JP2011033554A - Motor driving device and electronic clock - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor driving device and an electronic clock for reducing power consumption by increasing a selected optimal driving pulse. <P>SOLUTION: The motor driving device drives a stepping motor, and the electronic clock rotates an indicator by the motor driving device. Switching control of a pulse level is performed (condition St1 to condition St7), in which a driving pulse of one of two or more kinds of pulse levels P6 to P4 is output, and the pulse level is raised by one when non-rotating detection is performed, whereas the pulse level is dropped when rotation of predetermined number Nx is performed by a driving pulse of one thereof. Further, when conditions that determine selection of an optimal pulse level are met, number change control that increases the predetermined number Nx is performed (from condition St5 to condition St6). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a motor driving device for driving a stepping motor and an electronic timepiece having a stepping motor.

  In an electronic timepiece that displays the time by rotating the hands with a stepping motor, if the stepping motor is driven using a driving pulse having an excessive effective power, the power consumption for rotating the hands is unnecessarily increased.

  Therefore, in an electronic timepiece having a conventional stepping motor, in order to reduce power consumption, several types of stepping motor drive pulses are prepared, and a drive pulse having the minimum effective power necessary to rotate the pointer. The drive pulse selection control is performed so that is used (for example, Patent Documents 1 and 2).

  In the conventional drive pulse selection control, when the drive pulse is output and the stepping motor does not rotate, the drive pulse is changed to a drive pulse with a larger effective power, while the same type of drive pulse is output a specified number of times. When the stepping motor is not non-rotating, the driving pulse is changed to a driving pulse with a smaller effective power.

Japanese Patent No. 2753513 Japanese Patent No. 3832435

  In the conventional drive pulse selection control, every time the optimum drive pulse is output the specified number of times, even when the optimum drive pulse having the minimum effective power required to rotate the pointer is selected. As the rotation continues, the selection is switched to a drive pulse with a smaller effective power. Then, if the driving pulse is changed to one step smaller effective power, the stepping motor will not rotate, so a correction pulse that can obtain a reliable rotation is output to recover the rotation delay of the pointer, and then the non-rotating On the basis of the detection, the effective power is changed to one step higher and returned to the selection of the optimum drive pulse.

  That is, in the conventional drive pulse selection control, even when the optimum drive pulse is selected, the drive pulse selection is switched each time the drive pulse is output a specified number of times, and a correction pulse with a large power consumption is 1 There was a problem of being output twice.

  Further, in the conventional drive pulse selection control, the power supply voltage is temporarily reduced by another processing operation with a large load, and even when a drive pulse having a large effective power is selected due to this power supply voltage drop. If the specified number of drive pulses are not output, the selection is not switched to a drive pulse with a small effective power, so even if the power supply voltage recovers immediately thereafter, a drive pulse with a large power consumption is used for a relatively long time. There was a problem that it would end up.

  Similarly, in a device equipped with a power generation function, even if the power supply voltage recovers greatly due to power generation, if the specified number of drive pulses are not output, the selection is not switched to a drive pulse with a smaller effective power. There was a problem that a large drive pulse would be used for a relatively long time.

  An object of the present invention is to provide a motor driving device and an electronic timepiece that can reduce power consumption by selecting more optimal driving pulses.

In order to achieve the above object, the invention described in claim 1
In the motor drive device that drives the stepping motor,
Drive signal output means capable of outputting a plurality of types of drive signals having different effective powers to the stepping motor;
Rotation detection means for detecting whether the stepping motor is rotated or not rotated by the output of the drive signal;
Drive signal change control means for selectively switching the drive signal output from the drive signal output means to the stepping motor when the stepping motor is continuously rotated from the plurality of types of drive signals;
With
The drive signal change control means includes
Determination means for determining a lack of effective power of the drive signal output from the drive signal output means to the stepping motor based on the detection of non-rotation by the rotation detection means;
First change control means for changing the drive signal output from the drive signal output means to a drive signal having a large effective power when the determination means determines that the effective power of the drive signal is insufficient;
Output the same type of drive signal from the drive signal output means to the stepping motor for a set number of times, and output from the drive signal output means when the effective power of the drive signal is not determined to be insufficient by the determination means Second change control means for changing the drive signal to be changed to a drive signal with a small effective power;
Number change means for increasing or decreasing the set number based on a predetermined condition;
It is characterized by having.

The invention according to claim 2 is the motor drive device according to claim 1,
The number of times changing means is
The same type of drive signal is output when the set number of times, the drive signal output means outputs the same type of drive signal to the stepping motor, and the determination means does not determine that the effective power of the drive signal is insufficient. When the process is repeated, the set number of times is increased.

According to a third aspect of the present invention, in the motor driving device according to the first aspect,
The number of times changing means is
A drive signal that has been output for the set number of times without being determined that the effective power of the drive signal is insufficient by the determining unit is output for the set number of times without being determined that the effective power of the drive signal is insufficient by the determining unit. When the drive signal is the same type of drive signal as the most recent drive signal that has been continued, the set number of times is increased.

According to a fourth aspect of the present invention, in the motor drive device according to the first aspect,
The number of times changing means is
When the change to the drive signal with a large effective power by the first change control means and the change to the drive signal with a low effective power by the second change control means are alternately repeated once, the set number of times It is characterized by increasing.

