JP7120901B2 - Stepping motor controller, clock and stepping motor control method for clock - Google Patents

Description

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

When a stepping motor used to drive the hands of a timepiece is driven by a single coil, it has the advantage of being able to reduce current consumption in forward rotation. It is necessary to connect or use two or more reversing pulses to rotate. In reverse rotation using such a reaction, the rotor is swung abruptly in the opposite direction, and therefore the stability of operation is likely to be affected by manufacturing variations and voltage. As a countermeasure, it is known to use a braking pulse after the reverse rotation. Since the total length of the pulse is lengthened, the frequency at the time of reverse rotation is limited, so the range of expression by the movement of the hands can be limited.

Japanese Patent Application Laid-Open No. 2002-200001 describes that in reverse drive, the length of the first pulse is changed according to the power supply voltage. By the way, the technique described in Patent Document 1 does not take measures against factors other than voltage.
Japanese Patent Application Laid-Open No. 2002-300000 describes that a reverse swing pulse for pulling 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-frequency high-speed driving may be restricted.
Patent Document 3 describes that the rank of the subsequent reverse rotation pulse is determined by detecting the rotation state of forward rotation. By the way, in the technique of the second embodiment of Patent Document 3, when determining the reverse rotation pulse, it is necessary to rotate the rotor forward by one step in order to detect the forward 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 instructions when starting the reverse rotation pulse.

JP-A-55-59375 Japanese Unexamined Patent Application Publication No. 2014-117028 JP 2014-196986 A

In view of the above-described problems, the present invention provides a stepping motor control apparatus, a timepiece, and a timepiece stepping motor control method that can ensure responsiveness when reverse rotation is desired using energy corresponding to the rotation state in reverse rotation control of a stepping motor. intended 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 the 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, wherein a plurality of first pulses having different energies are generated before outputting the first pulse. After outputting each of the plurality of test pulses, the rotation detection unit detects the rotation state of the rotor by the test pulses, and outputs the test pulse corresponding to the detected rotation state to the first rotor. and a control unit configured to drive the pointer in the reverse direction by using at least the first pulse and the second pulse which are set as pulses.

In the stepping motor control device according to the aspect of the present invention, the plurality of test pulses are continuously output so that the pulses with the smallest energy become the pulses with the largest energy, and the controller causes the needle to rotate forward. A test pulse may be set as the first pulse, which is a predetermined amount of energy less than the energy required for the rotor to respond to the predetermined amount of energy.

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

In the stepping motor control device according to the aspect of the present invention, when the time required from the application of the test pulse to the generation of an induced voltage greater than a reference threshold voltage is equal to or longer than the determination period, the The rotor may be determined to have the predetermined amount of energy, and the test pulse may be set 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 with the stator, wherein the control unit comprises the The plurality of test pulses may be output such that all of the plurality of test pulses are generated by one polarity of the magnetic path.

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

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

A timepiece stepping motor control method according to an aspect of the present invention applies a first forward rotation drive pulse having a pulse length to the extent that the stepping motor does not rotate in a predetermined forward direction to the stepping motor when the stepping motor starts reverse rotation. At the same time, it is determined whether or not the stepping motor has rotated in the predetermined forward direction by applying the first forward rotation drive pulse, and the stepping motor has rotated in the predetermined forward direction by the application of the first forward rotation drive pulse. If not, a second forward driving pulse obtained by adding pulse energy to the first forward driving pulse is applied to the stepping motor, and the stepping is performed by applying the second forward driving pulse. It is determined whether or not the motor has rotated in the predetermined forward direction, and if the stepping motor has rotated in the predetermined direction due to the application of the second forward rotation drive pulse, the pulse length of the second forward rotation drive pulse is determined. The pulse length of the reverse drive pulse is determined based on the above, and the stepping motor rotates in the predetermined forward direction by adding the pulse energy and applying the forward rotation drive pulse after the addition until the stepping motor rotates in the predetermined forward direction. Repeat the determination of whether or not

In a timepiece stepping motor control method according to an aspect of the present invention, application of a forward rotation drive pulse is repeated until the stepping motor rotates in a predetermined forward direction, and during the period until the stepping motor rotates in a predetermined forward direction, Application of the reverse driving pulse may not be performed.

In the timepiece stepping motor control method according to the aspect of the present invention, when the induced voltage generated with the application of the first forward rotation driving pulse is higher than the reference threshold voltage, the predetermined forward rotation is determined. good too.

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

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 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 the aspect of the present invention, the polarity of at least one of the plurality of test pulses that are continuously output is different from the polarities of the other test pulses.

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

In the stepping motor control device according to the 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 by application of the test pulse is not greater than the reference threshold voltage, the A first pulse, the second pulse, and a third pulse having predetermined energy and the same polarity as the first pulse are applied to the stepping motor.

In the stepping motor control device according to the 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 When the pulse length of the first pulse which is driven and set by the control unit is out of the predetermined range, the energy of the first pulse and the second pulse is predetermined energy. and 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 stepping motor control method for a timepiece that can ensure responsiveness when reverse rotation of a stepping motor is desired using energy corresponding to the state of rotation in reverse rotation control of the stepping motor. can.

