JP3057341B2 - Step motor device for electronic watch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention aims at stabilizing the reverse rotation operation when a stepping motor for an electronic timepiece is driven reversely by using a drive circuit which enables normal operation with low power consumption. For improvement.

[0002]

2. Description of the Related Art Conventionally, as a reverse rotation driving device for a step motor for a timepiece, a reverse rotation driving pulse as a set of a plurality of alternating pulses as shown in FIG. Reversing the rotor while catching,
There is known an apparatus in which a high resistance of several tens of kilohms is connected to both ends of a coil after application of a reverse rotation pulse and an induced voltage generated at both ends of the high resistance is detected to detect a rotor operating state at the time of reverse rotation drive. For example, it is disclosed in JP-A-55-33642.

[0003]

However, in the conventional reverse drive device, since the rotation of the rotor is detected after the application of the reverse drive pulse, the time required for the reverse drive per step for the fast forward movement of the motor in the reverse direction is determined. It is a long and disadvantageous detection device. In addition, the conventional rotation detection principle uses a change in an induced voltage generated in a coil due to the damping motion of the rotor after the reverse rotation pulse is applied to the rotor,
This is to detect the rotation state of the rotor. When a load torque applied to a motor increases, a driving device using this conventional detection principle applies a pulse as shown in FIG. 3A and then applies a pulse to the rotor as shown by a solid line in FIG. The damping motion is in a state immediately before the stop compared to the no-load damping motion indicated by the dotted line, and the induced voltage due to the damping motion of the rotor is not generated, which may lead to erroneous detection.

[0004] Further, a P3 pulse that plays a role of braking the damping motion of the rotor to stabilize the reverse rotation drive,
Even when the intermediate power excitation pulse having the divided pulse shape shown in FIG. 4A is applied, the drive device may make an erroneous detection in the same manner as described above. That is, as shown in FIG. 4B, the rotor damping motion when a sufficiently long P3 pulse is applied and when the intermediate power excitation pulse is applied after the P3 pulse are compared with the damping motion in the no-load state shown by the dotted line. , small width of the amplitude, the induced voltage Ri is Do a minute, it is to lead to the detection drive false. Furthermore, when the braking force to the rotor is increased by using a stator having a notch shape having a high magnetic potential energy of the stator hole , the above-described increase of the load torque and the pulse of stopping the damping movement of the rotor are also stopped. As in the case of application or the like, an induced voltage due to the rotor damping motion was not generated, and the drive device sometimes caused erroneous detection.

[0005] The above is a problem of the conventional drive device when detecting the rotational state of the rotor in the reverse rotation drive. Therefore, an object of the present invention is to solve the conventional problems by increasing the load on the rotor over time, or stepping the optimum pulse according to the variation in the production of the motor parts and the change in the power supply voltage. An object of the present invention is to provide a stepping motor that supplies a motor with a stable reverse operation.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to an electronic timepiece having a stepping motor, a wheel train, and a display function, which stores a stepping motor drive signal and a magnetic pole of a rotor. Means, a drive circuit for controlling the drive of the step motor, a detection circuit for detecting the rotation state of the step motor, and a pulse change circuit for changing the drive pulse, and the load on the rotor over time of the step motor The optimum pulse is supplied to the stepping motor in response to the increase in the number of motors, the variation in the shape of the motor parts, the variation in the power supply voltage, etc., so that the reverse operation can be performed with stability, high torque and low current consumption.

[0007]

In the electronic timepiece constructed as described above,
The reverse drive pulse P3 current flowing through the coil during application providing the rotation detection section for sampling detected. Then, the applied pulse is interrupted during the rotation detection section and both ends of the coil are short-circuited, and the gate is intermittently formed to form two states of a closed loop connecting the impedance element and the coil through some gate elements. The switching of the element is performed, and the change of the induced voltage generated at both ends of the impedance element due to the rotation of the rotor is sampled.

[0008] The rotation state of the rotor in the rotation detection section, remote over main <br/> cement by the rotational force is generated, which holds the relatively rotational speed fast rotation state, a reverse rotation pulse is supplied . The induced voltage sampled in the detection section is amplified by switching a switch between a low resistance element and a high resistance element, and becomes a somewhat high voltage against external noise. The detection circuit compares this voltage with a reference voltage formed from the power supply voltage, determines the appropriateness of the rotational state and position of the rotor based on the comparison result, and controls the presence or absence of a change in the reverse rotation pulse to be output thereafter. Is output. When the pulse waveform synthesizing circuit receives the pulse change signal from the detection circuit, the pulse waveform synthesizing circuit changes the application direction and pulse width of the subsequent reverse drive pulse. The drive circuit outputs the reverse drive pulse to the step motor, so that the step motor can perform stable reverse drive with high torque and low current consumption.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an example of an output timing of a reverse rotation pulse and a detection voltage realized by the present invention. FIG. 1 (A)
FIG. 5 is a diagram showing a relationship between a pulse output timing of a reverse rotation pulse of a motor and a detection timing of a detection pulse for determining a rotation state of a rotor (hereinafter, referred to as a detection section).

