阅读说明：本技术 电子钟表、机芯以及钟表用电机控制电路 (Electronic timepiece, movement, and timepiece motor control circuit ) 是由 奥畑友贵 于 2020-02-03 设计创作，主要内容包括：本发明提供能够使电机进行反转驱动的电子钟表、机芯及钟表用电机控制电路。电子钟表具备：电流检测部,检测流动于线圈中的电流值；驱动器控制部,根据检测出的电流值而输出第一驱动信号,在输出第一驱动信号后根据检测出的电流值而输出第二驱动信号,在输出第二驱动信号后,根据检测出的电流值而输出使转子向反转方向旋转的第三驱动信号,第一驱动信号使转子从其被吸引于第一静态稳定位置的位置起向正转方向旋转至未被吸引至第二静态稳定位置的位置为止,第二驱动信号使转子向与正转方向相反的反转方向以超过动态稳定位置的方式旋转；驱动器,根据第一至第三驱动信号而被控制为向线圈供给驱动电流的接通状态及不向线圈供给驱动电流的断开状态。(The invention provides an electronic timepiece, a movement, and a timepiece motor control circuit capable of driving a motor in a reverse direction. An electronic timepiece includes: a current detection unit that detects a value of current flowing in the coil; a driver control unit that outputs a first drive signal based on the detected current value, outputs a second drive signal based on the detected current value after outputting the first drive signal, and outputs a third drive signal for rotating the rotor in a reverse direction based on the detected current value after outputting the second drive signal, wherein the first drive signal rotates the rotor in the normal direction from a position where the rotor is attracted to the first static stable position to a position where the rotor is not attracted to the second static stable position, and the second drive signal rotates the rotor in a reverse direction opposite to the normal direction so as to exceed the dynamic stable position; and a driver which is controlled to be in an on state in which the driving current is supplied to the coil and an off state in which the driving current is not supplied to the coil according to the first to third driving signals.)

1. An electronic timepiece is characterized by comprising:

a stepping motor having a coil and a rotor, the rotor being attracted to a first statically stable position or a second statically stable position in a state where a magnetic field for driving the rotor is not generated in the coil, and being attracted to a dynamically stable position in a state where the magnetic field is generated in the coil;

a current detection unit that detects a value of current flowing through the coil;

a driver control unit that outputs a first drive signal based on the current value detected by the current detection unit and that outputs the first drive signal, a second drive signal is output according to the current value detected by the current detection unit, and a third drive signal is output according to the current value detected by the current detection unit after the second drive signal is output, wherein the first drive signal rotates the rotor in a forward direction from a position where the rotor is attracted to the first statically stable position and to a position where the rotor is not attracted to the second statically stable position, the second drive signal rotates the rotor in a reverse direction opposite to the forward direction and beyond the dynamic steady position, and the third drive signal rotates the rotor in the reverse direction;

and a driver that is controlled to be in an on state in which a drive current is supplied to the coil and an off state in which the drive current is not supplied to the coil, based on the first drive signal, the second drive signal, and the third drive signal.

2. The electronic timepiece according to claim 1,

the driver control unit controls the on state and the off state of the driver by outputting the first drive signal, and switches the drive signal to be output to the driver from the first drive signal to the second drive signal if a first on time, which is a duration of the on state corresponding to the first drive signal, or a first off time, which is a duration of the off state corresponding to the first drive signal, satisfies a predetermined condition.

3. The electronic timepiece according to claim 1,

the driver control unit switches the drive signal to be output to the driver from the first drive signal to the second drive signal if a preset time has elapsed since the start of the output of the first drive signal.

4. The electronic timepiece according to any one of claim 1 through claim 3,

the driver control unit controls the on state and the off state of the driver by outputting the second drive signal, and switches the drive signal to be output to the driver from the second drive signal to the third drive signal if a second on time, which is a duration of the on state corresponding to the second drive signal, or a second off time, which is a duration of the off state corresponding to the second drive signal, satisfies a predetermined condition.

5. The electronic timepiece according to any one of claim 1 through claim 3,

the driver control unit switches the drive signal to be output to the driver from the second drive signal to the third drive signal if a preset time has elapsed since the start of the output of the second drive signal.

6. The electronic timepiece according to claim 1,

the driver control unit outputs the third drive signal to control the on state and the off state of the driver, and stops the output of the third drive signal if a third on time, which is a duration of the on state corresponding to the third drive signal, or a third off time, which is a duration of the off state corresponding to the third drive signal, meets a predetermined condition.

7. The electronic timepiece according to claim 1,

the driver control section outputs the third drive signal of a predetermined number of steps corresponding to a target rotation amount of the rotor.

8. The electronic timepiece according to claim 7,

the driver control unit outputs a correction drive signal that generates a magnetic field in the same direction as the direction of the magnetic field generated by the last third drive signal, after the last third drive signal in the predetermined number of steps.

9. The electronic timepiece according to claim 7,

the driver control section outputs the first drive signal, then outputs the second drive signal, and then outputs the third drive signal by 1 step if a predetermined time has elapsed after the third drive signal by 1 step less than the predetermined number of steps is output.

10. A movement is characterized by comprising:

a stepping motor having a coil and a rotor, the rotor being attracted to a first statically stable position or a second statically stable position in a state where a magnetic field for driving the rotor is not generated in the coil, and being attracted to a dynamically stable position in a state where the magnetic field is generated in the coil;

a current detection unit that detects a value of current flowing through the coil;

a driver control unit that outputs a first drive signal based on the current value detected by the current detection unit and that outputs the first drive signal, a second drive signal is output according to the current value detected by the current detection unit, and a third drive signal is output according to the current value detected by the current detection unit after the second drive signal is output, wherein the first drive signal rotates the rotor in a forward direction from a position where the rotor is attracted to the first statically stable position and to a position where the rotor is not attracted to the second statically stable position, the second drive signal rotates the rotor in a reverse direction opposite to the forward direction and beyond the dynamic steady position, and the third drive signal rotates the rotor in the reverse direction;

and a driver that is controlled to be in an on state in which a drive current is supplied to the coil and an off state in which the drive current is not supplied to the coil, based on the first drive signal, the second drive signal, and the third drive signal.

11. A clock motor control circuit, comprising:

a current detection unit that detects a value of a current flowing through a coil of a stepping motor, the stepping motor having the coil and a rotor that is attracted to a first static steady position or a second static steady position in a state where a magnetic field for driving the rotor is not generated in the coil, and that is attracted to a dynamic steady position in a state where the magnetic field is generated in the coil;

a driver control unit that outputs a first drive signal based on the current value detected by the current detection unit and that outputs the first drive signal, a second drive signal is output according to the current value detected by the current detection unit, and a third drive signal is output according to the current value detected by the current detection unit after the second drive signal is output, wherein the first drive signal rotates the rotor in a forward direction from a position where the rotor is attracted to the first statically stable position and to a position where the rotor is not attracted to the second statically stable position, the second drive signal rotates the rotor in a reverse direction opposite to the forward direction and beyond the dynamic steady position, and the third drive signal rotates the rotor in the reverse direction;

and a driver that is controlled to be in an on state in which a drive current is supplied to the coil and an off state in which the drive current is not supplied to the coil, based on the first drive signal, the second drive signal, and the third drive signal.

Technical Field

The present invention relates to an electronic timepiece, a movement, and a timepiece motor control circuit.