The invention according to claim 5 is the motor drive device according to claim 2 or 3,
The rotation changing means is
When the change to the drive signal with a large effective power by the first change control means is performed twice in succession without the change to the drive signal with a small effective power by the second change control means, The set number of times is returned to a specified number.

The invention according to claim 6 is the motor drive device according to any one of claims 2 to 4,
The rotation changing means includes
When the change to the drive signal with small effective power by the second change control means is performed twice consecutively without interposing the change to the drive signal with large effective power by the first change control means, The set number of times is returned to a specified number.

The invention according to claim 7 is the motor drive device according to claim 1,
The determination means includes
When the non-rotation is detected once by the rotation detection means, it is determined that the effective power of the drive signal is insufficient.

The invention according to claim 8 is the motor drive device according to claim 1,
A process discriminating unit for discriminating an execution status of another driving process executed using a power source common to the driving power source of the stepping motor;
The number of times changing means is
When the determination means determines that the effective power of the drive signal is insufficient and the process determination means determines that the drive process is being executed or immediately after the execution, the set number of times is determined according to the drive process. It is characterized by changing the number of times.

The invention according to claim 9 is the motor drive device according to claim 7,
A set value storage means for storing the other drive process and the value of the set number of times corresponding to the drive process in association with each other;
The number of times changing means is
The set number of times is changed to a number according to the driving process based on data stored in the set value storage means.

The invention according to claim 10 is the motor drive device according to claim 1,
Power generation means;
Power storage means for charging the power generated by the power generation means and supplying driving power for the stepping motor;
Charging detection means for detecting the presence or absence of charging of the power storage means;
With
The number of times changing means is
When charging is detected by the charge detection means, the set value of the set number of times is changed to a number corresponding to charging.

The invention according to claim 11
Multiple pointers that rotate to display information,
A stepping motor for rotating the pointer;
The motor driving device according to any one of claims 1 to 10, which drives the stepping motor;
An electronic timepiece characterized by comprising:

  According to the present invention, the number of times the selection is switched to a drive signal with a small effective power is appropriately changed, so that a drive signal having an optimum execution power for driving the stepping motor is used more. As a result, the power consumption can be further reduced.

1 is a block diagram illustrating an overall configuration of an electronic timepiece according to a first embodiment of the present invention. It is a data chart which shows an example of a process-times correspondence table. It is a graph showing the relationship between the drive voltage and current consumption of the optimal drive pulse. It is a graph showing the relationship between the battery discharge amount of a power supply part, and a battery voltage. It is a graph showing the change of the battery voltage when a big load generate | occur | produces temporarily. It is a state transition diagram of the 1st example explaining the contents of the pulse control processing of an embodiment. It is a state transition diagram of the 2nd example explaining the contents of the pulse control processing of an embodiment. It is a state transition diagram of the 3rd example explaining the contents of the pulse control processing of an embodiment. It is a flowchart which shows the control procedure of the pulse control process performed by CPU of a control part. It is a block diagram which shows the whole structure of the electronic timepiece of 2nd Embodiment of this invention. It is a graph showing the relationship between the battery discharge amount of a power supply part, a battery voltage, and the output voltage of a constant voltage circuit. It is a flowchart which shows the control procedure of the pulse control process of 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a block diagram showing the overall configuration of the electronic timepiece according to the first embodiment of the present invention.

  The electronic timepiece 1 according to the first embodiment displays time by electrically rotating hands 11 such as an hour hand, a minute hand, and a second hand, and is a main body of a wristwatch, for example. As shown in FIG. 1, the electronic timepiece 1 includes a pointer 11, a stepping motor 13 that rotationally drives the pointer 11, a wheel train mechanism 12 that transmits the rotational motion of the stepping motor 13 to the pointer 11, and a stepping motor 13. Drive circuit 14 as drive signal output means for outputting a pulsed drive current, and rotation detection means for detecting the induced current generated in the stator coil after driving the stepping motor 13 and detecting the rotation or non-rotation of the stepping motor 13 As a rotation detector 15, a wheel train rotation position detector 16 for detecting whether or not the gear of the train wheel mechanism 12 has reached a predetermined rotation position for detecting the position of the pointer 11, and a power generation means such as a solar panel Power generation unit 17, charge detection unit 18 that measures the generated current to detect the presence or absence of charging, and a power generation unit that has a secondary battery as a power storage means The power from the accumulated and a power supply unit 19 for supplying an operating voltage to each unit.

  The electronic timepiece 1 has a CPU (Central Processing Unit) and a control unit 20 that performs overall control of the device, and a setting value in which a control program and control data executed by the CPU of the control unit 20 are stored. A ROM (Read Only Memory) 21 as a storage means, a RAM (Random Access Memory) 22 that provides a working memory space to the CPU of the control unit 20, and an oscillation circuit 23 that generates a timing signal having a constant cycle for timing. And a frequency dividing circuit 24, an alarm buzzer circuit 25, an illumination unit 26 for illuminating the dial of the electronic timepiece, an illumination drive circuit 27, and the like. Among these configurations, the drive circuit 14, the control unit 20, the rotation detection unit 15, the ROM 21, and the RAM 22 constitute a motor drive device. In addition, the control unit 20 constitutes a process determination unit that determines the execution status of other driving processes by controlling the operation of each unit.

