JPH06235777A - Electronic appliance provided with oscillation alarm - Google Patents

Abstract

PURPOSE:To provide a step motor for oscillation alarm being employed in an electronic appliance. CONSTITUTION:In an electronic appliance provided with an oscillation alarm where the oscillation of a step motor, generated by driving a step motor having a rotor equipped with an eccentric weight, is transmitted through the case body to an arm, the step motor has two pole flat stator and the driving pulse for the step motor comprises a starting pulse, constituted of a phase matching pulse C and a starting pulse E, and a driving pulse H following thereto. The step motor is driven at high speed by the driving pulse H synchronized with the zero-cross time of counter electromotive force induced in a counter electromotive force detection coil 306.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a step motor incorporated in an electronic device with a vibration alarm for notifying an alarm by transmitting the vibration of the step motor to an arm.

[0002]

2. Description of the Related Art A conventional wristwatch with a vibration alarm has a built-in ultrasonic motor as a vibration source, and transmits the vibration of an eccentric rotor of the ultrasonic motor to a wrist via a watch case to notify as a vibration alarm. , Actual Kaihei 2-629
It is disclosed in Japanese Patent Publication No.

[0003]

However, the ultrasonic motor has a problem due to the principle structure of the ultrasonic motor, as will be described below. First, there is the problem of wear resistance. The stator includes a piezoelectric element, a vibrating body bonded to the piezoelectric element for transmitting vibration of the piezoelectric element, and a comb tooth portion attached to the vibrating body to increase the amplitude of vibration of the vibrating body. The eccentric rotor is pressed against the comb teeth by a spring, and rotates when the piezoelectric element vibrates. Since the eccentric rotor is pressed against the comb teeth by the spring, there arises a problem of wear resistance of the contact portion between the eccentric rotor and the comb teeth. Moreover, since the vibration amplitude of the piezoelectric element is small, the piezoelectric element, the vibrating body, the comb tooth portion,
There is a problem in that the eccentric rotor must have strict component accuracy and assembly accuracy. Furthermore, since the efficiency is low, the power consumption increases. In a research presentation titled "AQ (Analog Quartz) Development with Vibration Alarm Using an Ultrasonic Motor" at the 1991 Autumn Meeting of the Japan Society of Watchmaking,
The driving current is 60 when the eccentric rotor rotates at 6000 rpm.
It is reported to be mA.

According to the present invention, the stepping motor is used as the vibration source, which has the durability of rotation of the rotor, is easy to assemble, consumes less power, and can be stably started and rotated at high speed even if acceleration is applied by shaking the arm. , A reliable small vibration alarm electronic device with a vibration alarm (for example, a wristwatch) is provided.

[0005]

In order to achieve the above object, the present invention has the following constitution. When the alarm time arrives, the motor is driven to rotate the eccentric weight, and the vibration alarm electronic device that transmits the vibration of the eccentric weight to the arm through the case body is a rotor having a two-pole flat stator and two-pole permanent magnet. A step motor composed of a drive coil magnetically coupled to the flat stator, a drive pulse generating means for outputting a pulse signal for driving the step motor based on an alarm signal, and the drive pulse generating means. A drive circuit for supplying a drive current to the drive coil, the flat stator for transmitting the magnetomotive force generated in the drive coil to the rotor, and the counter electromotive voltage generated by the rotation of the rotor based on the pulse signal And a counter electromotive force detection coil for rotating the flat stator based on the counter electromotive voltage generated in the counter electromotive voltage detection coil. Magnetic pole position detecting means for detecting the magnetic pole position of the inner rotor, and the drive pulse generating means controls the output timing of the pulse signal based on the detection signal from the magnetic pole position detecting means. I am trying.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 7 shows a plan view of a wristwatch with a vibration alarm incorporating a step motor according to the present invention. 701 is a watch case, 704 is a vibration alarm step motor composed of an eccentric weight 302 attached to the rotating shaft of a rotor 303, a drive coil 705 and the like, 702 is a wristwatch module having a drive circuit of the step motor, and 703 is a step motor. It is a drive battery. The step motor 704 is shown in FIG.
As shown in the plan view of the stator and rotor in (c), the flat 2
It is a step motor having a pole type stator 304 and a two-pole rotor permanent magnet 308. Here, as long as the functions described below can be realized, the stator hole 310 can be formed as shown in FIG.
A structure having two slits 309 shown in (c), and a semicircle formed by cutting the stator 304 in a direction connecting the two slits 309 (called a vertical direction) is vertically shifted It is not limited. The step motor 704 can be arranged between the timepiece case 701 and the wristwatch module 702 without generating an unused space. Further, the step motor 704 has a feature that it can be arranged without being stacked on the step motor driving battery 703. Then, when the step motor 704 is driven by the drive pulse having a constant cycle shown in FIG. 8, the number of revolutions per minute is about 1000 rpm, so that the vibration of the step motor can be transmitted to the arm and notified as a vibration alarm. However, in order to generate a centrifugal force of about 0.098 N that acts on the eccentric weight necessary to more reliably transmit the vibration to the arm, the number of revolutions per minute of the rotor is 3000 rp.
Even when acceleration is applied to the step motor 704 by setting the distance to m or more and shaking the arm, the rotation is kept stable and the reliability as a vibration alarm is improved.

First, a high-speed rotational driving method of the rotor of the present invention for increasing the number of revolutions per minute of the rotor in the separated coil to about 3000 rpm or more will be described. Figure 3
FIG. 3A is a plan view of a vibration alarm driving step motor in the separated coil, and FIG. 3B is C of FIG. 3A.
FIG. 3 is a cross-sectional view taken along the line C ′ of FIG.
(C), the step motor 301 is an eccentric weight 302
Is provided with a rotor 303, a stator 304, a drive coil 305, and a counter electromotive voltage detection coil 306. One back electromotive force detection coil 306 is separated from the drive coil 305, and is wound around the inner circumference of the drive coil 305 with respect to the coil core 307 as shown in FIG. 3B. There is.

A counter electromotive voltage generated in the counter electromotive voltage detection coil will be described.

Back electromotive force V generated in the back electromotive force detection coil
a can make the current ia flowing through the back electromotive force detection coil zero, so that the DC resistance Ra of the back electromotive force detection coil causes
When the counter electromotive voltage −La · (dia / dt) due to the time change of the voltage drop Ra · ia and the current ia is neglected (La is the self-inductance of the counter electromotive voltage detection coil 306), it is calculated by the following formula 1.

