JP2014027783A - Stepping motor control circuit, movement, and analog electronic clock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To demagnetize a stepping motor without rotating it by driving the motor with appropriate energy demagnetization pulses after driving with correction drive pulses when an event has occurred causing demagnetization pulse energy to fluctuate widely.SOLUTION: According to the revolving condition of a stepping motor 109 detected by a rotation detection circuit 107 and a detection interval determination circuit 111, a control unit selects a main drive pulse or a correction drive pulse having larger energy than the main drive pulse and drives the stepping motor 109 with the selected pulse. Also, if, when the stepping motor is to be driven with a demagnetization pulse immediately after being driven with the correction drive pulse, it is determined that the energy of the demagnetization pulse will become out of range, the control unit changes it to a demagnetization pulse having energy within a prescribed range.

Description

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

Conventionally, stepping motors have been used for applications such as driving time hands of analog electronic timepieces. When driving the stepping motor, the stepping motor is normally driven by the main drive pulse P1, and when the stepping motor cannot be rotated by the main drive pulse P1, a correction drive pulse having a larger energy than the main drive pulse P1. It is driven by a method of forcibly rotating by P2.
Since the correction drive pulse P2 has a large energy, residual magnetic flux remains after driving with the correction drive pulse P2, which may affect the next driving of the main drive pulse P1 and cannot rotate normally.

  Conventionally, a method of driving with a demagnetizing pulse PE is used to demagnetize the residual magnetic field immediately after driving with the correction driving pulse P2. This method is used because the effective magnetic field due to the driving with the main driving pulse P1 is reduced unless the demagnetizing pulse PE is driven. However, if the energy of the demagnetizing pulse PE is too large, There is a problem that the stepping motor rotates due to the driving by the demagnetizing pulse PE, and the rotation timing differs. Therefore, the demagnetizing pulse PE needs to be a pulse having such energy that the residual magnetic flux can be demagnetized and does not rotate.

  However, when a power source (for example, a secondary battery) whose voltage greatly varies is used as the power source, if the degaussing pulse PE is optimized for a low power source voltage, if the power source voltage is high, the degaussing pulse There is a problem that the rotor rotates due to excessive energy. Conversely, if the demagnetization pulse PE is optimized in accordance with a high power supply voltage, there is a problem that when the power supply voltage is low, the energy of the demagnetization pulse PE becomes too small to demagnetize.

Japanese Patent Publication No. 61-15385

  The present invention has been made in view of the above problems, and even when a situation occurs in which the energy of the degaussing pulse greatly fluctuates, by driving with a correction driving pulse and then driving with a degaussing pulse having an appropriate energy. The problem is to degauss without rotating the stepping motor.

  According to a first aspect of the present invention, a power source, a rotation detection unit that detects a rotation state of the stepping motor, and a main drive pulse or the main drive pulse depending on the rotation state detected by the rotation detection unit And a control unit that drives the stepping motor by selecting a correction drive pulse having a large energy, and that is driven by a demagnetization pulse immediately after being driven by the correction drive pulse. A stepping motor control circuit is provided, wherein the stepping motor control circuit changes to a degaussing pulse of energy within the predetermined range when it is determined that it is outside the predetermined range.

  According to a second aspect of the present invention, there is provided a movement comprising the stepping motor control circuit.

  According to a third aspect of the present invention, there is provided an analog electronic timepiece comprising the movement.

According to the stepping motor control circuit according to the present invention, even when a situation in which the energy of the demagnetizing pulse greatly fluctuates, it can be driven by the demagnetizing pulse of appropriate energy after being driven by the correction driving pulse. It becomes possible to degauss well without rotating the stepping motor.
Further, according to the movement according to the present invention, even when a situation where the energy of the degaussing pulse greatly fluctuates, the stepping motor can be driven with the demagnetizing pulse having an appropriate energy after being driven with the correction driving pulse. It becomes possible to demagnetize well without rotating.
Further, according to the analog electronic timepiece according to the present invention, even when a situation where the energy of the demagnetization pulse greatly fluctuates, it can be driven by the demagnetization pulse of appropriate energy after being driven by the correction drive pulse. Demagnetization can be satisfactorily performed without rotating the stepping motor, and accurate hand movement becomes possible.

It is a block diagram common to the 1st and 2nd embodiment of this invention. It is a block diagram of the stepping motor used for each embodiment of the present invention. It is a timing diagram for demonstrating operation | movement of each embodiment of this invention. It is a timing diagram for demonstrating operation | movement of each embodiment of this invention. It is a timing diagram for demonstrating operation | movement of the 1st, 3rd Embodiment of this invention. It is a timing diagram for demonstrating operation | movement of the 1st, 3rd Embodiment of this invention. It is a flowchart of the 2nd Embodiment of this invention. It is a timing diagram for demonstrating the operation | movement of the 2nd Embodiment of this invention. It is a timing diagram for demonstrating the operation | movement of the 2nd Embodiment of this invention. It is a block diagram of the 3rd Embodiment of this invention. It is a flowchart of the 3rd Embodiment of this invention. It is a flowchart of the 3rd Embodiment of this invention.

Hereinafter, a stepping motor control circuit, a movement, and an analog electronic timepiece according to an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same parts are denoted by the same reference numerals.
FIG. 1 is a block diagram of a stepping motor control circuit, a movement, and an analog electronic timepiece according to the first and second embodiments of the present invention, and shows an example of an analog electronic wristwatch.
In FIG. 1, an analog electronic timepiece includes an oscillation circuit 101 that generates a signal of a predetermined frequency, a frequency dividing circuit 102 that divides the signal generated by the oscillation circuit 101 and generates a clock signal that serves as a time reference, and an electronic timepiece. A control circuit 103 that performs control of each electronic circuit element that constitutes, control of change of drive pulse, etc., and pulse down for pulse-down of the main drive pulse P1 every time a clock signal from the frequency divider circuit 102 is timed. A pulse down counter circuit (PCD counter) 105 is provided which outputs a control signal and resets the count value in response to a reset signal from the control circuit 103 and then starts a time counting operation again.

  Further, the analog electronic timepiece selects a main drive pulse generation circuit 104 that selects and outputs one of a plurality of types of main drive pulses P1 having different energy based on a main drive pulse control signal from the control circuit 103, and a control circuit. A correction drive pulse generation circuit 108 that outputs a correction drive pulse P2 having energy larger than each main drive pulse P1 based on a correction drive pulse control signal from 103, and a stepping motor based on a demagnetization pulse control signal from the control circuit 103 A degaussing pulse generation circuit 114 that outputs a degaussing pulse for degaussing 109 is provided.

The analog electronic timepiece responds to the main drive pulse P1 from the main drive pulse generation circuit 104, the correction drive pulse P2 from the correction drive pulse generation circuit 108, and the demagnetization pulse PE from the demagnetization pulse generation circuit 114. Motor driving circuit 106 and stepping motor 109 are provided.
The analog electronic timepiece is disposed on the outer side of the timepiece case 116, the timepiece case 116, the analog display unit 110 having the time hand 115 driven by the stepping motor 109, and the movement 117 provided in the timepiece case 116. It has.