1 is a diagram showing an example of a schematic configuration of a timepiece according to a first embodiment; FIG. 2 is a diagram showing an example of a configuration of a stepping motor shown in FIG. 1; FIG. FIG. 4 is a diagram for explaining a general technique for driving a stepping motor in reverse; It is a figure for demonstrating the problem of the example shown to FIG. 3(A). 4 is a flowchart for explaining an example of processing (reverse rotation preparation processing) such as optimization of the length of drive pulse P1 executed by the timepiece of the first embodiment; 6 is a time chart for explaining an example in which the process shown in FIG. 5 is executed by the clock of the first embodiment; FIG. 6 is a time chart for explaining another example in which the process shown in FIG. 5 is executed by the clock of the first embodiment; FIG. 9 is a flowchart for explaining an example of processing (reverse rotation preparation processing) such as optimization of the length of drive pulse P1 executed by the timepiece of the second embodiment; FIG. 9 is a time chart for explaining an example of execution of the process shown in FIG. 8 by the clock of the second embodiment; FIG. 9 is a time chart for explaining another example in which the process shown in FIG. 8 is executed by the clock of the second embodiment; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION 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 showing 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 controller 102, a stepping motor 103, a watch case 112, an analog display section 113, a movement 114, hands 115, and a calendar display section 116. and
A battery 101 supplies power to a stepping motor controller 102 and the like. The stepping motor controller 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 forward rotation drive pulse generation circuit 107, a reverse rotation drive pulse generation circuit 108, a motor drive circuit 109, and a forward rotation drive rotation circuit. A detection circuit 110 and a reverse drive control circuit 111 are provided.
Oscillating circuit 104 generates a signal of a predetermined frequency. A frequency dividing circuit 105 divides the frequency of the signal generated by the oscillation circuit 104 to generate a clock signal that serves as a timekeeping reference. Based on the clock signal generated by the frequency dividing circuit 105, the control circuit 106 controls each electronic circuit element forming the electronic timepiece and controls the change of the drive pulse.

A forward rotation drive pulse generation circuit 107 generates a forward rotation drive pulse for driving the stepping motor 103 in the forward rotation based on the control signal generated by the control circuit 106 . Specifically, the forward rotation drive pulse generation circuit 107 can generate a main drive pulse and an auxiliary drive pulse having a higher driving force than the main drive pulse based on the control signal generated by the control circuit 106 .
A reverse drive pulse generating 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 a forward drive pulse generated by the forward drive pulse generation circuit 107 or a reverse drive pulse generated by the reverse drive pulse generation circuit 108 .
The forward rotation detection circuit 110 detects the induced voltage VRs generated by the free vibration of the rotor 202 (see FIG. 2) of the stepping motor 103 after the stepping motor 103 applies the magnetic force of the drive pulse to the rotor 202. to detect the rotation status of the stepping motor 103 . Specifically, the forward rotation drive rotation detection circuit 110 performs stepping in accordance with when the induced voltage VRs is greater than the reference threshold voltage Vcomp, when the induced voltage VRs is less than or equal to the reference threshold voltage Vcomp, and when these cases occur. The rotation state of the motor 103 can be determined. Further, the forward drive rotation detection circuit 110 outputs a rotation detection signal Vs to the control circuit 106 when the induced voltage VRs is greater than the reference threshold voltage Vcomp.
The reverse drive control circuit 111 outputs to the control circuit 106 a reverse drive control signal representing the margin of 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 housing 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 .
Stator 201 is made of a magnetic material. The stator 201 is formed with a rotor housing through hole 203 for housing the rotor 202 . The rotor housing through-hole 203 has notches (inner notches) 204 and 205 .
Further, notches 206 and 207 are formed in the stator 201 . A saturable portion 210 is provided between the rotor-accommodating through-hole 203 and the notch portion 206 . A saturable portion 211 is provided between the rotor-accommodating through-hole 203 and the notch portion 207 .
The rotor 202 is magnetized with two poles (specifically, S pole and N pole). Further, the rotor 202 is arranged in the rotor housing through-hole 203 so as to be rotatable with respect to the stator 201 . The notch portions 204 and 205 constitute positioning portions for determining the stop position of the rotor 202 with respect to the stator 201 .
Magnetic core 208 is joined to stator 201 . Magnetic core 208 and stator 201 are fixed to a ground plate (not shown). Drive coil 209 is wound around 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. As shown in FIG.
The saturable portions 210 and 211 are not magnetically saturated by the magnetic flux of the rotor 202, but are magnetically saturated when the drive coil 209 is excited and the magnetic resistance increases. That is, a magnetic path can be formed between stator 201 and rotor 202 . Also, a magnetic path can be formed in the stator 201 by the drive coil 209 .

For example, when the drive coil 209 is not energized, as shown in FIG. 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 is generated as shown by the dashed arrow. As a result, the saturable portions 210 and 211 are saturated and the magnetic resistance increases. After that, the interaction between the magnetic poles generated in the stator 201 and the magnetic poles of the rotor 202 causes the rotor 202 to rotate 180 degrees counterclockwise in FIG. Rotate and stop stably. This rotation of approximately 180 degrees allows the hands 115 of the timepiece 1 to move by a prescribed amount of one graduation. The prescribed amount of operation may be referred to as one step. A gear train having an appropriate speed reduction ratio is appropriately arranged between the rotor 202 and the pointer 115 so that the specified amount of movement is achieved.
With the rotor 202 rotated approximately 180 degrees from the state shown in FIG. , a magnetic flux is generated in the stator 201 in the direction opposite to the dashed arrow. As a result, the saturable portions 210 and 211 are first saturated, and then the interaction between the magnetic poles of the stator 201 and the rotor 202 causes the rotor 202 to rotate 180 degrees counterclockwise in FIG. to stop.
By supplying signals of different polarities (alternating signals) to the drive coil 209 in this manner, the rotor 202 is continuously rotated counterclockwise in FIG. 2 by approximately 180 degrees.