[Equation 1]

In Equation 3, -M (di / dt) is the mutual inductance M between the counter electromotive voltage detection coil 306 and the drive coil 305 (the mutual inductance M is the drive coil 305 and the counter electromotive voltage detection coil 306, respectively). When the number of turns is na0 and na, it is expressed as M = k · na0 · na / Rm, where k is a proportional constant, Rm is the magnetic resistance of the magnetic circuit of the step motor, and the drive current i (hereinafter, when the drive pulse is off). (Which also means current) is the reverse of the sign of the product of the change over time, which occurs when the drive current i changes over time, and −Ka · sin (θ + θ ₀ ) · (dθ / dt) is the same as that of the step motor 301. Mechanical coupling coefficient Ka, sin
The product of (θ + θ ₀ ) and the rotational angle θ of the rotor 303 over time, that is, the sign of the product of the angular velocities is reversed, and is generated by the rotation of the rotor 303. θ ₀ is the initial angle of the rotor 303, and in the plan view of the stator and rotor shown in FIG.
From the magnetic pole N (S) position of the rotor permanent magnet 308 of No. 03,
It is an angle from the slit 309 of the stator 304 to a position of approximately 90 degrees.

Further, the output Vga of the differential amplifier described later
Is calculated by the following equation 2.

[Equation 2]

Vga of the equation 4 is the differential amplification output F of the differential amplifier 108 in the block diagram of the high-speed rotation driving circuit of the rotor of the step motor shown in FIG.
By detecting when Ka · sin (θ + θ ₀ ) · (dθ / dt) becomes zero, the magnetic pole N (S) of the rotor permanent magnet 308 of the rotor 303 stationary by the detent torque shown in FIG. 3C is detected. Rotor 30 from position
The rotation angle θ (−θ ₀ , −θ ₀ + π) of 3 can be detected. Here, Ga is the gain of the differential amplifier 108 (hereinafter, including the sign). In addition, -Ga-M-
Since (di / dt) can be ignored, it does not affect the detection.

The structure of the block diagram of the embodiment of the high-speed rotation drive circuit for the rotor of the step motor having the separated coil shown in FIG. 1 will be described. First, the drive coil 305 of FIG.
Is separated from the counter electromotive voltage detection coil 306, the drive coil 305 is connected to the drive circuit 110, and the counter electromotive voltage detection coil 306 is connected to the differential amplifier 108. FIG. 1 shows a vibration alarm set / reset circuit 105 that outputs a vibration alarm generation pulse A at a vibration alarm time, a drive on / off generation circuit 106 that outputs a drive on / off signal B when the vibration alarm generation pulse A is input, and a battery. When the voltage detection instruction signal D is input, the battery voltage detection circuit 111 that detects the battery voltage and outputs the battery voltage rank signal I, the phase adjustment pulse generator 112 that outputs the phase adjustment pulse C and the battery voltage detection instruction signal D, Starting pulse generating means 11 for outputting a starting pulse E and a subsequent drive pulse generating signal J
3. By inputting the subsequent drive pulse generating means 114 for outputting the subsequent drive pulse H and the battery voltage rank signal I, the step motor 301 is given an acceleration that is generated by shaking the arm for each battery voltage. Even if the stepping motor 301 is started, the phase matching pulse width, the starting pulse width, the subsequent driving pulse width, the phase matching pulse and the starting pulse, which are set so as to stably start and stably rotate at high speed, are set. Pulse width setting means 115 for outputting a phase matching pulse width signal K, a starting pulse width signal L, a subsequent drive pulse width signal M, a pulse interval signal N, and a pulse for outputting a starting pulse generation signal O corresponding to the pulse interval of Drive pulse generation microcomputer 1 having interval setting circuit 116
09, the phase matching pulse C, the starting pulse E, and the subsequent drive pulse H are input, the drive coil 3
A drive circuit 110 for supplying a drive current to the motor 05, a drive coil 305 for driving the step motor 301, and a counter electromotive voltage detection coil 306 for detecting a counter electromotive voltage generated by the rotation of the rotor 303. The differential amplifier 10 which differentially amplifies the counter electromotive voltage Va generated in the counter electromotive voltage detection coil 306 and outputs a differential amplified output F.
8, differential amplifier output F which is the output of the differential amplifier 108
The zero cross comparator 107 outputs the zero cross comparator output G to the subsequent drive pulse generating means 114.

FIG. 2 is a block diagram of an embodiment of a high-speed rotation drive circuit for a step motor rotor having a separation type coil shown in FIG. 1 for driving the rotor of a step motor having a separation type coil at high speed. It will be described with reference to the drawing. First, at the set vibration alarm time, the vibration alarm set / reset circuit 105 outputs the vibration alarm generation pulse A shown in FIG. 2A, and the drive ON / OFF generation circuit 106 drives ON / OFF shown in FIG. 2B. The off signal B is output. The phase matching pulse generating means 112 outputs the phase matching pulse C shown in FIG. 2C in order to start the rotor 303, and the starting current is supplied by the driving circuit 110 to the driving coil 101 to rotate the rotor 303. However, at this time, it is not known whether the rotor permanent magnet 308 of the rotor 303 is stationary at a position that can be activated by the phase matching pulse C. That is, if the polarity of the magnetic pole generated in the stator 304 excited by the phase 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 is Although 303 rotates, if the polarity is different, the rotor 303 does not rotate.
However, the polarity of the magnetic pole generated in the stator 304 excited by the subsequent drive pulse, that is, the starting pulse E and the subsequent drive pulse H by the phase matching pulse C is opposed to the magnetic pole of the stator 304 of the rotor 303. Since the polarity is the same as that of the magnetic poles of the rotor permanent magnet 308, the following drive pulse can rotate the rotor 303.

The phase matching pulse generating means 112 is shown in FIG. 2D after t ₀ from the rising of the phase matching pulse C.
Output a battery voltage detection instruction signal D to the battery voltage detection circuit 111. The battery voltage detection circuit 111 detects a battery voltage and outputs a battery voltage rank signal I to the pulse width setting means 115. The pulse width setting means 115 can stably start the step motor 301 and stably rotate it at a high speed even when the step motor 301 is subjected to an acceleration that is generated by shaking the arm with respect to the battery voltage. Phase matching pulse width, starting pulse width, subsequent driving pulse width, phase matching pulse width signal K, starting pulse width signal L, and subsequent driving pulse corresponding to the phase matching pulse and the starting pulse interval The width signal M and the pulse interval signal N are phase-matched by the pulse generator 11 respectively.
2, output to the starting pulse generating means 113, the subsequent drive pulse generating means 114, and the pulse interval setting means 116. The phase-matching pulse generator 112 generates a phase-matching pulse C having a pulse width (tc) corresponding to the battery voltage detected by the battery voltage detection circuit 111 based on the phase-matching pulse width signal K.
Is output to the drive circuit 110. The pulse interval setting means 116 outputs a starting pulse generation signal O formed from the phase matching pulse C and the pulse interval signal N to the starting pulse generating means 113.

