JP2019152650A - Stepping motor control device, timepiece and stepping motor control method for timepiece - Google Patents

Abstract

To ensure responsiveness for inversion by energy according to a rotation state upon inversion control of a stepping motor.SOLUTION: A stepping motor control device comprises: a rotation detecting unit for detecting a rotation state of a rotor of a stepping motor, which rotates a pointer, after output of a drive pulse to the stepping motor; and a control unit for performing control so as to inversely driving the pointer by at least a first pulse and a second pulse having different polarity from that of the first pulse, as drive pulses. The control unit outputs a plurality of first pulses different in energy from one another, as a plurality of test pulses, before outputting the first pulse, causes the rotation detecting unit to detect a rotation state of the rotor by the test pulses after outputting the plurality of test pulses and setting a test pulse corresponding to the detected rotation state as the first pulse to control the pointer so as to be inversely driven by using the set first pulse and second pulse at least.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a stepping motor control device, a timepiece, and a stepping motor control method for a timepiece.

  In the case of driving a stepping motor used for timepiece driving of a watch with one coil, there is an advantage in that current consumption can be reduced in forward rotation driving. It is necessary to rotate using one to two or more reverse pulses. In the reverse rotation using such a reaction, the rotor is vibrated rapidly in the opposite direction, so that the operational stability is likely to be affected by manufacturing variations and voltages. As a countermeasure, it is known to use a braking pulse after reverse rotation. However, there is a situation that the entire length of the pulse is increased by the braking pulse. Since the frequency at the time of reverse rotation is limited due to an increase in the total length of the pulse, the range of expression by the needle movement can be limited.

Japanese Patent Application Laid-Open No. H10-228688 describes that in reverse rotation driving, the first pulse length is changed according to the power supply voltage. By the way, in the technique described in Patent Document 1, measures against factors other than voltage are not considered.
Patent Document 2 describes that a reverse swing pulse that is pulled in the reverse direction is provided before the first to third pulses of the reverse drive pulse. By the way, in the technique described in Patent Document 2, high-speed driving at a high frequency can be limited.
Patent Document 3 describes that the rank of the subsequent reverse rotation pulse is determined by detecting the normal rotation state. By the way, in the technique of the second embodiment of Patent Document 3, when determining the reverse rotation pulse, the rotor must be rotated forward by one step in order to detect the normal rotation state in advance. Therefore, the technique of the second embodiment of Patent Document 3 is not sufficient in terms of immediacy and responsiveness to an instruction when starting a reverse pulse.

JP 55-59375 A JP 2014-117028 A JP 2014-196986 A

  In view of the above-described problems, the present invention provides a stepping motor control device, timepiece, and timepiece stepping motor control method capable of ensuring responsiveness when reverse rotation is desired by energy according to the rotation state in reverse rotation control of a stepping motor. The purpose is to provide.

  A stepping motor control device according to an aspect of the present invention includes a rotation detection unit that detects a rotation state of a rotor of the stepping motor after outputting a driving pulse to a stepping motor that rotates a pointer, and at least a first pulse as the driving pulse. And a second pulse having a polarity different from that of the first pulse, the control unit controlling to reversely drive the pointer, before outputting the first pulse, a plurality of first pulses having different energies from each other. A plurality of test pulses are output, and after the output of each of the plurality of test pulses, the rotation detection unit detects the rotation state of the rotor by the test pulse, and the test pulse corresponding to the detected rotation state is output to the first pulse. Set as a pulse, and at least using the set first pulse and the second pulse And a control unit for controlling to reverse drive.

  In the stepping motor control device according to one aspect of the present invention, the plurality of test pulses are continuously output so that the pulses having the largest energy are sequentially from the pulses having the smallest energy, and the control unit rotates the pointer forward. A test pulse corresponding to the predetermined amount of energy that is less than the energy required for the predetermined amount of energy may be set as the first pulse.

  In the stepping motor control device according to one aspect of the present invention, the control unit determines that the rotor has the predetermined amount of energy when an induced voltage generated with application of the test pulse is greater than a reference threshold voltage. The test pulse may be set as the first pulse.

  In the stepping motor control device according to one aspect of the present invention, the control unit, when the required time from the application time point of the test pulse to the time point when the induced voltage greater than the reference threshold voltage is generated is greater than or equal to the determination period, The rotor may determine the predetermined amount of energy and set the test pulse as the first pulse.

  A stepping motor control device according to an aspect of the present invention includes a stator capable of forming a magnetic path with the rotor, and a drive coil capable of forming a magnetic path in the stator, and the control unit includes: The plurality of test pulses may be output so that all of the plurality of test pulses are generated by one polarity of the magnetic path.

  The timepiece according to one aspect of the present invention may include the stepping motor control device and the hands.

  In the stepping motor control method for a timepiece according to one aspect of the present invention, a plurality of first pulses having different energies are used as a plurality of test pulses before outputting the first pulse as a driving pulse to the stepping motor for rotating the hands. A step of outputting, a step of detecting a rotation state of the rotor by the test pulse after each of the plurality of test pulses is output, a step of setting a test pulse corresponding to the detected rotation state as the first pulse, And rotating the pointer in reverse using at least the set first pulse and the second pulse having a polarity different from that of the first pulse.

  The stepping motor control method for a timepiece according to one aspect of the present invention applies a first forward drive pulse having a pulse length that does not allow the stepping motor to perform a predetermined forward rotation to the stepping motor when the stepping motor starts reverse rotation. And determining whether or not the stepping motor has performed a predetermined normal rotation by applying the first normal rotation driving pulse, and causing the stepping motor to perform a predetermined normal rotation by applying the first normal rotation driving pulse. If not, a second forward rotation drive pulse obtained by adding pulse energy to the first forward rotation drive pulse is applied to the stepping motor, and the stepping motor is applied by applying the second forward rotation drive pulse. It is determined whether the motor has performed a predetermined forward rotation, and the stepping is performed by applying the second forward rotation driving pulse. When the motor rotates in the predetermined forward direction, the pulse length of the reverse drive pulse is determined based on the pulse length of the second forward drive pulse, and the pulse energy is increased until the stepping motor performs the predetermined forward rotation. And the determination of whether or not the stepping motor has performed a predetermined forward rotation is repeated by applying the forward rotation driving pulse after the addition.

  In the stepping motor control method for a timepiece according to one aspect of the present invention, the forward rotation driving pulse is repeatedly applied until the stepping motor performs a predetermined forward rotation, and the stepping motor performs the predetermined forward rotation. The application of the reverse drive pulse may not be performed.

  In the timepiece stepping motor control method according to one aspect of the present invention, when the induced voltage generated in response to the application of the first forward rotation driving pulse is larger than a reference threshold voltage, the predetermined forward rotation is determined. Also good.

  In the timepiece stepping motor control method according to the aspect of the present invention, when the required time from the application time point of the first forward rotation drive pulse to the time point when the induced voltage greater than the reference threshold voltage is generated is equal to or longer than the determination period, The predetermined forward rotation may be determined.

  In the stepping motor control device according to one aspect of the present invention, the energy of the first test pulse of the plurality of test pulses that are continuously output is supplied to the stepping motor at a timing immediately before the first test pulse is output. It is the energy of the output drive pulse.

  In the stepping motor control device according to one aspect of the present invention, the polarity of at least one test pulse among the plurality of test pulses output continuously is different from the polarity of the other test pulses.

  In the stepping motor control device according to one aspect of the present invention, the time from the application of the test pulse to the application of the next test pulse is 15 ms or more.