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

FIG. 3 is a diagram for explaining a general technique for driving the stepping motor 103 in reverse. 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 method of reversing the stepping motor 103 by applying two drive pulses.
In the example shown in FIG. 3A, first, a drive pulse (repulsion pulse) P1 for rotating the rotor 202 of the stepping motor 103 in the normal direction is applied to the stepping motor 103. In the example shown in FIG. Next, a drive pulse (attraction pulse) P2 for rotating the rotor 202 of the stepping motor 103 is applied to the stepping motor 103 . A drive pulse P3 is then 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 direction by the drive pulse P1. Then, using the recoil of the rotation in the forward direction, it is reversed by the drive pulse P2 and the drive pulse P3.

In the example shown in FIG. 3B, first, a drive pulse (repulsion pulse) P1 for forwardly rotating the rotor 202 of the stepping motor 103 is applied to the stepping motor 103 . Next, a drive pulse (attraction pulse) P2 for rotating 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 direction by the drive pulse P1. Then, it is reversed by the driving pulse P2 using the reaction of the rotation in the forward direction.
As shown in FIG. 3B, the reverse rotation of the rotor 202 of the stepping motor 103 is established only by the two driving pulses of the repulsion pulse P1 and the attraction pulse P2. On the other hand, as a countermeasure against step-out due to manufacturing variations and magnetic fields, it is common to add a driving pulse P3 as shown in FIG. 3(A). The drive pulse P3 acts as repulsion→attraction.
Such a set of drive pulses P1, P2, P3 is hereinafter referred to as a reverse pulse or a reverse drive pulse. Further, the reverse rotation pulse or the reverse rotation driving pulse can be configured only by the drive pulses P1 and P2.

FIG. 4 is a diagram for explaining the problem of the example shown in FIG. 3(A).
In FIG. 4 , the vertical axis indicates the current consumption of the stepping motor 103 . The horizontal axis indicates time. "IP1" indicates the instantaneous value of current consumption of the stepping motor 103 associated with the application of the driving pulse P1. "IP2" indicates the instantaneous value of current consumption of the stepping motor 103 associated with the application of the drive pulse P2. "IP3" indicates the instantaneous value of current consumption of the stepping motor 103 associated with the application of the drive pulse P3.
In the example shown in FIG. 4, the current consumption (integral value) of the stepping motor 103 due to the application of the drive pulse P1 and the drive pulse P2 accounts for 18% of the total current consumption. The current consumption (integral value) of the stepping motor 103 accompanying the application of the driving pulse P3 accounts for 82% of the total current consumption.
The time required to rotate 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 entire time required to rotate. The time required to rotate the rotor 202 of the stepping motor 103 accompanying the application of the drive pulse P3 occupies 81% of the entire time required to rotate.
As shown in FIG. 4, when the drive pulse P3 is applied, the time required for the entire rotation of the rotor 202 of the stepping motor 103 becomes longer. In other words, 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 increases. In other words, it may be difficult to reduce the power consumption of the reverse rotation of the rotor 202 of the stepping motor 103 .

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

FIG. 5 is a flow chart for explaining an example of processing such as optimization of the length of the drive pulse P1 (reverse rotation preparation processing) 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 rotating in reverse), the motor drive circuit 109 first causes the stepping motor 103 to rotate at a predetermined speed in step S11A. The stepping motor 103 is applied with a first forward rotation drive pulse PF1a having a pulse length that does not cause forward rotation (forward rotation of less than 180 degrees).
Here, the relationship between predetermined forward rotation and normal rotation will be described. Predetermined forward rotation refers to a rotational state in which the orientation of the magnetic poles of the rotor (arrow A in FIG. 2) does not just exceed the position of the notch 205 (notch 204 in the case of a drive pulse of opposite polarity). Once the magnetic poles of the rotor exceed the notch 205, the maximum magnetic potential energy has been exceeded, and the rotor can continue to rotate up to approximately 180 degrees. Such rotation beyond the maximum potential energy point is called normal rotation. As a result, the rotor can be rotated approximately 180 degrees, and the hands can be moved one step. If the magnetic pole of the rotor cannot exceed the notch 205, it cannot exceed the maximum potential energy point and tries to return to the 0 degree position, which is the starting position before the drive pulse is applied.
Next, in step S11B, the forward rotation detection circuit 110 detects the induced voltage VRs.
Next, in step S11C, the forward 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 rotated in the predetermined forward direction by applying the first forward rotation drive 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 such a pulse length that the stepping motor 103 does not rotate in the predetermined forward direction. Therefore, in step S11C, the forward drive rotation detection circuit 110 does not determine that the induced voltage VRs is greater than the reference threshold voltage Vcomp.
If the induced voltage VRs is equal to or lower than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 did not rotate in the predetermined forward direction due to the application of the first forward rotation drive pulse PF1a, and the process proceeds to step S12A.
In step S11D, the motor drive circuit 109 applies the first forward rotation drive pulse PF1a to the stepping motor 103 as the drive pulse (repulsion pulse) P1 described above. Then, the process proceeds to step S20.