  The analog electronic timepiece is based on a rotation detection circuit 107 and a rotation detection circuit 107 that detect an induced signal VRs generated by free vibration after driving the stepping motor 109 and exceeding a predetermined reference threshold voltage Vcomp in a predetermined detection section T. A detection section determination circuit 111 that determines in which section in the detection section T the induced signal VRs exceeding the threshold voltage Vcomp is detected.

As will be described later, the detection section T that detects the rotation state of the stepping motor 109 is provided immediately after the driving of the stepping motor 109 is stopped, and is divided into a plurality of sections (three sections T1 to T3 in this embodiment). Has been.
The battery 112 is a power source for the analog electronic timepiece, and functions as a power source that supplies power to at least the stepping motor 109. The battery 112 may be either a primary battery or a secondary battery.

  The rotation discriminating circuit 111 determines which section in the detection section T the induced signal VRs exceeding the reference threshold voltage Vcomp detected by the rotation detection circuit 107 is detected, and the induced signal VRs exceeding the reference threshold voltage Vcomp is detected. Based on the combination pattern of the sections (pattern of the induced signal VRs), a detection signal indicating the degree of driving energy margin and a rotation state such as non-rotation is output to the control circuit 103.

Oscillation circuit 101, frequency divider circuit 102, control circuit 103, main drive pulse generation circuit 104, correction drive pulse generation circuit 105, demagnetization pulse generation circuit 114, motor drive circuit 106, stepping motor 109, rotation detection circuit 107, rotation discrimination circuit 111 and the battery 112 are components of the movement 117.
In general, a timepiece mechanical body composed of devices such as a timepiece power source and a time reference is called a movement. Electronic devices are sometimes called modules. When the watch is completed, a dial and hands are attached to the movement and housed in a watch case.

  The control circuit 103 resets the pulse down counter circuit 105 under a certain condition and restarts the count operation from the initial value, and whether the induced signal VRs exceeds the reference threshold voltage Vcomp in each interval. And a function for determining the rotation state of the stepping motor 108 (whether it has rotated, the degree of energy margin of the main drive pulse P1, etc.) or the like. In addition, the control circuit 103 has a function of determining the level of the battery 112 voltage based on the pattern of the section in which the induced signal VRs exceeding the reference threshold voltage Vcomp is detected.

  The rotation detection circuit 107 is a known rotation detection circuit described in Patent Document 1, and determines the level of the induced signal VRs generated by free vibration immediately after the stepping motor 109 is driven to rotate, and outputs a predetermined reference threshold voltage Vcomp. The generation time point of the induced signal VRs exceeding is detected. When the stepping motor 109 rotates, such as when the rotor of the stepping motor 109 moves at a certain speed or more, the induced signal VRs exceeding the reference threshold voltage Vcomp is detected, and the stepping motor 109 does not rotate. As described above, when the rotor of the stepping motor 109 does not move above a certain speed, the induced signal VRs exceeding the reference threshold voltage Vcomp is not detected. The reference threshold voltage Vcomp is used to determine a rotation state such as rotation or non-rotation and change a drive pulse (pulse control) according to a combination pattern of sections in which induced signals VRs exceeding the reference threshold voltage Vcomp are detected. Is set to a value that allows

  Here, the oscillation circuit 101 and the frequency dividing circuit 102 constitute a signal generation unit, and the analog display unit 110 constitutes a display unit. The rotation detection circuit 107 and the detection section determination circuit 111 constitute a rotation detection unit. The main drive pulse generation circuit 104, the correction drive pulse generation circuit 108, and the demagnetization pulse generation circuit 114 constitute a drive pulse generation unit. The motor drive circuit 106 constitutes a motor drive unit. The oscillation circuit 101, the frequency dividing circuit 102, the pulse down counter circuit 105, the control circuit 103, the main drive pulse generation circuit 104, the correction drive pulse generation circuit 108, the demagnetization pulse generation circuit 114, and the motor drive circuit 106 constitute a control unit. Yes. In addition, the oscillation circuit 101, the frequency dividing circuit 102, the pulse down counter circuit 105, the control circuit 103, the main drive pulse generation circuit 104, the correction drive pulse generation circuit 108, the demagnetization pulse generation circuit 114, the motor drive circuit 106, and the rotation detection circuit 107 The detection interval determination circuit 111 constitutes a stepping motor control circuit.

FIG. 2 is a configuration diagram of the stepping motor 109 used in each embodiment of the present invention, and shows an example of a timepiece stepping motor generally used in an analog electronic timepiece.
In FIG. 2, a stepping motor 109 is wound around a stator 201 having a rotor accommodating through hole 203, a rotor 202 rotatably disposed in the rotor accommodating through hole 203, a magnetic core 208 joined to the stator 201, and a magnetic core 208. A rotated coil 209 is provided. When the stepping motor 108 is used in an analog electronic timepiece, the stator 201 and the magnetic core 208 are fixed to a base plate (not shown) by screws or caulking (not shown) and joined to each other. The coil 209 has a first terminal OUT1 and a second terminal OUT2.

  The rotor 202 is magnetized to two poles (S pole and N pole). A plurality of (two in this embodiment) notch portions (outer notches) 206 and 207 are provided at positions facing each other across the rotor accommodating through hole 203 at the outer end portion of the stator 201 formed of a magnetic material. Is provided. Saturable portions 210 and 211 are provided between the outer notches 206 and 207 and the rotor accommodating through hole 203.

  The saturable portions 210 and 211 are configured not to be magnetically saturated by the magnetic flux of the rotor 202 but to be magnetically saturated when the coil 209 is excited to increase the magnetic resistance. The through hole 203 for accommodating the rotor has a circular hole shape in which a plurality of (two in the present embodiment) half-moon-shaped notches (inner notches) 204 and 205 are integrally formed at the opposing portion of the through hole having a circular outline. It is configured.

  The notches 204 and 205 constitute a positioning part for determining the stop position of the rotor 202. In a state where the coil 209 is not excited, the rotor 202 has a position corresponding to the positioning portion as shown in FIG. 2, in other words, a line segment connecting the notches 204 and 205 with the magnetic pole axis A of the rotor 202. Is stably stopped at a position orthogonal to the angle (angle θ0 position).

  Now, a rectangular-wave drive pulse of one polarity is supplied from the motor drive circuit 106 between the terminals OUT1 and OUT2 of the coil 209 (for example, the first terminal OUT1 side is positive and the second terminal OUT2 side is negative). When a current i flows in the direction of the arrow 2, a magnetic flux is generated in the stator 201 in the direction of the broken line arrow. As a result, the saturable portions 210 and 211 are saturated and the magnetic resistance is increased, and then the rotor 202 rotates 180 degrees in the direction of the arrow in FIG. 2 due to the interaction between the magnetic pole generated in the stator 201 and the magnetic pole of the rotor 202. Then, the magnetic pole axis A stops stably at the angle θ1 position. Incidentally, the rotation direction (counterclockwise direction in FIG. 2) for causing the normal operation (in this embodiment, since it is an analog electronic timepiece to move the hand) by rotating the stepping motor 109 is a positive direction. The reverse (clockwise direction) is the reverse direction.