The starting pulse generating means 113 is responsive to the starting pulse width signal L to detect the battery voltage detecting circuit 111.
With the starting pulse E having a pulse width (te) corresponding to the battery voltage detected by t and the falling tf of the starting pulse E, an auxiliary starting pulse 201 having a pulse width tg for assisting the driving of the step motor by the starting pulse E (Hereinafter, unless otherwise specified, the starting pulse E includes the auxiliary starting pulse)
Is output to the drive circuit 110 td after the falling of the phase matching pulse C by the start pulse generation signal O. The differential amplifier output F of the differential amplifier 108 connected to the counter electromotive voltage detection coil 306 is shown in FIG. Spike noise 202 (hereinafter referred to as noise corresponding to the trailing edge of the subsequent drive pulse H unless otherwise specified) is superimposed on the differential amplifier output F. By inputting 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 is
Since it has a function of digitally masking the spike pulse 204 corresponding to the spike noise 202 shown in FIG. 5, the subsequent drive pulse generation means 114 is after the input of the subsequent drive pulse generation signal from the start pulse generation means 113. 2 (g) corresponding to the zero cross 203 shown in FIG. 2 (f), the rising and falling times of the spike pulse 204 are excluded from the rising and falling times of the zero cross comparator output G shown in FIG. 2 (g). In synchronization with the time, as shown in FIG. 2 (h), a pulse width (narrower than the phase matching pulse width (tc) and the starting pulse width (te) corresponding to the battery voltage detected by the battery voltage detection circuit 111 ( The subsequent drive pulse H of (tah) is output. The step motor 301 drives the subsequent drive pulse H
As a result, the rotor 303 can be rotated at a high speed at a rotational speed that is balanced with the frictional resistance acting on the rotor 303 that is constantly accelerated.

Here, the subsequent drive pulse generating means 11
4 narrows the pulse width (tah) of the subsequent drive pulse H as the rotation speed of the step motor increases, so that the pulse width (tah) is optimal for the rotation speed of the step motor. In this embodiment, since the differential amplifier 108 shown in FIG. 4A does not have a lowpass filter, a lowpass filter composed of a resistor R1 and a capacitor C1 shown in FIG. 4B (hereinafter referred to as R1C1 lowpass filter). Therefore, the rotation angle θ corresponding to the rising and falling of the zero-crossing comparator output G excluding the spike pulse 204 is approximately −θ0 or π−θ
It becomes 0. Compared to when there is a low-pass filter consisting of R1C1, sufficient acceleration can be performed before braking against rotation of the rotor of the step motor due to detent torque (braking when θ = 0 to π / 2 or π to 3π / 2). The number of rotations of the rotor can be increased.

The block diagram of the circuit for digitally masking spike pulses shown in FIG. 5 will be described with reference to the functional flowchart of the circuit for digitally masking spike pulses shown in FIG. The starting pulse composed of the phase matching pulse and the starting pulse is independently output to the zero-cross comparator output G from the phase matching pulse generating means and the starting pulse generating means, respectively. Therefore, in FIG. The following drive pulse of is shown. Further, the spike pulse 204 may not be generated when the rotation speed of the step motor increases, so that the spike pulse 204 in FIG.
Shows the zero-cross comparator output G in which the spike pulse 204 is generated and the zero-cross comparator output G in which the spike pulse 204 is not generated. Figure 5
Block the inversion of the zero-cross comparator output G generated by the starting pulse E with respect to the zero-cross comparator output G (here, the starting pulse E is the starting pulse E excluding the auxiliary starting pulse) Block 1, spike pulse Block 2 for masking back edge 602 of 204, front edge 601 of spike pulse 204, and block 3 for corresponding to zero-cross comparator output G in which spike pulse 204 is not generated. There is. First, in block 1, the zero-crossing comparator output G is input to a waveform shaping circuit that makes the rising and falling edges of the pulse of the zero-crossing comparator output G multiple rising and falling into a single rising and falling, and the waveform is shaped. By taking the OR with the starting pulse E, the inversion of the zero-cross comparator output G occurring before the ending of the starting pulse E is avoided.

In block 2, in order to mask the back edge 602 of the spike pulse 204, the zero cross comparator output G is first passed through the delay circuit 501,
Outputs F3Q (d) and F3 of the flip-flops F3 and F4 according to inverted and non-inverted inputs of the output of the delay circuit 501.
4Q (e) is generated, and then F3Q is calculated by AND and A1.
An AND output of (d) and F4Q (e), A1 (f) is generated. Here, the whisker pulse output M2Q (g) of the pulse generator M2 due to the rising of the subsequent drive pulse H (a).
As a result, the flip-flops F3 and F4 are reset. In the block 3, the outputs F1Q (j) and F2Q (k) of the flip-flops F1 and F2 are generated by inputs of the inverted (c) and non-inverted (b) of the zero-cross comparator output G, and the F1Q (j) and F2Q ( OR output Q2 of k)
(L) is output to generate the subsequent drive pulse H. Here, in order to mask the spike pulse 204, a pulse generator M by the trailing edge of the subsequent drive pulse H (a) for masking the front edge 601 is provided.
1 output pulse M1Q (h) and the back edge 602
The flip-flops F1 and F2 are reset by the OR output Q1 (i) of A1 (f) for masking.

An embodiment using the tapped coil will be described below. FIG. 11A is a plan view of a vibration alarm driving step motor in the tapped coil, FIG.
11B is a sectional view taken along the line CC ′ of FIG. 11A, the plan view of the stator and the rotor is the same as FIG. 3C, and the step motor 1101 is the rotor 3 provided with the eccentric weight 302.
03, a stator 304, and a drive coil 1102. As shown in FIG. 9, the counter electromotive voltage detection coil 11
Reference numeral 03 denotes a coil which is formed of the entire drive coil 1102 or a tap of which is taken out from a part thereof.