  The stepping motor 13 has, for example, a two-pole rotor and a stator that rotates the rotor by winding a coil and causing a current to flow. The stepping motor 13 has a configuration in which the rotor rotates 180 ° each time by appropriately outputting appropriate positive polarity drive pulses and negative polarity drive pulses of effective power to the stator coil. The amount and pattern of the induced current generated in the stator coil after the output of the drive pulse differ between when the rotor is rotated 180 ° and when the execution power of the drive pulse is insufficient and the rotor does not rotate. The rotation detector 15 can detect the rotation and non-rotation of the stepping motor 13 by measuring the induced current.

  The drive circuit 14 receives a pulse signal from the control unit 20 and outputs the operating voltage supplied from the power supply unit 19 to the stator coil of the stepping motor 13 in correspondence with the pulse signal. The output of the drive circuit 14 is a drive pulse.

  In the train wheel rotation position detection unit 16, a photo interrupter having a light emitting unit such as a light emitting diode and a light receiving unit such as a photodiode is arranged with a plurality of gears of the wheel train mechanism 12 interposed therebetween. Then, it is detected whether or not the transmission holes provided in the plurality of gears of the train wheel mechanism 12 are arranged so as to overlap the detection position of the photo interrupter. The transmission hole of the gear is configured so that, for example, the transmission holes of the plurality of gears overlap the detection position of the photo interrupter when the plurality of hands 11 come to a predetermined rotational position. Therefore, by continuously driving the stepping motor 13 at high speed, operating the photo interrupter for each rotation of one step or two steps, and detecting the state where the transmission holes of the plurality of gears overlap the detection positions, It is possible to detect that the gear is at a predetermined rotational position, and that the plurality of hands 11 are at the predetermined rotational position. Such an operation of detecting the needle position is a process with a relatively large load because it requires continuous and high-speed driving of the stepping motor 13 and continuous driving of the light-emitting portion of the photo interrupter.

  The ROM 21 stores a pulse pattern table 21a and a process-times correspondence table 21b as control data.

  FIG. 2 shows a data chart showing a specific example of the processing-rotation correspondence table 21b.

  The processing-times correspondence table 21b is used when changing the setting number of times to lower the pulse level by one step in the pulse control process described later according to the immediately preceding load operation. In the processing-times correspondence table 21b, data representing a processing operation with a relatively large load and data of a set number of times corresponding to this processing operation are registered in association with each other. The processing operation includes illumination driving for lighting the illumination unit 26 for a certain period of time, buzzer sounding for operating the buzzer circuit 25 within a certain period of time, and switching the display by the pointer 11 from time display to other information display. Needle fast-forward processing (long-term, medium-term, short-term) for rotating at high speed, needle position detection processing (long-term, medium-term, short-term) using the above-described train wheel rotation position detection unit 16 are registered.

  The set number of times corresponding to each processing operation is designed to be a smaller value as the load is larger or as the load application time is longer. Although the details will be described later, the prescribed number of times that the pulse level is lowered by one step in the pulse control process is set to, for example, 100 times corresponding to the load of the normal time display, and the processing-times correspondence table 21b. The number of registered times is registered with a value smaller than the above-mentioned prescribed number of times (for example, 100 times) in order to correspond to a processing operation that requires a load larger than the load of the normal time display. .

  In the pulse pattern table 21 a stored in the ROM 21, a plurality of types of pattern data are registered for drive pulses for rotating the stepping motor 13. The control unit 20 reads one pattern data from the table 21a and outputs a pulse signal having a pattern according to the pattern data to the drive circuit 14, so that the drive voltage is applied from the drive circuit 14 in the pulse pattern. The drive pulse is output and the rotation control of the stepping motor 13 is performed.

  In the pulse pattern table 21a, a plurality of types of pattern data for changing the effective power of the driving pulse from a small level to a large level are registered. A single drive pulse for rotating the stepping motor 13 by one step is designed to be a signal in which a plurality of pulses are repeatedly output in an extremely short output period, for example. The plural types of pattern data are obtained by changing the output period of the drive pulse for one time and the duty ratio of the plural pulses, and are driven by the plural types of pattern data depending on the difference between the output period and the duty ratio. The effective power of the pulse changes step by step from small to large.

  FIG. 3 shows a graph showing the relationship between the drive voltage and current consumption of the optimum drive pulse.

  The types of drive pulses based on the plurality of types of pattern data are represented as pulse levels P1 to P6. The drive pulses of these pulse levels P1 to P6 have characteristics that the current consumption increases in order from the pulse level P1 to the pulse level P6 and the effective power increases stepwise if the drive voltage is constant.

  As shown by the dotted line in FIG. 3, the stepping motor 13 rotates with a small current when the driving voltage is high, whereas the stepping motor 13 does not rotate unless a large amount of current is supplied as the driving voltage decreases. Therefore, for example, when the drive voltage is high, for example, when the charge level of the battery of the power supply unit 19 is high, the pulse level P1 with low effective power is the optimum drive pulse. On the other hand, as the battery discharge progresses and the drive voltage becomes lower, the optimum drive pulse changes in turn to pulse levels P2 to P6 with larger effective power.

  FIG. 4 shows a graph showing the relationship between the battery voltage and the amount of battery discharge, and FIG. 5 shows a graph showing changes in the battery voltage when there is a temporary large load.

  As shown in FIG. 4, the secondary battery of the power supply unit 19 has a high battery voltage when the charge level is high, while the battery voltage decreases as the discharge proceeds. Further, a substantially stable battery voltage is supplied when the charge level is intermediate.