In step S12A, the motor drive circuit 109 applies to the stepping motor 103 a second forward drive pulse PF1b obtained by adding pulse energy to the first forward drive pulse PF1a. This control is sometimes called rank up.
Next, in step S12B, the forward rotation detection circuit 110 detects the induced voltage VRs.
Next, in step S12C, the forward 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 higher than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has rotated in the predetermined forward direction by applying the second forward rotation drive pulse PF1b, and the process proceeds to step S12D.
If the induced voltage VRs is equal to or lower than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 did not rotate in the predetermined forward direction due to the application of the second forward rotation drive pulse PF1b, and the process proceeds to step S13A.
In step S12D, the motor drive circuit 109 applies the second forward rotation drive pulse PF1b to the stepping motor 103 as the drive pulse (repulsion pulse) P1 described above. Then, the process proceeds to step S20.

In step S13A, the motor drive circuit 109 applies to the stepping motor 103 a third forward drive pulse PF1c obtained by adding pulse energy to the second forward drive pulse PF1b (rank up).
Next, in step S13B, the forward rotation detection circuit 110 detects the induced voltage VRs.
Next, in step S13C, the forward 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 higher than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has rotated in the predetermined forward direction by applying the third forward rotation drive pulse PF1c, and the process proceeds to step S13D.
If the induced voltage VRs is equal to or lower than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 did not rotate in the predetermined forward direction due to the application of the third forward rotation drive pulse PF1c, and the process proceeds to step S14.
In step S13D, the motor drive circuit 109 applies the third forward rotation drive pulse PF1c to the stepping motor 103 as the drive pulse (repulsion pulse) P1 described above. Then, the process proceeds to step S20.

In step S14, it is determined whether or not the stepping motor 103 rotates in a predetermined forward direction by adding the pulse energy and applying the forward rotation driving pulse after adding the pulse energy until the induced voltage VRs becomes larger than the reference threshold voltage Vcomp. is repeated, and the forward rotation driving pulse when the induced voltage VRs exceeds the reference threshold voltage Vcomp is applied to the stepping motor 103 as the driving pulse (repulsion pulse) P1 described above.

In step S20, the pulse length of the reverse driving pulse is determined based on the pulse length of the driving pulse when the induced voltage VRs exceeds 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 forward drive pulse PF1c. The pulse length determined here is a predetermined amount of energy less than the energy required to rotate the hands forward.
Further, in step S20, the motor drive circuit 109 applies the reverse drive pulse as the drive pulse (attraction pulse) P2 to the stepping motor 103 described above. As a result, as shown in FIG. 3B, the rotor 202 of the stepping motor 103 is reversed.

Specifically, in the example shown 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 rotates forward by a predetermined amount due to the pulse energy in step S13A. It is determined that it has rotated, and it is driven in the forward rotation direction in step S13D with an energy equivalent to the pulse energy. The predetermined amount refers to a state in which the direction of the magnetic poles of the rotor (arrow A in FIG. 2) does not exceed the position of the notch 205 (notch 204 in the case of a drive pulse of opposite polarity). The predetermined amount is the amount of rotation when the rotor is rotated by the energy corresponding to the above-described predetermined forward rotation or the driving 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.

According to the example shown in FIG. 5, the stepping motor 103 can be reversed by using a forward rotation drive pulse having a predetermined pulse length for forward rotation of the stepping motor 103 . As a result, it is possible to increase the speed of reverse rotation of the stepping motor 103 and reduce power consumption.

FIG. 6 is a time chart for explaining an example of execution of the processing shown in FIG. 5 by the timepiece 1 of the first embodiment.
6, step S11A in FIG. 5 is executed at time t1, and the motor drive circuit 109 applies the first forward rotation drive pulse PF1a to the stepping motor 103.
Next, steps S11B and S11C of FIG. 5 are executed before time t2, 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 forward direction by the application of the first forward rotation drive pulse PF1a. was determined not to have

Next, at time t2, step S12A in FIG. 5 is executed, and the motor drive circuit 109 applies the second forward rotation drive pulse PF1b 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 forward direction by the application of the second forward rotation drive pulse PF1b. was determined not to have

Next, at time t3, step S13A in FIG. 5 is executed, and the motor drive circuit 109 applies the third forward rotation drive pulse PF1c to the stepping motor 103.
Next, at time t3A, steps S13B and S13C of FIG. 5 are executed, the induced voltage VRs is greater than the reference threshold voltage Vcomp, and the stepping motor 103 rotates in a predetermined forward direction due to the application of the third forward rotation drive pulse PF1c. is determined.

Next, at time t4, step S13D in FIG. 5 is executed, and the motor drive circuit 109 sends a third forward rotation drive pulse PF1c to the stepping motor 103 as a drive pulse (repulsion pulse) P1 (see FIG. 3B). apply.
Next, after time t5, 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 drive pulse PF1c is generated by the motor drive circuit 109 as a drive pulse (attraction pulse). are applied to the stepping motor 103 as pulses P2 and P3. 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, at time t11, step S11A in FIG.
Next, steps S11B and S11C of FIG. 5 are executed before time t12, 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 forward direction by the application of the first forward rotation drive pulse PF1a. was determined not to have

Next, at time t12, step S12A in FIG. 5 is executed, and the motor drive circuit 109 applies the second forward rotation drive pulse PF1b to the stepping motor 103.
Next, before time t13, 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 forward direction by the application of the second forward rotation drive pulse PF1b. was determined not to have

Next, at time t13, step S13A in FIG. 5 is executed, and the motor drive circuit 109 applies the third forward rotation drive pulse PF1c to the stepping motor 103.
Next, at time t13A, steps S13B and S13C of FIG. 5 are executed, the induced voltage VRs is greater than the reference threshold voltage Vcomp, and the stepping motor 103 rotates in a predetermined forward direction due to the application of the third forward rotation drive pulse PF1c. is determined.

