阅读说明：本技术 指针驱动装置、电子表、指针驱动方法以及记录介质 (Hand driving device, electronic timepiece, hand driving method, and recording medium ) 是由 大村龙义 泽田亮 于 2020-11-24 设计创作，主要内容包括：本发明提供指针驱动装置、电子表、指针驱动方法以及记录介质。指针驱动装置具备第一～第三步进电动机、驱动电路、磁传感器以及处理器。第一～第三步进电动机使指针动作。驱动电路驱动第一～第三步进电动机。处理器基于第一～第三步进电动机的动作来控制磁传感器,在磁传感器未进行测定的状态下,判定驱动电路是否使步进电动机旋转,若判定为步进电动机未旋转,则使磁传感器开始测定。(The invention provides a hand driving device, an electronic timepiece, a hand driving method, and a recording medium. The pointer driving device includes first to third stepping motors, a driving circuit, a magnetic sensor, and a processor. The first to third stepping motors operate the hands. The drive circuit drives the first to third stepping motors. The processor controls the magnetic sensor based on the operations of the first to third stepping motors, determines whether or not the drive circuit rotates the stepping motor in a state where the magnetic sensor is not measuring, and starts the measurement with the magnetic sensor when the drive circuit determines that the stepping motor is not rotating.)

1. A hand driving device is characterized in that,

the pointer driving device includes:

a motor that operates a pointer:

a drive circuit that drives the motor:

magnetic sensor: and

a processor that controls the magnetic sensor based on an action of the motor,

the processor determines whether or not the drive circuit rotates the motor in a state where the magnetic sensor is not measuring, and starts the measurement with the magnetic sensor if it is determined that the motor is not rotating.

2. The pointer driving apparatus as claimed in claim 1,

the processor does not start measurement by the magnetic sensor if it is determined that the motor is rotating.

3. The pointer driving apparatus as claimed in claim 1,

the processor controls the drive circuit to stop the rotation of the motor when it is determined that the intensity of the magnetic field obtained by the measurement of the magnetic sensor is equal to or greater than a first reference value.

4. The pointer driving apparatus as claimed in claim 1,

the drive circuit drives the motor by outputting a first current or a first voltage to the motor,

the processor controls the drive circuit to output a second current or a second voltage, which is larger than the first current or the first voltage, to the motor when it is determined that the intensity of the magnetic field obtained by the measurement of the magnetic sensor is equal to or less than a first reference value.

5. The pointer driving apparatus as claimed in claim 1,

the processor stops the measurement of the magnetic sensor when it is determined that the intensity of the magnetic field obtained by the measurement of the magnetic sensor is less than a second reference value that is smaller than a first reference value.

6. The pointer driving apparatus as claimed in claim 5,

the processor counts a period during which rotation of the motor is stopped, and causes the drive circuit to rotate the motor based on the period during which rotation of the motor is stopped after the magnetic sensor is stopped for measurement.

7. The pointer driving apparatus as claimed in claim 6,

the processor causes the drive circuit to rotate the motor to move the position of the pointer to a certain position when a period during which rotation of the motor is stopped is equal to or longer than a reference period, and the position of the pointer indicates a current time.

8. The pointer driving apparatus as claimed in claim 1,

the motor is a stepping motor having: a rotor having a magnet; and a stator having a coil for rotating the rotor,

the processor detects whether the rotor of the stepping motor rotates according to the pulse output from the drive circuit, thereby determining whether the motor rotates.

9. The pointer driving apparatus as claimed in claim 8,

the processor outputs a current difference detection pulse to the drive circuit, and determines whether the rotor is rotating based on a current flowing through the coil.

10. The pointer driving apparatus as claimed in claim 8,

the processor changes at least 1 of an applied voltage and a pulse width of a correction pulse output from the drive circuit to the motor, based on the magnetic field intensity obtained by the measurement of the magnetic sensor.