  In the stepping motor control device according to one aspect of the present invention, when the energy of the test pulse is equal to or greater than a predetermined value and the induced voltage generated with the application of the test pulse is not greater than a reference threshold voltage, A first pulse, the second pulse, and a third pulse having a predetermined energy and the same polarity as the first pulse are applied to the stepping motor.

  In the stepping motor control device according to one aspect of the present invention, when the pulse length of the first pulse set by the control unit is within a predetermined range, the first pulse and the second pulse are used. When the pulse length of the first pulse that is driven and set by the control unit is out of the predetermined range, the energy of the first pulse, the second pulse, and the energy is predetermined energy. Driven by a third pulse having the same polarity as the first pulse.

  According to the present invention, it is possible to provide a stepping motor control device, a timepiece, and a timepiece stepping motor control method capable of ensuring responsiveness when it is desired to reverse the rotation by energy according to the rotation state in the reverse rotation control of the stepping motor. it can.

It is a figure which shows an example of schematic structure of the timepiece of 1st Embodiment. It is a figure which shows an example of a structure of the stepping motor shown in FIG. It is a figure for demonstrating the general method which reversely drives a stepping motor. It is a figure for demonstrating the problem of the example shown to FIG. 3 (A). 6 is a flowchart for explaining an example of processing (reverse rotation preparation processing) such as optimization of the length of the drive pulse P1 executed by the timepiece of the first embodiment. It is a time chart for demonstrating an example in which the process shown in FIG. 5 is performed by the timepiece of 1st Embodiment. It is a time chart for demonstrating the other example in which the process shown in FIG. 5 is performed by the timepiece of 1st Embodiment. It is a flowchart for demonstrating an example of processes (reverse rotation preparation process), such as optimization of the length of the drive pulse P1 performed with the timepiece of 2nd Embodiment. It is a time chart for demonstrating an example in which the process shown in FIG. 8 is performed by the timepiece of 2nd Embodiment. It is a time chart for demonstrating the other example in which the process shown in FIG. 8 is performed by the timepiece of 2nd Embodiment.

  Embodiments of a stepping motor control device, a timepiece, and a timepiece stepping motor control method according to the present invention will be described below with reference to the drawings.

<First Embodiment>
FIG. 1 is a diagram illustrating an example of a schematic configuration of a timepiece 1 according to the first embodiment.
In the example shown in FIG. 1, the watch 1 includes a battery 101, a stepping motor control device 102, a stepping motor 103, a watch case 112, an analog display unit 113, a movement 114, a hand 115, and a calendar display unit 116. And.
The battery 101 supplies power to the stepping motor control device 102 and the like. The stepping motor control device 102 controls the stepping motor 103. The stepping motor control device 102 includes an oscillation circuit 104, a frequency dividing circuit 105, a control circuit 106, a normal rotation drive pulse generation circuit 107, a reverse rotation drive pulse generation circuit 108, a motor drive circuit 109, and a normal rotation drive rotation. A detection circuit 110 and a reverse drive control circuit 111 are provided.
The oscillation circuit 104 generates a signal having a predetermined frequency. The frequency dividing circuit 105 divides the signal generated by the oscillation circuit 104 to generate a clock signal that serves as a time reference. The control circuit 106 performs control of each electronic circuit element constituting the electronic timepiece, control of change of the drive pulse, and the like based on the timepiece signal generated by the frequency divider circuit 105.

The normal rotation drive pulse generation circuit 107 generates a normal rotation drive pulse for driving the stepping motor 103 in the normal rotation based on the control signal generated by the control circuit 106. Specifically, the forward drive pulse generation circuit 107 can generate a main drive pulse and an auxiliary drive pulse having a driving force larger than that of the main drive pulse based on the control signal generated by the control circuit 106.
The reverse drive pulse generation circuit 108 generates a reverse drive pulse for driving the stepping motor 103 in the reverse direction based on the control signal generated by the control circuit 106.
The motor drive circuit 109 drives the stepping motor 103 by applying the forward drive pulse generated by the forward drive pulse generation circuit 107 or the reverse drive pulse generated by the reverse drive pulse generation circuit 108.
The forward drive rotation detection circuit 110 detects an induced voltage VRs generated by free vibration of the rotor 202 (see FIG. 2) of the stepping motor 103 after the stepping motor 103 causes the magnetic force generated by the drive pulse to act on the rotor 202. Thus, the rotation state of the stepping motor 103 is detected. Specifically, the forward rotation drive rotation detection circuit 110 performs stepping according to the time when the induced voltage VRs is greater than the reference threshold voltage Vcomp, or when the induced voltage VRs is less than or equal to the reference threshold voltage Vcomp. The rotation state of the motor 103 can be determined. Further, the forward rotation drive rotation detection circuit 110 outputs the rotation detection signal Vs to the control circuit 106 when the induced voltage VRs is larger than the reference threshold voltage Vcomp.
The reverse drive control circuit 111 outputs to the control circuit 106 a reverse drive control signal indicating the degree of margin for reverse drive.

FIG. 2 is a diagram showing an example of the configuration of the stepping motor 103 shown in FIG.
In the example shown in FIG. 2, the stepping motor 103 includes a stator 201, a rotor 202, a rotor accommodating through-hole 203, notches (inner notches) 204 and 205, and notches (outer notches) 206 and 207. A magnetic core 208, a drive coil 209, and saturable portions 210 and 211.
The stator 201 is made of a magnetic material. The stator 201 is formed with a rotor accommodating through hole 203 for accommodating the rotor 202. The rotor accommodating through hole 203 includes notches (inner notches) 204 and 205.
The stator 201 has notches 206 and 207 formed therein. A saturable portion 210 is provided between the rotor accommodating through hole 203 and the cutout portion 206. A saturable portion 211 is provided between the rotor accommodating through hole 203 and the cutout portion 207.
The rotor 202 is magnetized to two poles (specifically, S pole and N pole). The rotor 202 is disposed in the rotor accommodating through hole 203 so as to be rotatable with respect to the stator 201. The notches 204 and 205 constitute a positioning part for determining the stop position of the rotor 202 with respect to the stator 201.
The magnetic core 208 is joined to the stator 201. The magnetic core 208 and the stator 201 are fixed to a ground plate (not shown). The drive coil 209 is wound around the magnetic core 208. The first terminal OUT1 is one terminal of the drive coil 209, and the second terminal OUT2 is the other terminal of the drive coil 209.
The saturable portions 210 and 211 are configured so as not to be magnetically saturated by the magnetic flux of the rotor 202 but to be magnetically saturated when the drive coil 209 is excited to increase the magnetic resistance. That is, the magnetic path can be formed between the stator 201 and the rotor 202. The magnetic path can be formed in the stator 201 by the drive coil 209.