  Next, a drive pulse having a reverse polarity is supplied from the motor drive circuit 107 to the terminals OUT1 and OUT2 of the coil 209 (the first terminal OUT1 side is a negative electrode and the second terminal OUT2 is so as to have a reverse polarity to the drive). When a current is passed in the opposite arrow direction in FIG. 2, a magnetic flux is generated in the stator 201 in the opposite arrow direction. As a result, the saturable portions 210 and 211 are first saturated, and then the rotor 202 rotates 180 degrees in the same direction as described above due to the interaction between the magnetic poles generated in the stator 201 and the magnetic poles of the rotor 202, and the magnetic pole axis A Stops stably at the angle θ0 position.

Thereafter, by supplying signals with different polarities (alternating signals) to the coil 209 in this way, the above operation is repeated, and the rotor 202 can be continuously rotated 180 degrees in the direction of the arrow. It is configured as follows.
In the first and second embodiments, a plurality of types of main drive pulses P1n and correction drive pulses P2 having different energy are used as drive pulses. The rank n of the main drive pulse P1n is a positive integer representing the magnitude of energy, and has a plurality of ranks from a minimum value 1 to a maximum value m, and the drive pulse energy increases as the value of n increases. Yes. The correction drive pulse P2 is a large energy pulse that can forcibly rotate an overload, and its energy is set to be larger than each main drive pulse P1.

  FIG. 3 is a timing chart common to the first embodiment of the present invention. The voltage state of the battery 112 and the induced signal VRs detected by the detection section determination circuit 111 are based on the first section T1 to the third section T3. Pattern (whether the first interval T1, the second interval T2, the third interval T3) whether or not the threshold voltage Vcomp is exceeded, the rotation state of the stepping motor 109, the rotation trajectory of the rotor 202, the generation timing of the induced signal VRs, the main drive pulse A pulse control operation such as whether or not to maintain or change P1 is also shown.

The detection section T is divided into a first section T1, a second section T2, and a third section T3. A predetermined time immediately after driving by the main drive pulse P1 is a first interval T1, a predetermined time after the first interval T1 is a second interval T2, and a predetermined time after the second interval is a third interval T3. In this way, the entire detection section T starting immediately after driving by the main drive pulse P1 is divided into a plurality of sections (three sections T1 to T3 in the first to third embodiments). It should be noted that no mask interval is provided in which the induced signal VRs is not detected.
When the XY coordinate space where the main magnetic pole A of the rotor 202 is located by rotation of the rotor 202 is divided into the first quadrant to the fourth quadrant, the first section T1 to the third section T3 are expressed as follows. Can do.

  That is, when the load is in a normal load state and the voltage of the battery 112 is a predetermined voltage (a voltage at which the stepping motor 109 exhibits “reasonable rotation”), the first section T1 is a space around the rotor 202. A section for determining the first forward rotation situation of the rotor 202 and a section for judging the first reverse rotation situation in the second quadrant and the third quadrant, and a second section T2 is the first reverse rotation of the rotor 202 in the third quadrant. The third section T3 is a section for determining the second forward rotation situation and the second reverse rotation situation of the rotor 202 in the third quadrant. Here, the normal load means a load that is driven at a normal time, and in the present embodiment, a load when driving the time hand (hour hand, minute hand, second hand) of the analog display unit 110 is a normal load. .

  P1 represents a main drive pulse and also represents a period driven by the main drive pulse P1. In an XY coordinate section centered on the rotation center of the rotor 202, a is a region where the rotor 202 is first rotated in the positive direction in the second quadrant by driving with the main drive pulse P1, and b is first positive in the third quadrant. In the third quadrant, c is a region that rotates in the reverse direction first, and d is a region that rotates in the positive direction for the second time in the third quadrant. In the third quadrant, e is a region that rotates in the reverse direction for the second time.

  For example, in FIG. 3, in the stepping motor control circuit according to each embodiment, the induced signal VRs generated in the region b is detected in the first section T1 when the voltage of the battery 112 indicates “a moderate margin of rotation”. The induced signal VRs generated in the region c is detected in the first interval T1 and the second interval T2, and the induced signal VRs generated in the region d is detected in the second interval T2 and the third interval T3, and is generated in the region e. The induced signal VRs is detected in the third section T3.

  In addition, when the battery 112 is a voltage lower than the voltage indicating the “reasonable margin rotation” by a predetermined value (the voltage indicating that the stepping motor 109 is “a little marginal rotation”), the induced signal VRs generated in the region a is the first. The induced signal VRs detected in the first section T1 and generated in the area b is detected in the first section T1 and the second section T2, and the induced signal VRs generated in the area c is detected in the second section T2 and the third section T3. The induced signal VRs generated in the region d is detected in the third section T3.

Similarly, the pattern of the induced signal VRs corresponding to the relationship between the load and the voltage of the secondary battery 112 is detected as shown as “rotation without margin” and “non-rotation” in which the stepping motor 109 did not rotate. It will be.
The control circuit 103 performs pulse control such as rank-up, rank maintenance, rank-down of the main drive pulse P1, drive by the correction drive pulse P2, and the like according to the pattern of the induced signal VRs.
The determination value of the induced signal VRs in each of the sections T1 to T3 is represented as “1” when the induced signal VRs exceeds the reference threshold voltage Vcomp, and “0” when the induced signal VRs does not exceed the reference threshold voltage Vcomp. ing. A section in which the determination value may be “1” or “0” is represented as “1/0”.

  The pattern (1/0, 0, 0) shows the state in which the voltage of the battery 112 is the lowest in the example of FIG. 3, and the state in which the stepping motor 109 does not rotate in the current driving by the main driving @pulse P1 (“non- Rotation "). Since the stepping motor 109 did not rotate, the control circuit 103 forcibly rotates the stepping motor 109 by driving with the correction driving pulse P2, and the main driving pulse P1 is ranked one rank at the time of driving with the next main driving pulse P1. Pulse control is performed so that the main drive pulse P1 with large energy is changed (ranked up) and driven.

  In the pattern (1/0, 0, 1), the voltage of the battery 112 is the next lower than that of the pattern (1/0, 0, 0), and the stepping motor 109 is rotated by the main driving pulse P1, but the main driving pulse P1 is rotated. This indicates that the rotation of the drive pulse P1 has no margin (“rotation without margin”). Since the control circuit 103 rotates without rotation, the control circuit 103 performs pulse control so that the main drive pulse P1 is driven up one rank at the next drive without performing the drive with the correction drive pulse P2.

  In the pattern (1, 1, 1/0), the voltage of the battery 112 is next lower than that of the pattern (1/0, 0, 1), and the stepping motor 109 is rotated by the current driving by the main driving pulse P1, but the main driving pulse P1 is rotated. It shows that the rotation of the drive pulse P1 has a little margin ("rotation with a little margin"). Since the control circuit 103 has rotated but has a slight margin, the rank of the main drive pulse P1 is maintained without being ranked up.