Next, at time t14, step S13D in FIG. 5 is executed, and the motor drive circuit 109 sends a third forward rotation drive pulse PF1c to the stepping motor 103 as a 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 drive pulse PF1c is generated by the motor drive circuit 109 as a drive pulse (attraction pulse). is applied to the stepping motor 103 as a pulse) P2. 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 does not require the drive pulse P3, and enables reverse rotation by only the drive pulses P1 and P2. As a result, the pulse length required for reverse rotation can be shortened, so that the driving frequency for reverse rotation can be further increased.

[Summary of the first embodiment]
As described above, in the timepiece 1 of the first embodiment, drive pulses PF1a, PF1b, PF1c, etc. are output to the stepping motor 103 that rotates the hands 115 in steps S11A, S12A, S13A, etc. of FIG. After outputting the driving pulses PF1a, PF1b, PF1c, etc., the rotational state of the rotor 202 of the stepping motor 103 is detected in steps S11B, S12B, S13B, etc. FIG.
For example, in the example shown in FIGS. 5 and 6, steps S11A and S12A are performed before the third forward rotation drive pulse PF1c is output as the drive pulse (repulsion pulse) P1 (see FIG. 3B) in step S13D. And in step S13A, a plurality of forward drive pulses PF1a, PF1b, and PF1c having different energies are output as a plurality of test pulses.
After outputting the test pulse PF1a, in step S11B, the rotational state of the rotor 202 due to the test pulse PF1a is detected. After outputting the test pulse PF1b, the rotational state of the rotor 202 is detected by the test pulse PF1b in step S12B. After outputting the test pulse PF1c, the rotational state of the rotor 202 is detected by the test pulse PF1c in step S13B.
When the rotation of the rotor 202 by the test pulse PF1c is detected in steps S13B and S13C, the test pulse PF1c that causes the rotor 202 to rotate in a predetermined forward direction is set as the forward rotation drive pulse PF1c in step S13D. The transfer drive pulse PF1c is output as the drive pulse (repulsion pulse) P1.
Further, in step S20, reverse drive pulses having polarities different from the forward drive pulse PF1c are output as drive pulses (attraction pulses) P2 (see FIGS. 6 and 7) and P3 (see FIG. 6).
That is, in the examples shown in FIGS. 5, 6, and 7, the hands 115 are reversely driven by the forward driving pulse PF1c output in step S13D and the reverse driving 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 responsiveness when reverse rotation is desired using energy according to the rotation state. Specifically, the optimum energy of the drive pulse required for reverse rotation can be selected without rotating the rotor 202 . Therefore, it is possible to ensure responsiveness at the start of reverse rotation.

For example, in the examples shown in FIGS. 5, 6, and 7, a plurality of test pulses PF1a, PF1b, and PF1c are successively output from the pulse PF1a with the lowest energy to the pulse PF1c with the highest energy. Further, a test pulse PF1c corresponding to the energy of the rotation pulse immediately before the rotor 202 reaches the rotation angle corresponding to the specified amount, which is less than the energy required to rotate the hands 115 forward, is used for forward rotation driving. It is set as pulse PF1c and output in step S13D.
Specifically, when the induced voltage VRs generated with the application of the test pulse PF1c is greater 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 forward drive pulse PF1c.
Therefore, according to the timepiece 1 of the first embodiment, the possibility that a pulse having energy greater than that of the test pulse PF1c (that is, energy greater than necessary) is set as the forward rotation drive pulse and output is suppressed. be able to.
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). , output a plurality of test pulses PF1a, PF1b, PF1c.

For example, in the example shown in FIG. 6, test pulses such as forward drive pulses PF1a, PF1b, and PF1c are generated before time t3A when it is detected that the stepping motor 103 has the minimum energy for forming a reverse drive pulse. The application is repeated. Specifically, the forward drive pulse PF1a is applied at time t1, the forward drive pulse PF1b is applied at time t2, and the forward drive pulse PF1c is applied at time t3. Note that this is just an example, and the number of these test pulses is continued until an induced voltage such as time t3A is detected.
No reverse drive pulse is applied before time t3A at which the stepping motor 103 rotates in the predetermined forward direction. The reverse drive pulse is applied 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 uselessly before the time t3 when the forward rotation reaction is insufficient.

<Second embodiment>
A second embodiment of the stepping motor control device, clock, and stepping motor control method of the present invention will be described below 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 later. Therefore, according to the timepiece 1 of the second embodiment, it is possible to achieve the same effects as the timepiece 1 of the first embodiment described above, except for the points described later.