Background

Patent document 1 discloses a technique of controlling rotation of a motor by turning off a current supplied to a coil of the motor when the current flowing through the coil exceeds an upper threshold and turning on the motor when the current is smaller than a lower threshold, and estimating a position of a rotor of the motor based on an on time during which power supply is continued or an off time during which power supply is continued to be stopped. That is, the control technique of patent document 1 discloses a method of controlling a motor by a current.

However, patent document 1 does not disclose any control technique for reversing the driving of the motor. In an electronic timepiece, in some cases, a pointer or the like is moved to a predetermined position by driving a motor in a reverse direction. Therefore, in the case of controlling the motor by current, a control technique capable of driving the motor in a reverse direction is desired.

Patent document 1: japanese Kokai publication Hei-2009-542186

Disclosure of Invention

The electronic timepiece of the present disclosure includes: a stepping motor having a coil and a rotor, the rotor being attracted to a first statically stable position or a second statically stable position in a state where a magnetic field for driving the rotor is not generated in the coil, and being attracted to a dynamically stable position in a state where the magnetic field is generated in the coil; a current detection unit that detects a value of current flowing through the coil; a driver control unit that outputs a first drive signal based on the current value detected by the current detection unit and that outputs the first drive signal, a second drive signal is output according to the current value detected by the current detection unit, and a third drive signal is output according to the current value detected by the current detection unit after the second drive signal is output, wherein the first drive signal rotates the rotor in a forward direction from a position where the rotor is attracted to the first statically stable position and to a position where the rotor is not attracted to the second statically stable position, the second drive signal rotates the rotor in a reverse direction opposite to the forward direction and beyond the dynamic steady position, and the third drive signal rotates the rotor in the reverse direction; and a driver that is controlled to be in an on state in which a drive current is supplied to the coil and an off state in which the drive current is not supplied to the coil, based on the first drive signal, the second drive signal, and the third drive signal.

In the electronic timepiece of the present disclosure, the driver control unit may output the first drive signal to control the on state and the off state of the driver, and may switch the drive signal output to the driver from the first drive signal to the second drive signal if a first on time, which is a duration of the on state corresponding to the first drive signal, or a first off time, which is a duration of the off state corresponding to the first drive signal, satisfies a predetermined condition.

In the electronic timepiece of the present disclosure, the driver control unit may switch the drive signal to be output to the driver from the first drive signal to the second drive signal if a preset time elapses from the start of the output of the first drive signal.

In the electronic timepiece of the present disclosure, the driver control unit may output the second drive signal to control the on state and the off state of the driver, and may switch the drive signal output to the driver from the second drive signal to the third drive signal if a second on time, which is a duration of the on state corresponding to the second drive signal, or a second off time, which is a duration of the off state corresponding to the second drive signal, satisfies a predetermined condition.

In the electronic timepiece of the present disclosure, the driver control unit may switch the drive signal to be output to the driver from the second drive signal to the third drive signal if a preset time elapses from the start of the output of the second drive signal.

In the electronic timepiece of the present disclosure, the driver control unit may output the third drive signal to control the on state and the off state of the driver, and the driver control unit may stop the output of the third drive signal if a third on time, which is a duration of the on state corresponding to the third drive signal, or a third off time, which is a duration of the off state corresponding to the third drive signal, meets a predetermined condition.

In the electronic timepiece of the present disclosure, the driver control unit may output the third drive signal in a predetermined number of steps corresponding to a target rotation amount of the rotor.

In the electronic timepiece of the present disclosure, the driver control unit may output a correction drive signal that generates a magnetic field in the same direction as the direction of the magnetic field generated by the last third drive signal, after the last third drive signal in the predetermined number of steps.

In the electronic timepiece of the present disclosure, the driver control unit may output the first drive signal, output the second drive signal, and output the third drive signal for 1 step if a predetermined time has elapsed after the third drive signal for 1 step less than the predetermined number of steps is output.

The movement of the present disclosure includes: a stepping motor having a coil and a rotor, the rotor being attracted to a first statically stable position or a second statically stable position in a state where a magnetic field for driving the rotor is not generated in the coil, and being attracted to a dynamically stable position in a state where the magnetic field is generated in the coil; a current detection unit that detects a value of current flowing through the coil; a driver control unit that outputs a first drive signal based on the current value detected by the current detection unit and that outputs the first drive signal, a second drive signal is output according to the current value detected by the current detection unit, and a third drive signal is output according to the current value detected by the current detection unit after the second drive signal is output, wherein the first drive signal is a signal that rotates the rotor in a forward direction from a position at which the rotor is attracted to the first statically stable position and rotates to a position at which the rotor is not attracted to the second statically stable position, the second drive signal rotates the rotor in a reverse direction opposite to the forward direction and beyond the dynamic steady position, and the third drive signal rotates the rotor in the reverse direction; and a driver that is controlled to be in an on state in which a drive current is supplied to the coil and an off state in which the drive current is not supplied to the coil, based on the first drive signal, the second drive signal, and the third drive signal.

The timepiece motor control circuit of the present disclosure includes: a current detection unit that detects a value of a current flowing through a coil of a stepping motor, the stepping motor having the coil and a rotor that is attracted to a first static steady position or a second static steady position in a state where a magnetic field for driving the rotor is not generated in the coil, and that is attracted to a dynamic steady position in a state where the magnetic field is generated in the coil; a driver control unit that outputs a first drive signal based on the current value detected by the current detection unit and that outputs the first drive signal, a second drive signal is output according to the current value detected by the current detection unit, and a third drive signal is output according to the current value detected by the current detection unit after the second drive signal is output, wherein the first drive signal is a signal that rotates the rotor in a forward direction from a position at which the rotor is attracted to the first statically stable position and rotates to a position at which the rotor is not attracted to the second statically stable position, the second drive signal rotates the rotor in a reverse direction opposite to the forward direction and beyond the dynamic steady position, and the third drive signal rotates the rotor in the reverse direction; and a driver that is controlled to be in an on state in which a drive current is supplied to the coil and an off state in which the drive current is not supplied to the coil, based on the first drive signal, the second drive signal, and the third drive signal.

Drawings

Fig. 1 is a front view of an electronic timepiece according to a first embodiment.

Fig. 2 is a circuit diagram showing a circuit configuration of the electronic timepiece of the first embodiment.

Fig. 3 is a diagram showing a configuration of a first motor of the electronic timepiece according to the first embodiment.

Fig. 4 is a configuration diagram showing a configuration of an Integrated Circuit (IC) of the electronic timepiece according to the first embodiment.

Fig. 5 is a circuit diagram showing a configuration of a first motor control circuit according to the first embodiment.

Fig. 6 is a flowchart for explaining the motor control process according to the first embodiment.

Fig. 7 is a flowchart illustrating a process of outputting the first drive signal according to the first embodiment.

Fig. 8 is a flowchart illustrating a process of outputting the second drive signal according to the first embodiment.

Fig. 9 is a flowchart illustrating a process of outputting the third drive signal according to the first embodiment.

Fig. 10 is a diagram showing signal waveforms of the first to third drive signals in the inversion control processing.

Fig. 11 is a diagram showing a state in which the rotor is rotated by the first drive signal.

Fig. 12 is a diagram showing a state in which the rotor is rotated by the second drive signal.

Fig. 13 is a diagram showing a state in which the rotor is rotated by the third drive signal.

Fig. 14 is a diagram showing signal waveforms of the first to third drive signals and the correction drive signal.

Fig. 15 is a flowchart for explaining the motor control process according to the second embodiment.

Fig. 16 is a flowchart illustrating a process of outputting the second drive signal according to the second embodiment.

