a differential amplifier 1602 connected to the rotor-generated counter-electromotive voltage detection coil C1504, the rotor-generated counter-electromotive voltage detection coil D1505, and the differential amplifiers 1601 and 1602, respectively. And an addition amplifier 1903 having a low-pass filter formed by R3 and C3 with an amplification degree of R3 / R6 or R3 / R7 connected to the R4C4 and R5C5 low-pass filters connected to the output terminals of the R4C4 and R5C5 low-pass filters. I have.

The output of the adder 1708 is also expressed by equation 9 (gain G has a frequency characteristic by a low-pass filter), but actually, the differential amplifiers 1601 and 160
The outputs corresponding to the generation time of the subsequent drive pulse H of No. 2 have the same sign, and cannot be removed by the addition amplifier 1903, and appear as so-called spike noise overlapping with the addition output F ′. Here, the spike noise refers to not only the noise corresponding to the fall of the subsequent drive pulse H, but also the noise corresponding to the rise to the fall of the subsequent drive pulse H.

If the added output F ′ crosses zero at an arbitrary time due to the spike noise, an unnecessary subsequent drive pulse H is generated by the drive pulse generation microcomputer 1709.
And the rotor 303 cannot rotate normally. Therefore, in order to remove the spike noise, R
A 4C4, R5C5 low-pass filter and a low-pass filter formed by R3, C3 are required.

The cut-off frequency of the R3C3 low-pass filter can be obtained by Expression 8.

[0087]

(Equation 8)

The cut-off frequency of the R4C4 low-pass filter can be obtained by Expression 9.

[0089]

(Equation 9)

The cut-off frequency of the low-pass filter formed by R5 and C5 can be obtained by Expression 10.

[0091]

(Equation 10)

In order to remove the spike noise, it is necessary to set f1, f2, and f3 in the range from fr to 4fr, where fr is the maximum rotation frequency of the stepping motor. Although the high-pass spike noise corresponding to the rise and fall of the subsequent drive pulse H can be removed from the spike noise by the low-pass filter, the spike noise at frequencies lower than the cutoff frequencies f1, f2, and f3 is removed. Since it is not possible, within the generation time of the synchronizing pulse C, the starting pulse E, and the subsequent driving pulse H,
A clamp 1802 occurs in the adder output F shown in FIG.

However, the zero cross output of the zero cross comparator 107 due to the spike pulse corresponding to the trailing edge of the subsequent drive pulse H is eliminated, and the subsequent drive pulse H can be generated only by the zero cross of the back electromotive voltage generated by the rotor. There is no problem in rotational stability.

[0094] by the low-pass filter, the adder output F 'in the resulting time lag, the rise of the zero crossing comparator output G, the rotation angle theta which corresponds to the falling deviates from - [theta] _o or π-θ _o. The rotation angle θ
In order to optimize the detent torque and the excitation torque generated by the drive current flowing through the drive coil 1502 for the rotational driving of the rotor 303, and to optimize the starting characteristics and the rotational speed of the rotor 303, the detent torque corresponds to the detent torque. It is desirable to be between the magnetic equilibrium point and the excitation equilibrium point corresponding to the excitation torque. As shown in FIG.
θ _o, or that there from π-θ _o to π desirable.

When the delay of the rotation angle θ is larger than θ _o , as shown in FIG. 19 (f) (FIGS. 19 (a) to (e) are the same as FIG. The zero cross level of the zero cross comparator 107 is shifted from the zero level to the plus side (zero cross level 2001) and shifted to the minus side (zero cross level 2002) to set the zero cross comparator 107 in the temporally forward direction. Let it.

Then, as shown in FIG. 19 (g), the rise and fall of the zero-cross comparator output G are temporally advanced, and as shown in FIG. 19 (h), the generation of the subsequent drive pulse H is temporally reduced. The rotor 303
It is necessary to recover the delay of the rotation angle θ. The magnetic pole position detecting means having the zero cross comparator 107
By setting the zero cross level of the zero cross comparator 107 to be shifted from the zero level to a predetermined level, it is possible to detect the back electromotive voltage before and after the zero level of the back electromotive voltage. Can be delayed as well as advanced.