The counter electromotive voltage generated in the counter electromotive voltage detection coil 1103 will be described. The counter electromotive voltage Vb generated in the counter electromotive voltage detection coil is obtained by the following formula 3 including the voltage drop Rb · ib due to the DC resistance Rb of the counter electromotive voltage detection coil, where ib is the current flowing in the counter electromotive voltage detection coil. To be

[Equation 3]

In equation 3, -Lb · (di _b / dt)
Is the equivalent self-inductance Lb of the back electromotive force detection coil 1103 (the number of turns of the back electromotive force 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 the sign of the product of the time change of the drive current i _b and the magnetic resistance of the magnetic circuit of the step motor, and is generated by the time change of the drive current i _b.
sin (θ + θ ₀ ) · (dθ / dt) is the mechanical coupling coefficient Kb with the step motor 1101, sin (θ + θ ₀ ) 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, It is generated by the rotation of the rotor 303. θ ₀ is the initial angle of the rotor 303, and in the plan view of the stator and rotor shown in FIG. 3C, from the magnetic pole N (S) position of the rotor permanent magnet 308 of the rotor 303 stationary by the detent torque to the stator 304.
The angle from the slit 309 to the position of approximately 90 degrees.

Further, the output Vgb of the differential amplifier described later
Is calculated by the following equation 4.

[Equation 4]

Vgb of the equation 4 is the differential amplification force F of the differential amplifier 908 in the block diagram of the high-speed rotation drive circuit of the rotor of the step motor shown in FIG.
By _{b · sin (θ + θ 0} ) · (dθ / dt) to detect when it becomes zero, shown in FIG. 3 (c), the magnetic poles of the rotor permanent magnets 308 of the rotor 303 stationary by the detent torque N (S) The rotor 303 from a position
Of the rotation angle _{θ (-θ0, -θ 0 + π} ) will be able to detect. Here, Gb is the gain of the differential amplifier 908.
The output Vgb of the differential amplifier in the tapped coil is
Compared with the output V of the adder in the cancel type coil described later, it depends on the time change of the drive current ib of the drive coil.
Gb · Lb · (di _b / dt) −Rb · i _b is entered,
It can be ignored.

The configuration of the block diagram of the embodiment of the high-speed rotation drive circuit for the rotor of the step motor having the tapped coil shown in FIG. 9 will be described. FIG. 9 is a block diagram of an embodiment of a high-speed rotation drive circuit for 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 of No. 08 and the differential amplifier 108, differently, the drive coil 1102 of FIG. 9 is connected to the drive circuit 110, and the counter electromotive voltage detection coil 1103 is connected to the differential amplifier 9 of FIG.
It is connected to 08. Hereafter, since it is similar to FIG. 1, the description is omitted.

FIG. 10 is 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 for driving the rotor of a step motor having a tapped coil at high speed. It will be described with reference to the drawing. In FIG. 10, (a) to (e) are the same as those in FIG. The differential amplifier 90 connected to the counter electromotive voltage detection coil 1103.
The differential amplifier output F of No. 8 is shown in FIG. Spike noise 1002 is superimposed on the differential amplifier output F. By the input of the differential amplifier output F, the zero-cross comparator 107 outputs the zero-cross comparator output G to the subsequent drive pulse generating means 114 as shown in FIG. Zero cross comparator output G
The spike pulse 1004 corresponding to the spike noise 1002 is superposed on. However, the subsequent drive pulse generating means 114 is configured so that the spike noise 10 shown in FIG.
02 has a function of digitally masking the spike pulse 1004 corresponding to 02, so that the subsequent drive pulse generation means 114 receives the subsequent drive pulse generation signal J from the start pulse generation means 113, and then FIG. Corresponding to the zero-cross 1003 shown in FIG. 10, in the rising and falling times of the zero-cross comparator output G shown in FIG. 1
As shown in 0 (h), a pulse width (t) narrower than the phase matching pulse width (tc) and the starting pulse width (te) corresponding to the battery voltage detected by the battery voltage detection circuit 111.
The subsequent drive pulse H of bh) is output. The step motor 301 is constantly accelerated by the subsequent drive pulse H, and can rotate the rotor 303 at a high speed at a rotational speed that is balanced with the frictional resistance acting on the rotor 303. Here, the subsequent drive pulse generation means 114 narrows the pulse width (tbh) of the subsequent drive pulse H as the rotation speed of the step motor increases, and makes the pulse width (tbh) optimal for the rotation speed of the step motor. . This embodiment is shown in FIG.
The differential amplifier 908 shown in FIG. 12A has the R shown in FIG.
By not having a 2C2, R3C3 low-pass filter, the differential amplifier 9 according to the low-pass filter
Since the output F of 08 is not delayed in time, the rotation angle θ corresponding to the rising and falling of the output of the zero-cross comparator excluding the spike pulse 1004.
Is approximately −θ ₀ or π−θ ₀ . Compared to when there is a low-pass filter, braking (θ = 0 to the rotation of the step motor rotor due to detent torque)
(Brake is applied when π / 2 or π-3π / 2)
Before it takes a lot of time, it can be accelerated sufficiently and the number of rotations of the rotor can be increased.

Next, an embodiment using a cancel type coil will be described. FIG. 15A is a plan view of a vibration alarm driving step motor in the cancel type coil, FIG.
5 (b) is a sectional view taken along the line CC ′ of FIG. 15 (a), and FIG. 3 (c).
Is a plan view of a stator and a rotor, and a step motor 30
1 comprises a rotor 303 provided with an eccentric weight 302, a stator 304, and a drive coil 1502. The drive coil 1502 is connected in series to the actual drive coil 1503 and the active drive coil in order to detect the magnetic pole position of the rotor 303, and two rotor generation reverses having the same DC resistance and self-inductance but different winding directions. Electromotive voltage detection coil C1504, rotor generated counter electromotive voltage detection coil D150
It is composed of 5.

The rotor-generated back electromotive force detection coils C and D
The counter electromotive voltage generated in the circuit will be described. The counter electromotive voltage Vc generated in the rotor-generated counter electromotive voltage detection coil _C , including the voltage drop Rc · i _C due to the DC resistance Rc of the rotor-generated counter electromotive voltage detection coil C, is calculated by the following equation 5.