  In the pattern (0, 1, 1/0), the voltage of the battery 112 is the highest, the stepping motor 109 is rotated by the current driving by the main driving pulse P1, and the energy of the main driving pulse P1 is rotated with an appropriate margin (“ It shows that the rotation is a moderate margin. Since the control circuit 103 is rotating with a moderate margin, the rank is not increased, and the rank of the main drive pulse P1 is maintained until a predetermined condition occurs as will be described later. The control circuit 103 changes the main drive pulse to the main drive pulse P1 that is one rank lower (rank down) when the drive with the main drive pulse P1 of the same energy has obtained a sufficient amount of rotation continuously for a predetermined number of times. To do.

FIG. 4 is a timing chart for explaining the operation of each embodiment of the present invention.
In FIG. 4, O1 and O2 are terminals OUT1 and OUT2 of the coil 209 of the stepping motor 109, respectively. When the stepping motor 109 can be driven and rotated by the main drive pulse P11 (when the induced signal VRs pattern is other than (1/0, 0, 0)), the main drive pulse is alternately applied to the terminals O1 and O2. P1 is supplied and the stepping motor 109 is driven to rotate.

When the stepping motor 109 does not rotate as a result of driving with the main drive pulse P1 (in the case of the induced signal VRs pattern (1/0, 0, 0)), the correction drive pulse P2 (in the example of FIG. 4, the stepping motor 109 is used). The stepping motor 109 is driven and forcedly rotated by a correction driving pulse P2) constituted by a forced rotation driving pulse P21 for forcibly rotating the stepping motor 109 and a braking pulse Pr for braking the stepping motor 109. The braking pulse Pr is not always necessary.
Thereafter, the stator 201 and the magnetic core 208 of the stepping motor 109 are demagnetized by driving the stepping motor 109 with a demagnetizing pulse PE having a polarity different from that of the correction driving pulse P2. The next drive is driven by the main drive pulse P12 whose energy is increased by one rank.

FIG. 5 is a timing chart for explaining the operation of the first and third embodiments of the present invention.
In FIG. 5, three types of rectangular wave demagnetization pulses PE1 to PE3 having different drive time widths (demagnetization pulse PE1 <demagnetization pulse PE2 <demagnetization pulse PE3) are prepared as demagnetization pulses PE. ing. Immediately after being driven by the correction drive pulse P2 constituted by the forced rotation drive pulse P21 and the braking pulse Pr, the drive is performed by the demagnetization pulse PE having a polarity different from that of the correction drive pulse P2. Here, the driving time width is a time width for which the degaussing pulse PE is substantially driven. In the case of a rectangular wave, the width of the rectangular wave corresponds to the width between driving. The sum of the times when the plurality of element pulses constituting the tooth waveform substantially contribute to driving (the sum of the low level times in each element pulse) corresponds to the driving time width.

  When the voltage of the battery 112 is within a predetermined second voltage range, the battery 112 is driven by the second demagnetizing pulse PE2 having a second driving time width, and the voltage of the battery 112 exceeds the second voltage. In the case of the range, it is driven by the first demagnetizing pulse PE1 having the first time width narrower than the second driving time width (the pulse width is narrow in the example of FIG. 5), and the voltage of the battery 112 is less than the second voltage. In the case of the third voltage range, the third demagnetizing pulse PE3 having a third time width wider than the second driving time width (in the example of FIG. 5, the pulse width is wide) is used.

  That is, when the voltage of the battery 112 is within the range of the second voltage, the energy of the demagnetizing pulse PE is within the predetermined range, so the second demagnetizing pulse PE2 having the second driving time width (demagnetizing pulse PE with energy within the predetermined range). Keep driving. When the voltage of the battery 112 is the first voltage outside the second voltage range (in other words, when the energy of the degaussing pulse PE is outside the predetermined range), the first time width within the predetermined range is the first. The drive is changed to the demagnetizing pulse PE1. In addition, when the voltage of the battery 112 is the third voltage outside the second voltage range (in other words, when the energy of the degaussing pulse PE is outside the predetermined range), the third time width within the predetermined range is set. The third demagnetizing pulse PE3 is changed to drive.

  Thus, the first demagnetizing pulse, the second degaussing pulse, and the third degaussing pulse are associated with the first voltage, the second voltage, and the third voltage, respectively. Further, the pattern of the induced signal VRs obtained when the previous driving is performed by the main driving pulse P1, the third demagnetizing pulse PE3 is associated with (1/0, 0, 1), and (1, 1, 1 / 0) is associated with the second degaussing pulse PE2, and (0, 1, 1/0) is associated with the first degaussing pulse PE1. As described above, the storage unit (see FIG. 5) in the control circuit 103 is associated with the relationship between the voltage of the battery 112 and the type of the demagnetizing pulse, or the relationship between the pattern of the induced signal VRs and the type of the demagnetizing pulse PE. (Not shown), and the demagnetization pulse changing control can be performed using this.

Hereinafter, the operation of the first exemplary embodiment of the present invention will be described in detail with reference to FIGS.
In FIG. 1, an oscillation circuit 101 generates a signal having a predetermined frequency, and a frequency dividing circuit 102 divides the signal generated by the oscillation circuit 101 to generate a clock signal serving as a time reference, and a pulse down counter circuit 105 And output to the control circuit 103.
The control circuit 103 counts the clock signal and performs a time counting operation, and outputs a main driving pulse control signal to the main driving pulse generation circuit 104 so as to rotationally drive the stepping motor 109 every time a predetermined time is counted.

  The main drive pulse generation circuit 104 outputs a main drive pulse of energy corresponding to the main drive pulse control signal from among a plurality of types of main drive pulses P1 having different energies to the motor drive circuit 106. The motor drive circuit 106 rotationally drives the stepping motor 109 with the main drive pulse P 1 from the main drive pulse generation circuit circuit 104. The stepping motor 109 rotates the time hand 115 of the analog display unit 110. Thus, when the stepping motor 109 rotates normally, the time hand 115 is driven and the current time is displayed on the analog display unit 110 as needed.

The rotation detection circuit 107 detects the induced signal VRs exceeding the reference threshold voltage Vcomp in the detection section T immediately after the stepping motor 109 is driven by the main drive pulse P1. The detection interval determination circuit 111 determines to which interval T1 to T3 the induced signal VRs exceeding the reference threshold voltage Vcomp detected by the rotation detection circuit 107 belongs, and outputs a detection signal representing the pattern of the induced signal VRs to the control circuit. To 103.
The control circuit 103 performs the pulse control shown in FIG. 3 based on the pattern of the induced signal VRs from the detection section determination circuit 111.

  As shown in FIG. 4, the control circuit 103 forcibly rotates the stepping motor 109 with the correction drive pulse P2 when the pattern of the induced signal VRs is (1/0, 0, 0) indicating non-rotation. Thereafter, driving is performed using a degaussing pulse PE of energy corresponding to the pattern of the induced signal VRs obtained when the driving is performed by the main driving pulse P1 last time (before rotation is not rotated).