For example, in a state where the drive coil 209 is not excited, as shown in FIG. 2, the rotor 202 is arranged so that the line segment connecting the notch 204 and the notch 205 is perpendicular to the magnetic pole axis A of the rotor 202. Stops stably with respect to the stator 201.
For example, when the motor drive circuit 109 supplies a drive pulse between the first terminal OUT1 and the second terminal OUT2 of the drive coil 209 and the current i indicated by the solid line arrow in FIG. A magnetic flux indicated by a broken-line arrow is generated. As a result, the saturable portions 210 and 211 are saturated and the magnetic resistance is increased, and then the rotor 202 is rotated 180 degrees counterclockwise in FIG. 2 due to the interaction between the magnetic pole generated in the stator 201 and the magnetic pole of the rotor 202. Rotates and stops stably. By the rotation of about 180 degrees, the pointer 115 of the timepiece 1 can move a predetermined amount of one scale. The prescribed amount of operation may be referred to as one step. A wheel train having an appropriate reduction ratio is appropriately disposed between the rotor 202 and the pointer 115 so as to achieve the specified amount of operation.
With the rotor 202 rotated approximately 180 degrees from the state shown in FIG. 2, the motor drive circuit 109 supplies a drive pulse of reverse polarity between the first terminal OUT1 and the second terminal OUT2 of the drive coil 209, and the current i When a current in the opposite direction flows, a magnetic flux in the direction opposite to the dashed arrow is generated in the stator 201. As a result, the saturable portions 210 and 211 are saturated first, and then the rotor 202 rotates 180 degrees counterclockwise in FIG. 2 due to the interaction between the magnetic poles generated in the stator 201 and the magnetic poles of the rotor 202, and is stable. To stop.
In this way, by supplying signals with different polarities (alternating signals) to the drive coil 209, the rotor 202 continuously rotates approximately 180 degrees counterclockwise in FIG.

  Returning to the description of FIG. 1, the watch case 112 accommodates the battery 101, the stepping motor control device 102, the stepping motor 103, the analog display unit 113, the movement 114, the hands 115, and the calendar display unit 116. . The movement 114 is a machine body that includes a driving portion of the timepiece 1. The hands 115 and the calendar display unit 116 are driven by the stepping motor 103. The analog display unit 113 and the hands 115 display the time.

FIG. 3 is a diagram for explaining a general method for driving the stepping motor 103 in the reverse direction. Specifically, FIG. 3A shows an example of a general technique for reversing the stepping motor 103 by applying three drive pulses. FIG. 3B shows an example of a general technique for reversing the stepping motor 103 by applying two drive pulses.
In the example shown in FIG. 3A, first, a driving pulse (repulsion pulse) P <b> 1 that rotates the rotor 202 of the stepping motor 103 in the forward rotation direction is applied to the stepping motor 103. Next, a driving pulse (suction pulse) P <b> 2 that reversely rotates the rotor 202 of the stepping motor 103 is applied to the stepping motor 103. Next, the drive pulse P <b> 3 is applied to the stepping motor 103. As a result, the rotor 202 of the stepping motor 103 is reversed.
That is, in the example shown in FIG. 3A, the rotor 202 of the stepping motor 103 is once rotated in the normal rotation direction by the drive pulse P1. Next, the rotation is reversed by the drive pulse P2 and the drive pulse P3 by using the reaction of the rotation in the forward rotation direction.

In the example shown in FIG. 3B, first, a driving pulse (repulsion pulse) P <b> 1 that rotates the rotor 202 of the stepping motor 103 in the forward direction is applied to the stepping motor 103. Next, a driving pulse (suction pulse) P <b> 2 that reversely rotates the rotor 202 of the stepping motor 103 is applied to the stepping motor 103. As a result, the rotor 202 of the stepping motor 103 is reversed.
That is, in the example shown in FIG. 3B, the rotor 202 of the stepping motor 103 is once rotated in the normal rotation direction by the drive pulse P1. Next, the rotation is reversed by the drive pulse P2 using the reaction of the rotation in the normal rotation direction.
As shown in FIG. 3B, the reverse rotation of the rotor 202 of the stepping motor 103 is established only by the two drive pulses of the repulsion pulse P1 and the suction pulse P2. On the other hand, as a countermeasure against manufacturing variations and step-out due to a magnetic field, it is common to add a drive pulse P3 as shown in FIG. The drive pulse P3 acts as repulsion => suction.
Such a combination of drive pulses P1, P2, and P3 is hereinafter referred to as a reverse pulse or a reverse drive pulse. In addition, the reverse pulse or the reverse drive pulse can be constituted by only the drive pulses P1 and P2.

FIG. 4 is a diagram for explaining the problem of the example shown in FIG.
In FIG. 4, the vertical axis indicates the current consumption of the stepping motor 103. The horizontal axis indicates time. “IP1” indicates an instantaneous value of the current consumption of the stepping motor 103 accompanying the application of the drive pulse P1. “IP2” indicates an instantaneous value of the current consumption of the stepping motor 103 accompanying the application of the drive pulse P2. “IP3” indicates an instantaneous value of the current consumption of the stepping motor 103 accompanying the application of the drive pulse P3.
In the example shown in FIG. 4, the consumption current (integrated value) of the stepping motor 103 due to the application of the drive pulse P1 and the drive pulse P2 occupies 18% of the total consumption current. The current consumption (integrated value) of the stepping motor 103 accompanying the application of the drive pulse P3 occupies 82% of the total current consumption.
The required rotation time of the rotor 202 of the stepping motor 103 accompanying the application of the drive pulse P1 and the drive pulse P2 occupies 19% of the total required rotation time. The required rotation time of the rotor 202 of the stepping motor 103 accompanying the application of the drive pulse P3 occupies 81% of the total required rotation time.
As shown in FIG. 4, when the drive pulse P <b> 3 is applied, the entire required rotation time of the rotor 202 of the stepping motor 103 becomes long. That is, it may be difficult to speed up the reverse rotation of the rotor 202 of the stepping motor 103.
Further, when the drive pulse P3 is applied, the current consumption of the entire stepping motor 103 is increased. That is, it may be difficult to save power consumption for the reverse rotation of the rotor 202 of the stepping motor 103.

  In view of the above-described problems, the timepiece 1 of the first embodiment does not apply the drive pulse P3 (see FIG. 3A). In the timepiece 1 of the first embodiment, the length of the drive pulse P1 is optimized.

FIG. 5 is a flowchart for explaining an example of processing (reverse rotation preparation processing) such as optimization of the length of the drive pulse P1 executed by the timepiece 1 of the first embodiment.
In the example shown in FIG. 5, when the timepiece 1 of the first embodiment starts the reverse rotation preparation process (that is, when the stepping motor 103 starts reverse rotation), first, in step S11A, the motor drive circuit 109 A first forward drive pulse PF1a having a pulse length that does not cause forward rotation (forward rotation less than 180 ° rotation) is applied to the stepping motor 103.
Here, the relationship between predetermined normal rotation and normal rotation will be described. The predetermined forward rotation refers to a rotation state in which the direction of the magnetic pole of the rotor (arrow A in FIG. 2) does not exceed the position of the notch 205 (the notch 204 in the case of a drive pulse of reverse polarity). If the magnetic pole of the rotor exceeds the notch 205, the magnetic potential energy has exceeded the maximum position, and the rotor can be rotated up to about 180 degrees as it is. Such rotation exceeding the maximum potential energy point is referred to as normal rotation. As a result, the rotor can be rotated approximately 180 degrees, and the pointer can move one step. If the magnetic pole of the rotor cannot exceed the notch 205, the maximum potential energy point cannot be exceeded, and the rotor tries to return to the 0 degree position that is the start position before the drive pulse is applied.
Next, in step S11B, the normal rotation drive rotation detection circuit 110 detects the induced voltage VRs.
Next, in step S11C, the normal rotation drive rotation detection circuit 110 determines whether or not the induced voltage VRs is greater than the reference threshold voltage Vcomp.
If the induced voltage VRs is greater than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has performed a predetermined normal rotation by applying the first normal rotation driving pulse PF1a, and the process proceeds to step S11D. As described above, the pulse length of the first forward rotation driving pulse PF1a is set to a pulse length that does not allow the stepping motor 103 to perform the predetermined forward rotation. Therefore, in step S11C, if the induced voltage VRs is greater than the reference threshold voltage Vcomp, the normal rotation drive rotation detection circuit 110 does not determine.
When the induced voltage VRs is equal to or lower than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has not performed the predetermined normal rotation by applying the first normal rotation driving pulse PF1a, and the process proceeds to Step S12A.
In step S11D, the motor drive circuit 109 applies the first normal rotation drive pulse PF1a to the stepping motor 103 as the drive pulse (repulsion pulse) P1 described above. Next, the process proceeds to step S20.