11. The pointer driving apparatus as claimed in claim 1,

the pointer driving device further includes a potentiometer that converts a rotation angle of the motor into an electric signal and outputs the electric signal, or an optical rotation detecting device that irradiates a rotating body including a rotation shaft of the motor with light and detects reflected light reflected by the rotating body to detect rotation,

the processor determines whether or not the drive circuit rotates the motor based on a detection result detected by the potentiometer or the optical rotation detecting device.

12. The pointer driving apparatus as claimed in claim 1,

the processor reports information on the magnetic field to a user when the magnetic field obtained by the measurement by the magnetic sensor is determined to be equal to or greater than a third reference value.

13. An electronic timepiece is characterized in that it comprises a case,

the electronic timepiece includes:

the pointer driving apparatus of claim 1; and

a pointer driven by the pointer driving means.

14. A pointer driving method for driving a pointer in a pointer driving device including a motor for operating the pointer, a driving circuit for driving the motor, and a magnetic sensor,

the pointer driving method includes: and a control step of determining whether or not the motor is rotated by the drive circuit in a state where the magnetic sensor is not measuring, and starting the measurement by the magnetic sensor when it is determined that the motor is not rotating.

15. A recording medium storing a program, characterized in that,

the program causes the processor for controlling a pointer driving device including a motor, a driving circuit, and a magnetic sensor to function as:

determining whether or not the motor is rotated by the drive circuit in a state where the magnetic sensor is not measuring, and starting the measurement by the magnetic sensor if it is determined that the motor is not rotating,

wherein the motor operates a pointer, and the drive circuit drives the motor.

Technical Field

The present invention relates to a hand driving device, an electronic timepiece, a hand driving method, and a recording medium.

Background

For example, japanese patent application publication No. 2019-49436 discloses an electronic timepiece including: a stepping motor having a rotor, a stator, and a coil in which a wire is wound around a coil winding core: and a magnetic shield plate covering at least a part of the stepping motor.

Disclosure of Invention

The present embodiment is characterized by comprising: a motor for operating the pointer; a drive circuit that drives the motor; a magnetic sensor; and a processor that controls the magnetic sensor based on an action of the motor,

the processor determines whether or not the drive circuit rotates the motor in a state where the magnetic sensor is not measuring, and starts the measurement with the magnetic sensor if it is determined that the motor is not rotating.

Drawings

Fig. 1 shows an electronic timepiece of an embodiment.

Fig. 2 shows a stepping motor according to an embodiment.

Fig. 3 is a block diagram showing a configuration of a pointer driving device according to an embodiment.

Fig. 4 is a flowchart showing a needle travel control process according to the embodiment.

Fig. 5 is a flowchart showing a first stitch processing according to the embodiment.

Fig. 6 is a flowchart showing a second stitch processing according to the embodiment.

Fig. 7 illustrates a needle travel control process according to the embodiment.

Fig. 8 shows an electronic timepiece according to a modification.

Fig. 9 shows an electronic timepiece according to a modification.

Detailed Description

Hereinafter, the hand driving device and the electronic timepiece according to the present embodiment will be described with reference to the drawings.

As shown in fig. 1, the electronic timepiece 1 of the present embodiment is a wristwatch including hands 20a to 20c, a dial 30, a case 40, a band 50, and a hand driving device 100. The hand driving device 100 drives hands 20a to 20c, and includes first to third stepping motors (motors) 120a to 120c, a driving circuit 130, a timer circuit 140, a magnetic sensor 150, a power supply unit 160, and a control unit 110. The motor drive device 200 includes the first to third stepping motors 120a to 120c, the drive circuit 130, the control unit 110, and the timer circuit 140.

Hand 20a is a second hand indicating seconds, hand 20b is a minute hand indicating minutes, and hand 20c is an hour hand indicating time. The hands 20a to 20c are rotatably provided with respect to the rotation axis of the dial 30. The dial 30 is a display panel having hour characters 31 representing time. The case 40 has a glass cover 41 covering the hands 20a to 20c and the dial 30 and a crown 42 adjusting the positions of the hands 20a to 20c, and houses the hands 20a to 20c, the dial 30, and the hand driving device 100. Band 50 is mounted to case 40 for wearing on the wrist.