[0010] In the present invention different from the conventional detection period, the detection zone shorted voltage application state at a plurality of locations of reverse pulse (t1 section and t2 section) is provided, detecting the rotational state of the rotor and outputs a detection pulse I do. Then, the length of the P1 pulse width to be output next is changed according to the detection result (the P1 pulse in the figure is changed to the P1 'pulse in the next reverse drive section), and the reverse rotation matching the rotation state of the rotor is performed. It is also characterized in that a drive pulse is supplied to a motor.

FIG. 1B shows that an induced current generated in a coil in a detection section flows into a high impedance element (for example, a resistance element of several hundred KΩ) by intermittent switching of a MOS gate provided in a detection circuit. FIG. 6 is a diagram illustrating a voltage waveform when a transient voltage is obtained. Since the induced current generated in the coil changes according to the driving condition and the rotation state of the rotor, it is possible to detect the reverse rotation driving state of the motor using this current. Further, since the connection with the high impedance element is not performed except for the detection pulse, no detection voltage is generated. VTH in FIG. 1B is a reference voltage for determining the rotation state. This reference voltage VTH will be described in detail in the circuit of the present invention described later.

Here, the timing for detecting the rotor rotation state during reverse rotation driving will be described. The detection section of the present invention is provided between the P1 pulse and the P2 pulse of the drive pulse (section t1) and between the P2 pulse and the P3 pulse (section t2). In the sections t1 and t2, a section in which the inertial force of the rotor exceeds the magnetomotive force generated by the pulse and does not affect the reverse rotation drive even if no pulse is applied is selected. That is, in the detection section of the present invention, regardless of the presence or absence of the detection section, the state in which the reverse drive of the motor is stable can be maintained.

[0013] Then, the reverse rotation of the present invention, the appropriate reverse pulse obtained by adding the detection section of the conventional reverse pulse, performs reverse drive is supplied to the motor, it determines the rotation state of the rotor during movement drive to the further It has a configuration. Also, the reason why the present invention short-circuited the drive pulse in the detection interval is that the current supplied from the power supply to the motor canceled out the induced current generated by the rotation of the rotor, and it was not possible to detect the original rotor rotation state. To invite.

As described above, by outputting the above-described series of reverse drive pulses and detection pulses in the reverse drive device realized by the present invention, the pulse application section in reverse drive can be shortened. The role of each pulse described in the above is sufficiently fulfilled to eliminate the disadvantage of erroneous detection due to insufficient damping motion of the rotor. Next, before starting a detailed description of the present invention, the operation principle of the reverse rotation drive and the role of each pulse in the reverse rotation drive pulse will be briefly described with reference to FIGS.

FIG. 5 shows the relationship between the reverse rotation pulse, the rotation angle of the motor, and the rotation speed. The P1 pulse in FIG. 5A plays a role of rotating the stationary rotor 1 (at the position of the angle α in FIG. 6) in the forward direction, and the potential energy in the normally rotated direction of rotation is converted into rotational energy by the next P2 pulse. It is converted (point a in FIG. 5B). However, the forward rotation angle by the P1 pulse is limited, and when the rotation angle becomes larger than the angle β in FIG. 6, the magnetic potential energy of the stator 2 reduces the rotation energy of the reverse rotation by the P2 pulse, and the reverse rotation becomes turbulent. Therefore, the P1 pulse has a pulse width such that the rotation angle of the rotor 1 does not exceed the angle β.

The P2 pulse shown in FIG. 5A serves to supply the motor with electromagnetic energy for pulling the rotor 1 back in the direction of the X axis (0 °), and the rotor 1 is driven by the electromagnetic energy and the potential energy described above. It rotates in the opposite direction (point b in FIG. 5B). During the application of the P2 pulse, the rotation speed of the rotor 1 rapidly increases, and its direction becomes the reverse direction (between the point f and the point g in FIG. 5C). And the rotational force of the rotor 1 is also increasing. The P3 pulse shown in FIG. 5A rotates the rotor 1 in the reverse direction by utilizing the rotational force of the rotor 1 in the reverse direction and the magnetic repulsive force by the P2 pulse,
Further, it plays a role of stopping the rotor 1 at the angle γ by magnetic attraction according to the angle of the rotor 1 (d in FIG. 5B).
From point to point e).