In step S <b> 12 </ b> A, the motor drive circuit 109 applies a second normal rotation drive pulse PF <b> 1 b obtained by adding pulse energy to the first normal rotation drive pulse PF <b> 1 a to the stepping motor 103. This control is sometimes referred to as rank up.
Next, in step S12B, the normal rotation drive rotation detection circuit 110 detects the induced voltage VRs.
Next, in step S12C, the normal rotation drive rotation detection circuit 110 determines whether or not the induced voltage VRs is greater than the reference threshold voltage Vcomp.
If the induced voltage VRs is greater than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has performed a predetermined normal rotation by the application of the second normal rotation driving pulse PF1b, and the process proceeds to step S12D.
When the induced voltage VRs is equal to or lower than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has not performed the predetermined normal rotation by the application of the second normal rotation driving pulse PF1b, and the process proceeds to Step S13A.
In step S12D, the motor drive circuit 109 applies the second forward drive pulse PF1b to the stepping motor 103 as the drive pulse (repulsion pulse) P1 described above. Next, the process proceeds to step S20.

In step S13A, the motor drive circuit 109 applies the third forward drive pulse PF1c obtained by adding the pulse energy to the second forward drive pulse PF1b to the stepping motor 103 (rank up).
Next, in step S13B, the normal rotation drive rotation detection circuit 110 detects the induced voltage VRs.
Next, in step S13C, the normal rotation drive rotation detection circuit 110 determines whether or not the induced voltage VRs is greater than the reference threshold voltage Vcomp.
If the induced voltage VRs is greater than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has performed a predetermined normal rotation by the application of the third normal rotation driving pulse PF1c, and the process proceeds to step S13D.
When the induced voltage VRs is equal to or lower than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has not performed the predetermined normal rotation by the application of the third normal rotation driving pulse PF1c, and the process proceeds to step S14.
In step S <b> 13 </ b> D, the motor drive circuit 109 applies the third normal rotation drive pulse PF <b> 1 c to the stepping motor 103 as the drive pulse (repulsion pulse) P <b> 1 described above. Next, the process proceeds to step S20.

  In step S14, whether or not the stepping motor 103 has performed a predetermined normal rotation by adding pulse energy and applying a normal driving pulse after adding the pulse energy until the induced voltage VRs becomes larger than the reference threshold voltage Vcomp. The forward rotation drive pulse when the induced voltage VRs becomes larger than the reference threshold voltage Vcomp is applied to the stepping motor 103 as the drive pulse (repulsion pulse) P1 described above.

In step S20, the pulse length of the reverse drive pulse is determined based on the pulse length of the drive pulse when the induced voltage VRs becomes larger than the reference threshold voltage Vcomp.
Specifically, when it is determined in step S12C that the induced voltage VRs is greater than the reference threshold voltage Vcomp, the pulse length of the reverse drive pulse is determined based on the pulse length of the second forward drive pulse PF1b. .
For example, if it is determined in step S13C that the induced voltage VRs is greater than the reference threshold voltage Vcomp, the pulse length of the reverse drive pulse is determined based on the pulse length of the third normal drive pulse PF1c. The pulse length determined here is a predetermined amount of energy less than that required for normal rotation of the pointer.
In step S <b> 20, the motor drive circuit 109 applies the reverse drive pulse as the drive pulse (suction pulse) P <b> 2 described above to the stepping motor 103. As a result, as shown in FIG. 3B, the rotor 202 of the stepping motor 103 is reversed.

Specifically, in the example illustrated in FIG. 5, for example, when it is determined in step S13C that the induced voltage VRs is greater than the reference threshold voltage Vcomp, the stepping motor 103 performs a predetermined amount in the forward direction by the pulse energy in step S13A. It determines with having rotated, and drives to a normal rotation direction in step S13D by the energy equivalent to the said pulse energy. The predetermined amount refers to a state where the direction of the magnetic pole of the rotor (arrow A in FIG. 2) does not exceed the position of the notch 205 (the notch 204 in the case of a drive pulse of reverse polarity). The predetermined amount is the amount of rotation when the rotor is rotated by the energy corresponding to the predetermined forward rotation described above or the drive pulse having the energy.
Using the energy of the pulse as the drive pulse P1, at least the drive pulse P2 is set in step S20, a reverse pulse is set by a set of these drive pulses, and the stepping motor 103 is reversed.

  According to the example shown in FIG. 5, the stepping motor 103 can be reversely rotated by using a forward rotation driving pulse having a pulse length at which the stepping motor 103 rotates in a predetermined forward direction. As a result, the reverse rotation speed and power consumption of the stepping motor 103 can be realized.

FIG. 6 is a time chart for explaining an example in which the process shown in FIG. 5 is executed by the timepiece 1 of the first embodiment.
In the example shown in FIG. 6, step S <b> 11 </ b> A of FIG. 5 is executed at time t <b> 1, and the motor drive circuit 109 applies the first normal rotation drive pulse PF <b> 1 a to the stepping motor 103.
Next, before time t2, step S11B and step S11C in FIG. 5 are executed, the induced voltage VRs is equal to or lower than the reference threshold voltage Vcomp, and the stepping motor 103 is rotated in a predetermined normal rotation by application of the first normal rotation driving pulse PF1a. It is determined that they did not.

Next, at time t <b> 2, step S <b> 12 </ b> A in FIG. 5 is executed, and the motor drive circuit 109 applies the second normal rotation drive pulse PF <b> 1 b to the stepping motor 103.
Next, before time t3, steps S12B and S12C of FIG. 5 are executed, the induced voltage VRs is equal to or lower than the reference threshold voltage Vcomp, and the stepping motor 103 is rotated in a predetermined normal rotation by application of the second normal rotation driving pulse PF1b. It is determined that they did not.

Next, at time t <b> 3, step S <b> 13 </ b> A in FIG. 5 is executed, and the motor drive circuit 109 applies the third normal rotation drive pulse PF <b> 1 c to the stepping motor 103.
Next, at time t3A, step S13B and step S13C in FIG. 5 are executed, the induced voltage VRs is larger than the reference threshold voltage Vcomp, and the stepping motor 103 performs a predetermined normal rotation by application of the third normal rotation driving pulse PF1c. It is determined.

Next, at time t4, step S13D of FIG. 5 is executed, and the motor drive circuit 109 applies the third forward drive pulse PF1c to the stepping motor 103 as the drive pulse (repulsion pulse) P1 (see FIG. 3B). Apply.
Next, after time t5, step S20 of FIG. 5 is executed, and the reverse drive pulse whose pulse length is determined based on the pulse length of the third forward drive pulse PF1c is generated by the motor drive circuit 109 as a drive pulse (suction). Pulses P2 and P3 are applied to the stepping motor 103. As a result, the stepping motor 103 is reversed.

FIG. 7 is a time chart for explaining another example in which the process shown in FIG. 5 is executed by the timepiece 1 of the first embodiment.
In the example shown in FIG. 7, step S <b> 11 </ b> A of FIG. 5 is executed at time t <b> 11, and the motor drive circuit 109 applies the first normal rotation drive pulse PF <b> 1 a to the stepping motor 103.
Next, before time t12, step S11B and step S11C in FIG. 5 are executed, the induced voltage VRs is equal to or lower than the reference threshold voltage Vcomp, and the stepping motor 103 is rotated in a predetermined normal rotation by applying the first normal rotation driving pulse PF1a. It is determined that they did not.