Fig. 17 is a flowchart illustrating a process of outputting the third drive signal according to the second embodiment.

Fig. 18 is a diagram showing signal waveforms of the first to third drive signals.

Detailed Description

First embodiment

An electronic timepiece 1 according to a first embodiment of the present disclosure will be described below with reference to the drawings.

Fig. 1 is a front view showing an electronic timepiece 1.

The electronic timepiece 1 is a chronograph timepiece having a stopwatch function and the like.

As shown in fig. 1, the electronic timepiece 1 includes: a disc-shaped dial 2, a second hand 3, a minute hand 4, an hour hand 5, a crown 6, an A button 7, and a B button 8.

Here, in the present embodiment, the hands 3 to 5 normally display the time, but when the a button 7 is pressed for 3 seconds or more and the stopwatch mode is selected, for example, the hands 3 to 5 move to the position of 0. The position of 0 is, for example, a position of 0 minutes and 0 seconds when the hands 3 to 5 represent 0.

In this state, for example, when the a button 7 is pressed for less than 3 seconds to perform an operation for starting time measurement, the hands 3 to 5 display the elapsed time from the pressing of the a button 7.

Circuit structure of electronic timepiece

Fig. 2 is a diagram showing a circuit configuration of the electronic timepiece 1.

As shown in FIG. 2, the electronic timepiece 1 includes a movement 10 for driving hands 3 to 5.

The movement 10 is configured to include: a crystal transducer 11 as a signal source, a battery 12 as a power source, switches SW1 to SW3, a first motor 13, a second motor 14, an IC20 for a timepiece, an unillustrated train wheel, and the like.

Switch SW1 is turned on and off in conjunction with the operation of pulling out crown 6 shown in fig. 1. The switch SW2 is turned on and off in conjunction with the operation of the a button 7. The switch SW3 is turned on and off in conjunction with the operation of the B button 8.

The first motor 13 is a stepping motor for driving the second hand 3, and the second motor 14 is a stepping motor for driving the minute hand 4 and the hour hand 5. In addition, the first motor 13 and the second motor 14 are one example of the stepping motor of the present disclosure.

In addition, IC is an abbreviation of Integrated Circuit.

The IC20 includes: connection terminals OSC1 and OSC2 connected to the quartz-crystal transducer 11, input/output terminals P1 to P3 connected to switches SW1 to SW3, power supply terminals VDD and VSS connected to the battery 12, output terminals O1 and O2 connected to the first motor 13, and output terminals O3 and O4 connected to the second motor 14.

In the present embodiment, the positive electrode of the battery 12 is connected to the high-potential power supply terminal VDD, the negative electrode is connected to the low-potential power supply terminal VSS, and the low-potential power supply terminal VSS is set to the reference potential.

The crystal transducer 11 is driven by an oscillation circuit 21 described later, and generates an oscillation signal.

The battery 12 is constituted by a primary battery or a secondary battery. In the case of a secondary battery, the battery is charged by a solar cell or the like, not shown.

First motor structure

Fig. 3 is a diagram showing a structure of the first motor 13. Since the second motor 14 has the same configuration as the first motor 13, the description thereof is omitted.

As shown in fig. 3, the first motor 13 includes a stator 131, a coil 130, and a rotor 133. Both ends of the coil 130 are electrically connected to output terminals O1 and O2 of the driver 50, which will be described later. The rotor 133 is a magnet magnetized at both poles in the radial direction. Therefore, the first motor 13 is a two-pole single-phase stepping motor used in an electronic timepiece, and is driven by a motor drive current output from the output terminals O1 and O2 of the IC20 as described later.

In the present embodiment, the rotor 133 rotates in the forward direction counterclockwise and rotates in the reverse direction clockwise. That is, the counterclockwise direction is a normal rotation direction, and the clockwise direction is a reverse rotation direction.

In the present embodiment, the rotor 133 and the fourth wheel, not shown, to which the second hand 3 is attached are connected via a third wheel, not shown. When the electronic timepiece 1 is viewed from the mirror side in a plan view, that is, when viewed from the plan view as shown in fig. 1, the direction in which the second hand 3 rotates clockwise is referred to as the normal rotation direction. Note that, as for each gear for driving the second hand 3, the direction in which the second hand 3 is driven clockwise is defined as the normal rotation direction.

In the present embodiment, when the second hand 3 rotates forward in the plan view of the electronic timepiece 1 from the mirror side, the rotor 133 rotates clockwise.

However, in the present disclosure, the operation of the rotor 133 will be described in a case where the electronic timepiece 1 is viewed from the rear cover side in a plan view. That is, when the second hand 3 rotates clockwise in a plan view from the side of the front mirror, the rotor 133 rotates counterclockwise in a plan view from the side of the rear cover.

The gear that connects the rotor 133 and the second hand 3 is not limited to the above configuration, and the rotor 133 and the fourth wheel may be connected via two or more gears, for example. When the rotor 133 and the fourth wheel are connected via two gears, the rotor 133 rotates clockwise in a plan view from the back cover side when the second hand 3 rotates clockwise in a plan view from the front mirror side.

Further, a pair of inner notches 134A, 134B are provided on the inner periphery of the rotor accommodating hole of the stator 131 so as to face each other in the radial direction. The rotor 133 is intended to maintain a stationary stopped state such that a line segment passing through the N pole and the S pole is orthogonal to a line segment a-a passing through the inner notches 134A and 134B, that is, such that a line segment passing through the N pole and the S pole is along the line B-B. That is, in a state where a magnetic field for driving the rotor 133 is not generated in the coil 130, the rotor 133 is attracted to a statically stable position where a line segment passing through the N pole and the S pole of the rotor 133 is orthogonal to the a-a line. In the present embodiment, the position of the rotor 133 shown in fig. 3 is an example of the first statically stable position, and the position where the rotor 133 is rotated by 180 ° from the state shown in fig. 3 is an example of the second statically stable position.

Further, the stator 131 is provided with a pair of outer notches 135A and 135B so as to sandwich the rotor 133. When the coil 130 is energized, the rotor 133 is intended to maintain a stable stopped state such that a line segment passing through the N pole and the S pole is orthogonal to a line segment C-C passing through the outer notches 135A and 135B, that is, such that a line segment passing through the N pole and the S pole is along the D-D line. That is, when a magnetic field for driving the rotor 133 is generated in the coil 130, the rotor 133 is attracted to a dynamically stable position where a line segment passing through the N-pole and the S-pole is orthogonal to the line segment C-C.

Circuit structure of IC

Fig. 4 is a block diagram showing the structure of IC 20.

As shown in fig. 4, the IC20 includes an oscillation circuit 21, a frequency dividing circuit 22, a CPU23 for controlling the electronic timepiece 1, a ROM24, an input circuit 26, a BUS27, a first motor control circuit 30A, and a second motor control circuit 30B. The first motor control circuit 30A and the second motor control circuit 30B are examples of the timepiece motor control circuit of the present disclosure. In addition, CPU is an abbreviation for Central Processing Unit, and ROM is an abbreviation for Read Only Memory.

The oscillator circuit 21 oscillates a crystal oscillator 11 as a reference signal source shown in fig. 2 at a high frequency, and outputs an oscillation signal of a predetermined frequency (32768Hz) generated by the high frequency oscillation to the frequency divider circuit 22. The frequency dividing circuit 22 divides the output of the oscillation circuit 21 and supplies a timing signal to the CPU 23.

The ROM24 stores various programs executed by the CPU 23. In the present embodiment, the ROM24 stores programs for realizing a basic clock function and the like.