The first stepping motor 120a drives the hand 20a as the second hand via 1 or more gears. The second stepping motor 120b drives the hand 20b as a minute hand via 1 or more gears. The third stepping motor 120c drives the hand 20c as an hour hand via 1 or more gears.

As shown in fig. 2, the first to third stepping motors 120a to 120c have the same structure, and include a rotor 61, a stator 62, and a coil 63. The rotor 61 is disposed to be rotatable about an unillustrated shaft provided on the stator 62. The rotor 61 can be rotated at a predetermined step angle in any one of the clockwise direction and the counterclockwise direction by applying a driving pulse to the coil 63. For example, 1 or more gears for moving the hand 20a as the second hand are coupled to the rotor 61, and the rotation of the rotor 61 rotates the gears.

Stator 62 has a core formed in a substantially rectangular frame shape around which coil 63 is wound, and has circular hole 64 formed therein, and rotor 61 is disposed in hole 64. When a current flows in the coil 63, magnetic poles appear in the stator 62 near the regions 65, 66. The polarities of the magnetic poles of the regions 65 and 66 are determined according to the direction of the current flowing through the coil 63. The coil 63 is connected to the drive circuit 130 via a terminal block 67.

When a voltage is applied to the coil 63 so that magnetic poles repelling the S pole 61S and the N pole 61N appear in the regions 65, 66, the rotor 61 rotates. In addition, 2 recesses 64a are formed in the stator 62 on the inner circumferential surface of the hole 64 for accommodating the rotor 61. The stationary state of the rotor 61 can be maintained by these 2 recesses 64 a.

In a state where the S pole 61S and the N pole 61N face the regions 65 and 66, the indexing torques (holding torques) of the first to third stepping motors 120a to 120c become maximum. Therefore, in the non-energized state in which no drive pulse is applied, the rotor 61 is magnetically stabilized and stopped at the stop position shown in fig. 2 or at the stop position rotated 180 degrees from the stop position.

The drive circuit 130 has a bridge circuit for driving the first to third stepping motors 120a to 120c, and applies a voltage to the coils 63 of the first to third stepping motors 120a to 120c in accordance with an instruction from the control unit 110. More specifically, the drive circuit 130 applies a drive pulse, a correction pulse, and a current difference detection pulse to the coil 63, and includes a switching element formed of a MOSFET (Metal-Oxide-semiconductor field-effect transistor) and an H-bridge circuit formed of a resistance element. The switching element and the resistance element constitute a discharge circuit that discharges the energy stored in the coil 63. The terminal voltage of the coil 63 is referred to as a coil voltage V1, and the current flowing through the coil 63 is referred to as a coil current I1.

The timer circuit 140 is a counter circuit that counts the current time and includes an oscillator circuit and a frequency divider circuit. The oscillation circuit uses a circuit that oscillates in combination with a vibrator such as quartz crystal, and generates a unique frequency signal and outputs the signal to the frequency dividing circuit. The frequency dividing circuit divides a signal input from the oscillation circuit into signals of frequencies and outputs the signals. The timing circuit 140 counts the number of times of the predetermined frequency signal output from the frequency dividing circuit and adds the counted number to the initial time, thereby counting the current time.

The magnetic sensor 150 measures data for deriving the magnetic field strength, and derives and acquires data indicating the magnetic field strength. And outputs the acquired data to the control unit 110. The control unit 110 may derive and acquire data indicating the magnetic field strength based on data including a current value, a resistance value, an impedance, and the like for deriving the magnetic field strength measured by the magnetic sensor 150. In the initial state, the magnetic sensor 150 is set to OFF (OFF) and no power is supplied to measure the magnetic field strength. Here, the off includes a mode in which the magnetic field strength is not measured, such as when a power saving mode such as a sleep mode is set. The magnetic sensor 150 can use a hall element that detects the intensity of a magnetic field using the hall effect, a magnetoresistive element that measures the magnitude of a magnetic field using the magnetoresistive effect in which the resistance of a solid changes due to a magnetic field, or the like. Further, the intensity of the magnetic field may be detected by outputting a pulse to a wire such as an amorphous wire and detecting a change in the magnetic field by a coil.