As described above, the reverse rotation pulses P1, P2, P
3 have different roles, and the rotational force of the rotor also changes for each pulse. As a condition for detecting the rotation state in such a rotation state of the rotor, the detection is performed at a timing when the rotation force of the motor is high, the rotation speed is high, and the change in the induced voltage is large. Therefore, in the present invention, since the condition between the point g and the point h shown in FIG. 5C in the P3 pulse satisfies the above condition, the rotor rotation detection section is provided between the point g and the point h. By detecting the rotation state of, more accurate rotation detection of the reverse drive is realized.

Next, when the timepiece motor changes from normal forward drive to reverse drive and performs reverse drive, a series of operations performed by the motor drive circuit, the rotation detection circuit, the pulse waveform synthesizing circuit, and the like in the present invention. Will be described with reference to an example of a circuit configuration diagram of the present invention in FIG. In FIG. 7, reference numeral 10 denotes an oscillation circuit, usually 32
A crystal oscillator oscillating at 768 Hz is used. 1
Reference numeral 1 denotes a frequency dividing circuit which divides the frequency by a 15-stage flip-flop and supplies a plurality of timings to a pulse waveform synthesizing circuit 13.

The frequency dividing circuit has a reset input terminal, and when a reset signal is input, all frequency dividing stages are reset. Reference numeral 12 denotes a signal for controlling reverse rotation. When a signal for performing reverse rotation operation is input, it is input to the pulse waveform synthesizing circuit 13 and the reverse pulse width control circuit 17. A pulse waveform synthesizing circuit 13 synthesizes a reverse rotation pulse and a detection pulse for detecting rotation of the reverse rotation according to a pulse forming signal from the reverse rotation pulse width control circuit 17 using a signal of the frequency dividing stage as a reference timing. 14 is a drive inverter M
A driving circuit having an OS gate. The driving gate is turned ON / OFF according to the reverse rotation pulse synthesized by the pulse waveform synthesizing circuit 13, and a driving voltage is applied to the motor 15 to realize the reverse rotation driving of the motor 15. The rotation state of the rotor at the time of the reverse rotation drive of the motor 15 depends on the influence of the applied voltage and the externally applied load torque and the like, and the induced voltage generated in the coil also changes due to the above-described influence. Therefore, the driving voltage during application of the reverse rotation driving pulse differs depending on the driving state of the rotor.

In the present invention, as means for detecting the rotation state of the rotor based on the drive voltage, a rotation detection circuit 16 having a MOS gate, an operational amplifier, a resistor and the like constituting a detection inverter is provided. The detection circuit 16 turns ON / OFF the detection gate in the detection section of the reverse rotation drive pulse.
Then, the drive voltage is detected, the drive voltage is compared with a reference voltage provided separately, the comparison result is changed to a pulse change signal, and the pulse is reset after being output to the reverse rotation pulse width control circuit 17. Reference numeral 17 denotes a control circuit for controlling the pulse width and the number of driving steps of the reverse rotation pulse, and generates a pulse forming signal in accordance with the pulse change signal from the detection circuit 16 and the reverse rotation signal 12.

By performing such a series of electrical operations, the rotor rotation state from the reverse rotation drive is accurately detected,
By supplying an appropriate pulse to the motor, a stable motor reversing operation was realized. Incidentally driving circuit for use in the present invention 14, because it was the rotation detection by the MOS gate and a high impedance element, motor during reverse drive that consumes normal rotation or mass to electric power and require low power consumption
It is now possible to perform the motor drive and rotor rotation detection on the same circuit . Therefore, an example of a simple driving circuit diagram of the present invention will be described with reference to FIG.

The sources and drains of the MOS gates 20, 21, 22, and 23 are VDD and GND as shown in FIG.
The motor 26, the above-mentioned respective MOS gates and the resistors 27 and 28 are connected at the contacts 35 and 36. This circuit controls the direction of the current applied to the motor 26 by turning on and off the above-mentioned MOS gate, and determines the rotation direction of the motor.

The above-described current flows along the paths 31 and 32. The above is a simple circuit description related to motor driving. Next, a brief circuit description related to motor rotation detection will be described. The high resistance elements 27, 28 connected to the contacts 35, 36 at both ends of the motor are connected to the MOS gate 24,
MOS gate 2
Sources 4 and 25 are grounded to GND. In this circuit, when the MOS gates 20 and 22 are OFF, the MOS gates 21 and 23 and the MOS gates 24 and 25 are ON / OFF.
Is performed, the high resistance elements 27, 28
Currents (paths 33, 34), and contacts 37, 38
Is input to the voltage detectors 29 and 30.