Next, another embodiment of the high-speed rotation drive circuit for the rotor of the stepping motor having the cancel type coil will be described with reference to the block diagram of FIG. FIG.
0, the configuration different from that of FIG. 13 is the same as that of FIG.
The rotation / non-rotation detection circuit 211 detects rotation / non-rotation of the motor 3 and outputs a rotation / non-rotation signal to a pulse interval setting unit 2116 and a starting pulse generation unit 2113. Hereinafter, FIG.
3, the description is omitted.

FIG. 21 is an explanatory view of another embodiment for driving a rotor of a step motor having a cancel type coil at a high speed. FIG. 20 is a circuit diagram of a high speed rotation drive circuit of a step motor having a cancel type coil. A description will be given along a block diagram of another embodiment.

FIG. 21 is different from FIG. 14 in that the starting pulse generating means 2113 generates the starting pulse width signal L
Accordingly, the start pulse (pulse width is set to correspond to the battery voltage detected by the battery voltage detection circuit 111 and the rotation non-rotation signal P of the rotation non-rotation detection circuit 211
When the rotor 303 rotates ter, when it does not rotate te
n) and the auxiliary start pulse (the pulse width is tgr when the rotor 303 rotates, and tgn when it does not rotate) in FIG.
As shown in (e) ((f), (g),
((H) is also indicated by a solid line when the rotor 303 rotates, and by a broken line when the rotor 303 does not rotate). The start pulse generation signal O indicates that tdr (when the rotor 303 rotates) or tdn (when the rotor 303 rotates) from the falling of the matching pulse C. Rotor 30
After that, the output is outputted to the drive circuit 110.

In this embodiment of the high-speed rotation drive circuit for the rotor of the step motor, the rotation non-rotation detection circuit 211 is added to the embodiment of the high-speed rotation drive circuit for the rotor shown in FIG. Not only the battery voltage detected by the circuit 111 but also the synchronizing pulse C
The output time and pulse width of the starting pulse E output from the starting pulse generating means 2113 can be set in accordance with the rotation or non-rotation of the rotor 303 due to the driving of.

However, it takes a predetermined time from the fall of the phase matching pulse C for the rotation / non-rotation detecting circuit 211 to detect the rotation or non-rotation of the rotor 303. Even if the 303 rotates, the starting pulse E having a wider pulse width than the subsequent driving pulse H is required.

The rotor-generated counter electromotive voltage detection coil C15
FIG. 21 (f) shows the addition output F 'of the adder 1308 connected to the input terminal 04 and D1505. The input of the addition output F ′ causes the zero-cross comparator 107 to operate as shown in FIG.
As shown in (g), the zero-cross comparator output G is output to the subsequent drive pulse generation means 114. The subsequent driving pulse generating means 114 is provided with the starting pulse generating means 2.
After the input of the subsequent drive pulse generation signal J from 113,
Synchronized with the rising and falling times of the zero-cross comparator output G corresponding to the zero-crossing 2203 shown in FIG. 21 (f), and as shown in FIG. The matching pulse width (t) corresponding to the detected battery voltage
c) and a subsequent drive pulse having a pulse width (th) smaller than the start pulse width (ter, ten).

The stepping motor 301 is constantly accelerated by the subsequent driving pulse H, and can rotate the rotor 303 at a high speed at a rotational speed balanced with the frictional resistance acting on the rotor 303.

Next, a method of winding the drive coil in the cancel type coil shown in FIG. 22 will be described. Active drive coil 1503, rotor generated back electromotive voltage detection coil C15
04, drive coil 1502 composed of D1505
22 is pulled out from a wire guide 2307 by a wire 2306 shown in FIG. 22 and the wire 2306 is hooked on a coil winding frame 2305. Wire 2306 by wire hooking pin 2
Hook on 308.

The wire 2306 is connected to the coil bobbin 2
305, and the rotor-generated counter electromotive voltage detection coil C1504 is wound around the coil core 307 in the opposite direction to the rotor-generated counter electromotive voltage detection coil D1505.
6 is hooked on the wire hooking pin 2308, thereby hooking the wire 2306 on the coil winding frame 2305, and the actual driving coil 1503 is wound around the coil winding core 307 in the opposite direction to the rotor-generated back electromotive voltage detection coil D1505.