  In the present embodiment, as shown in FIG. 5, when the pattern of the induced signal VRs obtained when the previous driving is performed by the main driving pulse P1 is (1/0, 0, 1), the power supply voltage is low. It is determined to drive using the demagnetizing pulse PE3 having the widest driving time width. When (1, 1, 1/0), the power supply voltage is determined to be medium, and the degaussing pulse PE2 having an intermediate driving time width is used. When (0, 1, 1/0), it is determined that the power supply voltage is high, and the demagnetizing pulse PE1 with the narrowest driving time width is used for driving. Thereby, the stepping motor 109 is demagnetized without rotating.

  On the other hand, while the control circuit 103 is input from the detection section determination circuit 111, the pattern (0, 1, 1/0) indicating an appropriate margin of rotation when driven by the main drive pulse P1 having the same energy, No reset signal is output to the pulse down counter circuit 105. Accordingly, when the pulse down counter circuit 105 is driven by the main drive pulse P1 having the same energy, a pattern (0, 1, 1/0) indicating an appropriate margin of rotation is continuously detected a predetermined number of times (PCD number). In the case of a failure, the predetermined number of times is counted without being reset.

  When the pulse down counter circuit 105 counts the predetermined number of times, the pulse down counter circuit 105 outputs a pulse down signal for pulsing down the main drive pulse P1 to the main drive pulse generation circuit 104 and resets its count value. In response to the pulse down signal, the main drive pulse generation circuit 104 changes the main drive pulse P1 to the main drive pulse P1 down by one rank and outputs it to the motor drive circuit 106. The motor drive circuit 106 rotationally drives the stepping motor 109 with the main drive pulse P1 from the main drive pulse generation circuit 104. This saves power.

  In the first embodiment, a rectangular wave-shaped demagnetizing pulse PE is used as shown in FIG. 5, but a comb-like degaussing pulse PE may be used as shown in FIG. In FIG. 6, the comb-shaped demagnetizing pulse PE is composed of narrow element pulses. Also in the example of FIG. 6, three types of comb-shaped demagnetizing pulses PE1 to PE3 having different driving time widths (the total of the low-level time widths of the element pulses) are prepared as the demagnetizing pulses PE.

  The degaussing pulse PE1 is composed of one element pulse, and the degaussing pulses PE2 and PE3 are composed of a plurality of element pulses (two degaussing pulses PE2 and three degaussing pulses PE3). The magnitude relation of the drive time width of each demagnetizing pulse PE1 to PE3 is demagnetizing pulse PE1 <demagnetizing pulse PE2 <demagnetizing pulse PE3. The drive time width of the degaussing pulse PE is performed by changing at least one of the number of element pulses or the duty ratio of the element pulses. Using the comb-shaped degaussing pulses PE1 to PE3, the same drive as in FIG. 5 is performed.

  As described above, according to the first embodiment of the present invention, even when a situation occurs in which the energy of the degaussing pulse PE varies greatly, the degaussing pulse having an appropriate energy after driving with the correction driving pulse P2. Since it can be driven by PE, the stepping motor 109 can be degaussed well without being rotated by the demagnetizing pulse PE.

  In the first embodiment, the magnitude of the power supply voltage is determined based on the pattern of the induced signal VRs generated by the free vibration of the stepping motor 109 when driven by the main drive pulse P1, and the induced signal Since it is configured to be demagnetized by being driven by a demagnetizing pulse PE corresponding to the VRs pattern, it is not necessary to provide a dedicated circuit for voltage detection or the like, and the configuration is simple.

  In the first embodiment, a plurality of types of main drive pulses P1 having different energy are used as the main drive pulse P1, but a plurality of types of main drive pulses P1 are not necessarily required. But you can. That is, one type of main drive pulse P1 and correction drive pulse P2 may be used.

Next, a second embodiment of the present invention will be described. The second embodiment is the same as the first embodiment with respect to FIGS. In the second embodiment, as in the first embodiment, the rotation state is determined by the pattern of the induced signal VRs. However, the two rotation states indicating whether the rotation has occurred are determined. You may comprise.
FIG. 7 is a flowchart showing the processing of the second embodiment of the present invention, and mainly shows the processing of the control circuit 103.

  FIG. 8 is a timing chart for explaining the operation of the second embodiment of the present invention. In FIG. 8, as in the first embodiment, as the demagnetizing pulse PE, three types of rectangular wave demagnetizing pulses PE1 to PE3 having mutually different driving time widths (the magnitude relationship of the driving time widths is the degaussing pulse PE1 <demagnetization. Pulse PE2 <demagnetizing pulse PE3) is prepared. Immediately after being driven by the correction drive pulse P2 constituted by the forced rotation drive pulse P21 and the braking pulse Pr, the drive is performed by the demagnetization pulse PE having a polarity different from that of the correction drive pulse P2.

In the second embodiment, in addition to the correction drive pulse P2, plural types (four types in the present embodiment) of main drive pulses P1 having energy smaller than the correction drive pulse P2 and different from each other are prepared. Has been.
If the stepping motor does not rotate in the drive by the main drive pulse P1, the drive by the demagnetizing pulse PE is performed after the drive by the correction drive pulse P2, but the current drive is non-rotated. The demagnetization pulse PE is changed according to the rank of the main drive pulse P1 (in other words, the main drive pulse P1 driven immediately before the correction drive pulse P2 is driven).

As the main drive pulse P1, the first main drive pulse P11 having the narrowest pulse width, the second main drive pulse P12 having a wider pulse width than the first main drive pulse P11, and the first pulse having a wider pulse width than the second main drive pulse P12. A third main drive pulse P13 and a fourth main drive pulse P14 having a wider pulse width than the third main drive pulse P13 are prepared.
The first main driving pulse P11 and the second main driving pulse P12 are associated with the first degaussing pulse PE1, the third main driving pulse P13 is associated with the second degaussing pulse PE2, and the fourth main driving pulse P14 is associated with the first demagnetizing pulse PE1. Three demagnetization pulses PE3 are associated with each other, and the demagnetization pulse PE corresponding to the energy rank n of the main drive pulse P1 that has been non-rotated by driving this time is selected and driven. The correspondence relationship between the types of the main drive pulse P1 and the demagnetization pulse PE is stored in advance in a storage unit (not shown) of the control unit 103, and the demagnetization pulse PE can be changed and controlled using this. .

  For example, when the main drive pulse P1 driven this time is the third main drive pulse P13, the energy of the demagnetization pulse PE is within a predetermined range, and therefore the second demagnetization pulse PE2 (within the predetermined range) It is driven by an energy demagnetizing pulse PE). When the main drive pulse P1 driven this time is the first main drive pulse P11 and the second main drive pulse P12, the demagnetization pulses PE2 and PE3 are outside the predetermined range, so the energy is within the predetermined range. The first demagnetizing pulse PE1 having a driving time width is used for driving. Further, when the main drive pulse P1 driven this time is the fourth main drive pulse P14, the demagnetization pulses PE2 and PE1 are outside the predetermined range, so the third drive time width of the third drive time width in which the energy is within the predetermined range. It is driven by three demagnetizing pulses PE1.