  On the other hand, as shown in FIG. 5, when there is a large load, the battery voltage is lower than the primary stable voltage, and it takes some time to return to the original stable voltage.

  In the first embodiment, the battery voltage of the power supply unit 19 is pulsed by the drive circuit 14 and output to the stepping motor 13.

  The control program stored in the ROM 21 counts the time based on the signal from the frequency dividing circuit 24 and time display processing program for driving the hands 11 so that the time data value and the position of the hands 11 are synchronized. , A pulse control process program for switching drive pulses during the time display process, a needle fast-forward process program for fast-forwarding the pointer 11 to display information different from the time display, and a hand position for detecting the position of the pointer 11 Predetermined control actions (lighting drive, alarm ringing, needle fast feed, needle position detection, etc.) based on detection processing program, occurrence of predetermined conditions (such as when user input or time data reaches a set value) The program of the operation | movement distribution process which operates is included. The CPU of the control unit 20 that executes the above-described pulse control processing program constitutes drive signal change control means.

[Pulse control processing]
Next, a pulse control process executed by the electronic timepiece 1 having the above configuration will be described. The pulse control process is performed in each situation so that the most suitable drive pulse for rotating the stepping motor 13, that is, the drive pulse that minimizes the effective power without the stepping motor 13 not rotating is used. This is a process of selectively switching the drive pulses of the pulse levels P1 to P6 in response to this, and is performed by the control unit 20.

  FIG. 6 to FIG. 8 show state transition diagrams of first to third examples for explaining the contents of the pulse control processing of the present embodiment.

The pulse control process of this embodiment is mainly configured by a combination of the following five controls A to E.
A. When the driving pulse is output and the stepping motor 13 is detected to be non-rotating, the control is changed to a driving pulse whose effective power is one step higher than the current driving pulse. Control for changing to a drive pulse whose effective power is one step lower than the current drive pulse if the set number of times Nx and the drive pulse are output and no rotation is detected at all. When the condition for determining that the optimal drive pulse is selected is satisfied, the value of the set number of times Nx is increased. On the other hand, when the condition for determining that the optimal drive pulse is unknown is satisfied, Control for returning the value Nx of the set number of times to a specified number of times (for example, 100 times) D. Control for returning the set number of times Nx to a specified number when the charge detection unit 18 detects that the battery is being charged E. When the stepping motor 13 is detected to be non-rotating and a load operation has been performed immediately before, the above-mentioned set number Nx is changed to a number corresponding to the previous load operation according to the processing-number correspondence table 21b.

  During the above control, when the driving pulse is output and the stepping motor 13 is detected to be non-rotating, a correction pulse with a large execution power that can be surely rotated to eliminate the rotation delay due to the non-rotation. The stepping motor 13 is driven to rotate.

  Among the above-mentioned controls A to E, the condition for increasing the value of the set number Nx in the control C is as follows. That is, this is the case where the most recent pulse level that has cleared the rotation of the set number of times Nx (all rotated) and the pulse level that has cleared the rotation of the set number of times Nx are the same. Under normal operating conditions, once the rotation of the set number of times Nx is completed with the optimum pulse level, the pulse level is once lowered by one step and non-rotation is detected. Then, by detecting this non-rotation, the rotation is returned to the optimum pulse level again and the rotation of the set number of times Nx is cleared. At this time, the current pulse level that has cleared the rotation of the set number of times Nx is the same as the latest pulse level that has cleared the rotation of the set number of times Nx. The value of Nx is increased by, for example, “100”.

  Then, by repeating the control for increasing the value of the set number Nx, the set number Nx increases to “100”, “200”, “300”. It can be increased.

  On the other hand, in the above control C, there are two conditions for returning the increased set number Nx to the specified number (100), one of which is the latest pulse level that cleared the rotation of the set number Nx, and thereafter This is a case where non-rotation is detected during the driving process. Furthermore, the other is a condition that the latest pulse level that has cleared the rotation of the set number of times Nx is different from the pulse level that has cleared the rotation of the set number of times Nx.

  Here, an example of the pulse level change control and the set number Nx change control by the above-described controls A to C will be described with reference to the state transition diagrams of FIGS.

  For example, when the optimum drive pulse is the pulse level P4 and the pulse level P6 is selected and the drive control of the stepping motor 13 is started, as shown in FIG. 6, in the initial state St1, the output of the pulse level P6 The stepping motor 13 rotates at all of the specified number of times Nx (= 100). Based on this, the pulse level is switched by the control B, the execution power is changed to the pulse level P5 that is one step lower, and the state shifts to St2. Subsequently, similarly, in the state St2, the set number of times Nx is rotated by the driving pulse of the pulse level P5, so that the driving pulse is lowered by one step to the pulse level P4 by the control B, and the state St3 is shifted. Since the set number of times Nx is rotated by the drive pulse at the pulse level P4, the drive pulse is lowered by one step to the pulse level P3 by the control B, and the state shifts to St4.

  In the state St4 in which the pulse level P3 lower than the optimum level is selected, the effective power of the drive pulse is insufficient, so that the stepping motor 13 is not rotated before reaching the first output or the set number Nx output. Then, based on the detection of non-rotation, the drive pulse is returned to the pulse level P4 by the control A, and the state shifts to St5. Then, again, rotation is performed 100 times by the driving pulse having the optimum pulse level P4 in the state St5.