Incidentally, as an example of the present invention, the high resistance value is expressed by the following equation (1).
00KΩ is used, and the above-mentioned switch switching is performed from 61 to 2
In the cycle of 44 nsec, the ON / OFF of the above-mentioned gate was performed only once. However, by incorporating a voltage amplifying circuit into the components of the motor or the voltage detector, a resistance element of several tens of ohms can be used, and the resistance value of the gate can be set to ON.
・ It is also possible to turn OFF multiple times.

Next, an example of the reverse rotation operation of the present invention will be described with reference to FIG. Normally, the pulse waveform synthesizing circuit that outputs the normal rotation pulse to the drive circuit is switched to output the reverse rotation drive pulse when the reverse rotation signal is input, and the motor starts the reverse rotation drive. The reverse rotation pulse at the start of reverse rotation drive is
The pulse is set to a certain initial setting pulse, the pulse change signal φ6 is “0”, and the pulse is applied to the motor to perform reverse drive. When the rotation state of the motor is stable, the reverse rotation pulses P1, P2, and P3 are hijacked and output on path 1 in FIG. 9, and after every P2 pulse output, the rotation state of the rotor is detected via path 4 and the next reverse rotation pulse is output. Output.

If the rotation state of the motor changes and the detection circuit determines a pulse change, the pulse change signal φ6 becomes "1" via the path 3. Note that the P3 pulse is output regardless of the determination of the detection circuit. Then, as the P1 pulse of the next reverse rotation pulse, the P1 pulse changed via the path 2 is output to the motor, and the subsequent P2 pulse output, P3 pulse output, and rotation detection are sequentially performed. Then, the motor returns to the normal rotation drive after the completion of the reverse rotation drive.

The above is a description of a series of electrical operations performed by each circuit configured according to the present invention. The above behavior is
The P1 pulse width of the reverse rotation drive pulse is changed in accordance with the variation of the parts constituting the step motor, the change of the power supply voltage, and the change of the rotating state at each time, so that it is always high speed, low current consumption, high torque and stable. Monodea the pulse width, carried out automatically selected and reversely driven by a detection circuit capable to reverse
You .

As described above, the outline of a series of operations on the electric circuit of the present invention and the principle of detecting the rotation of the rotor have been described.
External elements such as mechanical switches and Hall elements are conceivable, but it is difficult to arrange these elements in an extremely small capacity such as an electronic wristwatch. Therefore, the present invention realizes stable reverse rotation drive by having a detection circuit in the same integrated circuit together with the oscillation, frequency division, and drive circuits without the need for external elements, and performing the reverse rotation drive and rotation detection of the feasible rotor. It is an invention.

Next, the relationship between the driving operation voltage range of the motor and the external load torque when the motor is reversely driven using the reverse rotation driving device of the present invention will be described with reference to FIG. The timepiece step motor is composed of three parts, a rotor, a stator and a coil. When a motor is manufactured, it is impossible to manufacture the motor with the same specifications such as the energy product of the rotor, the potential energy of the stator, the electrical resistance and the number of turns of the coils, and the like. Further, since the rotor is meshed with the wheel train by a plurality of gears, the motor is affected by the loss torque (external load torque) by the wheel train other than the rotor. The performance and load torque of such a motor change the drive voltage operating range of the motor.

FIG. 10 shows the relationship between the operating voltage range of the reverse drive and the external load torque when each component is manufactured to a certain specification. The range indicated by oblique lines is data when the P1 pulse in the reverse rotation pulse is made constant, and the range surrounded by a solid line is data when the P1 pulse is varied. There is a clear difference in the drive voltage range between the case where the P1 pulse is varied according to the load torque and the drive voltage and the case where the pulse is fixed. In the present invention, focusing on the above-mentioned contents, the present invention invents a reverse rotation driving device having a method of changing the P1 pulse of the reverse rotation pulse, so that the present invention can be applied to manufacturing variations of any parts and increase / decrease of external load torque. The reverse drive of the motor having a wider drive voltage range has been realized.

Next, an embodiment of the present invention will be described.
FIG. 11 shows an embodiment of the drive circuit and the detection circuit. An input terminal Sx is a reverse signal input terminal, and Sy is a normal signal input terminal, which are connected to the set S input and the reset input R of the RS flip-flop 101, respectively. First, the case of normal rotation will be described. When a reset input is input to the RS flip-flop 101, the RS flip-flop 101
Q 'output becomes "H" (High) and the Q output becomes "L" (Low). When the Q output of the RS flip-flop 101 becomes “L”, the output of the AND gate 102 becomes “L”. P
x, Py, Φ1, Φ2, Φ3, Φ4, Ps1, Ps2,
Ps3 is output at the timing shown in FIG. 12, and the output of the frequency dividing circuit is combined with the pulse shown in FIG. 12 by a NAND gate, a NOR gate, an OR gate, or the like. Regarding the combination of the pulses, since a circuit can be logically easily designed, a circuit diagram is omitted.