Hereinafter, the second embodiment of the present invention will be described with reference to FIGS. 1 to 4, 7, and 8, with respect to differences from the first embodiment.
When the control circuit 103 determines that a predetermined drive cycle (for example, 1 second cycle) has come (step S900 in FIG. 7), the main drive is performed so that the stepping motor 109 is driven by the main drive pulse P1n of rank n at that time. A main drive pulse control signal is output to the pulse generation circuit 104 (step S901). The main drive pulse generation circuit 104 is driven by the main drive pulse P1n having an energy rank corresponding to the main drive pulse control signal via the motor drive circuit 106.

The rotation detection circuit 107 detects the induced signal VRs exceeding the reference threshold voltage Vcomp generated by the stepping motor 109 in the detection section T immediately after the stepping motor 109 is driven. Based on the induced signal VRs exceeding the reference threshold voltage Vcomp detected by the rotation detection circuit 107, the detection section determination circuit 111 outputs an induced signal VRs pattern representing the rotation state of the stepping motor 109 to the control circuit 103 as a detection signal. To do.
As in FIG. 3, the control circuit 103 determines the rotation state of the stepping motor 109 based on the detection signal from the detection section determination circuit 111 (step S902).

  When the control circuit 103 determines in step S902 that the stepping motor 109 is not rotating (when the pattern is (1/0, 0, 0)), the correction drive pulse control signal is driven so as to be driven by the correction drive pulse P2. Is output to the correction drive pulse generation circuit 108 (step S903). The correction drive pulse generation circuit 108 is forcibly rotated by the correction drive pulse P2 through the motor drive circuit 106 in response to the correction drive pulse control signal.

  Next, the control circuit 103 selects the demagnetizing pulse PE corresponding to the rank n of the main driving pulse P1 driven this time (step S904). In the present embodiment, when the energy rank of the main drive pulse P1 that has been non-rotated this time is the first main drive pulse P11 and the second main drive pulse P12, the first demagnetizing pulse PE1 is used for driving. In the case of the third main drive pulse P13, the second demagnetizing pulse PE2 is used for driving. In the case of the fourth main drive pulse P14, the third demagnetizing pulse PE3 is used for driving.

  Next, when the rank of the main drive pulse P1 is not the maximum rank max (the fourth main drive pulse P14 in the present embodiment), the control circuit 103 increases the rank of the main drive pulse P1 by 1 (step S906), The degaussing pulse control signal is output to the degaussing pulse generation circuit 114 so as to drive the stepping motor 109 using the determined degaussing pulse PE, and the process returns to the processing step S900 (step S907).

The degaussing pulse generation circuit 114 is driven by the corresponding degaussing pulse PE via the motor driving circuit 106 in response to the demagnetizing pulse control signal. Thereby, the stepping motor 109 is degaussed satisfactorily without rotating. In the next processing step S901, driving is performed by the main drive pulse P1 ranked up here.
If the rank of the main drive pulse P1 is the maximum rank max (fourth main drive pulse P14 in the present embodiment) in process step S905, the control circuit 103 immediately proceeds to process step S907.

On the other hand, if the control circuit 103 determines that the pattern of the induced signal VRs generated by the rotation of the stepping motor 109 is “rotation with an appropriate margin” (0, 1, 1/0) in the processing step S902, the pulse down It is determined whether the counter circuit 105 has counted a predetermined value (for example, 60 times) (step S908).
When the pulse down counter circuit 105 does not count the predetermined value, the control circuit 103 adds 1 to the count value of the pulse down counter circuit 105 and then returns to the processing step S900 (step S909).

  When the control circuit 103 determines in the processing step S908 that the pulse down counter 105 counts a predetermined value, that is, the pattern (0, 1, 1) is continuously generated a predetermined number of times by driving with the main drive pulse P1 having the same energy. If it is determined that (/ 0) is obtained, the pulse down counter circuit 105 is reset and the count value is cleared to 0 (step S910).

  Next, when it is determined that the current rank of the main drive pulse P1 is not the minimum value min (step S911), the control circuit 103 lowers the rank of the main drive pulse P1 by one rank and returns to the processing step S900 (step S912). If the control circuit 103 determines in process step S911 that the current rank of the main drive pulse P1 is the minimum value, the control circuit 103 returns to process step S900 without lowering the rank of the main drive pulse P1.

  In the second embodiment, the rectangular wave-shaped degaussing pulse PE is used as shown in FIG. 8, but a comb-like degaussing pulse PE may be used as shown in FIG. In FIG. 9, the comb-shaped demagnetizing pulse PE is composed of narrow element pulses. Also in the example of FIG. 9, three types of comb-shaped demagnetization pulses PE1 to PE3 having different driving time widths (the total of the low-level time widths of the element pulses) are prepared as the demagnetization pulses PE.

  The degaussing pulse PE1 is composed of one element pulse, and the degaussing pulses PE2 and PE3 are composed of a plurality of element pulses (two degaussing pulses PE2 and three degaussing pulses PE3). The magnitude relation of the drive time width of each demagnetizing pulse PE1 to PE3 is demagnetizing pulse PE1 <demagnetizing pulse PE2 <demagnetizing pulse PE3. The drive time width of the degaussing pulse PE is performed by changing at least one of the number of element pulses or the duty ratio of the element pulses.

  The first main driving pulse P11 and the second main driving pulse P12 are associated with the first degaussing pulse PE1, the third main driving pulse P13 is associated with the second degaussing pulse PE2, and the fourth main driving pulse P14 is associated with the first demagnetizing pulse PE1. Three demagnetizing pulses PE3 are associated with each other, and the demagnetizing pulse PE corresponding to rank n of the main driving pulse P1 that has been driven and is not rotated is selected and driven. Using the comb-shaped demagnetizing pulses PE1 to PE3, the same driving as described with reference to FIG. 8 is performed.

As described above, according to the second embodiment of the present invention, even when a situation occurs in which the energy of the degaussing pulse PE fluctuates greatly, the degaussing pulse having an appropriate energy after driving with the correction driving pulse P2. Since it can be driven by PE, the stepping motor 109 can be degaussed well without rotating.
Further, in the second embodiment, the magnitude of the power supply voltage is determined based on the rank of the main drive pulse P1 driven this time, and driven by the demagnetizing pulse PE corresponding to the rank of the main drive pulse P1. Since it is configured to demagnetize, it is not necessary to provide a dedicated circuit for voltage detection or the like, and the configuration is simple.

  In the second embodiment, as in the first embodiment, the rotation state of the stepping motor is determined based on the pattern of the induced signal VRs. However, the reference threshold voltage within the detection section T is determined. It may be configured to detect whether or not an induced signal Vrs exceeding Vomp is generated, and to make a determination based on two types of rotation and non-rotation.

FIG. 10 is a block diagram of the third embodiment of the present invention, in which the same parts as those in FIG. The third embodiment includes a voltage detection circuit 113 that detects the voltage of the battery 112 serving as a power source and outputs a voltage detection signal corresponding to the voltage in order to determine a demagnetization pulse of appropriate energy. .
FIG. 11 and FIG. 12 are flowcharts showing the processing of the third embodiment of the present invention, mainly showing the processing of the control circuit 103.
2 to 6 are also applied to the third embodiment.