  Here, the pulse level P4 (state St5) that has cleared the rotation of the set number of times Nx is the same as the pulse level P4 (state St3) that has recently cleared the rotation of the set number of times Nx. That is, the condition for increasing the set number Nx by the control C is satisfied. Therefore, since it can be determined that the pulse level P4 is optimal, the set number Nx is incremented by “100” to “200” in the subsequent state St6.

  In the state St6, non-rotation is detected by the driving pulse of the pulse level P3, but when the state is returned to the optimum pulse level P4 in the subsequent state St7, the set number Nx is increased to “200”. It is possible to increase the number of times that the drive pulse of the optimum pulse level P4 is output. That is, after the rotation of the set number of times Nx is performed at the optimum pulse level P4, the effective power is switched to the drive pulse of the pulse level P3 that is one step lower, and thereby the non-rotation is generated and the correction pulse is output. The frequency of occurrence can be reduced.

  Subsequently, as shown in FIG. 7, since the most recent drive pulse that has cleared the rotation of the set number Nx is the pulse level P4, it is set every time the states St11, St12, St13 and the pulse levels P4, P3 are switched alternately. The number of times Nx is increased to “300” and “400”.

  Here, for example, it is assumed that the battery voltage is lowered, and the effective power is insufficient at the pulse level P4 that has been optimized so far. Then, in the state St14, the stepping motor 13 is not rotated at the x-th output before reaching the set number Nx. Based on this non-rotation detection, the drive pulse is switched to the pulse level P5 by the control A, and the state St15 is obtained. In this case, since the condition for returning the set number Nx to the specified number is satisfied by the control C and it can be determined that the optimum pulse level is unknown, the set number Nx is returned to the specified number (for example, 100) in the state St15. It is.

  Further, as shown in FIG. 8, the most recent drive pulse that has cleared the set number Nx of rotations is at the pulse level P4, and the states St21, St22, St23 and the pulse levels P4, P3 are alternately switched and set. After the number of times Nx is increased to “300” and “400”, for example, it is assumed that the battery voltage rises due to some state change and the optimum pulse level changes. In this case, the rotation of the set number Nx is cleared in the state St23 where the output of the pulse level P3 is performed. Then, since the rotation of the set number Nx is cleared, the drive pulse is lowered by one step to the pulse level P2 by the control B, and the state shifts to St24. Further, since the most recent drive pulse that cleared the rotation of the set number of times Nx was the pulse level P4, the drive pulse that cleared the rotation of the set number of times Nx is different from the pulse level P3. The condition for returning Nx to the specified number of times is satisfied, and the set number of times Nx is returned to the specified number of times (for example, 100 times) in the state St24.

  As described above, if the conditions for outputting the drive pulse that can be determined to be the optimum pulse level are obtained by the pulse level selection control by the controls A and B and the change control of the set number Nx by the control C, the set number Nx Is increased. Therefore, in the situation where the optimum pulse level is output, the frequency at which the correction level is output by changing the pulse level can be reduced. On the other hand, if it becomes a condition that the optimum pulse level can be determined to be unknown by changing the power supply voltage, the set number Nx is returned to the specified number (100 times) and the transition to the optimum pulse level can be made relatively quickly. It becomes possible.

  In addition, among the above-described controls A to E, the change control of the set number Nx by the control D is because the optimum pulse level can be determined to be unknown by charging the secondary power of the power supply unit 19 and the like. Is executed as As shown in FIG. 4, when the secondary battery of the power supply unit 19 is charged and the charge level is increased, the battery voltage may rise relatively large. If the battery voltage rises, the optimum pulse level is also changed. Therefore, in such a case, the set number of times Nx is returned to the specified number (100 times), and the transition to the optimum pulse level can be made promptly.

  Among the controls A to E, the change control of the set number Nx by the control E is because it can be determined that the optimum pulse level changes in a relatively short period when a relatively large load operation is performed. Is executed as As shown in FIG. 5, when a large load operation is performed, the battery voltage fluctuates with a constant fluctuation amount in a certain period according to the magnitude of the load operation and the period of the load operation. The period during which the optimum pulse level changes varies depending on the fluctuation range of the battery voltage and the period until the battery voltage recovers. Accordingly, the set number corresponding to each load operation is read from the processing-number correspondence table 21b of the ROM 21 and set as the set number Nx used for the subsequent pulse control.

  For example, when the stepping motor 13 is not rotated and the illumination drive is executed immediately before, the set number of times “30” corresponding to the illumination drive registered in the process-number correspondence table of FIG. This number is set as a set number Nx for lowering the pulse level by one step. Further, for example, if the immediately preceding load operation is a fast-forward operation of the pointer 11 in the middle period, for example, the set number “60” is read, and if the short-term hand position detection operation is set, the set number “70” is read. Set as number of times Nx.

  By changing the set number of times Nx, when the power supply voltage once decreases due to a large load operation and then rises again to return to a stable voltage, it is changed to the set number of times Nx corresponding to the load operation. In response to fluctuations in the increase and decrease of the power supply voltage, it is possible to quickly transition to the optimum pulse level thereafter.

  Next, a control procedure of the pulse control process for realizing the above-described pulse level selection control will be described based on a flowchart.