Thus, the wire 2306 is hooked on the wire guide 2307. The two coil terminals of the rotor-generated counter electromotive voltage detection coil C1505 are coil terminals 1, 2301, and coil terminals 4 and 2304, respectively, and the two coil terminals of the rotor-generated counter electromotive voltage detection coil C1504 are coil terminals 2, 2302, respectively. , Coil terminal 4, 230
4, two coil ends of the active drive coil 1503 are connected to coil terminals 2, 2302 and coil terminals 3, 230, respectively.
3 and unnecessary wire 230 for drive coil 1502
6 and cut the coil core 30 of the drive coil 1502.
Automatic winding to 7 is completed.

Next, an embodiment of the vibration modulation of the vibration alarm shown in FIG. 23 will be described. The drive ON / OFF generation circuit 106 in FIGS. 1, 9, 13, 17, and 20 is obtained from the vibration alarm set / reset circuit 105 shown in FIG.
In response to the input of the vibration alarm generation pulse A shown in (1), a drive on / off signal B consisting of a pulse train of a drive on time ton corresponding to the drive on of the step motor and a drive off time toff corresponding to the drive off is output. By the drive on / off signal B, the step motor is driven to rotate within the drive on time ton, and stops at the drive off time toff.

As a result, the vibration of the vibration alarm is modulated, and compared to a constant vibration without modulation,
The vibration of the eccentric weight of the step motor can be more strongly transmitted to the tactile organ of the arm via the watch case.

Next, a description will be given of a second embodiment of the vibration modulation of the vibration alarm shown in FIG. 1, 9, and 1
3, drive on / off generation circuit 1 in FIGS. 17 and 20
Reference numeral 06 denotes a drive on / off signal B composed of a pulse of a drive on time ton corresponding to the drive on of the step motor in response to the input of the vibration alarm generation pulse A shown in FIG. 24A from the vibration alarm set / reset circuit 105. Is output.

As shown in FIG. 24 (c), the subsequent drive pulse generation means outputs a constant pulse width (t
h), the subsequent drive pulse width is gradually reduced, and the subsequent drive pulse interval is measured. When the subsequent drive pulse interval becomes ts, the subsequent drive pulse width is gradually increased. To increase. Then, a constant pulse width (th) is generated for the time tcon after the subsequent drive pulse interval becomes tf.

After that, the above is repeated. As a result, the rotation speed of the rotor of the stepping motor increases or decreases, so that the vibration of the vibration alarm is modulated. The vibration of the eccentric weight of the arm can be transmitted more strongly to the tactile organ of the arm.

Next, a calculation result of theoretically simulating the number of revolutions per minute of the rotor will be described. The method of driving the rotor detects the position of the rotor by detecting the position of the rotor from the back electromotive voltage (hereinafter referred to as rotor generated back electromotive voltage) induced in the drive coil by the magnetic flux generated by the rotating rotor. This is an optimum driving method in which a driving current is supplied to a driving coil in synchronization with time to accelerate and drive the rotor.

First, the rotation angle θ of the rotor is obtained by Expression 11. Here, the rotation angle θ of the rotor is shown in FIG.
As shown in the plan view of the stator and the rotor of FIG.
Assuming that the magnetic equilibrium point in (c) is θ = 0, the clockwise direction is a positive angle.

[0114]

[Equation 11]

Next, the drive current i is obtained by Expression 12.

[0116]

(Equation 12)

Here, J is the moment of inertia of the rotor, r
Is the fluid resistance coefficient of the rotor, K is the electromechanical coupling coefficient, θ_o
Is the initial angle of the rotor, Ts is the maximum detent torque
Value, T _LIs the load torque, and Mg is the maximum gravity mode of the eccentric weight.
, L is the self-inductance of the drive coil, R is the drive
DC resistance of the moving coil, u (t) is a unit function at time t, τ
Is the drive pulse width, V is the voltage applied to the motor driver, R
_o(I, V) is the ON resistance of the motor driver.