The power supply unit 160 includes a battery and a DC-DC converter, and has a configuration capable of keeping an output voltage during operation constant and stably operating the hand driving device 100 for a long time.

The control Unit 110 includes a CPU (Central Processing Unit), a ROM (read only memory), a RAM (random access memory), and the like. The control unit 110 reads out a program stored in the ROM to the RAM and executes the program, thereby functioning as a pointer control unit 111, a rotation determination unit 112, a magnetic sensor control unit 113, a magnetism determination unit 114, and a time counting unit 115.

The hand control unit 111 controls the drive circuit 130 to drive the first to third stepping motors 120a to 120c based on the current time counted by the timer circuit 140. The drive circuit 130 controlled by the hand control unit 111 outputs drive pulses to the first to third stepping motors 120a to 120c once a second, and rotates the rotor 61. When the rotor 61 rotates, the hands 20a to 20c rotate via 1 or more gears. However, for example, when a magnetic field is applied to the electronic timepiece 1, the rotor 61 may not be rotated by the drive pulse. In this case, the pointer control unit 111 can output a correction pulse larger than the drive pulse in at least one of the applied voltage and the pulse width. For example, when the rotation of the rotor 61 fails, if the magnetism determination unit 114 determines that the magnetic field strength acquired by the magnetic sensor control unit 113 is smaller than the first reference value, a correction pulse stronger than the drive pulse is output. The control of the first reference value and the case where it is determined that the first reference value is equal to or greater than the first reference value will be described later. When the magnetism determination unit 114 determines that the magnetic field intensity obtained by the magnetic sensor control unit 113 is smaller than the second reference value, the hand control unit 111 controls the drive circuit 130 to drive the first to third stepping motors 120a to 120c based on the period of time during which the rotation of the rotor 61 is stopped, which is counted by the time counting unit 115. Thereby, the positions of the hands 20a to 20c are returned to the positions indicating the current time. The second reference value will be described later.

The rotation determination unit 112 causes the drive circuit 130 to output a current difference detection pulse for detecting a magnetic flux density difference generated by the stop angle of the magnet when the rotor 61 rotates or does not rotate by the current difference flowing through the coil 63, detects the coil current I1 when the current difference detection pulse is supplied, and determines whether the rotor 61 rotates or not based on the current difference flowing through the coil 63. When the rotor 61 rotates, the magnetic field generated by the current difference detection pulse is generated in a direction in which the magnetic field generated by the magnet is weakened, and therefore the magnetic field H obtained by adding the two falls within a region in which the influence of magnetic saturation is relatively small, and the slope dB/dH of the tangent to the BH characteristic becomes relatively large. Since the slope dB/dH of the tangent line becomes the differential permeability μ and the inductance of the coil 63 is proportional to the differential permeability μ, the inductance has a relatively large value. Therefore, the coil current I1 when the current difference detection pulse is supplied has a relatively low value. When the peak value of the coil current I1 is equal to or less than the threshold value, the rotation determination unit 112 determines that the rotor 61 is rotating.

The width of the current difference detection pulse is preferably in the range of 0.01 msec to 1 msec, and more preferably in the range of 0.05 msec to 0.1 msec. In the relative relationship with the width of the drive pulse, the width of the current difference detection pulse is preferably in the range of 1/3 to 1/300, more preferably in the range of 1/30 to 1/60, of the width of the drive pulse. These values are significant in that the accuracy of rotation detection is deteriorated if the current difference detection pulse is too short, and the rotor 61 is moved if it is too long. Further, details of a rotation detection method for detecting whether or not the rotor 61 is rotated are disclosed in japanese patent laid-open No. 2017-173037.