The Q ′ output of the RS flip-flop 101 is “H”, and the AND gate 103 and the NOT gate 10
9 is input. The other input of the AND gate 103 is connected to the normal rotation pulse Py. When Py is “H”, the output of the AND gate 103 becomes “H” and the output of the OR gate 104 also becomes “H”. Timing pulse Φ1
Is connected to a 1-second pulse, and its output is "
When the signal goes high, the output of the NOT gate 105 goes low.
And input to the second input of the NOR gate 106.
The first input of the NOR gate 106 is connected to the Q output of the RS flip-flop 101, and its output state is "L" level, so that the output of the NOR gate 106 becomes "H" and the OR gate 107 And input to the clock of the flip-flop 111. Each time "H" is input to the clock input of the flip-flop 111, its output Q, Q 'is inverted, and the direction of the current flowing through the motor 123 is reversed. Accordingly, an inversion pulse having a cycle of one second is applied to the motor 123.

On the other hand, Q of the RS flip-flop 101
The output “L” is input to the AND gate 162, the output of the AND gate 162 becomes “L”, and the output of the AND gate 163 input to the first input becomes “L”.
The signals input to the second inputs of the AND gates 113 and 115 are always "L", and in the case of normal rotation, the Ps1 signal does not affect the driving state of the motor.

Further, the Q ′ output of the RS flip-flop 101 is connected to the AND gate 1 via the NOT gate 109.
10, the first input of the AND gate 110 becomes “L” and the output thereof becomes “L” in the normal rotation, so that the signal controlling the clock of the flip-flop 111 is only Φ1. As described above, when the outputs of the OR gate 104, the flip-flop 111, and the AND gate 163 become “H” or “L”, the MOSFETs 118, 119,
120 and 121 are turned on or off, and the motor 1
Current flows through 23. Then, the motor performs a forward rotation drive every second.

Next, the case of the reverse rotation drive will be described.
When the reverse rotation signal Sx is set and input to the RS flip-flop 101, its output Q becomes "H" and its output Q 'becomes "L". Since the Q 'output “L” is connected to the first input of the AND gate 103, the output of the AND gate 103 becomes “L”. On the other hand, the Q output of the RS flip-flop 101 is connected to the first input of the AND gate 102.

On the other hand, the reverse rotation pulse Px is applied to the NAND gate 1
61, a detection pulse Ps2 (for P1 pulse UP) and a detection pulse Ps3 (P
OR gate 18 to which one pulse DOWN is connected
0 is connected, and the output of the OR gate 180 is “L”.
When the input of Px is “H”, the NAND gate 161
Is "H". The first input of the AND gate 160 is connected to Px, and the second input is connected to the NAND gate 16.
1 output is connected. Since the output of the AND gate 160 is connected to the second input of the AND gate 102, only when the output of the AND gate 160 is "H", A
The output of the ND gate 102 becomes "H". Then, through the OR gate 104, the output of the AND gate 102 becomes NA
The signals are input to the second inputs of the ND gates 112 and 114, respectively.

Next, the Q of the RS flip-flop 101
The output “H” is output to the NOR gate 106 and the AND gate 16
2 is connected to a first input. The output of the NOR gate 106 becomes "L" irrespective of the Φ1 signal, and the output of the flip-flop 111 is not inverted every second.
The output of the AND gate 162 becomes "H" only when Ps1 is "H". Further, when the output of the AND gate 162 is “H” and the output of the OR gate 180 is “H”, A
The output of the ND gate 163 becomes "H" and is input to the second inputs of the NAND gates 113 and 115.

The timing pulses Φ2, Φ3, Φ4 are O
The signal is input to the second input of the AND gate 110 via the R gate 108. The first input of the AND gate 110 has N
The OT gate 109 is connected. NOT gate 10
9 outputs “H”, the AND gate 110 outputs “H” only when Φ2, Φ3, and Φ4 become “H”.
Is output. The output signal of the AND gate 110 is input to the clock of the flip-flop 111 via the OR gate 107, and "H" is input to the clock only when Φ2, Φ3, and Φ4 are at “H”. These Φ2,
The pulses of Φ3 and Φ4 are the pulses shown in the timing chart of FIG.
Each time one clock is input, its output Q, Q 'is inverted. Q of the flip-flop 111 is the first input of the NAND gates 112 and 113 and the AND gate 164.
Are respectively connected to the first inputs of. Flip-flop 1
Eleven Q 'is connected to the first inputs of NAND gates 114 and 115 and the first input of 165, respectively.