The CPU23 executes programs stored in the ROM24, thereby realizing the functions.

The input circuit 26 outputs the states of the input/output terminals P1 to P3 to the BUS 27. The BUS27 is used for data transfer and the like between the CPU23, the input circuit 26, the first motor control circuit 30A, the second motor control circuit 30B.

The first motor control circuit 30A and the second motor control circuit 30B output predetermined drive signals in accordance with commands input from the CPU23 via the BUS 27.

First motor control circuit structure

Fig. 5 is a circuit diagram showing the configuration of the first motor control circuit 30A. The second motor control circuit 30B has the same configuration as the first motor control circuit 30A, and therefore, description thereof is omitted.

The first motor control circuit 30A includes: driver control unit 40, driver 50, and current detection circuit 60.

The driver control unit 40 outputs a drive signal for rotating the rotor 133 shown in fig. 3 to the driver 50. In the present embodiment, the driver control unit 40 includes: the decoder, the timer, the differentiating circuit, the SR latch circuit, the flip-flop, the AND circuit, the OR circuit, AND the like, which are not shown in the figure, are configured as logic circuits that output gate signals P1, P2, N1, N2, N3, AND N4 to the driver 50. However, the driver control unit 40 is not limited to the above configuration, and may be configured by a control device such as a CPU, for example, and may directly control the transistors 52 to 57 of the driver 50, which will be described later, via the BUS 27.

The driver 50 includes two Pch transistors 52 and 53, four Nch transistors 54, 55, 56 and 57, and two detection resistors 58 and 59. The transistors 52 to 57 are controlled by the drive signal output from the driver control unit 40, and supply the current I in both the forward and reverse directions to the coil 130 of the first motor 13.

The current detection circuit 60 includes: a first reference voltage generating circuit 62, a second reference voltage generating circuit 63, comparators 641, 642, 651, 652, and complex gates 68, 69. The composite gate 68 is one element having a function equivalent to an element obtained by combining AND circuits 661 AND 662 AND an OR circuit 680. The composite gate 69 is one element having a function equivalent to that of an element in which the AND circuits 671 AND 672 AND the OR circuit 690 are combined.

In addition, the current detection circuit 60 is one example of the current detection section of the present disclosure.

The comparators 641 and 642 compare the voltages generated at the ends of the detection resistors 58 and 59 of the resistance values R1 and R2 with the voltage of the first reference voltage generation circuit 62, respectively.

Since the driving polarity signal PL is inverted AND input to the AND circuit 661 AND the driving polarity signal PL is input to the AND circuit 662 as it is, an output of one of the comparators 641, 642 selected by the driving polarity signal PL is output as an output DT 1.

The comparators 651, 652 compare the voltages generated at both ends of the detection resistors 58, 59 of the resistance values R1, R2 with the voltage of the second reference voltage generation circuit 63, respectively.

Since the driving polarity signal PL is inverted AND input to the AND circuit 671, AND the driving polarity signal PL is input to the AND circuit 672 as it is, an output of one of the comparators 651 AND 652 selected by the driving polarity signal PL is output as an output DT 2.

The first reference voltage generating circuit 62 is set to output a potential corresponding to a voltage generated across the detection resistors 58 and 59 when the current I flowing through the coil 130 is the lower limit current value Imin.

Therefore, when the current I flowing through the coil 130 is equal to or greater than the lower limit current value Imin, the voltage generated across the detection resistors 58 and 59 is greater than the output voltage of the first reference voltage generation circuit 62, and therefore the detection signal DT1 becomes high. On the other hand, when the current I is smaller than the lower limit current value Imin, the detection signal DT1 becomes low level. Therefore, the first reference voltage generation circuit 62, the comparators 641 and 642, and the composite gate 68 of the current detection circuit 60 are configured to be able to detect that the current I flowing through the coil 130 is smaller than the lower limit current value Imin.

The second reference voltage generation circuit 63 generates a voltage corresponding to the upper limit current value Imax. Therefore, the output DT2 of the current detection circuit 60 becomes high when the current I flowing through the coil 130 exceeds the upper limit current value Imax, and becomes low when the upper limit current value Imax is equal to or less than the upper limit current value Imax. Therefore, the second reference voltage generation circuit 63, the comparators 651 and 652, and the composite gate 69 of the current detection circuit 60 are configured to be able to detect that the current I flowing through the coil 130 exceeds the upper limit current value Imax.

Control processing of motor control circuit

Next, the control performed by the first motor control circuit 30A according to the present embodiment will be described with reference to the flowchart of fig. 6.

In addition, hereinafter, a control method for driving the second hand 3 to the position 4 of 0 second, that is, for high-speed movement, in the case where the stopwatch mode is selected by pressing the a button 7 for 3 seconds or more, for example, will be described.

Operation of motor control circuit

When the stop watch mode is set, the CPU23 of the IC20 calculates a required number of steps M1 in the case where the seconds hand 3 is moved to the 0 second position in the normal rotation direction, that is, clockwise as step S1.

Here, in the present embodiment, the second hand 3 displays seconds as 60 minutes for 1 week. That is, the number of steps M0 required to rotate the second hand 3 one turn is 60 steps. Then, the CPU23 sets the count value C of the counter to "0" when the second hand 3 is at the 0 second position, and increments the count value C by "1" every 1 step of the second hand 3. That is, the CPU23 increases the count value C to 1 to 59 so as to match the movement of the second hand 3. Therefore, the CPU23 obtains the above-described step number M1 by subtracting the count value C from 60.

Then, the CPU23 makes a determination as to whether the calculated M1 is greater than M0/2, that is, whether the number of steps M1 is greater than 60/2, that is, 30 steps. In other words, the CPU23 determines whether the second hand 3 is at the position of 0 to 29 seconds.

In this case, the CPU23 is not limited to the above, and may determine the position of the second hand 3 by determining whether or not the count value C is less than 30, for example.

When the determination in step S1 is no, that is, when the determination M1 is 30 steps or less, the second hand 3 is located at the position of 30 to 59 seconds, and therefore, it can be determined that the second hand 3 can be moved to the 0 second position with a smaller number of steps when the second hand 3 is moved clockwise. Therefore, in step S2, the CPU23 outputs a signal to the driver controller 40 to set M1 as the number of steps to rotate the rotor 133 in the normal rotation direction.

When the step number M1 is set according to the setting signal, the driver control unit 40 turns on the driver 50 of the first motor 13 by gate signals P1, P2, N1, N2, N3, and N4 as step S3. In the flowchart and the following description, the term "driver 50 is turned on" means that the driver 50 is controlled to be in an on state in which the drive current can flow in the coil 130, and the term "driver 50 is turned off" means that the driver 50 is controlled to be in an off state in which the drive current cannot flow in the coil 130.

Next, as step S4, the normal rotation drive control by the driver control unit 40 is executed. Although the normal rotation drive control is not described in detail, the driver control unit 40 moves the second hand 3 by the fast feed drive in the normal rotation drive control.

Then, in step S5, the remaining number of steps is decreased by 1 for each step, and in step S6, the driver control unit 40 determines whether or not the remaining number of steps is 0.

If no in step S6, the process returns to step S4.

If yes in step S6, it can be determined that the rotor 133 has been rotated by the number of steps M1 set in step S2, and the process is terminated.