Next, at time t <b> 12, step S <b> 12 </ b> A in FIG. 5 is executed, and the motor drive circuit 109 applies the second normal rotation drive pulse PF <b> 1 b to the stepping motor 103.
Next, before time t13, step S12B and step S12C of FIG. 5 are executed, the induced voltage VRs is equal to or lower than the reference threshold voltage Vcomp, and the stepping motor 103 is rotated in a predetermined normal rotation by applying the second normal rotation driving pulse PF1b. It is determined that they did not.

Next, at time t <b> 13, step S <b> 13 </ b> A in FIG. 5 is executed, and the motor drive circuit 109 applies the third normal rotation drive pulse PF <b> 1 c to the stepping motor 103.
Next, at time t13A, step S13B and step S13C in FIG. 5 are executed, the induced voltage VRs is greater than the reference threshold voltage Vcomp, and the stepping motor 103 performs predetermined forward rotation by application of the third forward rotation driving pulse PF1c. It is determined.

Next, at time t14, step S13D of FIG. 5 is executed, and the motor drive circuit 109 supplies the third forward rotation drive pulse PF1c to the stepping motor 103 as the drive pulse (repulsion pulse) P1 (see FIG. 3B). Apply.
Next, after time t15, step S20 in FIG. 5 is executed, and the reverse drive pulse whose pulse length is determined based on the pulse length of the third forward rotation drive pulse PF1c is generated by the motor drive circuit 109 as a drive pulse (suction). Pulse) P2 is applied to the stepping motor 103. As a result, the stepping motor 103 is reversed.
The difference between the example shown in FIG. 6 and the example shown in FIG. 7 is the presence or absence of the drive pulse P3. The present invention eliminates the need for the drive pulse P3 and enables reverse rotation only by the drive pulses P1 and P2. As a result, the pulse length required for the reverse rotation can be shortened, so that the reverse drive frequency can be further increased.

[Summary of First Embodiment]
As described above, in the timepiece 1 of the first embodiment, the drive pulses PF1a, PF1b, PF1c, and the like to the stepping motor 103 that rotates the hands 115 are output, for example, in steps S11A, S12A, S13A, etc. of FIG. In addition, after outputting the drive pulses PF1a, PF1b, PF1c, etc., the rotation state of the rotor 202 of the stepping motor 103 is detected in steps S11B, S12B, S13B, etc.
For example, in the example shown in FIGS. 5 and 6, before the third forward rotation driving pulse PF1c is output as the driving pulse (repulsion pulse) P1 (see FIG. 3B) in step S13D, step S11A and step S12A are performed. In step S13A, a plurality of normal rotation driving pulses PF1a, PF1b, and PF1c having different energies are output as a plurality of test pulses.
After the output of the test pulse PF1a, the rotation state of the rotor 202 by the test pulse PF1a is detected in step S11B. Further, after the output of the test pulse PF1b, in step S12B, the rotation state of the rotor 202 by the test pulse PF1b is detected. Further, after the output of the test pulse PF1c, the rotation state of the rotor 202 by the test pulse PF1c is detected in step S13B.
When rotation of the rotor 202 by the test pulse PF1c is detected in step S13B and step S13C, in step S13D, the test pulse PF1c in which the rotor 202 is rotated in a predetermined normal direction is set as the normal rotation drive pulse PF1c, The rolling drive pulse PF1c is output as a drive pulse (repulsion pulse) P1.
In step S20, reverse drive pulses having a polarity different from that of the forward drive pulse PF1c are output as drive pulses (suction pulses) P2 (see FIGS. 6 and 7) and P3 (see FIG. 6).
That is, in the example shown in FIGS. 5, 6, and 7, the pointer 115 is driven in reverse by the forward drive pulse PF1c output in step S13D and the reverse drive pulse output in step S20.
Therefore, according to the timepiece 1 of the first embodiment, in the reverse rotation control of the stepping motor 103, it is possible to ensure the responsiveness when it is desired to reverse the rotation by the energy corresponding to the rotation state. Specifically, in selecting the optimum energy of the drive pulse necessary for the reverse rotation, the selection can be made without rotating the rotor 202. Therefore, responsiveness at the start of reverse rotation can be ensured.

For example, in the example shown in FIGS. 5, 6, and 7, a plurality of test pulses PF1a, PF1b, and PF1c are continuously output so as to become pulses PF1c having higher energy in order from pulses PF1a having lower energy. Further, the test pulse PF1c corresponding to the energy of the rotation pulse that is less than the energy necessary for normal rotation of the pointer 115 and immediately before the rotor 202 reaches the rotation angle corresponding to the specified amount is forward-driven. The pulse PF1c is set and output in step S13D.
Specifically, when the induced voltage VRs generated with the application of the test pulse PF1c is larger than the reference threshold voltage Vcomp, the energy of the rotation pulse immediately before the rotor 202 reaches the rotation angle corresponding to the specified amount is determined. The test pulse PF1c is set as the normal rotation driving pulse PF1c.
Therefore, according to the timepiece 1 of the first embodiment, a pulse having energy larger than the test pulse PF1c (that is, energy larger than necessary) is set as the forward rotation drive pulse and is suppressed from being output. be able to.
For example, in the example shown in FIG. 6, the control circuit 106 generates all of the plurality of test pulses PF1a, PF1b, and PF1c with one polarity of the magnetic path (specifically, the upper polarity in FIG. 6). A plurality of test pulses PF1a, PF1b, and PF1c are output.

For example, in the example shown in FIG. 6, before the time t3A when it is detected that the stepping motor 103 has the minimum energy to form the reverse pulse, the test pulses such as the forward drive pulses PF1a, PF1b, and PF1c The application is repeated. Specifically, the forward rotation drive pulse PF1a is applied at time t1, the forward rotation drive pulse PF1b is applied at time t2, and the forward rotation drive pulse PF1c is applied at time t3. This is only an example, and the number of test pulses is continued until an induced voltage such as that at time t3A is detected.
The application of the reverse drive pulse is not performed before the time t3A when the stepping motor 103 performs the normal rotation. The application of the reverse drive pulse is performed at time t4.
Therefore, according to the timepiece 1 of the first embodiment, it is possible to suppress the possibility that the reverse drive pulse is applied unnecessarily before the time t3 when the reaction of the rotation in the forward rotation direction is insufficient.

Second Embodiment
Hereinafter, a stepping motor control device, a timepiece, and a stepping motor control method according to a second embodiment of the present invention will be described with reference to the drawings.
The timepiece 1 of the second embodiment is configured in the same manner as the timepiece 1 of the first embodiment described above, except for the points described below. Therefore, according to the timepiece 1 of the second embodiment, the same effects as those of the timepiece 1 of the first embodiment described above can be obtained except for the points described below.