FIG. 8 is a flow chart for explaining an example of processing such as optimization of the length of the drive pulse P1 (reverse rotation preparation processing) 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 rotating in reverse), first in step S31A, the motor drive circuit 109 causes the stepping motor 103 to A first forward rotation driving pulse PF1a having a pulse length that does not cause forward rotation is applied to the stepping motor 103 .
Next, in step S31B, the forward drive rotation detection circuit 110 detects the induced voltage VRs after the first determination period Tcomp elapses from the application of the first forward drive pulse PF1a. .
Next, in step S31C, the forward drive rotation detection circuit 110 determines whether or not the induced voltage VRs has become greater than the reference threshold voltage Vcomp after the first determination period has elapsed.
If the induced voltage VRs becomes greater than the reference threshold voltage Vcomp after the first determination period has elapsed, it is determined that the stepping motor 103 has rotated in the predetermined forward direction by applying the first forward rotation drive pulse PF1a. Proceed to S31D. As described above, the pulse length of the first forward rotation driving pulse PF1a is set to such a pulse length that the stepping motor 103 does not rotate in the predetermined forward direction. Therefore, in step S31C, the forward drive rotation detection circuit 110 does not determine that the induced voltage VRs has become greater than the reference threshold voltage Vcomp after the first determination period has elapsed.
If the induced voltage VRs does not exceed the reference threshold voltage Vcomp after the first determination period has elapsed, it is determined that the stepping motor 103 did not rotate in the predetermined forward direction due to the application of the first forward rotation drive pulse PF1a. , the process proceeds to step S32A.
In step S31D, the motor drive circuit 109 applies the first forward rotation drive pulse PF1a to the stepping motor 103 as the drive pulse (repulsion pulse) P1 described above. Then, the process proceeds to step S40.

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

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

In step S34, the pulse energy is added and the forward rotation after the addition of the pulse energy is performed until the induced voltage VRs becomes larger than the reference threshold voltage Vcomp after the determination period Tcomp has elapsed from the application of the forward rotation drive pulse. Determination as to whether or not the stepping motor 103 has rotated in a predetermined forward direction by application of the drive pulse is repeated. (Rebound pulse) P1 is applied to the stepping motor 103 .

In step S40, the pulse length of the reverse driving pulse is determined based on the pulse length of the driving pulse when the induced voltage VRs exceeds 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. be.
For example, if 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.
Also, in step S40, the motor drive circuit 109 applies the reverse drive pulse as the drive pulse (attraction pulse) P2 to the stepping motor 103 described above. As a result, as shown in FIG. 3B, the rotor 202 of the stepping motor 103 is reversed.

Specifically, in the example shown in FIG. 8, for example, when it is determined in step S33C that the induced voltage VRs is greater than the reference threshold voltage Vcomp, the stepping motor 103 rotates in the predetermined forward direction with the pulse energy in step S33A. is determined, and the drive is performed in the normal direction at step S33D with an energy equivalent to the pulse energy. Note that the predetermined forward rotation means that the direction of the magnetic poles of the rotor (arrow A in FIG. 2) is aligned with the position of the notch 205 (the notch 204 in the case of a drive pulse of opposite polarity), as in the first embodiment. 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 it has exceeded the position of maximum potential energy in terms of magnetic field, and the rotor can rotate in the normal direction up to approximately 180 degrees.
Using the energy of the pulse as the drive pulse P1, at least the drive pulse P2 is set in step S40.

In the example shown in FIG. 8, the rotor 202 corresponds to a predetermined forward rotation when the time required from the application of the test pulse to the generation of the induced voltage VRs greater than the reference threshold voltage Vcomp is equal to or longer than the determination period Tcomp. It is judged as energy, and the test pulse is set as the drive pulse P1.
According to the example shown in FIG. 8, like the example shown in FIG. 5, the stepping motor 103 can be rotated by a forward rotation drive pulse having a pulse length that causes the stepping motor 103 to rotate in a predetermined forward direction. As a result, it is possible to increase the speed of reverse rotation of the stepping motor 103 and reduce power consumption.

FIG. 9 is a time chart for explaining an example of execution of the processing shown in FIG. 8 by the timepiece 1 of the second embodiment.
In the example shown in FIG. 9, step S31A in FIG. 8 is executed at time t21, and the motor drive circuit 109 applies the first forward rotation drive pulse PF1a to the stepping motor 103.
After the first determination period elapsed time t21A when the determination period Tcomp elapses from the application time t21 of the first forward rotation drive pulse PF1a (more specifically, the period from time t21A to time t22), steps S31B and Since step S31C is executed and the induced voltage VRs does not exceed the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has not rotated in the predetermined forward direction due to the application of the first forward rotation drive pulse PF1a.

Next, at time t22, step S32A in FIG. 8 is executed, and the motor drive circuit 109 applies the second forward rotation drive pulse PF1b to the stepping motor 103.
After the second determination period elapsed time t22A when the determination period Tcomp elapses from the application time t22 of the second forward rotation drive pulse PF1b (more specifically, the period from time t22A to time t23), steps S32B and Since step S32C is executed and the induced voltage VRs does not exceed the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has not rotated in the predetermined forward direction due to the application of the second forward rotation drive pulse PF1b.

Next, at time t23, step S33A in FIG. 8 is executed, and the motor drive circuit 109 applies the third forward rotation drive pulse PF1c to the stepping motor 103. FIG.
After the third determination period elapsed time t23A (more specifically, time t23A) when the determination period Tcomp elapses from the application time t23 of the third forward rotation drive pulse PF1c, steps S33B and S33C of FIG. 8 are executed, Since the induced voltage VRs has become higher than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has rotated in the predetermined forward direction due to the application of the third forward rotation drive pulse PF1c.

Next, at time t24, step S33D in FIG. 8 is executed, and the motor drive circuit 109 sends 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 (attraction pulse). It is applied to the stepping motor 103 as pulses P2 and P3. 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 S31A in FIG. 8 is executed at time t31, and the motor drive circuit 109 applies the first forward rotation drive pulse PF1a to the stepping motor 103.
After the first determination period elapsed time t31A when the determination period Tcomp elapses from the application time t31 of the first forward rotation drive pulse PF1a (more specifically, the period from time t31A to time t32), steps S31B and Since step S31C is executed and the induced voltage VRs does not exceed the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has not rotated in the predetermined forward direction due to the application of the first forward rotation drive pulse PF1a.