Returning to step S1, if it is determined yes in step S1, that is, if it is determined that M1 is greater than 30 steps, the second hand 3 is at the position of 0 to 29 seconds, and therefore it can be determined that the second hand 3 can be moved to the 0 second position with a small number of steps if it is moved counterclockwise. Therefore, as step S7, the CPU23 outputs a signal to the driver control unit 40, the signal setting M2 as the number of steps of rotating the rotor 133 in the reverse direction. In this embodiment, M2 is 60 to M1. Then, as steps S100 to S300, the CPU23 outputs a signal to the driver control unit 40 to execute reverse drive control for rotating the rotor 133 in a reverse direction opposite to the normal direction.

Reverse drive control

Fig. 7 is a flowchart for explaining the first drive signal output control in the inversion drive control process of the present embodiment, fig. 8 is a flowchart for explaining the second drive signal output control, and fig. 9 is a flowchart for explaining the third drive signal output control. Fig. 10 is a diagram showing signal waveforms of the first to third drive signals in the inversion drive control process. In the present embodiment, the driver control unit 40 reverses the second hand 3 by the fast feed driving.

Fig. 11 is a diagram showing a state in which the rotor 133 rotates in response to the first drive signal, fig. 12 is a diagram showing a state in which the rotor 133 rotates in response to the second drive signal, and fig. 13 is a diagram showing a state in which the rotor 133 rotates in response to the third drive signal.

As shown in fig. 7, when the first drive signal output control S100 is executed, the driver control section 40 turns on the driver 50 of the first motor 13 by the gate signals P1, P2, N1, N2, N3, N4 as step S101. That is, the output of the first drive signal is started.

In the present embodiment, when the driver 50 is turned on, the P1 becomes low, the P2 becomes high, the Pch transistor 52 is turned on, and the Pch transistor 53 is turned off. N1 to N3 are at low level, N4 is at high level, Nch transistors 54, 55, and 56 are turned off, and Nch transistor 57 is turned on. Therefore, the drive current flows through the Pch transistor 52, the terminal O1, the coil 130, the terminal O2, the detection resistance 59, and the Nch transistor 57.

Next, as step S102, the driver control unit 40 determines whether or not a first on time Ton1, which is a duration from when the driver 50 is turned on in response to the first drive signal, exceeds a predetermined time t 11. If no in step S102, the driver control unit 40 repeatedly executes the process of step S102.

Further, in order to suppress an increase in current consumption due to a penetration current or a charge/discharge current generated at this time when the driver 50 is frequently repeatedly turned on and off, the predetermined time t11 is set to be a time at which the driver 50 is turned on at the minimum.

If yes is determined in step S102, the current detection circuit 60 determines whether or not the current I flowing through the coil 130 exceeds the upper limit current value Imax in step S103.

If the determination in step S103 is no, the current detection circuit 60 continues the determination process in step S103 until the current I exceeds the upper limit current value Imax, that is, until the voltage generated in the detection resistors 58 and 59 exceeds the reference voltage of the first reference voltage generation circuit 62.

On the other hand, if it is determined yes in step S103, in step S104, the driver control unit 40 turns off the driver 50 by the gate signals P1, P2, N1, N2, N3, and N4. Specifically, P1 is at high level, P2 is at high level, N1 is at high level, N2 is at low level, N3 is at high level, and N4 is at high level. Therefore, both ends of the coil 130 are connected to the power supply terminal VSS and short-circuited, and the supply of the current I from the driver 50 to the coil 130 is also stopped. Therefore, the state in which the current I does not flow through the coil 130 is a state in which the driver 50 is controlled to be in an off state.

Next, as step S105, the driver control section 40 determines whether or not the first on time Ton1 exceeds the predetermined time t 13.

If the determination in step S105 is no, the driver control unit 40 determines in step S106 whether or not a first off time Toff1, which is a duration from when the driver 50 is turned off in response to the first drive signal, exceeds a predetermined time t 12. If no in step S106, the driver control unit 40 repeatedly executes the process of step S106.

In addition, the predetermined time t12 is set to a time at which the driver 50 is turned off at the minimum in order to suppress frequent repetition of turning on and off of the driver 50, as in the predetermined time t 11.

If yes is determined in step S106, the current detection circuit 60 determines whether or not the current I flowing through the coil 130 is smaller than the lower limit current value Imin as step S107.

If the determination in step S107 is no, the current detection circuit 60 continues the determination process in step S107 until the current I is smaller than the lower limit current value Imin, that is, until the voltage generated in the detection resistors 58, 59 is smaller than the reference voltage of the second reference voltage generation circuit 63.

If yes in step S107, the process returns to step S101, and the process from step S101 to step S107 is repeated.

On the other hand, if it is determined yes in step S105, the driver control unit 40 performs polarity switching as step S108.

Through the processing of steps S101 to S108 described above, the first drive signal of the waveform shown in fig. 10 is output.

In this manner, in the present embodiment, the driver control unit 40 outputs the first drive signal based on the current value detected by the current detection circuit 60. That is, the driver control unit 40 turns the driver 50 on and off in accordance with the current I, and switches the polarity, that is, from the first drive signal to the second drive signal, by the first on time Ton1 based on the current I.

As shown in fig. 11, in a state where the first drive signal is output, the driver control unit 40 causes a current to flow so that a counterclockwise magnetic field is generated in the stator 131. Therefore, the rotor 133 rotates counterclockwise, that is, in the forward direction from the first statically stable position.

At this time, the predetermined time t13 is set so that the rotor 133 does not rotate to a point where a line segment passing through the N pole and the S pole of the rotor 133 exceeds the line a-a in fig. 11, that is, exceeds the intermediate point between the first statically stable position and the second statically stable position. In other words, the first drive signal is a drive signal for rotating the rotor 133 in the normal rotation direction from the position where the rotor 133 is attracted to the first statically stable position to the position where the rotor 133 is not attracted to the second statically stable position. Therefore, when the polarity is switched in step S108, an inertial force that rotates clockwise, that is, in the reverse direction acts on the rotor 133.

Here, in the present embodiment, as described above, the driver control unit 40 switches from the first drive signal to the second drive signal based on the Ton1 time based on the current I detected by the current detection circuit 60. That is, since the actuator control unit 40 estimates the position of the rotor 133 based on the first on time Ton1 and switches from the first drive signal to the second drive signal, the rotor 133 can be rotated in the normal rotation direction to a position where it is not attracted to the second statically stable position.

Next, as shown in fig. 8, when the second drive signal output control S200 is executed, the driver control section 40 turns on the driver 50 as step S201. That is, the output of the second drive signal is started.

Here, since the polarity is switched in step S108, when the driver 50 is turned on, P1 becomes high, P2 becomes low, N1, N2, and N4 become low, and N3 becomes high. Thereby, the Pch transistor 52 is turned off and the Pch transistor 53 is turned on. Further, the Nch transistors 54, 55, and 57 are turned off, and the Nch transistor 56 is turned on. Therefore, the current I flows through the Pch transistor 53, the terminal O2, the coil 130, the terminal O1, the detection resistance 58, and the Nch transistor 56. At this time, in the second drive signal, the current I flows in the opposite direction to the first drive signal.

Next, as step S202, the driver control unit 40 determines whether or not a second on time Ton2, which is a duration from when the driver 50 is turned on in response to the second drive signal, exceeds a predetermined time t 21.

The predetermined time t21 is set to a time at which the driver 50 is turned on at the minimum, similarly to the predetermined time t 11.

If it is determined as no in step S202, the driver control unit 40 repeatedly executes the process of step S202.

If yes is determined in step S202, the current detection circuit 60 executes the same processing as in step S103 as step S203.