When the rotation determining unit 112 determines that the rotor 61 is not rotating, the magnetic sensor control unit 113 turns ON (ON) the magnetic sensor 150, and the magnetic sensor 150 acquires the intensity of the magnetic field. When the magnetism determination unit 114 determines that the intensity of the magnetic field is smaller than the second reference value, the magnetic sensor control unit 113 turns off the magnetic sensor 150.

The magnetism determination unit 114 determines whether or not the magnetic field strength acquired by the magnetic sensor control unit 113 is equal to or greater than a first reference value. The magnetism determination unit 114 determines whether or not the intensity of the magnetic field obtained by the magnetic sensor control unit 113 is smaller than a second reference value smaller than the first reference value. The first reference value is an upper limit value of the magnetic field strength at which the rotor 61 can rotate if the first to third stepping motors 120a to 120c are output correction pulses stronger than the drive pulses. The second reference value is a value smaller than the upper limit value of the magnetic field strength at which the rotor 61 can rotate if the drive pulses are output to the first to third stepping motors 120a to 120 c.

The timer 115 counts a period during which the rotation of the rotor 61 is stopped. The timer unit 115 counts the period during which the rotation of the rotor 61 is stopped when the magnetic field strength is determined to be equal to or greater than the first reference value by the magnetic determination unit 114, adds the periods of stopping, and stores the added periods in the RAM. When the rotation determination unit 112 determines that the rotor 61 is not rotating when the correction pulse is applied from the drive circuit 130, the non-rotating periods are counted, and the periods of stoppage are added and stored in the RAM.

Next, the needle travel control process executed by the pointer driving device 100 having the above-described configuration will be described.

In response to an instruction to start the process by the user, the pointer driving apparatus 100 starts the course control process shown in fig. 4. Next, a needle travel control process performed by the pointer driving device 100 will be described with reference to a flowchart. In the initial state, the magnetic sensor 150 is set to off, and the intensity of the magnetic field is not measured. The positions of the hands 20a to 20c are adjusted to the current time by the user via the crown 42.

When the needle feed control process is started, first, a first needle feed process is executed (step S101). When the first needle-passing process shown in fig. 5 is executed, the hand control unit 111 controls the drive circuit 130 to output a drive pulse to the coils 63 of the first to third stepping motors 120a to 120c once a second (step S201). Next, the rotation determination unit 112 controls the drive circuit 130 and outputs a current difference detection pulse to the coil 63 (step S202). Next, the rotation determination unit 112 detects the coil current I1 when the current difference detection pulse is supplied (step S203). Thereafter, the process returns to the stitch control process shown in fig. 4.

Next, the rotation determination unit 112 determines whether the rotor 61 is rotating or not based on the coil current I1 when the detected supply current difference detection pulse is generated (step S102). When the rotation determining unit 112 determines that the rotor 61 is rotating (yes in step S102), the process returns to step S101, and step S101 and step S102 are repeated.

When the rotation determination unit 112 determines that the rotor 61 is not rotating (no in step S102), the magnetic sensor control unit 113 turns on the magnetic sensor 150 and obtains the intensity of the magnetic field by the magnetic sensor 150 (step S103). Next, the timer unit 115 starts the timing of the period during which the rotation of the rotor 61 is stopped (step S104).

Next, the magnetism determination unit 114 determines whether or not the magnetic field strength acquired by the magnetic sensor control unit 113 is equal to or greater than a first reference value (step S105). The first reference value is an upper limit value of the magnetic field strength at which the rotor 61 can rotate if the first to third stepping motors 120a to 120c are output correction pulses stronger than the drive pulses. When the magnetism determination unit 114 determines that the magnetic field strength acquired by the magnetic sensor control unit 113 is not equal to or greater than the first reference value (no in step S105), the second course processing is executed (step S106).