Next, at time t32, step S32A in FIG. 8 is executed, and the motor drive circuit 109 applies the second forward rotation drive pulse PF1b to the stepping motor 103.
After the second determination period elapsed time t32A when the determination period Tcomp elapses from the application time t32 of the second forward rotation drive pulse PF1b (more specifically, the period from time t32A to time t33), steps S32B and Since step S32C is executed and the induced voltage VRs does not exceed the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has not rotated in the predetermined forward direction due to the application of the second forward rotation drive pulse PF1b.

Next, at time t33, step S33A in FIG. 8 is executed, and the motor drive circuit 109 applies the third forward rotation drive pulse PF1c to the stepping motor 103.
Next, after the third determination period elapsed time t33A (more specifically, time t33A) when the determination period Tcomp elapses from the application time t33 of the third forward rotation drive pulse PF1c, steps S33B and S33C of FIG. 8 are executed, Since the induced voltage VRs has become higher than the reference threshold voltage Vcomp, it is determined that the stepping motor 103 has rotated in the predetermined forward direction due to the application of the third forward rotation drive pulse PF1c.

Next, at time t34, step S33D in FIG. 8 is executed, and the motor drive circuit 109 sends a third forward rotation drive pulse PF1c to the stepping motor 103 as a 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 drive pulse PF1c is generated by the motor drive circuit 109 as a drive pulse (attraction pulse). is applied to the stepping motor 103 as a pulse) P2. 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 does not require the drive pulse P3, and enables reverse rotation by only the drive pulses P1 and P2. As a result, the pulse length required for reverse rotation can be shortened, so that the driving frequency for reverse rotation can be further increased.

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

(Modification)
The pulse energy of the first forward rotation drive pulse PF1a in the reverse rotation preparation process is determined by the control circuit 106 based on the pulse energy applied to the stepping motor 103 immediately before the execution of the reverse rotation preparation process is started. There may be.
The timepiece 1 configured in this manner can apply the pulse energy of the first forward rotation drive pulse PF1a to the stepping motor 103 with energy greater 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 higher than the reference threshold voltage Vcomp.

In the reverse rotation preparation process, the test pulses applied to the stepping motor 103 until the driving pulse P1 is determined do not necessarily have the same polarity. The polarity of at least one of the test pulses may differ from the polarities of the other test pulses. Specifically, until the drive pulse P1 is determined in the reverse rotation preparation process, a process of applying a test pulse of a first polarity and a test pulse of a second polarity that is different from the first polarity are performed. applied treatment may be performed. If the first polarity is, for example, positive polarity, the second polarity is negative polarity. If the first polarity is, for example, negative polarity, the second polarity is positive polarity.
The timepiece 1 configured in this manner applies test pulses of positive and negative polarities to the stepping motor 103 to determine the drive pulse P1. Therefore, it is possible to suppress excess or deficiency of energy required for rotation of the stepping motor 103 due to magnetic disturbance such as the influence of the magnetic field and the polarization of the magnet.

It is desirable that the time from the application of the test pulse to the application of the next test pulse is 15 ms or longer. If the time from the application of the test pulse to the application of the next test pulse is 15 ms or more, the rotation of the rotor 202 will stop after the application of the test pulse until the application of the next test pulse. , the deterioration of the accuracy of the energy determination due to the test pulse is suppressed.

If it is not determined that the induced voltage VRs is higher than the reference threshold voltage Vcomp even if the pulse energy of the test pulse is equal to or greater than the predetermined value, the motor drive circuit 109 supplies the stepping motor 103 with a drive pulse P1 and a drive pulse P1. A pulse P2 and a drive pulse P3 having a predetermined energy and the same polarity as the first pulse may be applied. The predetermined pulse energy may be, for example, a pulse energy that does not cause a predetermined reversal.
In the timepiece 1 configured in this way, even when the normal rotation detection circuit 110 fails to detect the induced voltage, the hands of the timepiece 1 can be driven in the reverse direction.

The rotor 202 is driven by the drive pulse P1 and the drive pulse P2 when the control circuit 106 determines that the pulse length is within the predetermined range. , it may be driven by drive pulse P1, drive pulse P2 and drive pulse P3.

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

A program for implementing all or part of the functions of the timepiece 1 of the present invention is recorded in a computer-readable recording medium, and the program recorded in the recording medium is read by a computer system and executed. may be processed. It should be noted that the "computer system" referred to here includes hardware such as an OS and peripheral devices. The "computer system" also includes the home page providing environment (or display environment) if the WWW system is used.

The term "computer-readable recording medium" refers to portable media such as flexible discs, magneto-optical discs, ROMs and CD-ROMs, and storage devices such as hard discs incorporated in computer systems. Furthermore, "computer-readable recording medium" means a medium that dynamically retains a program for a short period of 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. It also includes those that hold programs for a certain period of time, such as volatile memories inside computer systems that serve as servers and clients in that case. Further, the program may be for realizing part of the functions described above, or may be capable of realizing the functions described above in combination with a program already recorded in the computer system.