Hereinafter, with reference to FIGS. 2 to 6 and FIGS. 10 to 12, the operation of the third embodiment of the present invention will be described with respect to portions that are different from the first and second embodiments.
In the third embodiment, as in the second embodiment, the rotation state of the stepping motor 109 is the same as that in the first and second embodiments. Is determined based on the pattern of the induced signal VRs. However, it is detected whether or not the induced signal Vrs exceeding the reference threshold voltage Vomp is generated in the detection section T, and the determination is made based on two types of rotation and non-rotation. You may comprise as follows.

The control circuit 103 performs the degaussing pulse determination process of FIG. 11 every time a predetermined voltage measurement period comes.
In FIG. 11, when the control circuit 103 determines that a predetermined voltage measurement period has arrived (step S500), the control circuit 103 outputs a voltage measurement control signal to the voltage detection circuit 113 to measure the voltage of the battery 112 as a power source ( Step S501).
The voltage detection circuit 113 measures the voltage of the battery 112 in response to the voltage measurement control signal, and outputs the measured voltage to the control circuit 103 as a voltage detection signal.
Next, the control circuit 103 determines a degaussing pulse PE corresponding to the voltage measured by the voltage detection circuit 113 (step S502).

  In the third embodiment, as shown in FIG. 5, when the voltage of the battery 112 is within the range of the second voltage, the energy of the demagnetization pulse PE is within the predetermined range. It is driven by PE (demagnetizing pulse PE with energy within a predetermined range). When the voltage of the battery 112 is the first voltage outside the second voltage range (in other words, when the energy of the degaussing pulse PE is outside the predetermined range), the degaussing pulse having the first time width within the predetermined range. Change to PE1 and drive. In addition, when the voltage of the battery 112 is the third voltage outside the second voltage range (in other words, when the energy of the degaussing pulse PE is outside the predetermined range), the third time width within the predetermined range is set. The drive is changed to the demagnetizing pulse PE3.

  Thus, the first demagnetizing pulse, the second degaussing pulse, and the third degaussing pulse are associated with the first voltage, the second voltage, and the third voltage, which are the voltages of the battery 112, respectively. The relationship between the voltage of the battery 112 and the type of degaussing pulse is stored in association in a storage unit (not shown) in the control circuit 103, and the demagnetizing pulse change control is performed using this. Can do.

On the other hand, when the control circuit 103 determines that a predetermined drive cycle (for example, 1 second cycle) has arrived, the control circuit 103 controls to drive the stepping motor 109 by the main drive pulse P1n of rank n at that time. Then, the rotation state of the stepping motor 109 is determined based on the pattern of the induced signal VRs (steps S900 to S902).
When the control circuit 103 determines in step S902 that the stepping motor 109 is not rotating (in the case where the pattern is (1/0, 0, 0)), the control circuit 103 performs control so that it is driven by the correction drive pulse P2, and then performs processing. The process after step S905 is performed.

On the other hand, when the control circuit 103 determines that the pattern of the induced signal VRs generated by the rotation of the stepping motor 109 is “rotation with an appropriate margin” (0, 1, 1/0) in processing step S902, the processing step The processing after S908 is performed. The above process is repeated at a predetermined cycle.
As described above, according to the third embodiment of the present invention, even when a situation occurs in which the energy of the degaussing pulse PE varies greatly, the degaussing pulse having an appropriate energy after being driven by the correction driving pulse P2. Since it can be driven by PE, the stepping motor 109 can be degaussed well without rotating.

  In the third embodiment, since the power supply voltage is detected using the voltage detection circuit 113 and driven using the demagnetizing pulse PE corresponding to the voltage, the induced honor VRs are not necessarily used. It is not necessary to perform pulse control based on the pattern. In addition, a plurality of types of main drive pulses P1 are not necessarily required, and one type may be used. That is, it may be configured to drive by the demagnetizing pulse PE corresponding to the voltage of the battery 112 after driving the correction driving pulse by using one type of main driving pulse P1 and the correction driving pulse PE.

  As described above, the stepping motor control circuit according to each embodiment of the present invention includes the battery 112 as a power source, the rotation detection unit that detects the rotation state of the stepping motor 109, and the rotation detected by the rotation detection unit. Depending on the situation, the main driving pulse P1 or the correction driving pulse P2 having higher energy than the main driving pulse P1 is selected to drive the stepping motor 109, and the driving is performed by the demagnetizing pulse PE immediately after being driven by the correction driving pulse P2. A control unit that changes the energy of the demagnetizing pulse PE to a demagnetizing pulse PE having an energy within the predetermined range when it is determined that the energy of the demagnetizing pulse PE is out of the predetermined range.

Here, the control unit determines whether or not the energy of the demagnetizing pulse PE is outside a predetermined range based on the rotation state of the stepping motor 109 detected by the rotation detecting unit, and the energy of the demagnetizing pulse PE is within the predetermined range. When it is determined that it falls outside, it can be configured to change to a degaussing pulse PE having an energy within the predetermined range.
The rotation detection unit detects an induced signal VRs generated by rotation of the stepping motor 109 and exceeding a predetermined reference threshold voltage Vcomp in the detection section T divided into a plurality of sections T1 to T3, and the control section Can be configured to determine whether or not the energy of the degaussing pulse PE is out of a predetermined range based on the pattern of the induced signal VRs in each of the sections T1 to T3.

The controller may be configured to use a demagnetizing pulse PE having a narrower driving time width when the energy of the driving pulse for the load exceeds a predetermined value than when the energy does not exceed the predetermined value.
A plurality of types of demagnetization pulses PE having different driving time widths are prepared as the demagnetization pulse PE, and the pattern of the induced signal VRs and the type of the demagnetization pulse PE are associated with each other. The demagnetization pulse PE can be determined based on the pattern of the induced signal VRs detected by the rotation detection unit.

  In addition, as the main drive pulse P1, a plurality of types of main drive pulses P1 having different energies are prepared, and the control unit has a plurality of main drives having different energies according to the rotation state detected by the rotation detection unit. The stepping motor 109 is driven by selecting one of the pulses P1 or the correction drive pulse P2 having energy larger than each of the main drive pulses P1, and is driven by the demagnetizing pulse PE immediately after being driven by the correction drive pulse P2. The controller determines whether or not the energy of the degaussing pulse PE is out of the predetermined range based on the rank n of the selected main drive pulse P1, and determines that the energy of the degaussing pulse PE is out of the predetermined range. The demagnetizing pulse PE having energy within the predetermined range can be changed.

Further, the control unit can be configured to use a demagnetization pulse having a narrower driving time width when the rank n of the selected main drive pulse P1 does not exceed the predetermined rank, compared to when the rank exceeds the predetermined rank. .
A plurality of types of demagnetization pulses PE having different driving time widths are prepared as the demagnetization pulse PE, and the rank n of the main drive pulse P1 and the type of the demagnetization pulse PE are associated with each other, and the control unit The demagnetizing pulse PE can be determined based on the rank n of the main driving pulse P1 driven this time.