When the second stitch processing shown in fig. 6 is executed, the hand control unit 111 controls the drive circuit 130 to output a correction pulse stronger than the drive pulse to the coils 63 of the first to third stepping motors 120a to 120c (step S301). The correction pulse is a pulse having at least either one of an applied voltage and a pulse width larger than the drive pulse. Next, the rotation determination unit 112 controls the drive circuit 130 and outputs a current difference detection pulse to the coil 63 (step S302). Next, the rotation determination unit 112 detects the coil current I1 when the current difference detection pulse is supplied (step S303). Next, the rotation determination unit 112 determines whether the rotor 61 is rotating or not based on the coil current I1 when the detected supply current difference detection pulse is generated (step S304).

When the rotation determination unit 112 determines that the rotor 61 is rotating (yes in step S304), the process returns to the needle travel control process shown in fig. 4. When the rotation determination unit 112 determines that the rotor 61 is not rotating (no in step S304), the timer unit 115 adds up the periods during which the rotation of the rotor 61 is stopped and stores the added periods in the RAM (step S305), and returns to the course control process.

When the magnetism determination unit 114 determines that the magnetic field strength acquired by the magnetic sensor control unit 113 is equal to or greater than the first reference value (yes in step S105), the time counting unit 115 adds up the periods during which the rotation of the rotor 61 is stopped and stores the added periods in the RAM (step S107).

Next, the magnetism determination unit 114 determines whether or not the magnetic field strength acquired by the magnetic sensor control unit 113 is smaller than a second reference value smaller than the first reference value (step S108). If it is determined that the magnetic field strength is not less than the second reference value (step S108: NO), the process returns to step S105, and steps S105 to S108 are repeated.

When it is determined that the magnetic field strength is less than the second reference value (yes in step S108), the hand control unit 111 controls the drive circuit 130 to drive the first to third stepping motors 120a to 120c based on the period of time during which the rotation of the rotor 61 is stopped, which is measured by the time measuring unit 115 (step S109). Thereby, the positions of the hands 20a to 20c are returned to the positions indicating the current time. For example, as shown in fig. 7, when the rotation of the hand 20a is stopped for 20 seconds by the magnetic field, the timer unit 115 counts the period during which the rotation of the rotor 61 is stopped for 20 seconds. Then, the pointer control unit 111 controls the drive circuit 130 to drive the first to third stepping motors 120a to advance the pointer 20a for 20 seconds. As a result, the pointer 20a returns to the position indicating the current time. The pointers 20b and 20c are also returned to the positions indicating the current time. Next, the magnetic sensor control unit 113 turns off the magnetic sensor 150 and stops the measurement of the intensity of the magnetic field (step S110). Then, returning to step S101, step S101 to step S110 are repeated.

For example, japanese patent application publication No. 2019-49436 discloses an electronic timepiece including: the stepping motor includes a rotor, a stator, a coil in which a lead wire is wound around a coil winding core, and a magnetic shield plate covering at least a part of the stepping motor. In the movement of the electronic timepiece disclosed in reference 1, when a strong magnetic field is applied, the stepping motor may be affected by the magnetic field from a portion not covered by the magnetic shield plate, and the rotation of the rotor may be stopped. Depending on the magnitude of the external magnetic field, the pointer may not be operated even when a pulse is output, and in such a case, there is a problem that power consumption increases due to the correction pulse being output a plurality of times.

In addition, a configuration is also conceivable in which a magnetic sensor is mounted on an electronic timepiece and an external magnetic field is measured by the magnetic sensor, so that a pulse is not output depending on the magnitude of the external magnetic field.