FIG. 8 is a flowchart for explaining an example of processing (reverse rotation preparation processing) such as optimization of the length of the drive pulse P1 executed by the timepiece 1 of the second embodiment.
In the example shown in FIG. 8, when the timepiece 1 of the second embodiment starts the reverse rotation preparation process (that is, when the stepping motor 103 starts reverse rotation), first, in step S <b> 31 </ b> A, the motor drive circuit 109 A first forward drive pulse PF1a having a pulse length that does not cause forward rotation is applied to the stepping motor 103.
Next, in step S31B, the normal rotation drive rotation detection circuit 110 detects the induced voltage VRs after the first determination period has elapsed since the determination period Tcomp has elapsed since the application of the first normal rotation drive pulse PF1a. .
Next, in step S31C, the forward rotation detection detection circuit 110 determines whether or not the induced voltage VRs has become higher than the reference threshold voltage Vcomp after the first determination period has elapsed.
If the induced voltage VRs becomes larger than the reference threshold voltage Vcomp after the first determination period has elapsed, it is determined that the stepping motor 103 has performed a predetermined normal rotation by applying the first normal rotation driving pulse PF1a, and step Proceed to S31D. As described above, the pulse length of the first forward rotation driving pulse PF1a is set to a pulse length that does not allow the stepping motor 103 to perform the predetermined forward rotation. Therefore, in step S31C, the forward drive rotation detection circuit 110 does not determine that the induced voltage VRs has become larger than the reference threshold voltage Vcomp after the first determination period has elapsed.
If the induced voltage VRs does not become larger than the reference threshold voltage Vcomp after the first determination period has elapsed, it is determined that the stepping motor 103 has not performed the predetermined normal rotation by the application of the first normal rotation driving pulse PF1a. The process proceeds to step S32A.
In step S31D, the motor drive circuit 109 applies the first forward drive pulse PF1a to the stepping motor 103 as the drive pulse (repulsion pulse) P1 described above. Next, the process proceeds to step S40.

In step S32A, the motor drive circuit 109 applies to the stepping motor 103 the second forward rotation drive pulse PF1b obtained by adding the pulse energy to the first forward rotation drive pulse PF1a.
Next, in step S32B, the normal rotation drive rotation detection circuit 110 detects the induced voltage VRs after the second determination period has elapsed since the determination period Tcomp has elapsed since the application of the second normal rotation drive pulse PF1b. .
Next, in step S32C, the normal rotation drive rotation detection circuit 110 determines whether or not the induced voltage VRs has become larger than the reference threshold voltage Vcomp after the second determination period has elapsed.
If the induced voltage VRs becomes higher than the reference threshold voltage Vcomp after the second determination period has elapsed, it is determined that the stepping motor 103 has performed a predetermined normal rotation by applying the second normal rotation driving pulse PF1b, and step Proceed to S32D.
If the induced voltage VRs does not become higher than the reference threshold voltage Vcomp after the second determination period has elapsed, it is determined that the stepping motor 103 has not performed a predetermined normal rotation by the application of the second normal rotation driving pulse PF1b. The process proceeds to step S33A.
In step S32D, the motor drive circuit 109 applies the second normal rotation drive pulse PF1b to the stepping motor 103 as the drive pulse (repulsion pulse) P1 described above. Next, the process proceeds to step S40.

In step S33A, the motor drive circuit 109 applies to the stepping motor 103 a third normal rotation drive pulse PF1c obtained by adding pulse energy to the second normal rotation drive pulse PF1b.
Next, in step S33B, the normal rotation drive rotation detection circuit 110 detects the induced voltage VRs after the third determination period has elapsed since the determination period Tcomp has elapsed since the application of the third normal rotation drive pulse PF1c. .
Next, in step S33C, the normal rotation drive rotation detection circuit 110 determines whether or not the induced voltage VRs has become higher than the reference threshold voltage Vcomp after the third determination period has elapsed.
If the induced voltage VRs becomes greater than the reference threshold voltage Vcomp after the third determination period has elapsed, it is determined that the stepping motor 103 has performed a predetermined normal rotation by applying the third normal rotation driving pulse PF1c, and step Proceed to S33D.
If the induced voltage VRs does not become higher than the reference threshold voltage Vcomp after the third determination period has elapsed, it is determined that the stepping motor 103 has not performed the predetermined normal rotation by the application of the third normal rotation driving pulse PF1c. The process proceeds to step S34.
In step S33D, the motor drive circuit 109 applies the third forward drive pulse PF1c to the stepping motor 103 as the drive pulse (repulsion pulse) P1 described above. Next, the process proceeds to step S40.

  In step S34, the pulse energy is added until the induced voltage VRs becomes higher than the reference threshold voltage Vcomp after the determination period Tcomp elapses from the application time point of the forward rotation drive pulse, and the forward rotation after the pulse energy addition is performed. The determination of whether or not the stepping motor 103 has performed a predetermined forward rotation by applying the drive pulse is repeated, and the normal rotation drive pulse when the induced voltage VRs becomes larger than the reference threshold voltage Vcomp is the drive pulse described above. (Repulsion pulse) is applied to the stepping motor 103 as P1.

In step S40, the pulse length of the reverse drive pulse is determined based on the pulse length of the drive pulse when the induced voltage VRs becomes larger than the reference threshold voltage Vcomp.
Specifically, when it is determined in step S32C that the induced voltage VRs is greater than the reference threshold voltage Vcomp, the pulse length of the reverse drive pulse is determined based on the pulse length of the second forward drive pulse PF1b. The
For example, when it is determined in step S33C that the induced voltage VRs is greater than the reference threshold voltage Vcomp, the pulse length of the reverse drive pulse is determined based on the pulse length of the third forward drive pulse PF1c.
In step S <b> 40, the motor drive circuit 109 applies a reverse drive pulse as the drive pulse (suction pulse) P <b> 2 described above to the stepping motor 103. As a result, as shown in FIG. 3B, the rotor 202 of the stepping motor 103 is reversed.

In detail, in the example shown in FIG. 8, for example, when it is determined in step S33C that the induced voltage VRs is larger than the reference threshold voltage Vcomp, the stepping motor 103 performs a predetermined normal rotation by the pulse energy in step S33A. In step S33D, the motor is driven in the forward direction with energy equivalent to the pulse energy. As in the first embodiment, the predetermined forward rotation refers to the position of the notch 205 (the notch 204 in the case of a reverse polarity drive pulse) where the direction of the magnetic pole of the rotor (arrow A in FIG. 2) is the same. It refers to a state that does not exceed the limit. If the magnetic pole of the rotor exceeds the notch 205, it means that the position of the maximum magnetic potential energy is exceeded, and the rotor can be rotated forward to about 180 degrees as it is.
Using the energy of the pulse as the drive pulse P1, at least a drive pulse P2 is set in step S40, a reverse pulse is set by a set of these drive pulses, and the stepping motor 103 is rotated in reverse.

In the example shown in FIG. 8, when the required time from the application time of the test pulse to the time when the induced voltage VRs greater than the reference threshold voltage Vcomp is generated is equal to or longer than the determination period Tcomp, the rotor 202 corresponds to a predetermined forward rotation. The energy is determined and the test pulse is set as the drive pulse P1.
According to the example shown in FIG. 8, similarly to the example shown in FIG. 5, the stepping motor 103 can be rotated by a normal rotation driving pulse having a pulse length at which the stepping motor 103 performs a predetermined normal rotation. As a result, the reverse rotation speed and power consumption of the stepping motor 103 can be realized.

FIG. 9 is a time chart for explaining an example in which the process shown in FIG. 8 is executed by the timepiece 1 of the second embodiment.
In the example shown in FIG. 9, step S <b> 31 </ b> A of FIG. 8 is executed at time t <b> 21, and the motor drive circuit 109 applies the first normal rotation drive pulse PF <b> 1 a to the stepping motor 103.
Next, after the first determination period elapsed time t21A in which the determination period Tcomp elapses from the application time t21 of the first forward rotation driving pulse PF1a (specifically, the period from time t21A to time t22), step S31B in FIG. Since step S31C is executed and the induced voltage VRs has not become larger than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has not performed the predetermined normal rotation by the application of the first normal rotation driving pulse PF1a.