[Equation 5]

In Equation 5, -Lc · (di _C / dt)
Is the equivalent self-inductance Lc of the rotor-generated back electromotive force detection coil C1504 (where the number of turns of the actual drive coil and the rotor-generated back electromotive force detection coil C is n _0c , n _c , the equivalent self-inductance Lc is Lc = n _0c · n _c / Rm: where Rm is the sign of the product of the time change of the drive current i _C and the magnetic resistance of the magnetic circuit of the step motor, and is generated by the time change of the drive current i _C. s
in (θ + θ ₀ ) · (dθ / dt) is the step motor 3
01 is a product of the mechanical coupling coefficient K, sin (θ + θ ₀ ) and the rotational angle θ of the rotor 303, that is, the product of the angular velocity, with the opposite sign, and is generated by the rotation of the rotor 303. θ ₀ is the initial angle of the rotor 303, which is shown in FIG.
In the plan view of the stator and rotor shown in (c), the angle is from the magnetic pole N (S) position of the rotor permanent magnet 308 of the rotor 303 stationary by the detent torque to the position of approximately 90 degrees from the slit 309 of the stator 304.

Further, the rotor-generated back electromotive force detection coil D1
The counter electromotive voltage Vd generated at 505 is a voltage drop Rd · id due to the DC resistance Rd of the rotor generated counter electromotive voltage detection coil D.
Including the above, it is calculated by the following equation 6.

[Equation 6]

Similarly, Vd of the equation 6 is -Ld. (Di _d / d
t), - Kd · sin ( θ + θ 0) · (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,
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 is different due to the different direction of the drive current i.

Further, the output V of the adder, which will be described later, is obtained by the following equation 7.

[Equation 7]

V in the equation (7) is the addition output F'of the adder 1308 in the block diagram of the high-speed rotation drive circuit of the rotor of the step motor shown in FIG. 13 which will be described later. As a result of adding Vc and Vd, the voltage due to the DC resistance is obtained. The drop is canceled and the driving current i changes with time to −2 · G · L · (d
i / dt) and the counter electromotive voltage generated by the rotation of the rotor 303, −2 · G · K · sin (θ + θ ₀ ) ·
It is the sum of (dθ / dt). The-2.G.K.sin
By detecting the time when (θ + θ ₀ ) · (dθ / dt) becomes zero, the position from the magnetic pole N (S) position of the rotor permanent magnet 305 of the rotor 303 stationary by the detent torque shown in FIG. 3C is detected. Rotation angle θ of the rotor 303
(−θ ₀ , −θ ₀ + π) can be detected. Here, G is the gain of the adder 1308. It should be noted that −2 · G · L · (di / dt) in the equation 7 has a negligible value and does not affect the detection. Since the rotor-generated back electromotive force detection coils C and D have different directions of the drive current i from each other, they do not contribute to the rotational drive of the rotor 303 and the power is invalidly consumed by the Joule loss of the DC resistances Rc and Rd. Even if the number of turns of each of the rotor-generated back electromotive force detection coils C and D is about 1/40 of that of the drive coil 101, the output from the adder 1308 is at a level at which the zero-cross comparator 107 shown in FIG. Therefore, the reactive power consumption of the rotor-generated back electromotive force detection coils C1504 and D1505 can be ignored compared to the power consumption of the drive coil 1502.

An explanatory view of an embodiment for driving the rotor of a step motor having a cancel coil shown in FIG. 14 at a high speed is shown in FIG. 13, and an embodiment of a high speed rotation driving circuit for a rotor of a step motor having a cancel coil is shown in FIG. This will be described with reference to the block diagram of FIG. In this embodiment, the starting pulse generating means 113 generates a pulse composed of the starting pulse E and the auxiliary starting pulse 201, and the adder 1308 shown in FIG. 16 is an R3C shown in FIG. 19 described later.
3, without R4C4, R5C5 low pass filter,
On the other hand, the subsequent drive pulse generating means 114 is generated by spike noise superimposed on the counter electromotive voltage added by the adder, as described in detail in the configuration diagram of the circuit for digitally masking spike pulses in FIG. It also has a function of digitally masking the spike pulse, and 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 subsequent drive pulse width (th) as the rotation speed of the step motor increases. Have.

The process up to the generation of the starting pulse E is the same as that shown in FIG. The adder 13 connected to the rotor-generated back electromotive force detection coils C1504 and D1505
The adder output F ′ of 08 is shown in FIG. Spike noise 1402 is superimposed on the adder output F ′.
By the input of the adder output F ′, the zero-cross comparator 107 outputs the zero-cross comparator output G as shown in FIG.
Output to. The zero cross comparator output G has a spike pulse 1 corresponding to the spike noise 1402.
404 is 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 outputs the subsequent drive pulse generation signal from the start pulse generation means 113. After the input of J, the spike pulse 1404 rises and falls 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. 14F. In synchronization with the time excluding the time, as shown in FIG. 14 (h), it corresponds to the battery voltage detected by the battery voltage detection circuit 111,
Phase matching pulse width (tc) and starting pulse width (te)
The subsequent drive pulse H having a narrower pulse width (th) is output.

The step motor 301 is constantly accelerated by the subsequent drive pulse H and can rotate the rotor 303 at a high speed at a rotational speed that is balanced with the frictional resistance acting on the rotor 303. Here, the subsequent drive pulse generating means 114 has a pulse width (t
h) is narrowed as the rotation speed of the step motor increases,
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 R3C3, R4C4, and R5C5 low-pass filters shown in FIG. 19, which will be described later, the output F of the adder 1308 due to the low-pass filter is not delayed, so that the zero crossing is performed. The rotation angle θ corresponding to the rising and falling of the comparator output is approximately −θ0 or π−
becomes θ0. Brake (θ = 0 to π / 2 or π to 3) against rotation of the rotor of the step motor due to detent torque, as compared with the case where the low-pass filter is provided.
Before the braking is applied at π / 2), sufficient acceleration can be performed and the rotation speed of the rotor can be increased. In this embodiment, under the condition that the voltage applied to the driver of the step motor is 3 V and the pulse width of the subsequent drive pulse is about 3 ms, the rotation speed of the rotor 303 per minute is about 6000 rp.
m, 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. 17 (e) of the explanatory view of the embodiment for driving the rotor of the step motor shown in FIG. 17 to rotate at high speed is the same as FIG. 14 and its explanation is omitted. FIG. 18 shows a circuit configuration diagram of the adder 1708. The adder 1708 includes a rotor-generated back electromotive voltage detection coil C1504 and a rotor-generated back electromotive voltage detection coil D.
Differential amplifier 1601 and differential amplifier 1 connected to 1505
602 and R4C4, R5C5 low-pass filters connected to the respective output terminals of the differential amplifiers 1601, 1602 and R3 / R6 or R3 / R7 amplification degrees of R3 / R6 or R3 / R7 connected to the R4C4, R5C5 low-pass filters,
It is composed of a summing amplifier 1903 having a low-pass filter formed by C3. The adder 1708
Is also expressed by Equation 9 (the gain G has a frequency characteristic by a low-pass filter), but in reality, the outputs corresponding to the generation time of the subsequent drive pulse H of the differential amplifiers 1601 and 1602 are the same. Since it becomes a code and cannot be removed by the adding amplifier 1903, it appears as so-called spike noise overlapping with the adding output F ′. Here, the spike noise refers to not only noise corresponding to the trailing edge of the subsequent drive pulse H but also noise corresponding to the trailing edge to the trailing edge of the subsequent drive pulse H. If the spiked noise causes the addition output F ′ to cross zero at an arbitrary time, an unnecessary subsequent drive pulse H is output from the drive pulse generation microcomputer 1709, and the rotor 303 cannot rotate normally. Therefore, in order to remove the spike noise, R4C4, R4
A 5C5 lowpass filter and a lowpass filter formed by R3 and C3 are required.