  FIG. 9 shows a flowchart of a pulse control process executed by the CPU of the control unit 20. In this flowchart, Nc is the number of times the stepping motor 13 is continuously driven at the current pulse level, Nx is a set number of times that the pulse level is controlled to be lowered by one step when all the rotations are performed by the control B, and N0 is the above control. In the case of all rotations in B, the specified number of times that becomes the initial value of the set number of times to lower the pulse level by one step, NL is the set number of times corresponding to the load operation registered in the process-number correspondence table 21b, and Nmax is the set number of times Nx Px is the pulse level of the currently selected drive pulse, Ps is the latest pulse level that has cleared the rotation of the set number Nx, and is the pulse level held as the optimal candidate.

  This pulse control process is started when the electronic timepiece 1 is powered on, and is executed in parallel with the clock display process and other control processes by the CPU of the control unit 20. Then, the timing of rotating the hands 11 step by step in the time display process, and whenever there is a drive request for the stepping motor 13, the process proceeds to step S1 and proceeds.

  In step S1, first, the CPU of the control unit 20 outputs a pulse signal to the drive circuit 14 at the currently selected pulse level Px (the initial value may be any pulse level) (step S1). . As a result, a drive pulse having a pulse level Px is output to the stepping motor 13. Next, the CPU inputs a detection signal from the rotation detector 15 and obtains a rotation detection result (step S2). Then, it is determined whether or not the rotor of the stepping motor 13 has rotated (step S3: determination means for determining whether the effective power is insufficient). If it is rotating, the process proceeds to step S4, and if it is not rotating, the process proceeds to step S7. Branch.

  If it is determined as a result of the rotation, it is subsequently determined whether charging is in progress based on a detection signal from the charge detection unit 18 (step S4). If charging is being performed, the set number Nx is set to a specified number N0 (for example, 100 times) (step S5: number changing means), and the driving number Nc is counted up (step S6). If not charging, the drive count Nc is counted up as it is (step S6).

  On the other hand, if the non-rotation is determined in the determination process of step S3, first, a correction pulse is output to the drive circuit 14 to compensate for the rotation delay of the stepping motor 13 (step S7), and then a large load operation is performed immediately before. It is confirmed whether or not it has been performed (step S8). Since the load operation is performed under the control of the CPU of the control unit 20, it can be confirmed whether or not the load operation has been performed immediately before by the CPU. If the load operation has been performed immediately before, the corresponding set number of times NL is read from the processing-number of times correspondence table 21b and set as the set number of times Nx (step S11: number of times changing means). Then, the process proceeds to step S12.

  If it is determined in the determination process in step S8 that the load operation has not been performed immediately before, it is determined whether or not the current pulse level Px is the pulse level Ps held as the optimal candidate (step S9). If so, the set number Nx is returned to the specified number N0 (step S10: number change means). Then, the process proceeds to step S12.

  If both of the determination processes in steps S8 and S9 determine “NO”, the set number of times Nx is not changed and the process proceeds to step S12.

  When the process proceeds to step S12, since the current pulse level Px is not rotating, the pulse level is increased by one step to “Px + 1”, and the pulse level is changed, so that the count value of the drive count Nc is set to “0”. (Step S12: first change control means).

  After the process of step S6 or step S12 is performed, it is then determined whether or not the count value of the drive count Nc has exceeded the set count Nx (step S13). If not exceeded, it waits until there is a request for driving the next pointer 11 (step S20), and returns to step S1.

  On the other hand, if it is determined in step S13 that the current driving number Nc exceeds the set number Nx, it means that the set number Nx has been rotated, so first, the current pulse level Px. Is the same as the pulse level Ps held as the optimal candidate (the latest pulse level that has cleared the rotation of the set number Nx) (step S14).

  As a result, if they are the same, it can be determined that the pulse level Px is the optimum pulse level. Therefore, after confirming whether the current set number Nx is the maximum number Nmax (step S17), Is increased by “100” (step S18: number changing means).

  If they are not the same, the current pulse level Px is held as the optimal candidate pulse level Ps (step S15), and the set number Nx is returned to the specified number N0 (step S16: number changing means).

  After step S18 or step S16, the pulse level Px is reduced by one step to “Px−1” based on the fact that the set number of times Nx has been rotated, and the pulse level is changed. Reset to “0” (step S19: second change control means).

  Then, it waits until there is a request for driving the next pointer 11 (step S20), and returns to step S1.

  According to the above-described pulse control processing, in a situation where a pulse level Px with sufficiently high effective power is output, the processing loop of steps S1 to S6, S13, and S20 is repeated a set number of times Nx, and the pulse level Px is reached. Rotation occurs at all the set times Nx. If the pulse level Px is much higher than the optimum level, the process proceeds to steps S14 to S16, S19, and the pulse level Px is held as the latest pulse level Ps that has cleared the set number Nx of rotations. Further, the set number Nx is set to the prescribed number N0, and the pulse level is set to one paragraph. That is, the selection control of the control B described above is performed.

  In a situation where the pulse level Px with insufficient effective power is output, the process proceeds to steps S1 to S3, S7 to S9, S12, and S13, and the pulse level is increased by one stage. That is, the selection control of the control A described above is performed.

  Further, in a situation where the output of the optimum pulse level Px and the process of detecting the rotation at all the set number Nx and the process of lowering the pulse level by one step are repeated, step S1 is performed based on the driving at the optimum pulse level Px. The processing loop of S6, S13, and S20 is repeated for the set number of times Nx, and then the process proceeds to steps S14, S17, and S18 to increase the set number of times Nx. In other words, the above-described increase control of the set number Nx of the control C is performed, and then the frequency of the event in which the pulse level is lowered by one step and the correction pulse is output is reduced.