However, according to the pointer driving device 100 of the present embodiment, the magnetic sensor 150 is set to be off in the initial state, and the magnetic sensor control unit 113 turns on the magnetic sensor 150 when the rotation determination unit 112 determines that the rotor 61 is not rotating. Accordingly, when the rotor 61 is normally rotated, the magnetic sensor 150 is turned off, and thus power consumption can be reduced. When it is determined that the magnetic field intensity obtained by the magnetic sensor 150 is equal to or greater than the first reference value, the power consumption can be reduced even under the influence of the magnetic field by not outputting the correction pulse to the first to third stepping motors 120a to 120 c. When it is determined that the magnetic field intensity obtained by the magnetic sensor 150 is smaller than the first reference value, the correction pulses stronger than the drive pulses are output to the first to third stepping motors 120a to 120c, whereby accurate timing can be indicated even under the influence of the magnetic field. When it is determined that the magnetic field intensity acquired by the magnetic sensor 150 is smaller than the second reference value, the positions of the hands 20a to 20c are returned to the positions indicating the current time based on the period during which the rotation of the rotor 61 is stopped, which is measured by the time measuring unit 115. This makes it possible to indicate an accurate time even when the magnetic field influences the time. When it is determined that the magnetic field intensity acquired by the magnetic sensor 150 is less than the second reference value, the magnetic sensor 150 is turned off, and power consumption can be reduced. Therefore, the pointer driving apparatus 100 can reduce power consumption even if it is affected by a magnetic field.

(modification example)

In the above-described embodiment, the example in which the positions of the hands 20a to 20c are returned to the positions indicating the current time based on the period in which the rotation of the rotor 61 is stopped, which is counted by the timer unit 115, has been described. If the period during which the rotor 61 is stopped becomes long, the positions of the hands 20a to 20c may not return to the positions indicating the current time even if the rotor 61 is rotated based on the period during which the rotation of the rotor 61 is stopped. When the period of time during which the rotation of the rotor 61 is stopped, which is measured by the time measuring unit 115, is equal to or longer than the reference period, the first to third stepping motors 120a to 120c may be controlled so that the positions of the hands 20a to 20c are reset to the initial positions (moved to a certain position) and the positions of the hands 20a to 20c are adjusted to the positions indicating the current time. In this case, as shown in fig. 8, the pointer driving device 100 includes: a gear 21a that rotates the shaft of the hand 20a as the second hand: and a detection unit 22a that detects the position of the gear 21 a. The gear 21a includes a detection hole 23a and is rotated by the first stepping motor 120 a. The detection portion 22a detects the light passing through the detection hole 23a, thereby detecting the initial position of the gear 21 a. When it is determined that the period of time during which the rotation of the rotor 61 is stopped, which is measured by the time measuring unit 115, is equal to or longer than the reference period, the first stepping motor 120a rotates the gear 21a to a position at which the detection hole 23a is detected by the detection unit 22 a. Thereby, the gear 21a is reset to the initial position. The hand control unit 111 controls the first stepping motor 120a from this position, and adjusts the hand 20a to a position indicating the current time measured by the timer circuit 140. The pointer 20b and the pointer 20c are also adjusted to indicate the position of the current time by the same operation.

In the above-described embodiment, the example in which the rotation of the first to third stepping motors 120a to 120c is controlled to be stopped when it is determined that the magnetic field intensity acquired by the magnetic sensor 150 is equal to or greater than the first reference value has been described. The magnetic field intensity obtained by the magnetic sensor 150 may be used for a purpose other than stopping the rotation of the first to third stepping motors 120a to 120 c. For example, as shown in fig. 9, when it is determined that the magnetic field intensity acquired by the magnetic sensor 150 is equal to or greater than the third reference value, it may be reported to the user that a strong magnetic field is applied. The third reference value is a value at which there is a possibility that an abnormality such as a failure may occur in the electronic timepiece 1. In this case, the electronic timepiece 1 may include a display unit 70 for displaying characters and the like by liquid crystal display or the like, and the control unit 110 may cause the display unit 70 to display an error display indicating that a strong magnetic field is applied. An example of an error display is "mag. In this case, the third reference value may be set to a value larger than the first reference value. The user can determine whether maintenance is necessary or not by observing the error display. When it is determined that the magnetic field intensity acquired by the magnetic sensor 150 is equal to or greater than the third reference value, it may be notified to the user by sound such as a buzzer or vibration. In this case, the third reference value may be set to a value equal to or smaller than the first reference value. This allows the user to know the influence of the magnetic field applied to the electronic timepiece 1 and to move the electronic timepiece 1 to a place where the magnetic field is not influenced.