If the determination in step S203 is no, the current detection circuit 60 continues the determination process in step S203 until the current I exceeds the upper limit current value Imax.

On the other hand, when it is determined yes in step S203, the driver control section 40 turns off the driver 50 by the gate signals P1, P2, N1, N2, N3, and N4 as step S204. Specifically, when the driver 50 is turned off, P1 becomes high, P2 becomes high, N1 becomes low, N2 becomes high, N3 becomes high, and N4 becomes high. That is, the Pch transistors 52 and 53 and the Nch transistor 54 are turned off, and the Nch transistors 55, 56, and 57 are turned on. Therefore, both ends of the coil 130 are connected to the power supply terminal VSS and short-circuited, and the supply of the current I from the driver 50 to the coil 130 is stopped.

Next, as step S205, the driver control unit 40 determines whether or not a second off time Toff2, which is a duration from when the driver 50 is turned off in response to the second drive signal, exceeds a predetermined time t 22.

The predetermined time t22 is set to a time at which the driver 50 is turned off at the minimum, similarly to the predetermined time t 12.

If no in step S205, the driver control unit 40 repeatedly executes the process of step S205.

If yes is determined in step S205, the current detection circuit 60 executes the same processing as in step S107 described above as step S206.

If the determination in step S206 is no, the current detection circuit 60 continues the determination process in step S206 until the current I is smaller than the lower limit current value Imin.

On the other hand, if it is determined yes in step S206, as step S207, the driver control portion 40 determines whether or not the second off time Toff2 exceeds the predetermined time t 23.

If no in step S207, the process returns to step S201, and the process from step S201 to step S207 is repeated.

On the other hand, if it is determined yes in step S207, the driver control unit 40 performs polarity switching as step S208.

Through the processing of steps S201 to S208 described above, the second drive signal of the waveform shown in fig. 10 is output.

In this manner, in the present embodiment, the driver control unit 40 outputs the second drive signal based on the current value detected by the current detection circuit 60. That is, the driver control unit 40 turns on and off the driver 50 in accordance with the current I, and switches the polarity, that is, from the second drive signal to the third drive signal, in accordance with the second off time Toff2 based on the current I.

As shown in fig. 12, in a state where the second drive signal is output, a clockwise magnetic field is generated in the stator 131. Therefore, the rotor 133 rotates clockwise, that is, in the reverse direction.

At this time, the predetermined time t23 is set so that the rotor 133 rotates such that a line segment passing through the N pole and the S pole of the rotor 133 exceeds the D-D line in fig. 12, that is, exceeds the dynamic steady position. In other words, the second drive signal is a drive signal for rotating the rotor 133 in the reverse direction and exceeding the dynamic steady position.

Here, when the second drive signal is output in a state where the rotor 133 is at the first statically stable position, that is, in a state where a line segment passing through the N pole and the S pole of the rotor 133 extends along the line B-B shown in fig. 11, the distance from the first statically stable position to the dynamically stable position shown in fig. 12 is short. Therefore, the inertial force of the rotor 133 when rotating from the first statically stable position to the dynamically stable position is small, and it is difficult for the rotor to rotate beyond the dynamically stable position.

In contrast, in the present embodiment, as described above, the rotor 133 is rotated in the normal rotation direction to a position not exceeding the neutral point in accordance with the first drive signal, and thereafter, outputs the second drive signal in a state where the inertial force rotating in the reverse rotation direction acts, and is attracted in the reverse rotation direction. Therefore, the inertial force of the rotor 133 rotating in the reverse direction acts largely, and thus the rotor can rotate beyond the dynamic stable position.

In the present embodiment, as described above, the driver control unit 40 switches from the second drive signal to the third drive signal in accordance with the second off time Toff2 based on the current I. That is, the driver control unit 40 estimates the position of the rotor 133 based on the second off time Toff2 and switches from the second drive signal to the third drive signal, so that the rotor 133 can be rotated to exceed the dynamic steady position.

Next, as shown in fig. 9, when the third drive signal output control S300 is executed, the driver control section 40 turns on the driver 50 as step S301. That is, the output of the third drive signal is started.

Here, since the polarity is switched in step S208, the driver 50 is in the same state as in step S101 described above.

Next, as step S302, the driver control unit 40 determines whether or not a third on time Ton3, which is a duration from when the driver 50 is turned on in response to the third drive signal, exceeds a predetermined time t 31.

The predetermined time t31 is set to a time at which the driver 50 is turned on at the minimum, similarly to the predetermined time t 11.

If it is determined as no in step S302, the driver control unit 40 repeatedly executes the process of step S302.

If yes is determined in step S302, the current detection circuit 60 executes the same processing as in steps S103 and S203 described above as step S303.

If the determination in step S303 is no, the current detection circuit 60 continues the determination process in step S103 until the current I exceeds the upper limit current value Imax.

On the other hand, if it is determined yes in step S303, the driver control unit 40 turns off the driver 50 as step S304, in the same manner as in step S104 described above.

Next, as step S305, the driver control unit 40 determines whether or not a third off time Toff3, which is a duration from when the driver 50 is turned off in response to the third drive signal, exceeds a predetermined time t 32.

The predetermined time t32 is set to a time at which the driver 50 is turned off at the minimum, similarly to the predetermined time t 12.

If no in step S305, the driver control unit 40 repeatedly executes the process of step S305.

If yes is determined in step S305, the current detection circuit 60 executes the same processing as in steps S107 and S206 as step S306.

If the determination in step S306 is no, the current detection circuit 60 continues the determination process in step S306 until the current I is smaller than the lower limit current value Imin.

On the other hand, if it is determined yes in step S306, as step S307, the driver control portion 40 determines whether the third off time Toff3 exceeds the predetermined time t 33. If no in step S307, the process returns to step S301, and the process from step S301 to step S307 is repeated.

On the other hand, if it is determined yes in step S307, the driver control unit 40 performs polarity switching as step S308.

In this manner, in the present embodiment, the driver control unit 40 outputs the third drive signal based on the current value detected by the current detection circuit 60. That is, the driver control unit 40 turns on and off the driver 50 in accordance with the current I, and switches the polarity, that is, stops the output of the third drive signal in accordance with the third off time Toff3 based on the current I.

Here, as shown in fig. 13, in a state where the third drive signal is output, a counterclockwise magnetic field is generated in the stator 131. Thereby, the rotor 133 rotates clockwise, that is, in the reverse direction.

Here, in the present embodiment, as described above, the driver control unit 40 stops the output of the third drive signal in accordance with the third off time Toff3 based on the current I. That is, the driver control unit 40 estimates the position of the rotor 133 based on the third off time Toff3 and switches the polarity of the third drive signal, so that the rotor 133 can be reliably rotated in the reverse direction.

When the polarity is switched from the state shown in fig. 13 and the third drive signal is output, a clockwise magnetic field is generated in the stator 131.

Returning to fig. 6, after the third drive signal output control S300 ends, the driver control section 40 decrements the remaining number of steps by 1 as step S8.

Then, as step S9, the driver control unit 40 determines whether or not the remaining number of steps is 0.

If no in step S9, the process of step S300 is repeated. That is, the driver control section 40 outputs the third drive signal of the predetermined number of steps M2 corresponding to the target rotation amount of the rotor 133.

If yes in step S9, the driver control unit 40 determines as step S10 whether or not the elapsed time T4 from the stop of the output of the last third drive signal in the predetermined number of steps M2 exceeds the predetermined time T4.