The NAND gate 112 is connected to the AND gate 1
16 first inputs and stepper motor drive PMOSFE
Connected to T118. NAND gate 113
The AND gate 116 is connected to a second input of the ND gate 116 and is connected to an NMOSFET 119 for driving a step motor.
Connected to The NAND gate 114 has a first input of the AND gate 117 and a stepping motor driving PMOS.
Connected to FET 120. NAND gate 115
Is connected to a second input of an AND gate 117, and
The gate 117 is an NMOSFET for driving a step motor.
121.

The terminal 122 is a + power input terminal,
The sources of the OSFETs 118 and 120 are connected, and the NMO
The sources of the SFETs 119 and 121 are grounded to GND. The drains of the PMOSFET 118 and the NMOSFET 119 are connected to each other at a contact 185. Further, the contact 185 is connected to the coil output terminal 183 (OUT1) of the step motor 123. The coil output terminal 183 is connected to the detection NMOSF via the detection resistor 166.
Connect to the drain of ET168. Coil output terminal 18
3 and the detection resistor 166 are connected by a contact 187,
Is connected to the + input of the voltage comparator 171.

PMOSFET 120, NMOSFET 1
21 are connected to each other by a contact 186, and the other coil end output terminal 184 (O
UT2). In addition, coil end output terminal 1
84 is a detection NMOS FE via a detection resistor 167.
It is connected to the drain of T169, and is connected to the + input of the voltage comparator 170 at the contact 188. NMOSFET1
68, the NMOSFET 169 is connected to the source electrode, and the connection point is grounded.

The output of the AND gate 164 is the detection NM
The output of the AND gate 165 is connected to the OSFET 168 and the detection NMOSFET 169. Here, MOSFETs 118, 119, 120, 121,
The ON / OFF state of each of the gates 168 and 169, the voltage applied to the motor, the current flowing through the coil of the motor,
The relationship between the voltages generated in the resistors 166 and 167 will be described with reference to Table 1.

[0043]

[Table 1]

MOSFETs 118 and 121 in Table 1 are ON
In this state, when the MOSFETs 119 and 120 are turned on, a low-impedance closed loop to which a power supply voltage of 1.57 V is applied is formed. In addition, MOSFETs 119 and 12
When only 1 is turned on, a low impedance closed loop with an applied voltage of 0 V is formed. Furthermore, MOSFET1
When the MOSFET 168 or 169 is turned on while the switches 18 and 120 are turned off, the detection resistor 166 or 167 is turned on.
To form a high impedance closed loop with an applied voltage of 0V. When a low-impedance closed loop in which only the MOSFETs 119 and 121 are in the ON state is formed, the current flowing through the closed loop includes an induced current generated from the coil,
This is the sum of the current that gradually decreases due to the effect of the coil inductance component after the pulse is cut off. When a high-impedance closed loop including the detection resistor 166 or 167 is formed therein, the transient voltage ES shown in Table 1 is instantaneously generated in the detection resistor.
The transient voltage ES (hereinafter, referred to as a detection voltage ES) is a voltage generated by abruptly flowing a current flowing through a closed loop into a detection resistor having a high resistance component.

When a high impedance closed loop is formed, as shown in the timing chart of FIG.
When the OSFET 178 is also turned on, a potential difference is generated in the resistor 177, and the reference voltage VTH, which is the potential difference, is applied to the negative input terminal of the voltage converter 171. Then, the voltage converter 171 compares the potential of the detection voltage ES with the potential of the reference voltage VTH, and inputs the output signal to the OR gate 172. The relationship between the detection voltage ES and the reference voltage VTH and the output of the voltage converter 171 output “H” when “ES> VTH”, and output “ES <V”.
When "TH", "L" is output.

The output of OR gate 172 is AND gate 1
73 and a second input of the AND gate 173.
The detection pulse Ps2 shown in the timing chart of FIG. 12 is connected to the input. When the output of Ps2 is "H" and O
When the output of the R gate 172 becomes “L”, the P1 pulse width of the reverse drive pulse is too short, and the AND gate 173 outputs “L”, making the P1 pulse width longer than that of the NOT gate 175. Signal "H" is output from the terminal 181 to the reverse rotation pulse width control circuit.

On the other hand, the first input of the AND gate 174 is connected to the output of the OR gate 172, and the second input is
2 The detection pulse Ps3 shown in the timing chart is input. When the output of Ps3 is “H” and the output of OR gate 172 is “L”, the P1 pulse width of the reverse drive pulse is too long, and AND gate 174 outputs “L” and NOT gate A change signal “H” for shortening the P1 pulse width is output from 176, and a terminal 182 is output.
It is input to the reverse rotation pulse width control circuit.