The cutoff frequency of the R3C3 low-pass filter is calculated by the equation (8).

[Equation 8]

The cutoff frequency of the R4C4 low pass filter is calculated by the equation (9).

[Equation 9]

The cut-off frequency of the low-pass filter formed by R5 and C5 is calculated by the equation 10.

[Equation 10] In order to remove the spike noise, the f1, f
It is necessary to set 2 and f3 in the range from fr to 4fr, where fr is the maximum rotation frequency of the step motor. Of the spike noises, the low-pass filter can remove high-frequency spike noises corresponding to rising and falling of the subsequent drive pulse H, but removes spike noises of frequencies lower than the cutoff frequencies f1, f2, and f3. Since it cannot be performed, the phase matching pulse C, the starting pulse E, and the subsequent drive pulse H are generated within the generation time of FIG.
A clamp 1802 is generated at the adder output F shown in (f). However, the zero-cross comparator 10 by the spike pulse corresponding to the trailing edge of the subsequent drive pulse H
Since the zero cross output of 7 is eliminated and the subsequent drive pulse H can be generated only by the zero cross of the rotor-generated back electromotive force,
There is no problem in the stability of high-speed rotation of the step motor.

The low-pass filter causes a time delay in the addition output F ′, and the rotation angle θ corresponding to the rising and falling of the zero-crossing comparator output G deviates from −θ ₀ or π−θ ₀ . The rotation angle θ
Effectively utilizes the detent torque and the exciting torque generated by the drive current flowing through the drive coil 1502 for the rotational drive of the rotor 303, and in order to optimize the starting characteristic and the rotational speed of the rotor 303, corresponds to the detent torque. It is desirable to be located between the magnetic equilibrium point and the excitation equilibrium point corresponding to the excitation torque, and as shown in FIG.
theta _0, or it is desirable that the [pi-theta ₀ to [pi.
When the delay of the rotation angle θ becomes larger than θ ₀ ,
As shown in FIG. 9 (f) (FIGS. 19 (a) to 19 (e) are the same as FIG. 18, the description thereof will be omitted.), So that the zero-cross level of the zero-cross comparator 107 shown in FIG. 17 is shifted from the zero level to the plus side. (Zero cross level 20
01), shift to the negative side (zero cross level 200
2) by setting, the zero-cross comparator 107 is operated in the time advancing direction, and FIG.
As shown in (g), the rise and fall of the zero-cross comparator output G are advanced in time, and FIG.
As shown in, the generation of the subsequent drive pulse H must be advanced in time to recover the delay of the rotation angle θ of the rotor 303.

Next, another embodiment of the high-speed rotation drive circuit for the rotor of the step motor having the cancellation type coil will be described based on the configuration of the block diagram of FIG. 20, a configuration different from that of FIG. 13 is that the rotation and non-rotation of the rotor 303 due to the driving of the phase matching pulse C added to FIG. The rotation / non-rotation detecting circuit 2117 outputs the pulse to the pulse generating means 2113. Hereinafter, since the configuration is the same as that of FIG. 13, the description is omitted.

FIG. 21 is an explanatory view of another embodiment for driving the rotor of the step motor having the cancellation type coil at high speed, and FIG. 20 shows a high speed rotation drive circuit of the rotor of the step motor having the cancellation type coil. A description will be given with reference to a block diagram of another embodiment, except that the starting pulse generating means 2113 corresponds to the battery voltage detected by the battery voltage detecting circuit 111 by the starting pulse width signal L, and In response to the rotation / non-rotation signal P of the rotation / non-rotation detection circuit 2117, a start pulse (pulse width: ter when the rotor 303 rotates, ten when the rotor does not rotate) and an auxiliary start pulse (pulse width: rotor 303: (Tgr when rotating, tgn when not rotating)
As shown in FIG. 21 (e) ((f) shown below,
(G) and (h) are also indicated by a solid line when the rotor 303 rotates and a broken line when the rotor 303 does not rotate).
Output to the drive circuit 110 after dr (when the rotor 303 rotates) or tdn (when the rotor 303 does not rotate). In this embodiment of the high-speed rotation drive circuit for the rotor of the step motor, the rotation non-rotation detection circuit 2117 is added to the embodiment of the high-speed rotation drive circuit for the rotor shown in FIG. Corresponding to not only the detected battery voltage but also the rotation and non-rotation of the rotor 303 by the driving of the phase matching pulse C,
The output time and pulse width of the starting pulse E output from the starting pulse generating means 2113 can be set, but in order for the rotation / non-rotation detecting circuit 2117 to detect the rotation / non-rotation of the rotor 303, the phase matching pulse is used. Since a predetermined time is required from the fall of C, even if the rotor 303 is rotated by the phase matching pulse C, the starting pulse E having a wider pulse width than the subsequent drive pulse H is necessary.