The predetermined time t4 is set to a time to the extent that the rotor 133 is stopped properly, for example, a time of about 10 msec.

If no in step S10, the driver control section 40 repeats the processing until yes in step S10.

If yes in step S10, the driver control unit 40 switches the polarity as step S11.

Then, in step S12, the driver control unit 40 outputs the correction drive signal.

Fig. 14 is a diagram showing signal waveforms of the first to third drive signals and the correction drive signal.

As shown in fig. 14, the driver control unit 40 outputs the correction drive signal having the same polarity as the last third drive signal in the predetermined number of steps M2. That is, the correction drive signal generates a magnetic field having the same direction as the direction of the magnetic field generated by the last third drive signal.

Then, if the correction drive signal is output in step S12, the drive control of the second hand 3 is ended.

Operational effects of the first embodiment

According to the first embodiment, the following effects can be obtained.

In the present embodiment, the electronic timepiece 1 includes the driver control unit 40, and the driver control unit 40 outputs the first to third drive signals to the driver 50 based on the current value detected by the current detection circuit 60. That is, the driver control unit 40 turns on and off the driver 50 in accordance with the current I detected by the current detection circuit 60, and switches the polarity based on the on state or the off state duration of the driver 50. Then, the driver control unit 40 outputs a first drive signal that rotates the rotor 133 in the normal rotation direction from the position where the rotor 133 is attracted to the first statically stable position to the position where the rotor 133 is not attracted to the second statically stable position. Then, the driver control unit 40 outputs a second drive signal that rotates the rotor 133 in a reverse direction opposite to the normal direction and beyond the dynamic steady position. Then, the driver control unit 40 outputs a third drive signal for rotating the rotor 133 in the reverse direction.

Accordingly, the rotor 133 is rotated in the normal direction by the first drive signal and is rotated so as not to exceed the intermediate point between the first statically stable position and the second statically stable position, and the second drive signal for rotating the rotor 133 in the reverse direction is output in a state where the inertial force in the reverse direction acts on the rotor 133. Therefore, the rotor 133 can be rotated beyond the dynamic stable position by the second drive signal. Then, in a state where the dynamic stable position is exceeded, the third drive signal for rotating the rotor 133 in the reverse direction is output, so that the rotor 133 can be reversed. Therefore, when the first motor 13 is controlled by the current, the first motor 13 can be driven in reverse.

Further, since the driver control unit 40 estimates the position of the rotor 133 based on the current I and switches from the first drive signal to the second drive signal, the rotor 133 can be rotated in the normal rotation direction to a position not attracted to the second statically stable position with certainty.

Further, the driver control unit 40 estimates the position of the rotor 133 based on the current I and switches from the second drive signal to the third drive signal, so that the rotor 133 can be rotated to exceed the dynamic steady position.

Further, the driver control unit 40 estimates the position of the rotor 133 based on the current I and switches the polarity of the third drive signal, so that the rotor 133 can be appropriately rotated in the reverse direction.

In the present embodiment, if the duration of the off state corresponding to the second drive signal, i.e., the second off time Toff2, exceeds the predetermined time t23, the driver control unit 40 switches the drive signal output to the driver 50 from the second drive signal to the third drive signal.

Further, if the duration of the off state corresponding to the third drive signal, i.e., the third off time Toff3, exceeds the predetermined time T33, the driver control part 40 stops the output of the third drive signal.

That is, the position of the rotor 133 is inferred based on the second off-time Toff2 and the third off-time Toff3, and switching of the driving signal is performed. Therefore, as compared with a case where the drive signal is output for a predetermined time, that is, as compared with a case where the fixed pulse is output, even if a load is applied to the rotor 133 or a disturbance occurs, the rotor 133 can be inverted stably.

In the present embodiment, the driver control unit 40 outputs the third drive signal of the predetermined number of steps M2 corresponding to the target rotation amount of the rotor 133. This allows the rotor 133 to be rotated reversely by a desired rotation amount. Therefore, for example, the second hand 3 can be moved to a desired position by controlling the first motor 13 to be driven in reverse.

Further, since the driver control unit 40 outputs only the third drive signal of the predetermined number of steps M2 without outputting the first and second drive signals after the second step, the current consumption can be reduced as compared with the case where the first to third drive signals are output for each step.

In the present embodiment, the driver control unit 40 outputs the correction drive signal that generates the magnetic field in the same direction as the direction of the magnetic field generated by the last third drive signal in the predetermined number of steps M2, after the last third drive signal.

Accordingly, when the rotor 133 normally operates, the rotor 133 is stopped in a state where the direction of the magnetic field generated by the last third drive signal is attracted, and therefore, even if the magnetic field having the same direction as the correction drive signal is generated, the rotor is not rotated but is maintained in the stopped state.

On the other hand, when the rotor 133 exceeds the limit, that is, when the rotor is inverted by 1 step more, the rotor 133 is stopped in a state where it repels the direction of the magnetic field generated by the last third drive signal. Therefore, by generating a magnetic field in the same direction as the last third drive signal by the correction drive signal, the rotor 133 can be rotated forward by 1 step and returned to the same state as that at the end of the normal operation.

At this time, in the present embodiment, the correction drive signal is output after the predetermined time t4 has elapsed after the output of the last third drive signal in the predetermined number of steps M2 is stopped, that is, after the rotor 133 is surely stopped. Therefore, the rotation of the rotor 133 can be prevented from increasing more than the predetermined number of steps M2 due to the correction of the drive signal.

Second embodiment

Next, a second embodiment of the present disclosure will be described with reference to fig. 15 to 18. The second embodiment is different from the first embodiment in that the second drive signal is switched to the third drive signal based on the second on time Ton2, and the output of the third drive signal is stopped based on the third on time Ton 3. The second embodiment is different from the first embodiment described above in that the first to third drive signals are output by one step after the remaining number of steps becomes 1 and after a predetermined time t4 has elapsed.

In the second embodiment, the same or similar components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

Control processing of motor control circuit

Fig. 15 is a flowchart showing a motor control process according to the second embodiment. In fig. 15, steps S1 to S8 and S10 are the same as those in the first embodiment described above, and therefore, the description thereof is omitted.

As shown in fig. 15, if it is determined yes in step S1, the CPU23 outputs a signal for setting M2, which is the number of steps for rotating the rotor 133 in the reverse direction, to the driver controller 40 as step S7. Then, as steps S100, S400, and S500, the CPU23 outputs signals for executing the first to third drive signal output control to the driver control unit 40.

Reverse drive control

Fig. 16 is a flowchart for explaining the second drive signal output control S400 in the inversion drive control process according to the present embodiment, and fig. 17 is a flowchart for explaining the third drive signal output control S500. In the present embodiment, the first drive signal output control S100 is the same as that of the first embodiment described above, and therefore, the description thereof is omitted. In fig. 16, steps S401 to S404 and S406 to S408 are the same as steps S101 to S104 and S106 to S108 of the first embodiment described above, and therefore, the description thereof is omitted. In fig. 17, steps S501 to S504 and S506 to S508 are the same as steps S101 to S104 and S106 to S108 of the first embodiment described above, and therefore, the description thereof is omitted.

As shown in fig. 16, in the present embodiment, after the driver 50 is turned off in step S404, the driver control unit 40 determines whether or not the second on time Ton2 exceeds the predetermined time t24 as step S405. That is, the driver control section 40 is configured to switch from the second drive signal to the third drive signal without waiting until the current I becomes smaller than the lower limit current value Imin if the duration of the on state of the driver 50, that is, the second on time Ton2 exceeds the predetermined time t24 as the predetermined condition.