The initial angle of the rotor is θ _o (π / 4 = 0.
785 rad), the back electromotive voltage generated by the rotor, −K · s
Simulation of a rotor in which the rotor is accelerated by a rotation angle θ (−θ _o , −θ _o + π) at which in (θ + θ _o ) · (dθ / dt) becomes zero or a subsequent drive pulse (pulse width τ) at a time. FIG. 25 shows the calculation result (time change of the number of rotations of the rotor per minute).

As shown in FIG. 25, for each parameter value, the applied voltage is 3.0 (V), and the drive coil DC resistance (R +
R _o ) is 200 (Ω), and the self inductance L is 200
mH and moment of inertia J are 2.8 × 10 ⁻⁹ (kg
m ² ) and the fluid resistance coefficient r is 16.0 × 10 ⁻¹¹ (Nms
/ Rad), and the electromechanical coupling coefficient K is 5.3 × 10 ⁻³ (N
m / A) and the detent torque Ts is 5.3 × 10 ^-6 (N
m), the load torque T _L is 0.0 (Nm), and the moment Mg due to the gravity of the eccentric weight is 6.0 × 10 ⁻⁶ (Nm).

Initial stop angle position θ of rotor, -sin ^-1
(Mg / 2Ts) is about -0.06 rad, the initial angular velocity (dθ / dt) of the rotor is 0 rad: the initial drive current i is 0 mA, the starting pulse width is 20 ms, and the pulse width τ4
In the time change of the number of rotations of the rotor per minute when the number of subsequent drive pulses of ms is 114, the maximum number of rotations is 70.
The stop time of the rotor after 00 rpm and the end of the subsequent drive pulse (about 0.55 s) was about 0.15 s.

The drive current is 15 mA at the time of starting,
At a constant high speed rotation after about 0.5 s, the value was about 3 mA. By this simulation calculation of the number of rotations of the rotor, the number of rotations of the rotor detects the position of the rotor from the back electromotive voltage generated by the rotor, and drives the drive current to the drive coil in synchronization with the time when the position of the rotor is detected. It has been found that the rotation speed is 3000 rpm or more depending on the method of driving the rotor to accelerate.
The driving current (peak value) during constant high-speed rotation is about 3 m.
It turned out that it can be reduced to A.

Next, the stator that can be used in the present invention will be described. In the above embodiment, the description has been given using the flat two-pole separated type stator having the slit 261 and the step 262 shown in FIG. 26A, but the present invention is not limited to this. 26, a flat two-pole integrated stator having a notch 263 without a step as shown in FIG.
A flat two-pole separated stator having only a slit as shown in (c) and having no step, or a flat two-pole integrated stator having no slit and no step as shown in FIG. 26D can be realized. In the case of the flat two-pole stator shown in FIG. 26 (d), it can be driven by preparing a plurality of start pulses having different pulse widths and selectively outputting the optimum start pulse.

In the electronic equipment with a built-in step motor of the present invention, an embodiment of a wristwatch with a vibration alarm having a built-in step motor for vibration alarm has been described. However, the present invention is directed to a step motor that moves an hour hand through a wheel train. It is needless to say that the present invention can also be applied to a high-speed rotation technology of the step motor in a wristwatch having a built-in.

[0124]

As has been shown by the above detailed description, the present invention has a low power consumption, a durable, easy-to-assemble, stable starting and high-speed stepping motor, reliability. There is an effect that a small electronic device with reliability can be provided. In particular, a magnetic pole position detecting means for detecting a magnetic pole position of the rotating rotor with respect to the flat stator based on a back electromotive voltage generated in the back electromotive voltage detection coil, and the drive pulse generating means, Since the output timing of the pulse signal is controlled based on the detection signal, a step motor that rotates at high speed can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a high-speed rotation drive circuit of a rotor of a step motor having a separation type coil.

FIG. 2 is an explanatory diagram for driving a rotor of a step motor having a separation type coil at a high speed.

FIG. 3 is a plan view of a vibration alarm driving step motor having a separation type coil.

FIG. 4 is a circuit configuration diagram of a differential amplifier of a high-speed rotation drive circuit of a step motor having a separation type coil.