Although the embodiments of the stepping motor control device, timepiece, and stepping motor control method of the present invention have been described in detail with reference to the drawings, the specific configurations are not limited to these embodiments, and the gist of the present invention. It also includes design changes, etc. within a range that does not deviate from

Reference Signs List 1 clock 101 battery 102 stepping motor controller 103 stepping motor 104 oscillation circuit 105 frequency dividing circuit 106 control circuit 107 forward drive pulse generation circuit 108 reverse drive pulse Generating circuit 109 Motor drive circuit 110 Forward drive rotation detection circuit 111 Reverse drive control circuit 112 Watch case 113 Analog display section 114 Movement 115 Hand 116 Calendar display section 201... Stator 202... Rotor A... Magnetic pole shaft 203... Through hole for rotor accommodation 204... Notch (inner notch) 205... Notch (inner notch) 206... Notch (outer notch) , 207... notch (outer notch), 208... magnetic core, 209... drive coil, 210... saturable part, 211... saturable part, OUT1... first terminal, OUT2... second terminal, VRs... induced voltage, Vs ... rotation detection signal, Vcomp ... reference threshold voltage

Claims (16)

a rotation detection unit that detects the rotation state of the rotor of the stepping motor after outputting the drive pulse to the stepping motor that rotates the pointer;
A control unit for controlling the pointer to be reversely driven by at least a first pulse and a second pulse having a polarity different from that of the first pulse as the driving pulse, wherein energy is generated from each other before outputting the first pulse. 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 pulses, and the detected rotation state is a control unit that sets a corresponding test pulse as the first pulse, and controls the pointer to be reversely driven by using at least the set first pulse and the second pulse;
A stepping motor controller comprising: The plurality of test pulses are continuously output so that the energy of the test pulse increases in order from the pulse with the lowest energy,
2. The control unit according to claim 1, wherein the control unit sets a test pulse corresponding to the predetermined amount of energy, which is less than the energy required to rotate the hands forward, as the first pulse. Stepping motor controller. The controller determines that the rotor has the predetermined amount of energy when an induced voltage generated by application of the test pulse is greater than a reference threshold voltage, and sets the test pulse as the first pulse. ,
3. The stepping motor control device according to claim 2. The control unit determines that the rotor has the predetermined amount of energy when the time required from the time of application of the test pulse to the time when an induced voltage greater than a reference threshold voltage is generated is equal to or longer than the determination period, and setting a pulse as the first pulse;
4. The stepping motor controller according to claim 2 or 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,
2. 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 by one polarity of the magnetic path. A timepiece comprising the stepping motor controller according to claim 1 and said hands. a step of outputting a plurality of first pulses having different energies 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 detecting the rotation state of the rotor according to the test pulse after each output of the plurality of test pulses;
setting a test pulse corresponding to the detected rotation state as the first pulse;
a step of reversely driving the pointer using at least the set first pulse and a second pulse having a polarity different from that of the first pulse;
A clock stepping motor control method comprising: When the stepping motor reverse rotation starts,
A first forward rotation driving pulse having a pulse length such that the stepping motor does not rotate in the predetermined forward direction is applied to the stepping motor, and the application of the first forward rotation driving pulse causes the stepping motor to rotate in the predetermined forward direction. determine whether or not
When the stepping motor does not rotate in the predetermined forward direction by applying the first forward rotation drive pulse, a second forward rotation drive pulse obtained by adding pulse energy to the first forward rotation drive pulse is applied. applying to the stepping motor and determining whether or not the stepping motor has rotated in a predetermined forward direction due to the application of the second forward rotation driving pulse;
determining a pulse length of a reverse drive pulse based on the pulse length of the second forward drive pulse when the stepping motor rotates in a predetermined forward direction by applying the second forward drive pulse;
adding the pulse energy and determining whether or not the stepping motor has rotated in the predetermined forward direction by applying the forward rotation drive pulse after the addition is repeated until the stepping motor rotates in the predetermined forward direction;
A clock stepping motor control method. The forward rotation drive pulse is repeatedly applied until the stepping motor rotates in the predetermined forward direction, and the reverse rotation drive pulse is not applied until the stepping motor rotates in the predetermined forward direction.
9. The timepiece stepping motor control method according to claim 8. determining the predetermined forward rotation when an induced voltage generated with the application of the first forward rotation drive pulse is greater than a reference threshold voltage;
10. The timepiece stepping motor control method according to claim 8 or 9. If the required time from the application of the first forward drive pulse to the generation of an induced voltage greater than a reference threshold voltage is equal to or greater than the determination period, the predetermined forward rotation is determined.
10. 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 that are continuously output is determined based on the energy of the drive pulse that is output to the stepping motor just before the first test pulse is output. is energy,
The stepping motor control device according to any one of claims 1 to 4. The polarity of at least one test pulse among the plurality of test pulses that are continuously output is different from the polarities of the other test pulses,
13. The stepping motor control device according to any one of claims 1 to 4 or 12. In the control unit, the time from application of the test pulse to application of the next test pulse is 15 ms or more.
14. The stepping motor control device according to any one of claims 1 to 4 or 12 to 13. When the energy of the test pulse is equal to or greater than a predetermined value and the induced voltage generated by the application of the test pulse is not greater than the reference threshold voltage, the energy of the first pulse and the second pulse is equal to or greater than the reference threshold voltage. applying a third pulse of predetermined energy and having the same polarity as the first pulse to the stepping motor;
15. The stepping motor control device according to any one of claims 1 to 4 or 12 to 14. When the pulse length of the first pulse set by the control unit is within a predetermined range, the first pulse set by the control unit is driven by the first pulse and the second pulse. is out of the predetermined range, the first pulse, the second pulse, and the second pulse having the predetermined energy and the same polarity as the first pulse. 3 pulses and
16. The stepping motor control device according to any one of claims 1 to 4 or 12 to 15.

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