The rotor-generated back electromotive force detection coils C and D
21 shows the addition output F ′ of the adder 108 connected to FIG.
It shows in (f). The zero-cross comparator 107 outputs the zero-cross comparator output G to the subsequent drive pulse generating means 114 as shown in FIG. The subsequent drive pulse generation means 114, after the input of the subsequent drive pulse generation signal J from the start pulse generation means 2113, rises and falls times of the zero cross comparator output G corresponding to the zero cross 2203 shown in FIG. 21h, the phase adjustment pulse width (tc) and the starting pulse width corresponding to the battery voltage detected by the battery voltage detection circuit 111 by the subsequent pulse width signal M, as shown in FIG. A subsequent drive pulse having a pulse width (th) narrower than (ter, ten) is output. The stepping motor 301 is constantly driven by the subsequent driving pulse H to accelerate the rotor 30.
Rotor 30 at a rotational speed that is balanced with the frictional resistance acting on 3
3 can be rotated at high speed.

Next, a method of winding the drive coil in the cancel type coil shown in FIG. 22 will be described. Working drive coil 1503, rotor-generated back electromotive force detection coil C15
04, D1505 composed of a drive coil 1502
22 is drawn out from the wire guide 2307 by a wire 2306 shown in FIG. 22, the wire 2306 is hooked on the coil winding frame 2305, first, the rotor generated back electromotive force detection coil D1505 is wound around the coil core 307, and then, The wire 2306 with the wire hooking pin 2
The wire 2306 is hooked on the coil winding frame 2305 by being hooked on the coil 308, the rotor-generated back electromotive voltage detection coil C1504 is wound around the coil core 307 in the opposite direction to the rotor-generated back electromotive voltage detection coil D1505, and the wire 2306 is wound by the wire hooking pin. 2308,
The wire 2306 is hooked on the coil winding frame 2305 by the above, and the actual drive coil 1503 is wound around the coil core 307 in the opposite direction to the rotor-generated back electromotive force detection coil D1505.
Therefore, the wire 2306 is hooked on the wire guide 2307. The two coil terminals of the rotor-generated back electromotive force detection coil C1505 are respectively connected to the coil terminals 1, 2301, and coil terminals 4 and 2304, and the two coil terminals of the rotor-generated back electromotive voltage detection coil C1504 are connected to the coil terminals 2, 2302, respectively. , The coil terminals 4 and 2304 are pressed with the two coil ends of the actual drive coil 1503 to the coil terminals 2 and 2302 and the coil terminals 3 and 2303, respectively. The automatic winding of the coil 1502 around the coil core 307 is completed.

Next, an embodiment of 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 the same as that of the vibration alarm set / reset circuit 105 shown in FIG.
In response to the input of the vibration alarm generation pulse A, the drive on / off signal B including a train of pulses having 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 rotationally driven within the drive on time ton and stopped at the drive off time toff. As a result, the vibration of the vibration alarm is modulated, and the vibration of the eccentric weight of the step motor can be transmitted more strongly to the tactile organs of the arm via the watch case, compared to the constant vibration without modulation. it can.

Next, a second embodiment of the vibration modulation of the vibration alarm shown in FIG. 24 will be described. 1, FIG. 9, FIG. 13, and FIG.
7, the drive on / off generation circuit 106 in FIG.
FIG. 24 from the vibration alarm set / reset circuit 105.
By inputting the vibration alarm generation pulse A shown in (a), the drive on / off signal B composed of a pulse of the drive on time ton corresponding to the drive on of the step motor is output. As shown in FIG. 24C, the subsequent drive pulse generation means generates a subsequent drive pulse having a constant pulse width (th) for the time tcon, and thereafter gradually reduces the subsequent drive pulse width. The subsequent drive pulse interval is measured, and when the subsequent drive pulse interval reaches ts, the subsequent drive pulse width is gradually increased. 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 number of rotations of the step motor rotor increases or decreases, and the vibration of the vibration alarm is modulated. The vibration of the eccentric weight can be more strongly transmitted to the tactile organs of the arm.

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

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

[Equation 11]

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

[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 ₀ is the initial angle of the rotor, Ts is the maximum detent torque, _TL is the load torque, and Mg is the eccentricity. The maximum gravity moment of the weight, L is the self-inductance of the drive coil, R is the DC resistance of the drive coil, u (t) is the unit function of time t, τ is the drive pulse width, V is the voltage applied to the motor driver, and R ₀ (I, V)
Is the ON resistance of the motor driver.

The initial angle of the rotor is θ ₀ (π / 4 = 0.
785 rad), the rotor-generated back electromotive force, -K · s
In (θ + θ ₀ ) · (dθ / dt) becomes zero, the rotor rotation angle θ (−θ ₀ , −θ ₀ + π) or the subsequent drive pulse (pulse width τ) at the time FIG. 25 shows the calculation result (change in the number of revolutions of the rotor per minute with time). Incidentally, for each parameter value, the applied voltage is 3.0 as shown in FIG.
(V), the drive coil DC resistance (R + R ₀ ) including the ON resistance of the motor driver is 200 (Ω), the self-inductance L is 200 mH, and the moment of inertia J is 2.8 × 10.
^-9 (kgm ² ), fluid resistance coefficient r is 16.0 × 10 ^-11
(Nms / rad), electromechanical coupling coefficient K is 5.3 × 1
0 ^-3 (Nm / A), detent torque Ts is 5.3 × 1
0 ⁻⁵ (Nm), load torque T _L is 0.0 (Nm), moment Mg due to gravity of the eccentric weight is 6.0 × 10 ⁻⁶ (N
m). Rotor initial stop angle position θ, -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.
When the number of subsequent drive pulses of ms is 114, the maximum number of rotations is 70 in the change with time of the number of rotations of the rotor per minute.
The stop time of the rotor was about 0.15 s after the completion of the subsequent drive pulse (about 0.55 s) at 00 rpm. The drive current was 15 mA at startup and about 3 mA at constant high speed after 0.5 s. According to this simulation calculation of the number of revolutions of the rotor, the number of revolutions of the rotor is detected by detecting the position of the rotor from the counter electromotive force generated by the rotor, and a drive current is passed through the drive coil in synchronization with the time when the position of the rotor is detected. Depending on the method of accelerating the rotor, 3000 rp
It turns out that it will be over m. It was also found that the drive current (peak value) during constant high speed rotation can be reduced to about 3 mA.

Next, a stator that can be used in the present invention will be described. Although the flat two-pole stator having the slit 261 and the step 262 shown in FIG. 26 (a) has been described in the above embodiment, the present invention is not limited to this and is shown in FIG. 26 (b). Notch 2 with no such steps
A flat two-pole stator having 63, a flat two-pole stator having only slits as shown in FIG.
It can also be realized by using a flat two-pole stator having neither slits nor steps as shown in FIG. Flat 2 in FIG. 26 (d)
The pole stator can be driven by preparing a plurality of starting pulses having different pulse widths and selectively outputting the optimum starting pulse.