  In addition, a voltage detection unit that detects the voltage of the battery 112 as the power source is provided, and the control unit is configured such that the energy of the demagnetizing pulse PE is out of a predetermined range based on the voltage of the battery 112 detected by the voltage output unit. When it is determined whether or not the energy of the degaussing pulse PE is out of the predetermined range, the demagnetizing pulse PE having the energy within the predetermined range can be changed.

Further, the control unit is configured to use a demagnetization pulse having a narrower driving time width when the voltage of the battery 112 detected by the voltage detection unit exceeds a predetermined voltage than when the voltage does not exceed the predetermined voltage. Can do.
A plurality of types of demagnetization pulses PE having different driving time widths are prepared as the demagnetization pulse PE, and the voltage of the battery 112 and the type of the demagnetization pulse PE are associated with each other. The degaussing pulse PE can be determined based on the voltage of

The demagnetization pulse PE is composed of a plurality of element pulses, and the control unit is configured to change at least one of the number of element pulses or the duty ratio when changing the drive time width of the demagnetization pulse PE. Can do.
Accordingly, even when a situation occurs in which the energy of the demagnetizing pulse PE varies greatly, it is possible to drive with the demagnetizing pulse PE having an appropriate energy after driving with the correction driving pulse P2, without rotating the stepping motor. It becomes possible to demagnetize well.

  Further, since the movement of the present invention is characterized by comprising the stepping motor control circuit, even if a situation occurs in which the energy of the degaussing pulse PE greatly fluctuates, the movement after the driving with the correction driving pulse P2 occurs. It becomes possible to drive with an appropriate demagnetizing pulse PE, and it is possible to construct an analog electronic timepiece that can be degaussed well without rotating the stepping motor 109.

  Further, the analog electronic timepiece according to the embodiment of the present invention is characterized by including the movement, and therefore, even when a situation where the energy of the demagnetizing pulse PE greatly fluctuates occurs, the correction driving pulse P2 Since it is possible to drive with a demagnetizing pulse PE having an appropriate energy after driving with the stepping motor 109, it is possible to degauss well without rotating the stepping motor 109, and accurate hand movement becomes possible.

Each embodiment of the present invention can be applied to a stepping motor for driving a calendar or the like other than the time hand.
Moreover, although the example of the electronic timepiece has been described as an application example of the stepping motor, it can be applied to an electronic device using the motor.

The stepping motor control circuit according to the present invention is applicable to various electronic devices that use the stepping motor.
The movement and the analog electronic timepiece according to the invention can be applied to various analog electronic timepieces such as an analog electronic timepiece with various calendar functions such as an analog electronic wristwatch with a calendar function and an analog electronic table clock with a calendar function.

DESCRIPTION OF SYMBOLS 101 ... Oscillation circuit 102 ... Frequency division circuit 103 ... Control circuit 104 ... Main drive pulse generation circuit 105 ... Pulse down counter circuit 106 ... Motor drive circuit 107 ... Rotation detection circuit 108 ... Correction drive pulse generation circuit 109 ... Stepping motor 110 ... Analog display unit 111 ... Detection section determination circuit 112 ... Battery 113 ... Voltage detection circuit 114 ... Demagnetization pulse generation circuit 115: Time hand 116 ... Clock case 117 ... Movement 201 ... Stator 202 ... Rotor 203 ... Rotor accommodating through holes 204, 205 ... Notches (inner notches)
206, 207 ... Notch (outer notch)
208 ... Magnetic core 209 ... Coils 210, 211 ... Saturable portion OUT1 ... First terminal OUT2 ... Second terminal

Claims (11)

Power supply,
A rotation detector for detecting the rotation status of the stepping motor;
Immediately after driving the stepping motor by selecting a main drive pulse or a correction drive pulse whose energy is larger than that of the main drive pulse according to the rotation state detected by the rotation detection unit, and driving by the correction drive pulse A control unit driven by a demagnetizing pulse,
When the control unit determines that the energy of the degaussing pulse is outside a predetermined range, the control unit changes the demagnetizing pulse to an energy within the predetermined range.   The control unit determines whether or not the energy of the degaussing pulse is out of a predetermined range based on the rotation state of the stepping motor detected by the rotation detection unit, and when the energy of the degaussing pulse is out of the predetermined range. 2. The stepping motor control circuit according to claim 1, wherein when determined, the stepping motor control circuit changes to a degaussing pulse of energy within the predetermined range. The rotation detection unit detects an induced signal exceeding a predetermined reference threshold voltage generated by the rotation of the stepping motor in a detection section divided into a plurality of sections,
The stepping motor control circuit according to claim 2, wherein the control unit determines whether or not the energy of the degaussing pulse is out of a predetermined range based on a pattern of the induced signal detected in each section. . A plurality of types of demagnetization pulses having different driving time widths are prepared as the demagnetization pulses, and the induced signal pattern and the demagnetization pulse types are associated with each other.
The stepping motor control circuit according to claim 3, wherein the control unit determines the demagnetization pulse based on a pattern of an induced signal detected by the rotation detection unit. As the main drive pulse, a plurality of types of main drive pulses having different energy are prepared,
The control unit selects one of a plurality of main drive pulses having different energies according to the rotation state detected by the rotation detection unit or a correction drive pulse having energy larger than each main drive pulse, and performs the stepping. The motor is driven, and is driven by a demagnetizing pulse immediately after being driven by the correction driving pulse.
The control unit determines whether the energy of the degaussing pulse is out of a predetermined range based on the rank of the selected main driving pulse, and when determining that the energy of the degaussing pulse is out of the predetermined range, 2. The stepping motor control circuit according to claim 1, wherein the stepping motor control circuit is changed to a degaussing pulse having an energy within a predetermined range. A plurality of types of demagnetization pulses having different driving time widths are prepared as the demagnetization pulses, and the ranks of the main drive pulses and the types of the demagnetization pulses are associated with each other.
6. The stepping motor control circuit according to claim 5, wherein the control unit changes to a degaussing pulse corresponding to a rank of the main driving pulse driven this time. Comprising a voltage detector for detecting the voltage of the power supply;
The control unit determines whether the energy of the degaussing pulse is out of a predetermined range based on the voltage of the power source detected by the voltage output unit, and determines that the energy of the degaussing pulse is out of the predetermined range. 2. The stepping motor control circuit according to claim 1, wherein the stepping motor control circuit changes to a degaussing pulse of energy within the predetermined range. A plurality of types of demagnetization pulses with different driving time widths are prepared as the demagnetization pulses, and the power supply voltage and the demagnetization pulse types are associated with each other.
The stepping motor control circuit according to claim 7, wherein the control unit changes to a degaussing pulse corresponding to a voltage of the power source. The degaussing pulse is composed of a plurality of element pulses,
9. The stepping motor control circuit according to claim 1, wherein the control unit changes at least one of the number of the element pulses or the duty ratio when changing the driving time width of the degaussing pulse. 10. .   A movement comprising the stepping motor control circuit according to claim 1.   An analog electronic timepiece comprising the movement according to claim 10.

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