Here, the output signals of the terminals 181 and 182 and the operation of the reverse rotation pulse width control circuit will be briefly described with reference to Table 2.

[0049]

[Table 2]

As shown in Table 2, when the output signals of the terminals 181 and 182 are at "L", it indicates that the pulse width is good.
When the output signal is "H", the terminal that has output the signal is the reference for changing the reverse P1 pulse width, and the terminal that outputs the signal has two terminals.
The bit signal is managed as the operation of the reverse pulse width control circuit, and the length of the pulse width is determined. The embodiment of the drive circuit and the detection circuit in FIG. 13 has been described above.

Next, regarding the reverse drive pulse width control circuit,
This will be briefly described with reference to FIG. The reverse rotation drive pulse control circuit changes the pulse width by converting the signal from the detection circuit (output signal from the terminals 181 and 182 of the detection circuit) for detecting the attenuation state of the rotor into one signal per pulse. Information processing circuit 200 (having a flip-flop, an AND gate, an OR gate, and the like) for processing presence / absence of
A pulse width adjustment circuit 201 (having an up-down counter composed of several stages of flip-flops and a binary counter) for adjusting a pulse width in accordance with a signal from the circuit 200 is provided.

The operation of the reverse drive pulse width control circuit is as follows.
A certain reference pulse is set at the same time when the power is turned on, and the pulse width is changed according to the rotation state of the clock. This change of the pulse width is performed by changing the signal “H” from the detection circuit (terminal 181 or 18).
This is performed only when 2) is input to the circuit 200, and the signal from the detection circuit is input to the circuit 200 every time a reverse pulse is output. Then, the data of the circuit 200 is reset by the reset signal Ps4 from outside each time the pulse output ends, so that the pulse width can be controlled only by the information of the detection circuit. The circuit 201 adjusts the pulse width only when the change signal φ6 of the circuit 200 is “1”.
When 6 is "0", it has a function of holding the current data. The data processed by the circuit 201 is input to the pulse waveform synthesizing circuit 13, and determines the subsequent pulse width and configuration. The above is a brief description of the reverse drive pulse width control circuit.

As the reverse drive pulse width control circuit, a conventionally devised circuit can be used, and the pulse control circuit used in the forward rotation correction drive and the present reverse drive pulse width control circuit are integrated into the same circuit. the use Te also out <br/> years, it is possible to reduce the volume occupied by the motor driver IC. Next, another embodiment of the present invention will be described below with reference to FIGS.

FIG. 14 is a drive circuit diagram of another embodiment of the present invention. MOSFET 118, 119, 12
0 and 121 use the same MOSFET as in FIG.
The motor 123 is driven. Elements for detecting the rotation state of the motor are set with resistors 300, 301, 302, and 303. NMOSFET 3 in parallel with resistors 301 and 303
06 and 308, and according to the ON / OFF state of the switch, the combined resistance (300 and 301 or 302 and 30
Switch the resistance value of 3). NMOSFET 305, 3
The switching timing of the switches 06, 307 and 308 is as follows.
According to the timing chart of FIG. Detection timings Ps2 and Ps3 for detecting the rotation state of the rotor and the reference signal P
In accordance with s1, the "H" or "L" signal is output from the AND gates 164 and 165 of FIG. NOSFE
In T305, the signal of the AND gate 164 is input, and NO
The signal of the AND gate 165 is input to the SFET 307. The output signals of the AND gates 164 and 165 alternately output “H” in each reverse rotation drive.

Therefore, "H" is set in 305 and 307 in FIG.
Are switched every time the motor is driven in reverse. This is the same for the NMOSFETs 306 and 308. By the way, when the Ps2 signal is “H”, AND
When the output signal of the gate 164 or 165 is “H”, the AND gates 309 and 310 output “H”, and N
The MOSFETs 306 and 308 are turned on. The detection resistance value at this time is the resistance value of either the resistance element 300 or 302.

When the output signals of the AND gates 309 and 310 are "L" , that is , when the Ps3 signal is "H", the detection resistance value is a value obtained by combining the resistance elements 300 and 301 or 302 and 303. . As described above, by switching the NMOSFET according to the detection timing,
The resistance value of the detection resistance element can be changed. Incidentally, the voltage for detecting the rotation state of the motor is a potential difference generated between GND and the resistance element (hereinafter, referred to as a detection voltage).
Use Then, the detected voltages are compared with the voltage comparators 311, 3
Since the method of inputting the reference voltage to the reference voltage VTH and comparing the reference voltage VTH held by the voltage comparator with the detection voltage is the same as the principle described in the previous section, detailed description is omitted in this embodiment.