FIG. 5 is a configuration diagram of a circuit that digitally masks spike pulses.

FIG. 6 is a time chart of a circuit for digitally masking a spike pulse.

FIG. 7 is a plan view of a wristwatch with a vibration alarm incorporating a step motor according to the present invention.

FIG. 8 is a time change of a drive pulse of the step motor of the present invention.

FIG. 9 is a block diagram of an embodiment of a high-speed rotation drive circuit of a step motor rotor having a tapped coil.

FIG. 10 is an explanatory diagram for driving a rotor of a step motor having a tapped coil to rotate at high speed.

FIG. 11 is a plan view of a vibration alarm driving step motor having a tapped coil.

FIG. 12 is a circuit configuration diagram of a differential amplifier of a high-speed rotation drive circuit of a step motor having a tapped coil.

FIG. 13 is a block diagram of an embodiment of a high-speed rotation drive circuit of a rotor of a step motor having a cancel coil.

FIG. 14 is an explanatory view of still another embodiment for driving a rotor of a step motor having a cancel coil to rotate at a high speed.

FIG. 15 is a plan view of a vibration alarm driving step motor having a cancel coil.

FIG. 16 is a circuit configuration diagram of an adder having no low-pass filter.

FIG. 17 is an explanatory diagram for driving a rotor of a step motor having a cancel coil to rotate at a high speed.

FIG. 18 is a circuit configuration diagram of an adder having a low-pass filter.

FIG. 19 is an explanatory diagram for recovering a time delay of an adder output.

FIG. 20 is a block diagram of another embodiment of a high-speed rotation drive circuit for a rotor of a step motor having a cancel coil.

FIG. 21 is an explanatory view of another embodiment for driving a rotor of a step motor having a cancel coil to rotate at a high speed.

FIG. 22 is an explanatory diagram of a method of winding a drive coil having a cancel coil.

FIG. 23 is an example of vibration modulation of a vibration alarm.

FIG. 24 is a second embodiment of the vibration modulation of the vibration alarm.

FIG. 25 is a simulation calculation result of a temporal change in the rotation speed of a step motor.

FIG. 26 is a plan view showing a flat two-pole stator that can be used in the present invention.

[Explanation of symbols]

 A Vibration alarm generation pulse B Drive on / off signal C Phase matching pulse D Battery voltage detection instruction signal E Start pulse F Differential amplification output F 'addition output G Zero cross comparator output H Subsequent drive pulse 301 704 1101 1501 Step motor 302 Eccentric weight 303 Rotor 305 705 1102 1502 Drive coil 1503 Active drive coil 306 1103 Back electromotive voltage detection coil 1504 Rotor generated back electromotive voltage detection coil C 1505 Rotor generated back electromotive voltage detection coil D

Claims (24)