[0054]

As shown by the above detailed description, the present invention has low power consumption and durability, is easy to assemble, has a stable start-up and a high-speed rotating step motor, and is reliable. There is an effect that it is possible to provide a small electronic device with a vibration alarm. In particular, it is provided with magnetic pole position detection means for detecting the magnetic pole position of the rotor which is rotating with respect to the flat stator, based on the counter electromotive voltage generated in the counter electromotive voltage detection coil. Since the output timing of the pulse signal is controlled based on the detection signal, it is possible to realize a step motor rotating at a high speed necessary for a vibration alarm.

[Brief description of drawings]

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

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

FIG. 3 is a plan view of a vibration alarm driving step motor having a separated 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 spike pulses.

FIG. 7 is a plan view of a wristwatch with a vibration alarm having a built-in 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 for a rotor of a step motor having a coil with taps.

FIG. 10 is an explanatory diagram for driving a rotor of a step motor having a coil with taps 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 coil with taps.

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

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

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

FIG. 19 is an explanatory diagram for regaining the time delay of the 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 diagram of another embodiment for driving the rotor of the step motor having the cancel coil to rotate at 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 example of vibration modulation of a vibration alarm.

FIG. 25 is a simulation calculation result of a time change of 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.

[Simple 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 actual drive coil 306 1103 back electromotive force detection coil 1504 rotor generated back electromotive voltage detection coil C 1505 rotor generated back electromotive voltage detection coil D

Claims (19)

[Claims] 1. An electronic device with a vibration alarm that drives a motor to rotate an eccentric weight at an alarm time and transmits vibration of the eccentric weight to a wrist via a case body. A step motor comprising a rotor having a magnet and a drive coil magnetically coupled to the flat stator; drive pulse generating means for outputting a pulse signal for driving the step motor based on an alarm signal; A drive circuit for supplying a drive current to the drive coil based on a pulse signal from the drive pulse generating means, the flat stator for transmitting the magnetomotive force generated in the drive coil to the rotor, and the rotation of the rotor A counter electromotive voltage detection coil for detecting a counter electromotive voltage, and the flat stay based on the counter electromotive voltage generated in the counter electromotive voltage detection coil. Magnetic pole position detecting means for detecting the magnetic pole position of the rotating rotor with respect to the rotor, and the drive pulse generating means controls the output timing of the pulse signal based on the detection signal from the magnetic pole position detecting means. An electronic device with a vibration alarm characterized in that 2. The magnetic pole position detecting means has a zero-cross comparator which detects that the back electromotive voltage generated in the back electromotive voltage detection coil has reached zero level and outputs a detection signal. Electronic device with vibration alarm described. 3. The pulse signal from the drive pulse generating means has a start pulse for rotationally starting the rotor in a stopped state and a subsequent drive pulse for continuously driving the rotor after the start. The electronic device with a vibration alarm according to claim 1. 4. A start pulse for rotatably starting a rotor in a stopped state is output after a phase matching pulse for matching the magnetic poles of the rotor facing the magnetic poles of the flat stator to the same polarity, and after the phase matching pulse. 4. The electronic device with a vibration alarm according to claim 3, wherein the flat stator facing the magnetic pole of the rotor comprises a start pulse for generating a magnetic pole having the same polarity as the magnetic pole of the rotor magnet. 5. The electronic device with a vibration alarm according to claim 4, wherein the starting pulse has a wider pulse width than the subsequent driving pulse. 6. The electronic device with a vibration alarm according to claim 5, wherein the starting pulse is a plurality of pulse trains having a wider pulse width than the subsequent drive pulse. 7. The plurality of pulse trains have a first start pulse having a wider pulse width than the subsequent drive pulse, a wider pulse width than the subsequent drive pulse, and a narrower pulse width than the first start pulse. 7. The electronic device with a vibration alarm according to claim 6, wherein the electronic device is equipped with a second starting pulse. 8. The electronic device with a vibration alarm according to claim 3, wherein the pulse width of the subsequent drive pulse is narrowed as the rotation speed of the rotor is increased. 9. The electronic device with a vibration alarm according to claim 1, wherein the back electromotive force detection coil is independently wound around the inner circumference of the drive coil. 10. The electronic device with a vibration alarm according to claim 1, wherein the drive coil also serves as a counter electromotive voltage detection coil. 11. The electronic device with a vibration alarm according to claim 10, wherein a tap is taken out from a part of the drive coil so that part of the drive coil also serves as a counter electromotive voltage detection coil. 12. The magnetic pole position detection means includes a differential amplifier that differentially amplifies a counter electromotive voltage generated in a counter electromotive voltage detection coil, and the counter electromotive voltage differentially amplified by the differential amplifier is at a zero level. 11. The electronic device with a vibration alarm according to claim 9 or 10, further comprising a zero-crossing comparator that detects when it has reached and outputs a detection signal. 13. The back electromotive force detection coil is composed of two back electromotive force detection coils which have substantially the same DC resistance and self-inductance and different winding directions, and are connected in series to a drive coil. The electronic device with a vibration alarm according to claim 1, wherein the electronic device has a vibration alarm. 14. The magnetic pole position detecting means includes an adder for adding the counter electromotive voltages generated in the two counter electromotive voltage detecting coils, and the counter electromotive voltage added by the adder has reached zero level. 14. The electronic device with a vibration alarm according to claim 13, further comprising: a zero-cross comparator that detects a signal and outputs the detection signal. 15. The electronic device with a vibration alarm according to claim 13, wherein the back electromotive force detection coil is formed by winding a plurality of layers on the inner peripheral side of the drive coil. 16. The electronic device with a vibration alarm according to claim 14, wherein the adder has a low-pass filter for cutting spike noise superimposed on the counter electromotive voltage. 17. The drive pulse generating means has a mask means for digitally masking the detection signal from the zero-cross comparator in response to spike noise superimposed on the counter electromotive voltage added by the adder. The electronic device with a vibration alarm according to claim 14. 18. The electronic device with a vibration alarm according to claim 12, wherein the differential amplifier has a low-pass filter for cutting spike noise superimposed on the differential / amplified back electromotive force. 19. The drive pulse generating means is a mask means for digitally masking a detection signal from the zero-cross comparator corresponding to spike noise superimposed on a counter electromotive voltage differentially and amplified by the differential amplifier. 13. The electronic device with a vibration alarm according to claim 12, which has.