Next, at time t <b> 22, step S <b> 32 </ b> A in FIG. 8 is executed, and the motor drive circuit 109 applies the second normal rotation drive pulse PF <b> 1 b to the stepping motor 103.
Next, after the second determination period elapsed time t22A in which the determination period Tcomp elapses from the application time t22 of the second forward rotation driving pulse PF1b (specifically, the period from time t22A to time t23), step S32B in FIG. Since step S32C is executed and the induced voltage VRs has not become larger than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has not performed the predetermined normal rotation by the application of the second normal rotation driving pulse PF1b.

Next, at time t <b> 23, step S <b> 33 </ b> A of FIG. 8 is executed, and the motor drive circuit 109 applies the third normal rotation drive pulse PF <b> 1 c to the stepping motor 103.
Next, step S33B and step S33C of FIG. 8 are executed after the third determination period elapsed time t23A (specifically, time t23A) after the determination period Tcomp elapses from the application time t23 of the third normal rotation drive pulse PF1c. Since the induced voltage VRs is greater than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has performed a predetermined normal rotation by applying the third normal rotation driving pulse PF1c.

Next, at time t24, step S33D of FIG. 8 is executed, and the motor drive circuit 109 supplies the third forward rotation drive pulse PF1c to the stepping motor 103 as the drive pulse (repulsion pulse) P1 (see FIG. 3B). Apply.
Next, after time t25, step S40 in FIG. 8 is executed, and the reverse drive pulse whose pulse length is determined based on the pulse length of the third forward drive pulse PF1c is generated by the motor drive circuit 109 as a drive pulse (suction). Pulses P2 and P3 are applied to the stepping motor 103. As a result, the stepping motor 103 is reversed.

FIG. 10 is a time chart for explaining another example in which the process shown in FIG. 8 is executed by the timepiece 1 of the second embodiment.
In the example shown in FIG. 10, step S <b> 31 </ b> A of FIG. 8 is executed at time t <b> 31, and the motor drive circuit 109 applies the first normal rotation drive pulse PF <b> 1 a to the stepping motor 103.
Next, after the first determination period elapsed time t31A in which the determination period Tcomp elapses from the application time t31 of the first forward rotation driving pulse PF1a (specifically, the period from time t31A to time t32), step S31B in FIG. Since step S31C is executed and the induced voltage VRs has not become larger than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has not performed the predetermined normal rotation by the application of the first normal rotation driving pulse PF1a.

Next, at time t <b> 32, step S <b> 32 </ b> A of FIG. 8 is executed, and the motor drive circuit 109 applies the second normal rotation drive pulse PF <b> 1 b to the stepping motor 103.
Next, after the second determination period elapsed time t32A in which the determination period Tcomp elapses from the application time t32 of the second forward rotation driving pulse PF1b (specifically, the period from time t32A to time t33), step S32B in FIG. Since step S32C is executed and the induced voltage VRs has not become larger than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has not performed the predetermined normal rotation by the application of the second normal rotation driving pulse PF1b.

Next, at time t <b> 33, step S <b> 33 </ b> A in FIG. 8 is executed, and the motor drive circuit 109 applies the third normal rotation drive pulse PF <b> 1 c to the stepping motor 103.
Next, step S33B and step S33C of FIG. 8 are executed after the third determination period elapsed time t33A (specifically, time t33A) after the determination period Tcomp elapses from the application time t33 of the third normal rotation driving pulse PF1c. Since the induced voltage VRs is greater than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has performed a predetermined normal rotation by applying the third normal rotation driving pulse PF1c.

Next, at time t34, step S33D of FIG. 8 is executed, and the motor drive circuit 109 supplies the third forward rotation drive pulse PF1c to the stepping motor 103 as the drive pulse (repulsion pulse) P1 (see FIG. 3B). Apply.
Next, after time t35, step S40 in FIG. 8 is executed, and the reverse drive pulse whose pulse length is determined based on the pulse length of the third forward rotation drive pulse PF1c is generated by the motor drive circuit 109 as a drive pulse (suction). Pulse) P2 is applied to the stepping motor 103. As a result, the stepping motor 103 is reversed.
The difference between the example shown in FIG. 9 and the example shown in FIG. 10 is the presence or absence of the drive pulse P3. The present invention eliminates the need for the drive pulse P3 and enables reverse rotation only by the drive pulses P1 and P2. As a result, the pulse length required for the reverse rotation can be shortened, so that the reverse drive frequency can be further increased.

As described above, in the timepiece 1 of the second embodiment, the required time from the application time t21, t31 of the first forward rotation driving pulse PF1a to the time t21B, t31B when the induced voltage VRs greater than the reference threshold voltage Vcomp is generated. When it is shorter than the determination period Tcomp, it is determined that the stepping motor 103 is not performing the predetermined forward rotation.
Further, when the required time from the application time t22, t32 of the second forward rotation driving pulse PF1b to the time t22B, t32B when the induced voltage VRs greater than the reference threshold voltage Vcomp is generated is shorter than the determination period Tcomp, the stepping motor 103 It is determined that the predetermined forward rotation is not performed.
On the other hand, when the required time from the application time t23, t33 of the third forward rotation driving pulse PF1c to the time t23A, t33A when the induced voltage VRs larger than the reference threshold voltage Vcomp is generated is longer than the determination period Tcomp, the stepping motor 103 It is determined that a predetermined forward rotation has been performed.

(Modification)
Note that the pulse energy of the first forward drive pulse PF1a in the reverse rotation preparation process is energy determined by the control circuit 106 based on the pulse energy applied to the stepping motor 103 at the timing immediately before the start of the execution of the reverse rotation preparation process. There may be.
The timepiece 1 configured as described above can apply the pulse energy of the first forward rotation driving pulse PF1a to the stepping motor 103 with energy larger than a predetermined energy. Therefore, it is possible to shorten the period from the start of the reverse rotation preparation process until it is determined that the induced voltage VRs is greater than the reference threshold voltage Vcomp.

In the reverse rotation preparation process, the test pulses applied to the stepping motor 103 before determining the drive pulse P1 do not necessarily have the same polarity. Of the test pulses, the polarity of at least one test pulse may be different from the polarity of other test pulses. Specifically, until the drive pulse P1 is determined in the reverse rotation preparation process, a process in which a test pulse having the first polarity is applied and a test pulse having a second polarity different from the first polarity are included. An applied process may be executed. For example, when the first polarity is a positive polarity, the second polarity is a negative polarity. For example, when the first polarity is a negative polarity, the second polarity is a positive polarity.
The timepiece 1 configured as described above applies a test pulse having positive and negative polarities to the stepping motor 103 to determine the drive pulse P1. Therefore, the amount of excess or deficiency of energy required for rotation of the stepping motor 103 due to magnetic disturbance such as magnetic field influence or magnet polarization can be suppressed.

  Note that the time from the application of a test pulse to the application of the next test pulse is preferably 15 ms or more. If the time from when the test pulse is applied to when the next test pulse is applied is 15 ms or more, the rotation of the rotor 202 is stationary after the test pulse is applied until the next test pulse is applied. A decrease in the accuracy of energy determination by the test pulse is suppressed.

If the induced voltage VRs is not determined to be greater than the reference threshold voltage Vcomp even if the pulse energy of the test pulse is equal to or greater than a predetermined value, the motor drive circuit 109 sends the drive pulse P1 and the drive pulse P1 to the stepping motor 103. The pulse P2 and the drive pulse P3 whose energy is predetermined energy and whose polarity is the same as that of the first pulse may be applied. The predetermined pulse energy may be, for example, pulse energy that does not cause predetermined reverse rotation.
The timepiece 1 configured as described above can drive the pointer of the timepiece 1 in the reverse direction even when a detection failure of the induced voltage by the forward rotation drive rotation detection circuit 110 occurs.