In this embodiment, the detection voltage and the reference voltage VTH
Is as follows. By varying the resistance value of the detection resistance element, the detection voltage (voltage a in the figure) that is erroneously detected in the amplification of the voltage by the same resistance shown in FIG.
By switching the resistance value for each timing, FIG.
As shown in (B), all the detection voltages can be set to the same potential level. And a constant reference voltage VTH
And the detection voltage are compared, and the rotation detection is determined based on whether the voltage is higher or lower than the reference voltage VTH.

[0058]

According to the present invention, as described above, a detection circuit for detecting the rotation state of a rotor and a pulse width and a direction of application of a voltage are changed by a signal from the detection circuit during the reverse rotation of the motor. Reverse drive pulse system for
A component that allows the control circuit and all of the drive circuit that supplies the reverse rotation drive pulse to the motor to be built in the CMOS IC;
Since the rotation detection timing of the rotor is set to reverse rotation pulse output, the pulse width that enables stable and high-speed reverse rotation can be set automatically due to manufacturing variations of parts and changes in the motor environment without any cost increase. Since it can be made with a conventional motor, there is a great effect for a wristwatch pursuing low cost, high-speed reverse drive, and versatility to a variety of timepieces using one motor.

[Brief description of the drawings]

FIG. 1A shows a timing chart of a reverse rotation pulse of the present invention, and FIG. 1B shows a voltage waveform detected by a detection circuit of the present invention.

FIG. 2 is a timing chart showing a conventional reverse drive pulse.

FIGS. 3A and 3B are explanatory diagrams showing a relationship between a rotation time and a rotation speed of a rotor of a motor to which a load torque is applied.

FIGS. 4A and 4B are explanatory diagrams showing a relationship between a rotation time and a rotation speed of a rotor when a divided pulse is added to a reverse rotation pulse.

FIGS. 5A, 5B, and 5C are explanatory diagrams showing a relationship between a drive pulse, a rotation speed of a rotor, and a rotation angular speed in reverse rotation driving.

FIG. 6 is an explanatory diagram showing a rotation angle of a rotor.

FIG. 7 is an explanatory diagram showing a circuit configuration example of the present invention.

FIG. 8 is an explanatory diagram showing a drive circuit of the present invention and a path of a current flowing through the circuit.

FIG. 9 is a flowchart showing an electrical operation in the circuit of the present invention.

FIG. 10 is an explanatory diagram showing a relationship between a driving operation voltage range of a motor and an external load torque.

FIG. 11 is a circuit diagram showing an example of a drive circuit and a detection circuit according to the present invention.

FIG. 12 is a timing chart of each pulse in the reverse rotation drive of the present invention.

FIG. 13 is an explanatory diagram showing a configuration example of a reverse rotation drive pulse control circuit according to the present invention.

FIG. 14 is an explanatory diagram showing a drive circuit according to another embodiment of the present invention.

FIG. 15 is a timing chart of another embodiment of the present invention.

FIGS. 16 (A) and (B) are explanatory diagrams showing detection voltages in the present invention.

[Explanation of symbols]

 Reference Signs List 1 rotor 2 stator 12 reverse rotation signal 13 pulse waveform synthesis circuit 14 drive circuit 15 motor 16 detection circuit 17 reverse rotation pulse width control circuit

Claims (2)

(57) [Claims] 1. A timepiece stepping motor device having a reverse rotation drive device capable of rotating a rotor in a reverse direction by a reverse rotation drive pulse using at least three alternating pulses, wherein the reverse rotation drive pulse includes At least one section in which a drive pulse is interrupted and a closed loop is provided by switching of a drive circuit is provided, and switching to a circuit having a high impedance element is performed in multiple cycles, thereby causing an induced voltage generated from a rotor in the section. Is converted to a transient voltage, a position of the rotor is detected by providing a detection circuit for comparing a certain comparative voltage with the transient voltage, and further the application direction and pulse of the subsequent reverse drive pulse are detected by a signal from the detection circuit. A pulse waveform synthesizing circuit that changes the width is provided to always supply the optimal reverse drive pulse to the stepper motor. A stepping motor device for an electronic timepiece, comprising a driving circuit for supplying electric power. 2. A method according to claim 1, wherein a plurality of high impedance elements are provided on the drive circuit for converting an induced voltage that varies depending on the rotation state of the rotor into a transient voltage of the same level, and a plurality of high impedance elements are provided in accordance with a plurality of sections for detecting the transient voltage. 2. A step motor device for an electronic timepiece according to claim 1, wherein a switch is switched to a high impedance element having a different resistance value by connecting said high impedance element to detect a rotation state of said step motor.