In the above-described embodiment, an example has been described in which when it is determined that the magnetic field strength is smaller than the first reference value, a correction pulse stronger than the drive pulse is output. The pointer control unit 111 may change at least 1 of the applied voltage and the pulse width of the correction pulse in stages according to the magnetic field intensity obtained by the magnetic sensor 150.

In the above-described embodiment, the rotation determination unit 112 has been described as an example of determining whether or not the rotor 61 of the first to third stepping motors 120a to 120c is rotating by outputting a current difference detection pulse to the coil 63 and detecting the coil current I1. The rotation determination unit 112 may be a potentiometer that converts a rotation angle into an electrical signal such as a voltage and outputs the electrical signal, as long as it can determine whether or not the rotor 61 of the first to third stepping motors 120a to 120c is rotated. An optical rotation detection device may be used that irradiates a rotating body such as a rotating shaft that rotates with the rotation of the rotor 61 with light and detects the reflected light reflected by the rotating body to detect the rotation.

In the above embodiment, the example in which the hands 20a to 20c are driven by the first to third stepping motors 120a to 120c, respectively, has been described, but the hands 20a to 20c may be driven by 1 stepping motor. In this case, the adjustment is performed by the plurality of gears such that the hand 20b as the minute hand rotates 1 turn when the hand 20a as the second hand rotates 60 turns, and the hand 20c as the hour hand rotates 1 turn when the hand 20b as the minute hand rotates 12 turns.

In the above embodiment, the example in which the hands 20a to 20c are driven by the first to third stepping motors 120a to 120c has been described, but the hands 20a to 20c may be driven by a motor other than a stepping motor such as a servo motor as long as they are driven to positions indicating the time. In this case, when it is determined that the magnetic field strength acquired by the magnetic sensor 150 is equal to or less than the first reference value, the motor may be rotated by a larger current or voltage.

In the above embodiment, an example has been described in which the hand 20a is a second hand indicating seconds, the hand 20b is a minute hand indicating minutes, and the hand 20c is an hour hand indicating time. The hands 20a to 20c may be hands other than time, and may indicate temperature, air pressure, orientation, and the like.

The pointer driving device 100 including a CPU, a RAM, a ROM, and the like can execute a part that becomes a center of the execution of the needle travel control process without depending on a dedicated system, using a general information portable terminal (a smartphone, a tablet PC), a personal computer, or the like. For example, the information terminal may be configured to execute the above-described processing by storing and distributing a computer program for executing the above-described operation in a computer-readable recording medium (a flexible disk, a CD-ROM (compact disc read only memory), a DVD-ROM (digital versatile disc read only memory), or the like), and installing the computer program in the information portable terminal or the like. The computer program may be stored in a storage device included in a server device on a communication network such as the internet, and the information processing device may be configured by downloading or the like from a general information processing terminal or the like.

Note that, the pointer driving apparatus 100 may store only the application part in the recording medium or the storage device when the pointer driving apparatus is realized by sharing the OS (operating system) and the application program or by cooperation of the OS and the application program.

Further, the computer program may be distributed via a communication network by being superimposed on a carrier wave. For example, the computer program may be distributed via a network by being posted on a Bulletin Board (BBS) on a communication network. The above-described processing may be executed by starting the computer program and executing the computer program under the control of the OS in the same manner as other application programs.

Although the preferred embodiments have been described above, the present invention is not limited to the specific embodiments, and the invention includes the inventions described in the claims and their equivalent ranges.