[Claims] 1. An electronic device having a motor including a rotor having a stator and a permanent magnet and a drive coil magnetically coupled to the stator, a drive signal generation for outputting a drive signal for driving the motor. Means,
A drive circuit for supplying a drive current to the drive coil based on a drive signal from the drive signal generating means, the stator for transmitting a magnetomotive force generated in the drive coil to the rotor, and a rotation circuit of the rotor. A back electromotive voltage detection coil for detecting a back electromotive voltage, and magnetic pole position detecting means for detecting a magnetic pole position of the rotating rotor with respect to the stator based on a back electromotive voltage generated in the back electromotive voltage detection coil; The electronic device according to claim 1, wherein the drive signal generation unit controls output timing of the drive signal based on a detection signal from the magnetic pole position detection unit. 2. The motor according to claim 1, wherein the motor has a two-pole flat stator.
2. The electronic device according to claim 1, wherein the electronic device is a step motor including a rotor having a pole permanent magnet and a drive coil. 3. The magnetic pole position detecting means according to claim 1, further comprising a zero cross comparator for detecting that the back electromotive voltage generated in the back electromotive voltage detection coil has reached zero level and outputting a detection signal. Or the electronic device according to 2. 4. The driving signal from the driving signal generating means is a pulse signal, and the pulse signal includes a starting pulse for starting rotation of the stopped rotor and a driving pulse for continuously driving the started rotor. The electronic device according to claim 1, further comprising a subsequent drive pulse. 5. A starting pulse for rotating and starting a rotor in a stopped state is output after the phase matching pulse for adjusting the magnetic poles of the rotor facing the magnetic poles generated in the stator to the same polarity, and after the phase matching pulse. 5. The electronic apparatus according to claim 4, further comprising: a start pulse for generating a magnetic pole having the same polarity as the magnetic pole of the rotor magnet on the stator facing the magnetic pole of the rotor. 6. The electronic device according to claim 5, wherein the starting pulse has a wider pulse width than a subsequent driving pulse. 7. The electronic apparatus according to claim 6, wherein the starting pulse is a plurality of pulse trains having a wider pulse width than a subsequent driving pulse. 8. The plurality of pulse trains are composed of a first start pulse having a wider pulse width than a subsequent drive pulse and a second start pulse having a narrower pulse width than the first start pulse. The electronic device according to claim 7, wherein: 9. The electronic apparatus according to claim 4, wherein the pulse width of the subsequent drive pulse is reduced as the rotation speed of the rotor increases. 10. The electronic apparatus according to claim 1, wherein the back electromotive voltage detection coil is independently wound around an inner peripheral side of the drive coil. 11. The electronic device according to claim 1, wherein the drive coil also serves as a back electromotive voltage detection coil. 12. The electronic apparatus according to claim 11, wherein a tap is taken out from a part of the drive coil, so that a part of the drive coil also serves as a back electromotive voltage detection coil. 13. A magnetic pole position detecting means, comprising: a differential amplifier for differentially amplifying a back electromotive force generated in a back electromotive voltage detection coil; The electronic device according to claim 10, further comprising a zero-cross comparator that detects the arrival and outputs a detection signal. 14. The back electromotive voltage detection coil is composed of two back electromotive voltage detection coils having substantially the same DC resistance and self-inductance but having different winding directions, and is connected in series to the drive coil. The electronic device according to claim 1, wherein: 15. A magnetic pole position detecting means, comprising: an adder for adding back electromotive voltages respectively generated in two back electromotive voltage detection coils; and a counter electromotive voltage added by the adders reaching a zero level. 15. The electronic apparatus according to claim 14, further comprising: a zero-crossing comparator that detects the detection signal and outputs the detection signal. 16. The electronic apparatus according to claim 14, wherein the back electromotive voltage detection coil is configured to be wound in multiple layers around the inner periphery of the drive coil. 17. The electronic device according to claim 15, wherein the adder has a low-pass filter for cutting spike noise superimposed on the back electromotive voltage. 18. The driving signal generating means includes masking means for digitally masking a detection signal from a zero-cross comparator corresponding to a spike noise superimposed on the back electromotive voltage added by the adder. The electronic device according to claim 15, wherein 19. The electronic device according to claim 13, wherein the differential amplifier has a low-pass filter that cuts spike noise superimposed on the differentially amplified back EMF. 20. A drive signal generation means, comprising: a mask means for digitally masking a detection signal from the zero-cross comparator in response to a spike noise superimposed on a back electromotive force differentially amplified by the differential amplifier. 14. The electronic device according to claim 13, comprising: 21. The magnetic pole position detecting means is capable of detecting a magnetic pole position of a rotating rotor while the rotor is rotating at a high speed from a stopped state based on a back electromotive voltage generated in the back electromotive voltage detection coil. The electronic device according to claim 1, wherein: 22. The magnetic pole position detecting means shifts a zero cross level of the zero cross comparator of the magnetic pole position detecting means from a zero level to a predetermined level and sets the zero cross level. The electronic device according to claim 3, wherein the electromotive voltage can be detected. 23. The electronic apparatus according to claim 2, wherein the flat stator of the step motor is a separated type or an integrated type. 24. A battery for supplying power to the drive circuit,
3. A battery voltage detecting circuit according to claim 1, further comprising a battery voltage detecting circuit for detecting a voltage of the battery, and a pulse width setting means for setting an optimum pulse width of the driving pulse based on an output signal from the battery voltage detecting circuit. Electronics.