  The rotor 202 is driven by the driving pulse P1 and the driving pulse P2 when the pulse length is determined to be within a predetermined range by the control circuit 106, and the pulse length is out of the predetermined range by the control circuit 106. May be driven by the drive pulse P1, the drive pulse P2, and the drive pulse P3.

  The first forward rotation driving pulse PF1a is an example of the first test pulse of the plurality of test pulses output continuously. The drive pulse P3 is an example of a third pulse.

  The program for realizing all or part of the functions of the timepiece 1 of the present invention is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. You may perform the process of. Here, the “computer system” includes an OS and hardware such as peripheral devices. Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.

  The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiments of the stepping motor control device, the timepiece, and the stepping motor control method of the present invention have been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the gist of the present invention. Design changes within a range that does not deviate from are included.

DESCRIPTION OF SYMBOLS 1 ... Clock, 101 ... Battery, 102 ... Stepping motor control apparatus, 103 ... Stepping motor, 104 ... Oscillation circuit, 105 ... Dividing circuit, 106 ... Control circuit, 107 ... Forward drive pulse generation circuit, 108 ... Reverse drive pulse Generation circuit 109 ... Motor drive circuit 110 ... Forward drive rotation detection circuit 111 ... Reverse drive control circuit 112 ... Watch case 113 ... Analog display unit 114 ... Movement 115 ... Hand pointer 116 ... Calendar display unit DESCRIPTION OF SYMBOLS 201 ... Stator, 202 ... Rotor, A ... Magnetic pole axis | shaft, 203 ... Through-hole for rotor accommodation, 204 ... Notch part (inner notch), 205 ... Notch part (inner notch), 206 ... Notch part (outer notch) 207: Notch (outer notch), 208: Magnetic core, 209 ... Drive coil, 210 ... Saturable part, 211 ... Saturable part, OU 1 ... first terminal, OUT2 ... second terminal, VRs ... induced voltage, Vs ... rotation detection signal, Vcomp ... reference threshold voltage

Claims (16)

A rotation detector for detecting a rotation state of the rotor of the stepping motor after outputting a driving pulse to the stepping motor for rotating the pointer;
A control unit that controls to drive the pointer in reverse by at least a first pulse and a second pulse having a polarity different from that of the first pulse as the driving pulse, and outputs energy to each other before outputting the first pulse. A plurality of first pulses having different values are output as a plurality of test pulses, and after each output of the plurality of test pulses, the rotation detection unit detects the rotation state of the rotor by the test pulse, and the detected rotation state is obtained. A control unit configured to set a corresponding test pulse as the first pulse, and to control the pointer to be driven in reverse using at least the set first pulse and the second pulse;
Stepping motor control device comprising: The plurality of test pulses are output in succession so that the pulses become higher in energy in order from the pulse having the lower energy,
The control unit according to claim 1, wherein the control unit sets a test pulse corresponding to the predetermined amount of energy that is a predetermined amount of energy less than that required for normal rotation of the pointer as the first pulse. Stepping motor control device. The controller determines that the rotor has the predetermined amount of energy and sets the test pulse as the first pulse when an induced voltage generated with the application of the test pulse is larger than a reference threshold voltage. ,
The stepping motor control device according to claim 2. The control unit determines that the rotor has the predetermined amount of energy when the required time from the application time of the test pulse to the time when an induced voltage greater than a reference threshold voltage is generated is longer than the determination period, and the test Setting a pulse as the first pulse;
The stepping motor control device according to claim 2 or claim 3. A stator capable of forming a magnetic path between the rotor and a drive coil capable of forming a magnetic path in the stator;
The stepping motor control device according to claim 1, wherein the control unit outputs the plurality of test pulses so that all of the plurality of test pulses are generated with a polarity of one side of the magnetic path.   A timepiece comprising the stepping motor control device according to claim 1 and the pointer. Outputting a plurality of first pulses having different energies as a plurality of test pulses before outputting the first pulse as a drive pulse to the stepping motor for rotating the pointer;
Detecting a rotation state of the rotor by the test pulse after each of the plurality of test pulses is output;
Setting a test pulse corresponding to the detected rotation state as the first pulse;
Driving the pointer in reverse using at least the set first pulse and the second pulse having a polarity different from that of the first pulse;
A stepping motor control method for a watch comprising: When starting reverse rotation of the stepping motor,
A first forward drive pulse having a pulse length that does not allow the stepping motor to perform a predetermined forward rotation is applied to the stepping motor, and the stepping motor performs a predetermined forward rotation by applying the first forward rotation drive pulse. To determine whether or not
When the stepping motor does not perform a predetermined normal rotation by applying the first normal rotation drive pulse, a second normal rotation drive pulse obtained by adding pulse energy to the first normal rotation drive pulse is obtained. Applying to the stepping motor and determining whether the stepping motor has performed a predetermined normal rotation by applying the second normal rotation driving pulse;
When the stepping motor performs a predetermined normal rotation by applying the second normal rotation driving pulse, the pulse length of the reverse driving pulse is determined based on the pulse length of the second normal rotation driving pulse,
Until the stepping motor performs a predetermined normal rotation, the addition of the pulse energy and the determination as to whether or not the stepping motor has performed a predetermined normal rotation by applying the normal rotation driving pulse after the addition are repeated.
Clock stepping motor control method. The application of the forward drive pulse is repeated until the stepping motor performs a predetermined forward rotation, and the reverse drive pulse is not applied until the stepping motor performs the predetermined forward rotation.
The timepiece stepping motor control method according to claim 8. When the induced voltage generated with the application of the first forward rotation driving pulse is larger than a reference threshold voltage, the predetermined forward rotation is determined.
The timepiece stepping motor control method according to claim 8 or 9. When the required time from the application time point of the first normal rotation driving pulse to the time point when the induced voltage greater than the reference threshold voltage is generated is equal to or longer than the determination period, the predetermined normal rotation is determined.
The timepiece stepping motor control method according to claim 8 or 9. The energy of the first test pulse of the plurality of test pulses output in succession was determined based on the energy of the drive pulse output to the stepping motor just before the output of the first test pulse. Energy,
The stepping motor control device according to any one of claims 1 to 4. Of the plurality of test pulses output in succession, the polarity of at least one test pulse is different from the polarity of the other test pulses.
The stepping motor control device according to any one of claims 1 to 4 or claim 12. In the control unit, the time from the application of the test pulse to the application of the next test pulse is 15 ms or more.
The stepping motor control device according to any one of claims 1 to 4 or claims 12 to 13. When the energy of the test pulse is greater than or equal to a predetermined value and the induced voltage generated with the application of the test pulse is not greater than a reference threshold voltage, the energy of the first pulse, the second pulse, Applying a third pulse having a predetermined energy and a polarity the same as the first pulse to the stepping motor;
The stepping motor control device according to any one of claims 1 to 4 or claim 12 to claim 14. When the pulse length of the first pulse set by the control unit is within a predetermined range, the first pulse is driven by the first pulse and the second pulse and is set by the control unit. If the pulse length of the first pulse is outside the predetermined range, the first pulse, the second pulse, and the first pulse having the same energy as the first pulse. Driven by 3 pulses,
The stepping motor control apparatus according to any one of claims 1 to 4 or claim 12 to claim 15.

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