  Further, in the situation where the optimum pulse level is unknown due to a decrease in battery voltage or the like when the pulse level Px having the optimum effective power is being output, the process proceeds to steps S1 to S3 and S7 to S10. The set number Nx is returned to the specified number N0. In other words, the above-described reduction control of the set number Nx of the control C is performed.

  In a situation where the battery voltage rises due to charging and the optimum pulse level is unknown, or in a situation where the battery voltage varies due to a large load operation, the processing in steps S4 and S5 and the processing in steps S8 and S11 are performed. The set number Nx is changed as appropriate. That is, the above-described control for changing the number of times of controls D and E is performed.

  As described above, according to the electronic timepiece 1 and the motor driving device (the driving circuit 14, the control unit 20, the rotation detecting unit 15, the ROM 21, and the RAM 22) of this embodiment, the pulse level is lowered by one step by rotating all. The set number of times Nx is increased by a condition that can be determined to be the optimum pulse level, and is returned to the specified number of times by a condition that the optimum pulse level can be determined to be unknown. Therefore, in a situation where the optimum pulse level is selected, the frequency of occurrence of a situation in which the pulse level is lowered and a correction pulse is output by non-rotation can be reduced. Further, when the optimum pulse level changes due to fluctuations in the power supply voltage, the optimum pulse can be selected quickly.

  Further, according to the electronic timepiece 1 and the motor drive device of this embodiment, the pulse level determined to be the rotation at all the set number Nx is the same as the latest pulse level determined to be the rotation at all the set number Nx. Since the set number of times Nx is increased, the optimum pulse level can be determined accurately and the optimum pulse level can be used more frequently.

  As shown in FIGS. 6 to 8, when the state determined to rotate at all the set number Nx is repeated with the same pulse level, the set number Nx is increased or the set number Nx Even if the set number of times Nx is increased when the control in which all are determined to be rotation and the control in which the pulse level is lowered by one step and the control in which the pulse level is determined to be non-rotation and the pulse level is increased by one step are repeated. In addition, the optimum pulse level can be accurately determined so that the optimum pulse level is used more frequently.

  Further, according to the electronic timepiece 1 and the motor driving device of this embodiment, the pulse level determined to be rotated at all the set times Nx is different from the latest pulse level determined to be rotated at all the set times Nx. 7 or 8, as shown in FIGS. 7 and 8, the states St13 and St14 that are determined to be non-rotation before reaching the set number Nx are continued twice, or the rotation is determined at all the set times Nx. When the states St22 and St23 continue twice, the set number of times Nx is returned to the specified number of times, so that it is accurately determined that the optimum pulse level is unknown, and the optimum pulse level is selected promptly. Can be.

  Further, according to the electronic timepiece 1 and the motor driving device of this embodiment, when one non-rotation is detected, it is determined that the effective power is insufficient at the pulse level used at that time. Therefore, it is possible to simplify the determination of the lack of effective power and the selection control of the pulse level based on it. Note that the determination that the effective power of the drive pulse is insufficient is not detected as one non-rotation, for example, when the non-rotation is continued twice, or the frequency of non-rotation exceeds a certain level. It can be changed in various ways.

  Further, according to the electronic timepiece 1 and the motor driving device of this embodiment, when a large load operation is performed and non-rotation is detected, the number of times is changed to the set number Nx corresponding to the load operation. Corresponding to the fluctuation of the power supply voltage based on the load operation, the transition to the optimum pulse level can be made promptly.

  Further, since the change control of the set number of times Nx corresponding to the load operation is performed based on the data of the processing-number correspondence table, the optimum number of times corresponding to the size of the load and the execution period of the load operation is set to the set number of times Nx. Can be applied as

  In addition, when charging is detected, the set number Nx is returned to the specified number, so that when the power supply voltage rises due to charging and the optimum pulse level changes, this optimum pulse is changed. Transitions to levels can be made promptly.

[Second Embodiment]
FIG. 10 is a block diagram showing the overall configuration of the electronic timepiece according to the second embodiment of the present invention, and FIG. 11 shows the relationship between the battery discharge amount of the power supply unit, the battery voltage, and the output voltage of the constant voltage circuit. FIG. 12 is a flowchart of the pulse control process according to the second embodiment.

  In the electronic timepiece 1A of the second embodiment, the constant voltage circuit 29 is added to that of the first embodiment, and even if the battery voltage of the power supply unit 19 rises, the operating voltage supplied to each part is kept constant. It is what I did.

  As shown in FIG. 11, the constant voltage circuit 29 converts the battery voltage of the power supply unit 19 into a constant voltage and outputs it. When the battery voltage decreases, the output of the constant voltage circuit 29 also decreases. However, when the battery voltage becomes high, a constant voltage is output.

  In the second embodiment, since the constant voltage circuit 29 is provided, the voltage of the drive pulse does not increase even when the secondary battery of the power supply unit 19 is charged. Therefore, the setting based on the charge detection is performed. The change control (control D) of the number of times Nx is omitted.

  That is, as shown in the flowchart of FIG. 12, in the pulse control process of the second embodiment, steps S4 and S5 for changing the set number Nx based on the charge detection of FIG. 9 are omitted, and the others are the first embodiment. It is similar to that of the form.