Further, as shown in fig. 17, after the driver 50 is turned off in step S504, the driver control portion 40 determines whether or not the third on time Ton3 exceeds the predetermined time t34 as step S505. That is, the driver control section 40 is configured to stop the output of the third drive signal without waiting until the current I is smaller than the lower limit current value Imin if the duration of the on state of the driver 50, that is, the third on time Ton3 exceeds the predetermined time t34 as the predetermined condition.

Returning to fig. 15, in step S13, the driver control unit 40 determines whether or not the remaining number of steps is 1.

If no in step S13, the process returns to step S500, and the third drive signal output control is repeated. That is, the driver control section 40 outputs the third drive signal of the number of steps 1 time less than the predetermined number of steps M2 corresponding to the target rotation amount of the rotor 133.

If the determination in step S13 is yes, the driver control unit 40 determines whether or not the elapsed time T4 from the stop of the output of the last third drive signal exceeds the predetermined time T4 as in step S10, as in the first embodiment described above.

If no in step S10, the driver control unit 40 repeats the processing until yes in step S10.

If yes is determined in step S10, the driver control unit 40 executes first drive signal output control in step S100. Then, as step S400, the driver control section 40 executes second drive signal output control. Then, as step S500, the driver control section 40 executes third drive signal output control.

Fig. 18 is a diagram showing signal waveforms of the first to third drive signals in the present embodiment.

As shown in fig. 18, if a predetermined time t4 elapses after the output of the third driving signal of the M2-1 th step is stopped, the driver control part 40 outputs the first to third driving signals of 1 step amount.

Then, if the third drive signal is output in step S500, the drive control of the second hand 3 is ended.

Operational effects of the second embodiment

According to the second embodiment, the following effects can be obtained.

In the present embodiment, if the duration of the on state corresponding to the first drive signal, i.e., the first on time Ton1, exceeds the predetermined time t13, the driver control unit 40 switches the drive signal output to the driver 50 from the first drive signal to the second drive signal.

Further, if the duration of the on state corresponding to the second drive signal, that is, the second on time Ton2 exceeds the predetermined time t24, the driver control portion 40 switches the drive signal output to the driver 50 from the second drive signal to the third drive signal.

In addition, if the duration of the on state corresponding to the third drive signal, i.e., the third on time Ton3, exceeds the predetermined time t34, the driver control portion 40 stops the output of the third drive signal.

That is, in the present embodiment, the driver control unit 40 estimates the position of the rotor 133 based on the first on time Ton1, the second on time Ton2, and the third on time Ton3, and switches the drive signal. Thus, the driver control unit 40 switches the polarity without waiting until the current I becomes smaller than the lower limit current value Imin after turning off the driver 50, and therefore, the time for which each drive signal is output can be shortened as compared with a case where the switching of the drive signal is performed based on the off time, which is the duration of the off state of each drive signal. Therefore, current consumption can be suppressed.

In the present embodiment, after outputting the third drive signal that is 1 step smaller than the predetermined number of steps M2, the driver control section 40 outputs the first drive signal, then outputs the second drive signal, and then outputs the third drive signal for 1 step if the predetermined time t4 has elapsed.

Therefore, the rotor 133 can be prevented from rotating in an excessive manner, that is, from rotating in 1 more step.

Modification example

The present disclosure is not limited to the above-described embodiments, and modifications, improvements, and the like within a range that can achieve the object of the present disclosure are included in the present disclosure.

In each of the above embodiments, the driver control unit 40 switches the drive signal to be output to the driver 50 from the first drive signal to the second drive signal based on the first on time Ton1, but the present invention is not limited to this. For example, the driver control unit 40 may be configured to switch the drive signal to be output to the driver 50 from the first drive signal to the second drive signal based on the first off time Toff 1. Further, the driver control unit 40 may be configured to switch the drive signal to be output to the driver 50 from the first drive signal to the second drive signal if a predetermined time has elapsed since the start of the output of the first drive signal.

In the first embodiment, the driver control unit 40 switches the drive signal to be output to the driver 50 from the second drive signal to the third drive signal based on the second off time Toff2, but the present invention is not limited to this. For example, the driver control unit 40 may be configured to switch the drive signal output to the driver 50 from the second drive signal to the third drive signal based on the second on time Ton 2. Further, the driver control unit 40 may be configured to switch the drive signal to be output to the driver 50 from the second drive signal to the third drive signal if a predetermined time elapses from the start of the output of the second drive signal.

In the second embodiment, the driver control unit 40 switches the drive signal to be output to the driver 50 from the second drive signal to the third drive signal based on the second on time Ton2, but the present invention is not limited to this. For example, the driver control unit 40 may be configured to switch the drive signal output to the driver 50 from the second drive signal to the third drive signal based on the second off time Toff 2. Further, the driver control unit 40 may be configured to switch the drive signal to be output to the driver 50 from the second drive signal to the third drive signal if a predetermined time elapses from the start of the output of the second drive signal.

In the first embodiment, the driver control unit 40 stops the third drive signal output to the driver 50 based on the third off time Toff3, but the present invention is not limited to this. For example, the driver control unit 40 may be configured to stop the third drive signal output to the driver 50 based on the third on time Ton 3.

In the second embodiment, the driver control unit 40 stops the third drive signal output to the driver 50 based on the third on time Ton3, but the present invention is not limited to this. For example, the driver control unit 40 may be configured to stop the third drive signal output to the driver 50 based on the third off time Toff 3.

In the first embodiment, the driver control unit 40 outputs the correction drive signal after outputting the last third drive signal, but the present invention is not limited to this. For example, the present disclosure also includes a case where the driver control unit 40 does not output the correction drive signal.

Further, as in the second embodiment, the driver control unit 40 may be configured to output the third drive signal having the number of steps 1 time smaller than the predetermined number of steps M2 corresponding to the target rotation amount of the rotor 133, and then output the first to third drive signals.

In the second embodiment, the driver control unit 40 may be configured to output the third drive signal in the number of steps 1 time less than the predetermined number of steps M2 according to the target rotation amount of the rotor 133, and output the first to third drive signals and then output the correction drive signal.

The driver control unit 40 may be configured to output the third drive signal of the predetermined number of steps M2 according to the target rotation amount of the rotor 133, or may be configured to output the correction drive signal after the last third drive signal is output.

In the above embodiments, the predetermined times t11, t21, and t31 are set as the times for which the driver 50 is turned on at the minimum, but the present disclosure includes cases where these predetermined times are not set.

Similarly, in each of the above embodiments, the predetermined times t12, t22, and t32 are set as the time for which the driver 50 is turned off at the minimum, but the present disclosure also includes a case where these predetermined times are not set.

In the above embodiments, the electronic timepiece 1 is a wristwatch-type timepiece, but may be a counter-type timepiece. The timepiece motor control circuit according to the present disclosure is not limited to controlling a motor that drives a hand of a timepiece, and can be applied to a motor control circuit for a calendar wheel, for example.

Description of the symbols

1 … electronic timepiece; 10 … movement; 11 … quartz crystal transducer; 12 … batteries; 13 … first motor (stepper motor); 21 … oscillating circuit; 22 … frequency divider circuit; 23 … CPU; 24 … ROM; 26 … input circuit; 27 … BUS; 30a … first motor control circuit (timepiece motor control circuit); 40 … a driver control section; a 50 … driver; 60 … current detection circuit (current detection unit); 130 … coil; 131 … stator; 133 … rotor.