  As described above, even in the configuration including the constant voltage circuit 29, the selection control of the pulse level of the control A to the control C and the control E and the change control of the set number Nx are performed as in the first embodiment. The optimal pulse level can be used more frequently.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, as the predetermined condition for increasing the set number Nx, in addition to those shown in the above embodiment, the effective power at the pulse level is immediately determined after the pulse level is lowered by one step after it is determined that the set number Nx is all rotations. Various conditions can be set for determining an optimum pulse level, such as when it is determined that the pulse is insufficient.

  In the above embodiment, the control is performed so that the set number of times Nx is returned to the specified number when the charge is detected or when the condition that the optimum pulse level can be determined to be unknown is satisfied. In such a case, it is possible to control to return to a small number different from the specified number of times or to reduce the predetermined number of times.

  In the above embodiment, a single stepping motor is shown. However, if a plurality of stepping motors are used to drive a plurality of hands separately, drive pulse selection control is performed for each stepping motor. You can also.

  Other details such as the pulse pattern of the drive pulse, the number of selectable pulse patterns, the specified number of set times Nx, the amount to increase or decrease the set number Nx, the rotation detection method of the stepping motor, etc. Changes can be made as appropriate without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1,1A Electronic timepiece 11 Pointer 13 Stepping motor 14 Drive circuit 15 Rotation detection part 17 Power generation part 18 Charge detection part 19 Power supply part 20 Control part 21 ROM
21a Pulse pattern table 21b Processing-times correspondence table 22 RAM
29 Constant voltage circuit

Claims (11)

In the motor drive device that drives the stepping motor,
Drive signal output means capable of outputting a plurality of types of drive signals having different effective powers to the stepping motor;
Rotation detection means for detecting whether the stepping motor is rotated or not rotated by the output of the drive signal;
Drive signal change control means for selectively switching the drive signal output from the drive signal output means to the stepping motor when the stepping motor is continuously rotated from the plurality of types of drive signals;
With
The drive signal change control means includes
Determination means for determining a lack of effective power of the drive signal output from the drive signal output means to the stepping motor based on the detection of non-rotation by the rotation detection means;
First change control means for changing the drive signal output from the drive signal output means to a drive signal having a large effective power when the determination means determines that the effective power of the drive signal is insufficient;
Output the same type of drive signal from the drive signal output means to the stepping motor for a set number of times, and output from the drive signal output means when the effective power of the drive signal is not determined to be insufficient by the determination means Second change control means for changing the drive signal to be changed to a drive signal with a small effective power;
Number change means for increasing or decreasing the set number based on a predetermined condition;
A motor drive device comprising: The number of times changing means is
The same type of drive signal is output when the set number of times, the drive signal output means outputs the same type of drive signal to the stepping motor, and the determination means does not determine that the effective power of the drive signal is insufficient. The motor driving apparatus according to claim 1, wherein the number of times of setting is increased when the operation is repeated. The number of times changing means is
A drive signal that has been output for the set number of times without being determined that the effective power of the drive signal is insufficient by the determining unit is output for the set number of times without being determined that the effective power of the drive signal is insufficient by the determining unit. 2. The motor drive device according to claim 1, wherein the set number of times is increased when the drive signal is the same type of drive signal as the latest drive signal that has been continued. The number of times changing means is
When the change to the drive signal with a large effective power by the first change control means and the change to the drive signal with a low effective power by the second change control means are alternately repeated once, the set number of times The motor driving device according to claim 1, wherein the motor driving device is increased. The rotation changing means includes
When the change to the drive signal with a large effective power by the first change control means is performed twice in succession without the change to the drive signal with a small effective power by the second change control means, The motor drive device according to claim 2, wherein the set number of times is returned to a specified number. The rotation changing means is
When the change to the drive signal with small effective power by the second change control means is performed twice consecutively without interposing the change to the drive signal with large effective power by the first change control means, The motor driving apparatus according to claim 2, wherein the set number of times is returned to a specified number. The determination means includes
2. The motor drive device according to claim 1, wherein when the non-rotation is detected once by the rotation detection means, it is determined that the effective power of the drive signal is insufficient. A process discriminating unit for discriminating an execution status of another driving process executed using a power source common to the driving power source of the stepping motor;
The number of times changing means is
When the determination means determines that the effective power of the drive signal is insufficient and the process determination means determines that the drive process is being executed or immediately after the execution, the set number of times is determined according to the drive process. The motor driving device according to claim 1, wherein the motor driving device is changed to a number of times. A set value storage means for storing the other drive process and the value of the set number of times corresponding to the drive process in association with each other;
The number of times changing means is
8. The motor drive apparatus according to claim 7, wherein the set number of times is changed to a number according to the drive process based on data stored in the set value storage means. Power generation means;
Power storage means for charging the power generated by the power generation means and supplying driving power for the stepping motor;
Charging detection means for detecting the presence or absence of charging of the power storage means;
With
The number of times changing means is
2. The motor driving apparatus according to claim 1, wherein when the charging detection unit detects that there is charging, the set value of the set number of times is changed to a number corresponding to charging. Multiple pointers that rotate to display information,
A stepping motor for rotating the pointer;
The motor driving device according to any one of claims 1 to 10, which drives the stepping motor;
An electronic timepiece characterized by comprising:

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